Spectroscopically Pure Substances

Phase - Change Processes of Pure Substances

Mathematical and Computational Aspects of Solidification of Pure Substances

The aim of the article is to deliver an information on the state of the art in the field of modelling of microstructure growth in a solidifying pure substance with a stress on the phase-field approach. We briefly summarize the physical background of the problem. The phase-field method is then explained and its variants are mentioned. Justification and theoretical results concerning the model eq...

Spectrophotometric Determination of Thiols in Pure Substances and Pharmaceutical Preparations

A spectrophotometric method for determination of mesna (MA), 6-mercaptopurine (MP), 6-thioguanine (TG), and 6-propyl-2-thiouracil (PTU) has been developed. The method was based on the reaction of thiouracils with N,N-dimethyl-p-phenylenediamine (DMPD) in acidic solution in the presence of the Fe3+ ion, an oxidising agent. Absorbance of the obtained coloured products was measured at the correspo...

An accurate General Method to Correlate Saturated Vapor Pressure of Pure Substances

In this study, a generalized equation is presented to calculate vapor pressure of pure substances as a function of reduced temperature, critical pressure, and acentric factor. With the presented model, vapor pressures have been calculated and evaluated with NIST data bank for 70 pure substances for about 14000 data points, and the overall average absolute percentage deviation has been only 0.78...

A Molecular-Based Equation of State for Vapour-liquid Equilibrium of Pure Substances

A semi-empirical equation of state has been studied for modelling vapour-liquid data of pure substances. The specific molecular based equation of state is employed here as basis because of its mathematical simplicity. The semi-empirical extension has been accomplished to real fluids by correlating the density dependence of the attraction term to vapour liquid data of a reference fluid. The resu...