Partial Molar Volumes,Viscosity B-Coefficients,and Adiabatic Compressibilities of Sodium Molybdate in Aqueous 1,3-Dioxolane Mixtures from 303.15 to 323.15 K

Partial molar volumes () and viscosity B-coefficients of sodium molybdate in 1,3-dioxolane + water mixtures have been determined from solution density and viscosity measurements at 303.15, 313.15, and 323.15 K and at various electrolyte concentrations. Also, the adiabatic compressibility of different solutions has been determined from the measurement of sound speeds at 303.15 K. The experimental density data were evaluated by the Masson equation, and the derived parameters were interpreted in terms of ion–solvent and ion–ion interactions. The viscosity data have been analyzed using the Jones–Dole equation, and the derived parameters, B and A, have also been interpreted in terms of ion–solvent and ion–ion interactions, respectively. The structure- making or breaking capacity of the electrolyte under investigation has been discussed in terms of the sign of . The compressibility data obtained from sound speeds of different solutions indicate the electrostriction of the solvent molecules around the ions.     

Viscosity Measurements and Correlation of the Squalane + CO<Subscript>2</Subscript> Mixture

Experimental results for the viscosity of squalane + CO₂ mixtures are reported. The viscosities were measured using a rolling ball viscometer. The experimental temperatures were 293.15, 313.15, 333.15, and 353.15 K, and pressures were 10.0, 15.0, and 20.0 MPa. The CO₂ mole fraction of the mixtures varied from 0 to 0.417. The experimental uncertainties in viscosity were estimated to be within ±3.0%. The viscosity of the mixtures decreased with an increase in the CO₂ mole fraction. The experimental data were compared with predictions from the Grunberg–Nissan and McAllister equations, which correlated the experimental data with maximum deviations of 10 and 8.7%, respectively.     

Densities and Refractive Indices of Binary Mixtures of Benzene with Triethylamine and Tributylamine at Different Temperatures

Experimental densities, ρ, and refractive indices, n _D for binary liquid mixtures of benzene with triethylamine (TEA) and tributylamine (TBA) have been measured as a function of composition in the temperature range from 278.15 to 318.15 K. The excess molar volume, V ^E , and its temperature dependence, dV ^E /dT for the binary mixtures were calculated using the experimental data. The values of V ^E for the mixtures were also estimated by using the Flory statistical theory and refractive index.     

Density,Viscosity, and Surface and Interfacial Tensions of Mixtures of Water + <Emphasis Type="Italic">n</Emphasis>-Butyl Acetate + 1-Propanol at 303.15 K and Atmospheric Pressure

Experimental densities, viscosities, and surface and interfacial tensions have been measured at 303.15 K for liquid mixtures of water + n-butyl acetate + 1-propanol. The excess molar volume, V ^E, viscosity, η, and surface tension, γ, were calculated and rational functions due to Myers and Scott, and Pando et al. were used to describe the composition dependence of these properties. The viscosity, η, of the mixtures was correlated using a theoretically based method developed from the Eyring theory using the above-mentioned rational functions to express the excess Gibbs energy of activation for viscous flow, G ^≠E. The UNIMOD model based on the Eyring theory was used to correlate the viscosity of the binaries and to predict the same property for ternary mixtures. To describe the above-mentioned properties of the ternary system, binary pair additivity and some empirical models were considered. The methods of Fu et al. and Li et al. were used to correlate the binary surface tension and also to predict the ternary behavior. The interfacial tension was correlated by the Li and Fu method.     

Solute–Solvent and Solute–Solute Interactions of Resorcinol in Mixed 1,4-Dioxane–Water Systems at Different Temperatures

The densities, viscosities, and ultrasonic speeds of resorcinol in 1,4-dioxane + water mixtures and in pure 1,4-dioxane have been measured at 303.15, 313.15, and 323.15 K. Apparent molar volumes (V_ϕ) and viscosity B-coefficients are obtained from these data supplemented with densities and viscosities, respectively. The limiting apparent molar volumes ( ) and experimental slopes ( ) derived from the Masson equation have been interpreted in terms of solute–solvent and solute–solute interactions, respectively. The viscosity data have been analyzed using the Jones–Dole equation, and the derived parameters B and A have also been interpreted in terms of solute–solvent and solute–solute interactions, respectively. The structure making/breaking capacities of resorcinol in the studied solvent systems have been discussed. The compressibilities obtained from the data supplemented with their ultrasonic speeds indicate the electrostriction of the solvent molecules around the ions     

The bulk viscosity in dense fluids

Method for calculating bulk viscosity is described. This method relies on the results of the revised Enskog theory for hard-sphere fluid mixtures and the use of the temperature and density-dependent diameter of Mansoori-Canfield and Rasaiah-Stell to model each species of the real mixtures. Using this method the predicted values of the bulk viscosity of several mixtures of hydrocarbons and noble gases were calculated. These results are mainly predictive.     

