two dimensional thin layer chromatography on polyamide sheets is a useful method for identification of pth-amino acids which have very close rf-values. the solvent systems described here are particularly effective and have an edge over other solvent systems used for the separation of pth-amino acids. the solvent systems provide a clear separation of all pth-amono acids except lle / leu in a rel...

formation of asphaltene deposition during oil production, processing and synthesis is known as a fundamental problem of petroleum reservoir worldwide. asphaltene is a petroleum fraction that can lead to increasing the operating costs in these industries. variations in operational pressure, temperature and fluid composition are generally the significant cause of asphaltene precipitation. in this...

The potent dehydrating ability of difluoro(aryl)-lambda (3)-iodanes is exploited to develop a convenient (19)F-NMR-based aquametry method that is more sensitive than coulometric Karl Fischer titration. The key difluoro(aryl)-lambda (3)-iodane reagents are synthesized readily from commercially available and inexpensive precursors.

mesoporous photocatalysts of ceo2/sba-15 are prepared by two methods of direct synthesis as solvent-usage and solvent-free methods. in solvent-usage method, ceo2/sba-15 is synthesized in acidic media. while, in solvent-free method, ceo2/sba-15, has been prepared through the novel path of directly grind cerium salt into the as-prepared samples of sba-15 occluded with template. this method enable...

Solvent accessibility is an important structural feature for a protein. We propose a new method for solvent accessibility prediction that uses known structure and sequence information more efficiently. We first estimate the relative solvent accessibility of the query protein using fuzzy mean operator from the solvent accessibilities of known structure fragments that have similar sequences to th...

the aim of this study was to formulate and evaluate microencapsulated controlled release preparations of a highly water/soluble drug, salbutamol sulphate by (water in oil) in oil emulsion technique using ethyl cellulose as the retardant material. various processing and formulation parameters such as drug/polymer ratio, stirring speed, volume of processing medium were optimized to maximize the e...