The Pressure decay of ethylene due to diffusion into the stagnant liquid of N-methyl-2-pyrrolidone (NMP) is evaluated at temperatures of 278. 15, 298. 15, and 328. 15 K, and at three initial Pressures of about 0. 6, 0. 8, and 1. 1 MPa. Then, an available graphical method named the initial model is implemented to calculate the diffusion coefficient. Some corrections on the initial model are applied as follows: 1) in the infinite series of the solution to Fick’s second law, more terms are considered. 2) the equilibrium Pressure is considered a tuning parameter to eliminate the requirement for an inaccurate experimental measurement. The proposed model is proven to be more reliable and valid for a whole range of Pressure decay data including the early times. Due to the large differences between the results of the initial and the proposed models, the Wilke-Chang relation is considered a basis for comparison. This comparative study shows that the results of the Wilke-Chang relation are more compatible with the proposed model.

In this paper we investigate the fluid flow through a thin (or long) channel filled with a fluid saturated porous medium. We are motivated by some important applications of the porous mediumflow in which the viscosity of fluids can change significantly with Pressure. In view of that, we consider the generalized Brinkman’s equation which takes into account the exponential dependence of the viscosity and the drag coefficient on the Pressure. We propose an approach using the concept of the transformed Pressure combined with the asymptotic analysis with respect to the thickness of the channel. As a result, we derive the asymptotic solution in the explicit form and compare it with the solution of the standard Brinkman’s model with constant viscosity. To our knowledge, such analysis cannot be found in the existing literature and, thus, we believe that the provided result could improve the known engineering practice.

In this paper, a numerical model is used to analyze an optical absorption coefficient according to the electronic properties of InGaN/GaN multiple-quantum-well solar cells (MQWSC) under hydrostatic Pressure. Finite difference techniques have been used to acquire energy eigenvalues and their corresponding eigenfunctions of InGaN/GaN MQWSC and the hole eigenstates are calculated via a 6 6 k. p method under the applied hydrostatic Pressure. All symmetry-allowed transitions up to the fifth subband of the quantum wells (multi-subband model) and barrier optical absorption, as well as the linewidth due to the carrier-carrier and carrier-longitudinal optical (LO) phonon scattering, are considered here. A change in the Pressure up to 10 GPa increases the intraband scattering time up to 38fs and 40fs for light and heavy holes, respectively, raises the height of the Lorentz function and reduces the excitonic binding energy. The multi-subband model has a positive effect on the optical absorption coefficient and increases it by %17, contrary to the Pressure function.

In this research, an apparatus was made and utilized to determine the friction coefficient of chickpea grains on steel surfaces. Experiments were carried out on two black and galvanized surfaces and at four sliding velocities of 5, 20, 100 and 500 mm/min, at three moisture content of 7.5%, 15% and 21% wet basis (w.b.) and at three vertical Pressure values of 14.28, 100 and 150 kPa. The following results were obtained. 1) For surface conditioning, the steel plates need to be passed through the grains for at least 7 times. 2) At low sliding velocity, by increasing the velocity from 5 to 20 mm/min, the dynamic friction coefficient of chickpea grains increased, and at a sliding velocity of 500 mm/min it was decreased. 3) For the black steel surface, by increasing the moisture content of chickpea grains from 7.5% to 15% w.b., the value of the friction coefficient increased; but at a moisture content of 21% w.b., it decreased. For galvanized steel surfaces, and sliding velocities of 5 and 20 mm/min, increasing the moisture content, the value of friction coefficient was found to decreased, but for sliding velocities of 100 and 500 mm/min its behavior was similar to the black steel surface. 4) Normal Pressure has no significant effect on the friction coefficient (at 0.01 level) and the difference between the mean values of the coefficient of friction associated with the normal Pressure of 14.28 kPa and 100 kPa, as well as 100 kPa and 150 kPa was not significant at the 0.05 significance level.