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• 1. [Article] Stream Temperature Management in the Tualatin Watershed: Is it Improving Salmonid Habitat?

  The purpose of this paper is to examine the literature from scientific and governmental entities that describes the problems with elevated stream temperatures in the Tualatin basin, the actions being taken ...

  Citation × Citation Citation Abstract Copy Title: Stream Temperature Management in the Tualatin Watershed: Is it Improving Salmonid Habitat? Author: Hennings, Raymond Banks Year: 2014 The purpose of this paper is to examine the literature from scientific and governmental entities that describes the problems with elevated stream temperatures in the Tualatin basin, the actions being taken to resolve those problems, and to assess whether these actions are meeting the goal of improving salmonid habitat in the basin. Elevated stream temperatures are considered a pollutant under the US Clean Water Act (Clean Water Act 1972, as amended) because increased stream temperatures can be harmful to native aquatic biota, particularly salmonid fish species that have evolved to use cold water (IMST 2004). Title: Stream Temperature Management in the Tualatin Watershed: Is it Improving Salmonid Habitat? Author: Hennings, Raymond Banks Year: 2014 The purpose of this paper is to examine the literature from scientific and governmental entities that describes the problems with elevated stream temperatures in the Tualatin basin, the actions being taken to resolve those problems, and to assess whether these actions are meeting the goal of improving salmonid habitat in the basin. Elevated stream temperatures are considered a pollutant under the US Clean Water Act (Clean Water Act 1972, as amended) because increased stream temperatures can be harmful to native aquatic biota, particularly salmonid fish species that have evolved to use cold water (IMST 2004). Close

• 2. [Article] Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance

  The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases ...

  Citation × Citation Citation Abstract Copy Title: Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance Author: Lee, Tae-Kyu, Chen, Zhiqiang, Guirguis, Cherif, Akinade, Kola Year: 2017 The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases with higher electric power condition, which brings the component into an elevated temperature environment, thus introducing another consideration factor for mechanical stability of interconnection joints. Since most of the shock performance data available were produced at room temperature, the effect of elevated temperature is of interest to ensure the reliability of the device in a mechanical shock environment. To achieve a stablea interconnect pound in a dynamic shock environment, the interconnections must tolerate mechanical strain, which is induced by the shock wave input and reaches the particular component interconnect joint. In this study, large body size (52.5 x 52.5 mm(2)) FCBGA components assembled on 2.4-mm-thick boards were tested with various isothermal pre-conditions and testing conditions. With a heating element embedded in the test board, a test temperature range from room temperature to 100A degrees C was established. The effects of elevated temperature on mechanical shock performance were investigated. Failure and degradation mechanisms are identified and discussed based on the microstructure evolution and grain structure transformations. Title: Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance Author: Lee, Tae-Kyu, Chen, Zhiqiang, Guirguis, Cherif, Akinade, Kola Year: 2017 The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases with higher electric power condition, which brings the component into an elevated temperature environment, thus introducing another consideration factor for mechanical stability of interconnection joints. Since most of the shock performance data available were produced at room temperature, the effect of elevated temperature is of interest to ensure the reliability of the device in a mechanical shock environment. To achieve a stablea interconnect pound in a dynamic shock environment, the interconnections must tolerate mechanical strain, which is induced by the shock wave input and reaches the particular component interconnect joint. In this study, large body size (52.5 x 52.5 mm(2)) FCBGA components assembled on 2.4-mm-thick boards were tested with various isothermal pre-conditions and testing conditions. With a heating element embedded in the test board, a test temperature range from room temperature to 100A degrees C was established. The effects of elevated temperature on mechanical shock performance were investigated. Failure and degradation mechanisms are identified and discussed based on the microstructure evolution and grain structure transformations. Close

• 3. [Article] Impact of Soil Moisture–Atmosphere Interactions on Surface Temperature Distribution

  Understanding how different physical processes can shape the probability distribution function (PDF) of surface temperature, in particular the tails of the distribution, is essential for the attribution ...

  Citation × Citation Citation Abstract Copy Title: Impact of Soil Moisture–Atmosphere Interactions on Surface Temperature Distribution Author: Berg, Alexis, Lintner, Benjamin R., Findell, Kirsten L., Malyshev, Sergey, Loikith, Paul C., Gentine, Pierre Year: 2014 Understanding how different physical processes can shape the probability distribution function (PDF) of surface temperature, in particular the tails of the distribution, is essential for the attribution and projection of future extreme temperature events. In this study, the contribution of soil moisture–atmosphere interactions to surface temperature PDFs is investigated. Soil moisture represents a key variable in the coupling of the land and atmosphere, since it controls the partitioning of available energy between sensible and latent heat flux at the surface. Consequently, soil moisture variability driven by the atmosphere may feed back onto the near-surface climate—in particular, temperature. In this study, two simulations of the current-generation Geophysical Fluid Dynamics Laboratory (GFDL) Earth System Model, with and without interactive soil moisture, are analyzed in order to assess how soil moisture dynamics impact the simulated climate. Comparison of these simulations shows that soil moisture dynamics enhance both temperature mean and variance over regional ‘‘hotspots’’ of land–atmosphere coupling.Moreover, higher-order distribution moments, such as skewness and kurtosis, are also significantly impacted, suggesting an asymmetric impact on the positive and negative extremes of the temperature PDF. Such changes are interpreted in the context of altered distributions of the surface turbulent and radiative fluxes. That the moments of the temperature distribution may respond differentially to soil moisture dynamics underscores the importance of analyzing moments beyond the mean and variance to characterize fully the interplay of soil moisture and near-surface temperature. In addition, it is shown that soil moisture dynamics impacts daily temperature variability at different time scales over different regions in the model. Title: Impact of Soil Moisture–Atmosphere Interactions on Surface Temperature Distribution Author: Berg, Alexis, Lintner, Benjamin R., Findell, Kirsten L., Malyshev, Sergey, Loikith, Paul C., Gentine, Pierre Year: 2014 Understanding how different physical processes can shape the probability distribution function (PDF) of surface temperature, in particular the tails of the distribution, is essential for the attribution and projection of future extreme temperature events. In this study, the contribution of soil moisture–atmosphere interactions to surface temperature PDFs is investigated. Soil moisture represents a key variable in the coupling of the land and atmosphere, since it controls the partitioning of available energy between sensible and latent heat flux at the surface. Consequently, soil moisture variability driven by the atmosphere may feed back onto the near-surface climate—in particular, temperature. In this study, two simulations of the current-generation Geophysical Fluid Dynamics Laboratory (GFDL) Earth System Model, with and without interactive soil moisture, are analyzed in order to assess how soil moisture dynamics impact the simulated climate. Comparison of these simulations shows that soil moisture dynamics enhance both temperature mean and variance over regional ‘‘hotspots’’ of land–atmosphere coupling.Moreover, higher-order distribution moments, such as skewness and kurtosis, are also significantly impacted, suggesting an asymmetric impact on the positive and negative extremes of the temperature PDF. Such changes are interpreted in the context of altered distributions of the surface turbulent and radiative fluxes. That the moments of the temperature distribution may respond differentially to soil moisture dynamics underscores the importance of analyzing moments beyond the mean and variance to characterize fully the interplay of soil moisture and near-surface temperature. In addition, it is shown that soil moisture dynamics impacts daily temperature variability at different time scales over different regions in the model. Close

• 4. [Article] The Influence of Recurrent Modes of Climate Variability on the Occurrence of Winter and Summer Extreme Temperatures over North America

  The influence of the Pacific–North American (PNA) pattern, the northern annular mode (NAM), and the El Ni~no–Southern Oscillation (ENSO) on extreme temperature days and months over North America is examined. ...

  Citation × Citation Citation Abstract Copy Title: The Influence of Recurrent Modes of Climate Variability on the Occurrence of Winter and Summer Extreme Temperatures over North America Author: Loikith, Paul C., Broccoli, Anthony J. Year: 2014 The influence of the Pacific–North American (PNA) pattern, the northern annular mode (NAM), and the El Ni~no–Southern Oscillation (ENSO) on extreme temperature days and months over North America is examined. Associations between extreme temperature days and months are strongest with the PNA and NAM andweaker for ENSO. In general, the associationwith extremes tends to be stronger onmonthly than daily time scales and for winter as compared to summer. Extreme temperatures are associated with the PNAandNAMin the vicinity of the centers of action of these circulation patterns; however, many extremes also occur on days when the amplitude and polarity of these patterns do not favor their occurrence. In winter, synoptic-scale, transient weather disturbances are important drivers of extreme temperature days; however, many of these smaller-scale events are concurrent with amplified PNA or NAMpatterns. Associations are weaker in summer when other physicalmechanisms affecting the surface energy balance, such as anomalous soilmoisture content, also influence the occurrence of extreme temperatures. Title: The Influence of Recurrent Modes of Climate Variability on the Occurrence of Winter and Summer Extreme Temperatures over North America Author: Loikith, Paul C., Broccoli, Anthony J. Year: 2014 The influence of the Pacific–North American (PNA) pattern, the northern annular mode (NAM), and the El Ni~no–Southern Oscillation (ENSO) on extreme temperature days and months over North America is examined. Associations between extreme temperature days and months are strongest with the PNA and NAM andweaker for ENSO. In general, the associationwith extremes tends to be stronger onmonthly than daily time scales and for winter as compared to summer. Extreme temperatures are associated with the PNAandNAMin the vicinity of the centers of action of these circulation patterns; however, many extremes also occur on days when the amplitude and polarity of these patterns do not favor their occurrence. In winter, synoptic-scale, transient weather disturbances are important drivers of extreme temperature days; however, many of these smaller-scale events are concurrent with amplified PNA or NAMpatterns. Associations are weaker in summer when other physicalmechanisms affecting the surface energy balance, such as anomalous soilmoisture content, also influence the occurrence of extreme temperatures. Close

• 5. [Article] Prospectus for Future Research: Temperature Effects on Green Macroalgae

  Research on temperature change has received attention from scientists. Not only has temperature change attracted scientists who study the Earth’s weather and climate, but also those who study plants and ...

  Citation × Citation Citation Abstract Copy Title: Prospectus for Future Research: Temperature Effects on Green Macroalgae Author: Gonzalez Pelayo, Ana Year: 2016 Research on temperature change has received attention from scientists. Not only has temperature change attracted scientists who study the Earth’s weather and climate, but also those who study plants and animals on land and in oceans. The research being conducted looks at how these temperature changes affect the anatomy and physiology of organisms, but other research also studies how terrestrial and aquatic ecosystems have changed and the types of responses that have occurred as a result. For many years, research in terrestrial ecosystems has dominated research in aquatic ecosystems. Limited research has been conducted in aquatic ecosystems involving green macroalgae, which are primary producers and an essential part of these ecosystems. Within the last fifteen years, research regarding the effects of temperature change on green macroalgae has shown that temperature affects photosynthesis and biochemistry. Overall, photosynthesis is almost completely inhibited after sufficient exposure due to damage in Photosystem II. There is also a substantial change in the production of chemical molecules known as reactive oxygen species that caused physical damage to the algal cells as well as a change in structure for proteins that is essential for function. I reviewed the literature within the past fifteen years, regarding the effects of temperature on a variety of green macroalgae species. The results indicated that after sufficient exposure, the photosynthetic rate of macroalgae is reduced significantly and that the change in chemistry lead to alterations in the physiology of green macroalgae. In this thesis, I propose two possible directions for algae research that involves genetic sequencing of a model species to identify a possible temperature tolerance gene, as well as the potential use of green macroalgae in photobioreactors as a source of renewable energy. Title: Prospectus for Future Research: Temperature Effects on Green Macroalgae Author: Gonzalez Pelayo, Ana Year: 2016 Research on temperature change has received attention from scientists. Not only has temperature change attracted scientists who study the Earth’s weather and climate, but also those who study plants and animals on land and in oceans. The research being conducted looks at how these temperature changes affect the anatomy and physiology of organisms, but other research also studies how terrestrial and aquatic ecosystems have changed and the types of responses that have occurred as a result. For many years, research in terrestrial ecosystems has dominated research in aquatic ecosystems. Limited research has been conducted in aquatic ecosystems involving green macroalgae, which are primary producers and an essential part of these ecosystems. Within the last fifteen years, research regarding the effects of temperature change on green macroalgae has shown that temperature affects photosynthesis and biochemistry. Overall, photosynthesis is almost completely inhibited after sufficient exposure due to damage in Photosystem II. There is also a substantial change in the production of chemical molecules known as reactive oxygen species that caused physical damage to the algal cells as well as a change in structure for proteins that is essential for function. I reviewed the literature within the past fifteen years, regarding the effects of temperature on a variety of green macroalgae species. The results indicated that after sufficient exposure, the photosynthetic rate of macroalgae is reduced significantly and that the change in chemistry lead to alterations in the physiology of green macroalgae. In this thesis, I propose two possible directions for algae research that involves genetic sequencing of a model species to identify a possible temperature tolerance gene, as well as the potential use of green macroalgae in photobioreactors as a source of renewable energy. Close

• 6. [Article] Impact of an Elevated Temperature Environment on Sn-Ag-Cu Interconnect Board Level High-G Mechanical Shock Performance

  The mechanical stability of Sn-Ag-Cu interconnects with low and high silver content against mechanical shock at room and elevated temperatures was investigated. With a heating element-embedded printed ...

  Citation × Citation Citation Abstract Copy Title: Impact of an Elevated Temperature Environment on Sn-Ag-Cu Interconnect Board Level High-G Mechanical Shock Performance Author: Lee, Tae-Kyu, Chen, Zhiqiang, Baty, Greg, Bieler, Thomas R., Kim, Choong-Un Year: 2016 The mechanical stability of Sn-Ag-Cu interconnects with low and high silver content against mechanical shock at room and elevated temperatures was investigated. With a heating element-embedded printed circuit board design, a test temperature from room temperature to 80°C was established. High impact shock tests were applied to isothermally pre-conditioned ball-grid array interconnects. Under cyclic shock testing, degradation and improved shock performances were identified associated with test temperature variation and non-solder mask defined and solder-mask defined pad design configuration differences. Different crack propagation paths were observed, induced by the effect of the elevated temperature test conditions and isothermal aging pre-conditions. Title: Impact of an Elevated Temperature Environment on Sn-Ag-Cu Interconnect Board Level High-G Mechanical Shock Performance Author: Lee, Tae-Kyu, Chen, Zhiqiang, Baty, Greg, Bieler, Thomas R., Kim, Choong-Un Year: 2016 The mechanical stability of Sn-Ag-Cu interconnects with low and high silver content against mechanical shock at room and elevated temperatures was investigated. With a heating element-embedded printed circuit board design, a test temperature from room temperature to 80°C was established. High impact shock tests were applied to isothermally pre-conditioned ball-grid array interconnects. Under cyclic shock testing, degradation and improved shock performances were identified associated with test temperature variation and non-solder mask defined and solder-mask defined pad design configuration differences. Different crack propagation paths were observed, induced by the effect of the elevated temperature test conditions and isothermal aging pre-conditions. Close

• 7. [Article] Short-tailed temperature distributions over North America and Implications for Future Changes in Extremes

  Some regions of North America exhibit nonnormal temperature distributions. Shorter-than-Gaussian warm tails are a special subset of these cases, with potentially meaningful implications for future changes ...

  Citation × Citation Citation Abstract Copy Title: Short-tailed temperature distributions over North America and Implications for Future Changes in Extremes Author: Loikith, Paul C., Neelin, J. David Year: 2015 Some regions of North America exhibit nonnormal temperature distributions. Shorter-than-Gaussian warm tails are a special subset of these cases, with potentially meaningful implications for future changes in extreme warm temperatures under anthropogenic global warming. Locations exhibiting shorter-than-Gaussian warm tails would experience a greater increase in extreme warm temperature exceedances than a location with a Gaussian or long warm-side tail under a simple uniform warm shift in the distribution. Here we identify regions exhibiting such behavior over North America and demonstrate the effect of a simple warm shift on changes in extreme warm temperature exceedances. Some locations exceed the 95th percentile of the original distribution by greater than 40% of the time after this uniform shift. While the manner in which distributions change under global warming may be more complex than a simple shift, these results provide an observational baseline for climate model evaluation. Title: Short-tailed temperature distributions over North America and Implications for Future Changes in Extremes Author: Loikith, Paul C., Neelin, J. David Year: 2015 Some regions of North America exhibit nonnormal temperature distributions. Shorter-than-Gaussian warm tails are a special subset of these cases, with potentially meaningful implications for future changes in extreme warm temperatures under anthropogenic global warming. Locations exhibiting shorter-than-Gaussian warm tails would experience a greater increase in extreme warm temperature exceedances than a location with a Gaussian or long warm-side tail under a simple uniform warm shift in the distribution. Here we identify regions exhibiting such behavior over North America and demonstrate the effect of a simple warm shift on changes in extreme warm temperature exceedances. Some locations exceed the 95th percentile of the original distribution by greater than 40% of the time after this uniform shift. While the manner in which distributions change under global warming may be more complex than a simple shift, these results provide an observational baseline for climate model evaluation. Close

• 8. [Article] Temperature Dependent Transcription Initiation in Archaea: Interplay between Transcription Factor B and Promoter Sequence

  In Pyrococcus furiosus (Pfu), a hyperthermophile archaeon, two transcription factor Bs, TFB1 and TFB2 are encoded in the genomic DNA. TFB1 is the primary TFB in Pfu, and is homologous to transcription ...

  Citation × Citation Citation Abstract Copy Title: Temperature Dependent Transcription Initiation in Archaea: Interplay between Transcription Factor B and Promoter Sequence Author: Wu, Ming-Hsiao Year: 2014 In Pyrococcus furiosus (Pfu), a hyperthermophile archaeon, two transcription factor Bs, TFB1 and TFB2 are encoded in the genomic DNA. TFB1 is the primary TFB in Pfu, and is homologous to transcription factor IIB (TFIIB) in eukaryotes. TFB2 is proposed to be a secondary TFB that is compared to TFB1, TFB2 lacks the conserved B-finger / B-reader / B-linker regions which assist RNA polymerase in transcription start site selection and promoter opening functions respectively. P. furiosus, like all Archaea, encodes a single transcription factor E (TFE), that is homologous to the N-terminus of transcription factor II E (TFIIE) α subunit in eukaryotes. TFE stabilizes the transcription bubble when present, although it is not required for in vitro transcription. In this study, in vitro transcription is used to reveal how TFB2 responds to different temperature (65 °C, 70 °C, 75 °C, 80 °C, and 85 °C) at promoters for three different kinds of gene: non-temperature responsive, heat-shock induced, and cold-shock induced in the absence or presence of TFE. The activity of transcription complexes formed by TFB2 is always lower than by TFB1 in all temperatures and promoters. However, with heat-shock gene promoters, the activity of transcription complexes formed by TFB2 increases more than those formed with TFB1 with increasing temperatures. The temperature-dependent activities of TFB1 and TFB2 are similar with the non-temperature responsive gene promoter. With the cold-shock gene promoter, the activity of transcription complexes formed by both TFB1 and TFB2 has the highest activity in lower temperatures. When TFE is present, the activity of transcription complexes formed by TFB2 is enhanced with heat-shock gene promoters particularly at lower temperatures, and makes TFB2 behave more similarly to TFB1. With the non-temperature responsive gene promoter, TFB2 still behaves similarly to TFB1 when TFE is present. However, with the cold-shock gene promoter, most of the activity of transcription complexes formed by TFB1 and TFB2 remain the same, but only the activity of TFB1 decreases at 75 °C. The results suggest that TFB2 may play a role in heat-shock response through its increased sensitivity to temperature, and that TFE can modulate this temperature response. Title: Temperature Dependent Transcription Initiation in Archaea: Interplay between Transcription Factor B and Promoter Sequence Author: Wu, Ming-Hsiao Year: 2014 In Pyrococcus furiosus (Pfu), a hyperthermophile archaeon, two transcription factor Bs, TFB1 and TFB2 are encoded in the genomic DNA. TFB1 is the primary TFB in Pfu, and is homologous to transcription factor IIB (TFIIB) in eukaryotes. TFB2 is proposed to be a secondary TFB that is compared to TFB1, TFB2 lacks the conserved B-finger / B-reader / B-linker regions which assist RNA polymerase in transcription start site selection and promoter opening functions respectively. P. furiosus, like all Archaea, encodes a single transcription factor E (TFE), that is homologous to the N-terminus of transcription factor II E (TFIIE) α subunit in eukaryotes. TFE stabilizes the transcription bubble when present, although it is not required for in vitro transcription. In this study, in vitro transcription is used to reveal how TFB2 responds to different temperature (65 °C, 70 °C, 75 °C, 80 °C, and 85 °C) at promoters for three different kinds of gene: non-temperature responsive, heat-shock induced, and cold-shock induced in the absence or presence of TFE. The activity of transcription complexes formed by TFB2 is always lower than by TFB1 in all temperatures and promoters. However, with heat-shock gene promoters, the activity of transcription complexes formed by TFB2 increases more than those formed with TFB1 with increasing temperatures. The temperature-dependent activities of TFB1 and TFB2 are similar with the non-temperature responsive gene promoter. With the cold-shock gene promoter, the activity of transcription complexes formed by both TFB1 and TFB2 has the highest activity in lower temperatures. When TFE is present, the activity of transcription complexes formed by TFB2 is enhanced with heat-shock gene promoters particularly at lower temperatures, and makes TFB2 behave more similarly to TFB1. With the non-temperature responsive gene promoter, TFB2 still behaves similarly to TFB1 when TFE is present. However, with the cold-shock gene promoter, most of the activity of transcription complexes formed by TFB1 and TFB2 remain the same, but only the activity of TFB1 decreases at 75 °C. The results suggest that TFB2 may play a role in heat-shock response through its increased sensitivity to temperature, and that TFE can modulate this temperature response. Close

• 9. [Article] Surface Temperature Probability Distributions in the NARCCAP Hindcast Experiment: Evaluation Methodology, Metrics, and Results

  Methodology is developed and applied to evaluate the characteristics of daily surface temperature distributions in a six-member regional climate model (RCM) hindcast experiment conducted as part of the ...

  Citation × Citation Citation Abstract Copy Title: Surface Temperature Probability Distributions in the NARCCAP Hindcast Experiment: Evaluation Methodology, Metrics, and Results Author: Loikith, Paul C., Waliser, Duane E., Lee, Huikyo, Kim, Jinwon, Neelin, J. David, Lintner, Benjamin R., McGinnis, Seth, Mattmann, Chris A., Mears, Linda O. Year: 2015 Methodology is developed and applied to evaluate the characteristics of daily surface temperature distributions in a six-member regional climate model (RCM) hindcast experiment conducted as part of the North American Regional Climate Change Assessment Program (NARCCAP). A surface temperature dataset combining gridded station observations and reanalysis is employed as the primary reference. Temperature biases are documented across the distribution, focusing on the median and tails. Temperature variance is generally higher in the RCMs than reference, while skewness is reasonably simulated in winter over the entire domain and over the western United States and Canada in summer. Substantial differences in skewness exist over the southern and eastern portions of the domain in summer. Four examples with observed long-tailed probability distribution functions (PDFs) are selected for model comparison. Long cold tails in the winter are simulated with high fidelity for Seattle, Washington, and Chicago, Illinois. In summer, theRCMs are unable to capture the distribution width and long warm tails for the coastal location of Los Angeles, California, while long cold tails are poorly realized for Houston, Texas. The evaluation results are repeated using two additional reanalysis products adjusted by station observations and two standard reanalysis products to assess the impact of observational uncertainty. Results are robust when compared with those obtained using the adjusted reanalysis products as reference, while larger uncertainties are introduced when standard reanalysis is employed as reference. Model biases identified in this work will allow for further investigation into associated mechanisms and implications for future simulations of temperature extremes. Title: Surface Temperature Probability Distributions in the NARCCAP Hindcast Experiment: Evaluation Methodology, Metrics, and Results Author: Loikith, Paul C., Waliser, Duane E., Lee, Huikyo, Kim, Jinwon, Neelin, J. David, Lintner, Benjamin R., McGinnis, Seth, Mattmann, Chris A., Mears, Linda O. Year: 2015 Methodology is developed and applied to evaluate the characteristics of daily surface temperature distributions in a six-member regional climate model (RCM) hindcast experiment conducted as part of the North American Regional Climate Change Assessment Program (NARCCAP). A surface temperature dataset combining gridded station observations and reanalysis is employed as the primary reference. Temperature biases are documented across the distribution, focusing on the median and tails. Temperature variance is generally higher in the RCMs than reference, while skewness is reasonably simulated in winter over the entire domain and over the western United States and Canada in summer. Substantial differences in skewness exist over the southern and eastern portions of the domain in summer. Four examples with observed long-tailed probability distribution functions (PDFs) are selected for model comparison. Long cold tails in the winter are simulated with high fidelity for Seattle, Washington, and Chicago, Illinois. In summer, theRCMs are unable to capture the distribution width and long warm tails for the coastal location of Los Angeles, California, while long cold tails are poorly realized for Houston, Texas. The evaluation results are repeated using two additional reanalysis products adjusted by station observations and two standard reanalysis products to assess the impact of observational uncertainty. Results are robust when compared with those obtained using the adjusted reanalysis products as reference, while larger uncertainties are introduced when standard reanalysis is employed as reference. Model biases identified in this work will allow for further investigation into associated mechanisms and implications for future simulations of temperature extremes. Close

• 10. [Article] Use of Distance Weighted Metrics to Investigate Landscape-Stream Temperature Relationships Across Different Temporal Scales

  Stream ecosystems have experienced significant negative impacts from land use, resource exploitation, and urban development. Statistical models allow researchers to explore the relationships between these ...

  Citation × Citation Citation Abstract Copy Title: Use of Distance Weighted Metrics to Investigate Landscape-Stream Temperature Relationships Across Different Temporal Scales Author: Watson, Eric Craig Year: 2016 Stream ecosystems have experienced significant negative impacts from land use, resource exploitation, and urban development. Statistical models allow researchers to explore the relationships between these landscape variables and stream conditions. Weighting the relevant landscape variables based on hydrologically defined distances offers a potential method of increasing the predictive capacity of statistical models. Using observations from three grouped watersheds in the Portland Metro Area (n=66), I have explored the use of three different weighting schemes against the standard method of taking an areal average. These four different model groups were applied to four stream temperature metrics: mean seven-day moving average maximum daily temperature (Mean7dTmax), number of days exceeding 17.8 °C (Tmax7d>17.8), mean daily range in stream temperature (Range_DTR), and the coefficient of variation in maximum daily temperature (CV_Tmax). These metrics were quantified for the 2011 dry season. The strength of these model groups were also examined at a monthly basis for each of the four months within the dry season. The results demonstrate mixed effectiveness of the weighting schemes, dependent on both the stream temperature metric being predicted as well as the time scale under investigation. Models for Mean7dTmax showed no benefit from the inclusion of distance weighted metrics, while models for Range_DTR consistently improved using distance weighted explanatory variables. Trends in the models for 7dTmax>17.8 and CV_Tmax varied based on temporal scale. Additionally, all model groups demonstrated greater explanatory power in early summer months than in late summer months. Title: Use of Distance Weighted Metrics to Investigate Landscape-Stream Temperature Relationships Across Different Temporal Scales Author: Watson, Eric Craig Year: 2016 Stream ecosystems have experienced significant negative impacts from land use, resource exploitation, and urban development. Statistical models allow researchers to explore the relationships between these landscape variables and stream conditions. Weighting the relevant landscape variables based on hydrologically defined distances offers a potential method of increasing the predictive capacity of statistical models. Using observations from three grouped watersheds in the Portland Metro Area (n=66), I have explored the use of three different weighting schemes against the standard method of taking an areal average. These four different model groups were applied to four stream temperature metrics: mean seven-day moving average maximum daily temperature (Mean7dTmax), number of days exceeding 17.8 °C (Tmax7d>17.8), mean daily range in stream temperature (Range_DTR), and the coefficient of variation in maximum daily temperature (CV_Tmax). These metrics were quantified for the 2011 dry season. The strength of these model groups were also examined at a monthly basis for each of the four months within the dry season. The results demonstrate mixed effectiveness of the weighting schemes, dependent on both the stream temperature metric being predicted as well as the time scale under investigation. Models for Mean7dTmax showed no benefit from the inclusion of distance weighted metrics, while models for Range_DTR consistently improved using distance weighted explanatory variables. Trends in the models for 7dTmax>17.8 and CV_Tmax varied based on temporal scale. Additionally, all model groups demonstrated greater explanatory power in early summer months than in late summer months. Close

• 11. [Article] Determining Initial Firing Temperatures of Thule Era (1000-250 ya) Pottery from Two Northwest Alaskan Archaeological Sites

  This research was conducted to investigate the initial firing temperatures (IFT) of pottery from two archaeological sites in Northwest Alaska. Arctic ceramics are consistently described as low-fired technology ...

  Citation × Citation Citation Abstract Copy Title: Determining Initial Firing Temperatures of Thule Era (1000-250 ya) Pottery from Two Northwest Alaskan Archaeological Sites Author: Duelks, Jonathan Year: 2015 This research was conducted to investigate the initial firing temperatures (IFT) of pottery from two archaeological sites in Northwest Alaska. Arctic ceramics are consistently described as low-fired technology in archaeological and ethnographic literature. However, regional and temporal variation in the quality and hardness of arctic ceramics suggests variation in firing temperatures. To describe all Arctic pottery as low-fired ignores variation in firing temperatures and ultimately in the production process. Sherds from two archaeological locales, the Cape Krusenstern site complex and the Ahteut village site, were selected to represent sites with differential access to fuel resources. IFT’s were estimated by measuring color change in a stepwise refiring experiment. Preliminary results indicate that a majority of sherds from Cape Krusenstern had lower initial firing temperatures than did sherds from Ahteut. Additionally, this experiment indicates that (1) a majority of the sherds contained residual organic content, (2) shows the effects of the presence of organic content on a refiring experiment, and (3) confirms that vessels from these two sites were originally fired under reducing atmospheres. These results do provide a better understanding of the production process of arctic ceramics. The difference between the initial firing atmosphere and the refiring atmosphere, as well as the presence of organic content, may be masking the true indications of initial firing temperatures. Because of these confounding factors additional research, including alternative methods of estimating initial firing temperatures, are necessary. Beyond reconstructing the production process of Northwest Alaskan ceramics, understanding initial firing temperatures provides important information regarding environmental constraints on the ceramic production process and the methods precontact potters used to overcome them. This work also adds to our understanding of fuel use and management. Title: Determining Initial Firing Temperatures of Thule Era (1000-250 ya) Pottery from Two Northwest Alaskan Archaeological Sites Author: Duelks, Jonathan Year: 2015 This research was conducted to investigate the initial firing temperatures (IFT) of pottery from two archaeological sites in Northwest Alaska. Arctic ceramics are consistently described as low-fired technology in archaeological and ethnographic literature. However, regional and temporal variation in the quality and hardness of arctic ceramics suggests variation in firing temperatures. To describe all Arctic pottery as low-fired ignores variation in firing temperatures and ultimately in the production process. Sherds from two archaeological locales, the Cape Krusenstern site complex and the Ahteut village site, were selected to represent sites with differential access to fuel resources. IFT’s were estimated by measuring color change in a stepwise refiring experiment. Preliminary results indicate that a majority of sherds from Cape Krusenstern had lower initial firing temperatures than did sherds from Ahteut. Additionally, this experiment indicates that (1) a majority of the sherds contained residual organic content, (2) shows the effects of the presence of organic content on a refiring experiment, and (3) confirms that vessels from these two sites were originally fired under reducing atmospheres. These results do provide a better understanding of the production process of arctic ceramics. The difference between the initial firing atmosphere and the refiring atmosphere, as well as the presence of organic content, may be masking the true indications of initial firing temperatures. Because of these confounding factors additional research, including alternative methods of estimating initial firing temperatures, are necessary. Beyond reconstructing the production process of Northwest Alaskan ceramics, understanding initial firing temperatures provides important information regarding environmental constraints on the ceramic production process and the methods precontact potters used to overcome them. This work also adds to our understanding of fuel use and management. Close

• 12. [Article] Hydrodynamic and Water Quality Modeling of the Chehalis River Using CE-QUAL-W2

  The Chehalis River Basin is located in the southwest region of Washington State, originating in the Olympic Mountains and flowing to Grays Harbor and the Pacific Ocean. The Chehalis River is over 125 miles, ...

  Citation × Citation Citation Abstract Copy Title: Hydrodynamic and Water Quality Modeling of the Chehalis River Using CE-QUAL-W2 Author: Van Glubt, Sarah Year: 2017 The Chehalis River Basin is located in the southwest region of Washington State, originating in the Olympic Mountains and flowing to Grays Harbor and the Pacific Ocean. The Chehalis River is over 125 miles, exists within five counties, and flows through agricultural, residential, industrial, and forest land areas. Four major rivers discharge to the Chehalis River, as well as many smaller creeks, five wastewater treatment plants, and groundwater flows. Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia, with severe consequences for property, safety and transportation. As a result, construction of a flood-control dam in the upper basin has been proposed. One major concern of constructing a dam is the potentially severe impacts to fish health and habitat. The Chehalis River has routinely violated water quality standards for primarily temperature and dissolved oxygen, and has had multiple water quality and Total Maximum Daily Load studies beginning in 1990. CE-QUAL-W2, a two-dimensional (longitudinal and vertical) hydrodynamic and water quality model, was used to simulate the Chehalis River, including free flowing river stretches and stratified (in summer) lake-like stretches. The goals of this research were to assess the flood retention structure's impacts to water quality, as well as river responses to potential climate change scenarios. In order to use the model to achieve these goals, calibration to field data for flow, temperature, and water quality constituents was performed. This involved developing meteorological data, riparian shading data, and flow, temperature, water quality records for all tributaries during the calibration period of January 1, 2013 to December 31, 2014. System cross-sectional geometry data were also required for the model grid. Because of the short travel time in the river, the model was sensitive to boundary condition data, wind speed, bathymetry, nutrient kinetics, and algae, epiphyton, and zooplankton kinetics. Future conditions showed predictions of warmer water temperatures and slight changes to water quality conditions on the river. As fish in the area prefer cooler water temperatures, this could pose a threat to fish health and habitat. Flood retention structures also showed impacts to river temperature and water quality. Structures with the purpose of flood retention only (only operating during times of flooding) gave model predictions for daily maximum temperature higher than structures that employed flood retention and flow augmentation (operating during all times of the year). This suggested the management of flow passage or retention by the dam is important for water quality on the river. As this research continues improvements will be made, particularly to temperature and water quality constituents. Additional data for the system would be beneficial to this process. Model predictions of temperature were sensitive to meteorological data, including cloud cover, which were largely estimated based on solar radiation. Additional meteorological data throughout the basin would be useful to temperature results. Temperature results were also sensitive to the model bathymetry, and additional investigations into segments widths and water depths may improve temperature predictions. Water quality constituent data were largely lacking for the system. Many estimation techniques and approximations were used for input water quality constituents for the model upstream boundary and tributaries when little or no data were available, introducing uncertainty to the model. It was not possible to calibrate pH to field data because alkalinity data were essentially unavailable. However, other constituents had good agreement between model predictions and field data, including dissolved oxygen, nitrates, total phosphorus, and total suspended solids. Title: Hydrodynamic and Water Quality Modeling of the Chehalis River Using CE-QUAL-W2 Author: Van Glubt, Sarah Year: 2017 The Chehalis River Basin is located in the southwest region of Washington State, originating in the Olympic Mountains and flowing to Grays Harbor and the Pacific Ocean. The Chehalis River is over 125 miles, exists within five counties, and flows through agricultural, residential, industrial, and forest land areas. Four major rivers discharge to the Chehalis River, as well as many smaller creeks, five wastewater treatment plants, and groundwater flows. Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia, with severe consequences for property, safety and transportation. As a result, construction of a flood-control dam in the upper basin has been proposed. One major concern of constructing a dam is the potentially severe impacts to fish health and habitat. The Chehalis River has routinely violated water quality standards for primarily temperature and dissolved oxygen, and has had multiple water quality and Total Maximum Daily Load studies beginning in 1990. CE-QUAL-W2, a two-dimensional (longitudinal and vertical) hydrodynamic and water quality model, was used to simulate the Chehalis River, including free flowing river stretches and stratified (in summer) lake-like stretches. The goals of this research were to assess the flood retention structure's impacts to water quality, as well as river responses to potential climate change scenarios. In order to use the model to achieve these goals, calibration to field data for flow, temperature, and water quality constituents was performed. This involved developing meteorological data, riparian shading data, and flow, temperature, water quality records for all tributaries during the calibration period of January 1, 2013 to December 31, 2014. System cross-sectional geometry data were also required for the model grid. Because of the short travel time in the river, the model was sensitive to boundary condition data, wind speed, bathymetry, nutrient kinetics, and algae, epiphyton, and zooplankton kinetics. Future conditions showed predictions of warmer water temperatures and slight changes to water quality conditions on the river. As fish in the area prefer cooler water temperatures, this could pose a threat to fish health and habitat. Flood retention structures also showed impacts to river temperature and water quality. Structures with the purpose of flood retention only (only operating during times of flooding) gave model predictions for daily maximum temperature higher than structures that employed flood retention and flow augmentation (operating during all times of the year). This suggested the management of flow passage or retention by the dam is important for water quality on the river. As this research continues improvements will be made, particularly to temperature and water quality constituents. Additional data for the system would be beneficial to this process. Model predictions of temperature were sensitive to meteorological data, including cloud cover, which were largely estimated based on solar radiation. Additional meteorological data throughout the basin would be useful to temperature results. Temperature results were also sensitive to the model bathymetry, and additional investigations into segments widths and water depths may improve temperature predictions. Water quality constituent data were largely lacking for the system. Many estimation techniques and approximations were used for input water quality constituents for the model upstream boundary and tributaries when little or no data were available, introducing uncertainty to the model. It was not possible to calibrate pH to field data because alkalinity data were essentially unavailable. However, other constituents had good agreement between model predictions and field data, including dissolved oxygen, nitrates, total phosphorus, and total suspended solids. Close

• 13. [Article] Approximate Equations of State in Two-Temperature Plasma Mixtures

  Approximate thermodynamic state relations for multicomponent atomic and molecular gas mixtures are often constructed by artificially partitioning the mixture into its constituent materials and requiring ...

  Citation × Citation Citation Abstract Copy Title: Approximate Equations of State in Two-Temperature Plasma Mixtures Author: Ramshaw, John D., Cook, Andrew W. Year: 2014 Approximate thermodynamic state relations for multicomponent atomic and molecular gas mixtures are often constructed by artificially partitioning the mixture into its constituent materials and requiring the separated materials to be in temperature and pressure equilibrium. Iterative numerical algorithms have been employed to enforce this equilibration and compute the resulting approximate state relations in single-temperature mixtures. In partially ionized gas mixtures, there is both theoretical and empirical evidence that equilibrating the chemical potentials, number densities, or partial pressures of the free electrons is likely to produce more accurate results than equilibrating the total pressures. Moreover, in many situations of practical interest the free electrons and heavy particles have different temperatures. In this paper, we present a generalized algorithm for equilibrating the heavy-particle and electron temperaturesand a third user-specified independent thermodynamic variable in a two-temperature plasmamixture. Test calculations based on the equilibration of total pressure vs. electron pressure are presented for three different mixtures. Title: Approximate Equations of State in Two-Temperature Plasma Mixtures Author: Ramshaw, John D., Cook, Andrew W. Year: 2014 Approximate thermodynamic state relations for multicomponent atomic and molecular gas mixtures are often constructed by artificially partitioning the mixture into its constituent materials and requiring the separated materials to be in temperature and pressure equilibrium. Iterative numerical algorithms have been employed to enforce this equilibration and compute the resulting approximate state relations in single-temperature mixtures. In partially ionized gas mixtures, there is both theoretical and empirical evidence that equilibrating the chemical potentials, number densities, or partial pressures of the free electrons is likely to produce more accurate results than equilibrating the total pressures. Moreover, in many situations of practical interest the free electrons and heavy particles have different temperatures. In this paper, we present a generalized algorithm for equilibrating the heavy-particle and electron temperaturesand a third user-specified independent thermodynamic variable in a two-temperature plasmamixture. Test calculations based on the equilibration of total pressure vs. electron pressure are presented for three different mixtures. Close

• 14. [Article] TEMPERATURE CHANGES IN HUMAN SKELETAL MUSCLE DURING SINGLE LEG DYNAMIC KNEE EXTENSION EXERCISE

  49 pages. A thesis presented to the Department of Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Arts, Summer ...

