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• 41. [Article] A 30-Year Record of the Isotopic Composition of Atmospheric Methane

  Methane (CH4) is one of the most important greenhouse gases after water vapor and carbon dioxide due to its high concentration and global warming potential 25 times than that of CO2 (based on a 100 year ...

  Citation × Citation Citation Abstract Copy Title: A 30-Year Record of the Isotopic Composition of Atmospheric Methane Author: Teama, Doaa Galal Mohammed Year: 2013 Methane (CH4) is one of the most important greenhouse gases after water vapor and carbon dioxide due to its high concentration and global warming potential 25 times than that of CO2 (based on a 100 year time horizon). Its atmospheric concentration has more than doubled from the preindustrial era due to anthropogenic activities such as rice cultivation, biomass burning, and fossil fuel production. However, the rate of increase of atmospheric CH4 (or the growth rate) slowed from 1980 until present. The main reason for this trend is a slowdown in the trend of CH4 sources. Measuring stable isotopes of atmospheric CH4 can constrain changes of CH4 sources. The main goal of this work is to interpret the CH4 trend from 1978-2010 in terms of its sources using measurements of CH4 mixing ratio and its isotopes. The current work presents the measurements and analysis of CH4 and its isotopes (δ13C and δD) of four air archive sample sets collected by the Oregon Graduate Institute (OGI). CH4 isotope ratios (δ13C and δD) were measured by a continuous flow isotope ratio mass spectrometer technique developed at PSU. The first set is for Cape Meares, Oregon which is the oldest and longest set and spans 1977-1999. The integrity of this sample set was evaluated by comparing between our measured CH4 mixing ratio values with those measured values by OGI and was found to be stable. Resulting CH4 seasonal cycle was evaluated from the Cape Meares data. The CH4 seasonal cycle shows a broad maximum during October-April and a minimum between July and August. The seasonal cycles of δ13C and δD have maximum values in May for δ13C and in July for δD and minimum values between September-October for δ13C and in October for δD. These results indicate a CH4 source that is more enriched January-May (e.g. biomass burning) and a source that is more depleted August-October (e.g. microbial). In addition to Cape Meares, air archive sets were analyzed from: South Pole (SPO), Samoa (SMO), Mauna Loa (MLO) 1992-1996. The presented δD measurements are unique measured values during these time periods at these stations. To obtain the long-term in isotopic CH4 from 1978-2010, other datasets of Northern Hemisphere mid-latitude sites are included with Cape Meares. These sites are Olympic Peninsula, Washington; Montaña de Oro, California; and Niwot Ridge, Colorado. The seasonal cycles of CH4 and its isotopes from the composite dataset have the same phase and amplitudes as the Cape Meares site. CH4 growth rate shows a decrease over time 1978-2010 with three main spikes in 1992, 1998, and 2003 consistent with the literature from the global trend. CH4 lifetime is estimated to 9.7 yrs. The δ13C trend in the composite data shows a slow increase from 1978-1987, a more rapid rate of change 1987-2005, and a gradual depletion during 2005-2010. The δD trend in the composite data shows a gradual increase during 1978-2001 and decrease from 2001-2005. From these results, the global CH4 emissions are estimated and show a leveling off sources 1982-2010 with two large peak anomalies in 1998 and 2003. The global average δ13C and δD of CH4 sources are estimated from measured values. The results of these calculations indicate that there is more than one source which controls the decrease in the global CH4 trend. From 1982-2001, δ13C and δD of CH4 sources becomes more depleted due to a decrease in fossil and/or biomass burning sources relative to microbial sources. From 2005-2010, δ13C of CH4 sources returns to its 1981 value. There are two significant peaks in δ13C and δD of CH4 sources in 1998 and 2003 due to the wildfire emissions in boreal areas and in Europe. Title: A 30-Year Record of the Isotopic Composition of Atmospheric Methane Author: Teama, Doaa Galal Mohammed Year: 2013 Methane (CH4) is one of the most important greenhouse gases after water vapor and carbon dioxide due to its high concentration and global warming potential 25 times than that of CO2 (based on a 100 year time horizon). Its atmospheric concentration has more than doubled from the preindustrial era due to anthropogenic activities such as rice cultivation, biomass burning, and fossil fuel production. However, the rate of increase of atmospheric CH4 (or the growth rate) slowed from 1980 until present. The main reason for this trend is a slowdown in the trend of CH4 sources. Measuring stable isotopes of atmospheric CH4 can constrain changes of CH4 sources. The main goal of this work is to interpret the CH4 trend from 1978-2010 in terms of its sources using measurements of CH4 mixing ratio and its isotopes. The current work presents the measurements and analysis of CH4 and its isotopes (δ13C and δD) of four air archive sample sets collected by the Oregon Graduate Institute (OGI). CH4 isotope ratios (δ13C and δD) were measured by a continuous flow isotope ratio mass spectrometer technique developed at PSU. The first set is for Cape Meares, Oregon which is the oldest and longest set and spans 1977-1999. The integrity of this sample set was evaluated by comparing between our measured CH4 mixing ratio values with those measured values by OGI and was found to be stable. Resulting CH4 seasonal cycle was evaluated from the Cape Meares data. The CH4 seasonal cycle shows a broad maximum during October-April and a minimum between July and August. The seasonal cycles of δ13C and δD have maximum values in May for δ13C and in July for δD and minimum values between September-October for δ13C and in October for δD. These results indicate a CH4 source that is more enriched January-May (e.g. biomass burning) and a source that is more depleted August-October (e.g. microbial). In addition to Cape Meares, air archive sets were analyzed from: South Pole (SPO), Samoa (SMO), Mauna Loa (MLO) 1992-1996. The presented δD measurements are unique measured values during these time periods at these stations. To obtain the long-term in isotopic CH4 from 1978-2010, other datasets of Northern Hemisphere mid-latitude sites are included with Cape Meares. These sites are Olympic Peninsula, Washington; Montaña de Oro, California; and Niwot Ridge, Colorado. The seasonal cycles of CH4 and its isotopes from the composite dataset have the same phase and amplitudes as the Cape Meares site. CH4 growth rate shows a decrease over time 1978-2010 with three main spikes in 1992, 1998, and 2003 consistent with the literature from the global trend. CH4 lifetime is estimated to 9.7 yrs. The δ13C trend in the composite data shows a slow increase from 1978-1987, a more rapid rate of change 1987-2005, and a gradual depletion during 2005-2010. The δD trend in the composite data shows a gradual increase during 1978-2001 and decrease from 2001-2005. From these results, the global CH4 emissions are estimated and show a leveling off sources 1982-2010 with two large peak anomalies in 1998 and 2003. The global average δ13C and δD of CH4 sources are estimated from measured values. The results of these calculations indicate that there is more than one source which controls the decrease in the global CH4 trend. From 1982-2001, δ13C and δD of CH4 sources becomes more depleted due to a decrease in fossil and/or biomass burning sources relative to microbial sources. From 2005-2010, δ13C of CH4 sources returns to its 1981 value. There are two significant peaks in δ13C and δD of CH4 sources in 1998 and 2003 due to the wildfire emissions in boreal areas and in Europe. Close

