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Showing papers on "Mass action law published in 2009"


Journal ArticleDOI
TL;DR: In this article, equilibrium and kinetic data of the ion exchange of sodium from glycerol-water mixtures on the strong acid resin Amberlite-252 were obtained, and basic parameters for the design of ion exchange units for the purification of the crude glycerols phase from biodiesel production have been determined.
Abstract: BACKGROUND: In this study, equilibrium and kinetic data of the ion exchange of sodium from glycerol–water mixtures on the strong acid resin Amberlite-252 were obtained. Basic parameters for the design of ion exchange units for the purification of the crude glycerol phase from biodiesel production have been determined. RESULTS: Equilibrium uptake of sodium ions with the strong acid ion exchanger Amberlite-252 was studied at three temperatures. The Langmuir equation and the mass action law model were used to fit the experimental equilibrium data. Equilibrium constants and thermodynamic parameters were obtained at each temperature. Kinetic experiments were carried out to evaluate the effective diffusion coefficients of sodium on the resin Amberlite-252 in glycerine–water media. CONCLUSIONS: Equilibrium results indicate that this process is favourable and also that its selectivity decreases with temperature increase from 303 to 333 K. Both models were able to fit the experimental equilibrium data. Kinetic experiments showed that the rate of mass transfer in this binary system is high. An Arrhenius type equation allowed the correlation of effective diffusion coefficients and temperature. The results indicate that the macroporous resin Amberlite-252 could be useful for removal of sodium ions from glycerine/water solutions with a high salt concentration. Copyright © 2008 Society of Chemical Industry

55 citations


Journal Article
TL;DR: In this paper, a mean spherical approximation based mass action law approach was developed to describe the influence of ion association on solvent and solution dielectric constants in electrolyte solutions. But the results were compared with recent experimental data for aqueous solutions of nitrate and formate salts and a fair agreement was obtained.
Abstract: Mean spherical approximation - mass action law approach is developed to describe the influence of ion association on solvent and solution dielectric constants in electrolyte solutions. The dependences of the dielectric constants on electrolyte concentration, ionic sizes, and the degree of ion association are analyzed. The results are compared with recent experimental data for aqueous solutions of nitrate and formate salts and a fair agreement is obtained.

12 citations


Journal ArticleDOI
TL;DR: In this paper, a new chemical model is presented that permits the calculation of excess functions and phase equilibria for binary and ternary systems with one associating component, which is similar to those in the previously published model CONTAS, but continuous thermodynamics is not used.

11 citations


Journal ArticleDOI
TL;DR: In this paper, the mass-action kinetic law is shown to be restricted to a mixture of fluids with linear transport properties, and a simplified form of polynomial approximation to a general rate function derived by non-equilibrium thermodynamics is proposed.
Abstract: Using several reaction examples with experimentally determined rate equations, traditional mass-action rate equations are shown to be simplified forms of polynomial approximation to a general rate function derived by non-equilibrium thermodynamics for a mixture of fluids with linear transport properties. The mass-action kinetic law is thus proved also on the macroscopic level and limited to this type of fluids.

6 citations


Proceedings ArticleDOI
25 May 2009
TL;DR: The carrier velocity for 2-dimensional (2-D) p-type nanostructure was simulated and it is revealed that the velocity is strongly dependent on concentration and becomes independent of temperature at high concentration.
Abstract: The carrier velocity for 2-dimensional (2-D) p-type nanostructure was simulated in this paper. According to the energy band diagram, the effective mass (m*) in the p-type silicon is mostly dominated by heavy hole because of the large gap between heavy hole and light hole in k = 0. The carrier concentration calculation for 2-D, based on the Fermi – Dirac statistic on the order of zero ( ), was applied to obtain the intrinsic velocity of carrier, in the term of thermal velocity vth. The results for 2-D carrier velocity were modeled and simulated, and the comparison for degenerate and non-degenerate regime is presented for various temperature and concentration. It is revealed that the velocity is strongly dependent on concentration and becomes independent of temperature at high concentration.

3 citations


Journal ArticleDOI
TL;DR: In this article, a theory for carrier concentration in physically doped organic semiconductors has been presented based on Gaussian energy distribution of the lowest unoccupied molecular orbitals (LUMOs) and the highest occupied molecular orbitALS >, as well as the Fermi - Dirac distribution of carriers in allowed quantum states.
Abstract: A theory for carrier concentration in physically doped organic semiconductors has been presented based on Gaussian energy distribution of the lowest unoccupied molecular orbitals (LUMOs) and the highest occupied molecular orbitals (HOMOs) as well as the Fermi - Dirac distribution of carriers in allowed quantum states. The dependence of carrier concentration on doping concentration, ambient temperature and energy gap of organic semiconductors were numerically investigated. It is shown that carrier concentration will increase with the ambient temperature in doped or undoped organic semiconductors, and the carrier concentration decreases exponentially with the reciprocal of temperature. For intrinsic organic semiconductor, carrier concentration will decrease exponentially with the energy gap (the difference between the average energy levels of HOMO and LUMO )and increase exponentially with the square of the width of Gaussian distribution. We then discussed the effect of doping concentration on carrier concentration for different HOMO and LUMO positions of the dopant relative to that of the host.

2 citations


Journal ArticleDOI
TL;DR: In this paper, a theoretical treatment of ionic micelle formation based on the Mass Action Law (i.e. on the molecular concept) is presented, and the expression for the thermodynamic equilibrium constant micelles were considered as molecular entities.