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• 1. [Article] The effect of cold acclimation on the temperature preference of the goldfish, Carassius auratus, and the brown bullhead, Ictalurus nebulosus

  Two species of fish, Carassius auratus and Ictalurus nebulosus, were subjected to cold acclimation regimes. Acclimation temperatures were slowly lowered to 3°c, then held for a period of time. At various ...

  Citation × Citation Citation Abstract Copy Title: The effect of cold acclimation on the temperature preference of the goldfish, Carassius auratus, and the brown bullhead, Ictalurus nebulosus Author: Lord, Alfred Year: 1987 Two species of fish, Carassius auratus and Ictalurus nebulosus, were subjected to cold acclimation regimes. Acclimation temperatures were slowly lowered to 3°c, then held for a period of time. At various times during this regime, fish were taken out and allowed to spend time in a temperature gradient to determine their preferred temperatures. Carassius were left in the gradient just long enough to determine a measure of the acute temperature preference, while Ictalurus were left in the temperature gradient for longer periods of time to observe any changes that might occur as the fish adjusted to selected temperatures. In both species of fish, lower acclimation temperatures and increased time spent at low temperatures caused a preference for lower temperatures in the gradient. Title: The effect of cold acclimation on the temperature preference of the goldfish, Carassius auratus, and the brown bullhead, Ictalurus nebulosus Author: Lord, Alfred Year: 1987 Two species of fish, Carassius auratus and Ictalurus nebulosus, were subjected to cold acclimation regimes. Acclimation temperatures were slowly lowered to 3°c, then held for a period of time. At various times during this regime, fish were taken out and allowed to spend time in a temperature gradient to determine their preferred temperatures. Carassius were left in the gradient just long enough to determine a measure of the acute temperature preference, while Ictalurus were left in the temperature gradient for longer periods of time to observe any changes that might occur as the fish adjusted to selected temperatures. In both species of fish, lower acclimation temperatures and increased time spent at low temperatures caused a preference for lower temperatures in the gradient. Close

• 2. [Article] Internal Temperature of Douglas-Fir Buds is Altered at Elevated Temperature

  Pseudotsuga menziesii (Douglas-fir) saplings were grown in sun-lit controlled environment chambers at ambient or elevated (4°C above ambient) temperature. We measured internal temperatures of vegetative ...

  Citation × Citation Citation Abstract Copy Title: Internal Temperature of Douglas-Fir Buds is Altered at Elevated Temperature Author: Apple, Martha E., Lucash, Melissa S., Olszyk, David M., Tingey, David T., Phillips, Donald L. Year: 1999 Pseudotsuga menziesii (Douglas-fir) saplings were grown in sun-lit controlled environment chambers at ambient or elevated (4°C above ambient) temperature. We measured internal temperatures of vegetative buds with thermocouple probes and compared temperatures of normal buds and abnormal buds with loosened, rosetted outer scales in elevated temperature chambers. The abnormal buds had higher and earlier peak daily temperatures than normal buds. Elevated temperature may influence the internal temperature of buds and contribute to the development of abnormal, rosetted buds with loosened outer scales. Abnormal bud development may alter branching patterns and allometry of Douglas-fir trees subjected to climatic change. Title: Internal Temperature of Douglas-Fir Buds is Altered at Elevated Temperature Author: Apple, Martha E., Lucash, Melissa S., Olszyk, David M., Tingey, David T., Phillips, Donald L. Year: 1999 Pseudotsuga menziesii (Douglas-fir) saplings were grown in sun-lit controlled environment chambers at ambient or elevated (4°C above ambient) temperature. We measured internal temperatures of vegetative buds with thermocouple probes and compared temperatures of normal buds and abnormal buds with loosened, rosetted outer scales in elevated temperature chambers. The abnormal buds had higher and earlier peak daily temperatures than normal buds. Elevated temperature may influence the internal temperature of buds and contribute to the development of abnormal, rosetted buds with loosened outer scales. Abnormal bud development may alter branching patterns and allometry of Douglas-fir trees subjected to climatic change. Close

• 3. [Article] High Mobility Group Protein 1 (HMGB1) And Its Role As A Global Transcription Regulator In Response To Temperature Fluctuations In The Annual Killifish Austrofundulus limnaeus

  As a study organism, annual killifish (Austrofundulus limnaeus) provide a well suited study system for examining the effects of environmental temperature fluctuations at the cellular level. A. limnaeus ...

  Citation × Citation Citation Abstract Copy Title: High Mobility Group Protein 1 (HMGB1) And Its Role As A Global Transcription Regulator In Response To Temperature Fluctuations In The Annual Killifish Austrofundulus limnaeus Author: Alla, Victoria Martin Year: 2011 As a study organism, annual killifish (Austrofundulus limnaeus) provide a well suited study system for examining the effects of environmental temperature fluctuations at the cellular level. A. limnaeus persist in the harsh high desert climate of the Maracaibo Basin, Venezuela where they live in small, ephemeral freshwater pools. Temperatures in these waters can vary as much as 20 degrees C daily and reach maximums of over 40 degrees C due to the semi-arid climate. Previous cDNA microarray studies on killifish revealed the mRNA pattern for High Mobility Group Protein 1 (HMGB1) to be strongly affected by temperature perturbations. Specifically, peaks in hmgb1 transcript abundance were negatively correlated with temperature during temperature cycling, and experienced over a 10 fold difference in expression in response to the temperature cycle. Using the same temperature cycling experimental setup, this study's aim was three-fold: (1) to characterize the total amount of HMGB1 protein in adult male killifish livers, (2) to describe the subcellular localization of the HMGB1 protein in adult male killifish livers and (3) to sequence the 5' upstream region of the hmgb1 gene to identify possible stress responsive elements. We detected no significant difference in total HMGB1 protein levels as a consequence of temperature cycling. The data for subcellular localization of HGMB1 protein do not support a strong change in subcellular localization of the protein in response to temperature cycling; most of the HMGB1 protein is found in the cytoplasmic compartment in liver tissue. Although overall patterns of subcellular localization did not change significantly, we found a significant difference between nuclear HMGB1 protein levels in temperature cycled fish versus control (constant temperature) fish. This could suggest a muting of the natural translocation of HMGB1 into the nucleus observed in control fish at around 9:00 at night. Finally, the upstream region of the hgmb1 gene does reveal a number of putative stress responsive transcription factor binding sites. Title: High Mobility Group Protein 1 (HMGB1) And Its Role As A Global Transcription Regulator In Response To Temperature Fluctuations In The Annual Killifish Austrofundulus limnaeus Author: Alla, Victoria Martin Year: 2011 As a study organism, annual killifish (Austrofundulus limnaeus) provide a well suited study system for examining the effects of environmental temperature fluctuations at the cellular level. A. limnaeus persist in the harsh high desert climate of the Maracaibo Basin, Venezuela where they live in small, ephemeral freshwater pools. Temperatures in these waters can vary as much as 20 degrees C daily and reach maximums of over 40 degrees C due to the semi-arid climate. Previous cDNA microarray studies on killifish revealed the mRNA pattern for High Mobility Group Protein 1 (HMGB1) to be strongly affected by temperature perturbations. Specifically, peaks in hmgb1 transcript abundance were negatively correlated with temperature during temperature cycling, and experienced over a 10 fold difference in expression in response to the temperature cycle. Using the same temperature cycling experimental setup, this study's aim was three-fold: (1) to characterize the total amount of HMGB1 protein in adult male killifish livers, (2) to describe the subcellular localization of the HMGB1 protein in adult male killifish livers and (3) to sequence the 5' upstream region of the hmgb1 gene to identify possible stress responsive elements. We detected no significant difference in total HMGB1 protein levels as a consequence of temperature cycling. The data for subcellular localization of HGMB1 protein do not support a strong change in subcellular localization of the protein in response to temperature cycling; most of the HMGB1 protein is found in the cytoplasmic compartment in liver tissue. Although overall patterns of subcellular localization did not change significantly, we found a significant difference between nuclear HMGB1 protein levels in temperature cycled fish versus control (constant temperature) fish. This could suggest a muting of the natural translocation of HMGB1 into the nucleus observed in control fish at around 9:00 at night. Finally, the upstream region of the hgmb1 gene does reveal a number of putative stress responsive transcription factor binding sites. Close

• 4. [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

• 5. [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

• 6. [Article] Spatial and temporal characteristics of surface air temperature for Portland, Oregon

  This study examines the spatial and temporal characteristics of the surface air temperature in Portland, Oregon. Spatial temperature patterns indicate that the dominant control factors on seasonal temperature ...

  Citation × Citation Citation Abstract Copy Title: Spatial and temporal characteristics of surface air temperature for Portland, Oregon Author: Yang, Li-min Year: 1987 This study examines the spatial and temporal characteristics of the surface air temperature in Portland, Oregon. Spatial temperature patterns indicate that the dominant control factors on seasonal temperature distribution are local topography, elevation, and urban-rural differences in surface structure. A heat island exists in the Portland area; the intensity of the heat island rang€s from 4° to 10° F, and varies throughout the year. The strongest heat island is found in the July minimum temperature. Temperature distribution in Portland and the adjacent area is affected by winds and rainy conditions, but less influenced under overcast skies. The long-term temperature over the last century shows that Portland's mean annual temperature trends are 0.057° F/yr and 0.052° F/yr in the two warming periods 1900-1940 and 1961-1984, respectively, and these warming trends are largely due to warming in spring and early summer as well as in winter months except January. Comparisons between Portland and other local non-urban climatic stations show a general warming trend in Portland since the end of the last century, which is 0.028° F/yr in the mean annual temperature, and 0.017° F/yr in maximum temperature after the regional trends are removed. Monthly mean temperature in July and January demonstrate a warming by 0.023° F/yr and 0.015° F/yr at Portland, respectively. All these warming trends are due mainly to the impact of urbanization. It is found that the cooling effect on the northern Willamette Valley due to the presence of the Columbia Gorge is most noticeable in the daytime and in January. Title: Spatial and temporal characteristics of surface air temperature for Portland, Oregon Author: Yang, Li-min Year: 1987 This study examines the spatial and temporal characteristics of the surface air temperature in Portland, Oregon. Spatial temperature patterns indicate that the dominant control factors on seasonal temperature distribution are local topography, elevation, and urban-rural differences in surface structure. A heat island exists in the Portland area; the intensity of the heat island rang€s from 4° to 10° F, and varies throughout the year. The strongest heat island is found in the July minimum temperature. Temperature distribution in Portland and the adjacent area is affected by winds and rainy conditions, but less influenced under overcast skies. The long-term temperature over the last century shows that Portland's mean annual temperature trends are 0.057° F/yr and 0.052° F/yr in the two warming periods 1900-1940 and 1961-1984, respectively, and these warming trends are largely due to warming in spring and early summer as well as in winter months except January. Comparisons between Portland and other local non-urban climatic stations show a general warming trend in Portland since the end of the last century, which is 0.028° F/yr in the mean annual temperature, and 0.017° F/yr in maximum temperature after the regional trends are removed. Monthly mean temperature in July and January demonstrate a warming by 0.023° F/yr and 0.015° F/yr at Portland, respectively. All these warming trends are due mainly to the impact of urbanization. It is found that the cooling effect on the northern Willamette Valley due to the presence of the Columbia Gorge is most noticeable in the daytime and in January. Close

• 7. [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

• 8. [Article] Optimization of single- and double-flash cycles and space heating systems in geothermal engineering

  Two different problems of optimization in the utilization of geothermal energy are presented: First, the thermodynamic optimization for a geothermal power plant using a single- or double-flash process ...

