The Experts below are selected from a list of 437913 Experts worldwide ranked by ideXlab platform
Stephen P. Hopkin - One of the best experts on this subject based on the ideXlab platform.
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effects of ph on the toxicity of cadmium copper lead and zinc to folsomia candida willem 1902 collembola in a standard Laboratory Test system
Chemosphere, 1996Co-Authors: Richard D Sandifer, Stephen P. HopkinAbstract:EC50s for cadmium, copper, lead and zinc were determined for juvenile production of Folsomia candida at pH6.0, 5.0 and 4.5 in a standard Laboratory Test system. In contrast to most previous studies where metal toxicity was increased at low pHs, in our experiments there was no clear relationship between soil acidity and EC50-reproduction in this species. The EC50-reproduction values (μg g−1) for cadmium and zinc were similar at all three pHs (pH6.0: Cd 590, Zn 900; pH5.0: Cd 780, Zn 600; pH4.5: Cd 480, Zn 590). In contaminated field sites adjacent to primary zinc smelters, zinc is invariably present in soils at concentrations of at least 50 times that of cadmium Thus deleterious effects of mixtures of these metals on populations of Collembola in such sites can be attributed to zinc rather than cadmium.
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effects of ph on the toxicity of cadmium copper lead and zinc to folsomia candida willem 1902 collembola in a standard Laboratory Test system
Chemosphere, 1996Co-Authors: Richard D Sandifer, Stephen P. HopkinAbstract:EC50s for cadmium, copper, lead and zinc were determined for juvenile production of Folsomia candida at pH6.0, 5.0 and 4.5 in a standard Laboratory Test system. In contrast to most previous studies where metal toxicity was increased at low pHs, in our experiments there was no clear relationship between soil acidity and EC50-reproduction in this species. The EC50-reproduction values (μg g−1) for cadmium and zinc were similar at all three pHs (pH6.0: Cd 590, Zn 900; pH5.0: Cd 780, Zn 600; pH4.5: Cd 480, Zn 590). In contaminated field sites adjacent to primary zinc smelters, zinc is invariably present in soils at concentrations of at least 50 times that of cadmium Thus deleterious effects of mixtures of these metals on populations of Collembola in such sites can be attributed to zinc rather than cadmium.
Jari Ihonen - One of the best experts on this subject based on the ideXlab platform.
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comparing anode gas recirculation with hydrogen purge and bleed in a novel pemfc Laboratory Test cell configuration
Fuel Cells, 2015Co-Authors: Pauli Koski, Luis C Perez, Jari IhonenAbstract:In automotive-type polymer electrolyte membrane fuel cell (PEMFC) systems, impurities and inert gases accumulate in the anode gas recirculation loop. Therefore, the impurity limits, dictated by the current hydrogen fuel specification (ISO 14687-2:2012), also require quantification with representative fuel cell Test systems applying anode gas recirculation, that enables high fuel utilization rates and accumulation of impurities.We report a novel PEMFC Laboratory Test cell configuration mimicking automotive conditions. This setup enabled comparison of two operation modes, hydrogen bleed and purge, within 84.4%–98.6% fuel utilizations. The results indicate that similar enrichment dynamics apply to both bleed and purge modes.The configuration employed a membrane dryer to circumvent the 60 °C limit of commercially available recirculation pumps. The membrane dryer allows heat and humidity extraction from the anode exit gas stream, enabling the adoption of conventional recirculation pumps, minimizing water condensation, and making sampling with on-line gas analysis instruments easier. The results show that anode gas recirculation systems with hydrogen bleed can be implemented in conventional Test stations by resorting to commercially available recirculation pumps. This enables realistic and cost-effective determination of impurity effects for fuel cell system development and new hydrogen fuel standards.
