Generalized trends in the formation energies of several families of perovskite oxides (ABO3) and plausible explanations to their existence are provided in this study through a combination of DFT calculations, solid-state physics analyses and simple physical/chemical descriptors. The studied elements at the A site of perovskites comprise rare-earth, alkaline-earth and alkaline metals, whereas 3d...

The bioaccumulation of alkali and alkaline earth metals such as Na, K, Ca and Mg were studied in the fry of rohu, Labeo rohita (Ham.), a species of freshwater aquaculture importance in India. The experiments were conducted in laboratory conditions exposing the rohu eggs up to fry stage in one experiment; and fry to advanced fry stage in other experiment, to different concentrations of the salts...

A simple and economic separation and speciation procedure for selenium in food and water samples have been presented prior to its graphite furnace atomic absorption spectrometry (GFAAS). Magnesium hydroxide coprecipitation system for selenium(IV) was applied to the separation and speciation of selenium ions. The influences of the various analytical parameters for the quantitative recoveries of ...

The article presents the results of studies hydrochemical composition five urban lakes Murmansk. It was found that chemical water studied is significantly different from northeastern part Murmansk region Barents Sea catchment, which taken as background. pH values have increased in comparison with background values, well mineralization, content major ions, nutrients, and heavy metals. An increas...

A solid phase collection/concentration method using anion exchanger filters and a small syringe packed with chelating resin fibers is adopted as a preconcentration tool for trace elements and a separation tool for matrices in aqueous samples prior to the measurement by inductively coupled plasma-mass spectrometry (ICP-MS). The effects of fiber volume, sample volume, eluent volume, and sample fl...

The properties of field electron emitters made iridium and rhenium, whose surface is coated with carbon by decomposition benzene molecules on the surface, are studied. stability emission characteristics obtained to adsorption residual gas ion bombardment shown. coating either in form a monoatomic graphene film flat faces emitter, or graphite growths. localized edges corners faceted outgrowth. A...

The structures of isolated alkaline earth metal cationized amino acids are investigated using infrared multiple photon dissociation (IRMPD) spectroscopy and theory. These results indicate that arginine, glutamine, proline, serine, and valine all adopt zwitterionic structures when complexed with divalent barium. The IRMPD spectra for these ions exhibit bands assigned to carboxylate stretching mo...

The interactions of phenazino-crown ether ligands with alkali, alkaline earth and selected toxic species were investigated using density functional theory modelling by employing B3PW91/6-311G ++ (d, p) level of theory. The complex stability was analysed in terms of binding energies, perturbation energies, position of highest molecular orbital and energy gap values. In general, the complexes for...

The approaches to get lifetimes of the hexagonal metals have been performed making use of the face centred cubic (f.c.c.) structure, instead of the real hexagonal one. Although some structural reasons allow this approximation, it is expected to fail when free volume is created in the solid. In this work, we have used the real hexagonal geometry to study these metals. For the cases of bulk, mono...