The flow of pulp fiber suspensions with a consistency below 5% through a pump falls into the turbulent region. The 2-phase 3D turbulent flow of the mixture is simulated in the hydraulic components composed by suction ...The flow of pulp fiber suspensions with a consistency below 5% through a pump falls into the turbulent region. The 2-phase 3D turbulent flow of the mixture is simulated in the hydraulic components composed by suction chamber, front board, semi-impeller and volute casing for the first time. The pseudo-fluid model and the k-ε turbulent model are modified. Phase coupled SIMPLE algorithm is applied to make pressure-velocity correction equation. Based on the results of the numerical simulation, the distribution of velocity, pressure and density of liquid and particle phase are compared and analyzed. The flow analysis in the tip between front board and impeller is emphasized, which reflects the advantage of semi-open impeller when it transports 2-phase medium. This calculation result will be helpful for the design of pump impeller and the establishment of design method of centrifugal stock pump.展开更多
The purpose of this study was to establish a method for determining the free concentration of ceftriaxone based on hollow fiber centrifugal ultrafiltration(HFCF-UF)technology in combination with high-performance liqui...The purpose of this study was to establish a method for determining the free concentration of ceftriaxone based on hollow fiber centrifugal ultrafiltration(HFCF-UF)technology in combination with high-performance liquid chromatography(HPLC)for free pharmacokinetic studies and the prediction of ceftriaxone concentrations in lung tissue.This method only required centrifugation for a short time,and the filtrate could be injected directly for HPLC analysis without further treatment.The specificity,linearity,precision and stability of this method were validated for quantification of free ceftriaxone.Under the optimized conditions,the absolute recoveries were more than 92.5%.The intraday and interday precision RSDs were less than 3.6%.Additionally,nonspecific adsorption(NSB)between the analyte and the ultrafiltration membrane was considered.This method was successfully applied to the analysis of the free ceftriaxone concentration in rat plasma and lung tissue.The free ceftriaxone concentration of lung tissue could be predicted by using the linear formula Cfl=Cfp(0.342 x–0.0129)(x:time).This method also provides a reliable alternative for accurate monitoring of the free ceftriaxone concentration in therapeutic drug monitoring(TDM).展开更多
基金This project is supported by Provincial Natural Science Foundation of Education Department of Jiangsu(No.02kjd470001).
文摘The flow of pulp fiber suspensions with a consistency below 5% through a pump falls into the turbulent region. The 2-phase 3D turbulent flow of the mixture is simulated in the hydraulic components composed by suction chamber, front board, semi-impeller and volute casing for the first time. The pseudo-fluid model and the k-ε turbulent model are modified. Phase coupled SIMPLE algorithm is applied to make pressure-velocity correction equation. Based on the results of the numerical simulation, the distribution of velocity, pressure and density of liquid and particle phase are compared and analyzed. The flow analysis in the tip between front board and impeller is emphasized, which reflects the advantage of semi-open impeller when it transports 2-phase medium. This calculation result will be helpful for the design of pump impeller and the establishment of design method of centrifugal stock pump.
文摘The purpose of this study was to establish a method for determining the free concentration of ceftriaxone based on hollow fiber centrifugal ultrafiltration(HFCF-UF)technology in combination with high-performance liquid chromatography(HPLC)for free pharmacokinetic studies and the prediction of ceftriaxone concentrations in lung tissue.This method only required centrifugation for a short time,and the filtrate could be injected directly for HPLC analysis without further treatment.The specificity,linearity,precision and stability of this method were validated for quantification of free ceftriaxone.Under the optimized conditions,the absolute recoveries were more than 92.5%.The intraday and interday precision RSDs were less than 3.6%.Additionally,nonspecific adsorption(NSB)between the analyte and the ultrafiltration membrane was considered.This method was successfully applied to the analysis of the free ceftriaxone concentration in rat plasma and lung tissue.The free ceftriaxone concentration of lung tissue could be predicted by using the linear formula Cfl=Cfp(0.342 x–0.0129)(x:time).This method also provides a reliable alternative for accurate monitoring of the free ceftriaxone concentration in therapeutic drug monitoring(TDM).
