Results 241 to 250 of about 196,806 (297)

Kinetic Analysis of Penicillin Degradation in Acidic Media

Journal of Pharmaceutical Sciences, 1976
Degradation of penicillin in acidic media (pH 2.7) was monitored by high-pressure liquid chromatography and UV spectroscopy. The effects of temperature, buffer concentration, and ionic strength were examined. A degradation pathway is proposed, and the apparent first-order rate constant and energy of activation were calculated for each reaction.
Adelbert M Knevel, Stanley L Hem
exaly   +3 more sources

Dissolution of Platinum in Acidic Media

ECS Meeting Abstracts, 2006
Abstract not Available.
Kenichiro Ota, Yuuki Koizumi, Shigenori Mitsushima, Nobuyuki Kamiya   +3 more
openaire   +1 more source

Anoxic dissolution of troilite in acidic media

Journal of Colloid and Interface Science, 2006
The anoxic dissolution of troilite (FeS) in acidic medium has been investigated at 50 degrees C using batch dissolution experiments. Two different progress variables were followed during solid dissolution, i.e., the amounts of dissolved iron (nFe) and formed hydrogen sulfide (n(H(2)S)). The experimental studies performed at hydrogen ion concentrations (
Chirita, P., Descostes, M.
openaire   +2 more sources

Hydrogen liberation from the hydrolytic dehydrogenation of hydrazine borane in acidic media

International Journal of Hydrogen Energy, 2018
Addressed herein, the hydrolytic dehydrogenation of hydrazine borane (NH4BH3, HB) was reported in acidic media using nitric acid (HNO3) as a catalyst at room conditions.
Esra Kuyuldar, Senem Karahan Gülbay, Fatih Sen   +2 more
exaly   +2 more sources

Epimerization of Benzylpenicilloic Acid in Alkaline Media

Journal of Pharmaceutical Sciences, 1984
5R,6R-Benzylpenicilloic acid was found to epimerize slowly in alkaline media to 5S,6R-benzylpenicilloic acid until equilibrium was established. Epimerization proceeded via the imine tautomer of penamaldic acid rather than the enamine form and was found to favor the 5S,6R-epimer at equilibrium.
I, Ghebre-Sellassie, S L, Hem, A M, Knevel   +2 more
openaire   +2 more sources

Investigations on Squaric Acid in Superacidic Media

Chemistry – A European Journal, 2018
AbstractThe syntheses of [OC(COX)3][MF6] and [(COX)4][MF6]2⋅2 HF were carried out in superacidic media XF/MF5 (M=As, Sb; X=H, D). The degree of protonation is highly dependent on the stoichiometric ratio of the Lewis acid with regard to squaric acid.
Manuel Schickinger, Denise Cibu, Florian Zischka, Karin Stierstorfer, Christoph Jessen, Andreas Kornath   +5 more
openaire   +2 more sources

Fluorogermanate(IV) equilibria in acid media

Polyhedron, 1990
Abstract The equilibria between Ge(OH) 4 , HF and H + ions in aqueous solution have been investigated, at 25°C in NaClO 4 as well as in LiClO 4 med The potentiometric data have been explained by the presence of GeF 4 , Ge(OH)F 4 − , GeF 6 2− , HGeF 6 − and a minor complex ...
Liberato Ciavatta, Mauro Iuliano, Raffaella Porto, Ermanno Vasca   +3 more
openaire   +2 more sources

Improved Activity in Acidic Media of Immobilized Lysozyme

Applied Biochemistry and Biotechnology, 1999
Polyethylene glycols (PEGs) of various chain length were used to crosslink lysozyme onto an insoluble support such as oxirane. A very high degree of modification and no inactivation of lysozyme were obtained with PEG 20000, but enzymatic activity increased up to 20 times at pH 3.0, at which point the activity of the native enzyme was lower when using ...
ZACCHIGNA, MARINA, DI LUCA GABRIELLA, LASSIANI, LUCIA, VARNAVAS ANTONIOS, PITOTTI ANNA, BOCCÙ ENRICO   +5 more
openaire   +3 more sources

Reactions of ketones with aromatics in acid media. The effect of trifluoromethyl groups and the acidity media. A theoretical study

Journal of Molecular Modeling, 2012
The reactions of acetone, 2,2,2-trifluoroacetone and hexafluoroacetone in methanesulfonic (MSA) and triflic acids (TFSA) with benzene have been studied at M06-2X/6-311+G(d,p) level using cluster-continuum model, where the carbonyl group is explicitly solvated by acid molecules.
Ulises Jiménez, Castillo, Mikhail G, Zolotukhin, Lioudmila, Fomina, Daniel Romero, Nieto, Lilian Olivera, Garza, Serguei, Fomine   +5 more
openaire   +2 more sources