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...

A nanocomposite membrane Cu2+ ion-selective electrode has been constructed using a new compound ethyl 1,2,3,4-tetrahydro-4-(4-methoxyphenyl)-6-methyl-2-oxopyrimidine-5-carboxylat (ETMOC) as a neutral ionophore. The electrode works properly. It responds to Cu2+ ion with a sensitivity of 29.5 ± 0.2 mV/decade over the range 1.0 × 10−9 to 5.0 × 10−1M at p...

A synthetic Topopah Spring Tuff water representative of one type of pore water at Yucca Mountain, NV was evaporated at 95 °C in a series of experiments to determine the geochemical controls for brines that may form on, and possibly impact upon the long-term integrity of waste containers and drip shields at the designated high-level, nuclear-waste repository. Solution chemistry, condensed vapor ...

A procedure that automatically identifies internal rotation modes and rotating groups during the normal mode vibrational analysis is outlined, and an improved approximation to the corrections for the thermodynamic functions is proposed. The identification and the characterization of the internal rotation modes require no user intervention and make extensive use of the information imbedded in th...

A nanocomposite membrane Cu2+ ion-selective electrode has been constructed using a new compound ethyl 1,2,3,4-tetrahydro-4-(4-methoxyphenyl)-6-methyl-2-oxopyrimidine-5-carboxylat (ETMOC) as a neutral ionophore. The electrode works properly. It responds to Cu2+ ion with a sensitivity of 29.5 ± 0.2 mV/decade over the range 1.0 × 10−9 to 5.0 × 10−1M at p...

Introduction: The Mars Exploration Rover (MER) missions have stimulated considerable thinking about the surficial geochemical evolution of Mars [1-4]. Among the major MER findings is the presence of the mineral, jarosite (a ferric sulfate salt), which suggests formation from an acid-sulfate brine. The objectives of this work were to (1) add ferric iron chemistry to an existing ferrous iron mode...

An extension of the corresponding states approach of Pitzer and of Lee and Kesler (PitzerLee-Kesler (PLK) strategy) based on the work of Teja et al. (PLKT strategy) provides a clear pedagogical setting for describing the underlying basis of the PLK strategy itself and also its extension to families of non-normal fluids. Application of the strategy to two families of nonnormal fluids is illustra...

This research has demonstrated that simple structural and potential models can qualitatively and quantitatively predict properties in dense hydrothermal solutions of sodium chloride and water using molecular dynamics simulation. The PTFxi behavior of simulated model systems at 250 bar and 21 wt % NaCl compared favorably to experimental data from ambient to near-critical temperatures as represen...

We present the first systematic investigation of Tc(iv) solubility, hydrolysis and speciation in dilute to concentrated NaCl, MgCl2 and CaCl2 systems, and comprehensive thermodynamic and activity models for the system Tc(4+)-H(+)-Na(+)-Mg(2+)-Ca(2+)-OH(-)-Cl(-)-H2O using both SIT and Pitzer approaches. The results are advancing the fundamental scientific understanding of Tc(iv) solution chemist...