  Citation × Citation Citation Abstract Copy Title: Optimization of single- and double-flash cycles and space heating systems in geothermal engineering Author: Hassoun, Talal Hussein Year: 1974 Two different problems of optimization in the utilization of geothermal energy are presented: First, the thermodynamic optimization for a geothermal power plant using a single- or double-flash process is considered; in this analysis, the optimum flash temperature giving the maximum power output is determined. Second, an economic optimization for space heating systems using geothermal energy is developed to obtain operating conditions for which the total (capital and operating) cost is a minimum. Both graphical and analytical methods are used in the thermodynamic optimization to determine the optimum flash temperature. The graphical method is based on thermodynamic data provided by an i-s (enthalpy-entropy) diagram for water and steam, in the analytical method, first and second order approximations (first and second degree polynomial approximations), are used for the functions which express enthalpy differences in terms of flash temperature. Numerical results are provided by computer programs developed for the analytical method. These results cover the temperature range normally encountered in practice. In the case of the single-flash cycle, results from both the graphical and analytical method using the first order approximation indicate the same optimum flash temperature; however, the correction factor resulting from the second order approximation improves the value of the temperature by a correction of about -2 ° C. Optimum flash temperatures for the double-flash cycle are similarly determined using the analytical method with a first order approximation. In the economic optimization of space heating systems, the analysis is made on the basis of the annual total cost per unit area of wall surface. It takes into account the cost of the geothermal fluid, cost of wall insulation, and heat exchanger cost. For a specific case where the inlet temperature to the heat exchanger is at 100° C and the outlet temperature at 28° C, the minimum annual cost to maintain a space at 20°C with an outside temperature of -l0°C is given at $0.0257 per square meter of wall area while the optimum thickness for the wall insulation is 0. 126 meter. Additional improvement in the optimization of flash temperature can be made by using a second order approximation method for the double-flash power cycle. Title: Optimization of single- and double-flash cycles and space heating systems in geothermal engineering Author: Hassoun, Talal Hussein Year: 1974 Two different problems of optimization in the utilization of geothermal energy are presented: First, the thermodynamic optimization for a geothermal power plant using a single- or double-flash process is considered; in this analysis, the optimum flash temperature giving the maximum power output is determined. Second, an economic optimization for space heating systems using geothermal energy is developed to obtain operating conditions for which the total (capital and operating) cost is a minimum. Both graphical and analytical methods are used in the thermodynamic optimization to determine the optimum flash temperature. The graphical method is based on thermodynamic data provided by an i-s (enthalpy-entropy) diagram for water and steam, in the analytical method, first and second order approximations (first and second degree polynomial approximations), are used for the functions which express enthalpy differences in terms of flash temperature. Numerical results are provided by computer programs developed for the analytical method. These results cover the temperature range normally encountered in practice. In the case of the single-flash cycle, results from both the graphical and analytical method using the first order approximation indicate the same optimum flash temperature; however, the correction factor resulting from the second order approximation improves the value of the temperature by a correction of about -2 ° C. Optimum flash temperatures for the double-flash cycle are similarly determined using the analytical method with a first order approximation. In the economic optimization of space heating systems, the analysis is made on the basis of the annual total cost per unit area of wall surface. It takes into account the cost of the geothermal fluid, cost of wall insulation, and heat exchanger cost. For a specific case where the inlet temperature to the heat exchanger is at 100° C and the outlet temperature at 28° C, the minimum annual cost to maintain a space at 20°C with an outside temperature of -l0°C is given at $0.0257 per square meter of wall area while the optimum thickness for the wall insulation is 0. 126 meter. Additional improvement in the optimization of flash temperature can be made by using a second order approximation method for the double-flash power cycle. Close

• 9. [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

• 10. [Article] Temperature dependence of dark current in a CCD

  We present data for dark current of a back-illuminated CCD over the temperature range of 222 to 291 K. Using an Arrhenius law, we found that the analysis of the data leads to the relation between the prefactor ...

  Citation × Citation Citation Abstract Copy Title: Temperature dependence of dark current in a CCD Author: Widenhorn, Ralf, Blouke, Morley M., Weber, Alexander, Rest, Armin, Bodegom, Erik Year: 2002 We present data for dark current of a back-illuminated CCD over the temperature range of 222 to 291 K. Using an Arrhenius law, we found that the analysis of the data leads to the relation between the prefactor and the apparent activation energy as described by the Meyer-Neldel rule. However, a more detailed analysis shows that the activation energy for the dark current changes in the temperature range investigated. This transition can be explained by the larger relative importance at high temperatures of the diffusion dark current and at low temperatures by the depletion dark current. The diffusion dark current, characterized by the band gap of silicon, is uniform for all pixels. At low temperatures, the depletion dark current, characterized by half the band gap, prevails, but it varies for different pixels. Dark current spikes are pronounced at low temperatures and can be explained by large concentrations of deep level impurities in those particular pixels. We show that fitting the data with the impurity concentration as the only variable can explain the dark current characteristics of all the pixels on the chip. Title: Temperature dependence of dark current in a CCD Author: Widenhorn, Ralf, Blouke, Morley M., Weber, Alexander, Rest, Armin, Bodegom, Erik Year: 2002 We present data for dark current of a back-illuminated CCD over the temperature range of 222 to 291 K. Using an Arrhenius law, we found that the analysis of the data leads to the relation between the prefactor and the apparent activation energy as described by the Meyer-Neldel rule. However, a more detailed analysis shows that the activation energy for the dark current changes in the temperature range investigated. This transition can be explained by the larger relative importance at high temperatures of the diffusion dark current and at low temperatures by the depletion dark current. The diffusion dark current, characterized by the band gap of silicon, is uniform for all pixels. At low temperatures, the depletion dark current, characterized by half the band gap, prevails, but it varies for different pixels. Dark current spikes are pronounced at low temperatures and can be explained by large concentrations of deep level impurities in those particular pixels. We show that fitting the data with the impurity concentration as the only variable can explain the dark current characteristics of all the pixels on the chip. Close

• 11. [Article] Response of Sagebrush Steppe Species to Elevated CO2 and Soil Temperature

  Elevated atmospheric CO2 may cause long-term changes in the productivity and species composition of the sagebrush steppe. Few studies, however, have evaluated the effects of increased CO2 on growth and ...

  Citation × Citation Citation Abstract Copy Title: Response of Sagebrush Steppe Species to Elevated CO2 and Soil Temperature Author: Lucash, Melissa S., Farnsworth, Blake, Winner, William E. Year: 2005 Elevated atmospheric CO2 may cause long-term changes in the productivity and species composition of the sagebrush steppe. Few studies, however, have evaluated the effects of increased CO2 on growth and physiology of species important to this ecosystem. Since the response of plants to elevated CO2 may be limited by environmental factors, soil temperature was also examined to determine if low soil temperatures limit CO2 response. To determine how CO2 and soil temperature affect the growth of species native to the sagebrush steppe, bottlebrush squirreltail [Elymus elymoides (Raf.) Swezey], Thurber needlegrass (Stipa thurberiana Piper), and Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle) were grown in ambient (374 mL L–1) or high (567 mL L–1) CO2 and low (13°C) or high (18°C) soil temperature for approximately 4 months. Although soil temperature affected the growth of squirreltail and needlegrass, temperature did not modify their response to elevated CO2. Total biomass of sagebrush was consistent across soil temperature and CO2 treatments, reflecting its slow-growing strategy. All 3 species had higher leaf water-use efficiency at elevated CO2 due to higher net photosynthesis and lower transpiration rates. We conclude that elevated CO2 and soil warming may increase the growth of grasses more than shrubs. Field studies in the sagebrush steppe are necessary to determine if differences in biomass, resulting from changes in CO2 and soil temperature, are exhibited in the field. Title: Response of Sagebrush Steppe Species to Elevated CO2 and Soil Temperature Author: Lucash, Melissa S., Farnsworth, Blake, Winner, William E. Year: 2005 Elevated atmospheric CO2 may cause long-term changes in the productivity and species composition of the sagebrush steppe. Few studies, however, have evaluated the effects of increased CO2 on growth and physiology of species important to this ecosystem. Since the response of plants to elevated CO2 may be limited by environmental factors, soil temperature was also examined to determine if low soil temperatures limit CO2 response. To determine how CO2 and soil temperature affect the growth of species native to the sagebrush steppe, bottlebrush squirreltail [Elymus elymoides (Raf.) Swezey], Thurber needlegrass (Stipa thurberiana Piper), and Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle) were grown in ambient (374 mL L–1) or high (567 mL L–1) CO2 and low (13°C) or high (18°C) soil temperature for approximately 4 months. Although soil temperature affected the growth of squirreltail and needlegrass, temperature did not modify their response to elevated CO2. Total biomass of sagebrush was consistent across soil temperature and CO2 treatments, reflecting its slow-growing strategy. All 3 species had higher leaf water-use efficiency at elevated CO2 due to higher net photosynthesis and lower transpiration rates. We conclude that elevated CO2 and soil warming may increase the growth of grasses more than shrubs. Field studies in the sagebrush steppe are necessary to determine if differences in biomass, resulting from changes in CO2 and soil temperature, are exhibited in the field. Close

• 12. [Article] Seasonal Patterns of Photosynthesis in Douglas Fir Seedlings During the Third and Fourth Year of Exposure to Elevated CO2 and Temperature

  The interactive effects of elevated atmospheric CO2 and temperature on seasonal patterns of photosynthesis in Douglas fir (Psuedotsuga menziesii (Mirb.) Franco) seedlings were examined. Seedlings were ...

  Citation × Citation Citation Abstract Copy Title: Seasonal Patterns of Photosynthesis in Douglas Fir Seedlings During the Third and Fourth Year of Exposure to Elevated CO2 and Temperature Author: Lewis, James D., Lucash, Melissa S., Olszyk, David M., Tingey, David T. Year: 2001 The interactive effects of elevated atmospheric CO2 and temperature on seasonal patterns of photosynthesis in Douglas fir (Psuedotsuga menziesii (Mirb.) Franco) seedlings were examined. Seedlings were grown in sunlit chambers controlled to track either ambient (~400 p.p.m.) CO2 or ambient +200 p.p.m. CO2, and either ambient temperature or ambient +4 °C. Light-saturated net photosynthetic rates were measured approximately monthly over a 21 month period. Elevated CO2 increased net photosynthetic rates by an average of 21% across temperature treatments during both the 1996 hydrologic year, the third year of exposure, and the 1997 hydrologic year. Elevated mean annual temperature increased net photosynthetic rates by an average of 33% across CO2 treatments during both years. Seasonal temperature changes also affected net photosynthetic rates. Across treatments, net photosynthetic rates were highest in the spring and autumn, and lowest in July, August and December–January. Seasonal increases in temperature were not correlated with increases in the relative photosynthetic response to elevated CO2. Seasonal shifts in the photosynthetic temperature optimum reduced temperature effects on the relative response to elevated CO2. These results suggest that the effects of elevated CO2 on net photosynthetic rates in Douglas fir are largely independent of temperature. Title: Seasonal Patterns of Photosynthesis in Douglas Fir Seedlings During the Third and Fourth Year of Exposure to Elevated CO2 and Temperature Author: Lewis, James D., Lucash, Melissa S., Olszyk, David M., Tingey, David T. Year: 2001 The interactive effects of elevated atmospheric CO2 and temperature on seasonal patterns of photosynthesis in Douglas fir (Psuedotsuga menziesii (Mirb.) Franco) seedlings were examined. Seedlings were grown in sunlit chambers controlled to track either ambient (~400 p.p.m.) CO2 or ambient +200 p.p.m. CO2, and either ambient temperature or ambient +4 °C. Light-saturated net photosynthetic rates were measured approximately monthly over a 21 month period. Elevated CO2 increased net photosynthetic rates by an average of 21% across temperature treatments during both the 1996 hydrologic year, the third year of exposure, and the 1997 hydrologic year. Elevated mean annual temperature increased net photosynthetic rates by an average of 33% across CO2 treatments during both years. Seasonal temperature changes also affected net photosynthetic rates. Across treatments, net photosynthetic rates were highest in the spring and autumn, and lowest in July, August and December–January. Seasonal increases in temperature were not correlated with increases in the relative photosynthetic response to elevated CO2. Seasonal shifts in the photosynthetic temperature optimum reduced temperature effects on the relative response to elevated CO2. These results suggest that the effects of elevated CO2 on net photosynthetic rates in Douglas fir are largely independent of temperature. Close

• 13. [Article] Analysis and prediction of the water temperature of the McKenzie River, Oregon using the equilibrium temperature approach

  A one dimensional, steady flow, unsteady temperature model is used to evaluate the effects of two U.S. Army Corps of Engineers (COE) dams and resulting reservoirs on hourly water temperatures of the mainstem ...