• 42. [Article] Oxygen Demand Trends, Land Cover Change, and Water Quality Management for an Urbanizing Oregon Watershed

  In-stream aquatic habitat depends on adequate levels of dissolved oxygen. Human alteration of the landscape has an extensive influence on the biogeochemical processes that drive oxygen cycling in streams. ...

  Citation × Citation Citation Abstract Copy Title: Oxygen Demand Trends, Land Cover Change, and Water Quality Management for an Urbanizing Oregon Watershed Author: Boeder, Michael Karl Year: 2006 In-stream aquatic habitat depends on adequate levels of dissolved oxygen. Human alteration of the landscape has an extensive influence on the biogeochemical processes that drive oxygen cycling in streams. Historic datasets allow researchers to track trends in chemical parameters concomitant with urbanization, while land cover change analysis allows researchers to identify linkages between water quality trends and landscape change. Using the Seasonal Kendall's test, I examined water quality trends in oxygen demand variables during the mid-1990s to 2003, for twelve sites in the Rock Creek sub-watershed of the Tualatin River, northwest Oregon. Significant trends occurred in each parameter. Dissolved oxygen (DO (%sat)) increased at five sites. Chemical oxygen demand (COD) decreased at seven sites. Total Kjeldahl nitrogen (TKN) decreased at five sites and increased at one site. Ammonium (NH3-N) decreased at one site and increased at one site. Multiple linear regression indicates that nitrogenous oxygen demand accounts for a significant amount of variance in COD at ten of the twelve sites (adjusted R2values from 0.14 to 0.73). Aerial photo interpretation revealed significant land cover change in agricultural land cover (-8% for the entire basin area) and residential land cover (+10% for the entire basin area). Correlation results between seasonal oxygen demand data and land cover values at multiple scales indicated that: (I) forest cover negatively influences COD at the full sub-basin scale and positively influences NH3-N at local scales, (2) residential land cover positively influences DO (%sat) values at local scales, (3) agricultural land cover does not influence oxygen demand at any land cover assessment scale, ( 4) local topography negatively influences TKN and NH3-N, and (5) urban runoff management infrastructure correlates positively with COD. Study results indicate that, with the exception of forested land, local scale land cover and landscape variables dominate influence on oxygen demand in the Rock Creek basin. Since DO conditions have improved in these streams, watershed management efforts should emphasize local influences in order to continue to maintain stream health. Title: Oxygen Demand Trends, Land Cover Change, and Water Quality Management for an Urbanizing Oregon Watershed Author: Boeder, Michael Karl Year: 2006 In-stream aquatic habitat depends on adequate levels of dissolved oxygen. Human alteration of the landscape has an extensive influence on the biogeochemical processes that drive oxygen cycling in streams. Historic datasets allow researchers to track trends in chemical parameters concomitant with urbanization, while land cover change analysis allows researchers to identify linkages between water quality trends and landscape change. Using the Seasonal Kendall's test, I examined water quality trends in oxygen demand variables during the mid-1990s to 2003, for twelve sites in the Rock Creek sub-watershed of the Tualatin River, northwest Oregon. Significant trends occurred in each parameter. Dissolved oxygen (DO (%sat)) increased at five sites. Chemical oxygen demand (COD) decreased at seven sites. Total Kjeldahl nitrogen (TKN) decreased at five sites and increased at one site. Ammonium (NH3-N) decreased at one site and increased at one site. Multiple linear regression indicates that nitrogenous oxygen demand accounts for a significant amount of variance in COD at ten of the twelve sites (adjusted R2values from 0.14 to 0.73). Aerial photo interpretation revealed significant land cover change in agricultural land cover (-8% for the entire basin area) and residential land cover (+10% for the entire basin area). Correlation results between seasonal oxygen demand data and land cover values at multiple scales indicated that: (I) forest cover negatively influences COD at the full sub-basin scale and positively influences NH3-N at local scales, (2) residential land cover positively influences DO (%sat) values at local scales, (3) agricultural land cover does not influence oxygen demand at any land cover assessment scale, ( 4) local topography negatively influences TKN and NH3-N, and (5) urban runoff management infrastructure correlates positively with COD. Study results indicate that, with the exception of forested land, local scale land cover and landscape variables dominate influence on oxygen demand in the Rock Creek basin. Since DO conditions have improved in these streams, watershed management efforts should emphasize local influences in order to continue to maintain stream health. Close

• 43. [Article] Climate Change and Freshwater Resources in Oregon

  Climate change will affect various sectors of water resources in Oregon in the 21st century. The observed trends in streamflow show significant declines in September flow and, although not significant, ...