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comparing anode gas recirculation with hydrogen purge and bleed in a novel pemfc Laboratory Test cell configuration
Fuel Cells, 2015Co-Authors: Pauli Koski, Luis C Perez, Jari IhonenAbstract:In automotive-type polymer electrolyte membrane fuel cell (PEMFC) systems, impurities and inert gases accumulate in the anode gas recirculation loop. Therefore, the impurity limits, dictated by the current hydrogen fuel specification (ISO 14687-2:2012), also require quantification with representative fuel cell Test systems applying anode gas recirculation, that enables high fuel utilization rates and accumulation of impurities.We report a novel PEMFC Laboratory Test cell configuration mimicking automotive conditions. This setup enabled comparison of two operation modes, hydrogen bleed and purge, within 84.4%–98.6% fuel utilizations. The results indicate that similar enrichment dynamics apply to both bleed and purge modes.The configuration employed a membrane dryer to circumvent the 60 °C limit of commercially available recirculation pumps. The membrane dryer allows heat and humidity extraction from the anode exit gas stream, enabling the adoption of conventional recirculation pumps, minimizing water condensation, and making sampling with on-line gas analysis instruments easier. The results show that anode gas recirculation systems with hydrogen bleed can be implemented in conventional Test stations by resorting to commercially available recirculation pumps. This enables realistic and cost-effective determination of impurity effects for fuel cell system development and new hydrogen fuel standards.
Richard D Sandifer - One of the best experts on this subject based on the ideXlab platform.
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effects of ph on the toxicity of cadmium copper lead and zinc to folsomia candida willem 1902 collembola in a standard Laboratory Test system
Chemosphere, 1996Co-Authors: Richard D Sandifer, Stephen P. HopkinAbstract:EC50s for cadmium, copper, lead and zinc were determined for juvenile production of Folsomia candida at pH6.0, 5.0 and 4.5 in a standard Laboratory Test system. In contrast to most previous studies where metal toxicity was increased at low pHs, in our experiments there was no clear relationship between soil acidity and EC50-reproduction in this species. The EC50-reproduction values (μg g−1) for cadmium and zinc were similar at all three pHs (pH6.0: Cd 590, Zn 900; pH5.0: Cd 780, Zn 600; pH4.5: Cd 480, Zn 590). In contaminated field sites adjacent to primary zinc smelters, zinc is invariably present in soils at concentrations of at least 50 times that of cadmium Thus deleterious effects of mixtures of these metals on populations of Collembola in such sites can be attributed to zinc rather than cadmium.
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effects of ph on the toxicity of cadmium copper lead and zinc to folsomia candida willem 1902 collembola in a standard Laboratory Test system
Chemosphere, 1996Co-Authors: Richard D Sandifer, Stephen P. HopkinAbstract:EC50s for cadmium, copper, lead and zinc were determined for juvenile production of Folsomia candida at pH6.0, 5.0 and 4.5 in a standard Laboratory Test system. In contrast to most previous studies where metal toxicity was increased at low pHs, in our experiments there was no clear relationship between soil acidity and EC50-reproduction in this species. The EC50-reproduction values (μg g−1) for cadmium and zinc were similar at all three pHs (pH6.0: Cd 590, Zn 900; pH5.0: Cd 780, Zn 600; pH4.5: Cd 480, Zn 590). In contaminated field sites adjacent to primary zinc smelters, zinc is invariably present in soils at concentrations of at least 50 times that of cadmium Thus deleterious effects of mixtures of these metals on populations of Collembola in such sites can be attributed to zinc rather than cadmium.
Pauli Koski - One of the best experts on this subject based on the ideXlab platform.
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comparing anode gas recirculation with hydrogen purge and bleed in a novel pemfc Laboratory Test cell configuration
Fuel Cells, 2015Co-Authors: Pauli Koski, Luis C Perez, Jari IhonenAbstract:In automotive-type polymer electrolyte membrane fuel cell (PEMFC) systems, impurities and inert gases accumulate in the anode gas recirculation loop. Therefore, the impurity limits, dictated by the current hydrogen fuel specification (ISO 14687-2:2012), also require quantification with representative fuel cell Test systems applying anode gas recirculation, that enables high fuel utilization rates and accumulation of impurities.We report a novel PEMFC Laboratory Test cell configuration mimicking automotive conditions. This setup enabled comparison of two operation modes, hydrogen bleed and purge, within 84.4%–98.6% fuel utilizations. The results indicate that similar enrichment dynamics apply to both bleed and purge modes.The configuration employed a membrane dryer to circumvent the 60 °C limit of commercially available recirculation pumps. The membrane dryer allows heat and humidity extraction from the anode exit gas stream, enabling the adoption of conventional recirculation pumps, minimizing water condensation, and making sampling with on-line gas analysis instruments easier. The results show that anode gas recirculation systems with hydrogen bleed can be implemented in conventional Test stations by resorting to commercially available recirculation pumps. This enables realistic and cost-effective determination of impurity effects for fuel cell system development and new hydrogen fuel standards.
