a proton nmr method for the drtermination of salvation numbers of alkaline earth cations with hexamethyl phosphoramide (hmpa) in nitromethane (nm) as diluents is described. the method is based on monitoring the resonance frequency of hmpa protons as a function of hmpa / metal ion molar ratio at constant metalion concentration. the average salvation number of cations,  , at any hmpa / metal ion ...

in this study, the adsorption of thallium (iii) ion from aqueous solutions onto modified znonanopowder as a fairly low cost adsorbent has been investigated in batch mode. it was found thatmodification of the adsorbent was essential for obtaining the significant adsorption percentage. theadsorbent modified by sodium phosphate solution. the effect of experimental parameters such asinitial ph of s...

The effect of hydrogen-ion concentration on the toxicity of various organic and inorganic compounds has been studied by a number of investigators. In general the results have shown that the toxicity of anions is increased by increasing the hydrogen-ion concentration and that of cations is increased by decreasing the hydrogen-ion concentration, provided the reaction does not affect the solubilit...

We studied effects of free copper ion activity and total copper concentration on copper uptake by lettuce from nutrient solution and a model was developed. In ethylenediaminetetraacetic acid and dissolved organic matter treatments, when pH and free copper ion activity were the same, root copper concentration did not change with the total copper concentration. However, at fixed pH and total copp...

in this study, polystyrene ethylene butylene polystyrene (psebs) was functionalized to prepare mono and bipolar ion exchange membranes. in the case of the bipolar membrane, platinum was used as the intermediate layer. nacl solution of concentration ranging from 5 g/l to 25 g/l was used as the feed solution. a commercially procured ion exchange membrane made of polystyrene divinyl benzene was al...

Cells from animals, plants and single cells are enclosed by a barrier called the cell membrane that separates the cytoplasm from the outside. Cell layers such as epithelia also form a barrier that separates the inside from the outside or different compartments of multicellular organisms. A key feature of these barriers is the differential distribution of ions across cell membranes or cell layer...

Metal ions play crucial roles in thermal stability and folding kinetics of nucleic acids. For ions (especially multivalent ions) in the close vicinity of nucleic acid surface, interion correlations and ion-binding mode fluctuations may be important. Poisson-Boltzmann theory ignores these effects whereas the recently developed tightly bound ion (TBI) theory explicitly accounts for these effects....