A mass transfer model is proposed for prediction of permeate concentration and percent rejection at different inlet pressures and feed dye concentrations in membrane ultrafiltration. A differential equation in cylindrical co-ordinates considering the spiral wound membrane equivalent to a cylindrical module is derived which coupled with mass balance and permeate flux equations are solved to yiel...

The Canadian Journal of Chemical Engineering, Volume 81, February 2003 Complex flows with boundary layer separation and reattachment commonly occur in situations of practical interest. In such flows, any accompanying heat or mass transfer is strongly influenced by the fluid dynamics. For example, rates of heat or mass transfer to the wall can have large variations in the reattachment region. In...

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 coeffici...

A study on heat and mass transfer behaviour on an anisotropic porous medium embedded in square cavity/annulus is conducted using Incompressibe Smoothed Particle Hydrodynamics (ISPH) method. In the case of square cavity, the left wall has hot temperature Th and mass Ch and the right wall has cool temperature Tc and mass Cc and both of the top and bottom walls are adiabatic. While in the case of ...

background: successful embryo transfer (et) technique is a fateful step of all efforts to achieve live births from in vitro produced embryos in assisted reproductive techniques or in knockout, transgenic or cloned animal projects. small reproductive tract of mice and limitation of current techniques may not well satisfy the requirements for mass production of genetically modified mice. genetic ...

A computer model for a hot gas-fluidized bed has been developed. The theoretical description is based on a two-fluid model ( TFM) approach in which both phases are considered to be continuous and fully interpenetrating. Local wall-to-bed heattransfer coefficients have been calculated by the simultaneous solution of the TFM conservation of mass, momentum and thermal energy equations. Preliminary...

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...

the effects and influences of various parameters upon the efficiency and the overall volumetric mass transfer coefficients are important subjects to be studied in most liquid-liquid extraction processes. one of these important parameters is surface active agent (surfactant). in this paper, in order to study the effect of sodium dodecyl sulfate (sds) concentration on the efficiency and the avera...

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...