  Citation × Citation Citation Abstract Copy Title: Analysis and prediction of the water temperature of the McKenzie River, Oregon using the equilibrium temperature approach Author: Hansen, R. Peder Year: 1986 A one dimensional, steady flow, unsteady temperature model is used to evaluate the effects of two U.S. Army Corps of Engineers (COE) dams and resulting reservoirs on hourly water temperatures of the mainstem McKenzie River from Delta Park (RM 62.1) to Leaburg Dam (RM 38.8). Both COE projects are on tributaries to the McKenzie River and at present have only bottom withdrawl capabilities. Title: Analysis and prediction of the water temperature of the McKenzie River, Oregon using the equilibrium temperature approach Author: Hansen, R. Peder Year: 1986 A one dimensional, steady flow, unsteady temperature model is used to evaluate the effects of two U.S. Army Corps of Engineers (COE) dams and resulting reservoirs on hourly water temperatures of the mainstem McKenzie River from Delta Park (RM 62.1) to Leaburg Dam (RM 38.8). Both COE projects are on tributaries to the McKenzie River and at present have only bottom withdrawl capabilities. Close

• 14. [Article] Thermal Ecology and Movement in the Leopard Lizard, Gambelia Wislizeni, Baird and Girard

  Thermal ecology and movement of the Leopard Lizard, G. wistizeniwere studied at Frog Spring, adjacent to the Alvord Desert, and at various locations throughout the Alvord Basin. Seasonal activity is known ...

  Citation × Citation Citation Abstract Copy Title: Thermal Ecology and Movement in the Leopard Lizard, Gambelia Wislizeni, Baird and Girard Author: Abts, Marvin Lynn Year: 1976 Thermal ecology and movement of the Leopard Lizard, G. wistizeniwere studied at Frog Spring, adjacent to the Alvord Desert, and at various locations throughout the Alvord Basin. Seasonal activity is known to occur from early May to mid-October, but abundance. gradually decreases after late July. During favorable late spring, and summer weather lizards exhibit a bimodal pattern of diel activity with some activity occurring at all hours of the day between 0600 and 1800 H. At other times activity was unimodal. Emergence was apparently largely temperature dependent and did not occur until sand temperature approximated 21°C. Retreat appeared to be temperature independent, and was initiated by exogenous or endogenous stimuli at sand temperatures often above body temperatures acceptable for normal activity. For the period of study, juveniles exhibited diel activity patterns similar to adults, and were found during all hours in which adults were encountered. Body temperatures of field active lizards, largely affected by the immediate weather conditions, , ranged from 18.6° to 43.4°C. Because of a variety of thermoregulatory response (changes in location, posture, and orientation, color change, burrowing, shade-seeking, and panting), even during unfavorable weather conditions, most body temperatures fell within a narrower range. Nonetheless, the ability of field active lizards to precisely thermoregulate was limited, and the levels of body temperature maintained usually encompassed a broader range than those maintained in a thermal gradient. The mean body temperature of field active lizards during favorable weather conditions, and that of active lizards in a thermal gradient, did not differ significantly, and seemed to indicate a narrow range of body temperature preference. However, prevailing weather conditions were frequently unfavorable, thus limiting the extent of time during which selection of preferred body temperature could occur. Consequently, though activity depended on the attainment of certain temperature levels, G. wislizeni was forced to adapt to a broader range of body temperatures when performing most routine tasks. The necessity of precision thermoregulation is unclear, but apparently physiological efficiency was not greatly diminished over the broad range of body temperatures fiefd active lizards were often accepting. Relatively speaking, movement in G. wislizeni was extensive. Adult males occupied an average area more than twice the size of adult females and juveniles. Plotted polygons, constructed from sighting points, tended to be elongate. The extent to which lizards occupied a definite home range was uncertain. Adult males , continuously expanding the area occupied, probably lacked a home range. Adult females, demonstrating . little area expansion, perhaps maintained a home range. Territoriality by means of intraspecific display or aggression appeared negligible in G. wislizeni.Adult males did not demonstrate such behavior toward one another . Based on a limited extent of area overlap, adult females may have exhibited territoriality toward members of their sex. Movement per hour revealed results similar to area occupied, with adult males traveling an average distance of nearly three times as great as adult females and juveniles. Greatest distances frequently coincided with peak diel activity. Individual moves were frequent in adult males and juveniles, but infrequent in ~ adult females. Adult female long moves were similar in distance to adult males, but exogenous stimuli perhaps linked with home range maintenance restricted the frequency of such jaunts. Movement in G. wislizeni appeared independent of environmental thermal conditions when body temperature was within the range acceptable for normal activity. Diel movement appeared to be random in the species. Seasonal movement in juveniles, based on dispersion data, appeared directional. Title: Thermal Ecology and Movement in the Leopard Lizard, Gambelia Wislizeni, Baird and Girard Author: Abts, Marvin Lynn Year: 1976 Thermal ecology and movement of the Leopard Lizard, G. wistizeniwere studied at Frog Spring, adjacent to the Alvord Desert, and at various locations throughout the Alvord Basin. Seasonal activity is known to occur from early May to mid-October, but abundance. gradually decreases after late July. During favorable late spring, and summer weather lizards exhibit a bimodal pattern of diel activity with some activity occurring at all hours of the day between 0600 and 1800 H. At other times activity was unimodal. Emergence was apparently largely temperature dependent and did not occur until sand temperature approximated 21°C. Retreat appeared to be temperature independent, and was initiated by exogenous or endogenous stimuli at sand temperatures often above body temperatures acceptable for normal activity. For the period of study, juveniles exhibited diel activity patterns similar to adults, and were found during all hours in which adults were encountered. Body temperatures of field active lizards, largely affected by the immediate weather conditions, , ranged from 18.6° to 43.4°C. Because of a variety of thermoregulatory response (changes in location, posture, and orientation, color change, burrowing, shade-seeking, and panting), even during unfavorable weather conditions, most body temperatures fell within a narrower range. Nonetheless, the ability of field active lizards to precisely thermoregulate was limited, and the levels of body temperature maintained usually encompassed a broader range than those maintained in a thermal gradient. The mean body temperature of field active lizards during favorable weather conditions, and that of active lizards in a thermal gradient, did not differ significantly, and seemed to indicate a narrow range of body temperature preference. However, prevailing weather conditions were frequently unfavorable, thus limiting the extent of time during which selection of preferred body temperature could occur. Consequently, though activity depended on the attainment of certain temperature levels, G. wislizeni was forced to adapt to a broader range of body temperatures when performing most routine tasks. The necessity of precision thermoregulation is unclear, but apparently physiological efficiency was not greatly diminished over the broad range of body temperatures fiefd active lizards were often accepting. Relatively speaking, movement in G. wislizeni was extensive. Adult males occupied an average area more than twice the size of adult females and juveniles. Plotted polygons, constructed from sighting points, tended to be elongate. The extent to which lizards occupied a definite home range was uncertain. Adult males , continuously expanding the area occupied, probably lacked a home range. Adult females, demonstrating . little area expansion, perhaps maintained a home range. Territoriality by means of intraspecific display or aggression appeared negligible in G. wislizeni.Adult males did not demonstrate such behavior toward one another . Based on a limited extent of area overlap, adult females may have exhibited territoriality toward members of their sex. Movement per hour revealed results similar to area occupied, with adult males traveling an average distance of nearly three times as great as adult females and juveniles. Greatest distances frequently coincided with peak diel activity. Individual moves were frequent in adult males and juveniles, but infrequent in ~ adult females. Adult female long moves were similar in distance to adult males, but exogenous stimuli perhaps linked with home range maintenance restricted the frequency of such jaunts. Movement in G. wislizeni appeared independent of environmental thermal conditions when body temperature was within the range acceptable for normal activity. Diel movement appeared to be random in the species. Seasonal movement in juveniles, based on dispersion data, appeared directional. Close

• 15. [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

• 16. [Article] Stomatal Responses of Douglas-Fir Seedlings to Elevated Carbon Dioxide and Temperature During the Third and Fourth Years of Exposure

  Two major components of climate change, increasing atmospheric [CO2] and increasing temperature, may substantially alter the effects of water availability to plants through effects on the rate of water ...

  Citation × Citation Citation Abstract Copy Title: Stomatal Responses of Douglas-Fir Seedlings to Elevated Carbon Dioxide and Temperature During the Third and Fourth Years of Exposure Author: Lewis, James D., Lucash, Melissa S., Olszyk, David M., Tingey, David T. Year: 2002 Two major components of climate change, increasing atmospheric [CO2] and increasing temperature, may substantially alter the effects of water availability to plants through effects on the rate of water loss from leaves. We examined the interactive effects of elevated [CO2] and temperature on seasonal patterns of stomatal conductance (gs), transpiration (E) and instantaneous transpiration efficiency (ITE) in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings. Seedlings were grown in sunlit chambers at either ambient CO2 (AC) or ambient + 180 µmol mol-1 CO2 (EC), and at ambient temperature (AT) or ambient + 3.5° C (ET) in a full-factorial design. Needle gas exchange at the target growth conditions was measured approximately monthly over 21 months. Across the study period and across temperature treatments, growth in elevated [CO2] decreased E by an average of 12% and increased ITE by an average of 46%. The absolute reduction of E associated with elevated [CO2] significantly increased with seasonal increases in the needle-to-air vapour pressure deficit (D). Across CO2 treatments, growth in elevated temperature increased E an average of 37%, and did not affect ITE. Combined, growth in elevated [CO2] and elevated temperature increased E an average of 19% compared with the ACAT treatment. The CO2 supply and growth temperature did not significantly affect stomatal sensitivity to D or the relationship between gs and net photosynthetic rates. This study suggests that elevated [CO2] may not completely ameliorate the effect of elevated temperature on E, and that climate change may substantially alter needle-level water loss and water use efficiency of Douglas-fir seedlings. Title: Stomatal Responses of Douglas-Fir Seedlings to Elevated Carbon Dioxide and Temperature During the Third and Fourth Years of Exposure Author: Lewis, James D., Lucash, Melissa S., Olszyk, David M., Tingey, David T. Year: 2002 Two major components of climate change, increasing atmospheric [CO2] and increasing temperature, may substantially alter the effects of water availability to plants through effects on the rate of water loss from leaves. We examined the interactive effects of elevated [CO2] and temperature on seasonal patterns of stomatal conductance (gs), transpiration (E) and instantaneous transpiration efficiency (ITE) in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings. Seedlings were grown in sunlit chambers at either ambient CO2 (AC) or ambient + 180 µmol mol-1 CO2 (EC), and at ambient temperature (AT) or ambient + 3.5° C (ET) in a full-factorial design. Needle gas exchange at the target growth conditions was measured approximately monthly over 21 months. Across the study period and across temperature treatments, growth in elevated [CO2] decreased E by an average of 12% and increased ITE by an average of 46%. The absolute reduction of E associated with elevated [CO2] significantly increased with seasonal increases in the needle-to-air vapour pressure deficit (D). Across CO2 treatments, growth in elevated temperature increased E an average of 37%, and did not affect ITE. Combined, growth in elevated [CO2] and elevated temperature increased E an average of 19% compared with the ACAT treatment. The CO2 supply and growth temperature did not significantly affect stomatal sensitivity to D or the relationship between gs and net photosynthetic rates. This study suggests that elevated [CO2] may not completely ameliorate the effect of elevated temperature on E, and that climate change may substantially alter needle-level water loss and water use efficiency of Douglas-fir seedlings. Close

• 17. [Article] Morphogenesis of Douglas Fir Buds is Altered at Elevated Temperature but not at Elevated CO2

  Global climatic change as expressed by increased CO2 and temperature has the potential for dramatic effects on trees. To determine what its effects may be on Pacific Northwest forests, Douglas-fir (Pseudotsuga ...