Study on Solution Properties of Binary Mixtures of Some Industrially Important Solvents with Cyclohexylamine and Cyclohexanone at 298.15 K

Densities and viscosities were measured for the binary mixtures of cyclohexylamine and cyclohexanone with butyl acetate, butanone, butylamine, tert-butylamine, and 2-butoxyethanol at 298.15 K over the entire composition range. From density data, the values of the excess molar volume (V ^E) have been calculated. The experimental viscosity data were correlated by means of the equation of Grunberg–Nissan. The density and viscosity data have been analyzed in terms of some semiempirical viscosity models. The results are discussed in terms of molecular interactions and structural effects. The excess molar volume is found to be either negative or positive depending on the molecular interactions and the nature of the liquid mixtures and is discussed in terms of molecular interactions and structural changes.     

Measurements of the Liquid Viscosities of Mixtures of n-Butane, n-Hexane, and n-Octane with Squalane to 30 MPa

The viscosities of liquid mixtures of n-butane, n-hexane, and n-octane with squalane that represent model mixtures of refrigerants with refrigeration oil were measured at temperatures between 273.15 and 333.15 K, and at pressures from 0.1 to 30 MPa, by using a falling body viscometer. The uncertainty of the measurements was estimated to be no larger than 2.9%. The experimental viscosity values were fitted to a Tait-like equation within 2.8%. There are larger deviations between the experimental data and calculated values predicted by the equation of Kanti et al., which is derived from the Flory theory. By introducing an interaction parameter of the energetic mixing rule into the equation, the deviations were significantly reduced.     

Optimization of stress–strain behavior parameters by genetic algorithms method: Application to soft-matrix two-phase alloys

 Deformation behavior of soft-matrix two-phase alloys has been computed using a continuum mechanics model based on an Isostrain condition, while the stress is distributed by the rule of mixtures. A genetic algorithm (GA) was used to optimize the mechanical modeling parameters such as the resistance and the formability of each phase. The stress–strain curves have been calculated as a function of volume fraction and mechanical properties of phases. The calculated and experimental stress–strain curves are compared and good agreement is found. The resistances increases with the rise of the hard phase volume fraction; this is more important with the presence of the hard phase than with the soft one. A linear law of variation of the phase resistance allows to interpolate and extrapolate the model, a good agreement is found with the evolution of the mechanical behavior. Received: 30 July 2002 / Accepted: 10 December 2002     

Generalization and calculation of the thermal diffusion factor of binary hydrogen-containing gaseous mixtures

The results of generalization of experimental data on the thermal diffusion factor α _T of hydrogen-containing gaseous mixtures within the framework of similarity theory have been given. The calculated relation which makes it possible to predict the thermal diffusion factor of hydrogen-containing mixtures of nonpolar gases with a limited body of data on the substance has been obtained. The α _T values of mixtures of hydrogen with inert gases, including radon Rn, and with N₂, SiH₄, and GeH₄ in the temperature interval 100–1500 K have been calculated.     

High-Pressure (up to 140 MPa) Dynamic Viscosity of the Methane+Decane System

The dynamic viscosity of n-decane and methane mixtures containing 31.24, 48.67, 60.00, 75.66 and 95.75% (mol%) of methane has been measured using a falling-body viscometer. The measurements (295 data points) have been performed in the temperature range 293.15 to 373.15 K and at pressures up to 140 MPa for viscosity. The data have been used to calculate the excess activation energy of viscous flow using a mixing law. Moreover, a self-referencing model, previously developed in the laboratory, gives an average absolute deviation of the viscosity of about 3% with a maximum deviation of 16%.     

Viscosity of Gaseous Mixtures of HFC-125+HFC-32

This paper reports experimental results for the viscosity of gaseous mixtures of HFC-125 (pentafluoroethane)+HFC-32 (difluoromethane). The measurements were carried out with an oscillating-disk viscometer of the Maxwell type at temperatures from 298.15 to 423.15K. The viscosity was measured for three mixtures (mole fraction of HFC-125 is 0.7498, 0.4998, or 0.2475). The viscosity at normal pressure was analyzed with the extended law of corresponding states developed by Kestin et al. and the scaling parameters were obtained for unlike-pair interactions between HFC-125 and HFC-32. The modified Enskog theory developed by Vesovic and Wakeham was applied to predict the viscosity for the binary gaseous mixtures under pressure. For the calculation of the pseudo-radial distribution function in mixtures, a method based on the Carnahan–Starling equation for the radial distribution function of hard sphere mixtures is proposed.     

