Pollutants in the form of non-aqueous phase liquids (NAPLs), such as petroleum products, pose a serious threat to the soil and groundwater. A mathematical model was derived to study the unsteady pollutant concentrations through water saturated contaminated soil under air sparging conditions for different NAPLs and soil properties. The comparison between the numerical model results and the publi...

The mass transfer performance of a pulsed disc and doughnut column for extraction of samarium and gadolinium from aqueous nitrate solution with D2EHPA was investigated. The effects of operating parameters such as pulsation intensity, continuous and dispersed phase velocities on column performance were investigated. The axial dispersion model was used to obtain the overall mass transfer coef...

An experimental investigation was conducted to study the average and the fully-developed heat (mass) transfer coefficients in a rectangular smooth duct and a duct with repeated-baffle blockages. The focus of attention in this work is the conventional correlation Nu / Nufd 1 + C / ( X / D ) for the average heat transfer coefficient. It was shown that for relatively short ducts, the coefficient C...

frying is an important unit operation used widely both in domestic and industrial cooking. reduced pressure (vacuum), microwave, deep fat and pan frying are the most important methods of food frying. final product has good organoleptic quality (colour, texture, and flavour). the accuracy of the knowledge of mass transfer parameters (effective diffusivity coefficient, dimensionless biot number a...

in order to simulate the rotating disk contactor all hydrodynamic parameters, dispersed phase hold-up, characteristic velocity, mean drop size, drop size distribution, axial mixing and mass transfer have been taken into account. mechanisms of mass transfer (stagnant, circulating, oscillating drops) were used in this study. column height found from effect of mean drop size and drop size distribu...

An analytical study was performed to study effects of thermo-diffusion and chemical reactions on a three-dimensional MHD mixed convective flow of dissipative fluid along an infinite vertical porous plate with transverse sinusoidal suction velocity. The parabolic partial differential equations governing the fluid flow, heat transfer, and mass transfer were solved using perturbation technique and...

In this study, the diffusivity and volumetric mass transfer coefficients for the extraction of β-carotene from crude palm oil using CO2 solvent in supercritical fluid were determined in the pressure range of 7.5-17.5 MPa and temperature range of 80-120 ºC. For this purpose, a statistical method was applied in order to minimize the number of experiments required. The volumetric ma...

This paper presents a numerical study of local mass transfer coefficients in a 90° bend using the RNG version of k–e model to include the influence of curvature on the turbulent transport. Simulations were performed for flow through a 90°, 3-D bend for Reynolds numbers of 13500, 90000, and 390000, Schmidt numbers of 2.53 and 700 and curvature ratios of 1.5, 2, and 2.5. The differences betwe...