  Citation × Citation Citation Abstract Copy Title: Morphogenesis of Douglas Fir Buds is Altered at Elevated Temperature but not at Elevated CO2 Author: Apple, Martha E., Lucash, Melissa S., Olszyk, David M., Tingey, David T. Year: 1998 Global climatic change as expressed by increased CO2 and temperature has the potential for dramatic effects on trees. To determine what its effects may be on Pacific Northwest forests, Douglas-fir (Pseudotsuga menziesii ) seedlings were grown in sun-lit controlled environment chambers at ambient or elevated (+4°C above ambient) temperature, and at ambient or elevated (+200 ppm above ambient) CO2. In 1995–1996 and 1996–1997, elevated CO2 had no effect on vegetative bud morphology, while the following unusual morphological characteristics were found with greater frequency at elevated temperature than at ambient: rosetted buds with reflexed and loosened outer scales, convoluted inner scales, clusters of small buds, needles elongating between scales, needle primordia with white, hyaline apical extensions, and buds with hardened scales inside of unbroken buds. Buds became rosetted in elevated temperature chambers after temperatures exceeded 40°C in July, 1996. Rosettes were induced within 48-h in buds placed in a 40°C oven; fewer rosettes formed at 20°C. Induction was reversible in buds transferred from 40 to 20°C, implying that rosetting is a physical rather than a growth phenomenon. It appears that rosettes form after long-term exposure to elevated temperature and after shorter periods of exposure to intense heat. Elevated temperature influences bud morphology and may therefore influence the overall branching structure of Douglas-fir seedlings. Title: Morphogenesis of Douglas Fir Buds is Altered at Elevated Temperature but not at Elevated CO2 Author: Apple, Martha E., Lucash, Melissa S., Olszyk, David M., Tingey, David T. Year: 1998 Global climatic change as expressed by increased CO2 and temperature has the potential for dramatic effects on trees. To determine what its effects may be on Pacific Northwest forests, Douglas-fir (Pseudotsuga menziesii ) seedlings were grown in sun-lit controlled environment chambers at ambient or elevated (+4°C above ambient) temperature, and at ambient or elevated (+200 ppm above ambient) CO2. In 1995–1996 and 1996–1997, elevated CO2 had no effect on vegetative bud morphology, while the following unusual morphological characteristics were found with greater frequency at elevated temperature than at ambient: rosetted buds with reflexed and loosened outer scales, convoluted inner scales, clusters of small buds, needles elongating between scales, needle primordia with white, hyaline apical extensions, and buds with hardened scales inside of unbroken buds. Buds became rosetted in elevated temperature chambers after temperatures exceeded 40°C in July, 1996. Rosettes were induced within 48-h in buds placed in a 40°C oven; fewer rosettes formed at 20°C. Induction was reversible in buds transferred from 40 to 20°C, implying that rosetting is a physical rather than a growth phenomenon. It appears that rosettes form after long-term exposure to elevated temperature and after shorter periods of exposure to intense heat. Elevated temperature influences bud morphology and may therefore influence the overall branching structure of Douglas-fir seedlings. Close

• 18. [Article] Daily Temperature Fluctuations Unpredictably Influence Developmental Rate and Morphology at a Critical Early Larval Stage in a Frog

  Background: Environmental temperature has profound consequences for early amphibian development and many field and laboratory studies have examined this. Most laboratory studies that have characterized ...

  Citation × Citation Citation Abstract Copy Title: Daily Temperature Fluctuations Unpredictably Influence Developmental Rate and Morphology at a Critical Early Larval Stage in a Frog Author: Arrighi, Juliana M., Lencer, Ezra S., Jukar, Advait, Park, Daesik, Phillips, Patrick C., Kaplan, Robert H. Year: 2013 Background: Environmental temperature has profound consequences for early amphibian development and many field and laboratory studies have examined this. Most laboratory studies that have characterized the influence of temperature on development in amphibians have failed to incorporate the realities of diel temperature fluctuations (DTF), which can be considerable for pond-breeding amphibians. Results: We evaluated the effects of different ecologically relevant ranges of DTF compared with effects of constant temperatures on development of embryos and larvae of the Korean fire-bellied toad (Bombina orientalis). We constructed thermal reaction norms for developmental stage, snout- vent length, and tail length by fitting a Gompertz-Gaussian function to measurements taken from embryos after 66 hours of development in 12 different constant temperature environments between 14°C and 36°C. We used these reaction norms as null models to test the hypothesis that developmental effects of DTF are more than the sum of average constant temperature effects over the distribution of temperatures experienced. We predicted from these models that growth and differentiation would be positively correlated with average temperature at low levels of DTF but not at higher levels of DTF. We tested our prediction in the laboratory by rearing B. orientalis embryos at three average temperatures (20°C, 24°C, and 28°C) and four levels of thermal variation (0°C, 6°C, 13°C, and 20°C). Several of the observed responses to DTF were significantly different from both predictions of the model and from responses in constant temperature treatments at the same average temperatures. At an average temperature of 24°C, only the highest level of DTF affected differentiation and growth rates, but at both cooler and warmer average temperatures, moderate DTF was enough to slow developmental and tail growth rates. Conclusions: These results demonstrate that both the magnitude of DTF range and thermal averages need to be considered simultaneously when parsing the effects of changing thermal environments on complex developmental responses, particularly when they have potential functional and adaptive significance. Title: Daily Temperature Fluctuations Unpredictably Influence Developmental Rate and Morphology at a Critical Early Larval Stage in a Frog Author: Arrighi, Juliana M., Lencer, Ezra S., Jukar, Advait, Park, Daesik, Phillips, Patrick C., Kaplan, Robert H. Year: 2013 Background: Environmental temperature has profound consequences for early amphibian development and many field and laboratory studies have examined this. Most laboratory studies that have characterized the influence of temperature on development in amphibians have failed to incorporate the realities of diel temperature fluctuations (DTF), which can be considerable for pond-breeding amphibians. Results: We evaluated the effects of different ecologically relevant ranges of DTF compared with effects of constant temperatures on development of embryos and larvae of the Korean fire-bellied toad (Bombina orientalis). We constructed thermal reaction norms for developmental stage, snout- vent length, and tail length by fitting a Gompertz-Gaussian function to measurements taken from embryos after 66 hours of development in 12 different constant temperature environments between 14°C and 36°C. We used these reaction norms as null models to test the hypothesis that developmental effects of DTF are more than the sum of average constant temperature effects over the distribution of temperatures experienced. We predicted from these models that growth and differentiation would be positively correlated with average temperature at low levels of DTF but not at higher levels of DTF. We tested our prediction in the laboratory by rearing B. orientalis embryos at three average temperatures (20°C, 24°C, and 28°C) and four levels of thermal variation (0°C, 6°C, 13°C, and 20°C). Several of the observed responses to DTF were significantly different from both predictions of the model and from responses in constant temperature treatments at the same average temperatures. At an average temperature of 24°C, only the highest level of DTF affected differentiation and growth rates, but at both cooler and warmer average temperatures, moderate DTF was enough to slow developmental and tail growth rates. Conclusions: These results demonstrate that both the magnitude of DTF range and thermal averages need to be considered simultaneously when parsing the effects of changing thermal environments on complex developmental responses, particularly when they have potential functional and adaptive significance. Close

• 19. [Article] The Relationship Between Precipitation and Temperature Over the Contiguous United States

  The correlation between monthly total precipitation and monthly mean temperature over the 80-year period from 1905 to 1984 at nearly 1000 stations in the contiguous United States was calculated and analyzed. ...

  Citation × Citation Citation Abstract Copy Title: The Relationship Between Precipitation and Temperature Over the Contiguous United States Author: Zhao, Weining, Khalil, M. A. K. Year: 1993 The correlation between monthly total precipitation and monthly mean temperature over the 80-year period from 1905 to 1984 at nearly 1000 stations in the contiguous United States was calculated and analyzed. Both local and field significances were tested by using statistical methods. Areas of both negative and positive precipitation-temperature correlations were found. Over most of the United States, summer precipitation and temperature were negatively correlated, which indicates that warm summers tended to be dryer. This is particularly true in the central and southern Great Plains. The area south of the Great Lakes covering the eastern portion of the Corn Belt was the only major area where a significant positive correlation was found in winter. Title: The Relationship Between Precipitation and Temperature Over the Contiguous United States Author: Zhao, Weining, Khalil, M. A. K. Year: 1993 The correlation between monthly total precipitation and monthly mean temperature over the 80-year period from 1905 to 1984 at nearly 1000 stations in the contiguous United States was calculated and analyzed. Both local and field significances were tested by using statistical methods. Areas of both negative and positive precipitation-temperature correlations were found. Over most of the United States, summer precipitation and temperature were negatively correlated, which indicates that warm summers tended to be dryer. This is particularly true in the central and southern Great Plains. The area south of the Great Lakes covering the eastern portion of the Corn Belt was the only major area where a significant positive correlation was found in winter. Close

• 20. [Article] Optical properties of β″-(ET)2SF5CH2CF2SO3: A layered molecular superconductor with large discrete counterions

  We report the polarized infrared and optical reflectance of β″-(ET)₂SF₅CH₂CF₂SO₃ as a function of temperature. This fully organic superconductor displays weakly metallic behavior over the entire temperature ...

  Citation × Citation Citation Abstract Copy Title: Optical properties of β″-(ET)2SF5CH2CF2SO3: A layered molecular superconductor with large discrete counterions Author: Dong, J., Musfeldt, J. L., Schlueter, J. A., Williams, Jack M., Nixon, P. G., Winter, Rolf Walter, Gard, Gary L. Year: 1999 We report the polarized infrared and optical reflectance of β″-(ET)₂SF₅CH₂CF₂SO₃ as a function of temperature. This fully organic superconductor displays weakly metallic behavior over the entire temperature range of our investigation. The electronic properties present several unusual features including the lack of a conventional free carrier (Drude) response at low temperature, infrared localization phenomena, and an unexpected temperature dependence of the oscillator strength. Similar behavior is observed in other β and β″ superconductors above Tc, suggesting that this class of compounds is very close to a metal→insulator transition where electronic correlations are important and the Drude response carries very little spectral weight. Vibronic features increase in intensity with decreasing temperature in the infrared, as expected. The temperature dependence of key anion vibrational modes are discussed in terms of intermolecular hydrogen bonding within the anion pocket. [S0163-1829(99)04330-1] Title: Optical properties of β″-(ET)2SF5CH2CF2SO3: A layered molecular superconductor with large discrete counterions Author: Dong, J., Musfeldt, J. L., Schlueter, J. A., Williams, Jack M., Nixon, P. G., Winter, Rolf Walter, Gard, Gary L. Year: 1999 We report the polarized infrared and optical reflectance of β″-(ET)₂SF₅CH₂CF₂SO₃ as a function of temperature. This fully organic superconductor displays weakly metallic behavior over the entire temperature range of our investigation. The electronic properties present several unusual features including the lack of a conventional free carrier (Drude) response at low temperature, infrared localization phenomena, and an unexpected temperature dependence of the oscillator strength. Similar behavior is observed in other β and β″ superconductors above Tc, suggesting that this class of compounds is very close to a metal→insulator transition where electronic correlations are important and the Drude response carries very little spectral weight. Vibronic features increase in intensity with decreasing temperature in the infrared, as expected. The temperature dependence of key anion vibrational modes are discussed in terms of intermolecular hydrogen bonding within the anion pocket. [S0163-1829(99)04330-1] Close

• 21. [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

• 22. [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

• 23. [Article] Surface-enhanced Raman scattering at elevated temperatures

  The effect on surface-enhanced Raman scattering due to the increase in temperature of the metallic substrate is studied via a simple model for physisorbed molecules. Surface roughness is represented by ...

  Citation × Citation Citation Abstract Copy Title: Surface-enhanced Raman scattering at elevated temperatures Author: Leung, P.T., Hider, M. H., Sánchez, Erik J. Year: 1996 The effect on surface-enhanced Raman scattering due to the increase in temperature of the metallic substrate is studied via a simple model for physisorbed molecules. Surface roughness is represented by a spherical or spheroidal island, and the temperature effects on the surface plasmon are accounted for via a slightly modified Ujihara model. It is found that the enhancement ratio in general decreases as substrate temperature increases. For noble metals like silver, this temperature effect is particularly pronounced at scattering frequencies close to that of the surface-plasmon resonance; and for frequencies well below the surface plasmon frequency, the enhancement ratio is relatively insensitive to the change of substrate temperature. A tentative explanation is provided for our modeling results, and the implications from these results are discussed. Title: Surface-enhanced Raman scattering at elevated temperatures Author: Leung, P.T., Hider, M. H., Sánchez, Erik J. Year: 1996 The effect on surface-enhanced Raman scattering due to the increase in temperature of the metallic substrate is studied via a simple model for physisorbed molecules. Surface roughness is represented by a spherical or spheroidal island, and the temperature effects on the surface plasmon are accounted for via a slightly modified Ujihara model. It is found that the enhancement ratio in general decreases as substrate temperature increases. For noble metals like silver, this temperature effect is particularly pronounced at scattering frequencies close to that of the surface-plasmon resonance; and for frequencies well below the surface plasmon frequency, the enhancement ratio is relatively insensitive to the change of substrate temperature. A tentative explanation is provided for our modeling results, and the implications from these results are discussed. Close

• 24. [Article] Computation of dark frames in digital imagers

  Dark current is caused by electrons that are thermally exited into the conduction band. These electrons are collected by the well of the CCD and add a false signal to the chip. We will present an algorithm ...

