the dependence on ionic strength of protonation of l-aspartic acid and its complexation withdioxouranium(vi) is reported in sodium perchlorate solution as a background salt. the measurementshave been performed at 25 ± 0.1 °c and various ionic strengths in the range 0.1 to 1.0 mol dm-3, using acombination of potentiometric and spectrophotometric techniques. the overall analysis of the present an...

A spectrophotometric method was used to determine the acidity constant of 4'-carboxybenzo-24-crown-8 in 52% (w/w) ethanol-water mixture. The acid dissociation constant, Ka, was found to increase in the presence of Na+, K+, Rb+, Cs+ and Tl+ ions. The formation constants of the resulting 1:1 complexes between the carboxycrown a...

CONSPECTUS: All-atom methods treat solute and solvent at the same level of electronic structure theory and statistical mechanics. All-atom computation of acidity constants (pKa) and redox potentials is still a challenge. In this Account, we review such a method combining density functional theory based molecular dynamics (DFTMD) and free energy perturbation (FEP) methods. The key computational ...

A novel Mo-promoted Ce-Zr mixed oxide catalyst prepared by a homogeneous precipitation method was used for the selective catalytic reduction (SCR) of NO(x) with NH3. The optimal catalyst showed high NH3-SCR activity, SO2/H2O durability, and thermal stability under test conditions. The addition of Mo inhibited growth of the CeO2 particle size, improved the redox ability, and increased the amount...

Acidity of water from abandoned underground mines decreases over time, and the rate of decrease can help formulate remediation approaches and treatment system designs. The objective of this study was to determine an overall acidity decay rate for above-drainage underground mines in northern West Virginia from a large data set of mines that were closed 50 to 70 yr ago. Water quality data were ob...

The redox behavior cobalt chloride was studied voltammetrically in presence and absence of L- Carrageenan (LK) natural polymer using glassy carbon electrodes in 0.1 M KCl supporting electrode. Scan rates are studied for the redox behaviors for CoCl2 alone or in presence of L- Carrageenan (LK) natural polymer. Stability constants for the interaction of cobalt ions with L - Carageenan (LK) natura...

1. Introduction Mesoporous UL-ZSM-5 materials have zeolitic structure in the form of nano-particles inter-grown in the walls of the amorphous wormhole-like aluminosilicate mesoporous precursor, and were shown to exhibit an intermediate acidity between the parent mesoporous precursor and ZSM-5 zeolite [1,2]. These materials combine the advantages of both, i.e., microporous crystalline zeolites (...

Colonization by Helicobacter pylori partly depends on acid-dependent adherence by urease to gastric mucin. To further verify the relevance of urease adherence to colonization, the influence of acidity on the binding sites of H. pylori urease was investigated. When enzyme-based in vitro ligand capture assays were used, the effect of acidity on the binding site of H. pylori urease was determined ...

stability of the ;-; stacking interactions in the substituted-coronene||cyclooctatetraene complexes wasstudied using the computational quantum chemistry methods (where || denotes ;–; stackinginteraction, and substituted-coronene is coronene which substituted with four similar x groups; x =oh, sh, h, f, cn, and no). there are meaningful correlations between changes of geometricalparameters and t...