The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Hertanto Adidharma - One of the best experts on this subject based on the ideXlab platform.
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prediction of Molar Volume and partial Molar Volume for co2 ionic liquid systems with heterosegmented statistical associating fluid theory
Fluid Phase Equilibria, 2012Co-Authors: Xiaoyan Ji, Hertanto AdidharmaAbstract:Abstract To design ionic liquids (ILs) as effective liquid absorbents for CO2 separation from flue or synthesis gases, it is necessary to know the properties and phase equilibria of the CO2/IL systems. The Molar Volumes of CO2/IL mixtures are predicted with the heterosegmented statistical associating fluid theory equation of state. The comparison with the available experimental data shows that the model can be used to predict reliably the Molar Volumes of CO2/IL mixtures from 293 to 413 K and pressures up to 160 bar. In addition, the partial Molar Volume of CO2 in CO2/IL mixtures and the partial Molar Volume of CO2 at infinite dilution in an IL are also predicted.
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Prediction of Molar Volume and partial Molar Volume for CO2/ionic liquid systems with heterosegmented statistical associating fluid theory
Fluid Phase Equilibria, 2012Co-Authors: Xiaoyan Ji, Hertanto AdidharmaAbstract:Abstract To design ionic liquids (ILs) as effective liquid absorbents for CO2 separation from flue or synthesis gases, it is necessary to know the properties and phase equilibria of the CO2/IL systems. The Molar Volumes of CO2/IL mixtures are predicted with the heterosegmented statistical associating fluid theory equation of state. The comparison with the available experimental data shows that the model can be used to predict reliably the Molar Volumes of CO2/IL mixtures from 293 to 413 K and pressures up to 160 bar. In addition, the partial Molar Volume of CO2 in CO2/IL mixtures and the partial Molar Volume of CO2 at infinite dilution in an IL are also predicted.
Wei Liu - One of the best experts on this subject based on the ideXlab platform.
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integrated modeling of Molar Volume of the sigma phase aided by first principles calculations
Journal of Alloys and Compounds, 2019Co-Authors: Wei Liu, Hao Wang, Yi LiuAbstract:Abstract The Volume modeling of the sigma phase is an indispensable complement to the integrated computational material design of technologically important materials, such as high-alloy steels and Ni-based superalloys. The Molar Volume of the sigma phase is influenced by both the atomic mixing (the Volume variation affected by this factor is caused by composition alteration rather than site occupation change) and atomic order (i.e. atomic constituent distribution or site occupancy preference on inequivalent sites of a crystal). In the present work, we developed a new integrated thermodynamic and Molar Volume model to consider physically both mixing and order factors. The integrated model was built within the compound energy formalism (CEF), enabling the thermodynamic calculations to determine equilibrium site occupancies for the subsequent Volume calculations. The model parameters of the CEF were assigned by using the first-principles calculated energies and Molar Volumes of the complete sets of ordered configurations of the sigma phase, as well as the extrapolated Molar Volumes of the pure elements in the hypothetic sigma phase structure. Such extrapolation for pure elements is based on the experimental data from the literature and the first-principles calculations. We applied the integrated model to study the binary compounds, e.g. Cr-Co, Cr-Fe, Cr-Mn, Mo-Fe, Mo-Mn, Mo-Re, Re-Cr, Re-Fe, Re-Mn, Nb-Al, Ta-Al, V-Fe, V-Ni, and ternary compounds Cr-Fe-X (X = Co and Ni). The integrated thermodynamic and Molar Volume databases can predict successfully the Molar Volume of the binary and ternary sigma compounds. As most experimental Volume data were measured at room temperature and atmospheric pressure, and the first-principles calculations were performed at 0 K, the present model parameters are valid at about room temperature and atmospheric pressure.
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Assessments of Molar Volume of the binary C14 Laves phase
Calphad, 2015Co-Authors: Jing-yong Zhao, Wei LiuAbstract:Abstract The Molar Volume of the C14 Laves phase has been evaluated at room temperature and atmospheric pressure for binary systems involving 31 elemental metals (i.e. Al, Ba, Be, Co, Cr, Fe, Hf, Lu, Mg, Mn, Mo, Na, Nb, Nd, Os, Pr, Re, Ru, Sc, Sm, Sr, Ta, Tb, Ti, Tm, V, W, Y, Yb, Zn and Zr) based on experimental data from the literature by means of the CALPHAD approach. The Molar Volume model adopted in the present work expresses the Molar Volume of a non-stoichiometric C14 Laves phase as a linear average of Volumes of the constituting elements in the hypothetic C14 Laves structure. Model parameters have been obtained and yield reasonable descriptions of most experimental data. As a further comparison, the Molar Volume of the C14 Laves phase obtained by the first-principles calculations was compared with the assessment results which illustrates a reasonable consistency.
