scholarly journals Isopiestic Investigation of the Osmotic and Activity Coefficients of Aqueous NaBr and the Solubility of NaBr·2H2O(cr) at 298.15 K:  Thermodynamic Properties of the NaBr + H2O System over Wide Ranges of Temperature and Pressure

1997 ◽  
Vol 42 (2) ◽  
pp. 414-414
Author(s):  
Joseph A. Rard ◽  
Donald G. Archer
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
GuoWei Zhang ◽  
Chao Xu ◽  
MingJie Wang ◽  
Ying Dong ◽  
FengEr Sun ◽  
...  

AbstractFirst principle calculations were performed to investigate the structural, mechanical, electronic properties, and thermodynamic properties of three binary Mg–B compounds under pressure, by using the first principle method. The results implied that the structural parameters and the mechanical properties of the Mg–B compounds without pressure are well matched with the obtainable theoretically simulated values and experimental data. The obtained pressure–volume and energy–volume revealed that the three Mg–B compounds were mechanically stable, and the volume variation decreases with an increase in the boron content. The shear and volume deformation resistance indicated that the elastic constant Cij and bulk modulus B increased when the pressure increased up to 40 GPa, and that MgB7 had the strongest capacity to resist shear and volume deformation at zero pressure, which indicated the highest hardness. Meanwhile, MgB4 exhibited a ductility transformation behaviour at 30 GPa, and MgB2 and MgB7 displayed a brittle nature under all the considered pressure conditions. The anisotropy of the three Mg–B compounds under pressure were arranged as follows: MgB4 > MgB2 > MgB7. Moreover, the total density of states varied slightly and decreased with an increase in the pressure. The Debye temperature ΘD of the Mg–B compounds gradually increased with an increase in the pressure and the boron content. The temperature and pressure dependence of the heat capacity and the thermal expansion coefficient α were both obtained on the basis of Debye model under increased pressure from 0 to 40 GPa and increased temperatures. This paper brings a convenient understanding of the magnesium–boron alloys.


2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Omid Askari

Chemical composition and thermodynamics properties of different thermal plasmas are calculated in a wide range of temperatures (300–100,000 K) and pressures (10−6–100 atm). The calculation is performed in dissociation and ionization temperature ranges using statistical thermodynamic modeling. The thermodynamic properties considered in this study are enthalpy, entropy, Gibbs free energy, specific heat at constant pressure, specific heat ratio, speed of sound, mean molar mass, and degree of ionization. The calculations have been done for seven pure plasmas such as hydrogen, helium, carbon, nitrogen, oxygen, neon, and argon. In this study, the Debye–Huckel cutoff criterion in conjunction with the Griem’s self-consistent model is applied for terminating the electronic partition function series and to calculate the reduction of the ionization potential. The Rydberg and Ritz extrapolation laws have been used for energy levels which are not observed in tabulated data. Two different methods called complete chemical equilibrium and progressive methods are presented to find the composition of available species. The calculated pure plasma properties are then presented as functions of temperature and pressure, in terms of a new set of thermodynamically self-consistent correlations for efficient use in computational fluid dynamic (CFD) simulations. The results have been shown excellent agreement with literature. The results from pure plasmas as a reliable reference source in conjunction with an alternative method are then used to calculate the thermodynamic properties of any arbitrary plasma mixtures (mixed plasmas) having elemental atoms of H, He, C, N, O, Ne, and Ar in their chemical structure.


1981 ◽  
Vol 34 (3) ◽  
pp. 479 ◽  
Author(s):  
H Bloom ◽  
MS White

The electromotive forces of galvanic cells for the formation of PbBr2 in the molten binary salt systems, PbBr2-KBr, PbBr2,-RbBr and PbBr2-CsBr, have been measured. Activities, activity coefficients and partial molar free energies have been calculated for each component of the three systems. Integral free energies of mixing have also been calculated. Various models of mixing of molten salts have been applied to the results. The systems contain complex ions, probably mixtures of PbBr42-, PbBr64- with some PbBr3-.


2011 ◽  
Vol 391-392 ◽  
pp. 1017-1021
Author(s):  
Ru Zhang ◽  
Yan Fen Wu ◽  
Ping Hu

Six binary silane systems were chosen to calculate the activity coefficients (γ) and free energies of mixing (ΔGm). These systems included: methyldichlorosilane + methyltrichlorosilane, methyldichlorosilane + methylvinyldichlorosilane, methyldichlorosilane + toluene, methyltrichlorosilane + methylvinyldichlorosilane, methyltrichlorosilane + toluene, methylvinyldichlorosilane + toluene. Based on the Antoine constants, critical parameters of the pure components and Wilson model parameters, γ and ΔGmwere calculated. The influence factors of these thermodynamic properties were also discussed.


2015 ◽  
Vol 1092-1093 ◽  
pp. 1455-1459
Author(s):  
Chu Yue Hou ◽  
Gui Ying Zhou ◽  
Jian Kang Wen ◽  
Biao Wu

In this paper, we jointly use the Pitzer model and the Meissner model to study thermodynamic laws of bioleaching solution in a lean nickel-cobalt ore in the Jilin Baishan, by using the Pitzer model to calculate activity coefficients of single electrolyte aqueous solutions and the Meissner model to calculate activity coefficients of components in the bioleaching solution. Also we studied the rules of activity coefficient of NiSO4 and CoSO4 in the solution. Results show that when separating and purifying foreign ions from bioleaching solution of the lean nickel-cobalt ore, the descending sequence of their ion concentration’s effect over the solution is Mg2+, Fe3+, Fe2+, Ni2+, Co2+ and Ca2+.


2018 ◽  
Vol 57 (14) ◽  
pp. 5128-5135 ◽  
Author(s):  
Zachariah S. Baird ◽  
Petri Uusi-Kyyny ◽  
Oliver Järvik ◽  
Vahur Oja ◽  
Ville Alopaeus

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