The conductance behaviour of NaI and NaBPh4 in acetone and in isopropanol at 10, 15, 20, 25, and 30 °C

1989 ◽  
Vol 54 (6) ◽  
pp. 1475-1481 ◽  
Author(s):  
N. Papadopoulos ◽  
G. Ritzoulis

Molar conductivities at the limit of zero concentration have been evaluated for NaI and NaBPh4 in acetone and in isopropanol at 10, 15, 20, 25, and 30 °C. The experimental data have been analysed by means of the Lee-Wheaton equation. The thermodynamic parameters of the non-coulombic interaction have been evaluated.

1989 ◽  
Vol 67 (10) ◽  
pp. 1624-1627 ◽  
Author(s):  
N. Papadopoulos

The limiting molar conductances and association constants for NaBPh4 have been evaluated in acentonitrile–toluene mixtures at 15, 25, and 35 °C. Experimental data have been analysed by the Lee–Wheaton conductance equation. The thermodynamic parameters of the non-coulombic interaction have been evaluated. Keywords: conductance, association constant, Lee–Wheaton equation, acetonitrile–toulene.


Author(s):  
Ivan Saenko ◽  
O. Fabrichnaya

AbstractThermodynamic parameters were assessed for the MgO–FeOx system and combined with already available descriptions of ZrO2-FeOx and ZrO2-MgO systems to calculate preliminary phase diagrams for planning experimental investigations. Samples of selected compositions were heat treated at 1523, 1673 and 1873 K and characterized using x-ray and scanning electron microscopy combined with energy dispersive x-ray spectroscopy (SEM/EDX). Experiments indicated extension of cubic ZrO2 solid solution into the ternary system at 1873 K (75 mol.% ZrO2, 10 mol.% FeOx and 15 mol.% MgO) and limited solubility of 4 mol.% ZrO2 in spinel phase. Based on the obtained results thermodynamic parameters of C-ZrO2 and spinel phase were optimized.


2015 ◽  
Vol 51 (2) ◽  
pp. 125-132 ◽  
Author(s):  
B. Hu ◽  
Y. Du ◽  
J.J. Yuan ◽  
Z.F. Liu ◽  
Q.P. Wang

Iased on the new experimental data available in the literature, the Mn-Ni-Si system has been reassessed using the CALPHAD (CALculation of PHAse Diagram) approach. Compared with the previous modeling, the ?8 and ?12 ternary phases were treated as the same phase according to the new experimental data. The Mn3Si phase was described with two sublattice model (Mn, Ni)3(Si)1. The reported new ternary phase ? was not considered in the present work. Comprehensive comparisons between the calculated and measured phase diagrams showed that a set of thermodynamic parameters of the Mn-Ni-Si system obtained in this work was more accurate than the previous one.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Sondes Bouabdallah ◽  
Med Thaieb Ben Dhia ◽  
Med Rida Driss

The isomerization of lisinopril has been investigated using chromatographic, NMR spectroscopic, and theoretical calculations. The NMR data, particularly the NOEDIFF experiments, show that the major species that was eluted first is thetransform. The proportion was 77% and 23% for thetransandcis, respectively. The thermodynamic parameters (ΔH,ΔS, andΔG) were determined by varying the temperature in the NMR experiments. The interpretations of the experimental data were further supported by DFT/B3LYP calculations.


Clay Minerals ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 85-95 ◽  
Author(s):  
İ. Sargin ◽  
N. Ünlü

AbstractIn this study, adsorption and adsorption kinetics of methyl violet dye from aqueous solutions onto kaolinite were investigated. The effects of adsorbent dosage, pH, ionic strength, contact time, temperature and initial dye concentration were studied. Kinetic and thermodynamic parameters were determined using experimental data. Adsorption capacity decreased with increasing ionic strength. Changes in the initial pH of the dye solution in a range close to the dye's natural pH (i.e. ∼ pH 5.0) values affected adsorption capacity slightly, indicating that adsorption studies could be carried out at the dye's natural pH. The adsorption process followed the Freundlich-type adsorption isotherms and pseudo-second order type adsorption kinetics. However, an intraparticle diffusion process was found to have effects in adsorption processes. Thermodynamic parameters were calculated from the experimental data and enthalpy of the adsorption, ΔH0, was found to be –6.82 kJ mol–1, indicating physisorption nature of the adsorption. Other thermodynamic parameters, ΔS0 and DG0, were also calculated. Negative values of ΔG0 indicated that the adsorption process for methyl violet on kaolinite is spontaneous.


2019 ◽  
Vol 89 (8) ◽  
pp. 1158
Author(s):  
К.К. Маевский ◽  
С.А. Кинеловский

The modified equation of state is proposed for the calculation of thermodynamically equilibrium model TEС2 to improve the reliability of the description of thermodynamic parameters of shock-wave loading of pure materials and heterogeneous mixtures of different porosity. The parameters of the thermally consistent equation of state are determined for copper. A reliable description of the shock-wave loading of copper is obtained for a small number of fitting parameters determined by the experimental data. The thermodynamic parameters for copper of different porosity are modeled, the compression and temperature values along the shock adiabate are determined; the heat capacity value along the normal isobar is calculated. The results of calculations are compared with the known experimental results of different authors.