  Citation × Citation Citation Abstract Copy Title: TEMPERATURE CHANGES IN HUMAN SKELETAL MUSCLE DURING SINGLE LEG DYNAMIC KNEE EXTENSION EXERCISE Author: Peck, Mairin Year: 2016, 2015 49 pages. A thesis presented to the Department of Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Arts, Summer 2015. Title: TEMPERATURE CHANGES IN HUMAN SKELETAL MUSCLE DURING SINGLE LEG DYNAMIC KNEE EXTENSION EXERCISE Author: Peck, Mairin Year: 2016, 2015 49 pages. A thesis presented to the Department of Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Arts, Summer 2015. Close

• 15. [Article] Towards p-Type Conductivity in SnO2Nanocrystals through Li Doping and Its Applications in Porous Diodes for Room Temperature Chlorine Gas Detection

  This work examined electrical transport properties and Li doping in SnO2synthesized by the sol–gel method. Solid-state 7Li-NMR line shapes revealed that Li ions occupy two distinct sites with differing ...

  Citation × Citation Citation Abstract Copy Title: Towards p-Type Conductivity in SnO2Nanocrystals through Li Doping and Its Applications in Porous Diodes for Room Temperature Chlorine Gas Detection Author: Chaparadza, Allen, Rananavare, Shankar Year: 2016 This work examined electrical transport properties and Li doping in SnO2synthesized by the sol–gel method. Solid-state 7Li-NMR line shapes revealed that Li ions occupy two distinct sites with differing dynamic mobilities. The chemical exchange rate between the two sites is, however, too slow for detection on the NMR timescale. Compressed nanoparticulate films of this doped semiconductor exhibited a positive Seebeck coefficient implying a p-type conductivity. A variable-temperature direct current conductivity, over a 25–350 °C temperature range, followed an Efros–Shklovskii variable range hopping (ES-VRH) conduction mechanism (ln(ρ) versus T−1/2) at temperatures below 100 °C with a crossover to 2D Mott variable range hopping (M-VRH) (ln(ρ) versus T−1/3) conduction at temperatures above 250 °C. In a transition region between these two limiting behaviors, direct current resistivity exhibited an anomalous temperature-independent plateau. We suggest that its origin may lie in a carrier inversion phenomenon wherein the majority carriers switch from holes to electrons due to Li ion expulsion from the crystalline core and creation of oxygen vacancies generated by loss of oxygen at elevated temperatures. Using a compression technique, porous diodes consisting of n-type (antimony doped SnO2) and the p-type (lithium-doped) nano-particulate films were prepared. Typical current-voltage curves of such devices resembled the behavior of a typical diode but for one key difference; owing to the porosity of the film, areas near the p-n interface and the p- and n-regions are accessible to gaseous analytes. This access is not possible in conventional diodes fabricated through contemporary planar technology. The gas sensing properties of the diodes were investigated by using Cl2, Br2, HCl, NO, NO2, CHCl3, NH3 and H2. Of all the gases tested, the sensor had very good sensitivity to Cl2 and had a response of 80 at 400 ppb of Cl2. The response time of the sensor was ~30 s at room temperature but the recovery time was temperature dependent. At room temperature the recovery time was 80s after 400 ppb chlorine exposure. The sensors were also found to recover quickly (~ 30 s) when the junctions were biased. Reverse biasing the diode provides a controllable band-bending at a p-n junction that could influence the electron-transfer rates from the adsorbates which create intra-band localized states. As a result reverse biasing can provide a means of desorbing the analyzed species. This approach eliminates the requirement to remove adsorbates by elevating the sensor temperature and hence improves on the energy efficiency of these types of sensors. Title: Towards p-Type Conductivity in SnO2Nanocrystals through Li Doping and Its Applications in Porous Diodes for Room Temperature Chlorine Gas Detection Author: Chaparadza, Allen, Rananavare, Shankar Year: 2016 This work examined electrical transport properties and Li doping in SnO2synthesized by the sol–gel method. Solid-state 7Li-NMR line shapes revealed that Li ions occupy two distinct sites with differing dynamic mobilities. The chemical exchange rate between the two sites is, however, too slow for detection on the NMR timescale. Compressed nanoparticulate films of this doped semiconductor exhibited a positive Seebeck coefficient implying a p-type conductivity. A variable-temperature direct current conductivity, over a 25–350 °C temperature range, followed an Efros–Shklovskii variable range hopping (ES-VRH) conduction mechanism (ln(ρ) versus T−1/2) at temperatures below 100 °C with a crossover to 2D Mott variable range hopping (M-VRH) (ln(ρ) versus T−1/3) conduction at temperatures above 250 °C. In a transition region between these two limiting behaviors, direct current resistivity exhibited an anomalous temperature-independent plateau. We suggest that its origin may lie in a carrier inversion phenomenon wherein the majority carriers switch from holes to electrons due to Li ion expulsion from the crystalline core and creation of oxygen vacancies generated by loss of oxygen at elevated temperatures. Using a compression technique, porous diodes consisting of n-type (antimony doped SnO2) and the p-type (lithium-doped) nano-particulate films were prepared. Typical current-voltage curves of such devices resembled the behavior of a typical diode but for one key difference; owing to the porosity of the film, areas near the p-n interface and the p- and n-regions are accessible to gaseous analytes. This access is not possible in conventional diodes fabricated through contemporary planar technology. The gas sensing properties of the diodes were investigated by using Cl2, Br2, HCl, NO, NO2, CHCl3, NH3 and H2. Of all the gases tested, the sensor had very good sensitivity to Cl2 and had a response of 80 at 400 ppb of Cl2. The response time of the sensor was ~30 s at room temperature but the recovery time was temperature dependent. At room temperature the recovery time was 80s after 400 ppb chlorine exposure. The sensors were also found to recover quickly (~ 30 s) when the junctions were biased. Reverse biasing the diode provides a controllable band-bending at a p-n junction that could influence the electron-transfer rates from the adsorbates which create intra-band localized states. As a result reverse biasing can provide a means of desorbing the analyzed species. This approach eliminates the requirement to remove adsorbates by elevating the sensor temperature and hence improves on the energy efficiency of these types of sensors. Close

• 16. [Article] Daytime Variation of Urban Heat Islands: The Case Study of Doha, Qatar

  Recent evidence suggests that urban forms and materials can help to mediate temporal variation of microclimates and that landscape modifications can potentially reduce temperatures and increase accessibility ...

  Citation × Citation Citation Abstract Copy Title: Daytime Variation of Urban Heat Islands: The Case Study of Doha, Qatar Author: Makido, Yasuyo, Shandas, Vivek, Ferwati, Salim, Sailor, David J. Year: 2016 Recent evidence suggests that urban forms and materials can help to mediate temporal variation of microclimates and that landscape modifications can potentially reduce temperatures and increase accessibility to outdoor environments. To understand the relationship between urban form and temperature moderation, we examined the spatial and temporal variation of air temperature throughout one desert city—Doha, Qatar—by conducting vehicle traverses using highly resolved temperature and GPS data logs to determine spatial differences in summertime air temperatures. To help explain near-surface air temperatures using land cover variables, we employed three statistical approaches: Ordinary Least Squares (OLS), Regression Tree Analysis (RTA), and Random Forest (RF). We validated the predictions of the statistical models by computing the Root Mean Square Error (RMSE) and discovered that temporal variations in urban heat are mediated by different factors throughout the day. The average RMSE for OLS, RTA and RF is 1.25, 0.96, and 0.65 (in Celsius), respectively, suggesting that the RF is the best model for predicting near-surface air temperatures at this study site. We conclude by recommending the features of the landscape that have the greatest potential for reducing extreme heat in arid climates. Title: Daytime Variation of Urban Heat Islands: The Case Study of Doha, Qatar Author: Makido, Yasuyo, Shandas, Vivek, Ferwati, Salim, Sailor, David J. Year: 2016 Recent evidence suggests that urban forms and materials can help to mediate temporal variation of microclimates and that landscape modifications can potentially reduce temperatures and increase accessibility to outdoor environments. To understand the relationship between urban form and temperature moderation, we examined the spatial and temporal variation of air temperature throughout one desert city—Doha, Qatar—by conducting vehicle traverses using highly resolved temperature and GPS data logs to determine spatial differences in summertime air temperatures. To help explain near-surface air temperatures using land cover variables, we employed three statistical approaches: Ordinary Least Squares (OLS), Regression Tree Analysis (RTA), and Random Forest (RF). We validated the predictions of the statistical models by computing the Root Mean Square Error (RMSE) and discovered that temporal variations in urban heat are mediated by different factors throughout the day. The average RMSE for OLS, RTA and RF is 1.25, 0.96, and 0.65 (in Celsius), respectively, suggesting that the RF is the best model for predicting near-surface air temperatures at this study site. We conclude by recommending the features of the landscape that have the greatest potential for reducing extreme heat in arid climates. Close

• 17. [Article] Estimation of Transient Temperature Distribution during Quenching, via a Parabolic Model

  A material-independent model to estimate the transient temperature distribution in a test probe quenched by immersion is presented in this study. This model is based on the assumption that, under one-dimensional ...

  Citation × Citation Citation Abstract Copy Title: Estimation of Transient Temperature Distribution during Quenching, via a Parabolic Model Author: Lozano, Diego E., Martinez-Solis, Gabriela, Mercado-Solis, Rafael David, Colás, Rafael, Totten, George E. Year: 2015 A material-independent model to estimate the transient temperature distribution in a test probe quenched by immersion is presented in this study. This model is based on the assumption that, under one-dimensional unsteady heat conduction, the radial temperature distribution at the end of an interval belongs to the equation of a parabola. The model was validated using AISI 304 stainless steel test probes (Φ8×40 mm and Φ12×60 mm) quenched from 850 to 900 °C in water and in water-based NaNO2 solutions at 25 °C and in canola oil at 50 °C. Additionally, square test probes (20×20×100 mm) were quenched from 550 °C in water. The test probes were equipped with embedded thermocouples for temperature-versus-time data logging at the core, one-quarter thickness and 1 mm below the surface. In each experiment, the data recordings from the core and near-surface thermocouples were employed for the temperature calculations while the data from the one-quarter thickness thermocouple were employed for model validity verifications. In all cases, the calculated temperature distributions showed good correlations with the experimentally obtained values. Based on the results of this work, it is concluded that this approach constitutes a simple, quick and efficient tool for estimating transient surface and radial temperature distributions and represents a useful resource for quenchant cooling rate calculations and heat transfer characterizations. Title: Estimation of Transient Temperature Distribution during Quenching, via a Parabolic Model Author: Lozano, Diego E., Martinez-Solis, Gabriela, Mercado-Solis, Rafael David, Colás, Rafael, Totten, George E. Year: 2015 A material-independent model to estimate the transient temperature distribution in a test probe quenched by immersion is presented in this study. This model is based on the assumption that, under one-dimensional unsteady heat conduction, the radial temperature distribution at the end of an interval belongs to the equation of a parabola. The model was validated using AISI 304 stainless steel test probes (Φ8×40 mm and Φ12×60 mm) quenched from 850 to 900 °C in water and in water-based NaNO2 solutions at 25 °C and in canola oil at 50 °C. Additionally, square test probes (20×20×100 mm) were quenched from 550 °C in water. The test probes were equipped with embedded thermocouples for temperature-versus-time data logging at the core, one-quarter thickness and 1 mm below the surface. In each experiment, the data recordings from the core and near-surface thermocouples were employed for the temperature calculations while the data from the one-quarter thickness thermocouple were employed for model validity verifications. In all cases, the calculated temperature distributions showed good correlations with the experimentally obtained values. Based on the results of this work, it is concluded that this approach constitutes a simple, quick and efficient tool for estimating transient surface and radial temperature distributions and represents a useful resource for quenchant cooling rate calculations and heat transfer characterizations. Close

• 18. [Article] Solder Material Experiencing Low Temperature Inelastic Stress and Random Vibration Loading: Predicted Remaining Useful Lifetime

  Although there exist promising ways to avoid inelastic strains in solder joints of the second level interconnections in IC package designs, it still appears more typical than not that the peripheral joints ...

  Citation × Citation Citation Abstract Copy Title: Solder Material Experiencing Low Temperature Inelastic Stress and Random Vibration Loading: Predicted Remaining Useful Lifetime Author: Suhir, Ephraim, Ghaffarian, Reza, Yi, Sung Year: 2017 Although there exist promising ways to avoid inelastic strains in solder joints of the second level interconnections in IC package designs, it still appears more typical than not that the peripheral joints of a package/PCB assembly experience inelastic strains. This takes place at low temperature conditions, when the deviation from the high fabrication temperature is the largest and the induced thermal stresses are the highest. On the other hand, it is well known that it is the combination of low temperatures and repetitive dynamic loading that accelerate dramatically the propagation of fatigue cracks, whether elastic or inelastic. Accordingly, a modification of the recently suggested Boltzmann–Arrhenius–Zhurkov model is developed for the evaluation of the remaining useful lifetime of the second level solder joint interconnection whose peripheral joints experience inelastic strains. The experimental basis of the approach is the highly focused and highly cost-effective failure-oriented-accelerated-testing (FOAT). The FOAT specimens are subjected in our methodology to the combined action of low temperatures (not to elevated temperatures, as in the classical Arrhenius model) and random vibrations with the given input energy spectrum. The suggested methodology is viewed as a possible, effective and attractive alternative to temperature cycling. As long as inelastic deformations take place, it is assumed that it is these deformations that determine the fatigue lifetime of the solder material, and the state of stress in the elastic mid-portion of the assembly does not have to be accounted for. The roles of the size and stiffness of this mid-portion have to be considered, however, when determining the very existence and establishing the size of the inelastic zones at the peripheral portions of the designs. The general concept is illustrated by a numerical example. Although this example is carried out for a ball-grid-array design, it is applicable to highly popular column-grid-array (CGA) and quad-flat-no-lead (QFN) designs as well. It is noteworthy that it is much easier to avoid inelastic strains in CGA and QFN structures than in the addressed BGA design. The random vibrations are considered in the developed methodology as a white noise of the given (m/s2)2/Hz—the ratio of the acceleration amplitudes squared to the vibration frequency. © 2016, Springer Science+Business Media New York. Title: Solder Material Experiencing Low Temperature Inelastic Stress and Random Vibration Loading: Predicted Remaining Useful Lifetime Author: Suhir, Ephraim, Ghaffarian, Reza, Yi, Sung Year: 2017 Although there exist promising ways to avoid inelastic strains in solder joints of the second level interconnections in IC package designs, it still appears more typical than not that the peripheral joints of a package/PCB assembly experience inelastic strains. This takes place at low temperature conditions, when the deviation from the high fabrication temperature is the largest and the induced thermal stresses are the highest. On the other hand, it is well known that it is the combination of low temperatures and repetitive dynamic loading that accelerate dramatically the propagation of fatigue cracks, whether elastic or inelastic. Accordingly, a modification of the recently suggested Boltzmann–Arrhenius–Zhurkov model is developed for the evaluation of the remaining useful lifetime of the second level solder joint interconnection whose peripheral joints experience inelastic strains. The experimental basis of the approach is the highly focused and highly cost-effective failure-oriented-accelerated-testing (FOAT). The FOAT specimens are subjected in our methodology to the combined action of low temperatures (not to elevated temperatures, as in the classical Arrhenius model) and random vibrations with the given input energy spectrum. The suggested methodology is viewed as a possible, effective and attractive alternative to temperature cycling. As long as inelastic deformations take place, it is assumed that it is these deformations that determine the fatigue lifetime of the solder material, and the state of stress in the elastic mid-portion of the assembly does not have to be accounted for. The roles of the size and stiffness of this mid-portion have to be considered, however, when determining the very existence and establishing the size of the inelastic zones at the peripheral portions of the designs. The general concept is illustrated by a numerical example. Although this example is carried out for a ball-grid-array design, it is applicable to highly popular column-grid-array (CGA) and quad-flat-no-lead (QFN) designs as well. It is noteworthy that it is much easier to avoid inelastic strains in CGA and QFN structures than in the addressed BGA design. The random vibrations are considered in the developed methodology as a white noise of the given (m/s2)2/Hz—the ratio of the acceleration amplitudes squared to the vibration frequency. © 2016, Springer Science+Business Media New York. Close

• 19. [Article] Evaluation of Large‑Scale Meteorological Patterns Associated with Temperature Extremes in the NARCCAP Regional Climate Model Simulations

  Large-scale meteorological patterns (LSMPs) associated with temperature extremes are evaluated in a suite of regional climate model (RCM) simulations contributing to the North American Regional Climate ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of Large‑Scale Meteorological Patterns Associated with Temperature Extremes in the NARCCAP Regional Climate Model Simulations Author: Loikith, Paul C., Waliser, Duane E., Lee, Huikyo, Neelin, J. David, Lintner, Benjamin, McGinnis, Seth, Mears, Linda, Kim, Jinwon Year: 2015 Large-scale meteorological patterns (LSMPs) associated with temperature extremes are evaluated in a suite of regional climate model (RCM) simulations contributing to the North American Regional Climate Change Assessment Program. LSMPs are characterized through composites of surface air temperature, sea level pressure, and 500 hPa geopotential height anomalies concurrent with extreme temperature days. Six of the seventeen RCM simulations are driven by boundary conditions from reanalysis while the other eleven are driven by one of four global climate models (GCMs). Four illustrative case studies are analyzed in detail. Model fidelity in LSMP spatial representation is high for cold winter extremes near Chicago. Winter warm extremes are captured by most RCMs in northern California, with some notable exceptions. Model fidelity is lower for cool summer days near Houston and extreme summer heat events in the Ohio Valley. Physical interpretation of these patterns and identification of wellsimulated cases, such as for Chicago, boosts confidence in the ability of these models to simulate days in the tails of the temperature distribution. Results appear consistent with the expectation that the ability of an RCM to reproduce a realistically shaped frequency distribution for temperature, especially at the tails, is related to its fidelity in simulating LMSPs. Each ensemble member is ranked for its ability to reproduce LSMPs associated with observed warm and cold extremes, identifying systematically high performing RCMs and the GCMs that provide superior boundary forcing. The methodology developed here provides a framework for identifying regions where further process-based evaluation would improve the understanding of simulation error and help guide future model improvement and downscaling efforts. Title: Evaluation of Large‑Scale Meteorological Patterns Associated with Temperature Extremes in the NARCCAP Regional Climate Model Simulations Author: Loikith, Paul C., Waliser, Duane E., Lee, Huikyo, Neelin, J. David, Lintner, Benjamin, McGinnis, Seth, Mears, Linda, Kim, Jinwon Year: 2015 Large-scale meteorological patterns (LSMPs) associated with temperature extremes are evaluated in a suite of regional climate model (RCM) simulations contributing to the North American Regional Climate Change Assessment Program. LSMPs are characterized through composites of surface air temperature, sea level pressure, and 500 hPa geopotential height anomalies concurrent with extreme temperature days. Six of the seventeen RCM simulations are driven by boundary conditions from reanalysis while the other eleven are driven by one of four global climate models (GCMs). Four illustrative case studies are analyzed in detail. Model fidelity in LSMP spatial representation is high for cold winter extremes near Chicago. Winter warm extremes are captured by most RCMs in northern California, with some notable exceptions. Model fidelity is lower for cool summer days near Houston and extreme summer heat events in the Ohio Valley. Physical interpretation of these patterns and identification of wellsimulated cases, such as for Chicago, boosts confidence in the ability of these models to simulate days in the tails of the temperature distribution. Results appear consistent with the expectation that the ability of an RCM to reproduce a realistically shaped frequency distribution for temperature, especially at the tails, is related to its fidelity in simulating LMSPs. Each ensemble member is ranked for its ability to reproduce LSMPs associated with observed warm and cold extremes, identifying systematically high performing RCMs and the GCMs that provide superior boundary forcing. The methodology developed here provides a framework for identifying regions where further process-based evaluation would improve the understanding of simulation error and help guide future model improvement and downscaling efforts. Close

• 20. [Article] A Metabolic Hypothesis for the Evolution of Temperature Effects on the Arterial PCO2 and pH of Vertebrate Ectotherms

  Body temperature increases in ectothermic vertebrates characteristically lead to both increases in arterial PCO2 (PaCO2) and declines in resting arterial pH (pHa) of about 0.017 pH units/°C increase in ...

  Citation × Citation Citation Abstract Copy Title: A Metabolic Hypothesis for the Evolution of Temperature Effects on the Arterial PCO2 and pH of Vertebrate Ectotherms Author: Hillman, Stanley S., Hedrick, Michael Scott Year: 2017 Body temperature increases in ectothermic vertebrates characteristically lead to both increases in arterial PCO2 (PaCO2) and declines in resting arterial pH (pHa) of about 0.017 pH units/°C increase in temperature. This ‘alphastat’ pH pattern has previously been interpreted as being evolutionarily-driven by the maintenance of a constant protonation state on the imidazole moiety of histidine protein residues, hence stabilizing protein structure-function. Analysis of the existing data for interclass responses of ectothermic vertebrates show different degrees of PaCO2 increases and pH declines with temperature between the classes with reptiles>amphibians>fish. The PaCO2 at the temperature where maximal aerobic metabolism (VO2max) is achieved is significantly and positively correlated with temperature for all vertebrate classes. For ectotherms, the PaCO2 where VO2max is greatest is also correlated with VO2max indicating there is an increased driving force for CO2 efflux that is lowest in fish, intermediate in amphibians and highest in reptiles. The pattern of increased PaCO2 and the resultant reduction of pHa to increased body temperature would serve to increase CO2 efflux, O2 delivery, blood buffering capacity and maintain ventilatory scope. This represents a new hypothesis for the selective advantage of arterial pH regulation from a systems physiology perspective in addition to the advantages of maintenance of protein structure-function. Title: A Metabolic Hypothesis for the Evolution of Temperature Effects on the Arterial PCO2 and pH of Vertebrate Ectotherms Author: Hillman, Stanley S., Hedrick, Michael Scott Year: 2017 Body temperature increases in ectothermic vertebrates characteristically lead to both increases in arterial PCO2 (PaCO2) and declines in resting arterial pH (pHa) of about 0.017 pH units/°C increase in temperature. This ‘alphastat’ pH pattern has previously been interpreted as being evolutionarily-driven by the maintenance of a constant protonation state on the imidazole moiety of histidine protein residues, hence stabilizing protein structure-function. Analysis of the existing data for interclass responses of ectothermic vertebrates show different degrees of PaCO2 increases and pH declines with temperature between the classes with reptiles>amphibians>fish. The PaCO2 at the temperature where maximal aerobic metabolism (VO2max) is achieved is significantly and positively correlated with temperature for all vertebrate classes. For ectotherms, the PaCO2 where VO2max is greatest is also correlated with VO2max indicating there is an increased driving force for CO2 efflux that is lowest in fish, intermediate in amphibians and highest in reptiles. The pattern of increased PaCO2 and the resultant reduction of pHa to increased body temperature would serve to increase CO2 efflux, O2 delivery, blood buffering capacity and maintain ventilatory scope. This represents a new hypothesis for the selective advantage of arterial pH regulation from a systems physiology perspective in addition to the advantages of maintenance of protein structure-function. Close

• 21. [Article] Temperature Changes in Human Skeletal Muscle during Single Leg Dynamic Knee Extension Exercise

  49 pages. A thesis presented to the Department of Uman Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Arts, Summer ...

  Citation × Citation Citation Abstract Copy Title: Temperature Changes in Human Skeletal Muscle during Single Leg Dynamic Knee Extension Exercise Author: Peck, Mairin Year: 2015 49 pages. A thesis presented to the Department of Uman Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Arts, Summer 2015. Title: Temperature Changes in Human Skeletal Muscle during Single Leg Dynamic Knee Extension Exercise Author: Peck, Mairin Year: 2015 49 pages. A thesis presented to the Department of Uman Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Arts, Summer 2015. Close

• 22. [Article] Estimation of Surface Water Temperature of the Tigris River System in Iraq

  Monitoring surface water temperatures (Tw) in lakes, rivers, and reservoirs is a key component of environmental management and influences water quality by affecting bio-geo chemical reaction rates, altering ...

  Citation × Citation Citation Abstract Copy Title: Estimation of Surface Water Temperature of the Tigris River System in Iraq Author: Al-Murib, M., Wells, Scott A., Talke, Stefan A. Year: 2017 Monitoring surface water temperatures (Tw) in lakes, rivers, and reservoirs is a key component of environmental management and influences water quality by affecting bio-geo chemical reaction rates, altering the saturation concentration of dissolved oxygen (DO), and influencing the susceptibility of fish to disease. Temperatures in the Tigris River, one of the largest rivers in the Middle East, are influenced by factors such as heat fluxes at the air-water and human activities such as direct discharge of water to the river. However, modeling and management of water temperature is limited by a paucity of in-situ data, which prevents calibration of models. In this study, we infill data gaps by estimating Tw using the thermal bands of both the Landsat 5 TM and Landsat 7 ETM+ sensors. These satellite-based estimates, typically measured once or twice a month with 60-120m resolution, are then used to develop a regression model that relates daily water temperature to daily air temperature and river flow. These estimates are used to define the Tw boundary conditions for a hydrodynamic and water quality model of the Tigris River based on a 2D implementation of the CE-QUAL-W2 (W2) numerical model. Initial results suggest that there is a significant agreement between modeled and remotely estimated data of Tw. Results suggest that short-wave solar radiation is the most important factor that controls seasonal Tw variations. However, anthropogenic influence is observed as a result of return irrigation flows and flows from Tharthar Lake. Title: Estimation of Surface Water Temperature of the Tigris River System in Iraq Author: Al-Murib, M., Wells, Scott A., Talke, Stefan A. Year: 2017 Monitoring surface water temperatures (Tw) in lakes, rivers, and reservoirs is a key component of environmental management and influences water quality by affecting bio-geo chemical reaction rates, altering the saturation concentration of dissolved oxygen (DO), and influencing the susceptibility of fish to disease. Temperatures in the Tigris River, one of the largest rivers in the Middle East, are influenced by factors such as heat fluxes at the air-water and human activities such as direct discharge of water to the river. However, modeling and management of water temperature is limited by a paucity of in-situ data, which prevents calibration of models. In this study, we infill data gaps by estimating Tw using the thermal bands of both the Landsat 5 TM and Landsat 7 ETM+ sensors. These satellite-based estimates, typically measured once or twice a month with 60-120m resolution, are then used to develop a regression model that relates daily water temperature to daily air temperature and river flow. These estimates are used to define the Tw boundary conditions for a hydrodynamic and water quality model of the Tigris River based on a 2D implementation of the CE-QUAL-W2 (W2) numerical model. Initial results suggest that there is a significant agreement between modeled and remotely estimated data of Tw. Results suggest that short-wave solar radiation is the most important factor that controls seasonal Tw variations. However, anthropogenic influence is observed as a result of return irrigation flows and flows from Tharthar Lake. Close

• 23. [Article] Can Significant Trends be Detected in Surface Air Temperature and Precipitation Over South America in Recent Decades?

  Trends in near-surface air temperature and precipitation over South America are examined for the periods 1975–2004 and 1955–2004, respectively, using multiple observational and climate model data sets. ...

  Citation × Citation Citation Abstract Copy Title: Can Significant Trends be Detected in Surface Air Temperature and Precipitation Over South America in Recent Decades? Author: de Barros Soares, Daniel, Lee, Huikyo, Loikith, Paul C., Barkhordarian, Armineh, Mechoso, Carlos R. Year: 2016 Trends in near-surface air temperature and precipitation over South America are examined for the periods 1975–2004 and 1955–2004, respectively, using multiple observational and climate model data sets. The results for observed near-surface air temperature show an overall warming trend over much of the continent, with the largest magnitudes over central Brazil. These observed trends are found to be statistically significant using pre-industrial control simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) as the baseline to estimate natural climate variability. The observed trends are compared with those obtained in natural-only CMIP5 simulations, in which only natural forcings (i.e. volcanoes and solar variability) are included, and in historical CMIP5 simulations, in which anthropogenic forcings (i.e. changes in the atmospheric composition) are further incorporated. The historical CMIP5 simulations are more successful in capturing the observed temperature trends than the simulations with natural forcings only. It is suggested that anthropogenic warming is already evident over much of South America. Unlike the warming trends, observed precipitation trends over South America are less spatially coherent with both negative and positive values across the continent. Significant positive trends are found over South America in only one of the data sets used, and over a region that roughly encompasses the southern part of La Plata Basin (southern Brazil, Uruguay, and northeastern Argentina) in all data sets used. The historical CMIP5 simulations do not capture this feature. No firm conclusions are reached, therefore, for anthropogenic influences on precipitation changes in the period selected for study. Title: Can Significant Trends be Detected in Surface Air Temperature and Precipitation Over South America in Recent Decades? Author: de Barros Soares, Daniel, Lee, Huikyo, Loikith, Paul C., Barkhordarian, Armineh, Mechoso, Carlos R. Year: 2016 Trends in near-surface air temperature and precipitation over South America are examined for the periods 1975–2004 and 1955–2004, respectively, using multiple observational and climate model data sets. The results for observed near-surface air temperature show an overall warming trend over much of the continent, with the largest magnitudes over central Brazil. These observed trends are found to be statistically significant using pre-industrial control simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) as the baseline to estimate natural climate variability. The observed trends are compared with those obtained in natural-only CMIP5 simulations, in which only natural forcings (i.e. volcanoes and solar variability) are included, and in historical CMIP5 simulations, in which anthropogenic forcings (i.e. changes in the atmospheric composition) are further incorporated. The historical CMIP5 simulations are more successful in capturing the observed temperature trends than the simulations with natural forcings only. It is suggested that anthropogenic warming is already evident over much of South America. Unlike the warming trends, observed precipitation trends over South America are less spatially coherent with both negative and positive values across the continent. Significant positive trends are found over South America in only one of the data sets used, and over a region that roughly encompasses the southern part of La Plata Basin (southern Brazil, Uruguay, and northeastern Argentina) in all data sets used. The historical CMIP5 simulations do not capture this feature. No firm conclusions are reached, therefore, for anthropogenic influences on precipitation changes in the period selected for study. Close

• 24. [Article] Towards Systematic Prediction of Urban Heat Islands: Grounding Measurements, Assessing Modeling Techniques

  While there exists extensive assessment of urban heat, we observe myriad methods for describing thermal distribution, factors that mediate temperatures, and potential impacts on urban populations. In addition, ...

  Citation × Citation Citation Abstract Copy Title: Towards Systematic Prediction of Urban Heat Islands: Grounding Measurements, Assessing Modeling Techniques Author: Voelkel, Jackson, Shandas, Vivek Year: 2017 While there exists extensive assessment of urban heat, we observe myriad methods for describing thermal distribution, factors that mediate temperatures, and potential impacts on urban populations. In addition, the limited spatial and temporal resolution of satellite-derived heat measurements may limit the capacity of decision makers to take effective actions for reducing mortalities in vulnerable populations whose locations require highly-refined measurements. Needed are high resolution spatial and temporal information for urban heat. In this study, we ask three questions: (1) how do urban heat islands vary throughout the day? (2) what statistical methods best explain the presence of temperatures at sub-meter spatial scales; and (3) what landscape features help to explain variation in urban heat islands? Using vehicle-based temperature measurements at three periods of the day in the Pacific Northwest city of Portland, Oregon (USA), we incorporate LiDAR-derived datasets, and evaluate three statistical techniques for modeling and predicting variation in temperatures during a heat wave. Our results indicate that the random forest technique best predicts temperatures, and that the evening model best explains the variation in temperature. The results suggest that ground-based measurements provide high levels of accuracy for describing the distribution of urban heat, its temporal variation, and specific locations where targeted interventions with communities can reduce mortalities from heat events. Title: Towards Systematic Prediction of Urban Heat Islands: Grounding Measurements, Assessing Modeling Techniques Author: Voelkel, Jackson, Shandas, Vivek Year: 2017 While there exists extensive assessment of urban heat, we observe myriad methods for describing thermal distribution, factors that mediate temperatures, and potential impacts on urban populations. In addition, the limited spatial and temporal resolution of satellite-derived heat measurements may limit the capacity of decision makers to take effective actions for reducing mortalities in vulnerable populations whose locations require highly-refined measurements. Needed are high resolution spatial and temporal information for urban heat. In this study, we ask three questions: (1) how do urban heat islands vary throughout the day? (2) what statistical methods best explain the presence of temperatures at sub-meter spatial scales; and (3) what landscape features help to explain variation in urban heat islands? Using vehicle-based temperature measurements at three periods of the day in the Pacific Northwest city of Portland, Oregon (USA), we incorporate LiDAR-derived datasets, and evaluate three statistical techniques for modeling and predicting variation in temperatures during a heat wave. Our results indicate that the random forest technique best predicts temperatures, and that the evening model best explains the variation in temperature. The results suggest that ground-based measurements provide high levels of accuracy for describing the distribution of urban heat, its temporal variation, and specific locations where targeted interventions with communities can reduce mortalities from heat events. Close

• 25. [Article] The Effects of Anthropogenic Stressors on Mercury Concentrations and Community Composition of Freshwater Zooplankton

  Methylmercury (MeHg) bioaccumulation in freshwater aquatic systems is impacted by anthropogenic stressors, including climate change and excess nutrients. The goal of this study was to determine how warmer ...

  Citation × Citation Citation Abstract Copy Title: The Effects of Anthropogenic Stressors on Mercury Concentrations and Community Composition of Freshwater Zooplankton Author: Jordan, Meredith Powers Year: 2016 Methylmercury (MeHg) bioaccumulation in freshwater aquatic systems is impacted by anthropogenic stressors, including climate change and excess nutrients. The goal of this study was to determine how warmer water temperatures and excess nutrients would impact zooplankton communities and phytoplankton concentrations, and in turn increase or decrease MeHg concentrations in freshwater zooplankton. I used a 2x2 factorial design to determine if the interaction of temperature and nutrients would impact plankton metrics and zooplankton MeHg concentrations. Mesocosms were filled with Hg-contaminated water and plankton from Cottage Grove Reservoir, Oregon, U.S.A, a waterbody that has experienced decades of elevated MeHg concentrations and corresponding fish consumption advisories due to run-off from Black Butte Mine tailings, located within the watershed. Treatment combinations of warmer temperature (increased by 0.5°C) and nutrient addition (a single pulse of excess nitrogen and phosphorous), control, and a combination of temperature and nutrients were applied to mesocosms. While plankton did respond to treatments, zooplankton biomass and phytoplankton concentrations did not have significant relationships to MeHg concentrations. However, a significant interactive effect of nutrients and temperature was present: nutrients appeared to buffer against increased MeHg concentrations when temperature was elevated. The mechanisms for this interaction appear to be related to a shift to larger body size and an increase in abundance of Daphnia over copepods. Findings suggest that community composition and species-specific differences in both zooplankton and phytoplankton could play a role in MeHg transfer to higher trophic levels. Title: The Effects of Anthropogenic Stressors on Mercury Concentrations and Community Composition of Freshwater Zooplankton Author: Jordan, Meredith Powers Year: 2016 Methylmercury (MeHg) bioaccumulation in freshwater aquatic systems is impacted by anthropogenic stressors, including climate change and excess nutrients. The goal of this study was to determine how warmer water temperatures and excess nutrients would impact zooplankton communities and phytoplankton concentrations, and in turn increase or decrease MeHg concentrations in freshwater zooplankton. I used a 2x2 factorial design to determine if the interaction of temperature and nutrients would impact plankton metrics and zooplankton MeHg concentrations. Mesocosms were filled with Hg-contaminated water and plankton from Cottage Grove Reservoir, Oregon, U.S.A, a waterbody that has experienced decades of elevated MeHg concentrations and corresponding fish consumption advisories due to run-off from Black Butte Mine tailings, located within the watershed. Treatment combinations of warmer temperature (increased by 0.5°C) and nutrient addition (a single pulse of excess nitrogen and phosphorous), control, and a combination of temperature and nutrients were applied to mesocosms. While plankton did respond to treatments, zooplankton biomass and phytoplankton concentrations did not have significant relationships to MeHg concentrations. However, a significant interactive effect of nutrients and temperature was present: nutrients appeared to buffer against increased MeHg concentrations when temperature was elevated. The mechanisms for this interaction appear to be related to a shift to larger body size and an increase in abundance of Daphnia over copepods. Findings suggest that community composition and species-specific differences in both zooplankton and phytoplankton could play a role in MeHg transfer to higher trophic levels. Close

• 26. [Article] Climate Change Assessment in Columbia River Basin (CRB) Using Copula Based on Coupling of Temperature and Precipitation

  The multi downscaled-scenario products allow us to better assess the uncertainty of the variations of precipitation and temperature in the current and future periods. Joint Probability distribution functions ...

  Citation × Citation Citation Abstract Copy Title: Climate Change Assessment in Columbia River Basin (CRB) Using Copula Based on Coupling of Temperature and Precipitation Author: Qin, Yueyue Year: 2015 The multi downscaled-scenario products allow us to better assess the uncertainty of the variations of precipitation and temperature in the current and future periods. Joint Probability distribution functions (PDFs), of both the climatic variables, might help better understand the interdependence of the two, and thus in-turn help in accessing the future with confidence. In the present study, we have used multi-modelled statistically downscaled ensemble of precipitation and temperature variables. The dataset used is multi-model ensemble of 10 Global Climate Models (GCMs) downscaled product from CMIP5 daily dataset, using the Bias Correction and Spatial Downscaling (BCSD) technique, generated at Portland State University. The multi-model ensemble PDFs of both precipitation and temperature is evaluated for summer (dry) and winter (wet) periods for 10 sub-basins across Columbia River Basin (CRB). Eventually, Copula is applied to establish the joint distribution of two variables on multi-model ensemble data. Results have indicated that the probabilistic distribution helps remove the limitations on marginal distributions of variables in question and helps in better prediction. The joint distribution is then used to estimate the change in trends of said variables in future, along with estimation of the probabilities of the given change. The joint distribution trends are varied, but certainly positive, for summer and winter time scales based on sub-basins. Dry season, generally, is indicating towards higher positive changes in precipitation than temperature (as compared to historical) across sub-basins with wet season inferring otherwise. Probabilities of changes in future, as estimated by the joint precipitation and temperature, also indicates varied degree and forms during dry season whereas the wet season is rather constant across all the sub-basins. Title: Climate Change Assessment in Columbia River Basin (CRB) Using Copula Based on Coupling of Temperature and Precipitation Author: Qin, Yueyue Year: 2015 The multi downscaled-scenario products allow us to better assess the uncertainty of the variations of precipitation and temperature in the current and future periods. Joint Probability distribution functions (PDFs), of both the climatic variables, might help better understand the interdependence of the two, and thus in-turn help in accessing the future with confidence. In the present study, we have used multi-modelled statistically downscaled ensemble of precipitation and temperature variables. The dataset used is multi-model ensemble of 10 Global Climate Models (GCMs) downscaled product from CMIP5 daily dataset, using the Bias Correction and Spatial Downscaling (BCSD) technique, generated at Portland State University. The multi-model ensemble PDFs of both precipitation and temperature is evaluated for summer (dry) and winter (wet) periods for 10 sub-basins across Columbia River Basin (CRB). Eventually, Copula is applied to establish the joint distribution of two variables on multi-model ensemble data. Results have indicated that the probabilistic distribution helps remove the limitations on marginal distributions of variables in question and helps in better prediction. The joint distribution is then used to estimate the change in trends of said variables in future, along with estimation of the probabilities of the given change. The joint distribution trends are varied, but certainly positive, for summer and winter time scales based on sub-basins. Dry season, generally, is indicating towards higher positive changes in precipitation than temperature (as compared to historical) across sub-basins with wet season inferring otherwise. Probabilities of changes in future, as estimated by the joint precipitation and temperature, also indicates varied degree and forms during dry season whereas the wet season is rather constant across all the sub-basins. Close

• 27. [Article] The Role of Atmospheric Circulation Patterns in Agroclimate Variability in Finland, 1961-2011

  This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation ...

