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91.
Ki-Pung Yoo Hun Yong Shin Min Jeong Noh Seong Sik You 《Korean Journal of Chemical Engineering》1997,14(5):341-346
To design a supercritical fluid extraction process for the separation of bioactive substances from natural products, a quantitative
knowledge of phase equilibria between target biosolutes and solvent is necessary. How-ever, mostly no such information is
available in literature to date. Thus in the present study, illustratively the solubility of bioactive coumarin and its various
derivatives (i.e., hydroxy-, methyl-, and methoxy-derivatives) in supercritical CO2 were measured at 308.15–328.15 K and 10–30 MPa. Also, the pure physical properties such as normal boiling point, critical
constants, acentric factor, molar volume and standard vapor pressure for coumarin and its derivatives were estimated. By these
estimated information, the measured solubilities were quantitatively correlated by an approximate lattice equation of state
proposed recently by the present authors. 相似文献
92.
93.
Chul Kwak Stanley I. Sandler Hun-Soo Byun 《Korean Journal of Chemical Engineering》2006,23(6):1016-1022
The correlation of vapor-liquid equilibrium data for high-pressure carbon dioxide systems is of interest in a number of industrial
applications, including supercritical extraction. Here, we consider the correlation of data for 12 binary systems of carbon
dioxide separately with alcohols, with hydrocarbons, and with acetone, benzene, and water. The Wong-Sandler (W-S) and modified
Huron — Vidal first order (MHV1) free energy-based equation of state mixing rules (the W-S and MHV1 models) were used in the
calculations. Both combined equation of state+free energy models generally resulted in good correlations of the experimental
data over wide ranges of temperature and pressure with temperature — independent parameters. However, for the carbon dioxide+water
system, the W-S model produced an 11% average absolute deviation in pressure, while no parameter that resulted in an AAD in
pressure of less than 20% could be found for the MHV1 model. 相似文献
94.
95.
黄格红 《数码设计:surface》2014,(4):171-173
校企共建集多功能校内生产性实习基地,是提升学生专业技能、降低教学实训成本、更好地服务于区域经济的有效方式。面对现有国内高职院校的校内生产性实习过程中遇到诸多问题,通过企业横向项目融入实训教学。营造真实的生产氛围。引进企业生产管理机制。打造双骨千兼职教师等创新建设手段。让校内生产性实训基地运行进入可持续发展的良好模式。 相似文献
96.
E. Gilbert 《臭氧:科学与工程》2002,24(2):75-82
Heterogeneous photocatalytic oxidation processes using titanium oxide as a photocatalyst are widely discussed topics in research for water and waste water treatment. Oxygen fed into the systems is normally used as oxidizing agent. However few investigations exist concerning the use of ozone as an additional oxidant. In this work the influence of ozone on the photocatalytic degradation of organic compounds are described. The results are compared with those by using ozone, UV/O3 and UV/TiO2/O2. The oxidation reactions were performed at pH 3 and 7.
In this research compounds of the different classes were used: glyoxal, pyrrole-2-carboxylic acid, p-toluenesulfonic acid and naphthalene-1,5-disulfonic acid. Depending on the classes of compounds in some cases the elimination rates of the initial compounds is enhanced by using UV/TiO2/O3 compared to UV/O3 or O3 alone. But in all cases greatest DOC elimination is achieved by using UV/TiO2/O3. 相似文献
97.
Mário H.P. Santana 《Electrochimica acta》2006,51(17):3578-3585
A systematic investigation was conducted on the mechanism and electrocatalytic properties of O2 and Cl2 evolution on mixed oxide electrodes of nominal composition: Ti/[Ru(0.3)Ti(0.6)Ce(0.1−x)]O2[Nb2O5](x) (0 ≤ x ≤ 0.1). For the oxygen evolution, a 30 mV Tafel slope is obtained in the presence of CeO2, while in its absence a 40 mV coefficient is observed. The intrinsic electrocatalytic activity is mainly due to electronic factors, as result of the synergism between Ru and Ce oxides. For chlorine evolution, the Tafel slope (30 mV) is independent on oxide composition. The best global electrocatalytic activity for ClER was observed in the absence of Nb2O5 additive. Variation of the voltammetric charge throughout the experiments confirms high CeO2 content compositions are fragile, due mainly to the porosity caused by CeO2 presence. On the other hand, Nb2O5 addition decreases considerably this instability. 相似文献
98.
High-bromide raw water was ozonated or chlorinated with and without hydrogen peroxide to study the effect of the disinfectants on the disinfection by-product (DBP) formation. Less bromate was formed when ozonation was made at the ambient pH of 5.8 as compared to ozonation at pH 7, showing the effectiveness of pH reduction in controlling the bromate formation. When chlorine dose was 1 mg/L instead of 2.3 mg/L, the trihalomethane formation was 50 μg/L instead of >100 μg/L, and the proportional distribution of the trihalomethanes was similar. The use of ozone for this water could provide good results in respect of the DBP formation. 相似文献
99.
罗鑫富 《安徽冶金科技职业学院学报》2010,20(4):25-28
根据烧结生产线上电气故障发生的不同地方和不同类型,探讨运用不同的故障处理方法,以提高及时发现和迅速排除生产线上电气故障效率。 相似文献
100.