Development of sustainable construction materials has been the focus of research efforts worldwide in recent years.Concrete is a major construction material;hence,finding alternatives to ordinary Portland cement is of...Development of sustainable construction materials has been the focus of research efforts worldwide in recent years.Concrete is a major construction material;hence,finding alternatives to ordinary Portland cement is of extreme importance due to the high levels of carbon dioxide emissions associated with its manufacturing process.This study investigates the geopolymerization process.Specimens with,two different water/binder weight ratios,0.30 and 0.35,were monitored using acoustic emission.Results show that there is a significant difference in the acquisition data between the two different water/binder weight ratios.In addition,acoustic emission can be used to beneficially monitor and investigate the early geopolymerization process.The acoustic emission data were processed through pattern recognition.Two clusters were identified,assigned to a specific mechanism depending on their characteristics.SEM observations were coincided with pattern recognition findings.展开更多
The adsorption isotherms of phenylalanine from aqueous solution on active carbon and silica gel at varying pH,and the influence of inorganic salt upon the ad rption have been studied (at 25℃).The adsorption amount of...The adsorption isotherms of phenylalanine from aqueous solution on active carbon and silica gel at varying pH,and the influence of inorganic salt upon the ad rption have been studied (at 25℃).The adsorption amount of phcnylalanine on the silica gel is very low due to the strong ad- sorption of water by silica gel.The results on the active carbon show:(1)The adsorption is found to be pH-dependent,within pH 4.1—5.1 it increases with pH,within pH 5.1—11.8 it decreases with pH,at pH 5.1 the adsorption reaches its maximum;(2)The phenylalanine is adsorbed mainly in the form of zwitterion;(3)A certain amount of cations and anions of phenylalanine are also adsorbed with van der Waals interaction;(4)After adding NaCl,the adsorption of phenylalanine increases markedly.展开更多
基金supported by the U.S.Department of Energy Office of Science,Office of Basic Energy Sciences,and Office of Biological and Environmental Research under Award Number DE-SC-00012530.
文摘Development of sustainable construction materials has been the focus of research efforts worldwide in recent years.Concrete is a major construction material;hence,finding alternatives to ordinary Portland cement is of extreme importance due to the high levels of carbon dioxide emissions associated with its manufacturing process.This study investigates the geopolymerization process.Specimens with,two different water/binder weight ratios,0.30 and 0.35,were monitored using acoustic emission.Results show that there is a significant difference in the acquisition data between the two different water/binder weight ratios.In addition,acoustic emission can be used to beneficially monitor and investigate the early geopolymerization process.The acoustic emission data were processed through pattern recognition.Two clusters were identified,assigned to a specific mechanism depending on their characteristics.SEM observations were coincided with pattern recognition findings.
文摘The adsorption isotherms of phenylalanine from aqueous solution on active carbon and silica gel at varying pH,and the influence of inorganic salt upon the ad rption have been studied (at 25℃).The adsorption amount of phcnylalanine on the silica gel is very low due to the strong ad- sorption of water by silica gel.The results on the active carbon show:(1)The adsorption is found to be pH-dependent,within pH 4.1—5.1 it increases with pH,within pH 5.1—11.8 it decreases with pH,at pH 5.1 the adsorption reaches its maximum;(2)The phenylalanine is adsorbed mainly in the form of zwitterion;(3)A certain amount of cations and anions of phenylalanine are also adsorbed with van der Waals interaction;(4)After adding NaCl,the adsorption of phenylalanine increases markedly.