  Citation × Citation Citation Abstract Copy Title: The Role of Atmospheric Circulation Patterns in Agroclimate Variability in Finland, 1961-2011 Author: Irannezhad, Masoud, Chen, Deliang, Kløve, Bjørn Year: 2016 This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation patterns. Changes in summer (June–August) climate partially explain changes in growing season daily temperature sum and daily precipitation sum over Finland, which naturally decreased from south to north. On a national scale, growing season warmed and became wetter during 1961–2011, as growing season daily temperature sum and daily precipitation sum significantly (p < 0.05) increased by 5.01 ± 3.17°C year–1 and 1.39 ± 0.91 mm year–1, respectively. The East Atlantic pattern was the most influential atmospheric circulation pattern for variations in growing season daily temperature sum (rho = 0.40) across Finland and the East Atlantic/West Russia pattern was most influential for growing season daily precipitation sum variability (rho = –0.54). There were significant (p < 0.05) increasing trends in growing season daily temperature sum and daily precipitation sum throughout Finland during 1961–2011. Increased growing season daily temperature sum was mainly observed in northern, central, western, eastern and coastal areas of south-western Finland. This warming was positively associated with the East Atlantic pattern in the north, centre and south, but negatively associated with the East Atlantic/West Russia pattern in eastern Finland. Increased GSP mostly occurred in southern, eastern, western, central, northern and north-western Finland. These wetting trends were positively correlated with the East Atlantic pattern in the north and negatively correlated with the Polar pattern in the south and the East Atlantic/West Russia pattern in the east, west, centre and north-east of Finland. The overall agroclimatic year-to-year variability in Finland between 1961 and 2011 was mostly linked to variations in the East Atlantic and East Atlantic/West Russia patterns. Title: The Role of Atmospheric Circulation Patterns in Agroclimate Variability in Finland, 1961-2011 Author: Irannezhad, Masoud, Chen, Deliang, Kløve, Bjørn Year: 2016 This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation patterns. Changes in summer (June–August) climate partially explain changes in growing season daily temperature sum and daily precipitation sum over Finland, which naturally decreased from south to north. On a national scale, growing season warmed and became wetter during 1961–2011, as growing season daily temperature sum and daily precipitation sum significantly (p < 0.05) increased by 5.01 ± 3.17°C year–1 and 1.39 ± 0.91 mm year–1, respectively. The East Atlantic pattern was the most influential atmospheric circulation pattern for variations in growing season daily temperature sum (rho = 0.40) across Finland and the East Atlantic/West Russia pattern was most influential for growing season daily precipitation sum variability (rho = –0.54). There were significant (p < 0.05) increasing trends in growing season daily temperature sum and daily precipitation sum throughout Finland during 1961–2011. Increased growing season daily temperature sum was mainly observed in northern, central, western, eastern and coastal areas of south-western Finland. This warming was positively associated with the East Atlantic pattern in the north, centre and south, but negatively associated with the East Atlantic/West Russia pattern in eastern Finland. Increased GSP mostly occurred in southern, eastern, western, central, northern and north-western Finland. These wetting trends were positively correlated with the East Atlantic pattern in the north and negatively correlated with the Polar pattern in the south and the East Atlantic/West Russia pattern in the east, west, centre and north-east of Finland. The overall agroclimatic year-to-year variability in Finland between 1961 and 2011 was mostly linked to variations in the East Atlantic and East Atlantic/West Russia patterns. Close

• 28. [Article] Comparison between Observed and Model-Simulated Atmospheric CirculationPatterns Associated with Extreme Temperature Days over North AmericaUsing CMIP5 Historical Simulations

  Circulation patterns associated with extreme temperature days over North America, as simulated by a suite of climate models, are compared with those obtained from observations. The authors analyze 17 coupled ...

  Citation × Citation Citation Abstract Copy Title: Comparison between Observed and Model-Simulated Atmospheric CirculationPatterns Associated with Extreme Temperature Days over North AmericaUsing CMIP5 Historical Simulations Author: Loikith, Paul C., Broccoli, Anthony J. Year: 2015 Circulation patterns associated with extreme temperature days over North America, as simulated by a suite of climate models, are compared with those obtained from observations. The authors analyze 17 coupled atmosphere–ocean general circulation models contributing to the fifth phase of the Coupled Model Intercomparison Project. Circulation patterns are defined as composites of anomalies in sea level pressure and 500-hPa geopotential height concurrent with days in the tails of temperature distribution. Several metrics used to systematically describe circulation patterns associated with extreme temperature days are applied to both the observed and model-simulated data. Additionally, self-organizing maps are employed as a means of comparing observed and model-simulated circulation patterns across the North American domain. In general, the multimodel ensemble resembles the observed patterns well, especially in areas removed from complex geographic features (e.g., mountains and coastlines). Individual model results vary; however, the majority of models capture the major features observed. The multimodel ensemble captures several key features, including regional variations in the strength and orientation of atmospheric circulation patterns associated with extreme temperatures, both near the surface and aloft, as well as variations with latitude and season. The results from this work suggest that these models can be used to comprehensively examine the role that changes in atmospheric circulation will play in projected changes in temperature extremes because of future anthropogenic climate warming. Title: Comparison between Observed and Model-Simulated Atmospheric CirculationPatterns Associated with Extreme Temperature Days over North AmericaUsing CMIP5 Historical Simulations Author: Loikith, Paul C., Broccoli, Anthony J. Year: 2015 Circulation patterns associated with extreme temperature days over North America, as simulated by a suite of climate models, are compared with those obtained from observations. The authors analyze 17 coupled atmosphere–ocean general circulation models contributing to the fifth phase of the Coupled Model Intercomparison Project. Circulation patterns are defined as composites of anomalies in sea level pressure and 500-hPa geopotential height concurrent with days in the tails of temperature distribution. Several metrics used to systematically describe circulation patterns associated with extreme temperature days are applied to both the observed and model-simulated data. Additionally, self-organizing maps are employed as a means of comparing observed and model-simulated circulation patterns across the North American domain. In general, the multimodel ensemble resembles the observed patterns well, especially in areas removed from complex geographic features (e.g., mountains and coastlines). Individual model results vary; however, the majority of models capture the major features observed. The multimodel ensemble captures several key features, including regional variations in the strength and orientation of atmospheric circulation patterns associated with extreme temperatures, both near the surface and aloft, as well as variations with latitude and season. The results from this work suggest that these models can be used to comprehensively examine the role that changes in atmospheric circulation will play in projected changes in temperature extremes because of future anthropogenic climate warming. Close

• 29. [Article] Reverse Gyrase is Not Necessary for Survival of Hyperthermophilic Archaeon Pyrococcus Furiosus

  Reverse gyrase is the only known topoisomerase enzyme with positive supercoiling activity on covalently-closed DNA. This positive supercoiling is required to prevent DNA from denaturation at high temperatures. ...

  Citation × Citation Citation Abstract Copy Title: Reverse Gyrase is Not Necessary for Survival of Hyperthermophilic Archaeon Pyrococcus Furiosus Author: Taghizadeh, Farshid, Bartlett, Michael S. Year: 2015 Reverse gyrase is the only known topoisomerase enzyme with positive supercoiling activity on covalently-closed DNA. This positive supercoiling is required to prevent DNA from denaturation at high temperatures. The gene that codes for this protein is present in all hyperthermophiles and absent from all mesophilic and thermophilic genomes, suggesting that this enzyme is the only hyperthermophile-specific protein. To investigate if this protein is vital for the cells, we knocked out its gene from the genome of living organism Pyrococcus furiosus. Pyrococcus furiosus is a hyperthermophilic archaeon that grows between 70°C to 103°C with an optimum growth temperature of 100°C. The knocking out process was done as follows. Recombinant DNA was made using Gibson Assembly technique. This DNA, which included a selection marker for ability to synthesize uracil, was used to transform Pyrococcus furiosus strain ‘COM1’. Uracil prototrophs were selected on growth medium lacking uracil, and the deletion of the target gene was confirmed using PCR. Mutants then were grown at different temperatures ranging from 75°C to 105°C and growth curves were compared to that of COM1. Although mutants do not survive at temperatures over 93°C, no significant difference was observed between the growth rate and density of COM1 and mutants in temperatures below that. We demonstrated that although reverse gyrase is not essential for cell survival, it shifts the maximum living temperature from 103°C to 93°C. Title: Reverse Gyrase is Not Necessary for Survival of Hyperthermophilic Archaeon Pyrococcus Furiosus Author: Taghizadeh, Farshid, Bartlett, Michael S. Year: 2015 Reverse gyrase is the only known topoisomerase enzyme with positive supercoiling activity on covalently-closed DNA. This positive supercoiling is required to prevent DNA from denaturation at high temperatures. The gene that codes for this protein is present in all hyperthermophiles and absent from all mesophilic and thermophilic genomes, suggesting that this enzyme is the only hyperthermophile-specific protein. To investigate if this protein is vital for the cells, we knocked out its gene from the genome of living organism Pyrococcus furiosus. Pyrococcus furiosus is a hyperthermophilic archaeon that grows between 70°C to 103°C with an optimum growth temperature of 100°C. The knocking out process was done as follows. Recombinant DNA was made using Gibson Assembly technique. This DNA, which included a selection marker for ability to synthesize uracil, was used to transform Pyrococcus furiosus strain ‘COM1’. Uracil prototrophs were selected on growth medium lacking uracil, and the deletion of the target gene was confirmed using PCR. Mutants then were grown at different temperatures ranging from 75°C to 105°C and growth curves were compared to that of COM1. Although mutants do not survive at temperatures over 93°C, no significant difference was observed between the growth rate and density of COM1 and mutants in temperatures below that. We demonstrated that although reverse gyrase is not essential for cell survival, it shifts the maximum living temperature from 103°C to 93°C. Close

• 30. [Article] Investigating Heat Shock Induced Double Strand Breaks in Caenorhabditis elegans Spermatocyte

  42 pages. A thesis presented to the Department of Biology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2...

  Citation × Citation Citation Abstract Copy Title: Investigating Heat Shock Induced Double Strand Breaks in Caenorhabditis elegans Spermatocyte Author: Schoellhorn, Kaycee Marie Year: 2017 42 pages. A thesis presented to the Department of Biology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2017 Title: Investigating Heat Shock Induced Double Strand Breaks in Caenorhabditis elegans Spermatocyte Author: Schoellhorn, Kaycee Marie Year: 2017 42 pages. A thesis presented to the Department of Biology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2017 Close

• 31. [Article] Long-Term Stability of 14YT-4Sc Alloy at High Temperature

  14YT alloy (Fe-14Cr-0.25wt.%Y2O3-0.4wt.%Ti) with 4 at.% Sc addition was previously reported to exhibit a nanoscale microstructure and high strength when annealed at temperatures up to 1000 °C (0.65Tm) ...

  Citation × Citation Citation Abstract Copy Title: Long-Term Stability of 14YT-4Sc Alloy at High Temperature Author: Li, Lulu, Xu, Weizong, Saber, Mostafa, Zhu, Yuntian, Koch, Carl C., Scattergood, Ronald O. Year: 2015 14YT alloy (Fe-14Cr-0.25wt.%Y2O3-0.4wt.%Ti) with 4 at.% Sc addition was previously reported to exhibit a nanoscale microstructure and high strength when annealed at temperatures up to 1000 °C (0.65Tm) for 1 hour. Here we report that the microstructure and mechanical behavior of 14YT-4Sc alloy after long-term annealing for up to 60 hours at 1000 °C. FIB analysis shows abnormal grain growth with annealing time, while a large fraction of the matrix still consists of nanoscale grains. TEM images reveal a slight growth of nano grains, with estimated grain growth exponent, n, to be 0.29. Sc-Ti-Y-O enriched nano oxide particles (nm) were observed in EDS mapping of the 14YT-4Sc-60h sample. The nano-structure retention at the high temperature of 1000 °C for 60 hours is attributed to these complex nano oxides. Title: Long-Term Stability of 14YT-4Sc Alloy at High Temperature Author: Li, Lulu, Xu, Weizong, Saber, Mostafa, Zhu, Yuntian, Koch, Carl C., Scattergood, Ronald O. Year: 2015 14YT alloy (Fe-14Cr-0.25wt.%Y2O3-0.4wt.%Ti) with 4 at.% Sc addition was previously reported to exhibit a nanoscale microstructure and high strength when annealed at temperatures up to 1000 °C (0.65Tm) for 1 hour. Here we report that the microstructure and mechanical behavior of 14YT-4Sc alloy after long-term annealing for up to 60 hours at 1000 °C. FIB analysis shows abnormal grain growth with annealing time, while a large fraction of the matrix still consists of nanoscale grains. TEM images reveal a slight growth of nano grains, with estimated grain growth exponent, n, to be 0.29. Sc-Ti-Y-O enriched nano oxide particles (nm) were observed in EDS mapping of the 14YT-4Sc-60h sample. The nano-structure retention at the high temperature of 1000 °C for 60 hours is attributed to these complex nano oxides. Close

• 32. [Article] Influence of Scandium Addition on the High-Temperature Grain Size Stabilization of Oxide-Dispersion-Strengthened (ODS) Ferritic Alloy

  The influence of 1–4 at% Sc addition on the thermal stability of mechanically alloyed ODS ferritic alloy was studied in this work. Sc addition was found to significantly stabilize grain size and microhardness ...

  Citation × Citation Citation Abstract Copy Title: Influence of Scandium Addition on the High-Temperature Grain Size Stabilization of Oxide-Dispersion-Strengthened (ODS) Ferritic Alloy Author: Li, Lulu, Xu, Weizong, Saber, Mostafa, Zhu, Yuntian, Koch, Carl C., Scattergood, Ronald O. Year: 2015 The influence of 1–4 at% Sc addition on the thermal stability of mechanically alloyed ODS ferritic alloy was studied in this work. Sc addition was found to significantly stabilize grain size and microhardness at high temperatures. Grain sizes of samples with 1 and 4 at% Sc was found maintained in the nanoscale range at temperatures up to 1000 °C with hardness maintained at 5.6 and 6.7 GPa, respectively. The detailed microstructure was also investigated from EDS elemental mapping, where nanofeatures [ScTiO] were observed, while nanosized [YTiO] particles were rarely seen. This is probably due to the concentration difference between Sc and Y, leading to the formation of [ScTiO] favoring that of [YTiO]. Precipitation was considered as the major source for the observed high temperature stabilization. In addition, 14YT–Sc alloys without large second phases such as Ti-oxide can exhibit better performance compared to conventional ODS materials. Title: Influence of Scandium Addition on the High-Temperature Grain Size Stabilization of Oxide-Dispersion-Strengthened (ODS) Ferritic Alloy Author: Li, Lulu, Xu, Weizong, Saber, Mostafa, Zhu, Yuntian, Koch, Carl C., Scattergood, Ronald O. Year: 2015 The influence of 1–4 at% Sc addition on the thermal stability of mechanically alloyed ODS ferritic alloy was studied in this work. Sc addition was found to significantly stabilize grain size and microhardness at high temperatures. Grain sizes of samples with 1 and 4 at% Sc was found maintained in the nanoscale range at temperatures up to 1000 °C with hardness maintained at 5.6 and 6.7 GPa, respectively. The detailed microstructure was also investigated from EDS elemental mapping, where nanofeatures [ScTiO] were observed, while nanosized [YTiO] particles were rarely seen. This is probably due to the concentration difference between Sc and Y, leading to the formation of [ScTiO] favoring that of [YTiO]. Precipitation was considered as the major source for the observed high temperature stabilization. In addition, 14YT–Sc alloys without large second phases such as Ti-oxide can exhibit better performance compared to conventional ODS materials. Close

• 33. [Article] Mixing Times of Organic Molecules Within Secondary Organic Aerosol Particles: A Global Planetary Boundary Layer Perspective

  When simulating the formation and life cycle of secondary organic aerosol (SOA) with chemical transport models, it is often assumed that organic molecules are well mixed within SOA particles on the timescale ...

  Citation × Citation Citation Abstract Copy Title: Mixing Times of Organic Molecules Within Secondary Organic Aerosol Particles: A Global Planetary Boundary Layer Perspective Author: Maclean, Adrian M., Butenhoff, Christopher L., Grayson, James W., Barsanti, Kelley, Jimenez, Jose L., Bertram, Allan K. Year: 2017 When simulating the formation and life cycle of secondary organic aerosol (SOA) with chemical transport models, it is often assumed that organic molecules are well mixed within SOA particles on the timescale of 1 h. While this assumption has been debated vigorously in the literature, the issue remains unresolved in part due to a lack of information on the mixing times within SOA particles as a function of both temperature and relative humidity. Using laboratory data, meteorological fields, and a chemical transport model, we estimated how often mixing times are < 1 h within SOA in the planetary boundary layer (PBL), the region of the atmosphere where SOA concentrations are on average the highest. First, a parameterization for viscosity as a function of temperature and RH was developed for α-pinene SOA using room-temperature and low-temperature viscosity data for α-pinene SOA generated in the laboratory using mass concentrations of ∼ 1000 µg m−3. Based on this parameterization, the mixing times within α-pinene SOA are < 1 h for 98.5 % and 99.9 % of the occurrences in the PBL during January and July, respectively, when concentrations are significant (total organic aerosol concentrations are > 0.5 µg m−3 at the surface). Next, as a starting point to quantify how often mixing times of organic molecules are < 1 h within α-pinene SOA generated using low, atmospherically relevant mass concentrations, we developed a temperature independent parameterization for viscosity using the room temperature viscosity data for α-pinene SOA generated in the laboratory using a mass concentration of ~70 μg m-3. Based on this temperature-independent parameterization, mixing times within α-pinene SOA are < 1 h for 27 and 19.5% of the occurrences in the PBL during January and July, respectively, when concentrations are significant. However, associated with these conclusions are several caveats, and due to these caveats we are unable to make strong conclusions about how often mixing times of organic molecules are < 1 h within pinene SOA generated using low, atmospherically relevant mass concentrations. Finally, a parameterization for viscosity of anthropogenic SOA as a function of temperature and RH was developed using sucrose–water data. Based on this parameterization, and assuming sucrose is a good proxy for anthropogenic SOA, 70 and 83% of the mixing times within anthropogenic SOA in the PBL are < 1 h for January and July, respectively, when concentrations are significant. These percentages are likely lower limits due to the assumptions used to calculate mixing times. Title: Mixing Times of Organic Molecules Within Secondary Organic Aerosol Particles: A Global Planetary Boundary Layer Perspective Author: Maclean, Adrian M., Butenhoff, Christopher L., Grayson, James W., Barsanti, Kelley, Jimenez, Jose L., Bertram, Allan K. Year: 2017 When simulating the formation and life cycle of secondary organic aerosol (SOA) with chemical transport models, it is often assumed that organic molecules are well mixed within SOA particles on the timescale of 1 h. While this assumption has been debated vigorously in the literature, the issue remains unresolved in part due to a lack of information on the mixing times within SOA particles as a function of both temperature and relative humidity. Using laboratory data, meteorological fields, and a chemical transport model, we estimated how often mixing times are < 1 h within SOA in the planetary boundary layer (PBL), the region of the atmosphere where SOA concentrations are on average the highest. First, a parameterization for viscosity as a function of temperature and RH was developed for α-pinene SOA using room-temperature and low-temperature viscosity data for α-pinene SOA generated in the laboratory using mass concentrations of ∼ 1000 µg m−3. Based on this parameterization, the mixing times within α-pinene SOA are < 1 h for 98.5 % and 99.9 % of the occurrences in the PBL during January and July, respectively, when concentrations are significant (total organic aerosol concentrations are > 0.5 µg m−3 at the surface). Next, as a starting point to quantify how often mixing times of organic molecules are < 1 h within α-pinene SOA generated using low, atmospherically relevant mass concentrations, we developed a temperature independent parameterization for viscosity using the room temperature viscosity data for α-pinene SOA generated in the laboratory using a mass concentration of ~70 μg m-3. Based on this temperature-independent parameterization, mixing times within α-pinene SOA are < 1 h for 27 and 19.5% of the occurrences in the PBL during January and July, respectively, when concentrations are significant. However, associated with these conclusions are several caveats, and due to these caveats we are unable to make strong conclusions about how often mixing times of organic molecules are < 1 h within pinene SOA generated using low, atmospherically relevant mass concentrations. Finally, a parameterization for viscosity of anthropogenic SOA as a function of temperature and RH was developed using sucrose–water data. Based on this parameterization, and assuming sucrose is a good proxy for anthropogenic SOA, 70 and 83% of the mixing times within anthropogenic SOA in the PBL are < 1 h for January and July, respectively, when concentrations are significant. These percentages are likely lower limits due to the assumptions used to calculate mixing times. Close

• 34. [Article] The Effect of Seasonal Temperature Changes on the Light-Use Efficiency of Two Coral Communities

  37 pages. A thesis presented to the Departments of Biology and Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor ...

  Citation × Citation Citation Abstract Copy Title: The Effect of Seasonal Temperature Changes on the Light-Use Efficiency of Two Coral Communities Author: Saraceno, Hannah McKenzie Year: 2017 37 pages. A thesis presented to the Departments of Biology and Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2017 Title: The Effect of Seasonal Temperature Changes on the Light-Use Efficiency of Two Coral Communities Author: Saraceno, Hannah McKenzie Year: 2017 37 pages. A thesis presented to the Departments of Biology and Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2017 Close

• 35. [Article] Hydrodynamic and Water Quality Modeling of the Chehalis River in Washington

  The Chehalis River Basin is located in the southwest region of Washington and is over 125 miles long flowing through agricultural, residential, industrial, and forest land. Four major rivers, many smaller ...

  Citation × Citation Citation Abstract Copy Title: Hydrodynamic and Water Quality Modeling of the Chehalis River in Washington Author: Van Glubt, Sarah, Wells, Scott A., Berger, Chris J. Year: 2017 The Chehalis River Basin is located in the southwest region of Washington and is over 125 miles long flowing through agricultural, residential, industrial, and forest land. Four major rivers, many smaller creeks, five wastewater treatment plants, and groundwater discharge to the Chehalis River. Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia. As a result, construction of a flood-control dam in the upper basin has been proposed. One major concern of constructing a dam is the potentially severe impacts to fish health and habitat. The Chehalis River has routinely violated water quality standards for primarily temperature and dissolved oxygen. CE-QUAL-W2, a two-dimensional (longitudinal and vertical) hydrodynamic and water quality model, was used to simulate the Chehalis River, including free flowing river stretches and stratified (in summer) lake-like stretches. The goals of this research were to assess the flood retention structure’s impacts to water quality, as well as river responses to potential climate change scenarios. In order to use the model to achieve these goals, calibration to field data for flow, temperature, and water quality constituents was performed for the years 2013 and 2014. Once calibration was complete, model scenarios for future climate conditions and dam operating regimes were conducted. Future conditions showed predictions of warmer water temperatures and slight changes to water quality conditions on the river. As fish in the area prefer cooler water temperatures, this could pose a threat to fish health and habitat. Flood retention structures with the purpose of flood retention only (only operating during times of flooding) gave model predictions for daily maximum temperature higher than structures that employed flood retention and flow augmentation (operating during all times of the year). This suggested the management of flow passage or retention by the dam is important for water quality on the river. Title: Hydrodynamic and Water Quality Modeling of the Chehalis River in Washington Author: Van Glubt, Sarah, Wells, Scott A., Berger, Chris J. Year: 2017 The Chehalis River Basin is located in the southwest region of Washington and is over 125 miles long flowing through agricultural, residential, industrial, and forest land. Four major rivers, many smaller creeks, five wastewater treatment plants, and groundwater discharge to the Chehalis River. Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia. As a result, construction of a flood-control dam in the upper basin has been proposed. One major concern of constructing a dam is the potentially severe impacts to fish health and habitat. The Chehalis River has routinely violated water quality standards for primarily temperature and dissolved oxygen. CE-QUAL-W2, a two-dimensional (longitudinal and vertical) hydrodynamic and water quality model, was used to simulate the Chehalis River, including free flowing river stretches and stratified (in summer) lake-like stretches. The goals of this research were to assess the flood retention structure’s impacts to water quality, as well as river responses to potential climate change scenarios. In order to use the model to achieve these goals, calibration to field data for flow, temperature, and water quality constituents was performed for the years 2013 and 2014. Once calibration was complete, model scenarios for future climate conditions and dam operating regimes were conducted. Future conditions showed predictions of warmer water temperatures and slight changes to water quality conditions on the river. As fish in the area prefer cooler water temperatures, this could pose a threat to fish health and habitat. Flood retention structures with the purpose of flood retention only (only operating during times of flooding) gave model predictions for daily maximum temperature higher than structures that employed flood retention and flow augmentation (operating during all times of the year). This suggested the management of flow passage or retention by the dam is important for water quality on the river. Close

• 36. [Article] Effect of Oxygen Content on Thermal Stability of Grain Size for Nanocrystalline Fe10Cr and Fe14Cr4Hf Alloy Powders

  Low oxygen content powders of high purity elemental Fe, Cr and Hf were produced in a glove box by mechanically filing the solid materials. Fe10Cr and Fe14Cr4Hf nanocrystalline alloy powders were processed ...

  Citation × Citation Citation Abstract Copy Title: Effect of Oxygen Content on Thermal Stability of Grain Size for Nanocrystalline Fe10Cr and Fe14Cr4Hf Alloy Powders Author: Roodposhti, Peiman Shahbeigi, Saber, Mostafa, Koch, Carl, Scattergood, Ronald Year: 2017 Low oxygen content powders of high purity elemental Fe, Cr and Hf were produced in a glove box by mechanically filing the solid materials. Fe10Cr and Fe14Cr4Hf nanocrystalline alloy powders were processed using these elemental powders in conjunction with SPEX ball milling. The grain-size stability of the nanocrystalline alloy powders was investigated for selected annealing temperatures. High temperature stabilization can be achieved by Zener pinning (kinetic mechanism) or segregation of Hf to grain boundaries (thermodynamic mechanism). Solute drag mechanisms can be effective at lower annealing temperatures. Recent regular solution models developed by the authors predict that Hf would facilitate thermodynamic grain-size stabilization in Fe14Cr4Hf alloys at high temperatures. However Hf-base reactions such as intermetallic phase or oxide formation can favor kinetic stabilization and this can dominate over a contribution from thermodynamic stabilization. In contrast, grain-size stabilization in Fe10Cr alloy would be a result of solute drag by the Cr solutes at lower temperatures. The results from previous investigations on Fe10Cr and Fe14Cr4Hf nanocrystalline alloys were (unknowingly at the time) influenced by the fact that the commercially available high purity elemental powders used for SPEX ball mill processing contained significant amounts of oxygen impurity. The results obtained in this investigation using identical processing methods with low oxygen content powders for synthesizing the alloys provide further insight into their stabilization mechanisms. Title: Effect of Oxygen Content on Thermal Stability of Grain Size for Nanocrystalline Fe10Cr and Fe14Cr4Hf Alloy Powders Author: Roodposhti, Peiman Shahbeigi, Saber, Mostafa, Koch, Carl, Scattergood, Ronald Year: 2017 Low oxygen content powders of high purity elemental Fe, Cr and Hf were produced in a glove box by mechanically filing the solid materials. Fe10Cr and Fe14Cr4Hf nanocrystalline alloy powders were processed using these elemental powders in conjunction with SPEX ball milling. The grain-size stability of the nanocrystalline alloy powders was investigated for selected annealing temperatures. High temperature stabilization can be achieved by Zener pinning (kinetic mechanism) or segregation of Hf to grain boundaries (thermodynamic mechanism). Solute drag mechanisms can be effective at lower annealing temperatures. Recent regular solution models developed by the authors predict that Hf would facilitate thermodynamic grain-size stabilization in Fe14Cr4Hf alloys at high temperatures. However Hf-base reactions such as intermetallic phase or oxide formation can favor kinetic stabilization and this can dominate over a contribution from thermodynamic stabilization. In contrast, grain-size stabilization in Fe10Cr alloy would be a result of solute drag by the Cr solutes at lower temperatures. The results from previous investigations on Fe10Cr and Fe14Cr4Hf nanocrystalline alloys were (unknowingly at the time) influenced by the fact that the commercially available high purity elemental powders used for SPEX ball mill processing contained significant amounts of oxygen impurity. The results obtained in this investigation using identical processing methods with low oxygen content powders for synthesizing the alloys provide further insight into their stabilization mechanisms. Close

• 37. [Article] Static Fatigue Lifetime of Optical Fibers Assessed Using Boltzmann-Arrhenius-Zhurkov (BAZ) Model

  The recently suggested probabilistic design-for-reliability (PDfR) concept and particularly its physically meaningful and flexible Boltzmann–Arrhenius–Zhurkov (BAZ) model, can be effectively employed as ...

  Citation × Citation Citation Abstract Copy Title: Static Fatigue Lifetime of Optical Fibers Assessed Using Boltzmann-Arrhenius-Zhurkov (BAZ) Model Author: Suhir, Ephraim Year: 2017 The recently suggested probabilistic design-for-reliability (PDfR) concept and particularly its physically meaningful and flexible Boltzmann–Arrhenius–Zhurkov (BAZ) model, can be effectively employed as an attractive replacement of the widely used today purely empirical and physically unsubstantiated power law relationship for assessing the static fatigue (delayed fracture) lifetime of optical silica fibers. In this analysis the BAZ model is employed to estimate the static fatigue lifetime of an optical silica fiber under the combined action of tensile loading and an elevated temperature. The PDfR concept has its experimental basis in the highly-focused and highly-cost-effective failure-oriented accelerated testing (FOAT). Accordingly, it is shown how the PDfR concept, BAZ model and FOAT data can be effectively used, when there is a need to assess the long-term tensile strength (static fatigue life) of a coated optical fiber subjected to the combined action of tensile loading and elevated temperature. Although the role of elevated humidity might be insignificant owing to the elevated temperature conditions, this role can be accounted for, if there is a need for that, as well, by using multi-parametric BAZ model. Since the principle of superposition does not work in reliability engineering, all the three stressors, namely, the elevated temperature, tensile stress and relative humidity, should be applied concurrently to the specimen under test, and their coupling, if any, should and could be considered by the FOAT based on the BAZ model. The numerical example is carried out, however, for the case when only the elevated temperature and tensile stress are applied. The results of the analysis can be employed in the design and testing of optical silica fibers. Title: Static Fatigue Lifetime of Optical Fibers Assessed Using Boltzmann-Arrhenius-Zhurkov (BAZ) Model Author: Suhir, Ephraim Year: 2017 The recently suggested probabilistic design-for-reliability (PDfR) concept and particularly its physically meaningful and flexible Boltzmann–Arrhenius–Zhurkov (BAZ) model, can be effectively employed as an attractive replacement of the widely used today purely empirical and physically unsubstantiated power law relationship for assessing the static fatigue (delayed fracture) lifetime of optical silica fibers. In this analysis the BAZ model is employed to estimate the static fatigue lifetime of an optical silica fiber under the combined action of tensile loading and an elevated temperature. The PDfR concept has its experimental basis in the highly-focused and highly-cost-effective failure-oriented accelerated testing (FOAT). Accordingly, it is shown how the PDfR concept, BAZ model and FOAT data can be effectively used, when there is a need to assess the long-term tensile strength (static fatigue life) of a coated optical fiber subjected to the combined action of tensile loading and elevated temperature. Although the role of elevated humidity might be insignificant owing to the elevated temperature conditions, this role can be accounted for, if there is a need for that, as well, by using multi-parametric BAZ model. Since the principle of superposition does not work in reliability engineering, all the three stressors, namely, the elevated temperature, tensile stress and relative humidity, should be applied concurrently to the specimen under test, and their coupling, if any, should and could be considered by the FOAT based on the BAZ model. The numerical example is carried out, however, for the case when only the elevated temperature and tensile stress are applied. The results of the analysis can be employed in the design and testing of optical silica fibers. Close

• 38. [Article] Development of a Steady-State River Hydrodynamic and Temperature Model Based on CE-QUAL-W2

  CE-QUAL-W2 is a 2-D hydrodynamic and water quality model that has been applied to reservoirs, lakes, river systems, and estuaries throughout the world. However, when this model is applied for shallow systems, ...

  Citation × Citation Citation Abstract Copy Title: Development of a Steady-State River Hydrodynamic and Temperature Model Based on CE-QUAL-W2 Author: Xu, Wenwei Year: 2014 CE-QUAL-W2 is a 2-D hydrodynamic and water quality model that has been applied to reservoirs, lakes, river systems, and estuaries throughout the world. However, when this model is applied for shallow systems, this model requires a long calculation time to maintain numerical stability, compared to applications of reservoirs or deeper river systems. To solve this problem, a new hydrodynamic and temperature model was built based on the framework of CE-QUAL-W2 but that allows for steady-state hydrodynamic computations. By calculating the hydrodynamics at steady-state, the time step for stability is relaxed and simulations can proceed at much higher time steps. The rest of the model framework is still used for water quality state variables, in this case, temperature. The algorithm used for computing the water surface elevation is Manning's equation. This thesis study is one part of the Willamette Water 2100 project (Santelmann et al., 2012), which examines hydrological, ecological, and human factors affecting water scarcity in the Willamette River Basin. This study included three stages: (1) Convert six existing CE-QUAL-W2 V3.1 models into a newer version: CE-QUAL-W2 V3.7. (2) Develop the steady-state model code in FORTRAN. (3) Test the steady-state model on three river systems in the Willamette River Basin at Year 2001 and 2002. The result proved that the steady-state model could reduce the computing time by 90% for river applications, while predicting dynamic river temperature with high accuracy at a two-minute time scale. This new model will be employed to simulate the future of the Willamette River System at a decadal or centennial timescales, addressing river temperature concerns and fish habitat issues. Title: Development of a Steady-State River Hydrodynamic and Temperature Model Based on CE-QUAL-W2 Author: Xu, Wenwei Year: 2014 CE-QUAL-W2 is a 2-D hydrodynamic and water quality model that has been applied to reservoirs, lakes, river systems, and estuaries throughout the world. However, when this model is applied for shallow systems, this model requires a long calculation time to maintain numerical stability, compared to applications of reservoirs or deeper river systems. To solve this problem, a new hydrodynamic and temperature model was built based on the framework of CE-QUAL-W2 but that allows for steady-state hydrodynamic computations. By calculating the hydrodynamics at steady-state, the time step for stability is relaxed and simulations can proceed at much higher time steps. The rest of the model framework is still used for water quality state variables, in this case, temperature. The algorithm used for computing the water surface elevation is Manning's equation. This thesis study is one part of the Willamette Water 2100 project (Santelmann et al., 2012), which examines hydrological, ecological, and human factors affecting water scarcity in the Willamette River Basin. This study included three stages: (1) Convert six existing CE-QUAL-W2 V3.1 models into a newer version: CE-QUAL-W2 V3.7. (2) Develop the steady-state model code in FORTRAN. (3) Test the steady-state model on three river systems in the Willamette River Basin at Year 2001 and 2002. The result proved that the steady-state model could reduce the computing time by 90% for river applications, while predicting dynamic river temperature with high accuracy at a two-minute time scale. This new model will be employed to simulate the future of the Willamette River System at a decadal or centennial timescales, addressing river temperature concerns and fish habitat issues. Close

• 39. [Article] Using Spatially Explicit Indicators to Investigate Watershed Characteristics and stream temperature relationships

  We generate a series of novel indicators of spatially explicit watershed permeability and runoff characteristics to examine the relationship between land cover and water temperature parameters in a rapidly ...

  Citation × Citation Citation Abstract Copy Title: Using Spatially Explicit Indicators to Investigate Watershed Characteristics and stream temperature relationships Author: Grabowski, Zbigniew J., Watson, Eric, Chang, Heejun Year: 2016 We generate a series of novel indicators of spatially explicit watershed permeability and runoff characteristics to examine the relationship between land cover and water temperature parameters in a rapidly urbanizing watershed. Our framework provides a readily adaptable method to examine the thermal sensitivity of streams based upon the underlying geomorphological and surface characteristics of drainage basins. Using four model groups each using a different landscape characteristic weighting scheme (Model Group 1: areal averages; Model Group 2: inverse distance by total flow length; Model Group 3: overland distance to stream network and distance squared; Model Group 4: proportional flow accumulation), we examined the predictive capacity of 19 variables, including combinations of simplified land cover, elevation, slope, and flow accumulation, on five stream thermal properties: seven day moving average of daily minimum and maximum, seasonal mean temperature, a novel metric of thermal 'flashiness', and total days with maximum temperature exceeding 17.8°C. We find that the use of spatially explicit landscape indicators combining watershed processes improves the performance of regressions for predicting a number of ecologically relevant stream temperature variables. Improved indicators of watershed condition lend themselves for rapid investigation of the relationship between stream thermal conditions and landscape characteristics in watersheds modified by human land uses, ultimately providing a more hydrologically meaningful indicator for the impacts of landscape change. Title: Using Spatially Explicit Indicators to Investigate Watershed Characteristics and stream temperature relationships Author: Grabowski, Zbigniew J., Watson, Eric, Chang, Heejun Year: 2016 We generate a series of novel indicators of spatially explicit watershed permeability and runoff characteristics to examine the relationship between land cover and water temperature parameters in a rapidly urbanizing watershed. Our framework provides a readily adaptable method to examine the thermal sensitivity of streams based upon the underlying geomorphological and surface characteristics of drainage basins. Using four model groups each using a different landscape characteristic weighting scheme (Model Group 1: areal averages; Model Group 2: inverse distance by total flow length; Model Group 3: overland distance to stream network and distance squared; Model Group 4: proportional flow accumulation), we examined the predictive capacity of 19 variables, including combinations of simplified land cover, elevation, slope, and flow accumulation, on five stream thermal properties: seven day moving average of daily minimum and maximum, seasonal mean temperature, a novel metric of thermal 'flashiness', and total days with maximum temperature exceeding 17.8°C. We find that the use of spatially explicit landscape indicators combining watershed processes improves the performance of regressions for predicting a number of ecologically relevant stream temperature variables. Improved indicators of watershed condition lend themselves for rapid investigation of the relationship between stream thermal conditions and landscape characteristics in watersheds modified by human land uses, ultimately providing a more hydrologically meaningful indicator for the impacts of landscape change. Close

• 40. [Article] Power core (PC) Embedding a Plurality of IC Devices and Sandwiched Between Two Dissimilar Insulated Metal Substrates (IMS’): Predicted Thermal Stresses

  Power core (PC) sandwiched between two insulated metal substrates (IMS) and embedding active and passive integrated circuit (IC) devices is currently viewed as an attractive advanced packaging option having ...

  Citation × Citation Citation Abstract Copy Title: Power core (PC) Embedding a Plurality of IC Devices and Sandwiched Between Two Dissimilar Insulated Metal Substrates (IMS’): Predicted Thermal Stresses Author: Suhir, Ephraim, Nicolics, Johann Year: 2016 Power core (PC) sandwiched between two insulated metal substrates (IMS) and embedding active and passive integrated circuit (IC) devices is currently viewed as an attractive advanced packaging option having a strong potential in the automotive industry and beyond. A natural reliability concern, however, is the level of the thermally induced stresses in a tri-material assembly of the type in question. Accordingly, an analytical (mathematical) stress model is developed for the evaluation of these stresses. The stresses include normal stresses acting in the cross-sections of the assembly components, and the interfacial shearing and peeling stresses acting at the interfaces of these components and at the interfaces of the embedded IC devices. The model can be helpful in the stress-analysis and physical design of the assemblies, in which the PC is sandwiched between two IMS’. It can be used also in other areas of engineering, where tri-material assemblies comprised of dissimilar materials and subjected to the change in temperature are employed. The general concepts are illustrated by a detailed numerical example. The analysis is an extension of the study carried out earlier for a bow-free assembly. It is noteworthy that although the calculations are carried out for the case when the assembly is cooled down from an elevated temperature to a low temperature, since a linear approach is used and the stresses are proportional to the change in temperature, whatever its sign or the magnitude is, the developed model is equally applicable to any change in temperature. Title: Power core (PC) Embedding a Plurality of IC Devices and Sandwiched Between Two Dissimilar Insulated Metal Substrates (IMS’): Predicted Thermal Stresses Author: Suhir, Ephraim, Nicolics, Johann Year: 2016 Power core (PC) sandwiched between two insulated metal substrates (IMS) and embedding active and passive integrated circuit (IC) devices is currently viewed as an attractive advanced packaging option having a strong potential in the automotive industry and beyond. A natural reliability concern, however, is the level of the thermally induced stresses in a tri-material assembly of the type in question. Accordingly, an analytical (mathematical) stress model is developed for the evaluation of these stresses. The stresses include normal stresses acting in the cross-sections of the assembly components, and the interfacial shearing and peeling stresses acting at the interfaces of these components and at the interfaces of the embedded IC devices. The model can be helpful in the stress-analysis and physical design of the assemblies, in which the PC is sandwiched between two IMS’. It can be used also in other areas of engineering, where tri-material assemblies comprised of dissimilar materials and subjected to the change in temperature are employed. The general concepts are illustrated by a detailed numerical example. The analysis is an extension of the study carried out earlier for a bow-free assembly. It is noteworthy that although the calculations are carried out for the case when the assembly is cooled down from an elevated temperature to a low temperature, since a linear approach is used and the stresses are proportional to the change in temperature, whatever its sign or the magnitude is, the developed model is equally applicable to any change in temperature. Close

• 41. [Article] Understanding the Joint Behavior of Temperature and Precipitation for Climate Change Impact Studies

  The multiple downscaled-scenario products allow us to assess the uncertainty of the variations of precipitation and temperature in the current and future periods. Probabilistic assessments of both climatic ...