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Modeling of Molar Volume of the sigma phase involving transition elements
Computational Materials Science, 2014Co-Authors: Wei LiuAbstract:The Molar Volume of the sigma phase has been modeled and evaluated at room temperature and atmospheric pressure for binary systems concerning 19 transition elements Au, Co, Cr, Fe, Ir, Mo, Nb, Ni, Os, Pd, Pt, Re, Rh, Ru, Ta, Tc, V, W and Zr by using the CALPHAD approach. The Volume model proposed in this work expresses the Molar Volume of a non-stoichiometric sigma phase as a linear average of Volumes of the constituting elements in their hypothetic sigma structure, which can be assessed as model parameters based on experimental data from the literature. Reasonable model parameters have been obtained giving a best description of most experimental data. For comparison, Volumes of the 19 transition elements in the sigma structure have been calculated by first-principles calculations. The results are compatible with the assessed values.
Giuseppe Graziano - One of the best experts on this subject based on the ideXlab platform.
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partial Molar Volume of n alcohols at infinite dilution in water calculated by means of scaled particle theory
Journal of Chemical Physics, 2006Co-Authors: Giuseppe GrazianoAbstract:The partial Molar Volume of n-alcohols at infinite dilution in water is smaller than the Molar voulme in the neat liquid phase. It is shown that the formula for the partial Molar Volume at infinite dilution obtained from the scaled particle theory equation of state for binary hard sphere mixtures is able to reproduce in a satisfactory manner the experimental data over a large temperature range. This finding implies that the packing effects play the fundamental role in determining the partial Molar Volume at infinite dilution in water also for solutes, such as n-alcohols, forming H bonds with water molecules. Since the packing effects in water are largely related to the small size of its molecules, the latter feature is the ultimate cause of the decrease in partial Molar Volume associated with the hydrophobic effect.
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comment on hydrophobic effects on partial Molar Volume j chem phys 122 094509 2005
Journal of Chemical Physics, 2005Co-Authors: Giuseppe GrazianoAbstract:It is pointed out that the results obtained by Imai and Hirata [ J. Chem. Phys.122, 094509 (2005)] for the partial Molar Volume of benzene in a detailed model of water and in a hypothetical nonpolar water model should be interpreted with care. By turning off the electrostatic interactions among water molecules, keeping fixed the Molar Volume and so the liquid number density, in order to produce the hypothetical nonpolar water without H bonds, the size of water molecules increases from about 2.8 to about 3.2A. This fact is due to the bunching-up effect of H bonds. The consequences of this fact are clarified by means of calculations performed using the analytical expression of the partial Molar Volume derived by Lee [J. Phys. Chem.87, 112 (1983)] from the scaled particle theory equation of state for hard-sphere mixtures.
Donald B Dingwell - One of the best experts on this subject based on the ideXlab platform.
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a partial Molar Volume for la2o3 in silicate melts
Journal of Non-crystalline Solids, 2006Co-Authors: Philippe Courtial, Donald B DingwellAbstract:Abstract The densities of several La-bearing silicate melts distributed along binary joins have been measured using the double-bob Archimedean method. The results show that the addition of La2O3 leads to an increase in the melt density. From these density data, the partial Molar Volume of La2O3 in silicate melts has been determined. Distinct values for partial Molar Volume of La2O3 have been obtained (i.e., 44.01 and 37.04 cm3/mol at 1273 K for the La2O3–Na2O–SiO2 and La2O3–CaO–MgO–Al2O3–SiO2 systems, respectively) indicating a compositional dependence of the partial Molar Volume of La2O3. Nevertheless, a single value for the partial Molar Volume of La2O3 (i.e., 43.47 cm3/mol at 1273 K) suffices to describe the Molar Volume of melts within errors in the entire multi-component system La2O3–Na2O–CaO–MgO–Al2O3–SiO2 and for La2O3 concentrations not greater than 7 mol%. In addition, this work points out that the Molar Volumes behave ideally within the composition range investigated (i.e., linear variation of the Molar Volume along the binary joins). Distinct values for the partial Molar Volume of La2O3 obtained in this study and their differences with the Molar Volumes of molten La2O3 given in the literature raise the possibility however that this ideality is not maintained within the entire system.
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Nonlinear composition dependence of Molar Volume of melts in the CaOAl2O33SiO2 system
Geochimica et Cosmochimica Acta, 1995Co-Authors: Philippe Courtial, Donald B DingwellAbstract:Abstract Density measurements have been performed on nine liquids in the system CaOAl2O3SiO2, in the temperature range of the melting point up to 1800°C, using both Pt- and Ir-based double-bob Archimedean method. In addition, the Molar Volume has been determined at 1800°C for one liquid along the SiO2Al2O3 join. The data of this study show that, within the temperature and the composition range investigated, the Molar Volume of Ca-aluminosilicate melts at low SiO2 content does not behave linearly as function of the composition. This nonideality results clearly from interaction between SiO2 and CaO, whereas our data in addition with literature data suggest that SiO2Al2O3 and CaOAl2O3 interactions could also occur in these Ca-aluminosilicate melts at high Al2O3 content. These different results were analysed using a regression equation from which the partial Molar Volume of each component was obtained by the method of least squares. A nonideal model (SC) for Ca-aluminosilicate melts is thus proposed, involving an excess Volume term between SiO2 and CaO and leading the calculation of the liquids Molar Volume within 0.5% of uncertainties except for Ca- and Al-rich compositions. A better constrain of this model in this extreme composition range requires new data of pure alumina liquid. Some structural implications of this nonideal behaviour with respect to the Molar Volume are also discussed.