  Citation × Citation Citation Abstract Copy Title: Climate Change and Freshwater Resources in Oregon Author: Chang, Heejun, Jones, Julie Year: 2010 Climate change will affect various sectors of water resources in Oregon in the 21st century. The observed trends in streamflow show significant declines in September flow and, although not significant, increases in March flow in many transient rain-snow basins. These streamflow trends are associated with rising temperature and coincident declines in snowpack in spring in the latter half of the 20th century. While there are no distinct trends in high precipitation events, such events are associated with climate variability such as ENSO and PDO. Effects of ENSO and PDO are more pronounced at the beginning and end of the wet season in the Willamette River basin. The amount and seasonality of water supply is projected to shift as the distribution of precipitation changes and temperatures rise. Higher summer air temperatures accompanied by reduced precipitation are projected to increase evapotranspiration and decrease stream flow in summer. Although there are no distinct spatial patterns of changes in precipitation and temperature across the State in the 21st century (uniform increase in temperature across the region), significant regional variations do exist. The magnitude of change depends on the importance of snow in the current water budget, so projected changes are greater for mountainous regions than for low-elevation areas. Transient rain-snow basins, such as those in the Western Cascade basins, are projected to be more sensitive to these changes in precipitation and temperature. The high Cascade basins that are primarily fed by deep groundwater systems could sustain low flow during summer months. Basins in the east of the Cascades are projected to have low summer flow in a distant future as groundwater recharge declines over time. April 1 snow water equivalent (SWE) will decline and the center timing of runoff will become earlier in transient rain-snow basins as snowpack is projected to decline consistently in the 21st century. These model projections should be viewed with caution for several reasons when considering climate change impacts on water supply in Oregon. First, this chapter shows that few consistent trends in runoff are apparent in streamflow records from Oregon; instead, the direction and magnitude of change in streamflow varies by season, by basin size, and among ecoregions in Oregon. Second, observed streamflow trends (e.g., declining flows in summer, or in September) may be explained by factors that may not be directly related to global climate change. For example, recent low-flow years are attributable to low precipitation years (especially 2001 and 2005) and perhaps to interannual variations in snowpack associated with cyclical variation in ocean temperatures, while long-term decreases in summer flows are attributable to the combination of summer precipitation decline and increasing water withdrawals for consumptive use. Third, model projections do not account for possible resilience and adaptations in natural ecosystems that may alter water use and lead to smaller than expected changes in streamflow. More work is needed on vegetation responses to climate variability, the interactions between soil water and vegetation, and the relationship between streamflow and precipitation (runoff ratios) in large basins. Title: Climate Change and Freshwater Resources in Oregon Author: Chang, Heejun, Jones, Julie Year: 2010 Climate change will affect various sectors of water resources in Oregon in the 21st century. The observed trends in streamflow show significant declines in September flow and, although not significant, increases in March flow in many transient rain-snow basins. These streamflow trends are associated with rising temperature and coincident declines in snowpack in spring in the latter half of the 20th century. While there are no distinct trends in high precipitation events, such events are associated with climate variability such as ENSO and PDO. Effects of ENSO and PDO are more pronounced at the beginning and end of the wet season in the Willamette River basin. The amount and seasonality of water supply is projected to shift as the distribution of precipitation changes and temperatures rise. Higher summer air temperatures accompanied by reduced precipitation are projected to increase evapotranspiration and decrease stream flow in summer. Although there are no distinct spatial patterns of changes in precipitation and temperature across the State in the 21st century (uniform increase in temperature across the region), significant regional variations do exist. The magnitude of change depends on the importance of snow in the current water budget, so projected changes are greater for mountainous regions than for low-elevation areas. Transient rain-snow basins, such as those in the Western Cascade basins, are projected to be more sensitive to these changes in precipitation and temperature. The high Cascade basins that are primarily fed by deep groundwater systems could sustain low flow during summer months. Basins in the east of the Cascades are projected to have low summer flow in a distant future as groundwater recharge declines over time. April 1 snow water equivalent (SWE) will decline and the center timing of runoff will become earlier in transient rain-snow basins as snowpack is projected to decline consistently in the 21st century. These model projections should be viewed with caution for several reasons when considering climate change impacts on water supply in Oregon. First, this chapter shows that few consistent trends in runoff are apparent in streamflow records from Oregon; instead, the direction and magnitude of change in streamflow varies by season, by basin size, and among ecoregions in Oregon. Second, observed streamflow trends (e.g., declining flows in summer, or in September) may be explained by factors that may not be directly related to global climate change. For example, recent low-flow years are attributable to low precipitation years (especially 2001 and 2005) and perhaps to interannual variations in snowpack associated with cyclical variation in ocean temperatures, while long-term decreases in summer flows are attributable to the combination of summer precipitation decline and increasing water withdrawals for consumptive use. Third, model projections do not account for possible resilience and adaptations in natural ecosystems that may alter water use and lead to smaller than expected changes in streamflow. More work is needed on vegetation responses to climate variability, the interactions between soil water and vegetation, and the relationship between streamflow and precipitation (runoff ratios) in large basins. Close

• 44. [Article] Urbanization and its Relationship to Water Quality within the Bronson Creek Watershed

  Urbanization and its Relationship to Water Quality within the Bronson Creek Watershed A watershed analysis project was undertaken to investigate the impact of urbanization on the water quality with Bronson ...

