A stripping batch distillation column is preferred when the amount of the light component in the feed is small and the products are to be recovered at high purity. The operation modes of a batch stripping are believed...A stripping batch distillation column is preferred when the amount of the light component in the feed is small and the products are to be recovered at high purity. The operation modes of a batch stripping are believed to be the same as those of a rectifier. However, the control system of a stripper is different. In this paper, we explore three different control methods with Hysys (Hyprotech Ltd. 1997) for a batch stripper. The main difference is the control scheme for reboiler liquid level: (a) controlled by reflux flow; (b) controlled by reboiler heat duty; (c) controlled by bottom product flow. The main characteristics of operating a batch stripper with different control scheme are presented in this paper. Guidelines are provided for the startup of a batch stripper, the effects of somecontrol tuning parameters on the column performance are discussed.展开更多
OBJECTIVE: To study the antiviral activities of clemastanin B(CB), epigoitrin, phenylpropanoids portion(PEP) and the mixture of phenylpropanoids, alkaloids and organic acid fractions(PEP+ALK+OA)from Banlangen(Radix Is...OBJECTIVE: To study the antiviral activities of clemastanin B(CB), epigoitrin, phenylpropanoids portion(PEP) and the mixture of phenylpropanoids, alkaloids and organic acid fractions(PEP+ALK+OA)from Banlangen(Radix Isatidis).METHODS: The experiment consisted of four parts:therapeutic action, prophylaxsis action, inhibition of virus attachment, and direct virucidal action. Cytopathic effect(CPE) and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) were used to assess antiviral activity.RESULTS: CB, epigoitrin, PEP and PEP + ALK + OA fractions from Banlangen(Radix Isatidis) extract significantly increased the viability of MDCK cells pre-infected with the virus compared with the virus control group in all the dilutions(P < 0.01). Pretreated with either pure compounds or chemical frac-tions of Banlangen(Radix Isatidis) extract in all the dilutions significantly improved the viability of MDCK cells(P < 0.01). The inhibition of virus absorption to the host cells by CB, epigoitrin and PEP was in a dose dependent manner.CONCLUSION: CB, epigoitrin, PEP and PEP+ALK+OA exert their anti-influenza activity by inhibiting the virus multiplication, prophylaxsis and blocking the virus attachment. The primary mode of action of PEP and PEP + ALK + OA is the inhibition of virus replication. The inhibitory effects on virus attachment and multiplication are the main modes for epigoitrin.展开更多
基金Supported by CONICET (Consejo Nacional de Investigaciones Cientificas y Tecnicas, Argentina) (No. 778) and the Scientific Research Foundation of the State Education Ministry for Returned Overseas Chinese Scholar.
文摘A stripping batch distillation column is preferred when the amount of the light component in the feed is small and the products are to be recovered at high purity. The operation modes of a batch stripping are believed to be the same as those of a rectifier. However, the control system of a stripper is different. In this paper, we explore three different control methods with Hysys (Hyprotech Ltd. 1997) for a batch stripper. The main difference is the control scheme for reboiler liquid level: (a) controlled by reflux flow; (b) controlled by reboiler heat duty; (c) controlled by bottom product flow. The main characteristics of operating a batch stripper with different control scheme are presented in this paper. Guidelines are provided for the startup of a batch stripper, the effects of somecontrol tuning parameters on the column performance are discussed.
基金the National Natural Science Foundation of China Grant(No.81073023)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.ysxk-2010)2013 Program sponsored for scientific innovation research of college graduate in Jiangsu province(No.CXZZ13_0631)
文摘OBJECTIVE: To study the antiviral activities of clemastanin B(CB), epigoitrin, phenylpropanoids portion(PEP) and the mixture of phenylpropanoids, alkaloids and organic acid fractions(PEP+ALK+OA)from Banlangen(Radix Isatidis).METHODS: The experiment consisted of four parts:therapeutic action, prophylaxsis action, inhibition of virus attachment, and direct virucidal action. Cytopathic effect(CPE) and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) were used to assess antiviral activity.RESULTS: CB, epigoitrin, PEP and PEP + ALK + OA fractions from Banlangen(Radix Isatidis) extract significantly increased the viability of MDCK cells pre-infected with the virus compared with the virus control group in all the dilutions(P < 0.01). Pretreated with either pure compounds or chemical frac-tions of Banlangen(Radix Isatidis) extract in all the dilutions significantly improved the viability of MDCK cells(P < 0.01). The inhibition of virus absorption to the host cells by CB, epigoitrin and PEP was in a dose dependent manner.CONCLUSION: CB, epigoitrin, PEP and PEP+ALK+OA exert their anti-influenza activity by inhibiting the virus multiplication, prophylaxsis and blocking the virus attachment. The primary mode of action of PEP and PEP + ALK + OA is the inhibition of virus replication. The inhibitory effects on virus attachment and multiplication are the main modes for epigoitrin.
