Capacity and kinetics of COcapture of NaCOwere studied to determine the mechanism for COsequestration under ambient conditions. Bicarbonate formation of NaCOwas examined by a thermogravimetric analysis（TGA） under va...Capacity and kinetics of COcapture of NaCOwere studied to determine the mechanism for COsequestration under ambient conditions. Bicarbonate formation of NaCOwas examined by a thermogravimetric analysis（TGA） under various COand water vapor concentrations and the accompanying structural changes of NaCOwere demonstrated by X-ray diffraction（XRD）. Morphological variations were observed during the reaction of COcapture through scanning electron microscope（SEM）. Structural changes and morphological variations, which occurred during the course of the reaction, were then connected to the kinetic and exothermic properties of the COcapture process from the XRD and SEM measurements. The results showed that the bicarbonate formation of NaCOhas two different pathways.For higher COand HO concentrations, the bicarbonate formation proceeded effectively. However, for lower COand HO concentrations, the reactions were more complicated. The formation of NaCO·HO from NaCOas the first step, followed by the subsequent formation of NaH（CO）, and then the bicarbonate formation proceeds. To understand such fundamental properties in COcapture of NaCOis very important for utilization of NaCOas a sorbent for COcapture.展开更多
Hem-fir plywood were exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, and one white rot fungus, Trametes versicolor, to investigate the effect of fungal decay on mechanical properties of plywo...Hem-fir plywood were exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, and one white rot fungus, Trametes versicolor, to investigate the effect of fungal decay on mechanical properties of plywood. Results showed that modulus of rupture （MOR） and modulus of elasticity （MOE） of hem-fir plywood declined significantly by inoculating fungi, and weight loss of sample had a modest decrease. The fungi also made a greater effect on MOR than on MOE. Of three fungi, Postia placenta caused a most significant weight loss, and Gloeophyllum trabeum resulted in a largest flexural properties loss. Substantial declines in MOR and MOE of hem-fir plywood were also observed when the plywood samples were stored under wet conditions over 15 weeks, even in the absence of fungal attack.展开更多
In the typhoon adaptive observation based on conditional nonlinear optimal perturbation (CNOP), the ‘on-off’ switch caused by moist physical parameterization in prediction models prevents the conventional adjoint me...In the typhoon adaptive observation based on conditional nonlinear optimal perturbation (CNOP), the ‘on-off’ switch caused by moist physical parameterization in prediction models prevents the conventional adjoint method from providing correct gradient during the optimization process. To address this problem, the capture of CNOP, when the "on-off" switches are included in models, is treated as non-smooth optimization in this study, and the genetic algorithm (GA) is introduced. After detailed algorithm procedures are formulated using an idealized model with parameterization "on-off" switches in the forcing term, the impacts of "on-off" switches on the capture of CNOP are analyzed, and three numerical experiments are conducted to check the effectiveness of GA in capturing CNOP and to analyze the impacts of different initial populations on the optimization result. The result shows that GA is competent for the capture of CNOP in the context of the idealized model with parameterization ‘on-off’ switches in this study. Finally, the advantages and disadvantages of GA in capturing CNOP are analyzed in detail.展开更多
基金supported by a Grant-in-Aid for Scientific Research(C)(Grant No.15K05583)from the Japan Society for the Promotion of Science
文摘Capacity and kinetics of COcapture of NaCOwere studied to determine the mechanism for COsequestration under ambient conditions. Bicarbonate formation of NaCOwas examined by a thermogravimetric analysis（TGA） under various COand water vapor concentrations and the accompanying structural changes of NaCOwere demonstrated by X-ray diffraction（XRD）. Morphological variations were observed during the reaction of COcapture through scanning electron microscope（SEM）. Structural changes and morphological variations, which occurred during the course of the reaction, were then connected to the kinetic and exothermic properties of the COcapture process from the XRD and SEM measurements. The results showed that the bicarbonate formation of NaCOhas two different pathways.For higher COand HO concentrations, the bicarbonate formation proceeded effectively. However, for lower COand HO concentrations, the reactions were more complicated. The formation of NaCO·HO from NaCOas the first step, followed by the subsequent formation of NaH（CO）, and then the bicarbonate formation proceeds. To understand such fundamental properties in COcapture of NaCOis very important for utilization of NaCOas a sorbent for COcapture.
基金This research was supported by Forest Research Labora-tory, Oregon State University
文摘Hem-fir plywood were exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, and one white rot fungus, Trametes versicolor, to investigate the effect of fungal decay on mechanical properties of plywood. Results showed that modulus of rupture （MOR） and modulus of elasticity （MOE） of hem-fir plywood declined significantly by inoculating fungi, and weight loss of sample had a modest decrease. The fungi also made a greater effect on MOR than on MOE. Of three fungi, Postia placenta caused a most significant weight loss, and Gloeophyllum trabeum resulted in a largest flexural properties loss. Substantial declines in MOR and MOE of hem-fir plywood were also observed when the plywood samples were stored under wet conditions over 15 weeks, even in the absence of fungal attack.
基金Application investigation of conditional nonlinear optimal perturbation in typhoon adaptive observation (40830955)
文摘In the typhoon adaptive observation based on conditional nonlinear optimal perturbation (CNOP), the ‘on-off’ switch caused by moist physical parameterization in prediction models prevents the conventional adjoint method from providing correct gradient during the optimization process. To address this problem, the capture of CNOP, when the "on-off" switches are included in models, is treated as non-smooth optimization in this study, and the genetic algorithm (GA) is introduced. After detailed algorithm procedures are formulated using an idealized model with parameterization "on-off" switches in the forcing term, the impacts of "on-off" switches on the capture of CNOP are analyzed, and three numerical experiments are conducted to check the effectiveness of GA in capturing CNOP and to analyze the impacts of different initial populations on the optimization result. The result shows that GA is competent for the capture of CNOP in the context of the idealized model with parameterization ‘on-off’ switches in this study. Finally, the advantages and disadvantages of GA in capturing CNOP are analyzed in detail.
