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 mass transfer coe...

Leather manufacturing involves a crucial energy-intensive drying stage in the finishing process to remove its residual moisture. Determining drying characteristics of leather is vitally important so as to optimize the drying stage. This paper describes an analytical way for determination of the drying characteristics of leather. The model presented, is based on fundamental heat and mass tra...

the aim of this study was to investigate the rate of water vapor permeability (wvp) and moisture sorption of starch-montmorillonite (mmt) nanocomposite films. the nanocomposite films were prepared using the casting method andglycerol was used as a plasticizer. the effect of glycerol concentration on wvp of the films was determined at 25°c with a relative humidity of 0-99% (inside and outside of...

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 between t...

In a previous paper, pressure drop, flooding and mass-transfer characteristics of a novel pilot-scale distillation column called spinning cone column (SCC) were presented. Here, we present the result of comparison of mass-transfer efficiencies of SCC and structured packing. Comparison of SCC and structured packing mass-transfer characteristics show that the gas and liquid-side height of transfe...

Introduction Natural and artificial radionuclides are the main sources of human radiation exposure. These radionuclides, which are present in the environment, can enter the food chain. Rice is one of the most important food components in Iran. Radionuclides by transferring from soil to rice and entering the human body can affect human health. Materials and Methods Fourteen samples of different ...