  Citation × Citation Citation Abstract Copy Title: Understanding the Joint Behavior of Temperature and Precipitation for Climate Change Impact Studies Author: Rana, Arun, Moradkhani, Hamid, Qin, Yueyue Year: 2016 The multiple downscaled-scenario products allow us to assess the uncertainty of the variations of precipitation and temperature in the current and future periods. Probabilistic assessments of both climatic variables help better understand the interdependence of the two, and thus in-turn help in assessing the future with confidence. In the present study, we use ensemble of statistically downscaled precipitation and temperature from various models. The dataset used is multi-model ensemble of 10 Global Climate Models (GCMs) downscaled product from CMIP5 daily dataset, using the Bias Correction and Spatial Downscaling (BCSD) technique, generated at Portland State University. The multi-model ensemble of both precipitation and temperature is evaluated for dry and wet periods for 10 sub-basins across Columbia River Basin (CRB). Thereafter, Copula is applied to establish the joint distribution of two variables on multi-model ensemble data. The joint distribution is then used to estimate the change in trends of said variables in future, along with estimation of the probabilities of the given change. The joint distribution trends varies, but certainly positive, for dry and wet periods in sub-basins of CRB. Dry season, generally, is indicating a higher positive change in precipitation than temperature (as compared to historical) across sub-basins with wet season inferring otherwise. Probabilities of changes in future, as estimated from the joint distribution indicate varied degrees and forms during dry season whereas the wet season is rather constant across all the sub-basins. Title: Understanding the Joint Behavior of Temperature and Precipitation for Climate Change Impact Studies Author: Rana, Arun, Moradkhani, Hamid, Qin, Yueyue Year: 2016 The multiple downscaled-scenario products allow us to assess the uncertainty of the variations of precipitation and temperature in the current and future periods. Probabilistic assessments of both climatic variables help better understand the interdependence of the two, and thus in-turn help in assessing the future with confidence. In the present study, we use ensemble of statistically downscaled precipitation and temperature from various models. The dataset used is multi-model ensemble of 10 Global Climate Models (GCMs) downscaled product from CMIP5 daily dataset, using the Bias Correction and Spatial Downscaling (BCSD) technique, generated at Portland State University. The multi-model ensemble of both precipitation and temperature is evaluated for dry and wet periods for 10 sub-basins across Columbia River Basin (CRB). Thereafter, Copula is applied to establish the joint distribution of two variables on multi-model ensemble data. The joint distribution is then used to estimate the change in trends of said variables in future, along with estimation of the probabilities of the given change. The joint distribution trends varies, but certainly positive, for dry and wet periods in sub-basins of CRB. Dry season, generally, is indicating a higher positive change in precipitation than temperature (as compared to historical) across sub-basins with wet season inferring otherwise. Probabilities of changes in future, as estimated from the joint distribution indicate varied degrees and forms during dry season whereas the wet season is rather constant across all the sub-basins. Close

• 42. [Article] Interactive Physiological Responses of Nile Tilapia to Salinity- and Temperature-induced Stress: Quantifying the Regulation of Apoptosis and Cell Cycle Arrest in Oreochromis Niloticus

  Nile tilapia provide an ideal model to study the accumulation of climate change-induced stressors due to their habitat in tropical freshwater systems that are susceptible to salt water invasion and temperature ...

  Citation × Citation Citation Abstract Copy Title: Interactive Physiological Responses of Nile Tilapia to Salinity- and Temperature-induced Stress: Quantifying the Regulation of Apoptosis and Cell Cycle Arrest in Oreochromis Niloticus Author: McGuire, Charlee Year: 2017 Nile tilapia provide an ideal model to study the accumulation of climate change-induced stressors due to their habitat in tropical freshwater systems that are susceptible to salt water invasion and temperature fluctuation due to sea level rise. This study investigates the physiological responses of Nile tilapia to salinity- and temperature-induced stress to identify the interactive effects of simultaneous stressors on the cell cycle. Proteins indicative of cell cycle activity and arrest were quantified in the tissues of Nile tilapia exposed to various environmental conditions varying by temperature and salinity. Dot Blotting was utilized to measure Gadd45 while Western Blotting was used to confirm the identity of the protein. Results from previous investigations in the Buckley lab were also utilized to compare the expression patterns of Gadd45 to relevant cell activity proteins p53 and PCNA. Of the three proteins under scrutiny, a significant change in expression of p53 was observed for the interaction of salinity- and temperature- induced stress, while full strength saltwater treatment alone was found to have a significant impact on the expression of p53, Gadd45 and PCNA. These findings can be used in collaboration with existing studies to describe the coordination of apoptotic pathways in Nile tilapia and other non-mammalian species, as well as to create policy on how to conserve this important species effectively both in the wild and in fisheries for aquaculture, commercial and public health initiatives in response to global climate change. Title: Interactive Physiological Responses of Nile Tilapia to Salinity- and Temperature-induced Stress: Quantifying the Regulation of Apoptosis and Cell Cycle Arrest in Oreochromis Niloticus Author: McGuire, Charlee Year: 2017 Nile tilapia provide an ideal model to study the accumulation of climate change-induced stressors due to their habitat in tropical freshwater systems that are susceptible to salt water invasion and temperature fluctuation due to sea level rise. This study investigates the physiological responses of Nile tilapia to salinity- and temperature-induced stress to identify the interactive effects of simultaneous stressors on the cell cycle. Proteins indicative of cell cycle activity and arrest were quantified in the tissues of Nile tilapia exposed to various environmental conditions varying by temperature and salinity. Dot Blotting was utilized to measure Gadd45 while Western Blotting was used to confirm the identity of the protein. Results from previous investigations in the Buckley lab were also utilized to compare the expression patterns of Gadd45 to relevant cell activity proteins p53 and PCNA. Of the three proteins under scrutiny, a significant change in expression of p53 was observed for the interaction of salinity- and temperature- induced stress, while full strength saltwater treatment alone was found to have a significant impact on the expression of p53, Gadd45 and PCNA. These findings can be used in collaboration with existing studies to describe the coordination of apoptotic pathways in Nile tilapia and other non-mammalian species, as well as to create policy on how to conserve this important species effectively both in the wild and in fisheries for aquaculture, commercial and public health initiatives in response to global climate change. Close

• 43. [Article] Utilizing Humidity and Temperature Data to Advance Monitoring and Prediction of Meteorological Drought

  The fraction of land area over the Continental United States experiencing extreme hot and dry conditions has been increasing over the past several decades, consistent with expectation from anthropogenic ...

  Citation × Citation Citation Abstract Copy Title: Utilizing Humidity and Temperature Data to Advance Monitoring and Prediction of Meteorological Drought Author: Behrangi, Ali, Loikith, Paul C., Fetzer, Eric J., Nguyen, Hai M., Granger, Stephanie L. Year: 2015 The fraction of land area over the Continental United States experiencing extreme hot and dry conditions has been increasing over the past several decades, consistent with expectation from anthropogenic climate change. A clear concurrent change in precipitation, however, has not been confirmed. Vapor pressure deficit (VPD), combining temperature and humidity, is utilized here as an indicator of the background atmospheric conditions associated with meteorological drought. Furthermore, atmospheric conditions associated with warm season drought events are assessed by partitioning associated VPD anomalies into the temperature and humidity components. This approach suggests that the concurrence of anomalously high temperature and low humidity was an important driver of the rapid development and evolution of the exceptionally severe 2011 Texas and the 2012 Great Plains droughts. By classification of a decade of extreme drought events and tracking them back in time, it was found that near surface atmospheric temperature and humidity add essential information to the commonly used precipitation-based drought indicators and can advance efforts to determine the timing of drought onset and its severity. Title: Utilizing Humidity and Temperature Data to Advance Monitoring and Prediction of Meteorological Drought Author: Behrangi, Ali, Loikith, Paul C., Fetzer, Eric J., Nguyen, Hai M., Granger, Stephanie L. Year: 2015 The fraction of land area over the Continental United States experiencing extreme hot and dry conditions has been increasing over the past several decades, consistent with expectation from anthropogenic climate change. A clear concurrent change in precipitation, however, has not been confirmed. Vapor pressure deficit (VPD), combining temperature and humidity, is utilized here as an indicator of the background atmospheric conditions associated with meteorological drought. Furthermore, atmospheric conditions associated with warm season drought events are assessed by partitioning associated VPD anomalies into the temperature and humidity components. This approach suggests that the concurrence of anomalously high temperature and low humidity was an important driver of the rapid development and evolution of the exceptionally severe 2011 Texas and the 2012 Great Plains droughts. By classification of a decade of extreme drought events and tracking them back in time, it was found that near surface atmospheric temperature and humidity add essential information to the commonly used precipitation-based drought indicators and can advance efforts to determine the timing of drought onset and its severity. Close

• 44. [Article] Micrometeorological Simulations to Predict the Impacts of Heat Mitigation Strategies on Pedestrian Thermal Comfort in a Los Angeles Neighborhood

  The urban heat island impacts the thermal comfort of pedestrians in cities. In this paper, the effects of four heat mitigation strategies on micrometeorology and the thermal comfort of pedestrians were ...

  Citation × Citation Citation Abstract Copy Title: Micrometeorological Simulations to Predict the Impacts of Heat Mitigation Strategies on Pedestrian Thermal Comfort in a Los Angeles Neighborhood Author: Taleghani, Mohammad, Sailor, David J., Ban-Weiss, George A. Year: 2016 The urban heat island impacts the thermal comfort of pedestrians in cities. In this paper, the effects of four heat mitigation strategies on micrometeorology and the thermal comfort of pedestrians were simulated for a neighborhood in eastern Los Angeles County. The strategies investigated include solar reflective ‘cool roofs’, vegetative ‘green roofs’, solar reflective ‘cool pavements’, and increased streetlevel trees. Aseries of micrometeorological simulations for an extreme heat day were carried out assuming widespread adoption of each mitigation strategy. Comparing each simulation to the control simulation assuming current land cover for the neighborhood showed that additional street-trees and cool pavements reduced 1.5mair temperature, while cool and green roofs mostly provided cooling at heights above pedestrian level. However, cool pavements increased reflected sunlight from the ground to pedestrians at a set of unshaded receptor locations. This reflected radiation intensified the mean radiant temperature and consequently increased physiological equivalent temperature (PET) by 2.2 °Cduring the day, reducing the thermal comfort of pedestrians. At another set of receptor locations that were on average 5mfrom roadways and underneath preexisting tree cover, cool pavements caused significant reductions in surface air temperatures and small changes in mean radiant temperature during the day, leading to decreases in PET of 1.1 °C, and consequent improvements in thermal comfort. For improving thermal comfort of pedestrians during the afternoon in unshaded locations, adding street trees was found to be the most effective strategy. However, afternoon thermal comfort improvements in already shaded locations adjacent to streets were most significant for cool pavements. Green and cool roofs showed the lowest impact on the thermal comfort of pedestrians since they modify the energy balance at roof level, above the height of pedestrians. Title: Micrometeorological Simulations to Predict the Impacts of Heat Mitigation Strategies on Pedestrian Thermal Comfort in a Los Angeles Neighborhood Author: Taleghani, Mohammad, Sailor, David J., Ban-Weiss, George A. Year: 2016 The urban heat island impacts the thermal comfort of pedestrians in cities. In this paper, the effects of four heat mitigation strategies on micrometeorology and the thermal comfort of pedestrians were simulated for a neighborhood in eastern Los Angeles County. The strategies investigated include solar reflective ‘cool roofs’, vegetative ‘green roofs’, solar reflective ‘cool pavements’, and increased streetlevel trees. Aseries of micrometeorological simulations for an extreme heat day were carried out assuming widespread adoption of each mitigation strategy. Comparing each simulation to the control simulation assuming current land cover for the neighborhood showed that additional street-trees and cool pavements reduced 1.5mair temperature, while cool and green roofs mostly provided cooling at heights above pedestrian level. However, cool pavements increased reflected sunlight from the ground to pedestrians at a set of unshaded receptor locations. This reflected radiation intensified the mean radiant temperature and consequently increased physiological equivalent temperature (PET) by 2.2 °Cduring the day, reducing the thermal comfort of pedestrians. At another set of receptor locations that were on average 5mfrom roadways and underneath preexisting tree cover, cool pavements caused significant reductions in surface air temperatures and small changes in mean radiant temperature during the day, leading to decreases in PET of 1.1 °C, and consequent improvements in thermal comfort. For improving thermal comfort of pedestrians during the afternoon in unshaded locations, adding street trees was found to be the most effective strategy. However, afternoon thermal comfort improvements in already shaded locations adjacent to streets were most significant for cool pavements. Green and cool roofs showed the lowest impact on the thermal comfort of pedestrians since they modify the energy balance at roof level, above the height of pedestrians. Close

• 45. [Article] A Statistical Investigation of Lower Columbia River Water Temperature, 1915-2003

  The Columbia River is home to anadromous salmon populations that migrate upriver every year to spawn. These fish require cool water temperatures (Tw) to survive. In recent years, high summer Tw in the ...

  Citation × Citation Citation Abstract Copy Title: A Statistical Investigation of Lower Columbia River Water Temperature, 1915-2003 Author: Overman, Corina Christina Mae Year: 2017 The Columbia River is home to anadromous salmon populations that migrate upriver every year to spawn. These fish require cool water temperatures (Tw) to survive. In recent years, high summer Tw in the Columbia River has caused increased mortality of salmon. Different possible explanations for increased Tw include climate change, deforestation, and decreased summertime streamflow (Q) due to dams. In this study, robust linear regression models of Tw based on air temperature (Ta) and Q were developed to examine the change in Tw over time. The data was separated into an historical period (1938-1956) and a modern period (1977-2003). Seasonal regression models were used for May through October (summer) and November through April (winter) for each period. Comparison of these models showed that Tw has become less sensitive to recent atmospheric heating and cooling. By contrast, analysis suggested that Tw has become more sensitive to variations in Q. Of the 1.5ºC increase in maximum summertime Tw, approximately 1.3ºC was due to dams and reservoir management based on changes in regression coefficients and average Q. A smaller, 0.2ºC change was estimated to be caused by increasing Ta since the mid-20th century. While average maximum Tw has increased, both the statistical model and data suggest that the variability in Tw from its climatological average has decreased, probably due to reservoir management. Title: A Statistical Investigation of Lower Columbia River Water Temperature, 1915-2003 Author: Overman, Corina Christina Mae Year: 2017 The Columbia River is home to anadromous salmon populations that migrate upriver every year to spawn. These fish require cool water temperatures (Tw) to survive. In recent years, high summer Tw in the Columbia River has caused increased mortality of salmon. Different possible explanations for increased Tw include climate change, deforestation, and decreased summertime streamflow (Q) due to dams. In this study, robust linear regression models of Tw based on air temperature (Ta) and Q were developed to examine the change in Tw over time. The data was separated into an historical period (1938-1956) and a modern period (1977-2003). Seasonal regression models were used for May through October (summer) and November through April (winter) for each period. Comparison of these models showed that Tw has become less sensitive to recent atmospheric heating and cooling. By contrast, analysis suggested that Tw has become more sensitive to variations in Q. Of the 1.5ºC increase in maximum summertime Tw, approximately 1.3ºC was due to dams and reservoir management based on changes in regression coefficients and average Q. A smaller, 0.2ºC change was estimated to be caused by increasing Ta since the mid-20th century. While average maximum Tw has increased, both the statistical model and data suggest that the variability in Tw from its climatological average has decreased, probably due to reservoir management. Close

• 46. [Article] 3D Numerical Temperature Model Development and Calibration for Lakes and Reservoirs: A Case Study

  A 3D hydrodynamic and temperature numerical model was developed and calibrated for Lake Chaplain, Washington, USA. The governing equations are the continuity equation, free surface equation, momentum equation, ...

  Citation × Citation Citation Abstract Copy Title: 3D Numerical Temperature Model Development and Calibration for Lakes and Reservoirs: A Case Study Author: Al-Zubaidi, Hussein A. M., Wells, Scott A. Year: 2017 A 3D hydrodynamic and temperature numerical model was developed and calibrated for Lake Chaplain, Washington, USA. The governing equations are the continuity equation, free surface equation, momentum equation, and conservation equation of transport. The model employs the semi-implicit finite difference scheme to solve the governing equations and higher order schemes (QUICK and Quickest) for mass and heat transport in contrast to simpler but more diffusive first order UPWIND scheme. A unique feature of the 3D numerical solution of the model free surface equation is that the solution uses a tri-diagonal matrix form rather than a more common pentadiagonal matrix. The surface heat exchange and turbulence structure were based on the CE-QUAL-W2 model. Comparisons in water surface levels and temperature vertical profiles between model predictions and data were performed using different advective transport schemes. The model matched data with good error statistics. Title: 3D Numerical Temperature Model Development and Calibration for Lakes and Reservoirs: A Case Study Author: Al-Zubaidi, Hussein A. M., Wells, Scott A. Year: 2017 A 3D hydrodynamic and temperature numerical model was developed and calibrated for Lake Chaplain, Washington, USA. The governing equations are the continuity equation, free surface equation, momentum equation, and conservation equation of transport. The model employs the semi-implicit finite difference scheme to solve the governing equations and higher order schemes (QUICK and Quickest) for mass and heat transport in contrast to simpler but more diffusive first order UPWIND scheme. A unique feature of the 3D numerical solution of the model free surface equation is that the solution uses a tri-diagonal matrix form rather than a more common pentadiagonal matrix. The surface heat exchange and turbulence structure were based on the CE-QUAL-W2 model. Comparisons in water surface levels and temperature vertical profiles between model predictions and data were performed using different advective transport schemes. The model matched data with good error statistics. Close

• 47. [Article] Olivine Crystallization Depths within Kilauea's Lower East Rift Zone: The Use of Rehomogenized Melt Inclusions to Interpret Magma Transport, Storage, and Energetic Fountaining

  H2O and CO2 concentrations in olivine-hosted melt inclusions, assuming vapor saturation at the time of trapping, can be used to estimate crystallization depths for the olivine host. Estimating the true ...

  Citation × Citation Citation Abstract Copy Title: Olivine Crystallization Depths within Kilauea's Lower East Rift Zone: The Use of Rehomogenized Melt Inclusions to Interpret Magma Transport, Storage, and Energetic Fountaining Author: Tuohy, Robin Year: 2014 H2O and CO2 concentrations in olivine-hosted melt inclusions, assuming vapor saturation at the time of trapping, can be used to estimate crystallization depths for the olivine host. Estimating the true CO2 in melt inclusions is difficult, as much is lost to shrinkage bubbles, which form upon post-entrapment cooling and crystallization. Reheating olivine to temperatures above the melt inclusion trapping temperature and then quenching rapidly can restore CO2 to the glass because the CO2 in the bubble redissolves at high temperature. Previous work has established that olivine crystallization for the1959 Kilauea Iki eruption took place in the shallow summit reservoir, but crystallization depths have not been established for the rift extension of the eruption, at Kapoho. The new data presented here suggest that the most primitive Kilauea Iki component bypassed the summit reservoir for the east rift zone prior to the start of the eruption and was later erupted at Kapoho. Title: Olivine Crystallization Depths within Kilauea's Lower East Rift Zone: The Use of Rehomogenized Melt Inclusions to Interpret Magma Transport, Storage, and Energetic Fountaining Author: Tuohy, Robin Year: 2014 H2O and CO2 concentrations in olivine-hosted melt inclusions, assuming vapor saturation at the time of trapping, can be used to estimate crystallization depths for the olivine host. Estimating the true CO2 in melt inclusions is difficult, as much is lost to shrinkage bubbles, which form upon post-entrapment cooling and crystallization. Reheating olivine to temperatures above the melt inclusion trapping temperature and then quenching rapidly can restore CO2 to the glass because the CO2 in the bubble redissolves at high temperature. Previous work has established that olivine crystallization for the1959 Kilauea Iki eruption took place in the shallow summit reservoir, but crystallization depths have not been established for the rift extension of the eruption, at Kapoho. The new data presented here suggest that the most primitive Kilauea Iki component bypassed the summit reservoir for the east rift zone prior to the start of the eruption and was later erupted at Kapoho. Close

• 48. [Article] The Geography of Glaciers and Perennial Snowfields in the American West

  A comprehensive mid-20th century inventory of glaciers and perennial snowfields (G&PS) was compiled for the American West, west of the 100° meridian. The inventory was derived from U.S. Geological Survey ...

  Citation × Citation Citation Abstract Copy Title: The Geography of Glaciers and Perennial Snowfields in the American West Author: Fountain, Andrew G., Glenn, Bryce, Basagic, Hassan J. Year: 2017 A comprehensive mid-20th century inventory of glaciers and perennial snowfields (G&PS) was compiled for the American West, west of the 100° meridian. The inventory was derived from U.S. Geological Survey 1:24,000 topographic maps based on aerial photographs acquired during 35 years, 1955–1990, of which the first 20 years or more was a cool period with little glacier change. The mapped features were filtered for those greater than 0.01 km2. Results show that 5036 G&PS (672 km2, 14 km3) populate eight states, of which about 1276 (554 km2, 12 km3) are glaciers. Uncertainty is estimated at ±9% for area and ±20% for volume. Two populations of G&PS were identified based on air temperature and precipitation. The larger is found in a maritime climate of the Pacific Northwest, characterized by warm winter air temperatures and high winter precipitation (~2100 mm). The other population is continental in climate, characterized by cold winter air temperatures, relatively low winter precipitation (~880 mm), and located at higher elevations elsewhere. The G&PS in the Pacific Northwest, especially in the Olympic Mountains, are particularly vulnerable to warming winter air temperatures that will change the phase of winter precipitation from snow to rain, further accelerating glacier shrinkage in the future. Comparison with a recent inventory suggests that the total G&PS area in the American West may have decreased by as much as 39% since the mid-20th century. Title: The Geography of Glaciers and Perennial Snowfields in the American West Author: Fountain, Andrew G., Glenn, Bryce, Basagic, Hassan J. Year: 2017 A comprehensive mid-20th century inventory of glaciers and perennial snowfields (G&PS) was compiled for the American West, west of the 100° meridian. The inventory was derived from U.S. Geological Survey 1:24,000 topographic maps based on aerial photographs acquired during 35 years, 1955–1990, of which the first 20 years or more was a cool period with little glacier change. The mapped features were filtered for those greater than 0.01 km2. Results show that 5036 G&PS (672 km2, 14 km3) populate eight states, of which about 1276 (554 km2, 12 km3) are glaciers. Uncertainty is estimated at ±9% for area and ±20% for volume. Two populations of G&PS were identified based on air temperature and precipitation. The larger is found in a maritime climate of the Pacific Northwest, characterized by warm winter air temperatures and high winter precipitation (~2100 mm). The other population is continental in climate, characterized by cold winter air temperatures, relatively low winter precipitation (~880 mm), and located at higher elevations elsewhere. The G&PS in the Pacific Northwest, especially in the Olympic Mountains, are particularly vulnerable to warming winter air temperatures that will change the phase of winter precipitation from snow to rain, further accelerating glacier shrinkage in the future. Comparison with a recent inventory suggests that the total G&PS area in the American West may have decreased by as much as 39% since the mid-20th century. Close

• 49. [Article] A Study of Microwave curing of Underfill using Open and Closed microwave ovens

  As the demand for microprocessors is increasing with more and more consumers using integrated circuits in their daily life, the demand on the industry is increasing to ramp up production. In order to speed ...

  Citation × Citation Citation Abstract Copy Title: A Study of Microwave curing of Underfill using Open and Closed microwave ovens Author: Thakare, Aditya Year: 2015 As the demand for microprocessors is increasing with more and more consumers using integrated circuits in their daily life, the demand on the industry is increasing to ramp up production. In order to speed up the manufacturing processes, new and novel approaches are trying to change certain aspects of it. Microwaves have been tried as an alternative to conventional ovens in the curing of the polymers used as underfills and encapsulants in integrated circuits packages. Microwaves however being electromagnetic waves have non uniform energy distribution in different settings, causing burning or incomplete cure of polymers. In this study, we compare the two main types of microwaves proposed to perform the task of curing the polymers. To limit the study and obtain comparable results, both microwaves were limited to propagate in a single mode, TE10. The first is a closed microwave cavity using air as the propagation medium, and the second is an open microwave oven with a PTFE cavity that uses an evanescent field to provide energy. The open air cavity was studied with different orientations of a substrate placed inside it so as to find the best case scenario in the curing process. This scenario was then compared with the best case scenario found for a sample cured in an evanescent field. This comparison yielded results showing an advantage of the open microwave in maximum field present, thus leading to higher localized energy absorption and temperatures in the substrate, however this case also lead to a higher temperature gradient. The substrate cured in the closed microwave has a lower temperature gradient, but also a lower maximum field which leads to slower cure. In the TE10 mode therefore, a closed microwave has an overall advantage as the heating process is only slightly slower than that of an open cavity, but the temperature gradient in this case is significantly lower. Title: A Study of Microwave curing of Underfill using Open and Closed microwave ovens Author: Thakare, Aditya Year: 2015 As the demand for microprocessors is increasing with more and more consumers using integrated circuits in their daily life, the demand on the industry is increasing to ramp up production. In order to speed up the manufacturing processes, new and novel approaches are trying to change certain aspects of it. Microwaves have been tried as an alternative to conventional ovens in the curing of the polymers used as underfills and encapsulants in integrated circuits packages. Microwaves however being electromagnetic waves have non uniform energy distribution in different settings, causing burning or incomplete cure of polymers. In this study, we compare the two main types of microwaves proposed to perform the task of curing the polymers. To limit the study and obtain comparable results, both microwaves were limited to propagate in a single mode, TE10. The first is a closed microwave cavity using air as the propagation medium, and the second is an open microwave oven with a PTFE cavity that uses an evanescent field to provide energy. The open air cavity was studied with different orientations of a substrate placed inside it so as to find the best case scenario in the curing process. This scenario was then compared with the best case scenario found for a sample cured in an evanescent field. This comparison yielded results showing an advantage of the open microwave in maximum field present, thus leading to higher localized energy absorption and temperatures in the substrate, however this case also lead to a higher temperature gradient. The substrate cured in the closed microwave has a lower temperature gradient, but also a lower maximum field which leads to slower cure. In the TE10 mode therefore, a closed microwave has an overall advantage as the heating process is only slightly slower than that of an open cavity, but the temperature gradient in this case is significantly lower. Close

• 50. [Article] Nanosilver Rainbow: A Rapid and Facile Method to Tune Different Colours of Nanosilver Through the Controlled Synthesis of Stable Spherical Silver Nanoparticles

  A rapid and simple one-pot reaction to synthesize stable, spherically shaped silver nanoparticles (AgNps) of different sizes producing distinct optical properties in aqueous solution at ambient temperature ...

  Citation × Citation Citation Abstract Copy Title: Nanosilver Rainbow: A Rapid and Facile Method to Tune Different Colours of Nanosilver Through the Controlled Synthesis of Stable Spherical Silver Nanoparticles Author: Mendis, Pramujitha, de Silva, Rohini M., Nalin de Silva, K. M., Wijenayaka, Lahiru A., Jayawardana, Kalana, Yan, Mingdi Year: 2016 A rapid and simple one-pot reaction to synthesize stable, spherically shaped silver nanoparticles (AgNps) of different sizes producing distinct optical properties in aqueous solution at ambient temperature has been developed. Each system contains various sizes of silver nanoparticles showing rainbow colours with the peak wavelength of the absorption spectra ranging from 400 to 750 nm. Seven different colours of nano silver were developed through the controlled synthesis of spherical silver nanoparticles using silver nitrate as the metal precursor. Sodium borohydride was used as the main reducing agent and trisodium citrate and hydrazine sulphate were used as the stabilizing and auxiliary reducing agents respectively. The colour of the solution was controlled by varying the concentrations of reagents and the optimum conditions for all the colours are reported. Characterization of silver nanoparticles was carried out using UV-visible spectrophotometry and Transmission Electron Microscopy (TEM). Factors affecting the formation of different sizes of silver nanoparticles, such as silver nitrate concentration, reducing agent concentrations, reaction temperature and reaction pH are also reported. The stability of these coloured silver colloidal solutions was also investigated at different temperatures and the most stable temperature was found to be 4 °C, while the optimum pH to synthesize distinctively coloured silver nanoparticles was found to be in the range of 7–8. The outlined procedure provides a rapid, facile and reproducible synthetic route to spherical AgNps of varying size and ensuing optical properties. Thus, this method is certain to find value in the many applications where size tunability of AgNps is desired. Title: Nanosilver Rainbow: A Rapid and Facile Method to Tune Different Colours of Nanosilver Through the Controlled Synthesis of Stable Spherical Silver Nanoparticles Author: Mendis, Pramujitha, de Silva, Rohini M., Nalin de Silva, K. M., Wijenayaka, Lahiru A., Jayawardana, Kalana, Yan, Mingdi Year: 2016 A rapid and simple one-pot reaction to synthesize stable, spherically shaped silver nanoparticles (AgNps) of different sizes producing distinct optical properties in aqueous solution at ambient temperature has been developed. Each system contains various sizes of silver nanoparticles showing rainbow colours with the peak wavelength of the absorption spectra ranging from 400 to 750 nm. Seven different colours of nano silver were developed through the controlled synthesis of spherical silver nanoparticles using silver nitrate as the metal precursor. Sodium borohydride was used as the main reducing agent and trisodium citrate and hydrazine sulphate were used as the stabilizing and auxiliary reducing agents respectively. The colour of the solution was controlled by varying the concentrations of reagents and the optimum conditions for all the colours are reported. Characterization of silver nanoparticles was carried out using UV-visible spectrophotometry and Transmission Electron Microscopy (TEM). Factors affecting the formation of different sizes of silver nanoparticles, such as silver nitrate concentration, reducing agent concentrations, reaction temperature and reaction pH are also reported. The stability of these coloured silver colloidal solutions was also investigated at different temperatures and the most stable temperature was found to be 4 °C, while the optimum pH to synthesize distinctively coloured silver nanoparticles was found to be in the range of 7–8. The outlined procedure provides a rapid, facile and reproducible synthetic route to spherical AgNps of varying size and ensuing optical properties. Thus, this method is certain to find value in the many applications where size tunability of AgNps is desired. Close

• 51. [Article] Modeling the Thickness of Perennial Ice Covers on Stratified Lakes of the Taylor Valley, Antarctica

  A 1-D ice cover model was developed to predict and constrain drivers of long-term ice thick-ness trends in chemically stratified lakes of Taylor Valley, Antarctica. The model is driven by surface ra-diative ...

  Citation × Citation Citation Abstract Copy Title: Modeling the Thickness of Perennial Ice Covers on Stratified Lakes of the Taylor Valley, Antarctica Author: Obryk, Maciej K., Doran, Peter T., Hicks, Jared A., McKay, Christopher P., Priscu, John Charles Year: 2016 A 1-D ice cover model was developed to predict and constrain drivers of long-term ice thick-ness trends in chemically stratified lakes of Taylor Valley, Antarctica. The model is driven by surface ra-diative heat fluxes and heat fluxes from the underlying water column. The model successfully reproduced 16 a (between 1996 and 2012) of ice thickness changes for the west lobe of Lake Bonney (average ice thickness = 3.53 m) and Lake Fryxell (average ice thickness = 4.22 m). Long-term ice thick-ness trends require coupling with the thermal structure of the water column. The heat stored within the temperature maximum of lakes exceeding a liquid water column depth of 20 m can either impede or fa-cilitate ice thickness change depending on the predominant climatic trend (cooling or warming). As such, shallow (columns) perennially ice-covered lakes without deep temperature maxima are more sensitive indicators of climate change. The long-term ice thickness trends are a result of surface energy flux and heat flux from the deep temperature maximum in the water column, the latter of which results from absorbed solar radiation. Title: Modeling the Thickness of Perennial Ice Covers on Stratified Lakes of the Taylor Valley, Antarctica Author: Obryk, Maciej K., Doran, Peter T., Hicks, Jared A., McKay, Christopher P., Priscu, John Charles Year: 2016 A 1-D ice cover model was developed to predict and constrain drivers of long-term ice thick-ness trends in chemically stratified lakes of Taylor Valley, Antarctica. The model is driven by surface ra-diative heat fluxes and heat fluxes from the underlying water column. The model successfully reproduced 16 a (between 1996 and 2012) of ice thickness changes for the west lobe of Lake Bonney (average ice thickness = 3.53 m) and Lake Fryxell (average ice thickness = 4.22 m). Long-term ice thick-ness trends require coupling with the thermal structure of the water column. The heat stored within the temperature maximum of lakes exceeding a liquid water column depth of 20 m can either impede or fa-cilitate ice thickness change depending on the predominant climatic trend (cooling or warming). As such, shallow (columns) perennially ice-covered lakes without deep temperature maxima are more sensitive indicators of climate change. The long-term ice thickness trends are a result of surface energy flux and heat flux from the deep temperature maximum in the water column, the latter of which results from absorbed solar radiation. Close

• 52. [Article] Modeling Density Currents in a Typical Tributary of the Three Gorges Reservoir, China

  The initial filling of the Three Gorges Reservoir (TGR), China, has caused serious phytoplankton blooms in its tributary bays. A two-dimensional, laterally averaged, hydrodynamic and water quality CE-QUAL-W2 ...

  Citation × Citation Citation Abstract Copy Title: Modeling Density Currents in a Typical Tributary of the Three Gorges Reservoir, China Author: Ma, Jun, Liu, Defu, Wells, Scott A., Tang, Hongwu, Ji, Daobin, Yang, Zhengjian Year: 2015 The initial filling of the Three Gorges Reservoir (TGR), China, has caused serious phytoplankton blooms in its tributary bays. A two-dimensional, laterally averaged, hydrodynamic and water quality CE-QUAL-W2 model was used to simulate the hydrodynamics and water temperature of a typical tributary (Xiangxi Bay XXB) of the TGR to study the relationship between phytoplankton and density currents. The CE-QUAL-W2 model was calibrated to data collected in XXB (depth profiles of velocity and water temperature at three locations) from January 2008 through December 2008. The model performed well in simulating (1) flow velocity profiles, (2) unusual water temperature profiles, (3) the plunge point location of the intrusion layer, (4) propagation speed, and (5) the travel distance of the density currents. The model was then used to examine potential factors that affect the density currents, such as water level fluctuations in the mainstem of the TGR, water temperature differences between the mainstem and XXB, and inflow rates to XXB. Therefore, a better understanding of the hydrodynamics of tributaries in the TGR can be used to understand the aquatic ecosystem dynamics of these tributaries. Title: Modeling Density Currents in a Typical Tributary of the Three Gorges Reservoir, China Author: Ma, Jun, Liu, Defu, Wells, Scott A., Tang, Hongwu, Ji, Daobin, Yang, Zhengjian Year: 2015 The initial filling of the Three Gorges Reservoir (TGR), China, has caused serious phytoplankton blooms in its tributary bays. A two-dimensional, laterally averaged, hydrodynamic and water quality CE-QUAL-W2 model was used to simulate the hydrodynamics and water temperature of a typical tributary (Xiangxi Bay XXB) of the TGR to study the relationship between phytoplankton and density currents. The CE-QUAL-W2 model was calibrated to data collected in XXB (depth profiles of velocity and water temperature at three locations) from January 2008 through December 2008. The model performed well in simulating (1) flow velocity profiles, (2) unusual water temperature profiles, (3) the plunge point location of the intrusion layer, (4) propagation speed, and (5) the travel distance of the density currents. The model was then used to examine potential factors that affect the density currents, such as water level fluctuations in the mainstem of the TGR, water temperature differences between the mainstem and XXB, and inflow rates to XXB. Therefore, a better understanding of the hydrodynamics of tributaries in the TGR can be used to understand the aquatic ecosystem dynamics of these tributaries. Close

• 53. [Article] Characterizing Large-Scale Meteorological Patterns and Associated Temperature and Precipitation Extremes over the Northwestern United States Using Self-Organizing Maps

  The self-organizing maps (SOMs) approach is demonstrated as a way to identify a range of archetypal large-scale meteorological patterns (LSMPs) over the northwestern United States and connect these patterns ...

  Citation × Citation Citation Abstract Copy Title: Characterizing Large-Scale Meteorological Patterns and Associated Temperature and Precipitation Extremes over the Northwestern United States Using Self-Organizing Maps Author: Loikith, Paul C., Lintner, Benjamin R., Sweeney, Alex Year: 2017 The self-organizing maps (SOMs) approach is demonstrated as a way to identify a range of archetypal large-scale meteorological patterns (LSMPs) over the northwestern United States and connect these patterns with local-scale temperature and precipitation extremes. SOMs are used to construct a set of 12 characteristic LSMPs (nodes) based on daily reanalysis circulation fields spanning the range of observed synoptic-scale variability for the summer and winter seasons for the period 1979–2013. Composites of surface variables are constructed for subsets of days assigned to each node to explore relationships between temperature, precipitation, and the node patterns. The SOMs approach also captures interannual variability in daily weather regime frequency related to El Niño–Southern Oscillation. Temperature and precipitation extremes in high-resolution gridded observations and in situ station data show robust relationships with particular nodes in many cases, supporting the approach as a way to identify LSMPs associated with local extremes. Assigning days from the extreme warm summer of 2015 and wet winter of 2016 to nodes illustrates how SOMs may be used to assess future changes in extremes. These results point to the applicability of SOMs to climate model evaluation and assessment of future projections of local-scale extremes without requiring simulations to reliably resolve extremes at high spatial scales. Title: Characterizing Large-Scale Meteorological Patterns and Associated Temperature and Precipitation Extremes over the Northwestern United States Using Self-Organizing Maps Author: Loikith, Paul C., Lintner, Benjamin R., Sweeney, Alex Year: 2017 The self-organizing maps (SOMs) approach is demonstrated as a way to identify a range of archetypal large-scale meteorological patterns (LSMPs) over the northwestern United States and connect these patterns with local-scale temperature and precipitation extremes. SOMs are used to construct a set of 12 characteristic LSMPs (nodes) based on daily reanalysis circulation fields spanning the range of observed synoptic-scale variability for the summer and winter seasons for the period 1979–2013. Composites of surface variables are constructed for subsets of days assigned to each node to explore relationships between temperature, precipitation, and the node patterns. The SOMs approach also captures interannual variability in daily weather regime frequency related to El Niño–Southern Oscillation. Temperature and precipitation extremes in high-resolution gridded observations and in situ station data show robust relationships with particular nodes in many cases, supporting the approach as a way to identify LSMPs associated with local extremes. Assigning days from the extreme warm summer of 2015 and wet winter of 2016 to nodes illustrates how SOMs may be used to assess future changes in extremes. These results point to the applicability of SOMs to climate model evaluation and assessment of future projections of local-scale extremes without requiring simulations to reliably resolve extremes at high spatial scales. Close

• 54. [Article] The Effect of Plasma on Graphene Quality in an Inductively Couple Plasma Chemical Vapor Deposition Reactor

  Despite continued interest in research and application development, full scale graphene production is still limited by many factors including prohibitively high growth temperature requirements. Extremely ...

  Citation × Citation Citation Abstract Copy Title: The Effect of Plasma on Graphene Quality in an Inductively Couple Plasma Chemical Vapor Deposition Reactor Author: Coyne, Brendan Year: 2017 Despite continued interest in research and application development, full scale graphene production is still limited by many factors including prohibitively high growth temperature requirements. Extremely high quality graphene growth is possible at high temperatures using chemical vapor deposition (CVD). Use of an inductively coupled plasma chemical vapor deposition (ICP CVD) reactor with the benefit of precursor gas decomposition through plasma generation, may provide possibility to reduce growth temperature. Herein, we report plasma’s effects on graphene growth by comparing growths of increasing power supplied to plasma generation and changes in precursor gas ratios. Plasma composition was characterized by ultraviolet and visible light spectroscopy; graphene was characterized by Raman spectroscopy. Plasma was observed to change gradually and in a threshold shift. Gradual changes in plasma resulted in changes in graphene quality, both defect density and number of layers. The shift produced sudden changes in graphene quality. Further, increasing power before and after the shift produced opposite correlated trends. Finally, reduced hydrogen to acetylene gas ratios produced plasma associated with higher powers at a higher gas ratio. Though the comparative plasma spectra between the two reduced gas ratio growths were very similar, the quality of graphene was different. Additionally, both lower gas ratio growths produced quality different than what was expected by the trends suggested by the higher gas ratio growths. Though plasma demonstrated a role in graphene quality, a more detailed understand of its driving mechanisms must be developed in conjunction with other growth mechanisms if it is to be utilized to substantially reduce growth temperature. Title: The Effect of Plasma on Graphene Quality in an Inductively Couple Plasma Chemical Vapor Deposition Reactor Author: Coyne, Brendan Year: 2017 Despite continued interest in research and application development, full scale graphene production is still limited by many factors including prohibitively high growth temperature requirements. Extremely high quality graphene growth is possible at high temperatures using chemical vapor deposition (CVD). Use of an inductively coupled plasma chemical vapor deposition (ICP CVD) reactor with the benefit of precursor gas decomposition through plasma generation, may provide possibility to reduce growth temperature. Herein, we report plasma’s effects on graphene growth by comparing growths of increasing power supplied to plasma generation and changes in precursor gas ratios. Plasma composition was characterized by ultraviolet and visible light spectroscopy; graphene was characterized by Raman spectroscopy. Plasma was observed to change gradually and in a threshold shift. Gradual changes in plasma resulted in changes in graphene quality, both defect density and number of layers. The shift produced sudden changes in graphene quality. Further, increasing power before and after the shift produced opposite correlated trends. Finally, reduced hydrogen to acetylene gas ratios produced plasma associated with higher powers at a higher gas ratio. Though the comparative plasma spectra between the two reduced gas ratio growths were very similar, the quality of graphene was different. Additionally, both lower gas ratio growths produced quality different than what was expected by the trends suggested by the higher gas ratio growths. Though plasma demonstrated a role in graphene quality, a more detailed understand of its driving mechanisms must be developed in conjunction with other growth mechanisms if it is to be utilized to substantially reduce growth temperature. Close

• 55. [Article] Measuring the Effects of Parking Lots and Tree Shading on Microscale Urban Heat Islands

  55 pages. A thesis presented to the Department of Planning, Public Policy, and Management and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree ...

