Various methods have been used by different investigators t.o estimate the stability of amide to amide hydrogen bonds in aqueous solution. Schellman (1) and Kauzmann (2) have discussed the thermodynamic properties of t)he C=O--HN bond in water wit,h the use of aqueous urea solutions as a model system. From studies on heats of dilution of urea in water, Schellman concluded that this bond has an ...

1. In the growth and death of the pneumococcus in fluid media containing 1 per cent glucose the production of acid is the most important bactericidal factor. 2. 1 per cent glucose bouillon cultures of the pneumococcus allowed to grow and die out usually reach a final acidity of a pH of about 5.1. 3. At a hydrogen ion concentration of about 5.1 or higher, the pneumococcus does not survive longer...

In this paper we present amorphous chromium(III) hydride gels that show promise as reversible room temperature hydrogen storage materials with potential for exploitation in mobile applications. The material uses hydride ligands as a light weight structural feature to link chromium(III) metal centres together which act as binding sites for further dihydrogen molecules via the Kubas interaction, ...

Fracture surface of Zircaloy-2 specimens tested under constant crosshead speed in CH3OH/0.4 Vol. %HCI solution with and without selenium (25 ppm) addition was studied. Using a combined process of deformation and annealing, coarse grained material was also obtained and examined. Two modes of stress corrosion crack propagation were observed: an intergranular zone caused by stress assisted anodic ...

leaching of molybdenite concentrate with hydrogen peroxide in sulfuric acid solution was investigated to determine the effects of reaction time, reaction temperature, h2o2 concentration, h2so4 concentration, pulp density and rotation speed on molybdenum extraction and molybdenite dissolution kinetics, using the taguchi method. from analysis of variance (anova) for molybdenum extraction, the mos...

This work studied artemether (ARTM) solid dispersion (SD) formulation using mixture of polymer excipient Soluplus, PEG 400, Lutrol F127, and Lutrol F68 melts at temperatures lower than the melting point of ARTM using a laboratory-size, single-screw rotating batch extruder. The effects of three surfactants PEG 400, Lutrol F127, and Lutrol F68 and parameters like mixing temperature, screw rotatin...

poorly water-soluble drugs often suffer from limited or irreproducible clinical response due to their low solubility and dissolution rate. in this study, organic solvent-free solid dispersions (osf-sds) containing telmisartan (tel) were prepared using polyvinylpyrrolidone k30 (pvp k30) and polyethylene glycol 6000 (peg 6000) as hydrophilic polymers, sodium hydroxide (naoh) as an alkalizer, and ...