New chiral catalyst systems were developed for the reaction of carbon dioxide with propylene oxide (PO) at atmospheric pressure to generate enantiomerically enriched propylene carbonate (PC). The best selectivity was achieved with a Co(III)(salen)-trifluoroacetyl complex and bis(triphenylphosphoranylidene)ammonium fluoride (PPN+F-) as catalysts, affording PC in 40% yield and 83% ee (selectivity...

The transport of carbonate ions through a supported liquid membrane in the presence and absence of carriers has been explored. The liquid membrane used was the combined liquid cation and anion exchangers in toluene immobilized in the porous polypropylene support. The permeability coefficient (P) of carbonate ions transport from the source to receiving through membrane phase has been estimated. ...

Of 50 patients with urinary calculi, upper tract stones were common between 15-44 and lower tract stones between 0-14 and above 44 years of age. Urinary calculi contained calcium, phosphate, oxalate, urate/uric acid, ammonium, magnesium and carbonate. The frequency of occurrence of each of these radicals in sixty stones was 93.33, 83.33, 61.67, 51.67, 25.00 and 13.33% respectively. Five (27.78%...

Biomineralization is a known natural phenomenon associated with a wide range of bacterial species. Bacterial-induced calcium carbonate precipitation by marine isolates was investigated in this study. Three genera of ureolytic bacteria, Sporosarcina sp., Bacillus sp. and Brevundimonas sp. were observed to precipitate calcium carbonate minerals. Of these species, Sporosarcina sp. dominated the cu...

ammonium carbonate and ammonium sulfate have been proposed and used as two new fuels for synthesizing gamma alumina nanoparticles. the prepared samples have been characterized by x-ray diffraction (xrd), 2 n  adsorption (bet) and transmission electron microscopy (tem). a comparison has been made between the properties of the nanoparticles synthesized by these two fuels and other conventional fu...

A streptomyces antibiotic, bellenamine has been produced in a simple synthetic medium consisting of D-galactose, dextrin, ammonium sulfate and calcium carbonate. Three new minor metabolites, N-(aminomethyl)succinamic acid, 1'-N-acetylbellenamine and D-beta-lysinamide have been isolated from the synthetic medium culture. They showed no antibiotic activity.

A brick-and-mortar-like ultrasoft nanocomposite metallogel is formed by crosslinking cellulose nanocrystals (CNC) with ammonium zirconium carbonate (AZC) to trap and reconfigure dextran, a model biomacromolecule. The bricks (CNC) reinforce the metallogel, compete with dextran in reacting with AZC, and decouple long-time dextran dynamics from network formation, while the mortar (AZC) imparts bim...

Ammonium carbonate and ammonium sulfate have been proposed and used as two new fuels for synthesizing gamma alumina nanoparticles. The prepared samples have been characterized by X-ray diffraction (XRD), 2 N  adsorption (BET) and Transmission electron microscopy (TEM). A comparison has been made between the properties of the nanoparticles synthesized by these two fuels and other conventio...