Selected mixtures in 2 l binary and 9 ternary rare-earth oxide syste ms were studied by X-ray diffraction after heat treatment aL 1,650° C and above. Two graphs were drawn to show specific r egions of stability for t he various strucLure types. Each givcs t he a verage ionic rad ius of constiLuent cations versus the mole percent of the smaller cation. One diagram is es~e ntiall :-' divided inLo...

Alkali halides and alkaline earth halides are strongly ionic compounds that solidify as crystals. The name for the alkali elements (Li, Na, K, Rb and Cs) comes from the Arabic word alqili (ashes of the salt-wort plant that was once used as a source of sodium and potassium for making glass from sand). The name for the halogen elements (F, Cl, Br, I—and the rare radioactive element astatine) come...

Among numerous sources emitting pressure waves a few are known to generate acoustic signals both in the earth, as seismic waves, and in the atmosphere, as infrasound, which were recorded over large distances. Those sources are near surface phenomena like volcanic eruptions, explosions, and ocean waves, which all occur at the boundary between the solid earth and the atmosphere, either shallow ab...

The Earth is undergoing an accelerated rate of native ecosystem conversion and degradation and there is increased interest in measuring and modelling biodiversity from space. Biogeographers have a long-standing interest in measuring patterns of species occurrence and distributional movements and an interest in modelling species distributions and patterns of diversity. Much progress has been mad...

a single column cation exchanger resin was used to eliminate cations from renet cheese whey, with particular reference to the improvement of taste and flavor. ten panelists were convened to assess the contribution of the mineral components to the salty taste of whey, judging on the basis of taste, flavor and color. the organoleptic characteristics of untreated whey were arbitrarily assigned...

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...

It is well known that graphite has a low capacity for Na but a high capacity for other alkali metals. The growing interest in alternative cation batteries beyond Li makes it particularly important to elucidate the origin of this behavior, which is not well understood. In examining this question, we find a quite general phenomenon: among the alkali and alkaline earth metals, Na and Mg generally ...

The high-performance separation of alkaline earth and transition metal ions on a bare porous silica 10.0 cm× 0.46 cm monolith (Merck Chromolith Si) was achieved using solvent enhanced ion chromatography. Using acetonitrile or methanol based ammonium and sodium acetate buffered mobile phases, the effect upon cation retention of mobile phase ionic strength, organic content and pH were evaluated. ...

The practical applications of perovskite hollow fibers (HFs) are limited by challenges in producing these easily, cheaply, and reliably. Here, a one-step thermal processing approach is reported for the efficient production of high performance perovskite HFs, with precise control over their cation stoichiometry. In contrast to traditional production methods, this approach directly uses earth-abu...

Macropolycyclic ligands containing appropriate binding sites and cavities of suitable size and shape, may be designed so as to display molecular recognition in the formation of selective inclusion complexes, cryptates, with metal cations, but also with anions and molecules. Macrobicyclic ligands B form highly stable and selective alkali and alkaline-earth cryptates, displaying a pronounced cryp...