  Citation × Citation Citation Abstract Copy Title: Urbanization and its Relationship to Water Quality within the Bronson Creek Watershed Author: Creech, Jason Cristopher Year: 2003 Urbanization and its Relationship to Water Quality within the Bronson Creek Watershed A watershed analysis project was undertaken to investigate the impact of urbanization on the water quality with Bronson Creek; a small urban stream in the metropolitan area of Portland, Oregon. Total Maximum Daily Loads (TMDLs) have been established for several water quality parameters within the watershed. Water quality data were collected at nine sampling along Bronson Creek by Clean Water Services, a local public utility charged with storm water management and water quality protection duties. Only seven water quality parameters were included in the analysis; they were 1) temperature, 2) total phosphorous, 3) ortho-phosphate, 4) ammonia, 5) total nitrogen, 6) total suspended solids, and 7) E. Coli. Samples were taken approximately twice a month over a 7 year period from 1994 – 2001. Total impervious area (TIA) was used as the indicator of urbanization for the project. Impervious area values (TIA%) were calculated by digitizing aerial photography. Yearly TIA values were calculated for the entire watershed, as well as for its 37 subasins (subcatchement level). Water quality data were analyzed for variations along the stream and for the presence of trends (monotonic changes over time) during seasons of poor water quality. Kendall’s t was also used as the trend test statistic. Data were also analyzed to determine if an association exists between water quality at a sampling site and the upstream imperviousness (TIA%). Kendall’s t was used as the test statistic. Negative trends (improving water quality) were found throughout the watershed with nitrogen exhibiting the largest reduction. Temperature was the only parameter not to exhibit a negative trend at any location within the watershed. Results of the correlation between water quality and TIA% showed similar results, where a parameter experiencing a trend also exhibited a significant Kendall’s correlation with upstream TIA%. As TIA increased, water quality improved at least one site, for all parameters except temperature. One possible cause of the improving water quality within Bronson Creek is the implementation of best management practices within the watershed. Stormwater ponds were located in subcatchments that were adjacent to water quality sampling sites with improving water quality. The Bronson Creek watershed is also part of a pilot program to test the effectiveness of best management practices on improving water quality in the urban environment. Title: Urbanization and its Relationship to Water Quality within the Bronson Creek Watershed Author: Creech, Jason Cristopher Year: 2003 Urbanization and its Relationship to Water Quality within the Bronson Creek Watershed A watershed analysis project was undertaken to investigate the impact of urbanization on the water quality with Bronson Creek; a small urban stream in the metropolitan area of Portland, Oregon. Total Maximum Daily Loads (TMDLs) have been established for several water quality parameters within the watershed. Water quality data were collected at nine sampling along Bronson Creek by Clean Water Services, a local public utility charged with storm water management and water quality protection duties. Only seven water quality parameters were included in the analysis; they were 1) temperature, 2) total phosphorous, 3) ortho-phosphate, 4) ammonia, 5) total nitrogen, 6) total suspended solids, and 7) E. Coli. Samples were taken approximately twice a month over a 7 year period from 1994 – 2001. Total impervious area (TIA) was used as the indicator of urbanization for the project. Impervious area values (TIA%) were calculated by digitizing aerial photography. Yearly TIA values were calculated for the entire watershed, as well as for its 37 subasins (subcatchement level). Water quality data were analyzed for variations along the stream and for the presence of trends (monotonic changes over time) during seasons of poor water quality. Kendall’s t was also used as the trend test statistic. Data were also analyzed to determine if an association exists between water quality at a sampling site and the upstream