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• 41. [Article] Surface temperature effects on the fouling characteristics of cooling water

  A cooling tower system was built and fouling resistances were studied for cooling water flowing over a heated tubular surface. The cooling water studied was formulated in an effort to match industrial cooling ...

  Citation × Citation Citation Abstract Copy Title: Surface temperature effects on the fouling characteristics of cooling water Author: Story, Michael Kenneth A cooling tower system was built and fouling resistances were studied for cooling water flowing over a heated tubular surface. The cooling water studied was formulated in an effort to match industrial cooling water quality. The water used in this study had an average Ryznar Stability Index of 6.23 and was formulated by adding calcium chloride and magnesium carbonate to tap water. Fouling resistance versus time was plotted for each experimental run, and the resulting curves indicate a close approximation to industrial conditions can be made in a laboratory environment. Fouling resistances were obtained at surface temperatures from 136°F to 199°F. The flow velocity and water quality were held constant during these runs. A correlation modeled after the Arrhenius temperature function was developed for surface temperature and asymptotic fouling resistance values. The model obtained has a correlation coefficient of .95 and a standard deviation of 4. 08% for data obtained in this study. The Ryznar Stability Index proved to be a poor indicator of water fouling tendency with the cooling water used in the present study. Title: Surface temperature effects on the fouling characteristics of cooling water Author: Story, Michael Kenneth A cooling tower system was built and fouling resistances were studied for cooling water flowing over a heated tubular surface. The cooling water studied was formulated in an effort to match industrial cooling water quality. The water used in this study had an average Ryznar Stability Index of 6.23 and was formulated by adding calcium chloride and magnesium carbonate to tap water. Fouling resistance versus time was plotted for each experimental run, and the resulting curves indicate a close approximation to industrial conditions can be made in a laboratory environment. Fouling resistances were obtained at surface temperatures from 136°F to 199°F. The flow velocity and water quality were held constant during these runs. A correlation modeled after the Arrhenius temperature function was developed for surface temperature and asymptotic fouling resistance values. The model obtained has a correlation coefficient of .95 and a standard deviation of 4. 08% for data obtained in this study. The Ryznar Stability Index proved to be a poor indicator of water fouling tendency with the cooling water used in the present study. Close

• 42. [Article] Design and testing of intrustive conductivity probes for the measurement of two-phase flow parameters

  This thesis examines two techniques for measuring two-phase flow parameters in an air/water system using intrusive conductivity probes. Specifically, the theoretical derivation for measuring void fraction ...

  Citation × Citation Citation Abstract Copy Title: Design and testing of intrustive conductivity probes for the measurement of two-phase flow parameters Author: McCreary, David M. This thesis examines two techniques for measuring two-phase flow parameters in an air/water system using intrusive conductivity probes. Specifically, the theoretical derivation for measuring void fraction and interfacial area using a two-sensor needle-type probe is derived, and a statistical analysis of the accuracy using the two-sensor probe for measuring interfacial area will be determined from a comprehensive literature review. The second technique used to measure void fraction in air/water flows is with a half-ring type conductivity probe. This half-ring type probe measures an area-averaged void fraction, while the needle-type probe measures local two-phase parameters. A single-sensor needle-type probe is used to experimentally measure void fraction in a test section, and is then benchmarked with another instrument as well as the drift-flux model. The half-ring type probe is then cross-calibrated with the needle-type probe. A complete system for measurement of local void fraction in an air/water two-phase mixture using two measurement techniques is presented. A detailed design procedure for a single-sensor conductivity probe as well as a half-ring type probe, and the corresponding circuits to power them are discussed. The two techniques discussed are accurate, simple, reliable, and inexpensive. Title: Design and testing of intrustive conductivity probes for the measurement of two-phase flow parameters Author: McCreary, David M. This thesis examines two techniques for measuring two-phase flow parameters in an air/water system using intrusive conductivity probes. Specifically, the theoretical derivation for measuring void fraction and interfacial area using a two-sensor needle-type probe is derived, and a statistical analysis of the accuracy using the two-sensor probe for measuring interfacial area will be determined from a comprehensive literature review. The second technique used to measure void fraction in air/water flows is with a half-ring type conductivity probe. This half-ring type probe measures an area-averaged void fraction, while the needle-type probe measures local two-phase parameters. A single-sensor needle-type probe is used to experimentally measure void fraction in a test section, and is then benchmarked with another instrument as well as the drift-flux model. The half-ring type probe is then cross-calibrated with the needle-type probe. A complete system for measurement of local void fraction in an air/water two-phase mixture using two measurement techniques is presented. A detailed design procedure for a single-sensor conductivity probe as well as a half-ring type probe, and the corresponding circuits to power them are discussed. The two techniques discussed are accurate, simple, reliable, and inexpensive. Close

• 43. [Article] Estuaries in Motion: Teaching Estuarine Flow Concepts through Video

  A video explaining estuarine flow concepts was produced for a target audience of high school students in physics and earth science classes. This honors thesis explains the video production and concepts ...