  Citation × Citation Citation Abstract Copy Title: Measuring the Effects of Parking Lots and Tree Shading on Microscale Urban Heat Islands Author: Goodrich, Elliot Year: 2016 55 pages. A thesis presented to the Department of Planning, Public Policy, and Management and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Arts, Winter 2016. Title: Measuring the Effects of Parking Lots and Tree Shading on Microscale Urban Heat Islands Author: Goodrich, Elliot Year: 2016 55 pages. A thesis presented to the Department of Planning, Public Policy, and Management and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Arts, Winter 2016. Close

• 56. [Article] The Neurodevelopmental and Genetic Basis to Natural Variation in Thermal Preference Behavior in Caenorhabditis elegans

  In a heterogeneous environment where temperature influences fitness, individuals must navigate to a thermal optimum to maximize reproductive output and minimize physiological stress. However, the optimal ...

  Citation × Citation Citation Abstract Copy Title: The Neurodevelopmental and Genetic Basis to Natural Variation in Thermal Preference Behavior in Caenorhabditis elegans Author: Gaertner, Bryn Year: 2012, 2014 In a heterogeneous environment where temperature influences fitness, individuals must navigate to a thermal optimum to maximize reproductive output and minimize physiological stress. However, the optimal temperature varies among individuals due to genetic and environmental contributions. The neural and genetic basis to such natural variation in behavior has remained elusive in most cases, as the high-throughput genomic, neurodevelopmental, and behavioral techniques were not developed. Using the nematode Title: The Neurodevelopmental and Genetic Basis to Natural Variation in Thermal Preference Behavior in Caenorhabditis elegans Author: Gaertner, Bryn Year: 2012, 2014 In a heterogeneous environment where temperature influences fitness, individuals must navigate to a thermal optimum to maximize reproductive output and minimize physiological stress. However, the optimal temperature varies among individuals due to genetic and environmental contributions. The neural and genetic basis to such natural variation in behavior has remained elusive in most cases, as the high-throughput genomic, neurodevelopmental, and behavioral techniques were not developed. Using the nematode Close

• 57. [Article] Bow-Free Tri-Component Mechanically Pre-Stressed Failure-Oriented-Accelerated-Test (FOAT) Specimen

  In some today's and future electronic and optoelectronic packaging systems (assemblies), including those intended for aerospace applications, the package (system's component containing active and passive ...

  Citation × Citation Citation Abstract Copy Title: Bow-Free Tri-Component Mechanically Pre-Stressed Failure-Oriented-Accelerated-Test (FOAT) Specimen Author: Suhir, Ephraim, Bensoussan, Alain, Nicolics, Johann Year: 2015 In some today's and future electronic and optoelectronic packaging systems (assemblies), including those intended for aerospace applications, the package (system's component containing active and passive devices and interconnects) is placed (sandwiched) between two substrates. In an approximate stress analysis these substrates could be considered, from the mechanical (physical) standpoint, identical. Such assemblies are certainly bow-free, provided that all the stresses are within the elastic range and remain elastic during testing and operation. Ability to remain bow-free is an important merit for many applications. This is particularly true in optical engineering, where there is always a need to maintain high coupling efficiency. The level of thermal stresses in bow-free assemblies of the type in question could be, however, rather high. High thermal stresses are caused by the thermal contraction mismatch of the dissimilar materials of the assembly components and occur at low temperature conditions. These stresses include normal stresses acting in the component cross-sections and interfacial shearing and peeling stresses. The normal stresses in the component cross-sections determine the reliability of the component materials and the devices embedded into the inner component (package). The interfacial stresses affect the adhesive and cohesive strength of the assembly, i.e. its integrity. It should be pointed out that although the assembly as a whole is bow-free, the peeling stresses in it, whether thermal or mechanical, are not necessarily low: the two outer components (substrates) might exhibit appreciable warpage with respect to the bow-free inner component (package). While there is an incentive for using bow-free assemblies, there is also an incentive for narrowing the temperature range of the accelerated reliability testing: elevated temperature excursions might produce an undesirable shift in the modes and mechanisms of failure, i.e. lead to failures that will hardly occur in actual operation conditions. Failure oriented accelerated test (FOAT) specimens are particularly vulnerable, since the temperature range in these tests should be broad enough to lead to a failure, and, if a shift in the modes and mechanisms of failures takes place during significant temperature excursions, the physics of such failures might be quite different of those in actual operation conditions. Mechanical pre-stressing can be an effective means for narrowing the range of temperature excursions during accelerated testing and, owing to that, - for obtaining consistent and trustworthy information. If pre-stressing is considered, the ability to predict the thermo-mechanical stresses in the test specimen is certainly a must. Accordingly, the objective of this analysis is to obtain simple, easy-to-use, physically meaningful and practically useful closed form solutions for the evaluation of stresses in a bow-free test specimen of the type in question. The emphasis is on the role of compliant attachments, if any, between the inner and the two outer components. The developed model can be used at the design and accelerated test stages of the development of bow-free electronic and optoelectronic products. The compliant attachments, if any, could be particularly comprised of beamlike solder joint interconnections that, if properly designed, have a potential to relieve the thermal stresses to an extent that the low-cycle-fatigue state-of-stress is avoided. Title: Bow-Free Tri-Component Mechanically Pre-Stressed Failure-Oriented-Accelerated-Test (FOAT) Specimen Author: Suhir, Ephraim, Bensoussan, Alain, Nicolics, Johann Year: 2015 In some today's and future electronic and optoelectronic packaging systems (assemblies), including those intended for aerospace applications, the package (system's component containing active and passive devices and interconnects) is placed (sandwiched) between two substrates. In an approximate stress analysis these substrates could be considered, from the mechanical (physical) standpoint, identical. Such assemblies are certainly bow-free, provided that all the stresses are within the elastic range and remain elastic during testing and operation. Ability to remain bow-free is an important merit for many applications. This is particularly true in optical engineering, where there is always a need to maintain high coupling efficiency. The level of thermal stresses in bow-free assemblies of the type in question could be, however, rather high. High thermal stresses are caused by the thermal contraction mismatch of the dissimilar materials of the assembly components and occur at low temperature conditions. These stresses include normal stresses acting in the component cross-sections and interfacial shearing and peeling stresses. The normal stresses in the component cross-sections determine the reliability of the component materials and the devices embedded into the inner component (package). The interfacial stresses affect the adhesive and cohesive strength of the assembly, i.e. its integrity. It should be pointed out that although the assembly as a whole is bow-free, the peeling stresses in it, whether thermal or mechanical, are not necessarily low: the two outer components (substrates) might exhibit appreciable warpage with respect to the bow-free inner component (package). While there is an incentive for using bow-free assemblies, there is also an incentive for narrowing the temperature range of the accelerated reliability testing: elevated temperature excursions might produce an undesirable shift in the modes and mechanisms of failure, i.e. lead to failures that will hardly occur in actual operation conditions. Failure oriented accelerated test (FOAT) specimens are particularly vulnerable, since the temperature range in these tests should be broad enough to lead to a failure, and, if a shift in the modes and mechanisms of failures takes place during significant temperature excursions, the physics of such failures might be quite different of those in actual operation conditions. Mechanical pre-stressing can be an effective means for narrowing the range of temperature excursions during accelerated testing and, owing to that, - for obtaining consistent and trustworthy information. If pre-stressing is considered, the ability to predict the thermo-mechanical stresses in the test specimen is certainly a must. Accordingly, the objective of this analysis is to obtain simple, easy-to-use, physically meaningful and practically useful closed form solutions for the evaluation of stresses in a bow-free test specimen of the type in question. The emphasis is on the role of compliant attachments, if any, between the inner and the two outer components. The developed model can be used at the design and accelerated test stages of the development of bow-free electronic and optoelectronic products. The compliant attachments, if any, could be particularly comprised of beamlike solder joint interconnections that, if properly designed, have a potential to relieve the thermal stresses to an extent that the low-cycle-fatigue state-of-stress is avoided. Close

• 58. [Article] <i>Wolbachia-</i>Host Interactions and the Implications to Insect Conservation and Management

  Parasitic reproductive endosymbionts are emerging as formidable threats to insect biodiversity. Wolbachia are prevalent maternally inherited intra-cellular bacteria found in >50% of arthropod species. ...

  Citation × Citation Citation Abstract Copy Title: <i>Wolbachia-</i>Host Interactions and the Implications to Insect Conservation and Management Author: Truitt, Amy Michelle Year: 2017 Parasitic reproductive endosymbionts are emerging as formidable threats to insect biodiversity. Wolbachia are prevalent maternally inherited intra-cellular bacteria found in >50% of arthropod species. These symbiotic bacteria interact with their hosts in diverse ways, most often they alter host reproduction causing four conditions that all selectively favor infected females: feminization, male killing, parthenogenesis, and cytoplasmic incompatibility (CI). Furthermore, depending on strain-type and host genetic background, Wolbachia are known to affect insect behavior, expand or shift host thermal tolerance ranges, and confer anti-viral protection to their hosts. Because Wolbachia both reside in and are transmitted with host cell cytoplasm, mitochondria and other cytoplasmically inherited genetic elements become linked with the bacteria. Thus, by enhancing their own transmission, Wolbachia-induced phenotypes can lead to mitochondrial selective sweeps, which may have profound impacts on vulnerable and small insect populations. Elucidating the extent to which endosymbionts influence biological and ecological functions is pivotal to making management decisions regarding imperiled insect species. My dissertation investigates biological and ecological impacts of host-endosymbiont interactions by examining Wolbachia infections in three different host systems. First, I used the federally threatened butterfly species Speyeria zerene hippolyta to determine whether the general reproductive success of local populations was affected by the introduction of CI-inducing Wolbachia-infected butterflies through implemented species recovery programs. Next, by characterizing the Wolbachia infections of parasitoids associated with the Eurema butterfly clade, I analyzed whether host-parasitoid interactions provide a path for interspecies horizontal transmission. Finally, I conducted a laboratory experiment using an isogenic Drosophila melanogaster line to determine whether Wolbachia influence host temperature preference. Together, my research examines how the individual level effects of host-endosymbiont interactions can expand into populations, have broader impacts on insect communities, and potentially impede the conservation and management of insects in nature. In chapter one, I screened S. z. hippolyta samples from three extant populations for Wolbachia infection. To examine the impacts of Wolbachia on small populations, I analyzed and compared infected and uninfected S. z. hippolyta reproductive data and showed that, in a population composed of infected and uninfected S. z. hippolyta, uninfected butterflies had reduced reproductive success (GLMM z = -8.067, P < 0.0001). I then developed a single-population demographic theoretical model using these same reproductive data to simulate and analyze different potential dynamics of small populations resulting from population supplementation with uninfected, CI-Wolbachia infected, or combined uninfected and infected butterflies. Analysis of model simulations revealed that supplementation with CI-inducing butterflies significantly suppressed host-population size (ANOVA F5,593 = 3349, PWolbachia-infected individuals (Tukey's post-hoc test P < 0.0001). In addition, supplementation by multiple releases using a combination of 50 infected and 300 uninfected butterflies has a less severe suppression effect, reducing the population by 75.8%, but the reduction occurs 42.6% faster than with the single release of 50 Wolbachia-infected butterflies (Tukey's post-doc test P < 0.0001). Parasitoid-host interactions have emerged as probable ecological relationships to facilitate horizontal transmission of Wolbachia. In chapter two, I addressed horizontal transmission using Eurema butterflies and their associated parasitoids. From four locations in Northern Queensland, Australia, I collected a total of 404 Eurema hecabe butterfly larvae. Twenty-three parasitoids emerged from the larvae of which 21 were Diptera and two were Hymenoptera. I amplified COI loci fragments from each parasitoid for BLAST query searches and found that 20 individual Diptera parasitoids matched to the genus Exorista and one to the genus Senometopia. One of the Hymenoptera parasitoids matched to the genus Microoplitis and the other to the genus Cotesia. To characterize Wolbachia infections, I used Wolbachia Multi Locus Sequencing Technique (MLST) and discovered that all 20 Exorista parasitoids were infected with an identical Wolbachia strain (ST-41), which is the same strain infecting their Eurema hecabe butterfly hosts. Although, further experiments are necessary to definitively determine that ST-41 Wolbachia are incorporated into germline cells of the parasitoids, this is the first study to provide ecological evidence for inter-ordinal Wolbachia transmission between Lepidoptera and Diptera. Furthermore, this discovery exposes the risk of population augmentation programs that move insects, potentially facilitating the spread of Wolbachia between species within a community through the accidental introduction of new Wolbachia-infected parasitoids. Finally, both Wolbachia and their insect hosts are temperature sensitive organisms. Wolbachia’s replication behavior in their hosts is positively-temperature dependent, while environmental variation can have profound effects on insect’s immune function, fitness, and fecundity. In chapter three, I conducted a laboratory experiment using a thermal gradient choice assay and an isogenic Drosophila melanogaster line with four different Wolbachia infection statuses – uninfected, wMel, wMelCS, and wMelPop - to assess whether a relationship existed between Wolbachia infection and host temperature preference. Results from my laboratory experiment revealed that Wolbachia-infected flies preferred cooler temperatures compared to uninfected flies. Moreover, D. melanogaster temperature preferences varied depending on the Wolbachia strain variant with which they were infected; flies infected with the wMel strain had temperature preferences 2°C cooler compared to uninfected flies; flies infected with either wMelCS or wMelPop strains had preferred temperatures 8°C cooler compared to uninfected flies. Wolbachia-associated temperature preference variation within a species can lead to conspecifics occupying different microclimates, genetically adapting to different sets of specific environmental conditions, and may eventually result in ecological and reproductive isolation. While, reproduction isolation is recognized as one of the first stages in speciation, in small populations of endangered and threatened species, the inability to reproduce between conspecifics can drive species to extirpation or extinction. Collectively, the three chapters of my dissertation set precedent for future integration of host-endosymbiont research prior to implementing population supplementation or translocation programs for the conservation of imperiled insects. Title: <i>Wolbachia-</i>Host Interactions and the Implications to Insect Conservation and Management Author: Truitt, Amy Michelle Year: 2017 Parasitic reproductive endosymbionts are emerging as formidable threats to insect biodiversity. Wolbachia are prevalent maternally inherited intra-cellular bacteria found in >50% of arthropod species. These symbiotic bacteria interact with their hosts in diverse ways, most often they alter host reproduction causing four conditions that all selectively favor infected females: feminization, male killing, parthenogenesis, and cytoplasmic incompatibility (CI). Furthermore, depending on strain-type and host genetic background, Wolbachia are known to affect insect behavior, expand or shift host thermal tolerance ranges, and confer anti-viral protection to their hosts. Because Wolbachia both reside in and are transmitted with host cell cytoplasm, mitochondria and other cytoplasmically inherited genetic elements become linked with the bacteria. Thus, by enhancing their own transmission, Wolbachia-induced phenotypes can lead to mitochondrial selective sweeps, which may have profound impacts on vulnerable and small insect populations. Elucidating the extent to which endosymbionts influence biological and ecological functions is pivotal to making management decisions regarding imperiled insect species. My dissertation investigates biological and ecological impacts of host-endosymbiont interactions by examining Wolbachia infections in three different host systems. First, I used the federally threatened butterfly species Speyeria zerene hippolyta to determine whether the general reproductive success of local populations was affected by the introduction of CI-inducing Wolbachia-infected butterflies through implemented species recovery programs. Next, by characterizing the Wolbachia infections of parasitoids associated with the Eurema butterfly clade, I analyzed whether host-parasitoid interactions provide a path for interspecies horizontal transmission. Finally, I conducted a laboratory experiment using an isogenic Drosophila melanogaster line to determine whether Wolbachia influence host temperature preference. Together, my research examines how the individual level effects of host-endosymbiont interactions can expand into populations, have broader impacts on insect communities, and potentially impede the conservation and management of insects in nature. In chapter one, I screened S. z. hippolyta samples from three extant populations for Wolbachia infection. To examine the impacts of Wolbachia on small populations, I analyzed and compared infected and uninfected S. z. hippolyta reproductive data and showed that, in a population composed of infected and uninfected S. z. hippolyta, uninfected butterflies had reduced reproductive success (GLMM z = -8.067, P < 0.0001). I then developed a single-population demographic theoretical model using these same reproductive data to simulate and analyze different potential dynamics of small populations resulting from population supplementation with uninfected, CI-Wolbachia infected, or combined uninfected and infected butterflies. Analysis of model simulations revealed that supplementation with CI-inducing butterflies significantly suppressed host-population size (ANOVA F5,593 = 3349, PWolbachia-infected individuals (Tukey's post-hoc test P < 0.0001). In addition, supplementation by multiple releases using a combination of 50 infected and 300 uninfected butterflies has a less severe suppression effect, reducing the population by 75.8%, but the reduction occurs 42.6% faster than with the single release of 50 Wolbachia-infected butterflies (Tukey's post-doc test P < 0.0001). Parasitoid-host interactions have emerged as probable ecological relationships to facilitate horizontal transmission of Wolbachia. In chapter two, I addressed horizontal transmission using Eurema butterflies and their associated parasitoids. From four locations in Northern Queensland, Australia, I collected a total of 404 Eurema hecabe butterfly larvae. Twenty-three parasitoids emerged from the larvae of which 21 were Diptera and two were Hymenoptera. I amplified COI loci fragments from each parasitoid for BLAST query searches and found that 20 individual Diptera parasitoids matched to the genus Exorista and one to the genus Senometopia. One of the Hymenoptera parasitoids matched to the genus Microoplitis and the other to the genus Cotesia. To characterize Wolbachia infections, I used Wolbachia Multi Locus Sequencing Technique (MLST) and discovered that all 20 Exorista parasitoids were infected with an identical Wolbachia strain (ST-41), which is the same strain infecting their Eurema hecabe butterfly hosts. Although, further experiments are necessary to definitively determine that ST-41 Wolbachia are incorporated into germline cells of the parasitoids, this is the first study to provide ecological evidence for inter-ordinal Wolbachia transmission between Lepidoptera and Diptera. Furthermore, this discovery exposes the risk of population augmentation programs that move insects, potentially facilitating the spread of Wolbachia between species within a community through the accidental introduction of new Wolbachia-infected parasitoids. Finally, both Wolbachia and their insect hosts are temperature sensitive organisms. Wolbachia’s replication behavior in their hosts is positively-temperature dependent, while environmental variation can have profound effects on insect’s immune function, fitness, and fecundity. In chapter three, I conducted a laboratory experiment using a thermal gradient choice assay and an isogenic Drosophila melanogaster line with four different Wolbachia infection statuses – uninfected, wMel, wMelCS, and wMelPop - to assess whether a relationship existed between Wolbachia infection and host temperature preference. Results from my laboratory experiment revealed that Wolbachia-infected flies preferred cooler temperatures compared to uninfected flies. Moreover, D. melanogaster temperature preferences varied depending on the Wolbachia strain variant with which they were infected; flies infected with the wMel strain had temperature preferences 2°C cooler compared to uninfected flies; flies infected with either wMelCS or wMelPop strains had preferred temperatures 8°C cooler compared to uninfected flies. Wolbachia-associated temperature preference variation within a species can lead to conspecifics occupying different microclimates, genetically adapting to different sets of specific environmental conditions, and may eventually result in ecological and reproductive isolation. While, reproduction isolation is recognized as one of the first stages in speciation, in small populations of endangered and threatened species, the inability to reproduce between conspecifics can drive species to extirpation or extinction. Collectively, the three chapters of my dissertation set precedent for future integration of host-endosymbiont research prior to implementing population supplementation or translocation programs for the conservation of imperiled insects. Close

• 59. [Article] Effects of Selective Logging and Roads on Instream Fine Sediments and Macroinvertebrate Assemblages in the Clackamas Basin, Oregon

  Logging and associated skid trails, haul routes, and roads can have significant impacts on the magnitude and timing of sediments in streams in forested watersheds. Loss of vegetation, soil compaction, ...

  Citation × Citation Citation Abstract Copy Title: Effects of Selective Logging and Roads on Instream Fine Sediments and Macroinvertebrate Assemblages in the Clackamas Basin, Oregon Author: Hood, Paula Elizabeth Year: 2015 Logging and associated skid trails, haul routes, and roads can have significant impacts on the magnitude and timing of sediments in streams in forested watersheds. Loss of vegetation, soil compaction, use of heavy logging equipment, and alteration of natural hydrologic patterns within the watershed can increase landslide rates, create erosion, and generate fine sediments. Selective logging, also called thinning, is a logging practice that leaves some trees within sale units unharvested. The ecological impacts of thinning on stream ecosystems are not fully understood and need further study. My hypothesis was that macroinvertebrate assemblages would be different in streams in non-reference areas that contain recent selective logging compared to streams in reference areas, and in downstream vs. upstream of selective logging units. I also hypothesized that selective logging and high road densities would be associated with increased instream fine sediments. I sampled water quality parameters and macroinvertebrates in three managed and three reference streams in the Clackamas River Basin during the field season of 2013. Turbidity, temperature, dissolved oxygen, conductivity, total dissolved solids (TDS), suspended sediment concentrations (SSC), and flow were sampled at each stream on four occasions during spring through early fall. Macroinvertebrates were sampled once in late summer or early fall. EPA rapid habitat assessments, canopy cover, pebble counts, embeddedness, and slope were also determined. Water quality parameters and macroinvertebrate indices in reference and non-reference sites were compared using t-tests, Welch's tests, or rank based equivalents. Macroinvertebrate assemblage patterns and associated environmental variables were characterized using non-metric multidimensional scaling (NMDS) ordination plots and envfit overlays. Macroinvertebrates had higher abundance and taxa richness in non-reference streams, and indices suggested poorer water quality in non-reference streams. Non-reference streams had a lower percentage of shredders and a higher portion of gatherer-collectors. Associations between land use, fine sediments, and changes in macroinvertebrate metrics and community assemblages were apparent at the reference vs. non-reference scale. It is likely that macroinvertebrates are responding, at least in part, to past logging and high road densities in non-reference streams. Fewer indications were found that recent logging may be affecting water quality and macroinvertebrates. Pearson's correlation coefficients show that the percent of recent logging upstream of study sites was correlated with several measures of fine sediments, suggesting that recent land use may be affecting sediment levels at the subwatershed scale. Stream temperatures increased from upstream to downstream in non-reference sites. Though no continual stream temperature data were collected in this study, the history of continuing temperature standard exceedances in the area suggest that further investigation of how selective logging may be affecting stream temperature and other water quality parameters in the Clackamas Basin is warranted. No other differences in water quality parameters were found from upstream to downstream, possibly because water quality was sufficiently protected, or because signals from land use impacts may be obscured by a several factors, including upstream confounding factors such as roads and past logging, and natural variability. Title: Effects of Selective Logging and Roads on Instream Fine Sediments and Macroinvertebrate Assemblages in the Clackamas Basin, Oregon Author: Hood, Paula Elizabeth Year: 2015 Logging and associated skid trails, haul routes, and roads can have significant impacts on the magnitude and timing of sediments in streams in forested watersheds. Loss of vegetation, soil compaction, use of heavy logging equipment, and alteration of natural hydrologic patterns within the watershed can increase landslide rates, create erosion, and generate fine sediments. Selective logging, also called thinning, is a logging practice that leaves some trees within sale units unharvested. The ecological impacts of thinning on stream ecosystems are not fully understood and need further study. My hypothesis was that macroinvertebrate assemblages would be different in streams in non-reference areas that contain recent selective logging compared to streams in reference areas, and in downstream vs. upstream of selective logging units. I also hypothesized that selective logging and high road densities would be associated with increased instream fine sediments. I sampled water quality parameters and macroinvertebrates in three managed and three reference streams in the Clackamas River Basin during the field season of 2013. Turbidity, temperature, dissolved oxygen, conductivity, total dissolved solids (TDS), suspended sediment concentrations (SSC), and flow were sampled at each stream on four occasions during spring through early fall. Macroinvertebrates were sampled once in late summer or early fall. EPA rapid habitat assessments, canopy cover, pebble counts, embeddedness, and slope were also determined. Water quality parameters and macroinvertebrate indices in reference and non-reference sites were compared using t-tests, Welch's tests, or rank based equivalents. Macroinvertebrate assemblage patterns and associated environmental variables were characterized using non-metric multidimensional scaling (NMDS) ordination plots and envfit overlays. Macroinvertebrates had higher abundance and taxa richness in non-reference streams, and indices suggested poorer water quality in non-reference streams. Non-reference streams had a lower percentage of shredders and a higher portion of gatherer-collectors. Associations between land use, fine sediments, and changes in macroinvertebrate metrics and community assemblages were apparent at the reference vs. non-reference scale. It is likely that macroinvertebrates are responding, at least in part, to past logging and high road densities in non-reference streams. Fewer indications were found that recent logging may be affecting water quality and macroinvertebrates. Pearson's correlation coefficients show that the percent of recent logging upstream of study sites was correlated with several measures of fine sediments, suggesting that recent land use may be affecting sediment levels at the subwatershed scale. Stream temperatures increased from upstream to downstream in non-reference sites. Though no continual stream temperature data were collected in this study, the history of continuing temperature standard exceedances in the area suggest that further investigation of how selective logging may be affecting stream temperature and other water quality parameters in the Clackamas Basin is warranted. No other differences in water quality parameters were found from upstream to downstream, possibly because water quality was sufficiently protected, or because signals from land use impacts may be obscured by a several factors, including upstream confounding factors such as roads and past logging, and natural variability. Close

• 60. [Article] Influence of Mixing and Buoyancy on Competition Between Cyanobacteria Species in Upper Klamath Lake

  Cyanobacterial blooms in lakes impact human health, the economy, and ecosystem health. It is predicted that climate change will promote and increase the frequency and intensity of cyanobacterial blooms ...

  Citation × Citation Citation Abstract Copy Title: Influence of Mixing and Buoyancy on Competition Between Cyanobacteria Species in Upper Klamath Lake Author: Brunkalla, Roberta Year: 2017 Cyanobacterial blooms in lakes impact human health, the economy, and ecosystem health. It is predicted that climate change will promote and increase the frequency and intensity of cyanobacterial blooms due to unique physiological adaptions that allow cyanobacteria to exploit warm stable water bodies. Key cyanobacteria physiological adaptions include nitrogen fixation, buoyancy regulation and higher optimum growth temperatures. The largest uncertainty of predicting the effect of climate change is in understanding how the interactions among species will change. Adding to the ambiguity, cyanobacteria physiological adaptions can vary based on lakespecific ecotypes and can have different sensitivities to temperature. It is critical to understand how cyanobacterial physiological adaptions impact species interactions in order to improve and devise adaptable, short‐term management methods for bloom control. This study investigated how weather patterns and algal buoyancy regulation influence the competition and accumulation of two bloom‐forming buoyant cyanobacteria species (Aphanizomenon flos‐aquae (APFA) and toxin‐forming Microcystis aeruginosa (MSAE)) in Upper Klamath Lake (UKL), Oregon. The focus was confirming the buoyancy rate of the APFA in Upper Klamath Lake and exploring whether short‐term weather conditions could lead to dangerous accumulations of APFA or MSAE. A sensitivity analysis was conducted on the model’s buoyancy terms and growth curves to see if the outcome of competition was influenced by these parameters. UKL specific buoyancy rates were measured on APFA from samples taken directly from the lake in the summer of 2015. Tracking software was used to measure APFA movement through water, and individual colony movement was averaged to obtain a single buoyancy rate. There was a high degree of agreement between the calculated APFA buoyancy rate in UKL (o.89 ± 0.34 m hr-1) with the rate published by Walsby (1995; 0.9 ± 0-.5 m hr-1). This study investigated how weather patterns and buoyancy regulation influenced the outcome of competition between APFA and MSAE. Weather and water column temperature data were collected from UKL in the summer of 2016. A onedimensional hydrodynamic model was used to calculate the lake’s thermal and turbulence structure on days with contrasting weather patterns (hot/cool and windy/calm). A competition model was used to calculate the accumulation of APFA and MSAE cells in regular intervals through the water column under the various weather scenarios. MSAE accumulation was significantly influenced by the thermal and turbulence regimes, but APFA maintained high accumulations under every regime and was the better competitor under every thermal and turbulence regime. MSAE was more negatively impacted by high turbulence than low temperatures. APFA’s optimum temperature growth curve was found to be important in determining the outcome of competition between APFA and MSAE. Surprisingly, competition was not sensitive to changes in buoyancy rates. Buoyancy was not found to be a function of algal accumulation under any thermal and turbulence regime. The impacts of climate change and human‐induced enrichment has the potential to change existing patterns of species interactions in lentic systems. Restoration and management efforts should consider the significance of cascading ecological responses to climate change. Understanding how key physiological adaptions operate is the first step to assessing the scope of this impact. While buoyancy might not play a large role in competition in UKL, it might be possible to use mixing to suppress MSAE because it is negatively impacted by high turbulence. If MSAE hot spots become a reoccurring problem in UKL, lakes managers might be able to use localized mixing to suppress MSAE blooms in these problem areas. Title: Influence of Mixing and Buoyancy on Competition Between Cyanobacteria Species in Upper Klamath Lake Author: Brunkalla, Roberta Year: 2017 Cyanobacterial blooms in lakes impact human health, the economy, and ecosystem health. It is predicted that climate change will promote and increase the frequency and intensity of cyanobacterial blooms due to unique physiological adaptions that allow cyanobacteria to exploit warm stable water bodies. Key cyanobacteria physiological adaptions include nitrogen fixation, buoyancy regulation and higher optimum growth temperatures. The largest uncertainty of predicting the effect of climate change is in understanding how the interactions among species will change. Adding to the ambiguity, cyanobacteria physiological adaptions can vary based on lakespecific ecotypes and can have different sensitivities to temperature. It is critical to understand how cyanobacterial physiological adaptions impact species interactions in order to improve and devise adaptable, short‐term management methods for bloom control. This study investigated how weather patterns and algal buoyancy regulation influence the competition and accumulation of two bloom‐forming buoyant cyanobacteria species (Aphanizomenon flos‐aquae (APFA) and toxin‐forming Microcystis aeruginosa (MSAE)) in Upper Klamath Lake (UKL), Oregon. The focus was confirming the buoyancy rate of the APFA in Upper Klamath Lake and exploring whether short‐term weather conditions could lead to dangerous accumulations of APFA or MSAE. A sensitivity analysis was conducted on the model’s buoyancy terms and growth curves to see if the outcome of competition was influenced by these parameters. UKL specific buoyancy rates were measured on APFA from samples taken directly from the lake in the summer of 2015. Tracking software was used to measure APFA movement through water, and individual colony movement was averaged to obtain a single buoyancy rate. There was a high degree of agreement between the calculated APFA buoyancy rate in UKL (o.89 ± 0.34 m hr-1) with the rate published by Walsby (1995; 0.9 ± 0-.5 m hr-1). This study investigated how weather patterns and buoyancy regulation influenced the outcome of competition between APFA and MSAE. Weather and water column temperature data were collected from UKL in the summer of 2016. A onedimensional hydrodynamic model was used to calculate the lake’s thermal and turbulence structure on days with contrasting weather patterns (hot/cool and windy/calm). A competition model was used to calculate the accumulation of APFA and MSAE cells in regular intervals through the water column under the various weather scenarios. MSAE accumulation was significantly influenced by the thermal and turbulence regimes, but APFA maintained high accumulations under every regime and was the better competitor under every thermal and turbulence regime. MSAE was more negatively impacted by high turbulence than low temperatures. APFA’s optimum temperature growth curve was found to be important in determining the outcome of competition between APFA and MSAE. Surprisingly, competition was not sensitive to changes in buoyancy rates. Buoyancy was not found to be a function of algal accumulation under any thermal and turbulence regime. The impacts of climate change and human‐induced enrichment has the potential to change existing patterns of species interactions in lentic systems. Restoration and management efforts should consider the significance of cascading ecological responses to climate change. Understanding how key physiological adaptions operate is the first step to assessing the scope of this impact. While buoyancy might not play a large role in competition in UKL, it might be possible to use mixing to suppress MSAE because it is negatively impacted by high turbulence. If MSAE hot spots become a reoccurring problem in UKL, lakes managers might be able to use localized mixing to suppress MSAE blooms in these problem areas. Close

• 61. [Article] Constant Interface Temperature Reliability Assessment Method: An Alternative Method for Testing Thermal Interface Material in Products

  As electronic packages and their thermal solutions become more complex the reliability margins in the thermal solutions diminish and become less tolerant to errors in reliability predictions. The current ...

  Citation × Citation Citation Abstract Copy Title: Constant Interface Temperature Reliability Assessment Method: An Alternative Method for Testing Thermal Interface Material in Products Author: Amoah-Kusi, Christian Year: 2015 As electronic packages and their thermal solutions become more complex the reliability margins in the thermal solutions diminish and become less tolerant to errors in reliability predictions. The current method of thermally stress testing thermal solutions can be over or under predicting end of life thermal performance. Benefits of accurate testing and modeling are improved silicon yield in manufacturing, improved performance, lower cost thermal solutions, and shortened test times. The current method of thermally stress testing is to place the entire unit in an elevated isothermal temperature and periodically measure thermal performance. Isothermally aging is not an accurate representation of how the unit will be used by the customer and does not capture the thermal gradients and mechanical stresses due to different coefficients of thermal expansion of the materials used in the thermal solution. A new testing system, CITRAM which is an acronym for Constant Interface Temperature Reliability Method, has been developed that uses an electronic test board. The approach captures the thermal and mechanical stresses accurately and improves test time by 20-30% as a result of automation. Through this study a difference in the two methods has been identified and the new CITRAM method should be adopted as current practice. Title: Constant Interface Temperature Reliability Assessment Method: An Alternative Method for Testing Thermal Interface Material in Products Author: Amoah-Kusi, Christian Year: 2015 As electronic packages and their thermal solutions become more complex the reliability margins in the thermal solutions diminish and become less tolerant to errors in reliability predictions. The current method of thermally stress testing thermal solutions can be over or under predicting end of life thermal performance. Benefits of accurate testing and modeling are improved silicon yield in manufacturing, improved performance, lower cost thermal solutions, and shortened test times. The current method of thermally stress testing is to place the entire unit in an elevated isothermal temperature and periodically measure thermal performance. Isothermally aging is not an accurate representation of how the unit will be used by the customer and does not capture the thermal gradients and mechanical stresses due to different coefficients of thermal expansion of the materials used in the thermal solution. A new testing system, CITRAM which is an acronym for Constant Interface Temperature Reliability Method, has been developed that uses an electronic test board. The approach captures the thermal and mechanical stresses accurately and improves test time by 20-30% as a result of automation. Through this study a difference in the two methods has been identified and the new CITRAM method should be adopted as current practice. Close

• 62. [Article] Geothermometry of Two Cascade Geothermal Systems

  For this thesis I applied classical and multi-component geothermometry techniques to new water chemistry data from Breitenbush Hot Springs, Oregon and the Wind River Valley, Washington. A total of 20 well, ...

  Citation × Citation Citation Abstract Copy Title: Geothermometry of Two Cascade Geothermal Systems Author: Malkemus, Donnel Alexander Year: 2016 For this thesis I applied classical and multi-component geothermometry techniques to new water chemistry data from Breitenbush Hot Springs, Oregon and the Wind River Valley, Washington. A total of 20 well, spring, and stream samples from Breitenbush Hot Springs and 4 spring samples from the Wind River Valley were collected and analyzed for major, minor, and select trace anions and cations, as well as stable oxygen and hydrogen isotopes. I used two computer programs, GeoT and RTEst, to conduct multi-component geothermometry reservoir condition estimation on each water sample. Water chemistry data from Breitenbush Hot Springs indicates a range of thermal, nonthermal, and mixed waters in wells and springs. Isotope data from Breitenbush Hot Springs indicates that thermal water is a mix between "andesitic waters" (6-10%) and meteoric water (90-94%) from the crest of the Oregon Cascades. Classical and multi-component geothermometry conducted for Breitenbush samples for this thesis suggest a reservoir temperature of approximately 137º C, which is close to the bottom hole temperature recorded in the nearby 2,457 meter deep SUNEDCO well of 141º C, but contrasts with previous applications of geothermometry which estimate a reservoir temperature between 170 and 180º C for the system. Reservoir estimates from this thesis for the Wind River Valley hot spring samples range from 80 to 100º C, which is consistent with previous studies. Multi-component geothermometry optimization indicates a loss of CO2 (i.e. degassing) during the water's ascent at both Breitenbush Hot Springs and the Wind River Valley, and that dilution from nonthermal water occurs in some samples from both areas. Multi-component geothermometry estimates were generally consistent between RTEst and GeoT; inconsistencies were primarily due to differences between the thermodynamic databases used for each program. Title: Geothermometry of Two Cascade Geothermal Systems Author: Malkemus, Donnel Alexander Year: 2016 For this thesis I applied classical and multi-component geothermometry techniques to new water chemistry data from Breitenbush Hot Springs, Oregon and the Wind River Valley, Washington. A total of 20 well, spring, and stream samples from Breitenbush Hot Springs and 4 spring samples from the Wind River Valley were collected and analyzed for major, minor, and select trace anions and cations, as well as stable oxygen and hydrogen isotopes. I used two computer programs, GeoT and RTEst, to conduct multi-component geothermometry reservoir condition estimation on each water sample. Water chemistry data from Breitenbush Hot Springs indicates a range of thermal, nonthermal, and mixed waters in wells and springs. Isotope data from Breitenbush Hot Springs indicates that thermal water is a mix between "andesitic waters" (6-10%) and meteoric water (90-94%) from the crest of the Oregon Cascades. Classical and multi-component geothermometry conducted for Breitenbush samples for this thesis suggest a reservoir temperature of approximately 137º C, which is close to the bottom hole temperature recorded in the nearby 2,457 meter deep SUNEDCO well of 141º C, but contrasts with previous applications of geothermometry which estimate a reservoir temperature between 170 and 180º C for the system. Reservoir estimates from this thesis for the Wind River Valley hot spring samples range from 80 to 100º C, which is consistent with previous studies. Multi-component geothermometry optimization indicates a loss of CO2 (i.e. degassing) during the water's ascent at both Breitenbush Hot Springs and the Wind River Valley, and that dilution from nonthermal water occurs in some samples from both areas. Multi-component geothermometry estimates were generally consistent between RTEst and GeoT; inconsistencies were primarily due to differences between the thermodynamic databases used for each program. Close

• 63. [Article] Reproductive Output of Mosses Under Experimental Warming on Fildes Peninsula, King George Island, Maritime Antarctica

  Background: Mosses dominate much of the vegetation in the Antarctic, but the effect of climatic change on moss growth and sexual reproduction has scarcely been studied. In Antarctica, mosses infrequently ...

  Citation × Citation Citation Abstract Copy Title: Reproductive Output of Mosses Under Experimental Warming on Fildes Peninsula, King George Island, Maritime Antarctica Author: Casanova-Katny, Angélica, Torres-Mellado, G. A., Eppley, Sarah M. Year: 2016 Background: Mosses dominate much of the vegetation in the Antarctic, but the effect of climatic change on moss growth and sexual reproduction has scarcely been studied. In Antarctica, mosses infrequently produce sporophytes; whether this is due to physiological limitation or an adaptive response is unknown. We studied the effect of experimental warming (with Open Top Chambers, OTCs) on sporophyte production on Fildes Peninsula, King George Island for four moss species (Bartramia patens, Hennediella antarctica, Polytrichastrum alpinum, and Sanionia georgicouncinata). To determine whether reducing cold stress increases sexual reproduction as would be predicted if sex is being constrained due to physiological limitations, we counted sporophytes for these four moss species in OTC and control plots during two years. Also, we measured sporophyte size for a smaller sample of sporophytes of two species, B. patens and H. antarctica, in the OTC and control plots. Results: After 2 years of the experimental treatment, maximum daily air temperature, but not daily mean air temperature, was significantly higher inside OTCs than outside. We found a significant species by treatment effect for sporophyte production, with more sporophytes produced in OTCs compared with controls for B. patens and P. alpinum. Also, sporophytes of B. patens and H. antarctica were significantly larger in the OTCs compared with the control plots. Conclusions: Our results suggest that the lack of sexual reproduction in these Antarctic mosses is not adaptive but is constrained by current environmental conditions and that ameliorating conditions, such as increased temperature may affect sexual reproduction in many Antarctic mosses, altering moss population genetics and dispersal patterns. Title: Reproductive Output of Mosses Under Experimental Warming on Fildes Peninsula, King George Island, Maritime Antarctica Author: Casanova-Katny, Angélica, Torres-Mellado, G. A., Eppley, Sarah M. Year: 2016 Background: Mosses dominate much of the vegetation in the Antarctic, but the effect of climatic change on moss growth and sexual reproduction has scarcely been studied. In Antarctica, mosses infrequently produce sporophytes; whether this is due to physiological limitation or an adaptive response is unknown. We studied the effect of experimental warming (with Open Top Chambers, OTCs) on sporophyte production on Fildes Peninsula, King George Island for four moss species (Bartramia patens, Hennediella antarctica, Polytrichastrum alpinum, and Sanionia georgicouncinata). To determine whether reducing cold stress increases sexual reproduction as would be predicted if sex is being constrained due to physiological limitations, we counted sporophytes for these four moss species in OTC and control plots during two years. Also, we measured sporophyte size for a smaller sample of sporophytes of two species, B. patens and H. antarctica, in the OTC and control plots. Results: After 2 years of the experimental treatment, maximum daily air temperature, but not daily mean air temperature, was significantly higher inside OTCs than outside. We found a significant species by treatment effect for sporophyte production, with more sporophytes produced in OTCs compared with controls for B. patens and P. alpinum. Also, sporophytes of B. patens and H. antarctica were significantly larger in the OTCs compared with the control plots. Conclusions: Our results suggest that the lack of sexual reproduction in these Antarctic mosses is not adaptive but is constrained by current environmental conditions and that ameliorating conditions, such as increased temperature may affect sexual reproduction in many Antarctic mosses, altering moss population genetics and dispersal patterns. Close

• 64. [Article] Differential Sensitivity to Climate Change of C and N Cycling Processes Across Soil Horizons in a Northern Hardwood Forest

  Climate of the northern hardwood forests of North America will become significantly warmer in the coming decades. Associated increases in soil temperature, decreases in water availability and changes in ...

