Membrane fouling during particle filtration occurs through a variety of mechanisms, including internal pore clogging by contaminants, coverage of pore entrances and deposition on the membrane surface. In this paper, we present an efficient method for modelling the behaviour of a filter, which accounts for different retention mechanisms, particle sizes and membrane geometries. The membrane is as...

We have studied adsorption in regular, self-ordered alumina pores open at both ends or only at one end. The straight, non-connected pores have diameters ranging from 22 to 83 nm, with a relative dispersion below 1% in the pore size. Adsorption isotherms measured in open pores with a torsional microbalance show pronounced hysteresis loops characterized by nearly vertical and parallel adsorption ...

Tetrodotoxin-resistant (TTX-R) Na(+) channels are much less susceptible to external TTX but more susceptible to external Cd(2+) block than tetrodotoxin-sensitive (TTX-S) Na(+) channels. Both TTX and Cd(2+) seem to block the channel near the "DEKA" ring, which is probably part of a multi-ion single-file region adjacent to the external pore mouth and is involved in the selectivity filter of the c...

A physical model of selective "ion binding" in the L-type calcium channel is constructed, and consequences of the model are compared with experimental data. This reduced model treats only ions and the carboxylate oxygens of the EEEE locus explicitly and restricts interactions to hard-core repulsion and ion-ion and ion-dielectric electrostatic forces. The structural atoms provide a flexible envi...

Aldol condensation of n -pentanal can lead to pore blocking and hence transport limitations in supported liquid phase (SLP) catalysts. By careful texture optimization this effect be minimized.

Voltage-gated ion channels generate electrical signals in species from bacteria to man. Their voltage-sensing modules are responsible for initiation of action potentials and graded membrane potential changes in response to synaptic input and other physiological stimuli. Extensive structure-function studies, structure determination, and molecular modeling are now converging on a sliding-helix me...

because most contaminants in water create strong interactions with hydrophobic surfaces, there are usually problems such as flux decline and pore blocking in polyethylene (pe) membranes due to irreversible adsorption of foulants on their intrinsic hydrophobic surface. therefore, in this work, attempts were made to improve the properties of pe membranes in terms of water flux and membrane foulin...

Multilayer diffusion and capillary condensation of propylene on supported y-alumina films greatly improved the permeability and selectivity. Multilayer diffusion, occurring at relative pressures of 0.4 to 0.8 strongly increased the permeability to 6 times the Knudsen permeability, yielding permeabilities of 3.2 x 10m5 mol/m’-see-Pa. The occurrence of a maximum in the permeability coincides with...

The activity of single L-type Ca2+ channels was recorded from cell-attached patches on acutely isolated skeletal muscle fibers from the mouse. The experiments were concerned with the mechanism by which aminoglycoside antibiotics inhibit ion flow through the channel. Aminoglycosides produced discrete fluctuations in the single-channel current when added to the external solution. The blocking kin...

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...