  Citation × Citation Citation Abstract Copy Title: Estuaries in Motion: Teaching Estuarine Flow Concepts through Video Author: Cameron, Marina R. A video explaining estuarine flow concepts was produced for a target audience of high school students in physics and earth science classes. This honors thesis explains the video production and concepts introduced in the video. Title: Estuaries in Motion: Teaching Estuarine Flow Concepts through Video Author: Cameron, Marina R. A video explaining estuarine flow concepts was produced for a target audience of high school students in physics and earth science classes. This honors thesis explains the video production and concepts introduced in the video. Close

• 44. [Article] Interactions between microbial dynamics, water flow, and solute transport in unsaturated porous media

  Bioremediation in the vadose zone is unpredictable because of poor understanding of factors influencing microbial growth in this environment. A lab-scale experimental system was developed to examine, noninvasively, interactions ...

  Citation × Citation Citation Abstract Copy Title: Interactions between microbial dynamics, water flow, and solute transport in unsaturated porous media Author: Yarwood, Rockie R. Bioremediation in the vadose zone is unpredictable because of poor understanding of factors influencing microbial growth in this environment. A lab-scale experimental system was developed to examine, noninvasively, interactions between microbial growth, water flow, and solute transport in unsaturated porous media. Measurements of microbial colonization, and its impact on hydrology, were facilitated by using the luxCDABE-containing reporter bacterium Pseudomonas fluorescens HK44 and digital CCD imaging. Experiments were conducted in glass-walled two-dimensional flow cells (45 x 50 x 1 cm) packed with silica sand. Several bioengineering problems associated with chamber design and function required solution before microbial experiments were successful. These included: choice of materials for chamber components; development of sterilization, packing, and inoculation protocols; and development of procedures for data collection and chamber maintenance during experiments lasting several days. Bacterial growth was mapped daily by quantifying development of salicylate-induced bioluminescence. A model relating the rate of increase in light emission after induction successfully predicted microbial densities over four orders of magnitude (R²=0.95) provided that sufficient oxygen for the bioluminescence reaction was available. Total model-predicted growth during a one-week experiment agreed with potential growth calculated from the mass-balance of the system and previously established kinetic parameters (predicted, 1.2x10¹² cells; calculated, 1.7x10¹² cells). Although the rate of expansion of the colonized zone (and predicted populations in newly colonized regions) remained relatively constant, the proportion of the daily potential growth remaining within the chamber declined over time. Monitoring of bioluminescence revealed the development of an (hypothesized) anaerobic zone associated with microbial growth in the unsaturated porous media. Water content and flow streams were measured using light transmission. Accumulation of microbial growth modified the hydrologic properties of the sand causing up to 50% decrease in saturation within the colonized zone, diversion of flow around the colonized zone, and lowering (5 cm) of the capillary fringe height. Apparent solute velocity through the colonized region was reduced from 0.39 cm min⁻¹ (R²=0.99) to 0.25 cm min⁻¹ (R²=0.99). These experiments provide proof-of-concept for combining light transmission and bioluminescence technologies to study interactions between microbial growth and hydrology in unsaturated porous media. Title: Interactions between microbial dynamics, water flow, and solute transport in unsaturated porous media Author: Yarwood, Rockie R. Bioremediation in the vadose zone is unpredictable because of poor understanding of factors influencing microbial growth in this environment. A lab-scale experimental system was developed to examine, noninvasively, interactions between microbial growth, water flow, and solute transport in unsaturated porous media. Measurements of microbial colonization, and its impact on hydrology, were facilitated by using the luxCDABE-containing reporter bacterium Pseudomonas fluorescens HK44 and digital CCD imaging. Experiments were conducted in glass-walled two-dimensional flow cells (45 x 50 x 1 cm) packed with silica sand. Several bioengineering problems associated with chamber design and function required solution before microbial experiments were successful. These included: choice of materials for chamber components; development of sterilization, packing, and inoculation protocols; and development of procedures for data collection and chamber maintenance during experiments lasting several days. Bacterial growth was mapped daily by quantifying development of salicylate-induced bioluminescence. A model relating the rate of increase in light emission after induction successfully predicted microbial densities over four orders of magnitude (R²=0.95) provided that sufficient oxygen for the bioluminescence reaction was available. Total model-predicted growth during a one-week experiment agreed with potential growth calculated from the mass-balance of the system and previously established kinetic parameters (predicted, 1.2x10¹² cells; calculated, 1.7x10¹² cells). Although the rate of expansion of the colonized zone (and predicted populations in newly colonized regions) remained relatively constant, the proportion of the daily potential growth remaining within the chamber declined over time. Monitoring of bioluminescence revealed the development of an (hypothesized) anaerobic zone associated with microbial growth in the unsaturated porous media. Water content and flow streams were measured using light transmission. Accumulation of microbial growth modified the hydrologic properties of the sand causing up to 50% decrease in saturation within the colonized zone, diversion of flow around the colonized zone, and lowering (5 cm) of the capillary fringe height. Apparent solute velocity through the colonized region was reduced from 0.39 cm min⁻¹ (R²=0.99) to 0.25 cm min⁻¹ (R²=0.99). These experiments provide proof-of-concept for combining light transmission and bioluminescence technologies to study interactions between microbial growth and hydrology in unsaturated porous media. Close

