Genetic programming (GP) is one of the computer algorithms in the family of evolutionary-computational methods, which have been shown to provide reliable solutions to complex optimization problems. The genetic programming under discussion in this work relies on tree-like building blocks, and thus supports process modeling with varying structure. In this paper the systems containing amino ac...

For an adequate choice or design of ionic liquids, the knowledge of their interaction with other solutes and solvents is an essential feature for predicting the reactivity and selectivity of systems involving these compounds. In this work, the activity coefficient of water in several imidazolium-based ionic liquids with the common cation 1-butyl-3-methylimidazolium was measured at 298.2 K. To c...

A procedure is described for the calculation of activity and osmotic coefficients which is based upon a knowledge of the equilibria in solutl.on and assumed si.ngle-ion activity coefficients. The procedure permits one to introduce chemical equilibria of various types (ion-pairing, complexation, hydration, and hydrolysis) into a model which can be used to calculate values of the excess Gibbs ene...

We construct a mean-field variational model to study how the dependence of dielectric coefficient (i.e., relative permittivity) on local ionic concentrations affects the electrostatic interaction in an ionic solution near a charged surface. The electrostatic free-energy functional of ionic concentrations, which is the key object in our model, consists mainly of the electrostatic potential energ...

Free acidity of aqueous solutions was initially defined in 1909 by Søren Peter Lauritz Sørensen as pH = −lgcH+ (c/mol·dm−3 or m/mol·kg−1 of the free hydrogen ions in solution, H+) soon (1910) was changed to pH = paH+ = −lgaH+, integrating the new concepts of activity, ai and activity coefficient γi, for the ionic species i under concern, H+ in this case; it is ai = −lg(miγi). Since individual i...

in this work the effect of electrolytes on hydrate formation was investigated. to do so, a new model was used in predicting the hydrate formation conditions in presence of both single and mixed electrolyte solutions. the new model is based on the van der waals - platteeuw hydrate equation of state. in order to evaluate the values for the activity of water in electrolyte solutions the simplified...

the solubility of kno3 in the mixed solvent (water 85%+methanol 15%) were determined by using solvent evaporating method at different temperatures (25, 30, 40, 50, 60 ;c). in addition the equilibrium constant of ion pair formation, kip, for k+no3 – ion-pair on the basis of fuoss contact ion pair model was calculated. upon choosing the extended debye-hückel model for estimating the mean activity...

We propose a simple model to explain the nonmonotonic concentration dependence of the mean activity coefficient of simple electrolytes without using any adjustable parameters. The primitive model of electrolytes is used to describe the interaction between ions computed by the adaptive grand canonical Monte Carlo method. For the dielectric constant of the electrolyte, we use experimental concent...

in this work, the results concerning to the mean activity coefficient measurements for nacl in the (glycerol + water) system using the potentiometric method are reported. the potentiometric measurements were performed on the galvanic cells without liquid junction of the type: ag|agcl|nacl (m), glycerol (wt%), h2o (1 - wt)%|na-ise, in various mixed solvent systems containing 0, 5, 10, 20 and 30 ...