The potential use of nanoclay was examined to modify fluid transfer properties of medium density fiberboard (MDF). For this, Na+ montmorillonite (Na+MMT) nanoclay was added to urea formaldehyde resin to produce MDF. Then, the air permeability and mass diffusivity of MDF were evaluated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) confirmed a dispersion and exfoliation o...

Epinephrine increases the permeability of isolated frog sartorius muscles to 3-O-methyl-~-glucose. This effect resembles the action of insulin in that, at 19’, there is an absolute lag of 30 min preceding a rise in permeability, while at 0” no alteration of permeability is seen during several hours of incubation. The delayed effect of epinephrine on permeability contrasts with its prompt glycog...

The water-gas relative permeability is an important parameter to characterize multiphase flow in sediments. To study the of hydrate-bearing porous media, simulations were carried out at pore scale using lattice Boltzmann method. effects hydrate saturation and hydrate-growth habits on permeability, which scaled by considering only, evaluated a two-dimensional medium. Results show that increase c...

In the present paper, the theoretical investigation of the double-diffusive convection in a micropolar fluid layer heated and soluted from below saturating a porous medium is considered. For a flat fluid layer contained between two free boundaries, an exact solution is obtained. A linear stability analysis theory and normal mode analysis method have been used. For the case of stationary convect...

Endothelial properties are affected by mechanical stresses. Several studies have shown that an acute application of shear stress increases the permeability of endothelial monolayers in culture. We investigated whether more prolonged application of shear has the opposite effect. Porcine aortic endothelial cells were cultured on Transwell filters to assess monolayer permeability to albumin. The m...

A model function relating effective stress to fracture permeability is developed from Hooke's law, implemented in the tensorial form of Darcy's law, and used to evaluate discharge rates and pressure distributions at regional scales. The model takes into account elastic and statistical fracture parameters, and is able to simulate real stress-dependent permeabilities from laboratory to field stud...

This paper investigates the permeability of several multi-layered, woven filter media using air, water and bubble point methods. Estimated filter efficiencies from the bubble point measurements were then compared to a new sonic challenge test method where precision microspheres are fluidised through the pores. Inconsistencies in the bubble point filter efficiencies were found to be dependent on...

1. The isotopic water permeability coefficient, P, of the plasma membrane of frog body cavity eggs has been determined as a function of the incubation time in media of different tonicity. 2. It was found that the permeability decreases with the incubation time in hypotonic solutions. The observed changes may be correlated with an increase of the tension in the vitelline membrane. 3. In the eval...

Purpose: To measure the extent of solubility of the lipophilic drug, aceclofenac, in 13 oils as well as its in vitro permeability from these oils in order to develop optimized topical microemulsion and microemulsion-based gel for improved bioavailability. Methods: UV spectrophotometeric method was used at the wavelength of 276 nm to measure the dissolved quantity of aceclofenac in each of the o...

We used a perfused gill preparation from dogfish to investigate the origin of low branchial permeability to urea. Urea permeability (14C-urea) was measured simultaneously with diffusional water permeability (3H2O). Permeability coefficients for urea and ammonia in the perfused preparation were almost identical to in vivo values. The permeability coefficient of urea was 0.032 x 10(-6) cm/sec and...