• 45. [Article] Documentation for a combined carbon-water flow stand level coniferous forest model

  The following report Introduces a documentation scheme for flow oriented ecosystem models and shows its application to a carbon-water model developed within the coniferous biome. This documentation scheme has ...

  Citation × Citation Citation Abstract Copy Title: Documentation for a combined carbon-water flow stand level coniferous forest model Author: Sollins, P., U.S. International Biological Program. Coniferous Forest Biome, Swartzman, G. L. (Gordon L.), University of Washington The following report Introduces a documentation scheme for flow oriented ecosystem models and shows its application to a carbon-water model developed within the coniferous biome. This documentation scheme has remained operative through revision of this model and expansion of It to include nutrient flows. This model and subsequent versions are operative simulations on the CDC 6400 at the University of Washington using SIMCOMP (Gustafson S Innis (1971)).and give reasonable output. The purpose of this report is mainly to introduce the reader to the documentation scheme which we have found so effective in maintaining a running history of the modeling process for large scale models. We hope that it will lead to the adoption of this or a similar documentation scheme as a standard for ecological modeling. Title: Documentation for a combined carbon-water flow stand level coniferous forest model Author: Sollins, P., U.S. International Biological Program. Coniferous Forest Biome, Swartzman, G. L. (Gordon L.), University of Washington The following report Introduces a documentation scheme for flow oriented ecosystem models and shows its application to a carbon-water model developed within the coniferous biome. This documentation scheme has remained operative through revision of this model and expansion of It to include nutrient flows. This model and subsequent versions are operative simulations on the CDC 6400 at the University of Washington using SIMCOMP (Gustafson S Innis (1971)).and give reasonable output. The purpose of this report is mainly to introduce the reader to the documentation scheme which we have found so effective in maintaining a running history of the modeling process for large scale models. We hope that it will lead to the adoption of this or a similar documentation scheme as a standard for ecological modeling. Close

• 46. [Article] Experimental evaluation and numerical modeling of a water source heat pump evaporator

  Water source heat pumps are increasingly being used for residential and commercial space heating. Typically, these heat pumps are capable of both heating and cooling, and historically the design emphasis has ...

