The Experts below are selected from a list of 14928 Experts worldwide ranked by ideXlab platform
Reza Safari - One of the best experts on this subject based on the ideXlab platform.
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application of lir in prediction of surface tension and its temperature coefficient of liquid Alkali Metals
Journal of Molecular Liquids, 2008Co-Authors: Nahid Farzi, Reza Safari, Fakhri KermanpourAbstract:Abstract An expression has been derived for radial distribution function (RDF) at contact, g(σ), for a real fluid by the use of linear isotherm regularity (LIR). This expression, which is related to intermolecular interaction, can be used to describe the temperature–density dependency of RDF at contact, g(σ,ρ,T). The expression is used for prediction of surface tension of liquid Alkali Metals in Evan's expression using Lang–Kohn surface energy and in molecular dynamic results for surface tension. Application of some approximation to Evan's expression shows that a correct selection of surface energy in the resultant expression for surface tension yields values that are in good agreement with the experiment. The surface tension of liquid Alkali Metals has been obtained from the molecular dynamic studies using g(σ,ρ,T) and SE/NkB ≈ S2/NkB, where S2 is related to two particle correlations. The calculated surface tension of liquid Alkali Metals is in good agreement with the experimental values. The calculated values of surface tension using g(σ,ρ,T) are in better agreement with the experiment than those of the hard sphere model.
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derivation of structure factor s q and direct correlation function c q of liquid Alkali Metals and simple fluids using the lir
Fluid Phase Equilibria, 2005Co-Authors: Nahid Farzi, Reza SafariAbstract:Abstract Expressions for direct correlation function, C ( Q ), and structure factor, S ( Q ), of liquid Alkali Metals (Na, Rb, Cs) and simple dense fluids (Ar, Kr) have been derived using the linear isotherm regularity (LIR). Unlike previous models, it is shown in this work that C ( Q ) and, consequently, S ( Q ) can be obtained without employing any specific potential; only p-v-T experimental data have been used for the calculation of C ( Q ) and S ( Q ). With these expressions, it is possible to determine the height and position of the first peak of S ( Q ) with an acceptable accuracy. The limiting of S ( Q ) at Q = 0 is calculated and compared with the values obtained experimentally, and those calculated from the extended random phase approximation (ERPA) and random phase approximation (RPA) models. We have used the derived expressions for S ( Q ) of liquid Alkali Metals and simple dense fluids for prediction of the pressure and density derivatives of S ( Q ) in the vicinity of the first peak.
Nahid Farzi - One of the best experts on this subject based on the ideXlab platform.
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application of lir in prediction of surface tension and its temperature coefficient of liquid Alkali Metals
Journal of Molecular Liquids, 2008Co-Authors: Nahid Farzi, Reza Safari, Fakhri KermanpourAbstract:Abstract An expression has been derived for radial distribution function (RDF) at contact, g(σ), for a real fluid by the use of linear isotherm regularity (LIR). This expression, which is related to intermolecular interaction, can be used to describe the temperature–density dependency of RDF at contact, g(σ,ρ,T). The expression is used for prediction of surface tension of liquid Alkali Metals in Evan's expression using Lang–Kohn surface energy and in molecular dynamic results for surface tension. Application of some approximation to Evan's expression shows that a correct selection of surface energy in the resultant expression for surface tension yields values that are in good agreement with the experiment. The surface tension of liquid Alkali Metals has been obtained from the molecular dynamic studies using g(σ,ρ,T) and SE/NkB ≈ S2/NkB, where S2 is related to two particle correlations. The calculated surface tension of liquid Alkali Metals is in good agreement with the experimental values. The calculated values of surface tension using g(σ,ρ,T) are in better agreement with the experiment than those of the hard sphere model.