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density of some titanium bearing silicate liquids and the compositional dependence of the partial Molar Volume of tio2
Geochimica et Cosmochimica Acta, 1992Co-Authors: Donald B DingwellAbstract:Abstract The densities of thirteen silicate liquids along the Na2SiO3-TiO2 and CaSiO3-TiO2 joins and six other titanium-bearing silicate liquids of the general formula X 2 n n+ TiSiO5 (where X = Li, Na, K, Rb, Cs, Ca, Sr, Ba) have been measured in equilibrium with air using the double Pt bob Archimedean method. The Na2SiO3-TiO2 join was investigated from 10–50 mole% TiO2 in the temperature range 1000–1150°C whereas the CaSiO3-TiO2 join was investigated from 10–80 mole% TiO2 in the temperature range of 1400–1625°C. Density increases with TiO2 content along both joins. Partial Molar Volumes of the binary endmembers, Na2SiO3 and CaSiO3, and of TiO2 have been computed. The partial Molar Volume of Na2SiO3 agrees well with that determined by Bockris et al. (1955). The partial Molar Volume of CaSiO3 is in disagreement with that of Tomlinson et al. (1958). The partial Molar Volume of TiO2 derived from a linear fit to the Na2SiO3-TiO2 join is 27.6(3) cm3/mole at 1150°C. The partial Molar Volume of TiO2 derived from linear extrapolation of the CaSiO3-TiO2 data to TiO2 at 1600°C is 24.3(4) cm3/mole. Comparison of the partial Molar Volume data from these binary joins with TiO2 liquid density data ( Dingwell , 1991) requires the existence of a large positive excess Volume in the Na2SiO3-TiO2 system at 1150°C.
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a partial Molar Volume for b 2 o 3 in haplogranitic melt
Canadian Mineralogist, 1992Co-Authors: Ruth Knoche, Sharon L Webb, Donald B DingwellAbstract:The densitiesa nd thermal expansivitieso f boron-bearingh aplogranitic glassesa nd Iiquids have been determined using a combination of scanning .florimetry and dilatomelry. B2O3 reduces the density of haplogranitic liquids (at 750'C) from 2.295 t 0.006 g cm-r to 2.237 + 0.005 g cm-3 wirh the addition of 8.92 wt. Vo 82o,. These densities have been converted into Molar Volumes in the binary system haplogranite - BrO3. The partial Molar Volume of 8203, calculated from a linear fit to the data at 750oC, is ,10.30 + 0.77 cmr mole-r in these melts. This value compares with a Molar Volume of pure B2O3 at this temperature of M.36 x. 0.22 cm3 mole-l (Napolitano et ol. 1965), indicating a negative excess Volume of mixing along the haplogranite - B2O3 join. In comparison, at l3moc, the addition ot Na2O to B2O3 reduces the panial Molar Volume of B2O3 from 46.6 to 32.3 cm3 mole-r ar 45 molego Na2O (Riebling 1966).T he densityr esultsr eported here, along with the viscosity-reducinge ffect of B2O3o n granitic melts (Dingwell et al, 1992),s hould both significantlya cceleratep rocesseso f crystal-melt fractionation and facilitate the evolution of extremely fractionated igneous systems.
Xiaoyan Ji - One of the best experts on this subject based on the ideXlab platform.
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prediction of Molar Volume and partial Molar Volume for co2 ionic liquid systems with heterosegmented statistical associating fluid theory
Fluid Phase Equilibria, 2012Co-Authors: Xiaoyan Ji, Hertanto AdidharmaAbstract:Abstract To design ionic liquids (ILs) as effective liquid absorbents for CO2 separation from flue or synthesis gases, it is necessary to know the properties and phase equilibria of the CO2/IL systems. The Molar Volumes of CO2/IL mixtures are predicted with the heterosegmented statistical associating fluid theory equation of state. The comparison with the available experimental data shows that the model can be used to predict reliably the Molar Volumes of CO2/IL mixtures from 293 to 413 K and pressures up to 160 bar. In addition, the partial Molar Volume of CO2 in CO2/IL mixtures and the partial Molar Volume of CO2 at infinite dilution in an IL are also predicted.
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Prediction of Molar Volume and partial Molar Volume for CO2/ionic liquid systems with heterosegmented statistical associating fluid theory
Fluid Phase Equilibria, 2012Co-Authors: Xiaoyan Ji, Hertanto AdidharmaAbstract:Abstract To design ionic liquids (ILs) as effective liquid absorbents for CO2 separation from flue or synthesis gases, it is necessary to know the properties and phase equilibria of the CO2/IL systems. The Molar Volumes of CO2/IL mixtures are predicted with the heterosegmented statistical associating fluid theory equation of state. The comparison with the available experimental data shows that the model can be used to predict reliably the Molar Volumes of CO2/IL mixtures from 293 to 413 K and pressures up to 160 bar. In addition, the partial Molar Volume of CO2 in CO2/IL mixtures and the partial Molar Volume of CO2 at infinite dilution in an IL are also predicted.
