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...

The formation of low-mass X-ray binaries containing a rather massive (M >∼ 7M ) black hole is problematic because in most recent stellar evolutionary calculations the immediate progenitors of these black holes (Wolf-Rayet stars) lose so much mass via their stellar wind that their final masses are well below the observed black hole masses. We discuss the recently proposed solution that these bin...

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...

Trapezoidal grooves were arranged in channel sidewalls of the proposed micro-channel heat sinks to enhance transfer for cooling microelectronic systems. The 3-D numerical simulations carried out investigate characteristics fluid-flow and micro-channels. Field structures thermal fluid-flow, Nusselt number, friction factor, f, employed study effects relative groove depth, ?, spacing length, trape...

Depending on the outcome of pre-CV formation, mass transfer may set in under thermally unstable conditions in a significant number of systems. Full computations have shown that such an early phase of thermal-timescale mass transfer usually leads to ordinary looking CVs, but these do also show some unusual properties (e.g. chemical anomalies in later stages). Rather than investigating the common...

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...

Voltage-dependent ion channels open and conduct ions in response to changes in cell-membrane voltage. The voltage sensitivity of these channels arises from the motion of charged arginine residues located on the S4 helices of the channel's voltage sensors. In KvAP, a prokaryotic voltage-dependent K+ channel, the S4 helix forms part of a helical hairpin structure, the voltage-sensor paddle. We ha...

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 .........................................................

The influence of variation in rib-height to channel-height ratio (e/H) on the heat transfer and pressure drop characteristics inside a channel with corrugated upper and lower plates was investigated numerically in the present study. The governing equations were solved by using finite volume approximations for a wide range of (0.06 < e/H < 0.26) and Reynolds numbers (5400 < Re < 23000), with a m...