The stoichiometric ratios and related regimes, which can promote anti-flooding of polymer electrolyte membrane fuel cell （PEMFC） with in-plate adverse-flow flow-field （IPAF）, were investigated. Two flow combinatio...The stoichiometric ratios and related regimes, which can promote anti-flooding of polymer electrolyte membrane fuel cell （PEMFC） with in-plate adverse-flow flow-field （IPAF）, were investigated. Two flow combinations, which are the simple and complex adverse-flow between plates （ABP） that can be realized by IPAF, were employed. Constant stoichiometric ratios examination indicates that the complex ABP could improve anti-flooding of PEMFC better in the medium （greater than 200 mA/cm2 and less than 1 000 mA/cm2） and high （greater than 1 000 mA/cm2） current densities than the simple ABP. More stoichiometric ratios were introduced to find the cathode critical stoichiometry. Under the condition of cathode critical stoichiometry, the maximal local relative humidity of both electrodes of complex ABP is equal to 100% and below while the anti-flooding of the cathode of simple ABP is not satisfactory in the medium and high current densities. Further study shows that the mechanism of fuel cell, which is the imerdependence between the electrodes effect, can make significant contribution to anti-flooding.展开更多
Polyurethane is a versatile plastic with several industrial applications in the modern life, but it is considered as a very recalcitrant material. Biodegradation of this plastic has been poorly explored, and most of t...Polyurethane is a versatile plastic with several industrial applications in the modern life, but it is considered as a very recalcitrant material. Biodegradation of this plastic has been poorly explored, and most of the studies that have been published focus on bacterial enzymes. In this work, some fungi with the capacity of growing with polyurethane foam as nutrient source were isolated from sands contaminated with this plastic and from DIA/UAdeC collection, testing their ability to grow on polyurethane as sole carbon and nitrogen sources and their enzymatic activities were determined in specific media as well as their invasion capacity on polyurethane agar plates. 22 fungal strains demonstrated their capacity of growing on polyurethane. Among the enzymatic activities evaluate, the most common was the urease activity (95% of the strains).Protease, esterase and laccase activities were present in 86%, 50% and 36% respectively. The great ability of the isolated fungal strains to use polyurethane foam as nutrient opens an important opportunity to study at detail the biodegradation of this plastic, with clear implications in cell biology and environmental technology.展开更多
基金Project(20976095) supported by the National Natural Science Foundation of ChinaProject(2012CB215500) supported by the National Basic Research Program of China+1 种基金Project(20090002110074) supported by the Specialized Research Fund for the Doctoral Program of Higher Education, ChinaProjects(2012AA1106012, 2012AA053402) supported by the National Hi-tech Research and Development Program of China
文摘The stoichiometric ratios and related regimes, which can promote anti-flooding of polymer electrolyte membrane fuel cell （PEMFC） with in-plate adverse-flow flow-field （IPAF）, were investigated. Two flow combinations, which are the simple and complex adverse-flow between plates （ABP） that can be realized by IPAF, were employed. Constant stoichiometric ratios examination indicates that the complex ABP could improve anti-flooding of PEMFC better in the medium （greater than 200 mA/cm2 and less than 1 000 mA/cm2） and high （greater than 1 000 mA/cm2） current densities than the simple ABP. More stoichiometric ratios were introduced to find the cathode critical stoichiometry. Under the condition of cathode critical stoichiometry, the maximal local relative humidity of both electrodes of complex ABP is equal to 100% and below while the anti-flooding of the cathode of simple ABP is not satisfactory in the medium and high current densities. Further study shows that the mechanism of fuel cell, which is the imerdependence between the electrodes effect, can make significant contribution to anti-flooding.
基金CISEF for fungal strains and Consejo Nacional de Ciencia y Tecnología(CONACYT)for the student grant(258623/221603).
文摘Polyurethane is a versatile plastic with several industrial applications in the modern life, but it is considered as a very recalcitrant material. Biodegradation of this plastic has been poorly explored, and most of the studies that have been published focus on bacterial enzymes. In this work, some fungi with the capacity of growing with polyurethane foam as nutrient source were isolated from sands contaminated with this plastic and from DIA/UAdeC collection, testing their ability to grow on polyurethane as sole carbon and nitrogen sources and their enzymatic activities were determined in specific media as well as their invasion capacity on polyurethane agar plates. 22 fungal strains demonstrated their capacity of growing on polyurethane. Among the enzymatic activities evaluate, the most common was the urease activity (95% of the strains).Protease, esterase and laccase activities were present in 86%, 50% and 36% respectively. The great ability of the isolated fungal strains to use polyurethane foam as nutrient opens an important opportunity to study at detail the biodegradation of this plastic, with clear implications in cell biology and environmental technology.