Empirical and Semi-theoretical Methods for Predicting the Viscosity of Binary <Emphasis Type="Italic">n</Emphasis>-Alkane Mixtures

In this study, empirical and semi-theoretical methods for predicting the viscosity of binary mixtures of n-alkanes are presented at atmospheric pressure and in the temperature range from 288 to 333 K. In the empirical viscosity calculation method, a modified version of the Andrade equation and a simple mixture rule are used. The proposed semi-theoretical method employs both the Enskog’s hard-sphere theory for dense fluids and the principle of corresponding states. The viscosities of binary mixtures of n-heptane with n-hexane and n-nonane covering different compositions were calculated using these methods which require only critical properties and the normal boiling point as input data. The predictions were compared with accurate experimental data in the literature. Highly satisfactory results were obtained. The percent average absolute deviations amount to 1.2 and 0.9% utilizing the empirical and semi-theoretical viscosity methods, respectively, for 27 data points. Paper presented at the Fifteenth Symposium on Thermophysical Properties, June 22–27, 2003, Boulder, Colorado, U.S.A.     

Young’s modulus of cast HMS 2112-C f composite—prediction and ultrasonic evaluation

Various models for the prediction of strengthening mechanism of metal matrix composites (MMCs) containing either fibres or particulates are analysed. Assuming that the matrix strengthening by dislocations could be treated as equivalent to the effect of different volume fraction of dispersoids, as well as by considering the effect of morphology of reinforcement on the Young’s modulus, an expression for Young’s modulus for MMCs has been derived. The Young’s modulus values thus predicted, using this model, have been validated by ultrasonically-derived values of Young’s modulus of an Al-alloy matrix composite containing 5, 8 and 12 wt% chopped carbon fibre (C _f) dispersoids, in as cast and extruded conditions. Further, the theoretically- and ultrasonically-derived Young’s modulus of cast Al-alloy-C _f composites with 5 and 8 wt%C _f have been found to be comparable with the reported values of Young’s modulus for these weight fractions.     

Viscosity of Some Binary Mixtures of Arenes

The viscosity of 12 binary mixtures of benzene+toluene, +ethylbenzene, +isopropylbenzene, +tert-butylbenzene; toluene+ethylbenzene, +isopro- pylbenzene, +tert-butylbenzene; ethylbenzene+isopropylbenzene; isopropylbenzene+tert-butylbenzene; o-xylene+m-xylene; m-xylene+p-xylene; and p-xylene+o-xylene has been measured over the entire range of composition. The viscosity deviations and excess Gibbs energy of activation G ^*E of viscous flow based on Eyring's theory have been calculated. The results have been analyzed in terms of the change in the structure of pure component molecules. The viscosity data have been correlated with the equations of Grunberg and Nissan; Hind, McLaughlin, and Ubbelohde; Tamura and Kurata; Katti and Chaudhri; McAllister; and Heric and Brewer. The Prigogine–Flory–Patterson– Bloomfield–Dewan (PFPBD) theory has been applied to analyze the excess viscosity of the present binary mixtures.     

Measurements of the Liquid Viscosities of Mixtures of Isobutane with Squalane to 30 MPa

The viscosities of liquid mixtures of isobutane with squalane, which seem to be representative of mixtures of refrigerants with refrigeration oil, were measured from 273.15 to 333.15 K at pressures to 30 MPa using a falling-body viscometer. The uncertainty of the measurements was estimated to be no larger than 2.9%. The experimental viscosity values were fitted with a Tait-like equation within 2.8%. There are large deviations between the experimental data and calculated values predicted by the equation of Kanti et al., which is derived from Flory’s theory. By introducing two index numbers of the energetic mixing rule into the equation, the predictions could be improved considerably.     

Viscosity of Al–Cu liquid alloys: measurement and thermodynamic description

In the present work a high temperature oscillating cup viscometer has been used to measure the viscosities of liquid binary Al–Cu alloys. The dependence of viscosity on temperature is well described by the Arrhenius law. For constant temperature, the viscosity as a function of copper concentration exhibits a maximum at a mole fraction x _Cu = 0.7. This might be due to a pronounced chemical short range order in the liquid phase at this composition. As the comparison of existing phenomenological models describing viscosity as a function of composition to the experimental data is unsatisfactory, a new model for the viscosity has been developed within this work based only on a few assumptions and using the enthalpy of mixing as input parameter which is easily accessible. The agreement between model calculation and experimental data is excellent.     

Solubility and viscosity of refrigerant/lubricant mixtures: hydrofluorocarbon/alkylbenzene systems

Alkylbenzenes have been found to be applicable in refrigeration systems with hydrofluorocarbons (HFCs). However, little thermophysical property data for HFC/alkylbenzene mixtures have been reported. In this study, the solubility of HFCs in alkylbenzenes, and the viscosity of HFC/alkylbenzene mixtures were measured. The solubility data were correlated with a cubic equation of state with a single adjustable parameter. The viscosity data were correlated with an empirical equation with a simple mixing rule. The solubility of HFCs in alkylbenzenes and viscosity of these mixtures may be predicted with these models.