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This work presents a new formula to calculate the surface tension of ketones. As a first step, an analysis of the available data of the experimental surface tension data for ketones was made. Experimental data were collected for the following pure fluids: acetone, 2-butanone, 2-pentanone, 3-pentanone, 2-hexanone, 3-heptanone, 4-heptanone, 2-octanone, and 6-undecanone. The data were then regressed with the most reliable semi-empirical correlation methods in the literature based on the corresponding states theory. The final equation proposed is very simple and gives noticeable improvement with respect to existing equations.

This work presents a wide literature survey of the available data of the experimental thermal conductivity data of organic liquids. The experimental data were collected for 136 compounds belonging to the following families: refrigerants, alkanes, alkenes, aromatics, cycloalkanes, cycloalkenes, ethers, esters, ketones, carboxylic acids, and alcohols. The experimental data were regressed with the most reliable semi-empirical correlating methods existing in the literature and a reliable set of 4,584 experimental data was finally selected. The influence of several physical parameters on the thermal conductivity calculation is discussed and a new equation to represent the thermal conductivity of organic liquids at atmospheric pressure for temperatures below normal boiling point and at saturation for temperatures above the normal boiling point is presented. To minimize the deviation between the predictions and the experimental data and to find the optimal coefficients for the proposed equation, a statistical analysis was performed. The resulting equation is simple and is able to predict the thermal conductivities with low deviations for the major part of the collected data for the studied families.

This study presents a new formula for the surface tension prediction of alkenes. As a first step, an analysis of the available data of the experimental surface tension data for alkenes was performed. The experimental data were collected, after a careful literature survey, for the following pure fluids: propene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-tetradecene, and 1-pentadecene. Then, the experimental data were regressed with the most reliable semi-empirical correlating methods based on the corresponding state theory existing in the literature. As a final step, an analysis of the available data of the experimental surface tension data for alkenes was performed starting from the two recently proposed equations for the prediction of the surface tension of refrigerants based on the corresponding states principle. To minimize the deviation between the predicted data and the experimental data and to find the optimal equation coefficients for experimental data regression, a (μ + λ)-evolution strategy was adopted. The analysis showed that the equation that gave the best results for the prediction of the surface tension of alkenes was the one with a very limited number of parameters. The finally proposed equation is very simple and gives a noticeable improvement with respect to the existing equations. It is based on the corresponding state principle, containing the acentric factor, the critical temperature, and pressure.

Triple point data are important in the refrigerating industry, defining the lowest temperature limit at which a refrigerant may circulate in a fluid state. For several refrigerants, triple point data present in the literature are extremely scarce or inaccurate. A recently developed Solid–Liquid Equilibria (SLE) apparatus was used to measure the triple point temperature of 16 of the most widely applied alternative refrigerants, namely three methane derivatives (fluoromethane, R41; difluoromethane, R32; trifluoromethane, R23), four ethane derivatives (pentafluoroethane, R125; 1,1,1,2-tetrafluoroethane, R134a; 1,1,1-trifluoroethane, R143a; 1,1-difluoroethane, R152a), five propane derivatives [1,1,1,2,3,3,3-heptafluoropropane, R227ea; 1,1,2,3,3,3-hexafluoropropane, R236ea; 1,1,1,3,3-Pentafluoropropane, R245fa; 1,1,2,2,3-pentafluoropropane, R245ca; 1,1,1,3,3,3-hexafluoropropane, R236fa), and four hydrofluoro-olefines (2,3,3,3-tetrafluoroprop-1-ene, R1234yf; trans-1,3,3,3 tetrafluoropropene, R1234ze(E); 3,3,3-trifluoropropene, R1243zf; 1,2,3,3,3-pentafluoropropene, 1225ye(Z)]. The experimental setup, that was recently adopted for the SLE estimation of binary systems containing carbon dioxide (J Therm Anal Calorim 105:489–493, 2011), comprises a measuring cell and a system for drawing the liquid nitrogen directly from its insulated tank with the aid of compressed air: the carrier fluid circulating in the circuit is thus the refrigerant itself. The measurements were performed both in the heating and in the cooling mode. In order to confirm the functional efficiency and fine adjustment of the apparatus, the already available triple point literature data for carbon dioxide, dimethyl ether, and nitrous oxide were also compared with the ones measured by the present setup, confirming the validity of the setup. The measured triple point data for the refrigerants revealed generally good agreement with the literature, excepting a few fluids that revealed some discrepancies.