• Salt permeability of polyamide RO membranes is invariant in a wide salinity range. The solution diffusion model adequately describes our seawater membranes. Membrane leaks may cause correlation between and observed salt permeability. New developments modeling solute transport reverse osmosis (RO) are based on the mechanistic description friction electromigration. In these models, membrane cha...

The effects of various inhibitors on the membrane potential, resistance, and K(+) permeability of Chara corallina were measured, providing evidence that there is an electrogenic pump in the membrane. It was found that: (a) 5.0 mum carbonyl cyanide m-chlorophenyl hydrazone depolarizes the membrane potential and increases the membrane resistance. This inhibition is faster in the dark than in the ...

The impact of humic acid fouling on the membrane transport of two pharmaceutically active compounds (PhACs) - namely carbamazepine and sulfamethoxazole - in forward osmosis (FO) was investigated. Deposition of humic acid onto the membrane surface was promoted by the complexation with calcium ions in the feed solution and the increase in ionic strength at the membrane surface due to the reverse ...

Aerobic operation of an immersed hollow fibre membrane bioreactor, treating municipal wastewater supplemented with molasses solution, has been studied across mixed liquor suspended solids (MLSS) concentrations between 8 and 32 g L(-1), the higher concentrations being normally associated with thickening operations. Only a marginal loss in membrane permeability was noted between 8 and 18 g L(-1) ...

The permeability of the squid axon membrane was determined by the use of radioisotopes of Na, K, Ca, Cs, and Br. Effluxes of these isotopes were measured mainly by the method of intracellular injection. Measurements of influxes were carried out under continuous intracellular perfusion with an isotonic solution of potassium sulfate. The Na permeability of the resting (excitable) axonal membrane ...

One of the main fundamental mechanisms of antibiotic resistance in Gram-negative bacteria comprises an effective change in the membrane permeability to antibiotics. The Gram-negative bacterial complex cell envelope comprises an outer membrane that delimits the periplasm from the exterior environment. The outer membrane contains numerous protein channels, termed as porins or nanopores, which are...

The purpose of this work was to investigate the synthetic phospholipid dependence of permeability measured by parallel artificial membrane permeability assay (PAMPA) method. Three phospholipids with hydrophobic groups of different lengths and phosphorylcholine as the hydrophilic group were concisely synthesized. Ten model drug molecules were selected because of their distinct human fraction abs...

The effect of environmental temperature on plasma membrane permeability to Adriamycin was studied in Chinese hamster ovary (CHO) cells in vitro using flow cytometry. Initial rates of uptake increased steadily between 23 degrees C and 47 degrees C and there was a greater than 2-fold increase in permeability between 37 degrees C and 47 degrees C. The increase in permeability with increasing tempe...

This paper presents the results of 195 days of pilot-scale submerged membrane bioreactor (SMBR) experiments on settled municipal wastewater. Short-term and long-term thickening experiments were performed at a constant membrane flux of 30L/(m(2)h) to determine the impact of the following mixed liquor properties: colloidal material, soluble COD, soluble microbial products, extracellular polymeric...

The relationships of potato (Solanum tuberosum L.) tuber membrane permeability and membrane lipid composition to sugar accumulation were examined. Tubers from four potato cultivars were stored for 40 weeks at 3 degrees C and 9 degrees C. Rates of tuber membrane electrolyte leakage, total fatty acid composition, free fatty acid composition, and sugar content were measured throughout the storage ...