Selective oxidation of carboxylate groups present in alginic acid by Cr(VI) affords CO2, oxidized alginic acid, and Cr(III) as final products. The redox reaction afforded first-order kinetics in [alginic acid], [Cr(VI)], and [H(+)], at fixed ionic strength and temperature. Kinetic studies showed that the redox reaction proceeds through a mechanism which combines Cr(VI)→Cr(IV)→Cr(II) and Cr(VI)→...

In a recent paper, Descostes et al. (2004) present data on a series of pyrite oxidation batch experiments conducted near pH 2 and 3 where they demonstrate very well the non-stoichiometric dissolution/oxidation of pyrite in acidic solutions through an extensive laboratory investigation of S/Fe ratios. The authors utilized this data to propose a ‘mechanism’ of pyrite oxidation based on these data...

Additional bimetallic electrocatalysts for the oxygen reduction reaction ORR in acidic media were designed using a previously reported thermodynamic selection guide. The electrocatalyst mixtures were prepared in large arrays on glassy carbon substrates and the electrocatalytic activity was screened using scanning electrochemical microscopy SECM . Activities were measured for a range of bimetall...

An account is given of some recent developments in the chemistry of solutions in highly associated strong protonic acid solvents, including sulphuric acid and oleums, fluorosuiphuric acid and hydrogen fluoride. Topics discussed include solvent—solute interactions, super-acid systems, Hammett acidity functions and polyatomic cations of the elements of Groups VI and VII.

background: based on recent studies, there are controversial reports on the ca-pacity of tissue cyst forming of toxoplasma gondii rh strain. in this study, the capac-ity was evaluated by in vivo and in vitro experiments. methods : rh strain was subcutaneously inoculated to ten wistar rats. after one month, their blood, brain, tongue and diaphragm were collected and evaluated by mat, pcr, pathol...

Air-stable Lewis acidic micro2-hydroxy bridged binuclear complex of zirconocene pentafluorophenylsulfonate was successfully synthesized and found to show high catalytic efficiency in chemoselective allylation of carbonyl compounds with tetraallyltin in aqueous methanol media.

Three Staphylococcus epidermidis strains produced a factor giving rise to opacity in different sera but not in albumin. Serum opacity factor was resistant to age and heat and active in acidic media.

[reaction: see text] Nanometer tin-mediated allylation of aldehydes or ketones in distilled or tap water gave rise to corresponding homoallyl alcohol in high yield without any other assistance such as heat or supersonic or acidic media.

Extreme pHs, especially acidic pHs, are among the environmental stresses that some bacteria face. The most important strategies that bacteria employ for acid adaptation include either production of acidophilic proteins, or raising the pH of the microenvironment by secretion of basic compounds including ammonia produced by the action of urease. Considering the importance of acid-neutralizing bac...

Graphene quantum dots prepared by a one-step hydrothermal procedure in a microwave exhibit an unusual emission transformation in strong acidic media and at high concentration, induced by self-assembled J-type aggregation under restrained π-π interactions.