Use of the NRTL equation for simultaneous correlation of vapour-liquid equilibria and excess enthalpy

The NRTL model has been used to correlate the data for the aqueous alkanolamine systems of (MEA+H₂O), (DEA+H₂O) and (MDEA+H₂O). The model was successfully applied to correlate simultaneously the excess enthalpy, vapour-liquid equilibria, and low temperature activity coefficients. A large database of data was collected for the investigation and it covers a wide range of composition, temperature and pressures. It was found that the form of the binary interaction parameters used by Posey (1996) with a variable non-randomness parameter gave the best results.     

馏出液的酸度对蒸馏-纳氏试剂分光光度法测定氨氮的影响

分析了馏出液的酸度对蒸馏-纳氏试剂分光光度法测定氨氮的影响及其解决办法。若以硼酸为吸收液,需加入氢氧化钠溶液调节馏出液的pH约为10可消除影响。若以盐酸、硫酸和水代替硼酸作为蒸馏吸收液,则无需调节馏出液的酸度即可得到满意的试验结果。     

Empirical correlation equations describing retention data of hydrocarbons on dinonylphatalate and polyethyleneglycol 4000

Summary Relative retention data and Kováts retention indices were measured for several hydrocarbons (mainly for alkylbenzenes) on dinonylphtalate and polyethylenelycol 4000 stationary phase. Correlations were searched between these retention data and the following physical (boiling point, molrefraction, molvolume) and topological (connectiviity index and general index of molecular complexity) properties of solutes. The best fitting equations was choosen among more than 150 equations involving linear, quadratic, exponential, two variables linear and quadratic dependence of retention data and the properties mentioned as well as their inverses.     

A simultaneous correlation of vapour pressures and thermal data: application to 1-alkanols

R∪žička, K. and Majer, V., 1986. A simultaneous correlation of vapour pressures and thermal data: application to 1-alkanols. Fluid Phase Equilibria, 28: 253-264Possibilities of simultaneous correlation of vapour pressures and thermal data (enthalpy of vaporization and difference between heat capacity of idea gas and liquid) are investigated. This approach permits a reliable evaluation of vapour pressures and/or enthalpies of vaporization far below the normal boiling point and can serve also as a consistency test of experimental data. A simple procedure using smoothed input data is proposed which can be implemented in a software of the data bank of thermodynamic properties. The method is demonstrated on a group of eight 1-alkanols.     

The correlation equations describing retention index data on OV-101, OV-275 and PEG 20M.n-alkanes andn-alkynes

Summary The correlation equations between Kovats retention indices ofn-alkenes andn-alkynes, column temperature and number of carbon atoms in molecules of these compounds on OV-101, OV-225 and PEG 20M capillary columns have been calculated. The two variable equationI=A + B · n + C / T give a good fit and are the simplest for practical use.     

大一学生开展基础无机化学专题演讲活动的尝试

如何在现行教学计划中开展好大学一年级基础无机化学的教学,关系到学生对化学学科的学习兴趣、教学效果以及创新人才的培养。尝试在大一基础无机化学课程中开展专题演讲活动,期望可以激发学生的学习兴趣,提高学生获取新知识的能力,锻炼学生的团队精神和演讲表达能力。     

Extension of the electrolyte NRTL and Wilson models for correlation of viscosity of strong electrolyte solutions at different temperatures

The electrolyte NRTL model [C.C. Chen, L.B. Evans, AIChE J. 32 (1986) 444–454] and electrolyte Wilson model [E. Zhao, M. Yu, R.E. Sauvé, M. Khoshkbarchi, Fluid Phase Equilibr. 173 (2000) 161–175] have been extended for the representation of the dynamic viscosity of strong electrolyte solutions. The models are based on Eyring's absolute rate theory and the electrolyte NRTL and Wilson models for calculating the excess Gibbs energy of activation of the viscous flow. The utility of the models is demonstrated with a successful representation of the viscosity of several electrolyte solutions at different temperatures. The results show that, the model is valid for the whole range of salt concentration and it is reliable for correlation of the viscosity of electrolyte solutions at different temperatures by only four adjustable parameters per binary system.     

Insight into the relationship between the Fourier's law of heat conduction and Fick's law over a Riga device: Fourth grade analysis

Mixed convective flow of fourth grade (Non-Newtonian) fluid model by a Riga stretchable plate is addressed. The aim of the current research work is therefore to explain the role of the fourth grade (Non-Newtonian) fluid model in the field of fluid dynamics. Energy and concentration equations are modeled subject to both Fourier's law of heat conduction and Fick's law. Radiation aspects and heat source/sink phenomenon are also accounted. Entropy analysis is discussed through second thermodynamics law. The (OHAM) approach is used to achieve a meaningful solution. Finally, the emerging variables behavior on the velocity, temperature, concentration and entropy rate are discussed graphically. Here, velocity enhances for increasing range of fourth grade variable. Temperature boosts against rising radiation and thermal relaxation variables, but opposite trend is noted for solutal relaxation parameter on concentration.