the performances of two-phase polymer-liquid pebax®/polyethylene glycol (peg) and three-phase polymer-liquid-solid pebax®/peg/mwnt thin film composite membranes for co2 and ch4 permeation were studied. the effect of temperature and mwnt/pebax® ratio on single gas (co2 and ch4) permeability was investigated. the permeation of both gases was measured at different temperatures from 303 to 323 ˚k. ...

The soil is a heterogeneous and anisotropic medium. Hydraulic conductivity, an intrinsic property of natural alluvial deposits varies both deterministically and randomly in space and has different values in various directions. In the present study, the permeability of natural deposits and its influence on the seepage flow through a natural alluvial deposit is studied. The 2D Finite Difference c...

Stress waves contain useful information about the properties of porous materials; they can be recovered through different non-destructive testing methods such as crosswell, vertical seismic profile, borehole logging as well as sonic tests. In all these methods, it is crucial to assess the effects of frequency on wave attributes including velocity and intrinsic attenuation. The dependency of per...

The routine measurement of direction-dependent reservoir rock properties like permeability often takes place along the axial direction of core samples. As permeability is a tensor property of porous materials, it should be fully described by a tensor matrix or by three main permeabilities in principal directions. Due to compaction, cementation, and other lithification processes, which take plac...

the volumetric changes in the coal matrix (coal shrinkage), permeability under various gas environment conditions as well as perographical properties were studied in the laboratory. the shrinkage and permeability of coal were examined with respect to changing gas type and confining pressures. the shrinkage tests were carried out in high-pressure bombs while the permeability study was conducted ...

the paper discusses the results of 30 years of radon indoor entry research. while some progress has been made, many discrepancies between current theories and experimental data still remain. misconceptions of radon transport mechanisms in homes are analyzed. the role of us environmental protection agency in radon indoor entry research is examined and the agency's policies are criticized. t...

in this research, the bioinsising impact of two wood decay fungi (pysisporinus vitreus and xylaria longipes) on radial air permeability and moisture diffusion coefficient of spruce wood (picea abies) was investigated. fungal cultivation was performed in an incubator at 25 °c and 85% relative humidity for 15, 30 and 45 days. results showed that the permeability, moisture diffusion and mass loss ...

estrogen replacement therapy (ert) in postmenopausal women may decrease the risk of coronary artery diseases (cad). we hypothesized that nitric oxide (no) releasing due to ert may be the essential factor by which endothelial permeability decreases. four groups of ovariectomized rabbits were under investigation for five weeks. groups 1 & 4 received high cholesterol diet and other two groups (2 &...