  Citation × Citation Citation Abstract Copy Title: Computation of dark frames in digital imagers Author: Widenhorn, Ralf, Rest, Armin, Blouke, Morley M., Berry, Richard L., Bodegom, Erik Year: 2007 Dark current is caused by electrons that are thermally exited into the conduction band. These electrons are collected by the well of the CCD and add a false signal to the chip. We will present an algorithm that automatically corrects for dark current. It uses a calibration protocol to characterize the image sensor for different temperatures. For a given exposure time, the dark current of every pixel is characteristic of a specific temperature. The dark current of every pixel can therefore be used as an indicator of the temperature. Hot pixels have the highest signal-to-noise ratio and are the best temperature sensors. We use the dark current of a several hundred hot pixels to sense the chip temperature and predict the dark current of all pixels on the chip. Dark current computation is not a new concept, but our approach is unique. Some advantages of our method include applicability for poorly temperature-controlled camera systems and the possibility of ex post facto dark current correction. Title: Computation of dark frames in digital imagers Author: Widenhorn, Ralf, Rest, Armin, Blouke, Morley M., Berry, Richard L., Bodegom, Erik Year: 2007 Dark current is caused by electrons that are thermally exited into the conduction band. These electrons are collected by the well of the CCD and add a false signal to the chip. We will present an algorithm that automatically corrects for dark current. It uses a calibration protocol to characterize the image sensor for different temperatures. For a given exposure time, the dark current of every pixel is characteristic of a specific temperature. The dark current of every pixel can therefore be used as an indicator of the temperature. Hot pixels have the highest signal-to-noise ratio and are the best temperature sensors. We use the dark current of a several hundred hot pixels to sense the chip temperature and predict the dark current of all pixels on the chip. Dark current computation is not a new concept, but our approach is unique. Some advantages of our method include applicability for poorly temperature-controlled camera systems and the possibility of ex post facto dark current correction. Close

• 25. [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

• 26. [Article] The Influence of Ambient Temperature on Green Roof R-values

  Green roofs can be an effective and appealing way to increase the energy efficiency of buildings by providing active insulation. As plants in the green roof transpire, there is a reduction in heat flux ...

  Citation × Citation Citation Abstract Copy Title: The Influence of Ambient Temperature on Green Roof R-values Author: Cox, Bryce Kevin Year: 2010 Green roofs can be an effective and appealing way to increase the energy efficiency of buildings by providing active insulation. As plants in the green roof transpire, there is a reduction in heat flux that is conducted through the green roof. The R-value, or thermal resistance, of a green roof is an effective measurement of thermal performance because it can be easily included in building energy calculations applicable to many different buildings and situations. The purpose of this study was to determine if an increase in ambient temperature would cause an increase in the R-value of green roofs. Test trays containing green roof materials were tested in a low speed wind tunnel equipped to determine the R-value of the trays. Three different plant species were tested in this study, ryegrass (Lolium perenne), sedum (Sedum hispanicum), and vinca (Vinca minor). For each test in this study the relative humidity was maintained at 45% and the soil was saturated with water. The trays were tested at four different ambient temperatures, ranging from room temperature to 120ºF. The resulting R-values for sedum ranged from 1.37 to 3.28 ft²h°F/BTU, for ryegrass the R-values ranged from 2.15 to 3.62 ft²h°F/BTU, and for vinca the R-values ranged from 3.15 to 5.19 ft²h°F/BTU. The average R-value for all the tests in this study was 3.20 ft²h°F/BTU. The results showed an increase in R-value with increasing temperature. Applying an ANOVA analysis to the data, the relationship between temperature and R-value for all three plant species was found to be statistically significant. Title: The Influence of Ambient Temperature on Green Roof R-values Author: Cox, Bryce Kevin Year: 2010 Green roofs can be an effective and appealing way to increase the energy efficiency of buildings by providing active insulation. As plants in the green roof transpire, there is a reduction in heat flux that is conducted through the green roof. The R-value, or thermal resistance, of a green roof is an effective measurement of thermal performance because it can be easily included in building energy calculations applicable to many different buildings and situations. The purpose of this study was to determine if an increase in ambient temperature would cause an increase in the R-value of green roofs. Test trays containing green roof materials were tested in a low speed wind tunnel equipped to determine the R-value of the trays. Three different plant species were tested in this study, ryegrass (Lolium perenne), sedum (Sedum hispanicum), and vinca (Vinca minor). For each test in this study the relative humidity was maintained at 45% and the soil was saturated with water. The trays were tested at four different ambient temperatures, ranging from room temperature to 120ºF. The resulting R-values for sedum ranged from 1.37 to 3.28 ft²h°F/BTU, for ryegrass the R-values ranged from 2.15 to 3.62 ft²h°F/BTU, and for vinca the R-values ranged from 3.15 to 5.19 ft²h°F/BTU. The average R-value for all the tests in this study was 3.20 ft²h°F/BTU. The results showed an increase in R-value with increasing temperature. Applying an ANOVA analysis to the data, the relationship between temperature and R-value for all three plant species was found to be statistically significant. Close

• 27. [Article] Effect of ethanol on thermoregulation in the goldfish, Carassius auratus

  In an attempt to elucidate the mechanism by which ethanol affects vertebrate thermoregulation, the effect of ethanol on temperature selection was studied in the goldfish, Carassius auratus. Ethanol was ...

  Citation × Citation Citation Abstract Copy Title: Effect of ethanol on thermoregulation in the goldfish, Carassius auratus Author: O'Connor, Candace Sharon Year: 1986 In an attempt to elucidate the mechanism by which ethanol affects vertebrate thermoregulation, the effect of ethanol on temperature selection was studied in the goldfish, Carassius auratus. Ethanol was administered to 10 to 15 g fish by mixing it in the water of a temperature gradient. The dose response curve was very steep between 0.5% (v/v) ethanol (no response) and 0.7% (significant lowering of selected temperature in treated fish). Fish were exposed to concentrations of ethanol as high as 1.7%, at which concentration most experimental fish lost their ability to swim upright in the water. At concentrations higher than 0.7%, the magnitude of the effect did not increase with increasing concentration of ethanol; treated animals continued to select temperatures about 2 C below temperatures selected by controls. Experiments alternating exposure to 1.0% ethanol and water showed that the rate of onset and disappearance of the ethanol effect was rapid (within 10 min). Other experiments exposing fish to 1.0% ethanol for up to 3 hr showed that the effect remained stable for this period of time. The thermoregulatory responses of fish are behavioral, and therefore relatively easy to observe and quantify. Ethanol produces a prompt, stable and reproducible depression of selected temperature in the goldfish. Because the temperature at which fish regulate is controlled by a central nervous system set point and not altered by effects on peripheral effector systems, it appears that ethanol may cause hypothermia in goldfish by directly acting to lower the set point. Title: Effect of ethanol on thermoregulation in the goldfish, Carassius auratus Author: O'Connor, Candace Sharon Year: 1986 In an attempt to elucidate the mechanism by which ethanol affects vertebrate thermoregulation, the effect of ethanol on temperature selection was studied in the goldfish, Carassius auratus. Ethanol was administered to 10 to 15 g fish by mixing it in the water of a temperature gradient. The dose response curve was very steep between 0.5% (v/v) ethanol (no response) and 0.7% (significant lowering of selected temperature in treated fish). Fish were exposed to concentrations of ethanol as high as 1.7%, at which concentration most experimental fish lost their ability to swim upright in the water. At concentrations higher than 0.7%, the magnitude of the effect did not increase with increasing concentration of ethanol; treated animals continued to select temperatures about 2 C below temperatures selected by controls. Experiments alternating exposure to 1.0% ethanol and water showed that the rate of onset and disappearance of the ethanol effect was rapid (within 10 min). Other experiments exposing fish to 1.0% ethanol for up to 3 hr showed that the effect remained stable for this period of time. The thermoregulatory responses of fish are behavioral, and therefore relatively easy to observe and quantify. Ethanol produces a prompt, stable and reproducible depression of selected temperature in the goldfish. Because the temperature at which fish regulate is controlled by a central nervous system set point and not altered by effects on peripheral effector systems, it appears that ethanol may cause hypothermia in goldfish by directly acting to lower the set point. Close

• 28. [Article] Climatology of Katabatic Winds in the McMurdo Dry Valleys, Southern Victoria Land, Antarctica

  Katabatic winds dramatically affect the climate of the McMurdo dry valleys, Antarctica. Winter wind events can increase local air temperatures by 30°C. The frequency of katabatic winds largely controls ...

  Citation × Citation Citation Abstract Copy Title: Climatology of Katabatic Winds in the McMurdo Dry Valleys, Southern Victoria Land, Antarctica Author: Nylen, Thomas H., Fountain, Andrew G., Doran, Peter T. Year: 2004 Katabatic winds dramatically affect the climate of the McMurdo dry valleys, Antarctica. Winter wind events can increase local air temperatures by 30°C. The frequency of katabatic winds largely controls winter (June to August) temperatures, increasing 1°C per 1% increase in katabatic frequency, and it overwhelms the effect of topographic elevation (lapse rate). Summer katabatic winds are important, but their influence on summer temperature is less. The spatial distribution of katabatic winds varies significantly. Winter events increase by 14% for every 10 km up valley toward the ice sheet, and summer events increase by 3%. The spatial distribution of katabatic frequency seems to be partly controlled by inversions. The relatively slow propagation speed of a katabatic front compared to its wind speed suggests a highly turbulent flow. The apparent wind skip (down-valley stations can be affected before up-valley ones) may be caused by flow deflection in the complex topography and by flow over inversions, which eventually break down. A strong return flow occurs at down-valley stations prior to onset of the katabatic winds and after they dissipate. Although the onset and termination of the katabatic winds are typically abrupt, elevated air temperatures remain for days afterward. We estimate that current frequencies of katabatic winds increase annual average temperatures by 0.7° to 2.2°C, depending on location. Seasonally, they increase (decrease) winter average temperatures (relative humidity) by 0.8° to 4.2° (−1.8 to −8.5%) and summer temperatures by 0.1° to 0.4°C (−0.9% to −4.1%). Long-term changes of dry valley air temperatures cannot be understood without knowledge of changes in katabatic winds. Title: Climatology of Katabatic Winds in the McMurdo Dry Valleys, Southern Victoria Land, Antarctica Author: Nylen, Thomas H., Fountain, Andrew G., Doran, Peter T. Year: 2004 Katabatic winds dramatically affect the climate of the McMurdo dry valleys, Antarctica. Winter wind events can increase local air temperatures by 30°C. The frequency of katabatic winds largely controls winter (June to August) temperatures, increasing 1°C per 1% increase in katabatic frequency, and it overwhelms the effect of topographic elevation (lapse rate). Summer katabatic winds are important, but their influence on summer temperature is less. The spatial distribution of katabatic winds varies significantly. Winter events increase by 14% for every 10 km up valley toward the ice sheet, and summer events increase by 3%. The spatial distribution of katabatic frequency seems to be partly controlled by inversions. The relatively slow propagation speed of a katabatic front compared to its wind speed suggests a highly turbulent flow. The apparent wind skip (down-valley stations can be affected before up-valley ones) may be caused by flow deflection in the complex topography and by flow over inversions, which eventually break down. A strong return flow occurs at down-valley stations prior to onset of the katabatic winds and after they dissipate. Although the onset and termination of the katabatic winds are typically abrupt, elevated air temperatures remain for days afterward. We estimate that current frequencies of katabatic winds increase annual average temperatures by 0.7° to 2.2°C, depending on location. Seasonally, they increase (decrease) winter average temperatures (relative humidity) by 0.8° to 4.2° (−1.8 to −8.5%) and summer temperatures by 0.1° to 0.4°C (−0.9% to −4.1%). Long-term changes of dry valley air temperatures cannot be understood without knowledge of changes in katabatic winds. Close

• 29. [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

• 30. [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

• 31. [Article] Temperature Dependence of Transcription Initiation in Archaea

  TFB1 and TFB2 are two Transcription Factor B (TFB) found in Pyrococcus furious (Pfu), a hyperthermophile archaeon. TFB1 is the primary TFB in Pfu, and highly conserved with eukaryotic TFIIB. TFB2 lacks ...