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comparing anode gas recirculation with hydrogen purge and bleed in a novel pemfc Laboratory Test cell configuration
Fuel Cells, 2015Co-Authors: Pauli Koski, Luis C Perez, Jari IhonenAbstract:In automotive-type polymer electrolyte membrane fuel cell (PEMFC) systems, impurities and inert gases accumulate in the anode gas recirculation loop. Therefore, the impurity limits, dictated by the current hydrogen fuel specification (ISO 14687-2:2012), also require quantification with representative fuel cell Test systems applying anode gas recirculation, that enables high fuel utilization rates and accumulation of impurities.We report a novel PEMFC Laboratory Test cell configuration mimicking automotive conditions. This setup enabled comparison of two operation modes, hydrogen bleed and purge, within 84.4%–98.6% fuel utilizations. The results indicate that similar enrichment dynamics apply to both bleed and purge modes.The configuration employed a membrane dryer to circumvent the 60 °C limit of commercially available recirculation pumps. The membrane dryer allows heat and humidity extraction from the anode exit gas stream, enabling the adoption of conventional recirculation pumps, minimizing water condensation, and making sampling with on-line gas analysis instruments easier. The results show that anode gas recirculation systems with hydrogen bleed can be implemented in conventional Test stations by resorting to commercially available recirculation pumps. This enables realistic and cost-effective determination of impurity effects for fuel cell system development and new hydrogen fuel standards.
Luis C Perez - One of the best experts on this subject based on the ideXlab platform.
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comparing anode gas recirculation with hydrogen purge and bleed in a novel pemfc Laboratory Test cell configuration
Fuel Cells, 2015Co-Authors: Pauli Koski, Luis C Perez, Jari IhonenAbstract:In automotive-type polymer electrolyte membrane fuel cell (PEMFC) systems, impurities and inert gases accumulate in the anode gas recirculation loop. Therefore, the impurity limits, dictated by the current hydrogen fuel specification (ISO 14687-2:2012), also require quantification with representative fuel cell Test systems applying anode gas recirculation, that enables high fuel utilization rates and accumulation of impurities.We report a novel PEMFC Laboratory Test cell configuration mimicking automotive conditions. This setup enabled comparison of two operation modes, hydrogen bleed and purge, within 84.4%–98.6% fuel utilizations. The results indicate that similar enrichment dynamics apply to both bleed and purge modes.The configuration employed a membrane dryer to circumvent the 60 °C limit of commercially available recirculation pumps. The membrane dryer allows heat and humidity extraction from the anode exit gas stream, enabling the adoption of conventional recirculation pumps, minimizing water condensation, and making sampling with on-line gas analysis instruments easier. The results show that anode gas recirculation systems with hydrogen bleed can be implemented in conventional Test stations by resorting to commercially available recirculation pumps. This enables realistic and cost-effective determination of impurity effects for fuel cell system development and new hydrogen fuel standards.
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comparing anode gas recirculation with hydrogen purge and bleed in a novel pemfc Laboratory Test cell configuration
Fuel Cells, 2015Co-Authors: Pauli Koski, Luis C Perez, Jari IhonenAbstract:In automotive-type polymer electrolyte membrane fuel cell (PEMFC) systems, impurities and inert gases accumulate in the anode gas recirculation loop. Therefore, the impurity limits, dictated by the current hydrogen fuel specification (ISO 14687-2:2012), also require quantification with representative fuel cell Test systems applying anode gas recirculation, that enables high fuel utilization rates and accumulation of impurities.We report a novel PEMFC Laboratory Test cell configuration mimicking automotive conditions. This setup enabled comparison of two operation modes, hydrogen bleed and purge, within 84.4%–98.6% fuel utilizations. The results indicate that similar enrichment dynamics apply to both bleed and purge modes.The configuration employed a membrane dryer to circumvent the 60 °C limit of commercially available recirculation pumps. The membrane dryer allows heat and humidity extraction from the anode exit gas stream, enabling the adoption of conventional recirculation pumps, minimizing water condensation, and making sampling with on-line gas analysis instruments easier. The results show that anode gas recirculation systems with hydrogen bleed can be implemented in conventional Test stations by resorting to commercially available recirculation pumps. This enables realistic and cost-effective determination of impurity effects for fuel cell system development and new hydrogen fuel standards.
