The refinement of unsaturated fatty acids (UFA) from Hippophae rhamnoides L. seed oil was carried out by molecular distillation (MD) using response surface methodology (RSM). A central composite rotate design was used in order to optimize the experimental parameters: distilling temperature and feed flow. The optimal MD conditions were determined and the quadratic response surfaces were drawn from the mathematical models. The results suggested that the distilling temperature and feed flow significantly affected both the UFA content and oil yield in the two models. The optimum conditions for refining UFA were: distilling temperature 107.5 °C and feed flow 1 ml min−1. Optimal values predicted by RSM for the UFA content and oil yield were 82.38% and 62.59%, respectively. Close agreement between experimental and predicted values was obtained.
Authors:M. Zheng, L. Zhang, H. P. Teng, J. Hu, and M. L. Hu
In the present paper, CFD simulation is used to perform the numerical calculation of behaviours of multi-blade drag typed VAWT. The sliding grid technology, FLUENT software and PISO algorithm are involved. By taking wind power efficiency Cp as the goal function, the optimal situations of multi-blade drag typed VAWT with 4 and 6 blades are conducted by CFD simulation. In this investigation, the variable parameters include the rotation rate of wind-mill ω, the blade installation angle θ and the blade width d. The results show that: the optimal working conditions for the 4-blade wind mill at the inlet wind speed 8 m/s are ω = 18 r/ min, θ = 28°, and d = 0.83 m, which induces an optimal wind power efficiency rate Cp = 27.127%; the optimal working conditions for the 6-blade wind mill at the inlet wind speed 8 m/s are ω = 18 r/min, θ = 27°, and d = 0.67 m, which leads to an optimal wind power efficiency rate Cp = 30.404%.
Authors:W.M. Du, F.H. Wang, H.Y. Zhang, B.Z. Jiang, X.Y. Chen, W. Zhang, Y. Xie, and Z.T. Sheng
Present research on prebiotics focuses on either polysaccharides or polyphenols. This study compared the individual and combined impact of polysaccharide, quercetin, and gallic acid (GA) treatment on three human faecal strains. In vitro pure culturing and correlation analysis confirmed that the growth of both beneficial microbe B. longum subsp. longum (0.695, 0.205: R2, slope, respectively) and pathogenic C. perfringens (0.712, 0.085: R2, slope, respectively) increased due to polysaccharide treatment, and only GA treatment would inhibit C. perfringens (0.789, –0.165: R2, slope, respectively) growth. In vivo studies also revealed that genome copies of Bifidobacterium increased and C. perfringens decreased in the faeces, when a blend of the three nutrients rather than single polysaccharide or polyphenols were fed to rats. These data suggested that combined prebiotic treatment improved human faecal strain composition better than single treatment.