  Citation × Citation Citation Abstract Copy Title: Temperature Dependence of Transcription Initiation in Archaea Author: Wu, Ming-Hsiao Year: 2013 TFB1 and TFB2 are two Transcription Factor B (TFB) found in Pyrococcus furious (Pfu), a hyperthermophile archaeon. TFB1 is the primary TFB in Pfu, and highly conserved with eukaryotic TFIIB. TFB2 lacks some residues in B-reader region which interacts with promoter DNA and recognizes the transcription start site. Exposure to heat-shock increases the mRNA level of Pfu TFB2 in vivo; however, mRNA level of Pfu TFB1 stays the same. In Pfu, different TFBs may be used for regulating transcription. It is hypothesized that TFB2 is involved in heat-shock reaction and increases the transcription efficiency of heat-shock promoters. In our in vitro transcription assay, both TFB1 and TFB2 increase activity with increasing temperature, up to about 80C, and TFB1 has stronger activity in all temperatures and promoters. However, the rate of increase of TFB2 activity with increasing temperatures is greater than the rate for TFB1 in heat-shock promoters (PF0687 and Pf1616), compared to temperature-independent promoter (Pf1602) With Transcription Factor E (TFE) stabilizing the transcription preinitiation complex, transcription activities of TFB1 and TFB2 are enhanced, with TFB1 activity still stronger than TFB2 activity with all temperatures and promoters. TFE strongly enhances the activities of TFB2 in low temperatures, and makes the increasing rates of TFB1 and TFB2 become more similar in all promoters. These results indicate that TFB2 actives on heat-shock promoter, and TFE enhances TFB1 and TFB2's transcription activities and makes TFB2 acts more like TFB1. Title: Temperature Dependence of Transcription Initiation in Archaea Author: Wu, Ming-Hsiao Year: 2013 TFB1 and TFB2 are two Transcription Factor B (TFB) found in Pyrococcus furious (Pfu), a hyperthermophile archaeon. TFB1 is the primary TFB in Pfu, and highly conserved with eukaryotic TFIIB. TFB2 lacks some residues in B-reader region which interacts with promoter DNA and recognizes the transcription start site. Exposure to heat-shock increases the mRNA level of Pfu TFB2 in vivo; however, mRNA level of Pfu TFB1 stays the same. In Pfu, different TFBs may be used for regulating transcription. It is hypothesized that TFB2 is involved in heat-shock reaction and increases the transcription efficiency of heat-shock promoters. In our in vitro transcription assay, both TFB1 and TFB2 increase activity with increasing temperature, up to about 80C, and TFB1 has stronger activity in all temperatures and promoters. However, the rate of increase of TFB2 activity with increasing temperatures is greater than the rate for TFB1 in heat-shock promoters (PF0687 and Pf1616), compared to temperature-independent promoter (Pf1602) With Transcription Factor E (TFE) stabilizing the transcription preinitiation complex, transcription activities of TFB1 and TFB2 are enhanced, with TFB1 activity still stronger than TFB2 activity with all temperatures and promoters. TFE strongly enhances the activities of TFB2 in low temperatures, and makes the increasing rates of TFB1 and TFB2 become more similar in all promoters. These results indicate that TFB2 actives on heat-shock promoter, and TFE enhances TFB1 and TFB2's transcription activities and makes TFB2 acts more like TFB1. Close

• 32. [Article] Laurance Lake Temperature Model

  Laurance Lake is a reservoir located in Hood River County, Oregon (Figure 1). It is located at the base on Mt. Hood in Oregon (see Figure 2 and Figure 3), discharges into the Middle Fork of the Hood River. ...

  Citation × Citation Citation Abstract Copy Title: Laurance Lake Temperature Model Author: Berger, Chris, Wells, Scott A., Annear, Robert Leslie Year: 2005 Laurance Lake is a reservoir located in Hood River County, Oregon (Figure 1). It is located at the base on Mt. Hood in Oregon (see Figure 2 and Figure 3), discharges into the Middle Fork of the Hood River. The reservoir was constructed in 1968 for irrigation storage and has a capacity 3564 acre- feet at full pool. Since the river vio lates temperature standards, this study has been designed to construct a hydrodynamic and temperature model of Laurance reservoir in order to assess strategies for improving temperatures in the Middle Fork River. The objectives of the study are then to Develop a hydrodynamic and temperature model of Laurance Lake Calibrate the model to field data collected from November 2002 through Spring 2004 Use the model to evaluate strategies for temperature improvement through operational or structural changes to Lake Laurance The model chosen for development was CE-QUAL-W2 Version 3.2 (Cole and Wells, 2004). This is a two-dimensional unsteady hydrodynamic, temperature and water quality model that includes typical eutrophication parameters (algae, nutrients, temperature, organic matter, dissolved oxygen, pH). PSU, under the support of the Corps of Engineers Waterways Experiment Station, is a center for development of this modeling tool. Title: Laurance Lake Temperature Model Author: Berger, Chris, Wells, Scott A., Annear, Robert Leslie Year: 2005 Laurance Lake is a reservoir located in Hood River County, Oregon (Figure 1). It is located at the base on Mt. Hood in Oregon (see Figure 2 and Figure 3), discharges into the Middle Fork of the Hood River. The reservoir was constructed in 1968 for irrigation storage and has a capacity 3564 acre- feet at full pool. Since the river vio lates temperature standards, this study has been designed to construct a hydrodynamic and temperature model of Laurance reservoir in order to assess strategies for improving temperatures in the Middle Fork River. The objectives of the study are then to Develop a hydrodynamic and temperature model of Laurance Lake Calibrate the model to field data collected from November 2002 through Spring 2004 Use the model to evaluate strategies for temperature improvement through operational or structural changes to Lake Laurance The model chosen for development was CE-QUAL-W2 Version 3.2 (Cole and Wells, 2004). This is a two-dimensional unsteady hydrodynamic, temperature and water quality model that includes typical eutrophication parameters (algae, nutrients, temperature, organic matter, dissolved oxygen, pH). PSU, under the support of the Corps of Engineers Waterways Experiment Station, is a center for development of this modeling tool. Close

• 33. [Article] Effects of Tide Gate Replacement on Water Temperature ina Freshwater Slough in the Columbia River Estuary

  Dramatic declines in salmon populations in the Pacific Northwest have brought new attention to the importance of estuarine rearing habitats. Levees and tide gates used to convert estuarine wetlands into ...

  Citation × Citation Citation Abstract Copy Title: Effects of Tide Gate Replacement on Water Temperature ina Freshwater Slough in the Columbia River Estuary Author: Ennis, Sara Year: 2009 Dramatic declines in salmon populations in the Pacific Northwest have brought new attention to the importance of estuarine rearing habitats. Levees and tide gates used to convert estuarine wetlands into farmland have reduced available habitat by more than half of historical levels. Recent efforts to restore estuarine habitats include tide gate replacement, though this method has been poorly studied. As a key indicator of salmon habitat suitability, temperature was used to evaluate the effects of tide gate replacement in a tidally influenced freshwater slough in the Lower Columbia River estuary. Three tide gates in the largest slough on Tenasillahe Island were replaced in 2007 with side-hinged aluminum gates. As managed during the data collection periods, the new tide gates did not allow tidal inflow into the slough. The study employed a Before-After, Control-Impact (BACI) approach, collecting data seasonally two years before and after replacement at the impact site and at the control site, a relatively unaltered slough on nearby Welch Island. Randomized Intervention Analysis and Monte Carlo tests revealed no significant difference in slough water temperatures after tide gate replacement, although minimum temperatures dropped up and downstream of the tide gates. Although the new tide gates did not have a significant effect on water temperature, the lower minimum temperatures may have been caused by a slight increase in tidal circulation. This result suggests that slough temperatures would decrease if the tide gates were managed to increase tidal inflow, and thus improve the quality of salmon rearing habitat. Title: Effects of Tide Gate Replacement on Water Temperature ina Freshwater Slough in the Columbia River Estuary Author: Ennis, Sara Year: 2009 Dramatic declines in salmon populations in the Pacific Northwest have brought new attention to the importance of estuarine rearing habitats. Levees and tide gates used to convert estuarine wetlands into farmland have reduced available habitat by more than half of historical levels. Recent efforts to restore estuarine habitats include tide gate replacement, though this method has been poorly studied. As a key indicator of salmon habitat suitability, temperature was used to evaluate the effects of tide gate replacement in a tidally influenced freshwater slough in the Lower Columbia River estuary. Three tide gates in the largest slough on Tenasillahe Island were replaced in 2007 with side-hinged aluminum gates. As managed during the data collection periods, the new tide gates did not allow tidal inflow into the slough. The study employed a Before-After, Control-Impact (BACI) approach, collecting data seasonally two years before and after replacement at the impact site and at the control site, a relatively unaltered slough on nearby Welch Island. Randomized Intervention Analysis and Monte Carlo tests revealed no significant difference in slough water temperatures after tide gate replacement, although minimum temperatures dropped up and downstream of the tide gates. Although the new tide gates did not have a significant effect on water temperature, the lower minimum temperatures may have been caused by a slight increase in tidal circulation. This result suggests that slough temperatures would decrease if the tide gates were managed to increase tidal inflow, and thus improve the quality of salmon rearing habitat. Close

• 34. [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

• 35. [Article] Febrile response and activity in the crayfish, Pacifasticus leniusculus trowbridgii

  Poikilothermic and endothermic animals demonstrate febrile response to infection with bacteria or to injection with endogenous pyrogen extract of Prostaglandin E1. Febrile response is measured in endotherms ...

  Citation × Citation Citation Abstract Copy Title: Febrile response and activity in the crayfish, Pacifasticus leniusculus trowbridgii Author: Fletcher, Kenneth A. Year: 1988 Poikilothermic and endothermic animals demonstrate febrile response to infection with bacteria or to injection with endogenous pyrogen extract of Prostaglandin E1. Febrile response is measured in endotherms as a relative change in metabolically achieved body temperature and in poikilotherms as an increase in selected temperatures relative to previously established preferred temperatures. Final preferendum change with environmental factors or associated physiological states. Title: Febrile response and activity in the crayfish, Pacifasticus leniusculus trowbridgii Author: Fletcher, Kenneth A. Year: 1988 Poikilothermic and endothermic animals demonstrate febrile response to infection with bacteria or to injection with endogenous pyrogen extract of Prostaglandin E1. Febrile response is measured in endotherms as a relative change in metabolically achieved body temperature and in poikilotherms as an increase in selected temperatures relative to previously established preferred temperatures. Final preferendum change with environmental factors or associated physiological states. Close

• 36. [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

• 37. [Article] The metabolic cost of behavioral thermoregulation of body temperature in the northern alligator lizard Gerrhonotus coeruleus, and how it affects the classical concept of eurythermality

  The effect of total metabolic cost expenditures on the precision of behavioral thermoregulation was investigated for the purportedly eurythermic Northern Alligator lizard (Gerrhonotus coeruleus). An operant ...

