Résumé: In a previous publication [A. Abbaci, H.R. van den Berg, E. Sakonidou, J.V. Sengers, Int. J. Thermophys. 13, 1043 (1992)], a study of ethane-carbon dioxide mixture critical locus as a function of the mole fraction was presented in order to show the evidence of an abnormal behavior in the critical density curve. An update on the evaluation of the critical parameters of this same mixture was published by [J.V. Sengers, G.X. Jin, Int. J. Thermophys. 28, 1181 (2007)]. In this work, we generalize the study to the critical loci of five selected azeotropic mixtures of perfluoromethylcyclohexane-isomeric hexane systems that have been correlated using simple polynomials. It is generally assumed that an azeotropic mixture is a synonym of a peculiar behavior of the critical density of this mixture as a function of the mole fraction. The purpose of this correlation is to show that this is not the case. Finally, we show the consequences of this abnormal behavior if it exists on the behavior of certain thermodynamic properties of such mixtures.

Résumé: This work reports on the prediction of the liquid-vapor densities as well as the rectilinear diameter of argon in the vicinity of the critical region. A previously formulated equation of state (EOS) [A. Rizi, A. Abbaci, J. Mol. Liq. 171, 64 (2012)] based on the Landau-Ginzburg crossover formalism for argon is used for this purpose. We thus present a comparison of the crossover model equation of argon with the experimental phase equilibrium data and describe the singularity of the rectilinear diameter very close to the critical point. The obtained results show that percent deviations between the experimental data and the calculated rectilinear diameter from the crossover model do not exceed 0.05%.

Résumé: We present the viability of using thermally stable, practically non-volatile ionic liquids as corrosion inhibitors in aqueous monoethanolamine systems. Carbon steel 1020, which is widely used as a construction material in CO2 capture plants, has been taken as a test material. Corrosion inhibition capabilities of typical room-temperature ionic liquids constituting imidazolium cation in concentration range ≤3% in CO2 capture applications were investigated. Electrochemical corrosion experiments using the potentiodynamic polarization technique for measuring corrosion current were carried out. Subsequent calculation of corrosion rate via Tafel fit was performed. The experimental findings suggest that the corrosion rate is significantly dependent on the process parameters, such as the CO2 loading and the presence of oxygen. In addition, the value of the corrosion rate is sensitive to the type of ionic liquid added. Moreover, the results show that ionic liquids possess the ability of suppressing severe operational problems of corrosion in typical CO2 capture plants to a reasonable extent (≥50%).

Résumé: In our previous work [S. Azzouz, A. Rizi, A. Acidi, A. Abbaci, St. Cerc. St. CICBIA 11 (2) (2010) 235-241], we developed an interim thermodynamic property formulation for the supercritical n-hexane which incorporates non-analytic scaling laws in the critical region and reproduces the thermodynamic properties of n-hexane far away from the critical region. However, it appears that this equation of state gives unphysical values for critical amplitudes such as that of the compressibility above the critical point. In this work, we present a modification of this equation of state based on the pressure data of Grigoriev et al. group and those of Abdulagatov, the isochoric specific heat data of Amirkhanov et al. as well as the isobaric specific heat of Gerasimov et al. Comparison with different sets of thermodynamic-property data available is given.

Résumé: This paper presents a first report on chromium ISFET (ion-sensitive field effect transistor) based on a polymeric membrane (siloprene) including an ionophore (tributylphosphate) sensitive for hexavalent chromium. The sensor sensitivity as a function of the pH was studied; its value is minimum in a pH interval from 5.5 to 7.5. The sensitivity for hexavalent chromium was found to be 15 mV/loga Cr6+ in the range of 10-4 to 10-2 M. The detection limit was found to be 10-5 M. The studied interfering ions are Pb(II) and Cd(II) that do not represent a great perturbation upon the response for hexavalent chromium

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Résumé: The thermodynamic properties of fluids are predicted using global equations of state. Among these thermodynamic properties, we consider the densities of the liquid and vapor phases, pressure, the caloric properties such as specific heat at constant volume and specific heat at constant pressure and the speed of sound. In the present work, we apply the crossover theory to these thermodynamic properties and give a comparison of the crossover model equation of state with the experimental thermodynamic property data of ethane.

Résumé: The thermodynamic properties of fluids can be predicted using the global equations of state. Among these thermodynamic properties of fluids, we choose the densities of the liquid and vapor phases. This paper considers the application of the crossover model to the vapor-liquid rectilinear diameter of sulfurhexafluoride. We also present a comparison of the crossover model equation with the experimental data.

Résumé: The thermodynamic properties of fluids can be predicted using the global equations of state. Among these thermodynamic properties of fluids, we choose the densities of the liquid and vapor phases. This paper considers the application of the crossover model to the vapor-liquid rectilinear diameter of ethane. We also present a comparison of the crossover model equation with the experimental data.

Résumé: In this work we investigate the critical line of binary azeotropic mixtures of acetone-n-pentane. We pinpoint the abnormal behavior of the critical density line as a function of the mole fraction of one of the component and show its influence on other thermodynamic properties such as the volume, the enthalpy and the entropy.

Résumé: The applicability of the Liquid Surfactant Membrane (LSM) process for the removal and the concentration of lead and cobalt was investigated. The aim of this work is to find a process for the purification of wastewater, which contains cobalt and lead. A complete study of the metal extraction by the liquid membrane process using HDEHP as extractant and SPAN 80 as surfactant is performed in terms of extraction and stripping efficiencies, emulsion breaking and swelling. The results show that it is possible to recover 98.83% of cobalt and 94.21% of lead in the inner phase after 2 minutes of contacting time with a concentration factor of 50 for lead and 50 for cobat.

Résumé: This paper deals with an evaluation of the critical parameters reported for mixtures of carbon dioxide and ethane. Equations are presented for the critical parameters as a function of the concentration.

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Résumé: In a preceding publication [Z. Y. Chen, P. C. Albright, and J. V. Sengers, Phys. Rev. A 41, 3161 (1990)] a procedure for constructing a thermodynamic free energy of fluids was proposed that incorporates crossover from singular behavior at the critical point to regular behavior far away from the critical point. In the present paper this procedure, based on an approximate solution of the renormalization-group theory of critical phenomena, is further extended so that it can be used in conjunction with a six-term classical Landau expansion. The resulting thermodynamic free energy yields a satisfactory representation of the thermodynamic properties of fluids in a large range of temperatures and densities around the critical point, as is demonstrated by a comparison with experimental thermodynamic-property data for carbon dioxide, steam, and ethane.

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Résumé: Do to the fluctuations associated with the critical region of fluids. The behavior of thermodynamic properties these can not be predicted by mean field theories. To do so, a global equation of state based on the crossover model has been used. This equation of state is formulated on the basis of comparison of selected measurements of pressure-density-temperature data, isochoric and isobaric heat capacity of fluids.The model can be applied in a wide range of temperatures and densities around the critical point for ethane and methane. It is found that the developed model represents most of the reliable experimental data accurately.

Résumé: A new fundamental equation of state that describes the behavior of the thermodynamic properties of argon in the vicinity of the critical point is formulated. In this work, we present an equation of state based on the crossover model that takes into account not only the scaling laws at the critical point but also the classical behavior far away from the critical point. The new equation of state is constructed based on the new pressure data of Gilgen et al. from Bochum group. We give the comparison with different sets of thermodynamic-property data available, such as the pressure data, the specific heat data and the speed of sound data as well as a comparison with the accepted international equation for the thermodynamic properties of argon, developed by Stewart and Jacobsen. Graphical abstract

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