  Citation × Citation Citation Abstract Copy Title: Experimental evaluation and numerical modeling of a water source heat pump evaporator Author: Means, Paul Morency Water source heat pumps are increasingly being used for residential and commercial space heating. Typically, these heat pumps are capable of both heating and cooling, and historically the design emphasis has been on improving the units' cooling performance. Recently, there has been more interest in improving the heating performance, however, in order to optimize the design for improved heating performance data on the heat pump components operating in the heating mode are required. These data have not been available for the waterto- refrigerant heat exchangers typically installed in unitary water source heat pumps. The purpose of this work is to provide performance data on such heat exchangers operating as evaporators (data is available for the heat exchangers operating as condensers) and to provide a numerical model by which a limited amount of evaporator data might be expanded for system modeling and optimization studies. A well instrumented water-to-water heat pump was assembled for the purpose of testing two such water-to-refrigerant heat exchangers to determine their heat transfer and refrigerant pressure drop characteristics as evaporators. The overall heat transfer coefficient for each of the two heat exchangers was found to be a strong function of both the water and refrigerant flow rates and a relatively weak function of the refrigerant evaporation temperature. The refrigerant pressure drop was determined to be highly dependent on the refrigerant flow rate and only slightly dependent on the evaporator temperature. The overall heat transfer coefficient showed an apparent difference between parallel and counter flow conditions. This coefficient, as defined by the log-mean temperature difference, was slightly higher for the counter flow condition. A numerical model of the evaporator was developed and compared with the experimental results. The model follows a numerical solution in which the governing equations (continuity, momentum, and energy) are solved for a finite control volume and an appropriate finitedifference scheme is used to continue the solution step-wise along the length of the heat exchanger. The numerical model accurately predicts the effect of flow rate and temperature on refrigerant pressure drop and the effect of water flow rate and direction on the overall heat transfer coefficient. The model does not accurately predict the effect of evaporator temperature and refrigerant flow rate on the heat transfer coefficient. Title: Experimental evaluation and numerical modeling of a water source heat pump evaporator Author: Means, Paul Morency Water source heat pumps are increasingly being used for residential and commercial space heating. Typically, these heat pumps are capable of both heating and cooling, and historically the design emphasis has been on improving the units' cooling performance. Recently, there has been more interest in improving the heating performance, however, in order to optimize the design for improved heating performance data on the heat pump components operating in the heating mode are required. These data have not been available for the waterto- refrigerant heat exchangers typically installed in unitary water source heat pumps. The purpose of this work is to provide performance data on such heat exchangers operating as evaporators (data is available for the heat exchangers operating as condensers) and to provide a numerical model by which a limited amount of evaporator data might be expanded for system modeling and optimization studies. A well instrumented water-to-water heat pump was assembled for the purpose of testing two such water-to-refrigerant heat exchangers to determine their heat transfer and refrigerant pressure drop characteristics as evaporators. The overall heat transfer coefficient for each of the two heat exchangers was found to be a strong function of both the water and refrigerant flow rates and a relatively weak function of the refrigerant evaporation temperature. The refrigerant pressure drop was determined to be highly dependent on the refrigerant flow rate and only slightly dependent on the evaporator temperature. The overall heat transfer coefficient showed an apparent difference between parallel and counter flow conditions. This coefficient, as defined by the log-mean temperature difference, was slightly higher for the counter flow condition. A numerical model of the evaporator was developed and compared with the experimental results. The model follows a numerical solution in which the governing equations (continuity, momentum, and energy) are solved for a finite control volume and an appropriate finitedifference scheme is used to continue the solution step-wise along the length of the heat exchanger. The numerical model accurately predicts the effect of flow rate and temperature on refrigerant pressure drop and the effect of water flow rate and direction on the overall heat transfer coefficient. The model does not accurately predict the effect of evaporator temperature and refrigerant flow rate on the heat transfer coefficient. Close

• 47. [Article] A numerical model for the fate and transport of chlorinated phenols in groundwater

  The objective of this study was to develop a numerical model for the movement and fate of chlorinated phenols in groundwater. In the first part, a numerical model for several different equilibrium and ...

  Citation × Citation Citation Abstract Copy Title: A numerical model for the fate and transport of chlorinated phenols in groundwater Author: Lee, Sang Bong The objective of this study was to develop a numerical model for the movement and fate of chlorinated phenols in groundwater. In the first part, a numerical model for several different equilibrium and nonequilibrium sorption processes under isothermal conditions is developed for one-dimensional, steady-state water flow in soil columns. The simulated breakthrough curves can be used to estimate sorption parameters from the results of column experiments. The second part presents a one-dimensional numerical model for the fate and transport of chlorinated phenols for one-dimensional, steady-state groundwater flow. The numerical model includes the transport processes of advection, dispersion, sorption, biological degradation, and decay. The set of governing differential equations is solved by Newton-Raphson iteration and the finite difference method. Two different groups of microorganisms are assumed to be involved in the degradation; one group for the reductive dechlorination of the electron acceptor/donor pair and the other group for the fermentation of the electron donor. Inhibition effects due to presence of multiple substrates are included in the Monod kinetics. Simulated breakthrough curves are presented for a range of assumed model parameters and will be compared with measured concentrations in a series of miscible displacement experiments in laboratory columns. Title: A numerical model for the fate and transport of chlorinated phenols in groundwater Author: Lee, Sang Bong The objective of this study was to develop a numerical model for the movement and fate of chlorinated phenols in groundwater. In the first part, a numerical model for several different equilibrium and nonequilibrium sorption processes under isothermal conditions is developed for one-dimensional, steady-state water flow in soil columns. The simulated breakthrough curves can be used to estimate sorption parameters from the results of column experiments. The second part presents a one-dimensional numerical model for the fate and transport of chlorinated phenols for one-dimensional, steady-state groundwater flow. The numerical model includes the transport processes of advection, dispersion, sorption, biological degradation, and decay. The set of governing differential equations is solved by Newton-Raphson iteration and the finite difference method. Two different groups of microorganisms are assumed to be involved in the degradation; one group for the reductive dechlorination of the electron acceptor/donor pair and the other group for the fermentation of the electron donor. Inhibition effects due to presence of multiple substrates are included in the Monod kinetics. Simulated breakthrough curves are presented for a range of assumed model parameters and will be compared with measured concentrations in a series of miscible displacement experiments in laboratory columns. Close

