The solubility of hydrogen in amorphous silica at a temperature of 250 °C and pressures up to 75 kbar is studied using a quenching technique. The molar ratio H(2)/SiO(2) is found to linearly increase with pressure from X = 0.16 at P = 6 kbar to X = 0.53 at P = 75 kbar. An investigation of a sample with X = 0.47 by Raman spectroscopy demonstrated that hydrogen dissolves in silica in the form of ...

The reaction of hydrogen peroxide with a number of variants of sperm-whale myoglobin in which the distal pocket histidine residue (His64) had been mutated was studied with a combination of stopped-flow spectroscopy and freeze-quench EPR. The rate of the initial bimolecular reaction with hydrogen peroxide in all the proteins studied was found to depend on the polarity of the amino acid side chai...

an efficient one-pot oxidation/condensation tandem process has been developed for the synthesis of 2-substituted benzimidazole derivatives from benzylic alcohols and 1,2-phenylenediamine with use of urea-hydrogen peroxide/silica phosphoric acid  as a bifunctional catalyst. this method provides a rapid and efficient access to 2-substituted benzimidazoles.

bis(2-r-ind)zrcl2 (r: h or phenyl) was supported on different types of silica by in situ impregnation method and used for ethylene polymerization. in this method, the step of catalyst loading on support was eliminated and common alkyl aluminum (triisobutylaluminum, tiba) cocatalyst was used instead of expensive methyl aluminiumoxane (mao) cocatalyst in the polymerization. the effect of surface ...

Biological sulphate reduction is a new technology that can be used for the treatment of wastewater containing high amounts of sulpates and metals. The objective of this work was to investigate the feasibility and efficiency of biological sulphate reduction in a sulphidogenic jet loop biofilm reactor using hydrogen as electron donor. Polystyrene balls (qty: 265g, size > 2mm, density: 135 kg/m 3 ...

To examine colloid transport in geochemically heterogeneous porous media at a scale comparable to field experiments, we monitored the migration of silica-coated zirconia colloids in a two-dimensional layered porous media containing sand coated to three different extents by ferric oxyhydroxides. Transport of the colloids was measured over 1.65 m and 95 days. Colloid transport was modeled by an a...

a number of 6-hydroxy-2-benzylidene-3-coumaranones were synthesized from condensation of 6-hydroxy-3-coumaranone with appropriate aldehydes and were evaluated for their antioxidant activities. the antioxidant activity was assessed using two methods, including, 1,1-biphenyl-2-picrylhydrazyl (dpph) radical scavenging, and reducing power assays. some of the benzylidene coumaranones showed antioxid...

In the manuscript main factors that affect thermal mass of open and closed types heat storage devices are shown. Also, requirements for adsorption modules given. The calculation procedure has been refined, which includes determination load, adsorption, adsorbent mass, as well integral, structural, specific mass. masses heat-accumulating were evaluated. affecting their value analysed. It is show...