the molecular sieves are selective adsorbents. they can adsorb some kind of molecules that are different in size or shape from the others. in separation of n-paraffins from iso-paraffins and aromatics, sa molecular sieve is the suitable adsorbent, and can adsorb n-paraffins to separate them from other hydrocarbons. in this paper equilibrium isotherms of n-cs, n-c6 and n-c7 from an inert solvent...

in this work, bsea-sba-15 was prepared for the first time, which was prepared by covalently anchoring schiff-base compound (n,n´-bis(salicylidene)ethylenediamine (bsea) on sba-15 by hydrothermal method. the structure and physicochemical properties were determined by elemental analysis, xrd, nitrogen adsorption–desorption, thermogravimetric analysis and ftir spectroscopy, sem, bet surface area a...

The quasi-static theory of poroelasticity presented by Biot and Gassmann provides a relationship between the drained and undrained elastic constants of an isotropic fluid-saturated porous material in terms of the porosity of the material, bulk modulus of the solid grains, and bulk modulus of the pore fluid. We have developed an alternative approach to derive the Biot-Gassmann (BG) relationship ...

We study the nucleation of a single pore in a fluctuating lipid membrane, specifically taking into account the membrane fluctuations, as well as the shape fluctuations of the pore. For large enough pores, the nucleation free energy is well-described by shifts in the effective membrane surface tension and the pore line tension. Using our framework, we derive the stability criteria for the variou...

excess pore pressure under seismic loadings has always been a main concern in geotechnical engineering practices. the phenomenon in soil can cause an effective stress and hence cause the shear strength of the soil to decrease considerably and large deformations to occur in the area. generally, increases in pore pressure occur in un-drained conditions. if it is formed, its consequences decrease ...

in this work, a simple and effective way to modify the support surface is developed and a nanostructure ceramic support to facilitate deposition of a defect-free overlying micro and meso (nano) porous membrane is obtained. to achieve high performance nanocomposite membranes, average pore size of outer surface of support was reduced by dip-coating in submicron and nano α-alumina slurries. in thi...

This investigation indicates the ability to selectively graft glycidyl methacrylate (GMA) only from the external surface of regenerated cellulose (RC) ultrafiltration (UF) membranes using activator generated electron transfer (AGET) atom transfer radical polymerization (ATRP). This controlled polymerization resulted in epoxy functionalized polymer brush ends. Further reaction of the terminal ep...

Investigation of pore system properties of carbonate reservoirs has an important role in evaluating the reservoir quality and delineating high production intervals. The current study proposes a three-step approach for pore throat size characterization of these reservoirs, by integrating core data, well logs and 3D seismic volume. In this respect, first the pore throats size was calculated using...

[1] We report on laboratory experiments designed to investigate the influence of pore pressure oscillations on the effective permeability of fractured rock. Berea sandstone samples were fractured in situ under triaxial stresses of tens of megapascals, and deionized water was forced through the incipient fracture under conditions of steady and oscillating pore pressure. We find that short‐term p...