• 48. [Article] Sub-regional detention siting : a methodology using GIS

  The Mt. Scott watershed in northern Clackamas County, Oregon is an urban watershed that lies inside the Portland metropolitan urban growth boundary. Urbanization of the watershed began in the early 1970s ...

  Citation × Citation Citation Abstract Copy Title: Sub-regional detention siting : a methodology using GIS Author: Murdock, Carol L. The Mt. Scott watershed in northern Clackamas County, Oregon is an urban watershed that lies inside the Portland metropolitan urban growth boundary. Urbanization of the watershed began in the early 1970s and has recently accelerated. A landscape level analysis of the urbanization process was combined with the results of a recently completed storm water master plan for the area. The project resulted in the identification of potential locations for combined detention and water quality facilities. It also served to further justify the recent revision of surface water management rules and regulations to include requirements for lower release rates from detention facilities and riparian and wetland buffers. Geographic Information Systems (GIS) was used extensively throughout the project to provide data input into the XPSWMM model that was used to analyze storm water flows and to identify infrastructure needs and requirements. In addition, GIS played a pivotal role in identifying factors which may be contributing to changes in stream condition in the basin. The results of this analysis project will be used by surface water managers in their continuing effort to refine current surface water management rules and regulations in the face of on-going development and continued urbanization. Title: Sub-regional detention siting : a methodology using GIS Author: Murdock, Carol L. The Mt. Scott watershed in northern Clackamas County, Oregon is an urban watershed that lies inside the Portland metropolitan urban growth boundary. Urbanization of the watershed began in the early 1970s and has recently accelerated. A landscape level analysis of the urbanization process was combined with the results of a recently completed storm water master plan for the area. The project resulted in the identification of potential locations for combined detention and water quality facilities. It also served to further justify the recent revision of surface water management rules and regulations to include requirements for lower release rates from detention facilities and riparian and wetland buffers. Geographic Information Systems (GIS) was used extensively throughout the project to provide data input into the XPSWMM model that was used to analyze storm water flows and to identify infrastructure needs and requirements. In addition, GIS played a pivotal role in identifying factors which may be contributing to changes in stream condition in the basin. The results of this analysis project will be used by surface water managers in their continuing effort to refine current surface water management rules and regulations in the face of on-going development and continued urbanization. Close

• 49. [Article] Tillamook Bay comprehensive conservation and mangement plan : restoring the balance

  Citation × Citation Citation Abstract Copy Title: Tillamook Bay comprehensive conservation and mangement plan : restoring the balance Title: Tillamook Bay comprehensive conservation and mangement plan : restoring the balance Close

• 50. [Article] Shelfbreak upwelling induced by alongshore currents: analytical and numerical results

  This is the publisher's version of record. The original submission is copyrighted by Cambridge University Press and can be found here: http://www.tos.org/

  Citation × Citation Citation Abstract Copy Title: Shelfbreak upwelling induced by alongshore currents: analytical and numerical results Author: Palma, Elbio D., Miller, Robert N., Matano, Ricardo P. This is the publisher's version of record. The original submission is copyrighted by Cambridge University Press and can be found here: http://www.tos.org/ Title: Shelfbreak upwelling induced by alongshore currents: analytical and numerical results Author: Palma, Elbio D., Miller, Robert N., Matano, Ricardo P. This is the publisher's version of record. The original submission is copyrighted by Cambridge University Press and can be found here: http://www.tos.org/ Close