The Experts below are selected from a list of 44034 Experts worldwide ranked by ideXlab platform
Kenneth T. Belt - One of the best experts on this subject based on the ideXlab platform.
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Longitudinal patterns in carbon and nitrogen fluxes and stream metabolism along an urban watershed Continuum
Biogeochemistry, 2014Co-Authors: Sujay S Kaushal, Katie Delaney-newcomb, Stuart E. G. Findlay, Tamara A. Newcomer, Shuiwang Duan, Michael J. Pennino, Gwendolyn M. Sivirichi, Ashley M. Sides-raley, Mark R. Walbridge, Kenneth T. BeltAbstract:An urban watershed Continuum Framework hypothesizes that there are coupled changes in (1) carbon and nitrogen cycling, (2) groundwater-surface water interactions, and (3) ecosystem metabolism along broader hydrologic flowpaths. It expands our understanding of urban streams beyond a reach scale. We evaluated this Framework by analyzing longitudinal patterns in: C and N concentrations and mass balances, groundwater-surface interactions, and stream metabolism and carbon quality from headwaters to larger order streams. 52 monitoring sites were sampled seasonally and monthly along the Gwynns Falls watershed, which drains 170 km^2 of the Baltimore Long-Term Ecological Research site. Regarding our first hypothesis of coupled C and N cycles, there were significant inverse linear relationships between nitrate and dissolved organic carbon (DOC) and nitrogen longitudinally ( P
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The urban watershed Continuum: evolving spatial and temporal dimensions
Urban Ecosystems, 2012Co-Authors: Sujay S Kaushal, Kenneth T. BeltAbstract:Urban ecosystems are constantly evolving, and they are expected to change in both space and time with active management or degradation. An urban watershed Continuum Framework recognizes a Continuum of engineered and natural hydrologic flowpaths that expands hydrologic networks in ways that are seldom considered. It recognizes that the nature of hydrologic connectivity influences downstream fluxes and transformations of carbon, contaminants, energy, and nutrients across 4 space and time dimensions. Specifically, it proposes that (1) first order streams are largely replaced by urban infrastructure (e.g. storm drains, ditches, gutters, pipes) longitudinally and laterally within watersheds, (2) there is extensive longitudinal and lateral modification of organic carbon and nutrient retention in engineered headwaters (3) there are longitudinal downstream pulses in material and energy exports that are amplified by interactive land-use and hydrologic variability, (4) there are vertical interactions between leaky pipes and ground water that influence stream solute transport, (5) the urban watershed Continuum is a transformer and transporter of materials and energy based on hydrologic residence times, and (6) temporally, there is an evolution of biogeochemical cycles and ecosystem functions as land use and urban infrastructure change over time. We provide examples from the Baltimore Ecosystem Study Long-Term Ecological (LTER) site along 4 spatiotemporal dimensions. Long-term monitoring indicates that engineered headwaters increase downstream subsidies of nitrate, phosphate, sulfate, carbon, and metals compared with undeveloped headwaters. There are increased longitudinal transformations of carbon and nitrogen from suburban headwaters to more urbanized receiving waters. Hydrologic connectivity along the vertical dimension between ground water and leaky pipes from Baltimore’s aging infrastructure elevates stream solute concentrations. Across time, there has been increased headwater stream burial, evolving stormwater management, and long-term salinization of Baltimore’s drinking water supply. Overall, an urban watershed Continuum Framework proposes testable hypotheses of how transport/transformation of materials and energy vary along a Continuum of engineered and natural hydrologic flowpaths in space and time. Given interest in transitioning from sanitary to sustainable cities, it is necessary to recognize the evolving relationship between infrastructure and ecosystem function along the urban watershed Continuum.
Sujay S Kaushal - One of the best experts on this subject based on the ideXlab platform.
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Longitudinal patterns in carbon and nitrogen fluxes and stream metabolism along an urban watershed Continuum
Biogeochemistry, 2014Co-Authors: Sujay S Kaushal, Katie Delaney-newcomb, Stuart E. G. Findlay, Tamara A. Newcomer, Shuiwang Duan, Michael J. Pennino, Gwendolyn M. Sivirichi, Ashley M. Sides-raley, Mark R. Walbridge, Kenneth T. BeltAbstract:An urban watershed Continuum Framework hypothesizes that there are coupled changes in (1) carbon and nitrogen cycling, (2) groundwater-surface water interactions, and (3) ecosystem metabolism along broader hydrologic flowpaths. It expands our understanding of urban streams beyond a reach scale. We evaluated this Framework by analyzing longitudinal patterns in: C and N concentrations and mass balances, groundwater-surface interactions, and stream metabolism and carbon quality from headwaters to larger order streams. 52 monitoring sites were sampled seasonally and monthly along the Gwynns Falls watershed, which drains 170 km^2 of the Baltimore Long-Term Ecological Research site. Regarding our first hypothesis of coupled C and N cycles, there were significant inverse linear relationships between nitrate and dissolved organic carbon (DOC) and nitrogen longitudinally ( P
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The urban watershed Continuum: evolving spatial and temporal dimensions
Urban Ecosystems, 2012Co-Authors: Sujay S Kaushal, Kenneth T. BeltAbstract:Urban ecosystems are constantly evolving, and they are expected to change in both space and time with active management or degradation. An urban watershed Continuum Framework recognizes a Continuum of engineered and natural hydrologic flowpaths that expands hydrologic networks in ways that are seldom considered. It recognizes that the nature of hydrologic connectivity influences downstream fluxes and transformations of carbon, contaminants, energy, and nutrients across 4 space and time dimensions. Specifically, it proposes that (1) first order streams are largely replaced by urban infrastructure (e.g. storm drains, ditches, gutters, pipes) longitudinally and laterally within watersheds, (2) there is extensive longitudinal and lateral modification of organic carbon and nutrient retention in engineered headwaters (3) there are longitudinal downstream pulses in material and energy exports that are amplified by interactive land-use and hydrologic variability, (4) there are vertical interactions between leaky pipes and ground water that influence stream solute transport, (5) the urban watershed Continuum is a transformer and transporter of materials and energy based on hydrologic residence times, and (6) temporally, there is an evolution of biogeochemical cycles and ecosystem functions as land use and urban infrastructure change over time. We provide examples from the Baltimore Ecosystem Study Long-Term Ecological (LTER) site along 4 spatiotemporal dimensions. Long-term monitoring indicates that engineered headwaters increase downstream subsidies of nitrate, phosphate, sulfate, carbon, and metals compared with undeveloped headwaters. There are increased longitudinal transformations of carbon and nitrogen from suburban headwaters to more urbanized receiving waters. Hydrologic connectivity along the vertical dimension between ground water and leaky pipes from Baltimore’s aging infrastructure elevates stream solute concentrations. Across time, there has been increased headwater stream burial, evolving stormwater management, and long-term salinization of Baltimore’s drinking water supply. Overall, an urban watershed Continuum Framework proposes testable hypotheses of how transport/transformation of materials and energy vary along a Continuum of engineered and natural hydrologic flowpaths in space and time. Given interest in transitioning from sanitary to sustainable cities, it is necessary to recognize the evolving relationship between infrastructure and ecosystem function along the urban watershed Continuum.