2021 ◽  
Vol 2052 (1) ◽  
pp. 012015
Author(s):  
N V Gerasimov ◽  
M A Zakharov

Abstract In this work we describe how to efficiently calculate thermodynamic properties and T-x diagram of binary As-Te solution in the generalized lattice model. All the thermodynamic parameters of the As-Te solution are obtained within framework of the generalized lattice model. The binary phase diagram of As-Te system is calculated and good agreement with experimental data is obtained.


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3692
Author(s):  
Oana Buriac ◽  
Mihaela Ciopec ◽  
Narcis Duţeanu ◽  
Adina Negrea ◽  
Petru Negrea ◽  
...  

Platinum is a precious metal with many applications, such as: catalytic converters, laboratory equipment, electrical contacts and electrodes, digital thermometers, dentistry, and jewellery. Due to its broad usage, it is essential to recover it from waste solutions resulted out of different technological processes in which it is used. Over the years, several recovery techniques were developed, adsorption being one of the simplest, effective and economical method used for platinum recovery. In the present paper a new adsorbent material (XAD7-DB30C10) for Pt (IV) recovery was used. Produced adsorbent material was characterized by X-ray dispersion (EDX), scanning electron microscopy (SEM) analysis, Fourier Transform Infrared Spectroscopy and Brunauer-Emmett-Teller (BET) surface area analysis. Adsorption isotherms, kinetic models, thermodynamic parameters and adsorption mechanism are presented in this paper. Experimental data were fitted using three non-linear adsorption isotherms: Langmuir, Freundlich and Sips, being better fitted by Sips adsorption isotherm. Obtained kinetic data were correlated well with the pseudo-second-order kinetic model, indicating that the chemical sorption was the rate-limiting step. Thermodynamic parameters (ΔG°, ΔH°, ΔS°) showed that the adsorption process was endothermic and spontaneous. After adsorption, metallic platinum was recovered from the exhausted adsorbent material by thermal treatment. Adsorption process optimisation by design of experiments was also performed, using as input obtained experimental data, and taking into account that initial platinum concentration and contact time have a significant effect on the adsorption capacity. From the optimisation process, it has been found that the maximum adsorption capacity is obtained at the maximum variation domains of the factors. By optimizing the process, a maximum adsorption capacity of 15.03 mg g−1 was achieved at a contact time of 190 min, initial concentration of 141.06 mg L−1 and the temperature of 45 °C.


2017 ◽  
Vol 68 (3) ◽  
pp. 527-529
Author(s):  
Irina Pincovschi ◽  
Nicoleta Neacsu ◽  
Cristina Modrogan ◽  
Mircea Stefan

The adsorption of cadmium and zinc ions from waste waters in agricultural argilaceaus soils have been studied, using a thermodynamic method in order to put in evidence the influence of adsorption conditions on adsorption degree. The adsorption isotherms, Langmuir and Freundlich, have been used to describe the adsorption equilibrium. The experimental data put in evidence that Cd2+ ions are more adsorbable (about 300 mmol/g) than Zn2+ ones (about 200 mmol/g). The Langmuir isotherms reflect more exactly the adsorption process of both Cd2+and Zn2+ ions, being recommended for thermodynamic parameters determination.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6879
Author(s):  
Andrii Rusanov ◽  
Roman Rusanov ◽  
Piotr Klonowicz ◽  
Piotr Lampart ◽  
Grzegorz Żywica ◽  
...  

The article describes an interpolation–analytical method of reconstruction of the IAPWS-95 equations of state and the modified Benedict–Webb–Rubin equations of state with 32 terms (mBWR32). The method enables us to provide the thermodynamic closure in 3D computational fluid dynamics (CFD) calculations of turbomachinery flows with real working media, such as steam and Organic Rankine Cycle (ORC) fluids. The described approach allows for the sufficient accuracy of 3D flow calculations and does not require a significant increase in computational cost over perfect gas calculations. The method is validated against experimental data from measurements and compared with computational results from the model using the Tammann equation of state. Three turbine blading systems are considered—a multi-stage configuration from a low-pressure cylinder of a large-power steam turbine and two ORC microturbines working with organic media HFE7100 and R227ea. The calculation results obtained using the described method of approximation of the IAPWS-95 and mBWR32 equations exhibit satisfactory agreement with the experimental data, considering pressures, temperatures and enthalpies in key sections, as well as turbine power and efficiency in a wide range of changing thermodynamic parameters. In contrast, the Tammann equation of state provides acceptable results only for relatively small changes of thermodynamic parameters.


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