imperviousness (TIA%). Kendall’s t was used as the test statistic. Negative trends (improving water quality) were found throughout the watershed with nitrogen exhibiting the largest reduction. Temperature was the only parameter not to exhibit a negative trend at any location within the watershed. Results of the correlation between water quality and TIA% showed similar results, where a parameter experiencing a trend also exhibited a significant Kendall’s correlation with upstream TIA%. As TIA increased, water quality improved at least one site, for all parameters except temperature. One possible cause of the improving water quality within Bronson Creek is the implementation of best management practices within the watershed. Stormwater ponds were located in subcatchments that were adjacent to water quality sampling sites with improving water quality. The Bronson Creek watershed is also part of a pilot program to test the effectiveness of best management practices on improving water quality in the urban environment. Close

• 45. [Article] A geophysical study of the North Scappoose Creek, Alder Creek, Clatskanie River lineament, along the trend of the Portland Hills fault, Columbia County, Oregon

  The Portland Hills fault forms a strong northwest trending lineament along the east side of the Tualatin Mountains. An en echelon lineament follows North Scappoose Creek, Alder Creek, and the Clatskanie ...

  Citation × Citation Citation Abstract Copy Title: A geophysical study of the North Scappoose Creek, Alder Creek, Clatskanie River lineament, along the trend of the Portland Hills fault, Columbia County, Oregon Author: Haas, Nina Year: 1982 The Portland Hills fault forms a strong northwest trending lineament along the east side of the Tualatin Mountains. An en echelon lineament follows North Scappoose Creek, Alder Creek, and the Clatskanie River along the same trend, through Columbia County, Oregon. The possibility that this lineament follows a fault or fault zone was investigated in this study. Geophysical methods were used, with seismic refraction, magnetic and gravity lines run perpendicular to the lineament. The seismic refraction models indicate the near surface basalt is broken in many places, with 15 - 30 meters (50 - 100 feet) vertical displacement, down to the west, at Bunker Hill along the Alder Creek fault. Gravity models required a faulted zone approximately two kilometers wide across the lineament. The proposed fault zone is more clearly defined in the south, becoming more diffuse and branching in the northern part of the study area. The Bouguer gravity values from this study distort the -40 milligal contour farther to the northwest than is shown on the Complete Bouguer Gravity Anomaly Map of Oregon {Berg and Thiruvathukal, 1967b). The existence of sharp topographic features and the geophysical evidence indicate fault activity along the zone. Title: A geophysical study of the North Scappoose Creek, Alder Creek, Clatskanie River lineament, along the trend of the Portland Hills fault, Columbia County, Oregon Author: Haas, Nina Year: 1982 The Portland Hills fault forms a strong northwest trending lineament along the east side of the Tualatin Mountains. An en echelon lineament follows North Scappoose Creek, Alder Creek, and the Clatskanie River along the same trend, through Columbia County, Oregon. The possibility that this lineament follows a fault or fault zone was investigated in this study. Geophysical methods were used, with seismic refraction, magnetic and gravity lines run perpendicular to the lineament. The seismic refraction models indicate the near surface basalt is broken in many places, with 15 - 30 meters (50 - 100 feet) vertical displacement, down to the west, at Bunker Hill along the Alder Creek fault. Gravity models required a faulted zone approximately two kilometers wide across the lineament. The proposed fault zone is more clearly defined in the south, becoming more diffuse and branching in the northern part of the study area. The Bouguer gravity values from this study distort the -40 milligal contour farther to the northwest than is shown on the Complete Bouguer Gravity Anomaly Map of Oregon {Berg and Thiruvathukal, 1967b). The existence of sharp topographic features and the geophysical evidence indicate fault activity along the zone. Close

