Viscosities and ultrasonic speeds of binary mixtures of benzene with triethylamine and tributylamine at different temperatures:An experimental and theoretical study

The viscosities, η, and ultrasonic speeds, u, of pure benzene, triethylamine, （TEA） tributylamine, （TBA）, and those of their binary mixtures, with benzene as common component, covering the whole composition range have been measured at 278.15 K, 283.15 K, 288.15 K, 293.15 K, 298.15 K, 303.15 K, 308.15 K, 313.15 K, and 318.15 K. From the experimental data the deviations in viscosity, △η, deviations in Gibbs free energy, AG, deviations in ultrasonic speed, △u, deviations in entropies, △S^＊, and deviations in enthalpies, △H^＊, of activation of viscous flow have been determined. The sign and magnitude of these parameters were found to be sensitive towards interactions prevailing in the studied systems. Further, the excess molar volumes, VE, were calculated using data for the binary mixtures. Moreover, theoretical values of viscosities and ultrasonic speeds of the binary mixtures were calculated using different empirical relations and theories. The results were in experimental and theoretical values. discussed in terms of average deviations （AD）

Ultrasonic Studies of 4-Aminobutyric Acid in Aqueous Salbutamol Sulphate Solutions at Different Temperatures

Ultrasonic speeds of 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·kg^-1 aqueous salbutamol sulphate（SBS） solutions are measured at 308.15,313.15 and 318.15 K.Isentropic compressibility kS,change in isentropic compressibility△k S,relative change in isentropic compressibility（ △kS /kS^0） ,apparent molal compressibility kφ,limiting apparent molal compressibility kφ^0 ,transfer limiting apparent molal compressibility k φ^0,hydration number nH,pair and triplet interaction parameters kAS,kASS are estimated.The above parameters are used to interpret the solute-solute and solute-solvent interactions of 4-aminobutyric acid in the aqueous salbutamol sulphate solutions.

Improved ultrasonic differentiation model for structural coal types based on neural network

In order to solve the difficulty of detailed recognition of subdivisions of structural coal types,a differentiation model that combines BP neural network with an ultrasonic reflection method is proposed.Structural coal types are recognized based on a suitable consideration of ultrasonic speed,an ultrasonic attenuation coefficient,characteristics of ultrasonic transmission and other parameters relating to structural coal types.We have focused on a computational model of ultrasonic speed,attenuation coefficient in coal and differentiation algorithm of structural coal types based on a BP neural network.Experiments demonstrate that the model can distinguish structural coal types effectively.It is important for the improved ultrasonic differentiation model to predict coal and gas outbursts.

Study of intermolecular interactions in binary mixtures of methyl acrylate with benzene and methyl substituted benzenes at different temperatures:An experimental and theoretical approach

The ultrasonic speeds,u and viscosities,ηof the binary mixtures of methyl acrylate with benzene,toluene,o-xylene,m-xylene,p-xylene,and mesitylene over the whole mole fraction range were measured at six different temperatures and at atmospheric pressure.From the experimental data,the excess isentropic compressibility,κ_(s)^(E),excess ultrasonic speed,u^(E),excess molar isentropic compressibility,K_(s,m)^(E),excess specific impedance,Z^(E)and deviations in viscosity,Δηhave been calculated.The partial molar isentropic compressions,K_(s,m,1) and K_(s,m,2),and excess partial molar isentropic compressions,K_(s,m,1)^(-E) and K_(s,m,2)^(-E) over the whole composition range,partial molar isentropic compressions,K_(s,m,1)^(-)and K_(s,m,2)^(-),and excesspartial molar isentropic compressions,K_(s,m,1)^(-E) and K_(s,m,2)^(-E)of the components at infinite dilution have also been calculated.The results specified the existence of weak interactions between unlike molecules,and these interactions follow the order:benzene>toluene>p-xylene>m-xylene>o-xylene>mesityle ne.The magnitude of interactions was found to be dependent on the number and position of the methyl groups in these aromatic hydrocarbons.

Insight into solute-solute and solute-solvent interactions of semicarbazide hydrochloride in water and D-glucose/D-sucrose+water solutions at temperatures(293.15 to 318.15)K

The solute-solute and solute-solvent interactions of drug semicarbazide hydrochloride with carbohydrates(Dglucose/D-sucrose)are investigated by using volumetric,viscometric and acoustic properties.The measurements of the densitiesρ,ultrasonic speeds u,and viscositiesη.of semicarbazide hydrochloride in 5% and 10%D-glucose/D-sucrose+water(w/w)solutions were carried out at temperatures(293.15-318.15)K and at pressure,p=101 kPa.The apparent molar volumes,Vϕ,limiting apparent molar volumes,V°ϕ,apparent molar compressibilities,Ks,ϕ,limiting apparent molar compressibilities,K°s;ϕ,partial molar expansibilities,E°ϕ,transfer volumes,V°ϕ;tr and transfer compressibilities,K°s;ϕ;tr have been calculated from the experimental data.The viscosity data were examined by using the Jones-Dole equation and the viscosity A and B coefficients were evaluated.The results are discussed in terms of solute-solute and solute-solvent interactions in these solutions.The structure making/breaking ability of semicarbazide hydrochloride is examined using the sign of temperature derivative of Bcoefficient,dB/dT.