Physical Acoustics

"Thermo-acoustic investigations of the non linear properties of fructose in aqueous solution of NaCl and MgCl2 have been
done in the temperature range, 298.15K - 308.15K at various concentrations using volume expansivity data. Several nonlinear parameters such as Moelwyn-Hughes parameter (C1), Bayer’s non-linear parameter (B/A), reduced volume( ), reduced isothermal bulk modulus (â),Sharma’s constants (S0, S*, S*0), Huggins parameter (F), isobaric acoustical parameter (K), isochoric acoustical parameter (K”), isothermal acoustical parameter(K’), fractional free volume(f), repulsive exponent (ç), reduced volume expansivity (a*), internal pressure (Pi), cohesive energy density (âi), critical temperature (T*) and thermo-acoustical parameter such as A* and B* have been studied. The non-linearity behavior of these parameters has been explained in terms of the concentration and thermal changes in the systems under investigation. The present analysis provides a deep insight about the nature and types of interactions prevalent in the solutions of electrolytes and fructose. The obtained results provide a reliable basis to understand the action of electrolytes and bio-molecules in the bio-chemical processes undergoing in a bio-physical system."

"Thermo-acoustic investigations of polymer solutions of Hydroxyl-terminated polybutadiene (HTPB) and Chlorobenzene, in the temperature range of 303 K to 323 K, have been done using ultrasonic velocity and density data taken from literature. Various acoustical parameters such as molar sound velocity, molar adiabatic compressibility, acoustic impedance, van der Waal’s constants, free volume, internal pressure, and cohesive energy have been determined. A large number of thermo-dynamical parameters such as available volume, geometrical volume, space filling factor, intermolecular free length, relative association, surface tension, refractive index, molar refraction, pseudo-Gruneisen parameter and Debye temperature have been evaluated.
Schaaff’s Collision Factor Theory, Nomoto’s relation, Vandeal-Vangeel relation, Impedance dependent relation and Ideal mixing relation have been used to predict the values of ultrasonic velocities in the systems under study, within the temperature range  303 K - 323 K. The obtained results have been compared with the experimental results as available in literature. Several Excess parameters e.g. Excess Adiabatic Compressibility (KSE), Excess Isothermal Compressibility (KTE), Excess Intermolecular Free Length (LfE), Excess free volume (VfE), Excess Internal Pressure (PiE), Excess Wada’s Constant (WE), Excess Rao’s Constant (RE) and Excess pseudo-Gruneisen parameter (rE), have also been evaluated at several compositions of the polymer solutions in the temperature range under investigation. The variations of thermo-acoustic parameters of the polymer solution provide a deep insight into the nature, type and strength of inter molecular interactions prevalent in it. The non-ideal behavior of the solution has been explained in terms of the composition and temperature dependence of its acoustical and thermo-dynamical parameters.
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Intermolecular interaction studies of Trans- 4- cyano cinnamic acid ester have been done over the temperature range 340 K to 393 K, using ultrasonic velocity and density data taken from literature. Several acoustical parameters such as adiabatic compressibility, isothermal compressibility, acoustic impedance, van der Waal’s constants, molecular radius, space filling factor,
surface tension, pseudo- Gruneisen parameter, Debye temperature, enthalpy and Poisson’s ratio have been determined. Various thermo-dynamical parameters such as available volume, refractive index, molar refraction, Eykmann constant, internal
pressure, intermolecular free length and relative association have also studied. Free Length Theory and Collision Factor Theory
have been applied to predict the ultrasonic velocity values in the system. The obtained results has been explained in terms of the temperature dependence of theses parameter and the intermolecular interaction present in the system, The present investigation provide a rich source of information about the type and extent of molecular interaction occurring in the liquid crystal. "

This short theoretical work discusses some problems of finding of the suitable eigenvalues and eigenvectors. The eigenvalues and eigenvectors represent the solutions of the coupled equations of motion written in the well-known tensor form. These coupled equations of motion describe shear-horizontal (SH) wave propagation in the transversely isotropic piezoelectromagnetic materials of class 6mm when the SH-wave propagation is coupled with both the electrical and magnetic potentials. It is stated that as many as six eigenvalues can be soundly found for the problem. The problem is that some eigenvalues result in the corresponding certain eigenvectors and some eigenvalues allow existence of uncertain eigenvectors that can be chosen by a researcher. This uncertainty allows researchers to choose several certain forms for the uncertain eigenvectors. It is discussed that the author of this report has used the certain forms for the uncertain eigenvectors that are naturally coupled with the ce...