• 46. [Article] Anxiety level of graduate students in social work

  This study was designed to determine (1) the trend of anxiety level of social work students, term by term, over the academic year; (2) the cyclical trend of anxiety level of social work students within ...

  Citation × Citation Citation Abstract Copy Title: Anxiety level of graduate students in social work Author: Kouidou-Giles, Sophia, McKee, George Albert Year: 1971 This study was designed to determine (1) the trend of anxiety level of social work students, term by term, over the academic year; (2) the cyclical trend of anxiety level of social work students within each term and (3) the effects of age and sex on level of anxiety among social work students. Anxiety was measured with the IPAT – 8 Parallel Form Anxiety Battery. This test was administered to twenty randomly selected first year students in the School of Social Work during the 1969-1970 academic year at Portland State University. Data was collected from six test administrations which took place at the beginning and the end of each term. Analysis of variance in a 2x2x2x3 factorial design simultaneously investigated all four variables. Some variation among these variables and their interactions was found, but only the “time of quarter” main effect reached statistical significance. A cyclical pattern of anxiety following a high-in-the-beginning, low-at-the-end of each term trend was observed. Anxiety, however, remained quite level over the three terms of the academic year. Nor was anxiety level related to differences in age or sex. These findings have led the authors to speculate that the uncertainty of a new situation at the beginning of each new term created more anxiety than did the final field evaluations, classroom examinations, papers or other outside influences such as the Kent State incidents etc., and that increased structuring at the beginning of each term might help to allay that anxiety. Perhaps it could be said that each individual’s role as a “social work graduate student” had a greater effect on his anxiety level than did sex, age, or important events not directly related to school expectations. Title: Anxiety level of graduate students in social work Author: Kouidou-Giles, Sophia, McKee, George Albert Year: 1971 This study was designed to determine (1) the trend of anxiety level of social work students, term by term, over the academic year; (2) the cyclical trend of anxiety level of social work students within each term and (3) the effects of age and sex on level of anxiety among social work students. Anxiety was measured with the IPAT – 8 Parallel Form Anxiety Battery. This test was administered to twenty randomly selected first year students in the School of Social Work during the 1969-1970 academic year at Portland State University. Data was collected from six test administrations which took place at the beginning and the end of each term. Analysis of variance in a 2x2x2x3 factorial design simultaneously investigated all four variables. Some variation among these variables and their interactions was found, but only the “time of quarter” main effect reached statistical significance. A cyclical pattern of anxiety following a high-in-the-beginning, low-at-the-end of each term trend was observed. Anxiety, however, remained quite level over the three terms of the academic year. Nor was anxiety level related to differences in age or sex. These findings have led the authors to speculate that the uncertainty of a new situation at the beginning of each new term created more anxiety than did the final field evaluations, classroom examinations, papers or other outside influences such as the Kent State incidents etc., and that increased structuring at the beginning of each term might help to allay that anxiety. Perhaps it could be said that each individual’s role as a “social work graduate student” had a greater effect on his anxiety level than did sex, age, or important events not directly related to school expectations. Close

• 47. [Article] Decreasing Emissions of Methane from Rice Agriculture

  Methane emissions from rice fields are controlled by several key factors. The most important are the application of organic soil amendments and water management: whether the fields are flooded intermittently ...

