This work examines the volumetric effect of convection within a packed bed in the presence of collimated irradiation. Using a modified P-1 approximation incorporating a local thermal nonequilibrium (LTNE) model, the energy transportation through convection and thermal conduction, and collimated and diffuse radiative transfer are investigated. The impact of pertinent parameters such as porosity ...

in the presented research, heat transfer of a mobile electrolyte alkaline fuel cell (afc) (which the electrolyte has cooling role of system) has been considered. proper control volumes of system with specific qualification have been chosen. consequently, heat and mass transfer in control volumes have been assessed. considerations on them and contributed models lead to approve a double tube heat...

This study examined the mass transfer performance in a pulsed perforated-plate extraction column with diameter of 50 mm using two different liquid systems. Mass transfer coefficients have been interpreted in terms of the axial diffusion model. The effects of pulsation intensity and dispersed and continuous phase velocities on the mass transfer performance have been investigated. Three different...

The kinetic of the heterogeneous chemical reaction of aluminum hydroxide and fluosilicic acid was studied. It was found that the diffusion of the reactants through the porous silica coating to the aluminum hydroxide surface and the interfacial chemical reaction between the diffusing reactant and aluminum hydroxide platelets control the overall reaction rate. These two phenomena were studied...

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...

A consecutive-reaction kinetic model for the sucrose-fed upflow anaerobic sludge bed (UASB) reactor that accounts for a layered structure of the granule and the mass fraction of methanogens (f) is proposed. When the UASB reactor was maintained at the volumetric loading rates (VLR) of 7.9-13.8 kg chemical oxygen demand (COD)/m(3) d, the accumulated volatile fatty acids (VFAs) increased with incr...

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...

Transfer functions play a critical role in feature detection through direct volume rendering in volumetric scalar fields. Because of the inherent difficulties of exploratory visualization, assisting the user in transfer function specification is still an important area of research. In particular, the disparate nature of simulated and measured volumetric data necessitates more flexibility in the...

The oxygen carrying performance of a perfluorooctyl bromide (PFOB) emulsion is considered. The intended purpose is to enhance hepatocyte growth and function in a bio-artificial liver support system (BALSS). Such oxygen carrying emulsions have previously been used in biological systems (e.g. cell culturing). However, optimum emulsion characteristics for enhanced oxygen mass transfer have not bee...

The main objective of this paper is to examine the effect of nanomaterials on mass transfer coefficient in bubble type absorption of carbon dioxide by experiment. The absorption process is carried out in a bubble column and in room temperature. Mass transfer coefficient, saturated concentration of CO2, and gas holdup are determined in this system. The kinds of nanomaterials, the concentrations ...