  Citation × Citation Citation Abstract Copy Title: Differential Sensitivity to Climate Change of C and N Cycling Processes Across Soil Horizons in a Northern Hardwood Forest Author: Durán, Jorge, Morse, Jennifer L., Rodríguez, Alexandra, Campbell, John L. Year: 2017 Climate of the northern hardwood forests of North America will become significantly warmer in the coming decades. Associated increases in soil temperature, decreases in water availability and changes in winter snow pack and soil frost are likely to affect soil carbon (C) and nitrogen (N) cycling. Most studies of the effects of climate change on soil function have focused on the upper-organic part of the soil profile (e.g., forest floor), and little is known about effects on deeper mineral soil horizons. We exploited an elevation/orientation gradient at the Hubbard Brook Experimental Forest (New Hampshire, USA) to evaluate how variation in climate, similar to that projected to occur over the next 50–100 years, affects soil C and N pools and transformation rates in different soil horizons of northern hardwood forests. Lower elevation, south-facing plots with higher soil temperature, less soil moisture and snow, and increased frequency of soil freeze/thaw events had less soil inorganic N content and lower potential net N mineralization rates compared to higher elevation, north facing plots. These differences in N pools and fluxes were consistent for all soil horizons, but sensitivity to climate variation increased with soil depth, confirming that assessments of climate change effects that do not consider variation throughout the soil profile are likely to be incomplete and potentially inaccurate. Nitrogen cycling processes were more sensitive to climate variation than C cycling processes, suggesting a decoupling of C and N cycles in coming decades, with important implications for ecosystem function. Soil processes showed greater sensitivity to climate variation in summer than in spring, and in the warmer and less snowy year of sampling, suggesting that the effects of climate change might become more pronounced as temperatures increase and snow fall and water availability decrease in the coming decades. Title: Differential Sensitivity to Climate Change of C and N Cycling Processes Across Soil Horizons in a Northern Hardwood Forest Author: Durán, Jorge, Morse, Jennifer L., Rodríguez, Alexandra, Campbell, John L. Year: 2017 Climate of the northern hardwood forests of North America will become significantly warmer in the coming decades. Associated increases in soil temperature, decreases in water availability and changes in winter snow pack and soil frost are likely to affect soil carbon (C) and nitrogen (N) cycling. Most studies of the effects of climate change on soil function have focused on the upper-organic part of the soil profile (e.g., forest floor), and little is known about effects on deeper mineral soil horizons. We exploited an elevation/orientation gradient at the Hubbard Brook Experimental Forest (New Hampshire, USA) to evaluate how variation in climate, similar to that projected to occur over the next 50–100 years, affects soil C and N pools and transformation rates in different soil horizons of northern hardwood forests. Lower elevation, south-facing plots with higher soil temperature, less soil moisture and snow, and increased frequency of soil freeze/thaw events had less soil inorganic N content and lower potential net N mineralization rates compared to higher elevation, north facing plots. These differences in N pools and fluxes were consistent for all soil horizons, but sensitivity to climate variation increased with soil depth, confirming that assessments of climate change effects that do not consider variation throughout the soil profile are likely to be incomplete and potentially inaccurate. Nitrogen cycling processes were more sensitive to climate variation than C cycling processes, suggesting a decoupling of C and N cycles in coming decades, with important implications for ecosystem function. Soil processes showed greater sensitivity to climate variation in summer than in spring, and in the warmer and less snowy year of sampling, suggesting that the effects of climate change might become more pronounced as temperatures increase and snow fall and water availability decrease in the coming decades. Close

• 65. [Article] Spatial, Temporal and Frequency Based Climate change Assessment in Columbia River Basin Using Multi Downscaled-Scenarios

  Uncertainties in climate modelling are well documented in literature. Global Climate Models (GCMs) are often used to downscale the climatic parameters on a regional scale. In the present work, we have ...

  Citation × Citation Citation Abstract Copy Title: Spatial, Temporal and Frequency Based Climate change Assessment in Columbia River Basin Using Multi Downscaled-Scenarios Author: Rana, Arun, Moradkhani, Hamid Year: 2016 Uncertainties in climate modelling are well documented in literature. Global Climate Models (GCMs) are often used to downscale the climatic parameters on a regional scale. In the present work, we have analyzed the changes in precipitation and temperature for future scenario period of 2070–2099 with respect to historical period of 1970–2000 from statistically downscaled GCM projections in Columbia River Basin (CRB). Analysis is performed using two different statistically downscaled climate projections (with ten GCMs downscaled products each, for RCP 4.5 and RCP 8.5, from CMIP5 dataset) namely, those from the Bias Correction and Spatial Downscaling (BCSD) technique generated at Portland State University and from the Multivariate Adaptive Constructed Analogs (MACA) technique, generated at University of Idaho, totaling to 40 different scenarios. The two datasets for BCSD and MACA are downscaled from observed data for both scenarios projections i.e. RCP4.5 and RCP8.5. Analysis is performed using spatial change (yearly scale), temporal change (monthly scale), percentile change (seasonal scale), quantile change (yearly scale), and wavelet analysis (yearly scale) in the future period from the historical period, respectively, at a scale of 1/16th of degree for entire CRB region. Results have indicated in varied degree of spatial change pattern for the entire Columbia River Basin, especially western part of the basin. At temporal scales, winter precipitation has higher variability than summer and vice versa for temperature. Most of the models have indicated considerate positive change in quantiles and percentiles for both precipitation and temperature. Wavelet analysis provided insights into possible explanation to changes in precipitation. Title: Spatial, Temporal and Frequency Based Climate change Assessment in Columbia River Basin Using Multi Downscaled-Scenarios Author: Rana, Arun, Moradkhani, Hamid Year: 2016 Uncertainties in climate modelling are well documented in literature. Global Climate Models (GCMs) are often used to downscale the climatic parameters on a regional scale. In the present work, we have analyzed the changes in precipitation and temperature for future scenario period of 2070–2099 with respect to historical period of 1970–2000 from statistically downscaled GCM projections in Columbia River Basin (CRB). Analysis is performed using two different statistically downscaled climate projections (with ten GCMs downscaled products each, for RCP 4.5 and RCP 8.5, from CMIP5 dataset) namely, those from the Bias Correction and Spatial Downscaling (BCSD) technique generated at Portland State University and from the Multivariate Adaptive Constructed Analogs (MACA) technique, generated at University of Idaho, totaling to 40 different scenarios. The two datasets for BCSD and MACA are downscaled from observed data for both scenarios projections i.e. RCP4.5 and RCP8.5. Analysis is performed using spatial change (yearly scale), temporal change (monthly scale), percentile change (seasonal scale), quantile change (yearly scale), and wavelet analysis (yearly scale) in the future period from the historical period, respectively, at a scale of 1/16th of degree for entire CRB region. Results have indicated in varied degree of spatial change pattern for the entire Columbia River Basin, especially western part of the basin. At temporal scales, winter precipitation has higher variability than summer and vice versa for temperature. Most of the models have indicated considerate positive change in quantiles and percentiles for both precipitation and temperature. Wavelet analysis provided insights into possible explanation to changes in precipitation. Close

• 66. [Article] Accounting For Downscaling and Model Uncertainty in Fine-Resolution Seasonal Climate Projections Over the Columbia River Basin

  Climate change is expected to have severe impacts on natural systems as well as various socio-economic aspects of human life. This has urged scientific communities to improve the understanding of future ...

  Citation × Citation Citation Abstract Copy Title: Accounting For Downscaling and Model Uncertainty in Fine-Resolution Seasonal Climate Projections Over the Columbia River Basin Author: Ahmadalipour, Ali, Moradkhani, Hamid, Rana, Arun Year: 2017 Climate change is expected to have severe impacts on natural systems as well as various socio-economic aspects of human life. This has urged scientific communities to improve the understanding of future climate and reduce the uncertainties associated with projections. In the present study, ten statistically downscaled CMIP5 GCMs at 1/16th deg. spatial resolution from two different downscaling procedures are utilized over the Columbia River Basin (CRB) to assess the changes in climate variables and characterize the associated uncertainties. Three climate variables, i.e. precipitation, maximum temperature, and minimum temperature, are studied for the historical period of 1970–2000 as well as future period of 2010–2099, simulated with representative concentration pathways of RCP4.5 and RCP8.5. Bayesian Model Averaging (BMA) is employed to reduce the model uncertainty and develop a probabilistic projection for each variable in each scenario. Historical comparison of long-term attributes of GCMs and observation suggests a more accurate representation for BMA than individual models. Furthermore, BMA projections are used to investigate future seasonal to annual changes of climate variables. Projections indicate significant increase in annual precipitation and temperature, with varied degree of change across different sub-basins of CRB. We then characterized uncertainty of future projections for each season over CRB. Results reveal that model uncertainty is the main source of uncertainty, among others. However, downscaling uncertainty considerably contributes to the total uncertainty of future projections, especially in summer. On the contrary, downscaling uncertainty appears to be higher than scenario uncertainty for precipitation. © 2017 Springer-Verlag Berlin Heidelberg Title: Accounting For Downscaling and Model Uncertainty in Fine-Resolution Seasonal Climate Projections Over the Columbia River Basin Author: Ahmadalipour, Ali, Moradkhani, Hamid, Rana, Arun Year: 2017 Climate change is expected to have severe impacts on natural systems as well as various socio-economic aspects of human life. This has urged scientific communities to improve the understanding of future climate and reduce the uncertainties associated with projections. In the present study, ten statistically downscaled CMIP5 GCMs at 1/16th deg. spatial resolution from two different downscaling procedures are utilized over the Columbia River Basin (CRB) to assess the changes in climate variables and characterize the associated uncertainties. Three climate variables, i.e. precipitation, maximum temperature, and minimum temperature, are studied for the historical period of 1970–2000 as well as future period of 2010–2099, simulated with representative concentration pathways of RCP4.5 and RCP8.5. Bayesian Model Averaging (BMA) is employed to reduce the model uncertainty and develop a probabilistic projection for each variable in each scenario. Historical comparison of long-term attributes of GCMs and observation suggests a more accurate representation for BMA than individual models. Furthermore, BMA projections are used to investigate future seasonal to annual changes of climate variables. Projections indicate significant increase in annual precipitation and temperature, with varied degree of change across different sub-basins of CRB. We then characterized uncertainty of future projections for each season over CRB. Results reveal that model uncertainty is the main source of uncertainty, among others. However, downscaling uncertainty considerably contributes to the total uncertainty of future projections, especially in summer. On the contrary, downscaling uncertainty appears to be higher than scenario uncertainty for precipitation. © 2017 Springer-Verlag Berlin Heidelberg Close

• 67. [Article] Variation in Tussock Architecture of the Invasive Cordgrass Spartina Densiflora along the Pacific Coast of North America

  Some introduced species spread rapidly beyond their native range and into novel habitats mediated by a high degree of phenotypic plasticity and/or rapid evolutionary responses. In this context, clonality ...

  Citation × Citation Citation Abstract Copy Title: Variation in Tussock Architecture of the Invasive Cordgrass Spartina Densiflora along the Pacific Coast of North America Author: Castillo, Jesus M., Grewall, Brenda J., Pickart, Andrea, Figueroa, Enrique, Sytsma, Mark D. Year: 2016 Some introduced species spread rapidly beyond their native range and into novel habitats mediated by a high degree of phenotypic plasticity and/or rapid evolutionary responses. In this context, clonality has been described as a significant factor contributing to invasiveness. We studied the abiotic environment and the responses of different tussock architecture traits of the invasive cordgrass Spartina densiflora Brongn. (Poaceae). A common garden experiment and field studies of S. densiflora in salt marshes across a wide latitudinal gradient from California (USA) to British Columbia (Canada) provided a model system for an integrated study of the potential mechanisms underlying the response of invasive S. densiflora populations to changes in environmental conditions. Our results showed that S. densiflora is able to adjust to widely variable climate (specifically, air temperature and the duration of the growing season) and sediment conditions (specifically, texture and hypoxia) through phenotypical plastic key functional tussock traits (e.g. shoot density, height, above- and below-ground biomass allocation patterns). Root biomass increased in coarser sediments in contrast to rhizomes, which were more abundant in finer sediments. Above-ground biomass and leaf area index increased mainly with air temperature during summer, and more robust (taller and wider) shoots were associated with more oxygenated sediments. In view of our results, S. densifloraappears to be a halophyte with a high degree of phenotypic plasticity that would enable it to respond successfully to changes in the abiotic conditions of salt marshes driven by global climate change, such as increasing salinity and temperatures. Title: Variation in Tussock Architecture of the Invasive Cordgrass Spartina Densiflora along the Pacific Coast of North America Author: Castillo, Jesus M., Grewall, Brenda J., Pickart, Andrea, Figueroa, Enrique, Sytsma, Mark D. Year: 2016 Some introduced species spread rapidly beyond their native range and into novel habitats mediated by a high degree of phenotypic plasticity and/or rapid evolutionary responses. In this context, clonality has been described as a significant factor contributing to invasiveness. We studied the abiotic environment and the responses of different tussock architecture traits of the invasive cordgrass Spartina densiflora Brongn. (Poaceae). A common garden experiment and field studies of S. densiflora in salt marshes across a wide latitudinal gradient from California (USA) to British Columbia (Canada) provided a model system for an integrated study of the potential mechanisms underlying the response of invasive S. densiflora populations to changes in environmental conditions. Our results showed that S. densiflora is able to adjust to widely variable climate (specifically, air temperature and the duration of the growing season) and sediment conditions (specifically, texture and hypoxia) through phenotypical plastic key functional tussock traits (e.g. shoot density, height, above- and below-ground biomass allocation patterns). Root biomass increased in coarser sediments in contrast to rhizomes, which were more abundant in finer sediments. Above-ground biomass and leaf area index increased mainly with air temperature during summer, and more robust (taller and wider) shoots were associated with more oxygenated sediments. In view of our results, S. densifloraappears to be a halophyte with a high degree of phenotypic plasticity that would enable it to respond successfully to changes in the abiotic conditions of salt marshes driven by global climate change, such as increasing salinity and temperatures. Close

• 68. [Article] Theoretical Study of Spin-wave Effects in Quantum Ferromagnets

  In this dissertation, we examine quantum ferromagnets and determine various effects of the magnetic Goldstone modes or "magnons'' in these systems. Firstly, we calculate the magnon contribution to the ...

  Citation × Citation Citation Abstract Copy Title: Theoretical Study of Spin-wave Effects in Quantum Ferromagnets Author: Bharadwaj, Sripoorna Paniyadi Krishna Year: 2017 In this dissertation, we examine quantum ferromagnets and determine various effects of the magnetic Goldstone modes or "magnons'' in these systems. Firstly, we calculate the magnon contribution to the transport relaxation rate of conduction electrons in metallic ferromagnets and find that at asymptotically low temperatures, the contribution behaves as T^2 exp(-T_0/T) and not as T^2 predicted previously. To perform these calculations, we derive and use a very general effective theory for metallic ferromagnets. This activation barrier-like behavior is due to the fact that spin waves only couple electrons from different Stoner subbands that arise from the splitting of the conduction band in presence of a nonzero magnetization. The T^2 behavior is found to be valid only in a pre-asymptotic temperature window. The temperature scale T_0 is the energy of the least energetic ferromagnon that couples electrons of different spins. Second, we discuss magnon-induced long-range correlation functions in quantum magnets. In the ordered phases of both classical ferromagnets and antiferromagnets, the long-range correlations induced by the magnons lead to a singular wavenumber dependence of the longitudinal order-parameter susceptibility in spatial dimensions 2<d<4. We investigate the quantum analog of this singularity using a nonlinear sigma model. In a quantum antiferromagnet at $T=0$, a weaker nonanalytic behavior is obtained, which is consistent with power counting. The analogous result for a quantum ferromagnet is absent if the magnon damping is neglected. This is due to the lack of magnon number fluctuations in the quantum ferromagnetic ground state. Magnon damping due to quenched disorder restores the expected nonanalyticity. Finally, we use an effective field theory for clean, strongly interacting electron systems to calculate the magnon contribution to the density of states, the longitudinal magnetic susceptibility and the conductivity in an itinerant ferromagnet. Utilizing a loop expansion that does not assume the electron-electron interaction to be a small parameter, we obtain the leading nonanalytic corrections to the Stoner saddle-point results for these observables, as functions of the frequency and wavenumber in the hydrodynamic limit. The dissertation includes previously published and unpublished co-authored material. Title: Theoretical Study of Spin-wave Effects in Quantum Ferromagnets Author: Bharadwaj, Sripoorna Paniyadi Krishna Year: 2017 In this dissertation, we examine quantum ferromagnets and determine various effects of the magnetic Goldstone modes or "magnons'' in these systems. Firstly, we calculate the magnon contribution to the transport relaxation rate of conduction electrons in metallic ferromagnets and find that at asymptotically low temperatures, the contribution behaves as T^2 exp(-T_0/T) and not as T^2 predicted previously. To perform these calculations, we derive and use a very general effective theory for metallic ferromagnets. This activation barrier-like behavior is due to the fact that spin waves only couple electrons from different Stoner subbands that arise from the splitting of the conduction band in presence of a nonzero magnetization. The T^2 behavior is found to be valid only in a pre-asymptotic temperature window. The temperature scale T_0 is the energy of the least energetic ferromagnon that couples electrons of different spins. Second, we discuss magnon-induced long-range correlation functions in quantum magnets. In the ordered phases of both classical ferromagnets and antiferromagnets, the long-range correlations induced by the magnons lead to a singular wavenumber dependence of the longitudinal order-parameter susceptibility in spatial dimensions 2<d<4. We investigate the quantum analog of this singularity using a nonlinear sigma model. In a quantum antiferromagnet at $T=0$, a weaker nonanalytic behavior is obtained, which is consistent with power counting. The analogous result for a quantum ferromagnet is absent if the magnon damping is neglected. This is due to the lack of magnon number fluctuations in the quantum ferromagnetic ground state. Magnon damping due to quenched disorder restores the expected nonanalyticity. Finally, we use an effective field theory for clean, strongly interacting electron systems to calculate the magnon contribution to the density of states, the longitudinal magnetic susceptibility and the conductivity in an itinerant ferromagnet. Utilizing a loop expansion that does not assume the electron-electron interaction to be a small parameter, we obtain the leading nonanalytic corrections to the Stoner saddle-point results for these observables, as functions of the frequency and wavenumber in the hydrodynamic limit. The dissertation includes previously published and unpublished co-authored material. Close

• 69. [Article] Modeling of Ultrafine Particle Emissions and Ambient Levels for the Near Roadside Environment

  Various epidemiological studies have linked exposure to Ultrafine Particles (UFP; diameter< 100 nm) to adverse health impacts. Roadway traffic is one of the major sources of UFPs and heavily influences ...

  Citation × Citation Citation Abstract Copy Title: Modeling of Ultrafine Particle Emissions and Ambient Levels for the Near Roadside Environment Author: Ahmed, Sauda Year: 2017 Various epidemiological studies have linked exposure to Ultrafine Particles (UFP; diameter< 100 nm) to adverse health impacts. Roadway traffic is one of the major sources of UFPs and heavily influences UFP concentrations in the nearby vicinity of major roadways. Modeling efforts to predict UFPs have been limited due to the scarcity of reliable information on emissions, lack of monitoring data and limited understanding of complex processes affecting UFP concentrations near sources. In this study continuous measurement of ultrafine particle number concentrations (PNC) and mass concentrations of nitric oxide (NO), nitrogen dioxide (NO2) and PM2.5 was conducted near an arterial road and freeway at different seasons and meteorological conditions and integrated with traffic count data. PNC showed high correlation with NO (r=0.64 for arterial; 0.61 for freeway), NO2 (r=0.57 for arterial; 0.53 for freeway) and NOx (NOx=NO+NO2; r=0.63 for arterial; 0.59 for freeway) and moderate to low correlation with traffic volume (r=0.33 for arterial; 0.32 for freeway) and PM2.5 (r=0.28 for arterial; 0.23 for freeway); respectively; for both sites at 15 minute averages. The PNC-NOx relationship prevailed on a shorter term (15 min), hourly, and throughout the day basis. Both PNC and NOx showed comparatively higher correlation with traffic during the morning period but became lower during evening which can be attributed to the higher boundary layer and wind speeds. The variable meteorology in the evening affects both PNC and NOx concentrations in the same way and the correlation between NOx and PNC is maintained high both during morning (r=0.74 for arterial; 0.69 for freeway), and evening (r=0.62 for arterial; 0.59 for freeway) periods. Thus nitrogen oxides can be used as a proxy for traffic-related UFP number concentration reflecting the effect of both traffic intensity and meteorological dilution. The PNC-NOx relation was explored for various meteorological parameters i.e. wind speed and temperature. It is found that NOx emission is temperature independent and can be used to reflect the effect of traffic intensity and meteorological dilution. Once the effect of traffic intensity and dilution is removed, the effect of temperature on PNC-NOx ratio becomes important which can be attributed to the variation in PNC emission factors with temperature. The high morning PNC-NOx ratio found at the arterial road is a result of new particle formation due to lower temperature and low concentration of exhaust gases in the morning air favoring nucleation over condensation. This finding has important implication when calculating emission factors for UFP number concentrations. Thus it can be concluded that roadside concentration of ultrafine particles not only depends on traffic intensity but also on meteorological parameters affecting dilution or new particle formation. High concentrations of ultrafine particle number concentration close to a roadway is expected due to higher traffic intensity , as well as during low wind speed causing low dilution and low temperature conditions favoring new particle formation. Finally a simplified approach of calculating particle number emission factor was developed using existing and easily available emission inventory for traffic related tracer gases. Using NOx emission factors from MOVES emission model, the emission ratio of PNC to NOx was converted to develop particle number emission factors. NOx was selected as the traffic related tracer gas since the number concentration of particles is closely correlated to NOx, NOx and particles are diluted in the same way and NOx emission factors are available for a variety of traffic situations. To ensure contribution of fresh traffic exhaust, the average of the difference of pollutant concentrations at high traffic condition and background condition was used to calculate PNC-NOX ratio. Using nitrogen oxides to define background and high-traffic conditions and MOVES emission factor for NOX to convert corresponding PNC-NOX ratio, an average emission factor of (1.82 ± 0.17) E+ 14 particle/ vehicle-km was obtained, suitable for summertime. When compared to existing particle number emission factors derived from dynamometer tests, it was found that there exits reasonable agreement between the calculated real world particle number emission factors and emission factors from dynamometer tests. The calculated emission factor and R-Line dispersion model was tested in predicting near-road particle number concentrations. Although only 23% of the variability in PNC was explained by the dispersion model, 84.33% of the measurements fell within the factor of two envelope. This suggests that there is potential to effectively use these models and thus warrants more in-depth analysis. Finally, a simple map of PNC gradients from major roads of Portland was developed. The results of this study helped identify proxy-indicators to provide reference values for estimating UFP concentrations and emissions that can be used for simple evaluation of particle concentration near major roadways for environmental and urban planning purposes and to assess expected impact of UFP pollution on population living near roadways exposed to elevated concentrations. Title: Modeling of Ultrafine Particle Emissions and Ambient Levels for the Near Roadside Environment Author: Ahmed, Sauda Year: 2017 Various epidemiological studies have linked exposure to Ultrafine Particles (UFP; diameter< 100 nm) to adverse health impacts. Roadway traffic is one of the major sources of UFPs and heavily influences UFP concentrations in the nearby vicinity of major roadways. Modeling efforts to predict UFPs have been limited due to the scarcity of reliable information on emissions, lack of monitoring data and limited understanding of complex processes affecting UFP concentrations near sources. In this study continuous measurement of ultrafine particle number concentrations (PNC) and mass concentrations of nitric oxide (NO), nitrogen dioxide (NO2) and PM2.5 was conducted near an arterial road and freeway at different seasons and meteorological conditions and integrated with traffic count data. PNC showed high correlation with NO (r=0.64 for arterial; 0.61 for freeway), NO2 (r=0.57 for arterial; 0.53 for freeway) and NOx (NOx=NO+NO2; r=0.63 for arterial; 0.59 for freeway) and moderate to low correlation with traffic volume (r=0.33 for arterial; 0.32 for freeway) and PM2.5 (r=0.28 for arterial; 0.23 for freeway); respectively; for both sites at 15 minute averages. The PNC-NOx relationship prevailed on a shorter term (15 min), hourly, and throughout the day basis. Both PNC and NOx showed comparatively higher correlation with traffic during the morning period but became lower during evening which can be attributed to the higher boundary layer and wind speeds. The variable meteorology in the evening affects both PNC and NOx concentrations in the same way and the correlation between NOx and PNC is maintained high both during morning (r=0.74 for arterial; 0.69 for freeway), and evening (r=0.62 for arterial; 0.59 for freeway) periods. Thus nitrogen oxides can be used as a proxy for traffic-related UFP number concentration reflecting the effect of both traffic intensity and meteorological dilution. The PNC-NOx relation was explored for various meteorological parameters i.e. wind speed and temperature. It is found that NOx emission is temperature independent and can be used to reflect the effect of traffic intensity and meteorological dilution. Once the effect of traffic intensity and dilution is removed, the effect of temperature on PNC-NOx ratio becomes important which can be attributed to the variation in PNC emission factors with temperature. The high morning PNC-NOx ratio found at the arterial road is a result of new particle formation due to lower temperature and low concentration of exhaust gases in the morning air favoring nucleation over condensation. This finding has important implication when calculating emission factors for UFP number concentrations. Thus it can be concluded that roadside concentration of ultrafine particles not only depends on traffic intensity but also on meteorological parameters affecting dilution or new particle formation. High concentrations of ultrafine particle number concentration close to a roadway is expected due to higher traffic intensity , as well as during low wind speed causing low dilution and low temperature conditions favoring new particle formation. Finally a simplified approach of calculating particle number emission factor was developed using existing and easily available emission inventory for traffic related tracer gases. Using NOx emission factors from MOVES emission model, the emission ratio of PNC to NOx was converted to develop particle number emission factors. NOx was selected as the traffic related tracer gas since the number concentration of particles is closely correlated to NOx, NOx and particles are diluted in the same way and NOx emission factors are available for a variety of traffic situations. To ensure contribution of fresh traffic exhaust, the average of the difference of pollutant concentrations at high traffic condition and background condition was used to calculate PNC-NOX ratio. Using nitrogen oxides to define background and high-traffic conditions and MOVES emission factor for NOX to convert corresponding PNC-NOX ratio, an average emission factor of (1.82 ± 0.17) E+ 14 particle/ vehicle-km was obtained, suitable for summertime. When compared to existing particle number emission factors derived from dynamometer tests, it was found that there exits reasonable agreement between the calculated real world particle number emission factors and emission factors from dynamometer tests. The calculated emission factor and R-Line dispersion model was tested in predicting near-road particle number concentrations. Although only 23% of the variability in PNC was explained by the dispersion model, 84.33% of the measurements fell within the factor of two envelope. This suggests that there is potential to effectively use these models and thus warrants more in-depth analysis. Finally, a simple map of PNC gradients from major roads of Portland was developed. The results of this study helped identify proxy-indicators to provide reference values for estimating UFP concentrations and emissions that can be used for simple evaluation of particle concentration near major roadways for environmental and urban planning purposes and to assess expected impact of UFP pollution on population living near roadways exposed to elevated concentrations. Close

• 70. [Article] Detection of Variable Retention Time in DRAM

  This thesis investigates a test method to detect the presence of Variable Retention Time (VRT) bits in manufactured DRAM. The VRT bits retention time is modeled as a 2-state random telegraph process that ...

  Citation × Citation Citation Abstract Copy Title: Detection of Variable Retention Time in DRAM Author: Kumar, Neraj Year: 2014 This thesis investigates a test method to detect the presence of Variable Retention Time (VRT) bits in manufactured DRAM. The VRT bits retention time is modeled as a 2-state random telegraph process that includes miscorrelation between test and use. The VRT defect is particularly sensitive to test and use conditions. A new test method is proposed to screen the VRT bits by simulating the use conditions during manufacturing test. Evaluation of the proposed test method required a bit-level VRT model to be parameterized as a function of temperature and voltage conditions. The complete 2-state VRT bit model combines models for the time-in-state and for the retention-time including miscorrelation. A copula is used to model the eect of miscorrelation between test and use. The proposed VRT test algorithm runtime is estimated as a function of VRT test coverage, test temperature and test voltage. Title: Detection of Variable Retention Time in DRAM Author: Kumar, Neraj Year: 2014 This thesis investigates a test method to detect the presence of Variable Retention Time (VRT) bits in manufactured DRAM. The VRT bits retention time is modeled as a 2-state random telegraph process that includes miscorrelation between test and use. The VRT defect is particularly sensitive to test and use conditions. A new test method is proposed to screen the VRT bits by simulating the use conditions during manufacturing test. Evaluation of the proposed test method required a bit-level VRT model to be parameterized as a function of temperature and voltage conditions. The complete 2-state VRT bit model combines models for the time-in-state and for the retention-time including miscorrelation. A copula is used to model the eect of miscorrelation between test and use. The proposed VRT test algorithm runtime is estimated as a function of VRT test coverage, test temperature and test voltage. Close

• 71. [Article] Partial Decarburization and Intensive Quenching to Increase Fatigue Limit of Quenched Small Parts

  The 5160 spring steel is mainly used to endure fatigue and since its Mf is below room temperature, retained austenite is usually present after conventional quenching, which is detrimental from a fatigue ...

  Citation × Citation Citation Abstract Copy Title: Partial Decarburization and Intensive Quenching to Increase Fatigue Limit of Quenched Small Parts Author: Lozano, Diego E., Totten, George E., Martínez Cázares, Gabriela M., Mercado-Solis, Rafael David Year: 2014 The 5160 spring steel is mainly used to endure fatigue and since its Mf is below room temperature, retained austenite is usually present after conventional quenching, which is detrimental from a fatigue point of view. To reduce the amount of retained austenite, a partial decarburization was promoted (to increase the Ms and Mf, respectively) by austenitizing the steel at different temperatures and times in air, prior to performing an interrupted quenching in an accelerated media (brine) instead of the conventional oil quenching. The same quenching conditions with partial decarburization and without decarburization are compared. In addition, conventional oil quenching was performed as reference. Results showed that with a controlled partial decarburization, it is possible to increase the fatigue limit compared to the conditions without decarburization (both interrupted quenching and oil quenching). Fatigue experiments were carried out in a rotating bending fatigue type tester. Cooling curves, decarburization profiles, fraction of martensite plots, and fatigue data are discussed. Title: Partial Decarburization and Intensive Quenching to Increase Fatigue Limit of Quenched Small Parts Author: Lozano, Diego E., Totten, George E., Martínez Cázares, Gabriela M., Mercado-Solis, Rafael David Year: 2014 The 5160 spring steel is mainly used to endure fatigue and since its Mf is below room temperature, retained austenite is usually present after conventional quenching, which is detrimental from a fatigue point of view. To reduce the amount of retained austenite, a partial decarburization was promoted (to increase the Ms and Mf, respectively) by austenitizing the steel at different temperatures and times in air, prior to performing an interrupted quenching in an accelerated media (brine) instead of the conventional oil quenching. The same quenching conditions with partial decarburization and without decarburization are compared. In addition, conventional oil quenching was performed as reference. Results showed that with a controlled partial decarburization, it is possible to increase the fatigue limit compared to the conditions without decarburization (both interrupted quenching and oil quenching). Fatigue experiments were carried out in a rotating bending fatigue type tester. Cooling curves, decarburization profiles, fraction of martensite plots, and fatigue data are discussed. Close

• 72. [Article] Predicted Stresses in Ball-Grid-Array (BGA) and Column-Grid-Array (CGA) Interconnections in a Mirror-Like Package Design

  There is an obvious incentive for using bow-free (temperature change insensitive) assemblies in various areas of engineering, including electron device and electronic packaging fields. The induced stresses ...

  Citation × Citation Citation Abstract Copy Title: Predicted Stresses in Ball-Grid-Array (BGA) and Column-Grid-Array (CGA) Interconnections in a Mirror-Like Package Design Author: Suhir, Ephraim, Ghaffarian, Reza, Nicolics, Johann Year: 2016 There is an obvious incentive for using bow-free (temperature change insensitive) assemblies in various areas of engineering, including electron device and electronic packaging fields. The induced stresses in a bow-free assembly could be, however, rather high, considerably higher than in an assembly, whose bow is not restricted. The simplest and trivial case of a bow-free assembly is a tri-component body, in which the inner component is sandwiched between two identical outer components (“mirror” structure), is addressed in our analysis, and a simple and physically meaningful analytical stress model is suggested. It is concluded that if acceptable stresses (below yield stress of the solder material) are achievable, a mirror (bow-free, temperature-change-insensitive) design should be preferred, because it results in an operationally stable performance of the system. Title: Predicted Stresses in Ball-Grid-Array (BGA) and Column-Grid-Array (CGA) Interconnections in a Mirror-Like Package Design Author: Suhir, Ephraim, Ghaffarian, Reza, Nicolics, Johann Year: 2016 There is an obvious incentive for using bow-free (temperature change insensitive) assemblies in various areas of engineering, including electron device and electronic packaging fields. The induced stresses in a bow-free assembly could be, however, rather high, considerably higher than in an assembly, whose bow is not restricted. The simplest and trivial case of a bow-free assembly is a tri-component body, in which the inner component is sandwiched between two identical outer components (“mirror” structure), is addressed in our analysis, and a simple and physically meaningful analytical stress model is suggested. It is concluded that if acceptable stresses (below yield stress of the solder material) are achievable, a mirror (bow-free, temperature-change-insensitive) design should be preferred, because it results in an operationally stable performance of the system. Close

• 73. [Article] 3D Hydrodynamic Model Development and Verification

  A three-dimensional numerical model was developed to simulate hydrodynamic, temperature, and water quality distributions in rivers and lakes. In an attempt to get rid of the extra approximation and complexity, ...

  Citation × Citation Citation Abstract Copy Title: 3D Hydrodynamic Model Development and Verification Author: Al-Zubaidi, Hussein A. M. Year: 2016 A three-dimensional numerical model was developed to simulate hydrodynamic, temperature, and water quality distributions in rivers and lakes. In an attempt to get rid of the extra approximation and complexity, no coordinate transformation has been done and z-coordinate system has been employed. The governing equations are the continuity equation, free surface equation, momentum equations, and conservation equations of temperature and water quality. The model employs the time splitting technique which allows splitting the directions in which we end with two-dimensional governing equations and eventually the solution ends with a tri-diagonal matrix, which is easily solved by Thomas algorithm. The first step after developing a numerical model and before adding more features or applying the model to a real case, the model should be verified. The verification of the model was done by implementing the model to known solutions test cases in additional to evaluating whether the code preserves fluid mass. A series of test cases is performed by comparing the model results with the analytical solutions as proposed by many modelers. The model showed good agreement between the analytical and the numerical solution. Title: 3D Hydrodynamic Model Development and Verification Author: Al-Zubaidi, Hussein A. M. Year: 2016 A three-dimensional numerical model was developed to simulate hydrodynamic, temperature, and water quality distributions in rivers and lakes. In an attempt to get rid of the extra approximation and complexity, no coordinate transformation has been done and z-coordinate system has been employed. The governing equations are the continuity equation, free surface equation, momentum equations, and conservation equations of temperature and water quality. The model employs the time splitting technique which allows splitting the directions in which we end with two-dimensional governing equations and eventually the solution ends with a tri-diagonal matrix, which is easily solved by Thomas algorithm. The first step after developing a numerical model and before adding more features or applying the model to a real case, the model should be verified. The verification of the model was done by implementing the model to known solutions test cases in additional to evaluating whether the code preserves fluid mass. A series of test cases is performed by comparing the model results with the analytical solutions as proposed by many modelers. The model showed good agreement between the analytical and the numerical solution. Close

• 74. [Article] Timing Vapor–Melt Equilibration in Silicic Magmas

  Magmas experiencing pressure changes can follow equilibrium or nonequilibrium degassing paths that determine the rate of gas exsolution and the composition of gases exsolved. Many variables influence timescales ...

  Citation × Citation Citation Abstract Copy Title: Timing Vapor–Melt Equilibration in Silicic Magmas Author: Ball, Madison Year: 2017 Magmas experiencing pressure changes can follow equilibrium or nonequilibrium degassing paths that determine the rate of gas exsolution and the composition of gases exsolved. Many variables influence timescales of equilibration between vapor and melt after a perturbation in pressure, temperature, or other factors, and the magnitude of this equilibration time determines whether the system experiences equilibrium degassing or not. In order to create a simplified framework for assessing degassing regime, we constructed a numerical diffusion model to test the sensitivity of equilibration time to variables such as bubble size, spacing, melt temperature, initial and final system pressures, and water content. We then determined the degassing regime for a range of bubble-spacing and decompression rates as an initial simplified framework to build on. We also attempted the first mixed-volatile continuous decompression experiments in order validate our model and further improve analyses and interpretations of volatile gradients in natural samples. Title: Timing Vapor–Melt Equilibration in Silicic Magmas Author: Ball, Madison Year: 2017 Magmas experiencing pressure changes can follow equilibrium or nonequilibrium degassing paths that determine the rate of gas exsolution and the composition of gases exsolved. Many variables influence timescales of equilibration between vapor and melt after a perturbation in pressure, temperature, or other factors, and the magnitude of this equilibration time determines whether the system experiences equilibrium degassing or not. In order to create a simplified framework for assessing degassing regime, we constructed a numerical diffusion model to test the sensitivity of equilibration time to variables such as bubble size, spacing, melt temperature, initial and final system pressures, and water content. We then determined the degassing regime for a range of bubble-spacing and decompression rates as an initial simplified framework to build on. We also attempted the first mixed-volatile continuous decompression experiments in order validate our model and further improve analyses and interpretations of volatile gradients in natural samples. Close

• 75. [Article] Ozone Reaction With Interior Building Materials: Influence of Diurnal Ozone Variation, Temperature and Humidity

  Elevated tropospheric ozone concentrations are associated with increased morbidity and mortality. Indoor ozone chemistry affects human exposure to ozone and reaction products that also may adversely affect ...