Linda Squiers - One of the best experts on this subject based on the ideXlab platform.
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the nci s cancer information service s research Continuum Framework integrating research into cancer education practice 1999 2004
Journal of Cancer Education, 2007Co-Authors: Linda Fleisher, Julie Kornfeld, Sharon Mpa Davis, Marion E Morra, Linda SquiersAbstract:Between 1999 and 2004, the National Cancer Institute’s (NCI) Cancer Information Service’s (CIS) Research Initiative supported over 50 research projects representing a broad range of activities from research capacity building, development, implementation to diffusion and dissemination. These research activities are represented in the CIS Research Continuum Framework which the authors describe through a number of short case studies. Based on the experiences and successes of the CIS, other professionals working in the cancer field might consider consider establishing collaborative relationships across the research Continuum and participating in research that has relevancy to advances in cancer education.
Mahmoud Kadkhodaei - One of the best experts on this subject based on the ideXlab platform.
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Thermomechanical Modeling of Stress Relaxation in Shape Memory Alloy Wires
Journal of Materials Engineering and Performance, 2015Co-Authors: Fateme Zare, Mahmoud Kadkhodaei, Iman SalafianAbstract:When a shape memory alloy (SMA) is subjected to a mechanical load, especially at high strain rates, its temperature varies due to thermomechanical coupling in the response of these materials. Thus, if strain is kept constant during the transformation, temperature change will cause stress to decrease during loading and to increase during unloading. A decrease in stress under constant strain indicates stress relaxation, and an increase in stress indicates stress recovery, i.e., reverse stress relaxation. In this paper, a fully coupled thermomechanical model is developed in a Continuum Framework to study stress relaxation and stress recovery in SMA wires. Numerical simulations at different ambient temperatures, applied strain rates, wire radii, and relaxation intervals are done to show the abilities of the proposed model in predicting relaxation phenomena in various conditions where strain remains constant during loading or unloading. Relaxation experiments were also performed on NiTi wires, and the numerical and empirical results are shown to be in a good agreement.
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A geometrical approach to determine reorientation start and continuation conditions in ferromagnetic shape memory alloys considering the effects of loading history
Smart Materials and Structures, 2014Co-Authors: Milad Shirani, Mahmoud KadkhodaeiAbstract:Ferromagnetic shape memory alloys (FSMAs) and magnetic shape memory alloys (MSMAs) are metallic alloys that can undergo inelastic responses when exposed to magnetic fields. Several constitutive models have been proposed so far to model the behaviors of FSMAs. In this work, the effects of loading history on reorientation start conditions are considered, and it is shown that reorientation start conditions are not fixed values; rather, they change with respect to the amount of loading history. To consider the effects of loading history on reorientation start conditions, an available phase diagram in stress-field space is generalized to reorientation surfaces in stress-field-loading history space. Correspondingly, kinetic laws are derived in a Continuum Framework to be used with the reorientation surfaces to determine the amount of the martensitic variant 2 volume fraction. Based on the geometry of the reorientation surfaces, conditions that must be satisfied to ensure the continuation of reorientations are obtained. Available experimental findings validate the proposed model and the reorientation surfaces.
Linda Fleisher - One of the best experts on this subject based on the ideXlab platform.
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the nci s cancer information service s research Continuum Framework integrating research into cancer education practice 1999 2004
Journal of Cancer Education, 2007Co-Authors: Linda Fleisher, Julie Kornfeld, Sharon Mpa Davis, Marion E Morra, Linda SquiersAbstract:Between 1999 and 2004, the National Cancer Institute’s (NCI) Cancer Information Service’s (CIS) Research Initiative supported over 50 research projects representing a broad range of activities from research capacity building, development, implementation to diffusion and dissemination. These research activities are represented in the CIS Research Continuum Framework which the authors describe through a number of short case studies. Based on the experiences and successes of the CIS, other professionals working in the cancer field might consider consider establishing collaborative relationships across the research Continuum and participating in research that has relevancy to advances in cancer education.