nowadays, hydrogels are widely used as wound dressings in biomedical applications. similar to other types of the moist (wet) wound dressings, it is necessary to have sufficient information about their dehydration kinetics during the pre-usage period (e.g. storage duration) and also the wound healing process. in this work, hydrogel wound dressings based on polyvinyl alcohol were prepared by cycl...

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 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...

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...

Mass Transfer ................................................................................................................................................ 1 What it is and what it isn't ......................................................................................................................... 1 What it is for. Applications .........................................................

Mass Transfer ................................................................................................................................................ 1 What it is and what it isn't ......................................................................................................................... 1 What it is for. Applications .........................................................

Mass Transfer ................................................................................................................................................ 1 What it is and what it isn't ......................................................................................................................... 1 What it is for. Applications .........................................................

An analytical investigation is conducted to study the unsteady free convection heat and mass transfer flow through a non-homogeneous porous medium with variable permeability bounded by an infinite porous vertical plate in slip flow regime while taking into account the thermal radiation, chemical reaction, the Soret number, and temperature gradient dependent heat source. The flow is considered u...

output characteristics of fuel cells are affected by a large number of parameters such as geometry, dimensions, construction materials and conditions of supplying fluids. in this paper a mathematical model followed by a two-dimensional numerical approach has been presented to study the fuel cell parametrically. effect of oxygen concentration at gas diffusion layer entrance, temperature and pres...

Heat transfer coefficient in nucleate pool boiling near critical heat flux at least one orderhigher than the convectional heat transfer modes. In this paper, an experimental setup isdesigned and fabricated to investigate the mechanism of heat transfer from boiling surface tobulk liquid near critical heat flux. The images of pool boiling near the high heat flux regionreveals that the individual ...