  Citation × Citation Citation Abstract Copy Title: Decreasing Emissions of Methane from Rice Agriculture Author: Khalil, M. A. K., Shearer, Martha J. Year: 2006 Methane emissions from rice fields are controlled by several key factors. The most important are the application of organic soil amendments and water management: whether the fields are flooded intermittently or continuously. The total annual emissions from any country or the world are thus affected by the area of rice harvested, and a composite emission factor that takes into account how the various agricultural practices are distributed in terms of fertilizer use and water management, as well as other less important variables. Over decades the area of rice harvested changes but so does the composite emission factor. The product therefore, may change substantially over decadal time scales. We will argue that for China at least, there are downward trends of both area and emission factor leading to a substantial reduction of annual emissions over the last two decades from some 30 Tg/yr to perhaps less than 10 Tg/yr. The changes that cause these reductions would increase nitrous oxide emissions from rice fields as organic fertilizers are replaced with nitrogen based fertilizers. Similar changes are likely to be occurring world-wide. These trends of emissions are probably represented in the observed slowdown of methane trend in the atmosphere and the continuing steady increase of nitrous oxide. Title: Decreasing Emissions of Methane from Rice Agriculture Author: Khalil, M. A. K., Shearer, Martha J. Year: 2006 Methane emissions from rice fields are controlled by several key factors. The most important are the application of organic soil amendments and water management: whether the fields are flooded intermittently or continuously. The total annual emissions from any country or the world are thus affected by the area of rice harvested, and a composite emission factor that takes into account how the various agricultural practices are distributed in terms of fertilizer use and water management, as well as other less important variables. Over decades the area of rice harvested changes but so does the composite emission factor. The product therefore, may change substantially over decadal time scales. We will argue that for China at least, there are downward trends of both area and emission factor leading to a substantial reduction of annual emissions over the last two decades from some 30 Tg/yr to perhaps less than 10 Tg/yr. The changes that cause these reductions would increase nitrous oxide emissions from rice fields as organic fertilizers are replaced with nitrogen based fertilizers. Similar changes are likely to be occurring world-wide. These trends of emissions are probably represented in the observed slowdown of methane trend in the atmosphere and the continuing steady increase of nitrous oxide. Close

• 48. [Article] Forecasting Microprocessor Technology in the Multicore Era Using TFDEA

  Technological advancements in the microprocessor industry are benchmarked and gauged against a set of diverse criteria, specific to the fabrication process, usage as well as achieved performance. Changing ...

  Citation × Citation Citation Abstract Copy Title: Forecasting Microprocessor Technology in the Multicore Era Using TFDEA Author: Durairajan, Saranya, Prado, Maria Ibarra, Rahimi, Noshad, Jahromi, Shabnam Razeghian Year: 2013 Technological advancements in the microprocessor industry are benchmarked and gauged against a set of diverse criteria, specific to the fabrication process, usage as well as achieved performance. Changing trends in the appeal factor as well as wide variety of growing application of microprocessors in different industries also have a defining impact in the advancement of the technological features in future. This study improves the previous investigation in forecasting microprocessors? technology and uses Technology Forecasting using Data Envelopment Analysis (TFDEA) methodology for an enhanced model. The study takes advantage of the recent microprocessor dataset including multi core processors, from a variety of resources including the dataset collected by Stanford University, the database made available by Standard Performance Evaluation Corporation (SPEC), and the specifications announcements by the microprocessor manufacturers such as Intel and AMD. The result of this study is a rate of change (RoC) that is obtained based on the recent design trends including the State-of-the-Art generation of multicore microprocessors and hence, is superior for forecasting the future microprocessor technology trends. The Rate of Change obtained provides the rate in which values of expected output performance or input requirements for the state of the art microprocessors change in future years and can be used to evaluate the competitiveness of the projects being researched and developed. Title: Forecasting Microprocessor Technology in the Multicore Era Using TFDEA Author: Durairajan, Saranya, Prado, Maria Ibarra, Rahimi, Noshad, Jahromi, Shabnam Razeghian Year: 2013 Technological advancements in the microprocessor industry are benchmarked and gauged against a set of diverse criteria, specific to the fabrication process, usage as well as achieved performance. Changing trends in the appeal factor as well as wide variety of growing application of microprocessors in different industries also have a defining impact in the advancement of the technological features in future. This study improves the previous investigation in forecasting microprocessors? technology and uses Technology Forecasting using Data Envelopment Analysis (TFDEA) methodology for an enhanced model. The study takes advantage of the recent microprocessor dataset including multi core processors, from a variety of resources including the dataset collected by Stanford University, the database made available by Standard Performance Evaluation Corporation (SPEC), and the specifications announcements by the microprocessor manufacturers such as Intel and AMD. The result of this study is a rate of change (RoC) that is obtained based on the recent design trends including the State-of-the-Art generation of multicore microprocessors and hence, is superior for forecasting the future microprocessor technology trends. The Rate of Change obtained provides the rate in which values of expected output performance or input requirements for the state of the art microprocessors change in future years and can be used to evaluate the competitiveness of the projects being researched and developed. Close

• 49. [Article] Combining and Aggregating Environmental Data for Status and Trend Assessments: Challenges and Approaches

  Increasingly, natural resource management agencies and nongovernmental organizations are sharing monitoring data across geographic and jurisdictional boundaries. Doing so improves their abilities to assess ...

