Sharif Digital Repository

In this work we have applied the Dense System Equation of State (DSEOS) to electrolyte solutions. We have found that this equation of state can predict the density of electrolyte solutions very accurately. It has been tested for different electrolytes solutions at different temperatures and compositions. A hypothetical binary model has been applied to find the dependencies of parameters of this equation of state on solution temperature and composition. Using such a simple model the heat capacity of NaCl solution was calculated for which the absolute percent deviation is less than 2 %. The DSEOS is tested for the following electrolytes: Na2SO4, MgCl2, MgSO4, KCl, NaCl, and NaBr. We found that... 

Based on our present knowledge on SARS-CoV-2 virus, which is collectively summarized in this work, it is shown that water plays a crucial role in stabilizing the virus, in such a way that its viability may reduce from a few days to a few seconds in the absence of water layer. Water not only provides a protective shell for the virus in which it is enveloped, but enhances its binding with the human cell. Therefore, one may conclude that the dehydration of the hydrated virus makes it much more vulnerable, due to the fact that if it is exposed to many chemicals it will be deactivated; even by particles in air, such as ozone, singlet oxygen and pollutants. Thermodynamically, the dehydration may... 

Based on our present knowledge on SARS-CoV-2 virus, which is collectively summarized in this work, it is shown that water plays a crucial role in stabilizing the virus, in such a way that its viability may reduce from a few days to a few seconds in the absence of water layer. Water not only provides a protective shell for the virus in which it is enveloped, but enhances its binding with the human cell. Therefore, one may conclude that the dehydration of the hydrated virus makes it much more vulnerable, due to the fact that if it is exposed to many chemicals it will be deactivated; even by particles in air, such as ozone, singlet oxygen and pollutants. Thermodynamically, the dehydration may... 

In this work, we consider each normal alkane as a hypothetical mixture of methyl and methylene groups, in which the interaction potential of each pair is assumed to be the average effective pair potential. Then, the LIR equation of state (EOS) is extended for such a hypothetical mixture. Also, three basic compounds, namely, propane, n-butane and cyclohexane, are used to obtain the contribution of each carbonic group in the EOS parameters. Using the calculated EOS parameters along with the modified EOS, the density of n-alkanes and their mixtures at different pressures and temperatures are calculated. The average percentage error in density is found to be less than 1.5% for both the pure... 

In this work, a new method based on the modified Enskog theory (MET) is presented for calculation of transport properties at high densities (ρ > ρc). The main limitation of using the MET is lack of experimental data for co-volume, b0. We have substituted b0 from hard sphere (HS) theory and zero density transport properties from the kinetic theory of gases for HS in the MET expression, because of the fact that dense fluids behave more and less like a HS fluid. As a result, a simple linear expression for the self diffusion (D) and quadratic expressions for viscosity (η) and thermal conductivity (λ) coefficients have been obtained in terms of Y at high densities (ρ > ρc), where Y = (T (∂ p / ∂... 

Recently, a new potential model has been proposed for the intermolecular interactions of model pure fluids and it was shown that the derived Equation Of State (EOS), based on this potential, can properly predict the thermodynamic properties of these.fluids. In addition to simplicity and, to some extent, the realistic form, this potential has a parameter (α) which controls the range of the attraction tail. In the first part of this study, the proposed potential and derived EOS are extended to binary mixtures of model fluids. In a similar manner to that of the pure fluids, the results obtained are consistent with the data available from simulation studies. In the second part, after... 

Different equations of state (EOSs) have been used to obtain analytical expressions for the ideal curves, namely, the Joule-Thomson inversion curve (JTIC), Boyle curve (BC), and Joule inversion curve (JIC). The selected EOSs are the Redlich-Kwong (RK), Soave-Redlich-Kwong (SRK), Deiters, linear isotherm regularity (LIR), modified LIR (MLIR), dense system equation of state (DSEOS), and van der Waals (vdW). Analytical expressions have been obtained for the JTIC and BC only by using the LIR, MLIR, and vdW equations of state. The expression obtained using the LIR is the simplest. The experimental data for the JTIC and the calculated points from the empirical EOSs for the BC are well fitted into... 

A new hard-core potential model was recently used to calculate thermodynamic properties of some model fluids, including equilibrium properties, such as compressibility factor and internal energy. A Lennard-Jones (LJ) like potential has been used to modify the repulsive part of the potential. The modified potential contains five parameters, namely, R, and HS. The parameter is the tail of the attractive branch whose value changes from zero to one. In this work, we have chosen = 1 to make the potential continuous at separation r = R, where the parameter R is the well width. R lies in the range 1.2 to 2.5, and R = 1.3 was found to be the best value for all real gases studied. The parameter is...