Computational studies on physico-chemical properties in the quality analysis of corn and peanut oil

Oils are commonly used in cooking as a frying medium which has been constantly subjected to different levels of heating. In this work, we have considered the most commonly used oils namely peanut oil and corn oil. Quality analyses of corn and peanut oils were made by relating macroscopic properties (ultrasonic velocity, viscosity, and density) to microscopic parameters (intermolecular free length, adiabatic compressibility etc.,) by subjecting them to six cycles of heating (190 ˚C). Variation in the mentioned property indexes, the degree of degradation and reusability for the next heating cycle that could be used in the food industry and processing were monitored. Using Newton-Laplace and Wood’s equation, the adiabatic compressibility, acoustic impedance, and intermolecular free length of the oil were estimated from the experimental data. Ultrasonic velocity was observed linearly as related to viscosity with the dependency factor (R2 = 0.932). With the aid of experiential data, the physical thermodynamic parameters, particularly particle size, packing factor, chemical potential, and L-J potential were computed. A high correlation factor was observed by fitting ultrasonic velocity, viscosity, and density to Parthasarathy and Bakshi, and Rodenbush equations. In the study, ultrasonic velocity, a macroscopic parameter, could be decoded to determine the microscopic variations in oil subjected to different temperatures in an industrial application.

THERMO PHYSICAL PROPERTIES OF TERNARY MIXTURES OF 1-HEXANOL/1- OCTANOL CONTAINING N-N-DIMETHYLFORMAMIDE AND TOLUENE AT 303.15 K

In the present work, ultrasonic velocity (u), viscosity (η) and density (ρ) of ternary mixtures of 1-hexonal and 1-octanol with dimethylformamide in toluene at 303.15 K have been measured over the entire composition range. From the experimental data, acoustical parameters such as adiabatic compressibility (β), intermolecular free length (L ), free volume (V ), acoustic impedance (Z), excess adiabatic compressibility , excess free length , excess free f f E E (b ) (L )f volume and excess acoustic impedance have been computed. The variation of these properties with composition are E E (V ) (Z ) f discussed in terms of molecular interactions between unlike molecules of the mixtures.

Ultrasonic Study of Molecular Interactions and Compressibility Behaviour of Samarium Soaps in Benzene-DMSO Mixture

Ultrasonic measurements of samarium soaps (palmitate and myristate) have been carried out in a mixture of benzene and DMSO (70%-30% v/v) to determine the critical micellar concentration(CMC), soap-solvent interaction and various acoustic parameters. The results show that ultrasonic velocity, intermolecular free length, adiabatic compressibility, adiabatic molar volume and apparent molar compressibility decrease while specific acoustic impedance, relative association and solvation number increase with increase in soap concentration. The results of ultrasonic measurements have also been explained in terms of well-known equations. Keywords: Ultrasonic measurements, molecular interactions, samarium soaps, compressibility, critical micellar concentration(CMC).

Study of thermo-acoustical properties of Liquid mixtures of Aqueous solution of Lithium Chloride and Lithium Hydroxide at Different Temperatures

Density, viscosity and ultrasonic velocity of the various compositions of liquid mixtures of aqueous solutions of Lithium chloride (LiCl) and Lithium hydroxide (LiOH) have been experimentally measured at 303,308,313 and 318K and at atmospheric pressure. From these experimental measurements the acoustic impedance (Z) and adiabatic compressibility (ad) have been calculated. The variations in these parameters have been correlated to derive the intermolecular interactions taking place between the mixtures of present study.

Adiabatic compressibility of biphasic salt melts

The adiabatic compressibility along the two-phase saturation line was calculated for nine molten immiscible mixtures, namely, LiF + KBr, LiF + CsCl, LiF + RbBr, LiF + KI, LiF + CsBr, LiF + RbI, LiF + CsI, LiCl + AgBr, and NaCl + AgI, using experimental data on the sound velocity and density. It is shown that the ratio of compressibility of the equilibrium phases depends significantly on the sizes of the mixed ions. The dependence of the changes in compressibility in the distance and in the vicinity of the critical mixing point on the characteristics of the chemical bond between the ions is discussed.

