We adopted a notch method to study the influence of crack width （macro level） on chloride transport and binding of cracked concrete under a non-steady state migration test. The results show that migration coefficien...We adopted a notch method to study the influence of crack width （macro level） on chloride transport and binding of cracked concrete under a non-steady state migration test. The results show that migration coefficient of cracked concrete increases with increasing crack width up to a critical value （0.43 mm）, for the whole concrete or the area close to crack; the increase of migration coefficient could be independent from crack parameter when a critical crack width is reached. For chloride binding, Langmuir isotherms of cracked concrete samples exhibit the similar decreasing trend as crack width increases from 0.27 to 1.96 mm. The increased current value could be responsible for the trend based on the hypothesis of electric force.展开更多
As the environmental load has recently increased, the use of sintered stainless steel for automobile parts is increasing to help weight reducing, high performance and external exposure. Although the low priced pre-mix...As the environmental load has recently increased, the use of sintered stainless steel for automobile parts is increasing to help weight reducing, high performance and external exposure. Although the low priced pre-mixed sintered stainless steel powder parts are used instead of the high priced pre-alloyed powder parts, there have been problems of poor corrosion resistance and high price because the parts are sintered at low temperature due to the change of final part size. This paper describes the alloying process of producing parts having high hardness and corrosion resistance through expanded high concentration chromium on the surface only of sintered steel, which is relatively easier to sinter, using the pack-chromizing technology to improve hardness and corrosion resistance to solve the problem. Notable is the coating where the activated-chromium formed during the pack-chromizing process remains in the coating layer can lower the friction coefficient of the coated layer to up to 0.1. On the one hand, when the hydrocarbon gas was injected so as to promote the chromium-iron mixed carbide formed, the friction coefficient is increased to 0.4 with high hardness values. The thickness of the chromium alloying layer on the specimen can vary at the same temperature and same phase of the coating layer depending on which chromium resource materials (i.e. chromium or chromium-iron mixed powder) is used.展开更多
Knowledge of phosphorus(P)sorption dynamics across different soil types could direct agronomic and environmental management of P.The objective of this study was to predict P isotherm parameters for a national soil pop...Knowledge of phosphorus(P)sorption dynamics across different soil types could direct agronomic and environmental management of P.The objective of this study was to predict P isotherm parameters for a national soil population using data of routine laboratory tests.Langmuir and Freundlich sorption parameters were calculated from two different ranges(0-25 and 0-50 mg P L^(-1))using an archive of representative agricultural soil types from Ireland.Multiple linear regression(MLR)identified labile forms of aluminium(Al)and iron(Fe),organic matter(OM),cation exchange capacity(CEC),and clay as significant drivers.Langmuir and Freundlich sorption capacities,Freundlich affinity constant,and Langmuir buffer capacity were predicted reliably,with R^(2) of independent validation>0.9.Sorption isotherm parameters were predicted from P sorbed at a single concentration of 50 mg P L^(-1)(S_(50)).An MLR prediction of P sorption maximum in the 0-50 mg P L-1 range was achieved,to an accurate standard,using S_(50),OM,and Mehlich-3 Fe(R^(2) of independent calibration and validation being 0.91 and 0.95,respectively).Using Giles’four shapes of isotherms(C,L,H,and S),L non-strict-and C-shaped isotherm curves accounted for 64% and 27% of the soils,respectively.Hierarchical clustering identified a separation of isotherm curves influenced by two ranges of Mehlich-3 Al.Soils with a low range of Mehlich-3 Al(2.5-698 mg kg^(-1))had no incidence of rapid sorption(C shape).Single point indices,Al,or available soil data make the regression approach a feasible way of predicting Langmuir parameters that could be included with standard agronomic soil P testing.展开更多
基金Funded by China Scholarship Council,the Special Research Fund(BOF)of Ghent UniversityNational Natural Science Foundation of China(No.51178363)
文摘We adopted a notch method to study the influence of crack width （macro level） on chloride transport and binding of cracked concrete under a non-steady state migration test. The results show that migration coefficient of cracked concrete increases with increasing crack width up to a critical value （0.43 mm）, for the whole concrete or the area close to crack; the increase of migration coefficient could be independent from crack parameter when a critical crack width is reached. For chloride binding, Langmuir isotherms of cracked concrete samples exhibit the similar decreasing trend as crack width increases from 0.27 to 1.96 mm. The increased current value could be responsible for the trend based on the hypothesis of electric force.
文摘As the environmental load has recently increased, the use of sintered stainless steel for automobile parts is increasing to help weight reducing, high performance and external exposure. Although the low priced pre-mixed sintered stainless steel powder parts are used instead of the high priced pre-alloyed powder parts, there have been problems of poor corrosion resistance and high price because the parts are sintered at low temperature due to the change of final part size. This paper describes the alloying process of producing parts having high hardness and corrosion resistance through expanded high concentration chromium on the surface only of sintered steel, which is relatively easier to sinter, using the pack-chromizing technology to improve hardness and corrosion resistance to solve the problem. Notable is the coating where the activated-chromium formed during the pack-chromizing process remains in the coating layer can lower the friction coefficient of the coated layer to up to 0.1. On the one hand, when the hydrocarbon gas was injected so as to promote the chromium-iron mixed carbide formed, the friction coefficient is increased to 0.4 with high hardness values. The thickness of the chromium alloying layer on the specimen can vary at the same temperature and same phase of the coating layer depending on which chromium resource materials (i.e. chromium or chromium-iron mixed powder) is used.
基金funded by the Teagasc Walsh Fellowship Fund of Ireland(No.RMIS 6502)。
文摘Knowledge of phosphorus(P)sorption dynamics across different soil types could direct agronomic and environmental management of P.The objective of this study was to predict P isotherm parameters for a national soil population using data of routine laboratory tests.Langmuir and Freundlich sorption parameters were calculated from two different ranges(0-25 and 0-50 mg P L^(-1))using an archive of representative agricultural soil types from Ireland.Multiple linear regression(MLR)identified labile forms of aluminium(Al)and iron(Fe),organic matter(OM),cation exchange capacity(CEC),and clay as significant drivers.Langmuir and Freundlich sorption capacities,Freundlich affinity constant,and Langmuir buffer capacity were predicted reliably,with R^(2) of independent validation>0.9.Sorption isotherm parameters were predicted from P sorbed at a single concentration of 50 mg P L^(-1)(S_(50)).An MLR prediction of P sorption maximum in the 0-50 mg P L-1 range was achieved,to an accurate standard,using S_(50),OM,and Mehlich-3 Fe(R^(2) of independent calibration and validation being 0.91 and 0.95,respectively).Using Giles’four shapes of isotherms(C,L,H,and S),L non-strict-and C-shaped isotherm curves accounted for 64% and 27% of the soils,respectively.Hierarchical clustering identified a separation of isotherm curves influenced by two ranges of Mehlich-3 Al.Soils with a low range of Mehlich-3 Al(2.5-698 mg kg^(-1))had no incidence of rapid sorption(C shape).Single point indices,Al,or available soil data make the regression approach a feasible way of predicting Langmuir parameters that could be included with standard agronomic soil P testing.