  Citation × Citation Citation Abstract Copy Title: The metabolic cost of behavioral thermoregulation of body temperature in the northern alligator lizard Gerrhonotus coeruleus, and how it affects the classical concept of eurythermality Author: Campbell, James Dudley Year: 1981 The effect of total metabolic cost expenditures on the precision of behavioral thermoregulation was investigated for the purportedly eurythermic Northern Alligator lizard (Gerrhonotus coeruleus). An operant apparatus was designed to test metabolic output at different heat reinforcement magnitudes. The mean TB reflected in each trial was positively correlated to the length of reinforcement. The shuttle rate during each trial was inversely correlated to the length of reinforcement. The standard deviation and total metabolic costs did not vary significantly between trials undertaken at the same ambient temperature. Eurythermality in G. coeruleus is caused by fluctuations in preferred body temperature and not by fluctuations around this temperature. The metabolic cost of behavioral thermoregulation did not change with corresponding changes in reinforcement magnitude. This indicates that eurythermality is the recorded effect of lizards behaviorally regulating to different TB in a stenothermic manner, rather than of random TB fluctuations in a wide range of normal activity (the classical view of eurythermality). Title: The metabolic cost of behavioral thermoregulation of body temperature in the northern alligator lizard Gerrhonotus coeruleus, and how it affects the classical concept of eurythermality Author: Campbell, James Dudley Year: 1981 The effect of total metabolic cost expenditures on the precision of behavioral thermoregulation was investigated for the purportedly eurythermic Northern Alligator lizard (Gerrhonotus coeruleus). An operant apparatus was designed to test metabolic output at different heat reinforcement magnitudes. The mean TB reflected in each trial was positively correlated to the length of reinforcement. The shuttle rate during each trial was inversely correlated to the length of reinforcement. The standard deviation and total metabolic costs did not vary significantly between trials undertaken at the same ambient temperature. Eurythermality in G. coeruleus is caused by fluctuations in preferred body temperature and not by fluctuations around this temperature. The metabolic cost of behavioral thermoregulation did not change with corresponding changes in reinforcement magnitude. This indicates that eurythermality is the recorded effect of lizards behaviorally regulating to different TB in a stenothermic manner, rather than of random TB fluctuations in a wide range of normal activity (the classical view of eurythermality). Close

• 38. [Article] The Role of Temperature in Testing Deep Submicron CMOS ASICs

  Among the many efforts to improve the IC test process are tests that attempt to differentiate between healthy and defective or low reliability ICs by manipulating the operating conditions of the IC being ...

  Citation × Citation Citation Abstract Copy Title: The Role of Temperature in Testing Deep Submicron CMOS ASICs Author: Long, Ethan Schuyler Year: 2003 Among the many efforts to improve the IC test process are tests that attempt to differentiate between healthy and defective or low reliability ICs by manipulating the operating conditions of the IC being tested. This thesis attempts to improve the common understanding of multiple and targeted temperature testing by evaluating work published on the subject to date and by presenting previously unpublished empirical observations. The empirical observations are made from SCAN and LBIST based MinVDD measurements, Static IDD measurements, as well as parametric measurements of transistor characteristics. The test vehicles used are 0.25μm and 0.18μm CMOS ASICs fabricated by LSI Logic. An IC’s performance is bound by a three dimensional space defined by VDD, frequency, and temperature. A model is presented to explain the boundaries of the performance region in terms of the ability of the IC’s constituent transistors to provide power and the Zero-Temperature-Coefficient (ZTC). Also, it is determined that multiple temperature testing can add new tests to current test suites to improve the resolution between healthy and defective ICs. Title: The Role of Temperature in Testing Deep Submicron CMOS ASICs Author: Long, Ethan Schuyler Year: 2003 Among the many efforts to improve the IC test process are tests that attempt to differentiate between healthy and defective or low reliability ICs by manipulating the operating conditions of the IC being tested. This thesis attempts to improve the common understanding of multiple and targeted temperature testing by evaluating work published on the subject to date and by presenting previously unpublished empirical observations. The empirical observations are made from SCAN and LBIST based MinVDD measurements, Static IDD measurements, as well as parametric measurements of transistor characteristics. The test vehicles used are 0.25μm and 0.18μm CMOS ASICs fabricated by LSI Logic. An IC’s performance is bound by a three dimensional space defined by VDD, frequency, and temperature. A model is presented to explain the boundaries of the performance region in terms of the ability of the IC’s constituent transistors to provide power and the Zero-Temperature-Coefficient (ZTC). Also, it is determined that multiple temperature testing can add new tests to current test suites to improve the resolution between healthy and defective ICs. Close

• 39. [Article] Classifying Reanalysis Surface Temperature Probability Density Functions (PDFs) over North America with Cluster Analysis

  An important step in projecting future climate change impacts on extremes involves quantifying the underlying probability distribution functions (PDFs) of climate variables. However, doing so can prove ...

  Citation × Citation Citation Abstract Copy Title: Classifying Reanalysis Surface Temperature Probability Density Functions (PDFs) over North America with Cluster Analysis Author: Loikith, Paul C., Lintner, Benjamin R., Kim, Jinwon, Lee, Huikyo Year: 2013 An important step in projecting future climate change impacts on extremes involves quantifying the underlying probability distribution functions (PDFs) of climate variables. However, doing so can prove challenging when multiple models and large domains are considered. Here an approach to PDF quantification using k-means clustering is considered. A standard clustering algorithm (with k = 5 clusters) is applied to 33 years of daily January surface temperature from two state-of-the-art reanalysis products, the North American Regional Reanalysis and the Modern Era Retrospective Analysis for Research and Applications. The resulting cluster assignments yield spatially coherent patterns that can be broadly related to distinct climate regimes over North America, e.g., low variability over the tropical oceans or temperature advection across stronger or weaker gradients. This technique has the potential to be a useful and intuitive tool for evaluation of model-simulated PDF structure and could provide insight into projections of future changes in temperature. Title: Classifying Reanalysis Surface Temperature Probability Density Functions (PDFs) over North America with Cluster Analysis Author: Loikith, Paul C., Lintner, Benjamin R., Kim, Jinwon, Lee, Huikyo Year: 2013 An important step in projecting future climate change impacts on extremes involves quantifying the underlying probability distribution functions (PDFs) of climate variables. However, doing so can prove challenging when multiple models and large domains are considered. Here an approach to PDF quantification using k-means clustering is considered. A standard clustering algorithm (with k = 5 clusters) is applied to 33 years of daily January surface temperature from two state-of-the-art reanalysis products, the North American Regional Reanalysis and the Modern Era Retrospective Analysis for Research and Applications. The resulting cluster assignments yield spatially coherent patterns that can be broadly related to distinct climate regimes over North America, e.g., low variability over the tropical oceans or temperature advection across stronger or weaker gradients. This technique has the potential to be a useful and intuitive tool for evaluation of model-simulated PDF structure and could provide insight into projections of future changes in temperature. Close

• 40. [Article] The surface plasmon enhancement effect on adsorbed molecules at elevated temperatures

  The surface plasmon enhancement effect on adsorbed molecules at elevated substrate temperatures is studied theoretically using surface enhanced Raman scattering (SERS) as an example. The surface structure ...

  Citation × Citation Citation Abstract Copy Title: The surface plasmon enhancement effect on adsorbed molecules at elevated temperatures Author: Leung, P.T., Chiang, Hai-Pang, Tse, W. S. Year: 1998 The surface plasmon enhancement effect on adsorbed molecules at elevated substrate temperatures is studied theoretically using surface enhanced Raman scattering (SERS) as an example. The surface structure is idealized to be a monodisperse spherical particle with its nonlocal dielectric response accounted for. The temperature effects are modeled using a temperature-dependent collision frequency in the Drude model. Numerical results show that only a small decrease in the SERS enhancement ratio occurs for temperatures up to the melting point of the substrate, even for scattering close to the surface plasmon resonance frequency of the metal. More definitive results are subjected to more realistic modeling as well as systematic experimental studies. The implication of this result to other surface photochemical processes is discussed. Title: The surface plasmon enhancement effect on adsorbed molecules at elevated temperatures Author: Leung, P.T., Chiang, Hai-Pang, Tse, W. S. Year: 1998 The surface plasmon enhancement effect on adsorbed molecules at elevated substrate temperatures is studied theoretically using surface enhanced Raman scattering (SERS) as an example. The surface structure is idealized to be a monodisperse spherical particle with its nonlocal dielectric response accounted for. The temperature effects are modeled using a temperature-dependent collision frequency in the Drude model. Numerical results show that only a small decrease in the SERS enhancement ratio occurs for temperatures up to the melting point of the substrate, even for scattering close to the surface plasmon resonance frequency of the metal. More definitive results are subjected to more realistic modeling as well as systematic experimental studies. The implication of this result to other surface photochemical processes is discussed. Close

• 41. [Article] Meyer-Neldel rule for dark current in charge-coupled devices

  We present the results of a systematic study of the dark current in each pixel of a charged-coupled device chip. It was found that the Arrhenius plot, at temperatures between 222 and 291 K, deviated from ...

  Citation × Citation Citation Abstract Copy Title: Meyer-Neldel rule for dark current in charge-coupled devices Author: Widenhorn, Ralf, Mündermann, Lars, Rest, Armin, Bodegom, Erik Year: 2001 We present the results of a systematic study of the dark current in each pixel of a charged-coupled device chip. It was found that the Arrhenius plot, at temperatures between 222 and 291 K, deviated from a linear behavior in the form of continuous bending. However, as a first approximation, the dark current, D, can be expressed as: D=Dₒ exp(−ΔE/kT),where ΔE is the activation energy, k is Boltzmann’s constant, and T the absolute temperature. It was found that ΔE and the exponential prefactor Dₒ follow the Meyer–Neldel rule (MNR) for all of the more than 222,000 investigated pixels. The isokinetic temperature, Tₒ, for the process was found as 294 K. However, measurements at 313 K did not show the predicted inversion in the dark current. It was found that the dark current for different pixels merged at temperatures higher than Tₒ. A model is presented which explains the nonlinearity and the merging of the dark current for different pixels with increasing temperature. Possible implications of this finding regarding the MNR are discussed. Title: Meyer-Neldel rule for dark current in charge-coupled devices Author: Widenhorn, Ralf, Mündermann, Lars, Rest, Armin, Bodegom, Erik Year: 2001 We present the results of a systematic study of the dark current in each pixel of a charged-coupled device chip. It was found that the Arrhenius plot, at temperatures between 222 and 291 K, deviated from a linear behavior in the form of continuous bending. However, as a first approximation, the dark current, D, can be expressed as: D=Dₒ exp(−ΔE/kT),where ΔE is the activation energy, k is Boltzmann’s constant, and T the absolute temperature. It was found that ΔE and the exponential prefactor Dₒ follow the Meyer–Neldel rule (MNR) for all of the more than 222,000 investigated pixels. The isokinetic temperature, Tₒ, for the process was found as 294 K. However, measurements at 313 K did not show the predicted inversion in the dark current. It was found that the dark current for different pixels merged at temperatures higher than Tₒ. A model is presented which explains the nonlinearity and the merging of the dark current for different pixels with increasing temperature. Possible implications of this finding regarding the MNR are discussed. Close

• 42. [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

• 43. [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

• 44. [Article] Mechanisms of Methane Transport Through Trees

  Although the dynamics of methane (CH4) emission from croplands and wetlands have been fairly well investigated, the contribution of trees to global methane emission and the mechanisms of tree transport ...