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derivation of structure factor s q and direct correlation function c q of liquid Alkali Metals and simple fluids using the lir
Fluid Phase Equilibria, 2005Co-Authors: Nahid Farzi, Reza SafariAbstract:Abstract Expressions for direct correlation function, C ( Q ), and structure factor, S ( Q ), of liquid Alkali Metals (Na, Rb, Cs) and simple dense fluids (Ar, Kr) have been derived using the linear isotherm regularity (LIR). Unlike previous models, it is shown in this work that C ( Q ) and, consequently, S ( Q ) can be obtained without employing any specific potential; only p-v-T experimental data have been used for the calculation of C ( Q ) and S ( Q ). With these expressions, it is possible to determine the height and position of the first peak of S ( Q ) with an acceptable accuracy. The limiting of S ( Q ) at Q = 0 is calculated and compared with the values obtained experimentally, and those calculated from the extended random phase approximation (ERPA) and random phase approximation (RPA) models. We have used the derived expressions for S ( Q ) of liquid Alkali Metals and simple dense fluids for prediction of the pressure and density derivatives of S ( Q ) in the vicinity of the first peak.
Liang Chen - One of the best experts on this subject based on the ideXlab platform.
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the poisoning effect of Alkali Metals doping over nano v2o5 wo3 tio2 catalysts on selective catalytic reduction of nox by nh3
Chemical Engineering Journal, 2011Co-Authors: Liang ChenAbstract:Abstract The nano TiO2 supported V2O5–WO3/TiO2 catalysts (VWTi) were prepared by impregnation method assisted with ultrasonic energy. Their poisoning on activity by Alkali Metals (Na, K, Ca and Mg) was investigated. The degree of the poisoning effect for all the Alkali metal doped catalysts was shown as follows: K > Na > Ca > Mg. Further investigations were carried by NH3-TPD, DRIFTS, XPS and H2-TPR characterization. Na and K could decrease the amount and stability of the Bronsted acid sites to a greater extent than Mg and Ca. Surface chemisorbed oxygen could also be reduced and the downward trend was in good agreement with SCR activity. In addition, the reducibility of vanadium species on the Ca and Mg doped catalysts are higher than that on the Na and K doped catalysts with the same Alkali metal oxides loadings. Furthermore, Na and K ions could also affect the reduction degree of tungsten species, while no obvious changes have happened for the tungsten species over Ca- and Mg-VWTi catalysts. Consequently, the different poisoning effects of these four Alkali Metals doped nano V2O5–WO3/TiO2 catalysts are correlated not only to the surface acidity but also to the reducibility of vanadium and tungsten species.
Kaisung Wang - One of the best experts on this subject based on the ideXlab platform.
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inhibition and promotion the effect of earth Alkali Metals and operating temperature on particle agglomeration defluidization during incineration in fluidized bed
Powder Technology, 2009Co-Authors: Shihhsien Chang, Kaisung WangAbstract:Abstract Some studies have demonstrated that earth Alkali Metals promote agglomeration; however, others have shown that they inhibit the generation of agglomeration. The earth Alkali Metals (Mg and Ca) may cause both inhibition and promotion of agglomeration/defluidization. Therefore, this study focuses on the effect of Mg, Ca and the operating temperature on the agglomeration/defluidization of sodium during incineration in a fluidized bed reactor. The results indicate that the added Mg and Ca inhibit agglomeration and increase the defluidization time. At low Na/Mg and Na/Ca mole ratios, Mg and Ca inhibit defluidization significantly. However, the inhibition reduces as the concentration of Na increases. When the mole ratio (Na/Mg and Na/Ca) exceeds two, the inhibition of Mg and Ca is not apparent. Under these conditions, the operation temperature is the main factor with regard to agglomeration/defluidization. When Mg and Ca are added to reduce the agglomeration/defluidization, both the concentration of Na and operating temperature must be considered.
Thomas Heine - One of the best experts on this subject based on the ideXlab platform.
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tuning the electronic structure of graphene through Alkali metal and halogen atom intercalation
Solid State Communications, 2018Co-Authors: Sohail Ahmad, Pere Miro, Martha Audiffred, Thomas HeineAbstract:Abstract The deposition, intercalation and co-intercalation of heavy Alkali Metals and light halogens atoms in graphene mono- and bilayers have been studied using first principles density-functional calculations. Both the deposition and the intercalation of Alkali Metals gives rise to n-type doping due to the formation of M+-C- pairs. The co-intercalation of a 1:1 ratio of Alkali Metals and halogens derives into the formation of ionic pairs among the intercalated species, unaltering the electronic structure of the layered material.