  Citation × Citation Citation Abstract Copy Title: Combining and Aggregating Environmental Data for Status and Trend Assessments: Challenges and Approaches Author: Maas-Hebner, Kathleen G., Harte, Michael, Molina, Nancy, Hughes, Robert M., Schreck, Carl B., Yeakley, J. Alan Year: 2015 Increasingly, natural resource management agencies and nongovernmental organizations are sharing monitoring data across geographic and jurisdictional boundaries. Doing so improves their abilities to assess local-, regional-, and landscape-level environmental conditions, particularly status and trends, and to improve their ability to make short-and long-term management decisions. Status monitoring assesses the current condition of a population or environmental condition across an area. Monitoring for trends aims at monitoring changes in populations or environmental condition through time. We wrote this paper to inform agency and nongovernmental organization managers, analysts, and consultants regarding the kinds of environmental data that can be combined with suitable techniques and statistically aggregated for new assessments. By doing so, they can increase the (1) use of available data and (2) the validity and reliability of the assessments. Increased awareness of the difficulties inherent in combining and aggregating data for local-and regional-level analyses can increase the likelihood that future monitoring efforts will be modified and/or planned to accommodate data from multiple sources. Title: Combining and Aggregating Environmental Data for Status and Trend Assessments: Challenges and Approaches Author: Maas-Hebner, Kathleen G., Harte, Michael, Molina, Nancy, Hughes, Robert M., Schreck, Carl B., Yeakley, J. Alan Year: 2015 Increasingly, natural resource management agencies and nongovernmental organizations are sharing monitoring data across geographic and jurisdictional boundaries. Doing so improves their abilities to assess local-, regional-, and landscape-level environmental conditions, particularly status and trends, and to improve their ability to make short-and long-term management decisions. Status monitoring assesses the current condition of a population or environmental condition across an area. Monitoring for trends aims at monitoring changes in populations or environmental condition through time. We wrote this paper to inform agency and nongovernmental organization managers, analysts, and consultants regarding the kinds of environmental data that can be combined with suitable techniques and statistically aggregated for new assessments. By doing so, they can increase the (1) use of available data and (2) the validity and reliability of the assessments. Increased awareness of the difficulties inherent in combining and aggregating data for local-and regional-level analyses can increase the likelihood that future monitoring efforts will be modified and/or planned to accommodate data from multiple sources. Close

• 50. [Article] Utilizing High Resolution Bus GPS Data to Visualize and Identify Congestion Hot-spots in Urban

  Congestion and travel delay on urban roadways can influence the roadways’ operating costs and service attractiveness. This research used high-resolution bus data to examine sources of delay on urban arterials. ...

  Citation × Citation Citation Abstract Copy Title: Utilizing High Resolution Bus GPS Data to Visualize and Identify Congestion Hot-spots in Urban Author: Stoll, Nicholas B, Glick, Travis B, Figliozzi, Miguel Year: 2016 Congestion and travel delay on urban roadways can influence the roadways’ operating costs and service attractiveness. This research used high-resolution bus data to examine sources of delay on urban arterials. A set of tools was created to help visualize trends in bus behavior and movement; these tools allowed larger traffic trends to be visualized along urban corridors and streets. With buses as probes and examining aggregated bus behavior, contoured speed plots were used to understand the behavior of roadways outside the zone of influence of bus stops. Speed plots were used to discover trends and travel patterns with only a few days’ data. Congestion and speed variation were viewed by time of day, and plots helped to indicate delays caused by intersections, crosswalks, or bus stops. This type of information is important to transit authorities looking to improve bus running times and reliability. Congested areas were detected and ranked. Speed plots were used to reevaluate bus stop locations (e.g., near side versus far side) and to identify locations where improvement are needed (e.g., queue jump lanes). Transportation agencies can also benefit from this type of information because arterial performance measures are difficult to estimate. Title: Utilizing High Resolution Bus GPS Data to Visualize and Identify Congestion Hot-spots in Urban Author: Stoll, Nicholas B, Glick, Travis B, Figliozzi, Miguel Year: 2016 Congestion and travel delay on urban roadways can influence the roadways’ operating costs and service attractiveness. This research used high-resolution bus data to examine sources of delay on urban arterials. A set of tools was created to help visualize trends in bus behavior and movement; these tools allowed larger traffic trends to be visualized along urban corridors and streets. With buses as probes and examining aggregated bus behavior, contoured speed plots were used to understand the behavior of roadways outside the zone of influence of bus stops. Speed plots were used to discover trends and travel patterns with only a few days’ data. Congestion and speed variation were viewed by time of day, and plots helped to indicate delays caused by intersections, crosswalks, or bus stops. This type of information is important to transit authorities looking to improve bus running times and reliability. Congested areas were detected and ranked. Speed plots were used to reevaluate bus stop locations (e.g., near side versus far side) and to identify locations where improvement are needed (e.g., queue jump lanes). Transportation agencies can also benefit from this type of information because arterial performance measures are difficult to estimate. Close