Study of Molecular interaction in Binary Mixtures containing N, N-Dimethylformamide and n-Butanol

The acoustic studies of the interactions between alcohol molecules and water soluble polar solvent DMF are significant for understanding the relationships between structure and function of polar molecule like DMF, and for explaining the mechanisms of interaction of alcoholic OH group with an electronegative moiety. In this piece of work Ultrasonic velocity, density and viscosity have been measured at 298 K, 308 K, 318 K and 328 K for mixture of N,N-dimethylformamide (DMF) and n-butanol, the frequency being maintained at a constant value. The experimental data have been used to calculate the acoustical and thermodynamical parameters like adiabatic compressibility, free length, free volume, internal pressure, acoustic impedance, Gibbs free energy

Ultrasonic Investigation of Binary Solutions of Petrolium And Its Products

<p>Experiment values of densities and ultrasonic speed of petroleum product Gasoline (Petrol) and 2T Oil were taken in different volume concentrations from 5%, 10%------, and 95% at different temperatures from 298.15K to 318.15K having difference of 5K. From the experimental data, Apparent Molar Compressibility (<em>ϕ_K</em>), Relative Association (<em>R_A</em>), Solvation Number (<em>S_n</em>), Free Energy of Activation (<em>ΔE</em>), Excess Adiabatic Compressibility (<em>β_ad^E</em>), Excess Volume (<em>V^E</em>), Excess Free Length (<em>L_f^E</em>) have been computed. These parameters are used to focus light on the nature of component molecules of binary liquids and the excess functions are found to be sensitive to the nature and extent of the intermolecular interactions taking place in these binary mixtures.</p>

Automatic Measurement of the Dependence on Pressure and Temperature of the Mass Density of Drilling Fluids

Drilling fluids are subjected to large variations of pressure and temperature while they are circulated in a well. This span of pressures and temperatures is so large that the mass density of the drilling mud differs from one depth to another. For a precise estimation of the hydrostatic and hydrodynamic pressures, it is therefore important to have a good estimation of the pressure and temperature dependence of the mass density of drilling fluids. Usually, the mass density of drilling fluids is manually measured with a mud balance. The pressure and temperature dependence of the mass density of the fluid, i.e. its PVT behavior, is then estimated based on the PVT behavior of its components and their relative proportions. However, variations in the composition of the fluid mix and uncertainties on the PVT behavior of each components, may lead to inaccuracies. To circumvent these limitations, an apparatus that measures directly and automatically the PVT behavior of the drilling fluid contained in a pit has been designed. The setup measures both the mass density and the speed of sound in the fluid at specific conditions of pressure and temperature. From the speed of sound in the liquid mix, it is possible to estimate the adiabatic compressibility. The device also utilizes a heat exchanger from which the thermal conductivity and specific heat capacity of the drilling fluid can be estimated. Combining the specific heat capacity, thermal conductivity and the adiabatic compressibility, the isothermal compressibility can be calculated. By combining measurements made at different conditions of pressure and temperature, a PVT model of the drilling fluid is estimated. By providing automatically, and on a continuous basis, the actual PVT behavior of drilling fluids, drilling automation systems can gain in precision and at the same time, their configuration can be simplified, therefore making them more accessible to any drilling operation.

Acoustic, thermal and optical properties of organic based disodium tartrate salt

In this work, acoustic, thermal, and optical properties were tested on the different concentrations of the Disodium Tartrate solutions. First, the viscosity studies were analyzed for the Disodium tartrate in the concentration range from 2% to 20% with different temperatures 303K, 308K, 313K, and 318K. It was noted that the relative viscosity and the activation energy of the prepared compound increase with increases in concentration and decreases with temperature increases. The properties like density and ultrasonic velocity are varied when increases the concentration of the aqueous solutions of Disodium Tartrate. In this study, the values of adiabatic compressibility show an inverse behavior when compared with ultrasonic velocity due to the interaction between solute and solvent molecules. Also observed that the inter-molecular free length is maximum for a lower percentage. The free volume for the compound is maximum at 2% and a minimum of 20%, since it reduces when the internal pressure increases. It was revealed that the classical absorption coefficient and relaxation time for Disodium Tartrate is minimum for lower percentage and minimum for a higher percentage. The interactions between the solute and solvent are confirmed through the property like specific Acoustical impedance. It was noted that the increase in internal pressure increases the concentration of the compound. The ion-solvent interaction was discussed by the relative association study, thus the values of relative association increases with an increase in concentration. The Rao’s and Wada’s constant increases linearly in aqueous solutions of Disodium Tartrate for the entire system.

Acoustical Parameters of Polyvinyl Alcohol

Ultrasonic investigation provides a wealth of information in understanding the intermolecular interaction of solute and solvent. An attempt has been made to measure density, viscosity and ultrasonic velocity of aqueous solution of polyvinyl alcohol of molecular weight approximately 140,000 at different temperatures 35οC, 40oC, 45οC, 50oC, 55οC, 60oC, 65οC at 0.8% concentration. Ultrasonic velocity is measured using ultrasonic interferometer at 1 MHz frequency. The acoustical parameters like, adiabatic compressibility, acoustic impedance, intermolecular free length and relaxation time have been calculated at different temperatures. These parameters were used to understand the behaviour of solute and solvent.