We studied equilibrium adsorption and uptake kinetics and identified molecular species that formed during sorption of carbon dioxide on amine-modified silica. Bicontinuous silicas (AMS-6 and MCM-48) were postsynthetically modified with (3-aminopropyl)triethoxysilane or (3-aminopropyl)methyldiethoxysilane, and amine-modified AMS-6 adsorbed more CO(2) than did amine-modified MCM-48. By in situ FT...

lead, copper, cobalt, nickel, iron and zinc ions form monocitrate complexes (negative charge) in citrate solution which is absorbed on the citrate form of anion-exchange resins (citrate as counter ion) y exchange of citrate ion with citrate complexes. these are subsequently recovered from the resin by 0.5m ammonium citrate eluent at ph 2.0. under optimized conditions, quantitative recovery was ...

Genetic manipulation of nitrogenase and key glutamate-forming enzymes can provide mutants that excrete fixed N2 as NH4+. A derepressed N2 fxation mutant (SK-24) has been isolated , which excretes up to 20.2 mumol of fixed N2 as NH4+ per mg of cell protein in 24 hr at room temperature. Biochemical analysis shows that this mutant, which requires glutamate for growth, releases fixed N2 as NH4+ int...

Using chiral quaternary ammonium hydroxide as base, cycloetherification of linear achiral diarylheptanoid 5, by way of an intramolecular SNAr reaction, provides enantiomerically enriched cyclophane 6 in good to excellent yield.

A silicone ladder-type polymer was successfully utilized for a matrix of an ion sensing membrane to fabricate an ion-sensitive field-effect transistor. An ion sensing membrane was readily fabricated by mixing a silicone ladder-type oligomer with a quaternary ammonium salt, casting onto the gate of the field-effect transistor, and polymerizing with heating. Since no acid catalysts were needed to...

in this research, the interaction of hexadecyl trimahyl ammonium bromide (htab) with enzyme ureasehas been investigated comprehensively at different experimental conditions such as ionic strength, proteinconcentration using ion selective membrane electrode of surfactants. the obtained binding isotherms frompotentiometnc studies have been analyzed by different theories such as wyman binding pote...

A new polymorph crystalline silica composition having uniform pore dimensions were synthesized by calcining a crystalline hydrated alkyl-ammonium silicate. The pore dimensions approximately were 6 angstrom for silicalite-1 and 11 angstrom for silicalite-2 units. The silicalite-1 was prepared hydrothermally at a pH of about 10 from a reaction mixture consist of water, amorphous silica and a ...

The role of AMP deaminase (EC 3.5.4.6) reaction in the stimulation of the regulatory enzymes of glycolysis was investigated using permeabilized yeast cells. 1) The addition of polyamine activated AMP deaminase in situ, resulting in the subsequent increase in ammonium production, which can stimulate the activity of 6-phosphofructokinase (EC 2.7.1.11) and pyruvate kinase (EC 2.7.1.40). 2) Zn2+ in...