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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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