Material and heat transfer rate in the gas-lquid system

In this paper substance transfer rate in the multistage system was investigated. Substance transfer between liquid and gas phases in a distillation packed column with packing was examined. Substance and heat transfer rate were examined and substance transfer coefficients were determined. Efficiency of substance transfer were examined by height of transfer units and volumetric substance transfer coefficients. Based on derived mathematical model the total height of transfer units and individual height of transfer units for the liquid and gas phases were determined. The investigation was performed by computer simulation and experiments. Several correlation models for height of transfer units and substance transfer coefficients were studied

Plasma and erythrocyte phospholipid fatty acids composition in serbian hemodialyzed patients

Dyslipidemia is one of the possible risk factors for advanced atherosclerosis in patients with chronic renal failure. Abnormal phospholipid metabolism may play an important role in the progression of atherosclerosis in patients with renal failure. The aim of this study was to determine specific characteristics of plasma and erythrocyte phospholipid content and fatty acid composition in 37 patients with chronic renal failure on hemodialysis (HD). The results were compared with the characteristics of healthy subjects. Briefly, plasma triglyceride (p lt 0.001), total cholesterol (p lt 0.05), and total phospholipids (p lt 0.01) levels were significantly higher and HDL-cholesterol level significantly lower (p lt 0.01) in HD patients. Plasma phosphatidylcholine and phosphatidylethanolamine concentration were significantly higher (p lt 0.001) in HD patients. The plasma phospholipid fatty acids composition indicated significantly (p lt 0.01) higher level of oleic (18:1 n-9) and lower levels of eicopentaenoic (20:5 n-3 EPA) and docosahexaenoic (22:6 n-3 DHA) acids (p lt 0.05). However, in HD patients, the relative concentration of plasma phospholipid n-6 polyunsaturated fatty acid (PUFA) was significantly lower (p lt 0.05). The fatty acid composition of erythrocyte phospholipid in HD patients was modified with EPA and DHA levels significantly lowered (p lt 0.05). Our results demonstrate an abnormal phospholipid metabolism and deficiency of n-3 PUFA in plasma and erythrocyte phospholipids in hemodialyzed patients

Modelling of the substance transfer in the gas-liquid system with chemical reaction

In this paper substance transfer phenomena in the multistage reactive system were investigated.Substance transfer between liquid and gas phases in a distillation packed column with reactionesterification was examined. Efficiency of substance transfer were examined by HTU-Height of transferunits and volumetric substance transfer coefficients. The esterification reaction of the ethanol andacetic acid was examined. Based on derived mathematical model the total height of transfer units andindividual height of transfer units for the liquid and gas phases were determined. The investigation wasperformed by computer simulation and experiments. Several correlation models for HTU/NTU andsubstance transfer coefficients were studied. The correlations for component transfer were derived inquaternary systems ethanol-ethyl acetate-acetic acid -water