The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Pijolat Michèle - One of the best experts on this subject based on the ideXlab platform.
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Kinetics of CeO2, surface area reduction in a mixture of HCl, H2O, and O2
Journal of the American Ceramic Society, 2015Co-Authors: Gruy Frédéric, Pijolat MichèleAbstract:Surface area reduction of a cerium dioxide powder is studied at 900 K in a HCl, H2O, and O2 atmosphere. The rate of surface area decrease determined as a function of the surface chloride content and of the partial pressure of hydrogen chloride. It is shown that particle growth occurs due to the surface diffusion of cerium and hydroxyl ions, which results from hygrogen chloride adsorption. Adsorbed chloride ions react to give gaseous Chlorine. The rate-determining step of the process of initial coarsening is hydrogen chloride fixation at the surface of ceriumdioxide particles.
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Kinetics of CeO2 Surface Area Reduction in a Mixture of HCI, H2O, and O2
Journal of the American Ceramic Society, 2015Co-Authors: Gruy Frédéric, Pijolat MichèleAbstract:Surface area reduction of a cerium dioxide powder is studied at 900 K in a HCI, H2O, and O2 atmosphere. The rate of surface area decrease is determined as a function of the surface chloride content and of the partial pressure of hydrogen chloride. It is shown that particle growth occurs due to the surface diffusion of cerium and hydroxyl ions, which results from hydrogen chloride adsorption. Adsorbed chloride ions react to give gaseous Chlorine. The rate-determining step of the process of initial coarsening is hydrogen chloride fixation at the surface of cerium dioxide particles
Gruy Frédéric - One of the best experts on this subject based on the ideXlab platform.
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Kinetics of CeO2, surface area reduction in a mixture of HCl, H2O, and O2
Journal of the American Ceramic Society, 2015Co-Authors: Gruy Frédéric, Pijolat MichèleAbstract:Surface area reduction of a cerium dioxide powder is studied at 900 K in a HCl, H2O, and O2 atmosphere. The rate of surface area decrease determined as a function of the surface chloride content and of the partial pressure of hydrogen chloride. It is shown that particle growth occurs due to the surface diffusion of cerium and hydroxyl ions, which results from hygrogen chloride adsorption. Adsorbed chloride ions react to give gaseous Chlorine. The rate-determining step of the process of initial coarsening is hydrogen chloride fixation at the surface of ceriumdioxide particles.
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Kinetics of CeO2 Surface Area Reduction in a Mixture of HCI, H2O, and O2
Journal of the American Ceramic Society, 2015Co-Authors: Gruy Frédéric, Pijolat MichèleAbstract:Surface area reduction of a cerium dioxide powder is studied at 900 K in a HCI, H2O, and O2 atmosphere. The rate of surface area decrease is determined as a function of the surface chloride content and of the partial pressure of hydrogen chloride. It is shown that particle growth occurs due to the surface diffusion of cerium and hydroxyl ions, which results from hydrogen chloride adsorption. Adsorbed chloride ions react to give gaseous Chlorine. The rate-determining step of the process of initial coarsening is hydrogen chloride fixation at the surface of cerium dioxide particles
James A Goodrich - One of the best experts on this subject based on the ideXlab platform.
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Real-time contaminant detection and classification in a drinking water pipe using conventional water quality sensors: Techniques and experimental results
Journal of Environmental Management, 2009Co-Authors: Y. Jeffrey Yang, Roy C. Haught, James A GoodrichAbstract:Accurate detection and identification of natural or intentional contamination events in a drinking water pipe is critical to drinking water supply security and health risk management. To use conventional water quality sensors for the purpose, we have explored a real-time event adaptive detection, identification and warning (READiw) methodology and examined it using pilot-scale pipe flow experiments of 11 chemical and biological contaminants each at three concentration levels. The tested contaminants include pesticide and herbicides (aldicarb, glyphosate and dicamba), alkaloids (nicotine and colchicine), E. coli in terrific broth, biological growth media (nutrient broth, terrific broth, tryptic soy broth), and inorganic chemical compounds (mercuric chloride and potassium ferricyanide). First, through adaptive transformation of the sensor outputs, contaminant signals were enhanced and background noise was reduced in time-series plots leading to detection and identification of all simulated contamination events. The improved sensor detection threshold was 0.1% of the background for pH and oxidation-reduction potential (ORP), 0.9% for free Chlorine, 1.6% for total Chlorine, and 0.9% for chloride. Second, the relative changes calculated from adaptively transformed residual Chlorine measurements were quantitatively related to contaminant-Chlorine reactivity in drinking water. We have shown that based on these kinetic and chemical differences, the tested contaminants were distinguishable in forensic discrimination diagrams made of adaptively transformed sensor measurements.
A. Savaş Koparal - One of the best experts on this subject based on the ideXlab platform.
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Studies on electrochemical disinfectant production using anodes containing RuO_2
Journal of Applied Electrochemistry, 2005Co-Authors: M. E. H. Bergmann, A. Savaş KoparalAbstract:The present work contains results for artificial water electrolysis in discontinuous operation using laboratory reactors without separators. Rotating anodes with mixed oxide coatings containing IrO_2/RuO_2 were used. The experimental parameters were the chloride concentration, current density, rotation rate, cathode material, pH and water composition. Active and total Chlorine concentrations and current efficiencies were obtained. It was shown that even for very low chloride concentrations, Chlorine formation occurs, but side effects and side reactions significantly lower the efficiency in this case. Nitrite and ammonia formation was found to reduce the efficiency of Chlorine formation. Partial polarization curves were obtained in kinetic experiments using solutions containing chloride and sulphate ions.
Y. Jeffrey Yang - One of the best experts on this subject based on the ideXlab platform.
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Real-time contaminant detection and classification in a drinking water pipe using conventional water quality sensors: Techniques and experimental results
Journal of Environmental Management, 2009Co-Authors: Y. Jeffrey Yang, Roy C. Haught, James A GoodrichAbstract:Accurate detection and identification of natural or intentional contamination events in a drinking water pipe is critical to drinking water supply security and health risk management. To use conventional water quality sensors for the purpose, we have explored a real-time event adaptive detection, identification and warning (READiw) methodology and examined it using pilot-scale pipe flow experiments of 11 chemical and biological contaminants each at three concentration levels. The tested contaminants include pesticide and herbicides (aldicarb, glyphosate and dicamba), alkaloids (nicotine and colchicine), E. coli in terrific broth, biological growth media (nutrient broth, terrific broth, tryptic soy broth), and inorganic chemical compounds (mercuric chloride and potassium ferricyanide). First, through adaptive transformation of the sensor outputs, contaminant signals were enhanced and background noise was reduced in time-series plots leading to detection and identification of all simulated contamination events. The improved sensor detection threshold was 0.1% of the background for pH and oxidation-reduction potential (ORP), 0.9% for free Chlorine, 1.6% for total Chlorine, and 0.9% for chloride. Second, the relative changes calculated from adaptively transformed residual Chlorine measurements were quantitatively related to contaminant-Chlorine reactivity in drinking water. We have shown that based on these kinetic and chemical differences, the tested contaminants were distinguishable in forensic discrimination diagrams made of adaptively transformed sensor measurements.