Models for the prediction of conductance in nonbrine water samples through the measurement of ionic concentrations and other parameters are compared. Such predictions are often used for quality assurance purposes by comparing them with actual measurements to determine whether gross analysis errors have been made. A currently recommended method for making such predictions is a semiempirical rela...

In this work, an electrolyte-UNIQUAC model was developed by replacement of Boltzmann weight binary interaction parameters by the nonextensive Tsallis weight. A summation of the long-range electrostatic term (Debye-Huckel equation) and a short-range interaction term were considered in the calculation of thermodynamic properties. A framework proposed by Chen and co-workers was employed for the de...

The present study deals with the contribution of the surface atomic layer to the specific heat of nanocrystals. In the case of small phases with comparable number of bulk and surface atoms, the variation of heat capacity with respect to that of infinitely large phase is significant. To evaluate this variation, in the framework of the classical Debye model, we introduce surface excess heat capac...

The boson peak is an excess in the phonon density of states compared to the Debye model that appears in almost all glasses. It has been repeatedly measured in the bulk by a variety of methods, but its origin is still highly debated. Here we present first experimental evidence of the boson peak on the v-SiO2 surface. The measurements were obtained by helium atom scattering. The boson peak appear...

using solvent evaporating and atomic emission spectrophotometric methods, the solubility of li2co3 in waterat 25°c was determined. comparing the value of thermodynamic solubility product constant, ksp(th),(ksp(tn) = exp(—ag.ss/rt)) of the mentioned salt to the value which is obtained from the observed solubility,shnoll-1 , and activity coefficients, f+ and f, which are estimated upon the extend...

This paper presents an approach to storing semistructured data in relational databases. We focus on semistructured data as extracted from Web pages by a tool called DEByE (Data Extraction By Example), and organized according to its data model, the DEByE Object Model (DEByE-OM). The approach presented here consists in representing the structure of objects extracted by DEByE by a relational schem...