  Citation × Citation Citation Abstract Copy Title: Ozone Reaction With Interior Building Materials: Influence of Diurnal Ozone Variation, Temperature and Humidity Author: Rim, Donghyun, Gall, Elliot T., Maddalena, Randy L., Nazaroff, William W. Year: 2015 Elevated tropospheric ozone concentrations are associated with increased morbidity and mortality. Indoor ozone chemistry affects human exposure to ozone and reaction products that also may adversely affect health and comfort. Reactive uptake of ozone has been characterized for many building materials; however, scant information is available on how diurnal variation of ambient ozone influences ozone reaction with indoor surfaces. The primary objective of this study is to investigate ozone-surface reactions in response to a diurnally varying ozone exposure for three common building materials: ceiling tile, painted drywall, and carpet tile. A secondary objective is to examine the effects of air temperature and humidity. A third goal is to explore how conditioning of materials in an occupied office building might influence subsequent ozone-surface reactions. Experiments were performed at bench-scale with inlet ozone concentrations varied to simulate daytime (ozone elevated) and nighttime (ozone-free in these experiments) periods. To simulate office conditions, experiments were conducted at two temperatures (22 °C and 28 °C) and three relative humidity values (25%, 50%, 75%). Effects of indoor surface exposures were examined by placing material samples in an occupied office and repeating bench-scale characterization after exposure periods of 1 and 2 months. Deposition velocities were observed to be highest during the initial hour of ozone exposure with slow decrease in the subsequent hours of simulated daytime conditions. Daily-average ozone reaction probabilities for fresh materials are in the respective ranges of (1.7–2.7) × 10−5, (2.8–4.7) × 10−5, and (3.0–4.5) × 10−5 for ceiling tile, painted drywall, and carpet tile. The reaction probability decreases by 7%–47% across the three test materials after two 8-h periods of ozone exposure. Measurements with the samples from an occupied office reveal that deposition velocity can decrease or increase with time. Influence of temperature and humidity on ozone-surface reactivity was not strong. Title: Ozone Reaction With Interior Building Materials: Influence of Diurnal Ozone Variation, Temperature and Humidity Author: Rim, Donghyun, Gall, Elliot T., Maddalena, Randy L., Nazaroff, William W. Year: 2015 Elevated tropospheric ozone concentrations are associated with increased morbidity and mortality. Indoor ozone chemistry affects human exposure to ozone and reaction products that also may adversely affect health and comfort. Reactive uptake of ozone has been characterized for many building materials; however, scant information is available on how diurnal variation of ambient ozone influences ozone reaction with indoor surfaces. The primary objective of this study is to investigate ozone-surface reactions in response to a diurnally varying ozone exposure for three common building materials: ceiling tile, painted drywall, and carpet tile. A secondary objective is to examine the effects of air temperature and humidity. A third goal is to explore how conditioning of materials in an occupied office building might influence subsequent ozone-surface reactions. Experiments were performed at bench-scale with inlet ozone concentrations varied to simulate daytime (ozone elevated) and nighttime (ozone-free in these experiments) periods. To simulate office conditions, experiments were conducted at two temperatures (22 °C and 28 °C) and three relative humidity values (25%, 50%, 75%). Effects of indoor surface exposures were examined by placing material samples in an occupied office and repeating bench-scale characterization after exposure periods of 1 and 2 months. Deposition velocities were observed to be highest during the initial hour of ozone exposure with slow decrease in the subsequent hours of simulated daytime conditions. Daily-average ozone reaction probabilities for fresh materials are in the respective ranges of (1.7–2.7) × 10−5, (2.8–4.7) × 10−5, and (3.0–4.5) × 10−5 for ceiling tile, painted drywall, and carpet tile. The reaction probability decreases by 7%–47% across the three test materials after two 8-h periods of ozone exposure. Measurements with the samples from an occupied office reveal that deposition velocity can decrease or increase with time. Influence of temperature and humidity on ozone-surface reactivity was not strong. Close

• 76. [Article] Dendrochronology and Middle Miocene Petrified Oak: Modern Counterparts and Interpretation

  This study reports the first successful statistical crossdating among many ring width time series from petrified wood, thus providing a replicable continuous annual resolution window into tree growth and ...

  Citation × Citation Citation Abstract Copy Title: Dendrochronology and Middle Miocene Petrified Oak: Modern Counterparts and Interpretation Author: Wright, William E., Streck, Martin J., Baisan, Christopher, Wright, W. Walton, Szejner, Paul Year: 2015 This study reports the first successful statistical crossdating among many ring width time series from petrified wood, thus providing a replicable continuous annual resolution window into tree growth and environmental influences during the middle Miocene. The petrified samples, of the genus Quercus, originated at the Stinking Water (SW) locality in Oregon, a Miocene-aged exposure associated with the Columbia River Basalts. 40AR/39AR dating on pillow basalt from the locality yielded a weighted Plateau Age of 13.79 ±0.09 Ma placing the death of the trees at the end of the Langhian Stage of the Middle Miocene (15.97±0.05 to 13.65±0.05 Ma), during the middle Miocene Climate Transition (MMCT). Ring width time series from 26 radii, 17 different trees, show significant intercorrelation. A Modified Coexistence Approach was applied to determine the likely climate range when the SW trees were growing. The modified approach included regression of site-mean ring width time series statistic values on estimated soil moisture for the site locations, using site-mean data from 126 modern Quercus sites from across the United States. Identification of highly significant linearities indicated strong relationships between ring width intercorrelation and soil moisture and ring width variability and soil moisture. Comparison of individual modern site-mean statistical values with values calculated for the SW locality suggests a mesic growing environment for the SW Quercus, with moderate temperatures. Geographic placement of modern Quercus sites with site-mean statistics similar to the SW values indicates a modern analogue in the eastern United States. Modern distributions of mesic species in the genera present at the SW locality suggest similarities with the central and southern Appalachian Mountains and the Ozark/Ouachita Mountains, indicating a mean annual temperature range of between ring width intercorrelation and soil moisture and ring width variability and soil moisture. Comparison of individual modern site-mean statistical values with values calculated for the SW locality suggests a mesic growing environment for the SW Quercus, with moderate temperatures. Geographic placement of modern Quercus sites with site-mean statistics similar to the SW values indicates a modern analogue in the eastern United States. Modern distributions of mesic species in the genera present at the SW locality suggest similarities with the central and southern Appalachian Mountains and the Ozark/Ouachita Mountains, indicating a mean annual temperature range of ≅10 ˚C to ≅ 15 ˚C and a mean annual precipitation range of ≅750 mm to ≅1200 mm when the SW Quercus were growing. Title: Dendrochronology and Middle Miocene Petrified Oak: Modern Counterparts and Interpretation Author: Wright, William E., Streck, Martin J., Baisan, Christopher, Wright, W. Walton, Szejner, Paul Year: 2015 This study reports the first successful statistical crossdating among many ring width time series from petrified wood, thus providing a replicable continuous annual resolution window into tree growth and environmental influences during the middle Miocene. The petrified samples, of the genus Quercus, originated at the Stinking Water (SW) locality in Oregon, a Miocene-aged exposure associated with the Columbia River Basalts. 40AR/39AR dating on pillow basalt from the locality yielded a weighted Plateau Age of 13.79 ±0.09 Ma placing the death of the trees at the end of the Langhian Stage of the Middle Miocene (15.97±0.05 to 13.65±0.05 Ma), during the middle Miocene Climate Transition (MMCT). Ring width time series from 26 radii, 17 different trees, show significant intercorrelation. A Modified Coexistence Approach was applied to determine the likely climate range when the SW trees were growing. The modified approach included regression of site-mean ring width time series statistic values on estimated soil moisture for the site locations, using site-mean data from 126 modern Quercus sites from across the United States. Identification of highly significant linearities indicated strong relationships between ring width intercorrelation and soil moisture and ring width variability and soil moisture. Comparison of individual modern site-mean statistical values with values calculated for the SW locality suggests a mesic growing environment for the SW Quercus, with moderate temperatures. Geographic placement of modern Quercus sites with site-mean statistics similar to the SW values indicates a modern analogue in the eastern United States. Modern distributions of mesic species in the genera present at the SW locality suggest similarities with the central and southern Appalachian Mountains and the Ozark/Ouachita Mountains, indicating a mean annual temperature range of between ring width intercorrelation and soil moisture and ring width variability and soil moisture. Comparison of individual modern site-mean statistical values with values calculated for the SW locality suggests a mesic growing environment for the SW Quercus, with moderate temperatures. Geographic placement of modern Quercus sites with site-mean statistics similar to the SW values indicates a modern analogue in the eastern United States. Modern distributions of mesic species in the genera present at the SW locality suggest similarities with the central and southern Appalachian Mountains and the Ozark/Ouachita Mountains, indicating a mean annual temperature range of ≅10 ˚C to ≅ 15 ˚C and a mean annual precipitation range of ≅750 mm to ≅1200 mm when the SW Quercus were growing. Close

• 77. [Article] THE EFFECT OF A PATENT FORAMEN OVALE ON THERMOREGULATORY AND VENTILATORY RESPONSES DURING PASSIVE HEATING AND COOLING

  41 pages. A thesis presented to the Department of Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, ...

  Citation × Citation Citation Abstract Copy Title: THE EFFECT OF A PATENT FORAMEN OVALE ON THERMOREGULATORY AND VENTILATORY RESPONSES DURING PASSIVE HEATING AND COOLING Author: Hay, Madeline Year: 2016 41 pages. A thesis presented to the Department of Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2016. Title: THE EFFECT OF A PATENT FORAMEN OVALE ON THERMOREGULATORY AND VENTILATORY RESPONSES DURING PASSIVE HEATING AND COOLING Author: Hay, Madeline Year: 2016 41 pages. A thesis presented to the Department of Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2016. Close

• 78. [Article] Application of Paleoenvironmental Data for Testing Climate Models and Understanding Past and Future Climate Variations

  Paleo data-model comparison is the process of comparing output from model simulations of past periods with paleoenvironmental data. It enables us to understand both the paleoclimate mechanism and responses ...

  Citation × Citation Citation Abstract Copy Title: Application of Paleoenvironmental Data for Testing Climate Models and Understanding Past and Future Climate Variations Author: Izumi, Kenji Year: 2014 Paleo data-model comparison is the process of comparing output from model simulations of past periods with paleoenvironmental data. It enables us to understand both the paleoclimate mechanism and responses of the earth environment to the climate and to evaluate how models work. This dissertation has two parts that each involve the development and application of approaches for data-model comparisons. In part 1, which is focused on the understanding of both past and future climatic changes/variations, I compare paleoclimate and historical simulations with future climate projections exploiting the fact that climate-model configurations are exactly the same in the paleo and future simulations in the Coupled Model Intercomparison Project Phase 5. In practice, I investigated large-scale temperature responses (land-ocean contrast, high-latitude amplification, and change in temperature seasonality) in paleo and future simulations, found broadly consistent relationships across the climate states, and validated the responses using modern observations and paleoclimate reconstructions. Furthermore, I examined the possibility that a small set of common mechanisms controls the large-scale temperature responses using a simple energy-balance model to decompose the temperature changes shown in warm and cold climate simulations and found that the clear-sky longwave downward radiation is a key control of the robust responses. In part 2, I applied the equilibrium terrestrial biosphere models, BIOME4 and BIOME5 (developed from BIOME4 herein), for reconstructing paleoclimate. I applied inverse modeling through the iterative forward-modeling (IMIFM) approach that uses the North American vegetation data to infer the mid-Holocene (MH, 6000 years ago) and the Last Glacial Maximum (LGM, 21,000 years ago) climates that control vegetation distributions. The IMIFM approach has the potential to provide more accurate quantitative climate estimates from pollen records than statistical approaches. Reconstructed North American MH and LGM climate anomaly patterns are coherent and consistent between variables and between BIOME4 and BIOME5, and these patterns are also consistent with previous data synthesis. This dissertation includes previously published and unpublished coauthored material. Title: Application of Paleoenvironmental Data for Testing Climate Models and Understanding Past and Future Climate Variations Author: Izumi, Kenji Year: 2014 Paleo data-model comparison is the process of comparing output from model simulations of past periods with paleoenvironmental data. It enables us to understand both the paleoclimate mechanism and responses of the earth environment to the climate and to evaluate how models work. This dissertation has two parts that each involve the development and application of approaches for data-model comparisons. In part 1, which is focused on the understanding of both past and future climatic changes/variations, I compare paleoclimate and historical simulations with future climate projections exploiting the fact that climate-model configurations are exactly the same in the paleo and future simulations in the Coupled Model Intercomparison Project Phase 5. In practice, I investigated large-scale temperature responses (land-ocean contrast, high-latitude amplification, and change in temperature seasonality) in paleo and future simulations, found broadly consistent relationships across the climate states, and validated the responses using modern observations and paleoclimate reconstructions. Furthermore, I examined the possibility that a small set of common mechanisms controls the large-scale temperature responses using a simple energy-balance model to decompose the temperature changes shown in warm and cold climate simulations and found that the clear-sky longwave downward radiation is a key control of the robust responses. In part 2, I applied the equilibrium terrestrial biosphere models, BIOME4 and BIOME5 (developed from BIOME4 herein), for reconstructing paleoclimate. I applied inverse modeling through the iterative forward-modeling (IMIFM) approach that uses the North American vegetation data to infer the mid-Holocene (MH, 6000 years ago) and the Last Glacial Maximum (LGM, 21,000 years ago) climates that control vegetation distributions. The IMIFM approach has the potential to provide more accurate quantitative climate estimates from pollen records than statistical approaches. Reconstructed North American MH and LGM climate anomaly patterns are coherent and consistent between variables and between BIOME4 and BIOME5, and these patterns are also consistent with previous data synthesis. This dissertation includes previously published and unpublished coauthored material. Close

• 79. [Article] Household Water Demand and Land Use Context: A Multilevel Approach

  Urban water use arises from a mix of scale-dependent biophysical and socioeconomic factors. In Portland, Oregon, single-family residential water use exhibits a tightly coupled relationship with summertime ...

  Citation × Citation Citation Abstract Copy Title: Household Water Demand and Land Use Context: A Multilevel Approach Author: Breyer, Elizabeth Yancey Year: 2014 Urban water use arises from a mix of scale-dependent biophysical and socioeconomic factors. In Portland, Oregon, single-family residential water use exhibits a tightly coupled relationship with summertime weather, although this relationship varies with land use patterns across households and neighborhoods. This thesis developed a multilevel regression model to evaluate the relative importance of weather variability, parcel land use characteristics, and neighborhood geographic context in explaining single-family residential water demand patterns in the Portland metropolitan area. The model drew on a high-resolution panel dataset of weekly mean summer water use over five years (2001-2005) for a sample of 460 single-family households spanning an urban-to-suburban gradient. Water use was found to be most elastic with respect to parcel-scale building size. Building age was negatively related to water use at both the parcel and neighborhood scale. Half the variation in water use can be attributed to between-household factors. Between-neighborhood variation exerted a modest but statistically significant effect. The analysis decomposed household temperature sensitivity into four components: a fixed effect common to all households, a household-specific deviation from the fixed effect, a separate extreme heat effect, and a land use effect, where lot size exaggerated the effect of temperature on water use. Results suggested that land use planning may be an effective non-price mechanism for long-range management of peak demand, as land use decisions have water use implications. The combined effects of population growth, urbanization, and climate change expose water providers to risk of water stress. Modeling fine-grain relationships among heat, land use, and water use across scales plays a role in long-range climate change planning and adaptation. Title: Household Water Demand and Land Use Context: A Multilevel Approach Author: Breyer, Elizabeth Yancey Year: 2014 Urban water use arises from a mix of scale-dependent biophysical and socioeconomic factors. In Portland, Oregon, single-family residential water use exhibits a tightly coupled relationship with summertime weather, although this relationship varies with land use patterns across households and neighborhoods. This thesis developed a multilevel regression model to evaluate the relative importance of weather variability, parcel land use characteristics, and neighborhood geographic context in explaining single-family residential water demand patterns in the Portland metropolitan area. The model drew on a high-resolution panel dataset of weekly mean summer water use over five years (2001-2005) for a sample of 460 single-family households spanning an urban-to-suburban gradient. Water use was found to be most elastic with respect to parcel-scale building size. Building age was negatively related to water use at both the parcel and neighborhood scale. Half the variation in water use can be attributed to between-household factors. Between-neighborhood variation exerted a modest but statistically significant effect. The analysis decomposed household temperature sensitivity into four components: a fixed effect common to all households, a household-specific deviation from the fixed effect, a separate extreme heat effect, and a land use effect, where lot size exaggerated the effect of temperature on water use. Results suggested that land use planning may be an effective non-price mechanism for long-range management of peak demand, as land use decisions have water use implications. The combined effects of population growth, urbanization, and climate change expose water providers to risk of water stress. Modeling fine-grain relationships among heat, land use, and water use across scales plays a role in long-range climate change planning and adaptation. Close

• 80. [Article] Modeling the Impact of Water Quality and Food Web Structure on Bull Trout in Two Washington Reservoirs

  Mechanistic models of the hydrodynamics and water quality were developed for Lake Kachess and Lake Keechelus in the Yakima River basin of Eastern Washington. These models were coupled to a fish bioenergetics ...

  Citation × Citation Citation Abstract Copy Title: Modeling the Impact of Water Quality and Food Web Structure on Bull Trout in Two Washington Reservoirs Author: Berger, Chris J., Wells, Scott A. Year: 2017 Mechanistic models of the hydrodynamics and water quality were developed for Lake Kachess and Lake Keechelus in the Yakima River basin of Eastern Washington. These models were coupled to a fish bioenergetics model and used to explore management strategies to improve water quality in the reservoirs affecting kokanee production. The models were also applied to evaluate the impacts of the proposed implementation of the Kachess Drought Relief Pumping Plant (KDRPP) projects. The public domain model, CEQUAL-W2 Version 4 (Cole and Wells, 2016) was adapted to model the reservoirs. CEQUAL-W2 is a 2-dimensional (longitudinal-vertical) hydrodynamic and water quality model capable of predicting water surface, velocity, temperature, nutrients, multiple algae, zooplankton, periphyton, and macrophyte species, fish bioenergetics, sediment diagenesis, dissolved oxygen, pH, alkalinity, multiple CBOD groups, multiple suspended solids groups, multiple generic constituents (such as tracer, bacteria, toxics), and multiple organic matter groups, both dissolved and particulate. The model is set up to predict these state variables at longitudinal segments and vertical layers. Comparisons of field data to model predictions were made for water level, temperature, NH4-N, NO3-N, PO4-P, total N, Total P, total organic carbon, alkalinity, zooplankton, pH, chlorophyll a, and dissolved oxygen at multiple reservoir sites at various depths. Title: Modeling the Impact of Water Quality and Food Web Structure on Bull Trout in Two Washington Reservoirs Author: Berger, Chris J., Wells, Scott A. Year: 2017 Mechanistic models of the hydrodynamics and water quality were developed for Lake Kachess and Lake Keechelus in the Yakima River basin of Eastern Washington. These models were coupled to a fish bioenergetics model and used to explore management strategies to improve water quality in the reservoirs affecting kokanee production. The models were also applied to evaluate the impacts of the proposed implementation of the Kachess Drought Relief Pumping Plant (KDRPP) projects. The public domain model, CEQUAL-W2 Version 4 (Cole and Wells, 2016) was adapted to model the reservoirs. CEQUAL-W2 is a 2-dimensional (longitudinal-vertical) hydrodynamic and water quality model capable of predicting water surface, velocity, temperature, nutrients, multiple algae, zooplankton, periphyton, and macrophyte species, fish bioenergetics, sediment diagenesis, dissolved oxygen, pH, alkalinity, multiple CBOD groups, multiple suspended solids groups, multiple generic constituents (such as tracer, bacteria, toxics), and multiple organic matter groups, both dissolved and particulate. The model is set up to predict these state variables at longitudinal segments and vertical layers. Comparisons of field data to model predictions were made for water level, temperature, NH4-N, NO3-N, PO4-P, total N, Total P, total organic carbon, alkalinity, zooplankton, pH, chlorophyll a, and dissolved oxygen at multiple reservoir sites at various depths. Close

• 81. [Article] The Discovery and Development of Metal-Free Arylation Reactions with Unsymmetrical Diaryliodonium Salts

  Functionalizing arenes and heteroarenes has been an active area of research since the 19th century, due to the presence of these molecular structures in many industrially important sectors. A tremendous ...

  Citation × Citation Citation Abstract Copy Title: The Discovery and Development of Metal-Free Arylation Reactions with Unsymmetrical Diaryliodonium Salts Author: Sundalam, Sunil Kumar Year: 2017 Functionalizing arenes and heteroarenes has been an active area of research since the 19th century, due to the presence of these molecular structures in many industrially important sectors. A tremendous amount of research has been published in achieving these chemical transformations using stoichiometric reagents and transition metal-catalyzed reactions. However, challenges still remain. An alternative and comparable methodology to metal-catalyzed reactions to overcome the drawbacks will advance this particular area of research is desirable. Hypervalent iodine compounds offer a promising approach to metal-free arylation reactions. These mild, air and moisture stable compounds have showed significant success as non-toxic and metal-free reagents for the arylation reactions. In particular, unsymmetrical diaryliodonium salts offer functionalization of complex arene structure in an efficient and sustainable pathway. A base-mediated coupling reaction for the metal-free synthesis of alkyl-aryl ethers by using unsymmetrical diaryliodonium salts and aliphatic alcohols is described. This method shows broad substrate scope with respect to both of the coupling partners to produce industrially useful alkyl-aryl ethers in moderate to excellent yields. The reaction is operationally simple, proceeds at mild temperature, and is atom-economical. Sustainability and synthetic utility of this reaction is demonstrated by the use of unsymmetrical aryl(mesityl)iodonium salts as the arylating agents. A limitation of poor reactivity of electron rich unsymmetrical diaryliodonium salts was overcome by designing 2nd generation conditions and using trimethoxy benzene (TMP) as the auxiliary group. Additionally discovery and development of an efficient method to access highly functionalized arynes from unsymmetrical aryl(mesityl)iodonium tosylate salts is presented. The aryne intermediates are generated by ortho C-H deprotonation of aryl(mesityl)iodonium salt with an amide base and subsequently trapped in a cycloaddition reaction with furan in moderate to good yields. Selective iodonium moiety elimination is discussed and the effect of auxiliary and temperature to reduce the regioisomeric ratio is demonstrated. Finally, additional coupling partner including benzyl azide and aliphatic amines are presented to show further utility of this methodology. Also, mechanistic investigations leading to the moderate reactivity of some electron rich unsymmetrical diaryliodonium salts is discussed. Title: The Discovery and Development of Metal-Free Arylation Reactions with Unsymmetrical Diaryliodonium Salts Author: Sundalam, Sunil Kumar Year: 2017 Functionalizing arenes and heteroarenes has been an active area of research since the 19th century, due to the presence of these molecular structures in many industrially important sectors. A tremendous amount of research has been published in achieving these chemical transformations using stoichiometric reagents and transition metal-catalyzed reactions. However, challenges still remain. An alternative and comparable methodology to metal-catalyzed reactions to overcome the drawbacks will advance this particular area of research is desirable. Hypervalent iodine compounds offer a promising approach to metal-free arylation reactions. These mild, air and moisture stable compounds have showed significant success as non-toxic and metal-free reagents for the arylation reactions. In particular, unsymmetrical diaryliodonium salts offer functionalization of complex arene structure in an efficient and sustainable pathway. A base-mediated coupling reaction for the metal-free synthesis of alkyl-aryl ethers by using unsymmetrical diaryliodonium salts and aliphatic alcohols is described. This method shows broad substrate scope with respect to both of the coupling partners to produce industrially useful alkyl-aryl ethers in moderate to excellent yields. The reaction is operationally simple, proceeds at mild temperature, and is atom-economical. Sustainability and synthetic utility of this reaction is demonstrated by the use of unsymmetrical aryl(mesityl)iodonium salts as the arylating agents. A limitation of poor reactivity of electron rich unsymmetrical diaryliodonium salts was overcome by designing 2nd generation conditions and using trimethoxy benzene (TMP) as the auxiliary group. Additionally discovery and development of an efficient method to access highly functionalized arynes from unsymmetrical aryl(mesityl)iodonium tosylate salts is presented. The aryne intermediates are generated by ortho C-H deprotonation of aryl(mesityl)iodonium salt with an amide base and subsequently trapped in a cycloaddition reaction with furan in moderate to good yields. Selective iodonium moiety elimination is discussed and the effect of auxiliary and temperature to reduce the regioisomeric ratio is demonstrated. Finally, additional coupling partner including benzyl azide and aliphatic amines are presented to show further utility of this methodology. Also, mechanistic investigations leading to the moderate reactivity of some electron rich unsymmetrical diaryliodonium salts is discussed. Close

• 82. [Article] Detecting Change in Rainstorm Properties from 1977-2016 and Associated Future Flood Risks in Portland, Oregon

  In response to increased greenhouse gases and global temperatures, changes to the hydrologic cycle are projected to occur and new precipitation characteristics are expected to emerge. The study of these ...

  Citation × Citation Citation Abstract Copy Title: Detecting Change in Rainstorm Properties from 1977-2016 and Associated Future Flood Risks in Portland, Oregon Author: Cooley, Alexis Kirsten Year: 2017 In response to increased greenhouse gases and global temperatures, changes to the hydrologic cycle are projected to occur and new precipitation characteristics are expected to emerge. The study of these characteristics is facilitated by common indices to measure precipitation and temperature developed by the Expert Team on Climate Change Detection and Indices (ETCCDI). These indices can be used to describe the likely consequences of climate change such as increased daily precipitation intensity (SDII) and heavier rainfall events (R95p). This study calculates a subset of these indices from observed and modelled precipitation data in Portland, Oregon. Five rainfall gages from a high resolution rain gage network and projections from three downscaled global climate models including CanESM2, CESM1, CNRM-CM5 are used to calculate precipitation indices. Mann-Kendall's tau is used to detect monotonic trends in indices. The observational record is compared with models for the historic period (1977-2005) and these past trends are compared with projected future trends (2006-2100). The influence of study unit on trend detection is analyzed by computing trends at the annual and monthly scale. Study unit is show to be important for trend detection. When the annual study unit is used, projected future trends towards increased precipitation intensity and event volumes are not observed in the historic data. However, when analyzed with a monthly study unit, trends towards increased precipitation intensity and event volumes are observed in the historic data. These trends are shown to be important for Portland area flooding, as precipitation indices are shown to significantly correlate with 40 maximum peak flow events that occurred during the period of study. Title: Detecting Change in Rainstorm Properties from 1977-2016 and Associated Future Flood Risks in Portland, Oregon Author: Cooley, Alexis Kirsten Year: 2017 In response to increased greenhouse gases and global temperatures, changes to the hydrologic cycle are projected to occur and new precipitation characteristics are expected to emerge. The study of these characteristics is facilitated by common indices to measure precipitation and temperature developed by the Expert Team on Climate Change Detection and Indices (ETCCDI). These indices can be used to describe the likely consequences of climate change such as increased daily precipitation intensity (SDII) and heavier rainfall events (R95p). This study calculates a subset of these indices from observed and modelled precipitation data in Portland, Oregon. Five rainfall gages from a high resolution rain gage network and projections from three downscaled global climate models including CanESM2, CESM1, CNRM-CM5 are used to calculate precipitation indices. Mann-Kendall's tau is used to detect monotonic trends in indices. The observational record is compared with models for the historic period (1977-2005) and these past trends are compared with projected future trends (2006-2100). The influence of study unit on trend detection is analyzed by computing trends at the annual and monthly scale. Study unit is show to be important for trend detection. When the annual study unit is used, projected future trends towards increased precipitation intensity and event volumes are not observed in the historic data. However, when analyzed with a monthly study unit, trends towards increased precipitation intensity and event volumes are observed in the historic data. These trends are shown to be important for Portland area flooding, as precipitation indices are shown to significantly correlate with 40 maximum peak flow events that occurred during the period of study. Close

• 83. [Article] Melting in the Mantle Wedge: Quantifying the Effects of Crustal Morphology and Viscous Decoupling on Melt Production with Application to the Cascadia Subduction Zone

  Arc magmatism is sustained by the complex interactions between the subducting slab, the overriding plate, and the mantle wedge. Partial melting of mantle peridotite is achieved by fluid-induced flux melting ...

  Citation × Citation Citation Abstract Copy Title: Melting in the Mantle Wedge: Quantifying the Effects of Crustal Morphology and Viscous Decoupling on Melt Production with Application to the Cascadia Subduction Zone Author: Yang, Jiaming Year: 2017 Arc magmatism is sustained by the complex interactions between the subducting slab, the overriding plate, and the mantle wedge. Partial melting of mantle peridotite is achieved by fluid-induced flux melting and decompression melting due to upward flow. The distribution of melting is sensitive to temperature, the pattern of flow, and the pressure in the mantle wedge. The arc front is the surface manifestation of partial melting in the mantle wedge and is characterized by a narrow chain of active volcanoes that migrate in time. The conventional interpretation is that changes in slab dip angle lead to changes in the arc front position relative to the trench. We explore an alternative hypothesis: evolution of the overlying plate, specifically thickening of the arc root, causes arc front migration. We investigate the effects of varying crustal morphology and viscous decoupling of the shallow slab-mantle interface on melt production using 2D numerical models involving a stationary overriding plate, a subducting plate with prescribed motion, and a dynamic mantle wedge. Melt production is quantified using a hydrous melting parameterization. We conclude: 1) Localized lithospheric thickening shifts the locus of melt production trenchward while thinning shifts melting landward. 2) Inclined LAB topography modulates the asthenospheric flow field, producing a narrow, well-defined arc front. 3) Thickening of the overriding plate exerts increased torque on the slab, favoring shallowing of the dip angle. 4) Viscous decoupling produces a cold, stagnant forearc mantle but promotes arc front melting due to reduction in the radius of corner flow, leading to higher temperatures at the coupling/decoupling transition. Title: Melting in the Mantle Wedge: Quantifying the Effects of Crustal Morphology and Viscous Decoupling on Melt Production with Application to the Cascadia Subduction Zone Author: Yang, Jiaming Year: 2017 Arc magmatism is sustained by the complex interactions between the subducting slab, the overriding plate, and the mantle wedge. Partial melting of mantle peridotite is achieved by fluid-induced flux melting and decompression melting due to upward flow. The distribution of melting is sensitive to temperature, the pattern of flow, and the pressure in the mantle wedge. The arc front is the surface manifestation of partial melting in the mantle wedge and is characterized by a narrow chain of active volcanoes that migrate in time. The conventional interpretation is that changes in slab dip angle lead to changes in the arc front position relative to the trench. We explore an alternative hypothesis: evolution of the overlying plate, specifically thickening of the arc root, causes arc front migration. We investigate the effects of varying crustal morphology and viscous decoupling of the shallow slab-mantle interface on melt production using 2D numerical models involving a stationary overriding plate, a subducting plate with prescribed motion, and a dynamic mantle wedge. Melt production is quantified using a hydrous melting parameterization. We conclude: 1) Localized lithospheric thickening shifts the locus of melt production trenchward while thinning shifts melting landward. 2) Inclined LAB topography modulates the asthenospheric flow field, producing a narrow, well-defined arc front. 3) Thickening of the overriding plate exerts increased torque on the slab, favoring shallowing of the dip angle. 4) Viscous decoupling produces a cold, stagnant forearc mantle but promotes arc front melting due to reduction in the radius of corner flow, leading to higher temperatures at the coupling/decoupling transition. Close

• 84. [Article] Oregon Lake Watch, 2015 Annual Report

  The Oregon Lake Watch (OLW) volunteer monitoring program completed its third year of operation during 2015 with a focus on early detection of aquatic invasive species (AIS) and water quality status and ...

  Citation × Citation Citation Abstract Copy Title: Oregon Lake Watch, 2015 Annual Report Author: Cimino, Samuel, Miller, Rich, Strecker, Angela L. Year: 2015 The Oregon Lake Watch (OLW) volunteer monitoring program completed its third year of operation during 2015 with a focus on early detection of aquatic invasive species (AIS) and water quality status and trend assessments for the better management of Oregon’s lakes and reservoirs. AIS surveys emphasized the detection of Watch List aquatic plant and species that can have a negative impacts on the beneficial uses of our waterbodies. Water transparency and temperature measurements were used to track the condition of volunteers' lakes. Thirty-one Oregon lakes have been surveyed during the OLW’s three years, 16 of which were surveyed during 2015. Seven lakes have been surveyed all three years and seven more have been surveyed two of the three years. Four Watch List plant and one animal species were found during 2015. Eurasian watermilfoil (Myriophyllum spicatum) was found in three lakes, Brazilian elodea (Egeria densa) and curly leaf pondweed (Potamogeton crispus) were each found in two lakes, and yellow flag iris (Iris pseudacorus) was found in one lake. Asian clams (Corbicula fluminea) were found in one lake. A diverse array of native plants were found along with native signal crayfish (Pacifasticus leniusculus). Water quality ranged from eutrophic to oligotrophic conditions based on water transparency and water temperatures ranged as high as 28°C (82°F). More years of data collection are necessary to track water quality trends. Title: Oregon Lake Watch, 2015 Annual Report Author: Cimino, Samuel, Miller, Rich, Strecker, Angela L. Year: 2015 The Oregon Lake Watch (OLW) volunteer monitoring program completed its third year of operation during 2015 with a focus on early detection of aquatic invasive species (AIS) and water quality status and trend assessments for the better management of Oregon’s lakes and reservoirs. AIS surveys emphasized the detection of Watch List aquatic plant and species that can have a negative impacts on the beneficial uses of our waterbodies. Water transparency and temperature measurements were used to track the condition of volunteers' lakes. Thirty-one Oregon lakes have been surveyed during the OLW’s three years, 16 of which were surveyed during 2015. Seven lakes have been surveyed all three years and seven more have been surveyed two of the three years. Four Watch List plant and one animal species were found during 2015. Eurasian watermilfoil (Myriophyllum spicatum) was found in three lakes, Brazilian elodea (Egeria densa) and curly leaf pondweed (Potamogeton crispus) were each found in two lakes, and yellow flag iris (Iris pseudacorus) was found in one lake. Asian clams (Corbicula fluminea) were found in one lake. A diverse array of native plants were found along with native signal crayfish (Pacifasticus leniusculus). Water quality ranged from eutrophic to oligotrophic conditions based on water transparency and water temperatures ranged as high as 28°C (82°F). More years of data collection are necessary to track water quality trends. Close

• 85. [Article] Automatic Calibration of Water Quality and Hydrodynamic Model (CE-QUAL-W2)

  One of the most important purposes of surface water resource management is to develop predictive models to assist in identifying and evaluating operational and structural measures for improving water quality. ...

  Citation × Citation Citation Abstract Copy Title: Automatic Calibration of Water Quality and Hydrodynamic Model (CE-QUAL-W2) Author: Shojaei, Nasim Year: 2014 One of the most important purposes of surface water resource management is to develop predictive models to assist in identifying and evaluating operational and structural measures for improving water quality. To better understand the effects of external and internal nutrient and organic loading and the effects of reservoir operation, a model is often developed, calibrated, and used for sensitivity and management simulations. The importance of modeling and simulation in the scientific community has drawn interest towards methods for automated calibration. This study addresses using an automatic technique to calibrate the water quality model CE-QUAL-W2 (Cole and Wells, 2013). CE-QUAL-W2 is a two-dimensional (2D) longitudinal/vertical hydrodynamic and water quality model for surface water bodies, modeling eutrophication processes such as temperature-nutrient-algae-dissolved oxygen-organic matter and sediment relationships. The numerical method used for calibration in this study is the particle swarm optimization method developed by Kennedy and Eberhart (1995) and inspired by the paradigm of birds flocking. The objective of this calibration procedure is to choose model parameters and coefficients affecting temperature, chlorophyll a, dissolved oxygen, and nutrients (such as NH4, NO3, and PO4). A case study is presented for the Karkheh Reservoir in Iran with a capacity of more than 5 billion cubic meters that is the largest dam in Iran with both agricultural and drinking water usages. This algorithm is shown to perform very well for determining model parameters for the reservoir water quality and hydrodynamic model. Implications of the use of this procedure for other water quality models are also shown. Title: Automatic Calibration of Water Quality and Hydrodynamic Model (CE-QUAL-W2) Author: Shojaei, Nasim Year: 2014 One of the most important purposes of surface water resource management is to develop predictive models to assist in identifying and evaluating operational and structural measures for improving water quality. To better understand the effects of external and internal nutrient and organic loading and the effects of reservoir operation, a model is often developed, calibrated, and used for sensitivity and management simulations. The importance of modeling and simulation in the scientific community has drawn interest towards methods for automated calibration. This study addresses using an automatic technique to calibrate the water quality model CE-QUAL-W2 (Cole and Wells, 2013). CE-QUAL-W2 is a two-dimensional (2D) longitudinal/vertical hydrodynamic and water quality model for surface water bodies, modeling eutrophication processes such as temperature-nutrient-algae-dissolved oxygen-organic matter and sediment relationships. The numerical method used for calibration in this study is the particle swarm optimization method developed by Kennedy and Eberhart (1995) and inspired by the paradigm of birds flocking. The objective of this calibration procedure is to choose model parameters and coefficients affecting temperature, chlorophyll a, dissolved oxygen, and nutrients (such as NH4, NO3, and PO4). A case study is presented for the Karkheh Reservoir in Iran with a capacity of more than 5 billion cubic meters that is the largest dam in Iran with both agricultural and drinking water usages. This algorithm is shown to perform very well for determining model parameters for the reservoir water quality and hydrodynamic model. Implications of the use of this procedure for other water quality models are also shown. Close

• 86. [Article] Distributed Modeling of Ablation (1996–2011) and Climate Sensitivity on the Glaciers of Taylor Valley, Antarctica

  The McMurdo Dry Valleys of Antarctica host the coldest and driest ecosystem on Earth, which is acutely sensitive to the availability of water coming from glacial runoff. We modeled the spatial variability ...

  Citation × Citation Citation Abstract Copy Title: Distributed Modeling of Ablation (1996–2011) and Climate Sensitivity on the Glaciers of Taylor Valley, Antarctica Author: Hoffman, Matthew J., Fountain, Andrew G., Liston, Glen E. Year: 2016 The McMurdo Dry Valleys of Antarctica host the coldest and driest ecosystem on Earth, which is acutely sensitive to the availability of water coming from glacial runoff. We modeled the spatial variability in ablation and assessed climate sensitivity of the glacier ablation zones using 16 years of meteorological and surface mass-balance observations collected in Taylor Valley. Sublimation was the primary form of mass loss over much of the ablation zones, except for near the termini where melt, primarily below the surface, dominated. Microclimates in ~10 m scale topographic basins generated melt rates up to ten times higher than over smooth glacier surfaces. In contrast, the vertical terminal cliffs on the glaciers can have higher or lower melt rates than the horizontal surfaces due to differences in incoming solar radiation. The model systematically underpredicted ablation for the final 5 years studied, possibly due to an increase of windblown sediment. Surface mass-balance sensitivity to temperature was ~−0.02 m w.e. K−1, which is among the smallest magnitudes observed globally. We also identified a high sensitivity to ice albedo, with a decrease of 0.02 having similar effects as a 1 K increase in temperature, and a complex sensitivity to wind speed. Title: Distributed Modeling of Ablation (1996–2011) and Climate Sensitivity on the Glaciers of Taylor Valley, Antarctica Author: Hoffman, Matthew J., Fountain, Andrew G., Liston, Glen E. Year: 2016 The McMurdo Dry Valleys of Antarctica host the coldest and driest ecosystem on Earth, which is acutely sensitive to the availability of water coming from glacial runoff. We modeled the spatial variability in ablation and assessed climate sensitivity of the glacier ablation zones using 16 years of meteorological and surface mass-balance observations collected in Taylor Valley. Sublimation was the primary form of mass loss over much of the ablation zones, except for near the termini where melt, primarily below the surface, dominated. Microclimates in ~10 m scale topographic basins generated melt rates up to ten times higher than over smooth glacier surfaces. In contrast, the vertical terminal cliffs on the glaciers can have higher or lower melt rates than the horizontal surfaces due to differences in incoming solar radiation. The model systematically underpredicted ablation for the final 5 years studied, possibly due to an increase of windblown sediment. Surface mass-balance sensitivity to temperature was ~−0.02 m w.e. K−1, which is among the smallest magnitudes observed globally. We also identified a high sensitivity to ice albedo, with a decrease of 0.02 having similar effects as a 1 K increase in temperature, and a complex sensitivity to wind speed. Close

• 87. [Article] Winter Climate Change Affects Growing-Season Soil Microbial Biomass and Activity in Northern Hardwood Forests

  Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine ...

  Citation × Citation Citation Abstract Copy Title: Winter Climate Change Affects Growing-Season Soil Microbial Biomass and Activity in Northern Hardwood Forests Author: Durán, Jorge, Morse, Jennifer L., Groffman, Peter M., Campbell, John L., Christenson, Lynn M., Driscoll, Charles T., Fahey, Timothy J., Fisk, Melany C., Mitchell, Mryon J., Templer, Pamela H. Year: 2014 Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity during the growing season. Soils from lower elevation plots, which accumulated less snow and experienced more soil temperature variability during the winter (and likely more freeze/thaw events), had less extractable inorganic nitrogen (N), lower rates of microbial N production via potential net N mineralization and nitrification, and higher potential microbial respiration during the growing season. Potential nitrate production rates during the growing season were particularly sensitive to changes in winter snow pack accumulation and winter soil temperature variability, especially in spring. Effects of elevation and winter conditions on N transformation rates dif­ fered from those on potential microbial respiration, suggesting that N-related processes might respond differently to winter climate change in northern hardwood forests than C-related processes. Title: Winter Climate Change Affects Growing-Season Soil Microbial Biomass and Activity in Northern Hardwood Forests Author: Durán, Jorge, Morse, Jennifer L., Groffman, Peter M., Campbell, John L., Christenson, Lynn M., Driscoll, Charles T., Fahey, Timothy J., Fisk, Melany C., Mitchell, Mryon J., Templer, Pamela H. Year: 2014 Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity during the growing season. Soils from lower elevation plots, which accumulated less snow and experienced more soil temperature variability during the winter (and likely more freeze/thaw events), had less extractable inorganic nitrogen (N), lower rates of microbial N production via potential net N mineralization and nitrification, and higher potential microbial respiration during the growing season. Potential nitrate production rates during the growing season were particularly sensitive to changes in winter snow pack accumulation and winter soil temperature variability, especially in spring. Effects of elevation and winter conditions on N transformation rates dif­ fered from those on potential microbial respiration, suggesting that N-related processes might respond differently to winter climate change in northern hardwood forests than C-related processes. Close

• 88. [Article] Climate Change Decreases Nitrogen Pools and Mineralization Rates in Northern Hardwood Forests

  Nitrogen (N) supply often limits the productivity of temperate forests and is regulated by a complex mix of biological and climatic drivers. In excess, N is linked to a variety of soil, water, and air ...