  Citation × Citation Citation Abstract Copy Title: Mechanisms of Methane Transport Through Trees Author: Kutschera, Ellynne Marie Year: 2013 Although the dynamics of methane (CH4) emission from croplands and wetlands have been fairly well investigated, the contribution of trees to global methane emission and the mechanisms of tree transport are relatively unknown. Methane emissions from the common wetland tree species Populus trichocarpa (black cottonwood) native to the Pacific Northwest were measured under hydroponic conditions in order to separate plant transport mechanisms from the influence of soil processes. Roots were exposed to methane enriched water and canopy emissions of methane were measured using a canopy enclosure. Methane accumulation in the canopy was generally linear and the average canopy methane flux was 3.0 ± 2.6 μg CH4 min-1. Flux magnitudes from stem experiments scaled to the area of the main tree stem are comparable to whole-canopy flux values, indicating that the majority of methane emitted from the tree leaves through the stem. Samples for stable carbon isotope composition were taken during the canopy experiments. Compared to the isotopic composition of root water methane, canopy methane was depleted in 13C on average by 8.6 ± 3.3 permil; this indicates that methane moving through the tree is not following a purely bulk flow pathway (where no depletion would occur), but is instead subject to at least one fractionating mechanism. When temperature was varied, the flux at the coolest temperature was significantly different from the higher flux at the warmest temperature (p-value less than 0.02). The calculated Q10 for methane flux was 2.4, which indicates a positive feedback with temperature increase. Analysis of δ13C values of emitted CH4 in the temperature experiments shows increasing depletion with cooler temperatures and lower flux. This indicates that not only does the magnitude of flux vary with temperature, but the actual dominant transport mechanism changes as well. Title: Mechanisms of Methane Transport Through Trees Author: Kutschera, Ellynne Marie Year: 2013 Although the dynamics of methane (CH4) emission from croplands and wetlands have been fairly well investigated, the contribution of trees to global methane emission and the mechanisms of tree transport are relatively unknown. Methane emissions from the common wetland tree species Populus trichocarpa (black cottonwood) native to the Pacific Northwest were measured under hydroponic conditions in order to separate plant transport mechanisms from the influence of soil processes. Roots were exposed to methane enriched water and canopy emissions of methane were measured using a canopy enclosure. Methane accumulation in the canopy was generally linear and the average canopy methane flux was 3.0 ± 2.6 μg CH4 min-1. Flux magnitudes from stem experiments scaled to the area of the main tree stem are comparable to whole-canopy flux values, indicating that the majority of methane emitted from the tree leaves through the stem. Samples for stable carbon isotope composition were taken during the canopy experiments. Compared to the isotopic composition of root water methane, canopy methane was depleted in 13C on average by 8.6 ± 3.3 permil; this indicates that methane moving through the tree is not following a purely bulk flow pathway (where no depletion would occur), but is instead subject to at least one fractionating mechanism. When temperature was varied, the flux at the coolest temperature was significantly different from the higher flux at the warmest temperature (p-value less than 0.02). The calculated Q10 for methane flux was 2.4, which indicates a positive feedback with temperature increase. Analysis of δ13C values of emitted CH4 in the temperature experiments shows increasing depletion with cooler temperatures and lower flux. This indicates that not only does the magnitude of flux vary with temperature, but the actual dominant transport mechanism changes as well. Close

• 45. [Article] Feedbacks of Methane and Nitrous Oxide Emissions from Rice Agriculture

  The effect of global warming on methane (CH₄) and nitrous oxide (N₂O) emissions from agriculture was investigated and simulated from a soil warming experiment. Experiments were designed and installed in ...

  Citation × Citation Citation Abstract Copy Title: Feedbacks of Methane and Nitrous Oxide Emissions from Rice Agriculture Author: Sithole, Alec Year: 2011 The effect of global warming on methane (CH₄) and nitrous oxide (N₂O) emissions from agriculture was investigated and simulated from a soil warming experiment. Experiments were designed and installed in a temperature controlled greenhouse. The relationships between elevated temperatures and CH₄ and N₂O emissions were determined and calculated as the Q₁₀s of production, emission and oxidation. A study of the populations of methanogens and methanotrophs at a range of soil temperatures was performed based on soil molecular DNA analysis. This study showed that global warming would increase CH₄ emissions from rice agriculture and that the resultant emissions will be potentially large enough to cause changes in the present atmospheric concentrations. This research also showed that this increase was most evident for soil temperatures below 30⁰C, above which emissions decreased with increasing temperature. The seasonal average Q₁₀s of CH₄ emission, production, oxidation, methanogen and methanotroph populations were found to be 1.7, 2.6 and 2.2, 2.6 and 3.8, respectively, over a temperature of 20-32⁰C. Considering that the processes of CH₄ production and emission are similar to those in natural wetlands, which is the largest source of atmospheric CH₄, the contribution of this feedback is likely to cause a significant increase to the present CH₄ atmospheric budget if the current global warming trend persists over the next century. The Q₁₀s of N₂O emissions and production were 0.5-3.3 and 0.4-2.9, respectively. The low Q₁₀ values found for N₂O suggest that although global warming will have a direct impact on the production and emission rates. Nevertheless, the magnitude of the impact of global on both CH₄ and N₂O emissions from agriculture is likely to vary from one region to another due to the spatial variations in agricultural soil temperatures and the likely changes in the global regional distribution of water resources (water tables, rainfall patterns), water management practices and the responses of terrestrial CH₄ and N₂O sources such as natural wetlands and plants. Title: Feedbacks of Methane and Nitrous Oxide Emissions from Rice Agriculture Author: Sithole, Alec Year: 2011 The effect of global warming on methane (CH₄) and nitrous oxide (N₂O) emissions from agriculture was investigated and simulated from a soil warming experiment. Experiments were designed and installed in a temperature controlled greenhouse. The relationships between elevated temperatures and CH₄ and N₂O emissions were determined and calculated as the Q₁₀s of production, emission and oxidation. A study of the populations of methanogens and methanotrophs at a range of soil temperatures was performed based on soil molecular DNA analysis. This study showed that global warming would increase CH₄ emissions from rice agriculture and that the resultant emissions will be potentially large enough to cause changes in the present atmospheric concentrations. This research also showed that this increase was most evident for soil temperatures below 30⁰C, above which emissions decreased with increasing temperature. The seasonal average Q₁₀s of CH₄ emission, production, oxidation, methanogen and methanotroph populations were found to be 1.7, 2.6 and 2.2, 2.6 and 3.8, respectively, over a temperature of 20-32⁰C. Considering that the processes of CH₄ production and emission are similar to those in natural wetlands, which is the largest source of atmospheric CH₄, the contribution of this feedback is likely to cause a significant increase to the present CH₄ atmospheric budget if the current global warming trend persists over the next century. The Q₁₀s of N₂O emissions and production were 0.5-3.3 and 0.4-2.9, respectively. The low Q₁₀ values found for N₂O suggest that although global warming will have a direct impact on the production and emission rates. Nevertheless, the magnitude of the impact of global on both CH₄ and N₂O emissions from agriculture is likely to vary from one region to another due to the spatial variations in agricultural soil temperatures and the likely changes in the global regional distribution of water resources (water tables, rainfall patterns), water management practices and the responses of terrestrial CH₄ and N₂O sources such as natural wetlands and plants. Close

• 46. [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

• 47. [Article] Effects of Climate Change on Water Quality in the Yaquina Estuary, Oregon

  As part of a larger study to examine the effect of climate change (CC) on estuarine resources, we simulated the effect of rising sea level, alterations in river discharge, and increasing atmospheric temperatures ...

  Citation × Citation Citation Abstract Copy Title: Effects of Climate Change on Water Quality in the Yaquina Estuary, Oregon Author: Brown, Cheryl A., Sharp, Darrin, Chang, Heejun, Steele, Madeline Year: 2011 As part of a larger study to examine the effect of climate change (CC) on estuarine resources, we simulated the effect of rising sea level, alterations in river discharge, and increasing atmospheric temperatures on water quality in the Yaquina Estuary. Due to uncertainty in the effects of climate change, initial model simulations were performed for different steady river discharge rates that span the historical range in inflow, and for a range of increases in sea level and atmospheric temperature. Model simulations suggest that in the central portion of the estuary (19 km from mouth), a 60-cm increase in sea level will result in a 2-3 psu change in salinity across a broad range of river discharges. For the oligohaline portion of the estuary, salinity increases associated with a rise in sea level of 60 cm are only apparent at low river discharge rates (< 50 m3 s-1). Simulations suggest that the water temperatures near the mouth of the estuary will decrease due to rising sea level, while water temperatures in upriver portions of the estuary will increase due to rising atmospheric temperatures. We present results which demonstrate how the interaction of changes in river discharge, rising sea level, and atmospheric temperature associated with climate change produce non-linear patterns in the response of estuarine salinity and temperature, which vary with location inside the estuary and season. We also will discuss the importance of presenting results in a manner that incorporates uncertainty in climate projections. Title: Effects of Climate Change on Water Quality in the Yaquina Estuary, Oregon Author: Brown, Cheryl A., Sharp, Darrin, Chang, Heejun, Steele, Madeline Year: 2011 As part of a larger study to examine the effect of climate change (CC) on estuarine resources, we simulated the effect of rising sea level, alterations in river discharge, and increasing atmospheric temperatures on water quality in the Yaquina Estuary. Due to uncertainty in the effects of climate change, initial model simulations were performed for different steady river discharge rates that span the historical range in inflow, and for a range of increases in sea level and atmospheric temperature. Model simulations suggest that in the central portion of the estuary (19 km from mouth), a 60-cm increase in sea level will result in a 2-3 psu change in salinity across a broad range of river discharges. For the oligohaline portion of the estuary, salinity increases associated with a rise in sea level of 60 cm are only apparent at low river discharge rates (< 50 m3 s-1). Simulations suggest that the water temperatures near the mouth of the estuary will decrease due to rising sea level, while water temperatures in upriver portions of the estuary will increase due to rising atmospheric temperatures. We present results which demonstrate how the interaction of changes in river discharge, rising sea level, and atmospheric temperature associated with climate change produce non-linear patterns in the response of estuarine salinity and temperature, which vary with location inside the estuary and season. We also will discuss the importance of presenting results in a manner that incorporates uncertainty in climate projections. Close

• 48. [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

• 49. [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

• 50. [Article] Valley Floor Climate Observations from the McMurdo Dry Valleys, Antarctica, 1986-2000

  Climate observations from the McMurdo dry valleys, East Antarctica are presented from a network of seven valley floor automatic meteorological stations during the period 1986 to 2000. Mean annual temperatures ...

  Citation × Citation Citation Abstract Copy Title: Valley Floor Climate Observations from the McMurdo Dry Valleys, Antarctica, 1986-2000 Author: Doran, Peter T., McKay, Christopher P., Clow, Gary D., Dana, Gayle L., Fountain, Andrew G., Nylen, Thomas H., Lyons, W. Berry Year: 2002 Climate observations from the McMurdo dry valleys, East Antarctica are presented from a network of seven valley floor automatic meteorological stations during the period 1986 to 2000. Mean annual temperatures ranged from −14.8°C to −30.0°C, depending on the site and period of measurement. Mean annual relative humidity is generally highest near the coast. Mean annual wind speed increases with proximity to the polar plateau. Site to site variation in mean annual solar flux and PAR is due to exposure of each station and changes over time are likely related to changes in cloudiness. During the non-summer months, strong katabatic winds are frequent at some sites and infrequent at others, creating large variation in mean annual temperature owing to the warming effect of the winds. Katabatic wind exposure appears to be controlled to a large degree by the presence of colder air in the region that collects at low points and keeps the warm less dense katabatic flow from the ground. The strong influence of katabatic winds makes prediction of relative mean annual temperature based on geographical position (elevation and distance from the coast) alone, not possible. During the summer months, onshore winds dominate and warm as they progress through the valleys creating a strong linear relationship (r² = 0.992) of increasing potential temperature with distance from the coast (0.09°C km⁻¹). In contrast to mean annual temperature, summer temperature lends itself quite well to model predictions, and is used to construct a statistical model for predicting summer dry valley temperatures at unmonitored sites. Title: Valley Floor Climate Observations from the McMurdo Dry Valleys, Antarctica, 1986-2000 Author: Doran, Peter T., McKay, Christopher P., Clow, Gary D., Dana, Gayle L., Fountain, Andrew G., Nylen, Thomas H., Lyons, W. Berry Year: 2002 Climate observations from the McMurdo dry valleys, East Antarctica are presented from a network of seven valley floor automatic meteorological stations during the period 1986 to 2000. Mean annual temperatures ranged from −14.8°C to −30.0°C, depending on the site and period of measurement. Mean annual relative humidity is generally highest near the coast. Mean annual wind speed increases with proximity to the polar plateau. Site to site variation in mean annual solar flux and PAR is due to exposure of each station and changes over time are likely related to changes in cloudiness. During the non-summer months, strong katabatic winds are frequent at some sites and infrequent at others, creating large variation in mean annual temperature owing to the warming effect of the winds. Katabatic wind exposure appears to be controlled to a large degree by the presence of colder air in the region that collects at low points and keeps the warm less dense katabatic flow from the ground. The strong influence of katabatic winds makes prediction of relative mean annual temperature based on geographical position (elevation and distance from the coast) alone, not possible. During the summer months, onshore winds dominate and warm as they progress through the valleys creating a strong linear relationship (r² = 0.992) of increasing potential temperature with distance from the coast (0.09°C km⁻¹). In contrast to mean annual temperature, summer temperature lends itself quite well to model predictions, and is used to construct a statistical model for predicting summer dry valley temperatures at unmonitored sites. Close