Electrogeneration of Hg(+) in the presence of tryptophan

In the presence of l-tryptophan, a one-electron oxidation of mercury takes place at the dropping mercury electrode at 0.265 V vs. SCE in 0.1M potassium nitrate. The electrogeneration of the monomeric Hg(+) ion has been established by a.c. polarography, cyclic voltammetry and ultraviolet spectroscopy. A paramagnetic Hg-trp compound has been electrochemically synthesized and characterized.     

Wave propagation in a micropolar fluid contained in a visco-elastic membrane

The aim of the paper is to investigate the propagation of a pulse in a micropolar fluid contained in a visco-elastic membrane. It was undertaken with a view to study how closely we can approximate the flow of blood in arteries by the above model. We find that for large Reynolds number, the effect of micropolarity is hardly perceptible, whereas for small Reynolds numbers it is of considerable importance.     

Chemoprofiling and Solamargine Estimation from a Few Solanum Species Used as ‘Brihati’ and Its Market Samples Using a Validated High-Performance Thin-Layer Chromatography Method

JPC – Journal of Planar Chromatography – Modern TLC - An ingredient of ‘Dasamoola’ and ‘Laghupanchamoola’ group of drugs, the source of ‘Brihati’ has...     

Stabilization of merocyanine by protonation, charge, and external electric fields and effects on the isomerization of spiropyran: a computational study

Protonation, charging, and field effects on the thermal isomerization of a nitrospiropyran (SP) modified by a thiolated etheroxide chain into merocyanine (MC) are computationally studied at the DFT level. The ring opening leads to cis-MC conformers that then isomerize to the more stable trans forms. While the closed neutral spiropyran is more stable than the conjugated open forms, the merocyanine conformers are significantly stabilized by protonation, electron attachment, and ionization. For protonation on the pyran oxygen atom and electron attachment, the MC conformers are more stable than SP, and unlike for the neutral species, the ring opening is spontaneous at room temperature. Moreover, for the pyran oxygen-protonated form, the ring opening to the cis-merocyanine becomes barrierless. On the other hand, barriers comparable to the neutral remain along the thermal pathway to the cis-merocyanine conformer for ionization or electron attachment, and the barrier for isomerization is significantly higher for the N-protonated SP form. External field effects on the neutral reaction path show that ring opening to the cis-merocyanine is favored when the field reduces the electron density on the pyran part, as also induced by the local field due to O protonation.     

Codense and completely codense ideals

Summary We characterize codense and completely codense ideals.