  Citation × Citation Citation Abstract Copy Title: Climate Change Decreases Nitrogen Pools and Mineralization Rates in Northern Hardwood Forests Author: Durán, Jorge, Morse, Jennifer L., Groffman, Peter M., Campbell, John L., Christenson, Lynn M., Driscoll, Charles T., Fahey, Timothy J., Fisk, Melany C., Likens, Gene E., Melillo, Jerry M., Mitchell, Myron J., Templer, Pamela H., Vadeboncoeur, Matthew A. Year: 2016 Nitrogen (N) supply often limits the productivity of temperate forests and is regulated by a complex mix of biological and climatic drivers. In excess, N is linked to a variety of soil, water, and air pollution issues. Here, we use results from an elevation gradient study and historical data from the long-term Hubbard Brook Ecosystem Study (New Hampshire, USA) to examine relationships between changes in climate, especially during winter, and N supply to northern hardwood forest ecosystems. Low elevation plots with less snow, more soil freezing, and more freeze/thaw cycles supported lower rates of N mineralization than high elevation plots, despite having higher soil temperatures and no consistent differences in soil moisture during the growing season. These results are consistent with historical analyses showing decreases in rates of soil N mineralization and inorganic N concentrations since 1973 that are correlated with long-term increases in mean annual temperature, decreases in annual snow accumulation, and a increases in the number of winter thawing degree days. This evidence suggests that changing climate may be driving decreases in the availability of a key nutrient in northern hardwood forests, which could decrease ecosystem production but have positive effects on environmental consequences of excess N. Title: Climate Change Decreases Nitrogen Pools and Mineralization Rates in Northern Hardwood Forests Author: Durán, Jorge, Morse, Jennifer L., Groffman, Peter M., Campbell, John L., Christenson, Lynn M., Driscoll, Charles T., Fahey, Timothy J., Fisk, Melany C., Likens, Gene E., Melillo, Jerry M., Mitchell, Myron J., Templer, Pamela H., Vadeboncoeur, Matthew A. Year: 2016 Nitrogen (N) supply often limits the productivity of temperate forests and is regulated by a complex mix of biological and climatic drivers. In excess, N is linked to a variety of soil, water, and air pollution issues. Here, we use results from an elevation gradient study and historical data from the long-term Hubbard Brook Ecosystem Study (New Hampshire, USA) to examine relationships between changes in climate, especially during winter, and N supply to northern hardwood forest ecosystems. Low elevation plots with less snow, more soil freezing, and more freeze/thaw cycles supported lower rates of N mineralization than high elevation plots, despite having higher soil temperatures and no consistent differences in soil moisture during the growing season. These results are consistent with historical analyses showing decreases in rates of soil N mineralization and inorganic N concentrations since 1973 that are correlated with long-term increases in mean annual temperature, decreases in annual snow accumulation, and a increases in the number of winter thawing degree days. This evidence suggests that changing climate may be driving decreases in the availability of a key nutrient in northern hardwood forests, which could decrease ecosystem production but have positive effects on environmental consequences of excess N. Close

• 89. [Article] Lake Macroinvertebrate Assemblages and Relationship With Natural Environment and Tourism Stress in Jiuzhaigou Natural Reserve, China

  With increasing human population and urbanization, tourism in natural reserves and other protected lands is growing. It is critical to monitor and assess the impacts of tourism on ecosystem health. However, ...

  Citation × Citation Citation Abstract Copy Title: Lake Macroinvertebrate Assemblages and Relationship With Natural Environment and Tourism Stress in Jiuzhaigou Natural Reserve, China Author: Cao, Yong, Wang, Beixin, Zhang, Jie, Wang, Lizhu, Pan, Yangdong, Wang, Quanxi, Jian, Daijun, Deng, Guiping Year: 2016 With increasing human population and urbanization, tourism in natural reserves and other protected lands is growing. It is critical to monitor and assess the impacts of tourism on ecosystem health. However, there is a general lack of information on biological communities in natural reserves of developing countries and of tools for assessing human impacts. In the present study, we investigated macroinvertebrate assemblages in nine lakes in Jiuzhaigou Natural Reserve of China. Both benthic (20 dips of D-net) and light-trap samples (2 h) were collected at each lake and all benthic specimens and adults of Ephemeroptera, Plecoptera, and Trichoptera (EPT) were identified and counted. Water temperature and water quality variables were measured on site or in the Lab. Seventy taxa were recorded and dominated by dipterans and caddisflies. Light traps contributed 47% of taxa richness and 66% of EPT richness at the lakes. Detrended Correspondence Analysis showed that water temperature and tourism index were strongly associated with the changes of assemblage composition. Taxa richness and EPT richness calculated for the composite samples (benthic + light trap) were well fit with Poisson generalized linear model (adjusted R2 = 0.83 and 0.85, respectively), generally decreasing with increasing elevation, tourism index, and total-N. Tourism index was ranked as the top predictor for EPT richness based on multiple model weights, and elevation for taxa richness. In comparison, when based on benthic samples, neither of the metrics could be fitted with the seven environmental variables selected. These findings highlight the benefit of combined use of the sampling methods for lake monitoring and offered an analytical guide to developing biological indicators of lake ecosystem health in protected areas. Title: Lake Macroinvertebrate Assemblages and Relationship With Natural Environment and Tourism Stress in Jiuzhaigou Natural Reserve, China Author: Cao, Yong, Wang, Beixin, Zhang, Jie, Wang, Lizhu, Pan, Yangdong, Wang, Quanxi, Jian, Daijun, Deng, Guiping Year: 2016 With increasing human population and urbanization, tourism in natural reserves and other protected lands is growing. It is critical to monitor and assess the impacts of tourism on ecosystem health. However, there is a general lack of information on biological communities in natural reserves of developing countries and of tools for assessing human impacts. In the present study, we investigated macroinvertebrate assemblages in nine lakes in Jiuzhaigou Natural Reserve of China. Both benthic (20 dips of D-net) and light-trap samples (2 h) were collected at each lake and all benthic specimens and adults of Ephemeroptera, Plecoptera, and Trichoptera (EPT) were identified and counted. Water temperature and water quality variables were measured on site or in the Lab. Seventy taxa were recorded and dominated by dipterans and caddisflies. Light traps contributed 47% of taxa richness and 66% of EPT richness at the lakes. Detrended Correspondence Analysis showed that water temperature and tourism index were strongly associated with the changes of assemblage composition. Taxa richness and EPT richness calculated for the composite samples (benthic + light trap) were well fit with Poisson generalized linear model (adjusted R2 = 0.83 and 0.85, respectively), generally decreasing with increasing elevation, tourism index, and total-N. Tourism index was ranked as the top predictor for EPT richness based on multiple model weights, and elevation for taxa richness. In comparison, when based on benthic samples, neither of the metrics could be fitted with the seven environmental variables selected. These findings highlight the benefit of combined use of the sampling methods for lake monitoring and offered an analytical guide to developing biological indicators of lake ecosystem health in protected areas. Close

• 90. [Article] Longitudinal Assessment of Thermal and Perceived Air Quality Acceptability in Relation to Temperature, Humidity, and CO2 Exposure in Singapore

  Thermal acceptability (TA) and perceived air quality acceptability (PAQA) are typically analyzed in climate chambers or cross-sectional field studies. Individual factors, such as expectations and perceived ...

  Citation × Citation Citation Abstract Copy Title: Longitudinal Assessment of Thermal and Perceived Air Quality Acceptability in Relation to Temperature, Humidity, and CO2 Exposure in Singapore Author: Cheung, Toby C.T., Schiavon, Stefano, Gall, Elliot T., Jin, Ming Year: 2017 Thermal acceptability (TA) and perceived air quality acceptability (PAQA) are typically analyzed in climate chambers or cross-sectional field studies. Individual factors, such as expectations and perceived environment history, may influence the acceptability response. Longitudinal studies with multi-day design are absent in the literature. Fifteen Singaporean subjects participated in a 7-day longitudinal experiment in which they carried a portable sensor that continuously recorded personal air temperature, relative humidity and carbon dioxide concentration at 1-min intervals. Instantaneous TA and PAQA were regularly sampled by survey for each subject. High acceptability was found at home, restaurants and workplaces, whereas low acceptability was found for outdoor and transport environments. The participants, from Singapore's modern tropical environment spent an average of 96% of their time indoors. Weak associations were reported between acceptabilities and measured physical parameters taken independently. Clustering data by location, subject's sleeping ventilation habit, air-conditioning operation status and the changes in physical parameters over a designated time period enhanced the understanding of the acceptability results. In general, acceptability was lower for those who slept in air-conditioned environments than for those who slept without air-conditioning. The carbon dioxide mixing ratio was critical for PAQA predictions but not for TA. The Gaussian process (GP) had a better predictive power than a multiple linear regression approach. Using GP, we found that a general predictive model had comparable simulation performance as for individual predictive models. The longitudinal experiment has demonstrated effectiveness for TA and PAQA analysis, which could be beneficial to future studies in personal comfort prediction. Title: Longitudinal Assessment of Thermal and Perceived Air Quality Acceptability in Relation to Temperature, Humidity, and CO2 Exposure in Singapore Author: Cheung, Toby C.T., Schiavon, Stefano, Gall, Elliot T., Jin, Ming Year: 2017 Thermal acceptability (TA) and perceived air quality acceptability (PAQA) are typically analyzed in climate chambers or cross-sectional field studies. Individual factors, such as expectations and perceived environment history, may influence the acceptability response. Longitudinal studies with multi-day design are absent in the literature. Fifteen Singaporean subjects participated in a 7-day longitudinal experiment in which they carried a portable sensor that continuously recorded personal air temperature, relative humidity and carbon dioxide concentration at 1-min intervals. Instantaneous TA and PAQA were regularly sampled by survey for each subject. High acceptability was found at home, restaurants and workplaces, whereas low acceptability was found for outdoor and transport environments. The participants, from Singapore's modern tropical environment spent an average of 96% of their time indoors. Weak associations were reported between acceptabilities and measured physical parameters taken independently. Clustering data by location, subject's sleeping ventilation habit, air-conditioning operation status and the changes in physical parameters over a designated time period enhanced the understanding of the acceptability results. In general, acceptability was lower for those who slept in air-conditioned environments than for those who slept without air-conditioning. The carbon dioxide mixing ratio was critical for PAQA predictions but not for TA. The Gaussian process (GP) had a better predictive power than a multiple linear regression approach. Using GP, we found that a general predictive model had comparable simulation performance as for individual predictive models. The longitudinal experiment has demonstrated effectiveness for TA and PAQA analysis, which could be beneficial to future studies in personal comfort prediction. Close

• 91. [Article] Thermal Footprint Effect of Rooftop Urban Cooling Strategies

  Simulation results indicate that urban morphology plays an important role in determining the efficacy of rooftop urban cooling strategies for improving pedestrian thermal comfort. Results suggest that ...

  Citation × Citation Citation Abstract Copy Title: Thermal Footprint Effect of Rooftop Urban Cooling Strategies Author: Botham-Myint, Dylan, Recktenwald, Gerald W., Sailor, David J. Year: 2015 Simulation results indicate that urban morphology plays an important role in determining the efficacy of rooftop urban cooling strategies for improving pedestrian thermal comfort. Results suggest that a white roof has the greatest effect on near-surface air temperatures within the urban canyon when used on buildings of 1–2 stories height and almost no near-surface effect when applied to 4 story buildings. However, the near-surface effect is more substantial when complex urban morphology introduces enhanced vertical mixing. Of the cases studied the largest near-surface cooling benefit of implementing white roofs was found for the case when a taller building existed downwind from a building with a white roof. Using the Thermal Footprint Ratio it was found that by placing a tall building behind a building with a white roof in an otherwise uniform array of 2 story buildings, the cool roof would be twice as effective at reducing air temperatures at the pedestrian level. Calculations of the volumetric heat removal confirmed this result, indicating that the positioning of the tall building downwind of the modified roof would be 2.6 times as effective at cooling the pedestrian level air volume as compared to the case where all buildings were a uniform height. Title: Thermal Footprint Effect of Rooftop Urban Cooling Strategies Author: Botham-Myint, Dylan, Recktenwald, Gerald W., Sailor, David J. Year: 2015 Simulation results indicate that urban morphology plays an important role in determining the efficacy of rooftop urban cooling strategies for improving pedestrian thermal comfort. Results suggest that a white roof has the greatest effect on near-surface air temperatures within the urban canyon when used on buildings of 1–2 stories height and almost no near-surface effect when applied to 4 story buildings. However, the near-surface effect is more substantial when complex urban morphology introduces enhanced vertical mixing. Of the cases studied the largest near-surface cooling benefit of implementing white roofs was found for the case when a taller building existed downwind from a building with a white roof. Using the Thermal Footprint Ratio it was found that by placing a tall building behind a building with a white roof in an otherwise uniform array of 2 story buildings, the cool roof would be twice as effective at reducing air temperatures at the pedestrian level. Calculations of the volumetric heat removal confirmed this result, indicating that the positioning of the tall building downwind of the modified roof would be 2.6 times as effective at cooling the pedestrian level air volume as compared to the case where all buildings were a uniform height. Close

• 92. [Article] The Differing Biogeochemical and Microbial Signatures of Glaciers and Rock Glaciers

  Glaciers and rock glaciers supply water and bioavailable nutrients to headwater mountain lakes and streams across all regions of the American West. Here we present a comparative study of the metal, nutrient, ...

  Citation × Citation Citation Abstract Copy Title: The Differing Biogeochemical and Microbial Signatures of Glaciers and Rock Glaciers Author: Fegel, Timothy S., Baron, Jill S., Fountain, Andrew G., Johnson, Gunnar F., Hall, Ed K. Year: 2016 Glaciers and rock glaciers supply water and bioavailable nutrients to headwater mountain lakes and streams across all regions of the American West. Here we present a comparative study of the metal, nutrient, and microbial characteristics of glacial and rock glacial influence on headwater ecosystems in three mountain ranges of the contiguous U.S.: the Cascade Mountains, Rocky Mountains, and Sierra Nevada. Several meltwater characteristics (water temperature, conductivity, pH, metals, nutrients, complexity of dissolved organic matter (DOM), and bacterial richness and diversity) differed significantly between glacier and rock glacier meltwaters, while other characteristics (Ca2+, Fe3+, SiO2 concentrations, reactive nitrogen, and microbial processing of DOM) showed distinct trends between mountain ranges regardless of meltwater source. Some characteristics were affected both by glacier type and mountain range (e.g., temperature, ammonium (NH4 +) and nitrate (NO3-) concentrations, and bacterial diversity). Due to the ubiquity of rock glaciers and the accelerating loss of the low-latitude glaciers, our results point to the important and changing influence that these frozen features place on headwater ecosystems. Title: The Differing Biogeochemical and Microbial Signatures of Glaciers and Rock Glaciers Author: Fegel, Timothy S., Baron, Jill S., Fountain, Andrew G., Johnson, Gunnar F., Hall, Ed K. Year: 2016 Glaciers and rock glaciers supply water and bioavailable nutrients to headwater mountain lakes and streams across all regions of the American West. Here we present a comparative study of the metal, nutrient, and microbial characteristics of glacial and rock glacial influence on headwater ecosystems in three mountain ranges of the contiguous U.S.: the Cascade Mountains, Rocky Mountains, and Sierra Nevada. Several meltwater characteristics (water temperature, conductivity, pH, metals, nutrients, complexity of dissolved organic matter (DOM), and bacterial richness and diversity) differed significantly between glacier and rock glacier meltwaters, while other characteristics (Ca2+, Fe3+, SiO2 concentrations, reactive nitrogen, and microbial processing of DOM) showed distinct trends between mountain ranges regardless of meltwater source. Some characteristics were affected both by glacier type and mountain range (e.g., temperature, ammonium (NH4 +) and nitrate (NO3-) concentrations, and bacterial diversity). Due to the ubiquity of rock glaciers and the accelerating loss of the low-latitude glaciers, our results point to the important and changing influence that these frozen features place on headwater ecosystems. Close

• 93. [Article] Gold Tris(carboxyphenyl)corroles as Multifunctional Materials: Room Temperature Near-IR Phosphorescence and Applications to Photodynamic Therapy and Dye-Sensitized Solar Cells

  Two amphiphilic corroles—5,10,15-tris(3-carboxyphenyl)corrole (H3[mTCPC]) and 5,10,15-tris(4-carboxyphenyl)corrole (H3[pTCPC])—and their gold complexes have been synthesized, and their photophysical properties ...

  Citation × Citation Citation Abstract Copy Title: Gold Tris(carboxyphenyl)corroles as Multifunctional Materials: Room Temperature Near-IR Phosphorescence and Applications to Photodynamic Therapy and Dye-Sensitized Solar Cells Author: Alemayehu, Abraham B., Day, Nicholas U., Mani, Tomoyasu, Rudine, Alexander B., Thomas, Kolle E., Gederaas, Odrun A., Vinogradov, Sergei A., Wamser, Carl C., Ghosh, Abhik Year: 2016 Two amphiphilic corroles—5,10,15-tris(3-carboxyphenyl)corrole (H3[mTCPC]) and 5,10,15-tris(4-carboxyphenyl)corrole (H3[pTCPC])—and their gold complexes have been synthesized, and their photophysical properties and photovoltaic behavior have been investigated. Like other nonpolar gold corroles, Au[mTCPC] and Au[pTCPC] were both found to exhibit room temperature phosphorescence in deoxygenated solutions with quantum yields of ∼0.3% and triplet lifetimes of ∼75 μs. Both compounds exhibited significant activity as dyes in photodynamic therapy experiments and in dye-sensitized solar cells. Upon irradiation at 435 nm, both Au corroles exhibited significant phototoxicity against AY27 rat bladder cancer cells while the free-base corroles proved inactive. Dye-sensitized solar cells constructed using the free bases H3[mTCPC] and H3[pTCPC] exhibited low efficiencies (≪1%), well under that obtained with 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin, H2[pTCPP] (1.9%, cf. N719 9.5%). Likewise, Au[pTCPC] proved inefficient, with an efficiency of ∼0.2%. By contrast, Au[mTCPC] proved remarkably effective, exhibiting an open-circuit voltage (Voc) of 0.56 V, a short-circuit current of 8.7 mA cm–2, a fill factor of 0.72, and an efficiency of 3.5%. Title: Gold Tris(carboxyphenyl)corroles as Multifunctional Materials: Room Temperature Near-IR Phosphorescence and Applications to Photodynamic Therapy and Dye-Sensitized Solar Cells Author: Alemayehu, Abraham B., Day, Nicholas U., Mani, Tomoyasu, Rudine, Alexander B., Thomas, Kolle E., Gederaas, Odrun A., Vinogradov, Sergei A., Wamser, Carl C., Ghosh, Abhik Year: 2016 Two amphiphilic corroles—5,10,15-tris(3-carboxyphenyl)corrole (H3[mTCPC]) and 5,10,15-tris(4-carboxyphenyl)corrole (H3[pTCPC])—and their gold complexes have been synthesized, and their photophysical properties and photovoltaic behavior have been investigated. Like other nonpolar gold corroles, Au[mTCPC] and Au[pTCPC] were both found to exhibit room temperature phosphorescence in deoxygenated solutions with quantum yields of ∼0.3% and triplet lifetimes of ∼75 μs. Both compounds exhibited significant activity as dyes in photodynamic therapy experiments and in dye-sensitized solar cells. Upon irradiation at 435 nm, both Au corroles exhibited significant phototoxicity against AY27 rat bladder cancer cells while the free-base corroles proved inactive. Dye-sensitized solar cells constructed using the free bases H3[mTCPC] and H3[pTCPC] exhibited low efficiencies (≪1%), well under that obtained with 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin, H2[pTCPP] (1.9%, cf. N719 9.5%). Likewise, Au[pTCPC] proved inefficient, with an efficiency of ∼0.2%. By contrast, Au[mTCPC] proved remarkably effective, exhibiting an open-circuit voltage (Voc) of 0.56 V, a short-circuit current of 8.7 mA cm–2, a fill factor of 0.72, and an efficiency of 3.5%. Close

• 94. [Article] Epigenetic Regulation of Alternative Developmental Trajectories

  The annual killifish, Austrofundulus limnaeus, is capable of entering into a state of metabolic and developmental dormancy during embryogenesis termed diapause. However, individuals may also follow an ...

  Citation × Citation Citation Abstract Copy Title: Epigenetic Regulation of Alternative Developmental Trajectories Author: Romney, Arnie Lynn T., Podrabsky, Jason E. Year: 2017 The annual killifish, Austrofundulus limnaeus, is capable of entering into a state of metabolic and developmental dormancy during embryogenesis termed diapause. However, individuals may also follow an alternative phenotypic trajectory and instead "escaped" entry into diapause and develop continuously until hatching. Early development along the two trajectories is morphologically indistinguishable, and gene regulatory mechanisms are currently unknown. Phenotype appears to be influenced by maternal provisioning based on the observation that young females produce predominately escape embryos and older females produce diapausing embryos. Additionally, the incubation temperature of embryos can override this maternal pattern and alter trajectory. Maternal provisioning is known in many vertebrates to direct early development prior to the initiation of embryonic gene transcription. Using RNA-seq, we have generated transcriptomic profiles of messenger RNAs (mRNAs) during embryogenesis of A. limnaeus. Embryos that are destined for either the diapause or escape phenotypes have unique profiles of mRNA isoforms at fertilization; well before they are morphologically distinct. We hypothesize that maternally packaged gene products coordinate the cellular events that determine developmental trajectory in A. limnaeus. In addition, we propose the expression of environmentally responsive microRNAs during development that can override maternal provisioning. RNA-seq data during early development, after the maternal-to-zygotic transition, suggest distinct profiles of microRNA expression that are phenotype specific. Our findings suggest maternal programming of diapause through the packaging of specific mRNAs as well as temperature induced microRNAs that target maternal transcripts allowing an escape from the diapause trajectory. This presents a novel example of maternal-embryonic-conflict in gene regulation that provides the embryo with alternatives in developmental trajectories in the face of fluctuating environmental patterns. These results will not only impact our understanding of genetic mechanisms that regulate entrance into diapause, but will also provide insight into epigenetic control of development. Title: Epigenetic Regulation of Alternative Developmental Trajectories Author: Romney, Arnie Lynn T., Podrabsky, Jason E. Year: 2017 The annual killifish, Austrofundulus limnaeus, is capable of entering into a state of metabolic and developmental dormancy during embryogenesis termed diapause. However, individuals may also follow an alternative phenotypic trajectory and instead "escaped" entry into diapause and develop continuously until hatching. Early development along the two trajectories is morphologically indistinguishable, and gene regulatory mechanisms are currently unknown. Phenotype appears to be influenced by maternal provisioning based on the observation that young females produce predominately escape embryos and older females produce diapausing embryos. Additionally, the incubation temperature of embryos can override this maternal pattern and alter trajectory. Maternal provisioning is known in many vertebrates to direct early development prior to the initiation of embryonic gene transcription. Using RNA-seq, we have generated transcriptomic profiles of messenger RNAs (mRNAs) during embryogenesis of A. limnaeus. Embryos that are destined for either the diapause or escape phenotypes have unique profiles of mRNA isoforms at fertilization; well before they are morphologically distinct. We hypothesize that maternally packaged gene products coordinate the cellular events that determine developmental trajectory in A. limnaeus. In addition, we propose the expression of environmentally responsive microRNAs during development that can override maternal provisioning. RNA-seq data during early development, after the maternal-to-zygotic transition, suggest distinct profiles of microRNA expression that are phenotype specific. Our findings suggest maternal programming of diapause through the packaging of specific mRNAs as well as temperature induced microRNAs that target maternal transcripts allowing an escape from the diapause trajectory. This presents a novel example of maternal-embryonic-conflict in gene regulation that provides the embryo with alternatives in developmental trajectories in the face of fluctuating environmental patterns. These results will not only impact our understanding of genetic mechanisms that regulate entrance into diapause, but will also provide insight into epigenetic control of development. Close

• 95. [Article] Portland State University School of Business Administration (SBA) Renovation + Personal Comfort Investigation

  This poster discusses the results of a field study about indoor thermal comfort, based on investigations in Portland State University`s School of Business (SBA) classrooms. The field study was conducted ...

  Citation × Citation Citation Abstract Copy Title: Portland State University School of Business Administration (SBA) Renovation + Personal Comfort Investigation Author: Mekanik, Abolfazl, Griffin, Corey, Foster, Louise Year: 2015 This poster discusses the results of a field study about indoor thermal comfort, based on investigations in Portland State University`s School of Business (SBA) classrooms. The field study was conducted by physical parameter monitoring and questionnaires. Both field monitoring and occupant surveys were performed at the same time during the regular class period.The measurement campaign consisted of measuring the environmental parameters such as temperature (Ta), relative humidity (RH), CO2, and sound levels. The outdoor air temperature, humidity, and sound were registered every 2 hour period during class time. The intention for this project is to investigate thermal comfort of occupants by survey and compare that with the monitored indoor thermal comfort of the occupants. This could assist designers in measuring the energy needed to provide adequate thermal comfort. The results show that classrooms are nearly in a comfort zone and based on the location of the classrooms in the SBA the comfort level is different and students responds differently. The first significant goal in this project is to use these data to decrease the amount of energy that is used in this building by applying new methods in the renovation of these classrooms. The design group intends to execute passive strategies to reach this goal. The second goal is to enhance the educational environment, in terms of thermal conditions, to help students to be more focused on the subjects in the classrooms. Title: Portland State University School of Business Administration (SBA) Renovation + Personal Comfort Investigation Author: Mekanik, Abolfazl, Griffin, Corey, Foster, Louise Year: 2015 This poster discusses the results of a field study about indoor thermal comfort, based on investigations in Portland State University`s School of Business (SBA) classrooms. The field study was conducted by physical parameter monitoring and questionnaires. Both field monitoring and occupant surveys were performed at the same time during the regular class period.The measurement campaign consisted of measuring the environmental parameters such as temperature (Ta), relative humidity (RH), CO2, and sound levels. The outdoor air temperature, humidity, and sound were registered every 2 hour period during class time. The intention for this project is to investigate thermal comfort of occupants by survey and compare that with the monitored indoor thermal comfort of the occupants. This could assist designers in measuring the energy needed to provide adequate thermal comfort. The results show that classrooms are nearly in a comfort zone and based on the location of the classrooms in the SBA the comfort level is different and students responds differently. The first significant goal in this project is to use these data to decrease the amount of energy that is used in this building by applying new methods in the renovation of these classrooms. The design group intends to execute passive strategies to reach this goal. The second goal is to enhance the educational environment, in terms of thermal conditions, to help students to be more focused on the subjects in the classrooms. Close

• 96. [Article] OSMB Final Report, Task 4: Oregon Lake Watch

  The Oregon Lake Watch (OLW) volunteer monitoring program was resurrected after over a decade in hibernation. The new program was designed to educate the public about threats of aquatic invasive species ...

  Citation × Citation Citation Abstract Copy Title: OSMB Final Report, Task 4: Oregon Lake Watch Author: Strecker, Angela L., Miller, Rich, Morgan, Vanessa Year: 2014 The Oregon Lake Watch (OLW) volunteer monitoring program was resurrected after over a decade in hibernation. The new program was designed to educate the public about threats of aquatic invasive species (AIS), provide early detection of AIS invasions, and provide long term water quality data for the better management of Oregon’s lakes and reservoirs. Protocols were created for citizen scientists to survey for AIS, collect temperature and water clarity data, and record the data through an online data entry portal. An OLW website was developed to educate about AIS and provide survey protocols and identification materials to volunteers. AIS surveys were focused on Watch List Species which are selected AIS that have a negative impact on the beneficial uses of our waterbodies. Eighteen volunteers were trained during five sessions conducted in western and central Oregon. Fourteen of the trained volunteers collected data from sixteen waterbodies. Six Watch List species and one other AIS species were observed in four of the waterbodies. The three Watch List Species observed in Salish Pond and one in Olallie Lake were new observations. Temperature measurements indicated a wide range of thermal profiles and Secchi transparency measurement indicated a range of trophic status from oligotrophic to eutrophic. Title: OSMB Final Report, Task 4: Oregon Lake Watch Author: Strecker, Angela L., Miller, Rich, Morgan, Vanessa Year: 2014 The Oregon Lake Watch (OLW) volunteer monitoring program was resurrected after over a decade in hibernation. The new program was designed to educate the public about threats of aquatic invasive species (AIS), provide early detection of AIS invasions, and provide long term water quality data for the better management of Oregon’s lakes and reservoirs. Protocols were created for citizen scientists to survey for AIS, collect temperature and water clarity data, and record the data through an online data entry portal. An OLW website was developed to educate about AIS and provide survey protocols and identification materials to volunteers. AIS surveys were focused on Watch List Species which are selected AIS that have a negative impact on the beneficial uses of our waterbodies. Eighteen volunteers were trained during five sessions conducted in western and central Oregon. Fourteen of the trained volunteers collected data from sixteen waterbodies. Six Watch List species and one other AIS species were observed in four of the waterbodies. The three Watch List Species observed in Salish Pond and one in Olallie Lake were new observations. Temperature measurements indicated a wide range of thermal profiles and Secchi transparency measurement indicated a range of trophic status from oligotrophic to eutrophic. Close

• 97. [Article] Developing High-Resolution Descriptions of Urban Heat Islands: A Public Health Imperative

  Extreme heat events affect the most vulnerable human populations and are a lethal health hazard to urban dwellers globally; in the United States, extreme heat causes more deaths annually than all other ...

  Citation × Citation Citation Abstract Copy Title: Developing High-Resolution Descriptions of Urban Heat Islands: A Public Health Imperative Author: Voelkel, Jackson, Shandas, Vivek, Haggerty, Brendon Year: 2016 Extreme heat events affect the most vulnerable human populations and are a lethal health hazard to urban dwellers globally; in the United States, extreme heat causes more deaths annually than all other weather events and natural hazards combined (1). Previous studies described urban heat islands as isolated, static, monolithic areas of cities. We challenged this contention by hypothesizing that diurnal temperature cycles and diverse landscape features create variation in places that amplify heat (2). A temporal description of urban heat islands would identify populations that are susceptible to heat stress, particularly at night, when most people are asleep and unable to regulate internal body temperatures. If public health agencies are to prevent illness and death caused by heat, they will need to know which populations are most vulnerable to heat stress, particularly at night; such information can guide timely interventions (3). Researchers lack high-resolution tools for identifying neighborhoods and households where extreme weather events might have profound and fatal effects on human health. The objective of this study was to use spatial analytics at previously unattained resolutions to answer the following research question: to what extent can we observe temporal variation in urban heat islands and the physical features that induce heat stress? Title: Developing High-Resolution Descriptions of Urban Heat Islands: A Public Health Imperative Author: Voelkel, Jackson, Shandas, Vivek, Haggerty, Brendon Year: 2016 Extreme heat events affect the most vulnerable human populations and are a lethal health hazard to urban dwellers globally; in the United States, extreme heat causes more deaths annually than all other weather events and natural hazards combined (1). Previous studies described urban heat islands as isolated, static, monolithic areas of cities. We challenged this contention by hypothesizing that diurnal temperature cycles and diverse landscape features create variation in places that amplify heat (2). A temporal description of urban heat islands would identify populations that are susceptible to heat stress, particularly at night, when most people are asleep and unable to regulate internal body temperatures. If public health agencies are to prevent illness and death caused by heat, they will need to know which populations are most vulnerable to heat stress, particularly at night; such information can guide timely interventions (3). Researchers lack high-resolution tools for identifying neighborhoods and households where extreme weather events might have profound and fatal effects on human health. The objective of this study was to use spatial analytics at previously unattained resolutions to answer the following research question: to what extent can we observe temporal variation in urban heat islands and the physical features that induce heat stress? Close

• 98. [Article] Dynamic Effect of Light and Turbulence on Algal Photosynthetic Rate: A Water-Quality Model

  Several studies provide evidence that algal photosynthetic rates depend on various changing factors such as light attenuation, temperature, and nutrient limitation (Chapra, 1997). However, recent papers ...

  Citation × Citation Citation Abstract Copy Title: Dynamic Effect of Light and Turbulence on Algal Photosynthetic Rate: A Water-Quality Model Author: Rivas, Andres R. Year: 2015 Several studies provide evidence that algal photosynthetic rates depend on various changing factors such as light attenuation, temperature, and nutrient limitation (Chapra, 1997). However, recent papers show that turbulence and photosynthetic rate dynamics is also important (Ross, 2006). In this study, the photosynthetic rate model used is the one proposed by Chapra (1997), where it depends directly on temperature, nutrient and light limitation factors. At the same time, the effect of turbulence or random-walk of algae particles in the water column was also introduced in this model. To account for this factor, the model added was that proposed by Ross (2006), in which the random movement of an algae particle depends on an initial position, a sinking or swimming velocity, an advective term and a random term related to probability. An example test is proposed to evaluate the model and all the parameters and variables are pre-established to show a natural example commonly found in nature. The values of photosynthetic rate were obtained on average and point by point, the photosynthetic rate evolution with time was evaluated. Simulations results are consistent with literature, specifically the photosynthetic rate dynamic behavior, and wereas compared with the results obtained by Harris (1977), Marra (1978), and Ross (2006). Some aspects of the dynamic effect of light attenuation and turbulence on photosynthetic rate are investigated through the model Title: Dynamic Effect of Light and Turbulence on Algal Photosynthetic Rate: A Water-Quality Model Author: Rivas, Andres R. Year: 2015 Several studies provide evidence that algal photosynthetic rates depend on various changing factors such as light attenuation, temperature, and nutrient limitation (Chapra, 1997). However, recent papers show that turbulence and photosynthetic rate dynamics is also important (Ross, 2006). In this study, the photosynthetic rate model used is the one proposed by Chapra (1997), where it depends directly on temperature, nutrient and light limitation factors. At the same time, the effect of turbulence or random-walk of algae particles in the water column was also introduced in this model. To account for this factor, the model added was that proposed by Ross (2006), in which the random movement of an algae particle depends on an initial position, a sinking or swimming velocity, an advective term and a random term related to probability. An example test is proposed to evaluate the model and all the parameters and variables are pre-established to show a natural example commonly found in nature. The values of photosynthetic rate were obtained on average and point by point, the photosynthetic rate evolution with time was evaluated. Simulations results are consistent with literature, specifically the photosynthetic rate dynamic behavior, and wereas compared with the results obtained by Harris (1977), Marra (1978), and Ross (2006). Some aspects of the dynamic effect of light attenuation and turbulence on photosynthetic rate are investigated through the model Close

• 99. [Article] Application of CE-QUAL-W2 on Tigris River in Iraq

  The Tigris River is the eastern member of the two great rivers in Iraq. Two big rivers pass through Iraq, Mesopotamia. Tigris and Euphrates Rivers with their tributaries form a major river system in the ...

  Citation × Citation Citation Abstract Copy Title: Application of CE-QUAL-W2 on Tigris River in Iraq Author: Al-Murib, Muhanned Year: 2014 The Tigris River is the eastern member of the two great rivers in Iraq. Two big rivers pass through Iraq, Mesopotamia. Tigris and Euphrates Rivers with their tributaries form a major river system in the Middle East. Four riparian countries, Turkey, Syria, Iran, and Iraq, share the Tigris River basin area and Iraq has the majority of this basin area. The total length of the Tigris is 1850 km from which 1418 km is within Iraq. A study area of 880 km from Mosul dam to Kut barrage is modeled using a water quality CE-QUAL-W2 model. CE-QUAL-W2 is a two-dimensional (longitudinal and vertical) water quality model developed by the U.S. Army Corps of Engineers and Portland State University. W2 simulates river circulation, stage, vertical and horizontal velocities, water temperature, and a host of water quality constituents. Total dissolved solids (TDS) is the main concern in Iraq because Iraq heavily depends on its water for irrigation purposes. Therefore, this project discusses the implementation of CE-QUAL-W2 model on Tigris River to simulate flow, temperature, and TDS. Title: Application of CE-QUAL-W2 on Tigris River in Iraq Author: Al-Murib, Muhanned Year: 2014 The Tigris River is the eastern member of the two great rivers in Iraq. Two big rivers pass through Iraq, Mesopotamia. Tigris and Euphrates Rivers with their tributaries form a major river system in the Middle East. Four riparian countries, Turkey, Syria, Iran, and Iraq, share the Tigris River basin area and Iraq has the majority of this basin area. The total length of the Tigris is 1850 km from which 1418 km is within Iraq. A study area of 880 km from Mosul dam to Kut barrage is modeled using a water quality CE-QUAL-W2 model. CE-QUAL-W2 is a two-dimensional (longitudinal and vertical) water quality model developed by the U.S. Army Corps of Engineers and Portland State University. W2 simulates river circulation, stage, vertical and horizontal velocities, water temperature, and a host of water quality constituents. Total dissolved solids (TDS) is the main concern in Iraq because Iraq heavily depends on its water for irrigation purposes. Therefore, this project discusses the implementation of CE-QUAL-W2 model on Tigris River to simulate flow, temperature, and TDS. Close

• 100. [Article] Assessing Mechanisms of Climate Change Impact on the Upland Forest Water Balance of the Willamette River Basin, Oregon

  Projected changes in air temperature, precipitation, and vapor pressure for the Willamette River Basin (Oregon, USA) over the next century will have significant impacts on the river basin water balance, ...

  Citation × Citation Citation Abstract Copy Title: Assessing Mechanisms of Climate Change Impact on the Upland Forest Water Balance of the Willamette River Basin, Oregon Author: Turner, David P., Conklin, David R., Vache, Kellie B., Schwartz, Cynthia, Nolin, Anne, Chang, Heejun, Watson, Eric, Bolte, John P. Year: 2016 Projected changes in air temperature, precipitation, and vapor pressure for the Willamette River Basin (Oregon, USA) over the next century will have significant impacts on the river basin water balance, notably on the amount of evapotranspiration (ET). Mechanisms of impact on ET will be both direct and indirect, but there is limited understanding of their absolute and relative magnitudes. Here, we developed a spatially explicit, daily time-step, modeling infrastructure to simulate the basin-wide water balance that accounts for meteorological influences, as well as effects mediated by changing vegetation cover type, leaf area, and ecophysiology. Three CMIP5 climate scenarios (Lowclim, Reference, and HighClim) were run for the 2010–2100 period. Besides warmer temperatures, the climate scenarios were characterized by wetter winters and increasing vapor pressure deficits. In the mid-range Reference scenario, our landscape simulation model (Envision) projected a continuation of forest cover on the uplands but a threefold increase in area burned per year. A decline (12–30%) in basin-wide mean leaf area index (LAI) in forests was projected in all scenarios. The lower LAIs drove a corresponding decline in ET. In a sensitivity test, the effect of increasing CO2 on stomatal conductance induced a further substantial decrease (11–18%) in basin-wide mean ET. The net effect of decreases in ET and increases in winter precipitation was an increase in annual streamflow. These results support the inclusion of changes in land cover, land use, LAI, and ecophysiology in efforts to anticipate impacts of climate change on basin-scale water balances. Title: Assessing Mechanisms of Climate Change Impact on the Upland Forest Water Balance of the Willamette River Basin, Oregon Author: Turner, David P., Conklin, David R., Vache, Kellie B., Schwartz, Cynthia, Nolin, Anne, Chang, Heejun, Watson, Eric, Bolte, John P. Year: 2016 Projected changes in air temperature, precipitation, and vapor pressure for the Willamette River Basin (Oregon, USA) over the next century will have significant impacts on the river basin water balance, notably on the amount of evapotranspiration (ET). Mechanisms of impact on ET will be both direct and indirect, but there is limited understanding of their absolute and relative magnitudes. Here, we developed a spatially explicit, daily time-step, modeling infrastructure to simulate the basin-wide water balance that accounts for meteorological influences, as well as effects mediated by changing vegetation cover type, leaf area, and ecophysiology. Three CMIP5 climate scenarios (Lowclim, Reference, and HighClim) were run for the 2010–2100 period. Besides warmer temperatures, the climate scenarios were characterized by wetter winters and increasing vapor pressure deficits. In the mid-range Reference scenario, our landscape simulation model (Envision) projected a continuation of forest cover on the uplands but a threefold increase in area burned per year. A decline (12–30%) in basin-wide mean leaf area index (LAI) in forests was projected in all scenarios. The lower LAIs drove a corresponding decline in ET. In a sensitivity test, the effect of increasing CO2 on stomatal conductance induced a further substantial decrease (11–18%) in basin-wide mean ET. The net effect of decreases in ET and increases in winter precipitation was an increase in annual streamflow. These results support the inclusion of changes in land cover, land use, LAI, and ecophysiology in efforts to anticipate impacts of climate change on basin-scale water balances. Close