Simulation of Convective Flow of an Electrically Conducting Fluid in a Cavity

A new quasi-hydrodynamic algorithm is proposed for numerical analysis of convective flows in the presence of a homogeneous external magnetic field. The Marangoni convection problem in a square cross-section cavity is solved.     

Electrode Processes in a Eutectic KCl–KF Melt Containing Gadolinium Oxide

The electroreduction of gadolinium from a eutectic KCl–KF melt containing 0.210–1.233 wt % Gd₂O₃ on molybdenum and glassy carbon electrodes is studied at 1008 K. The solubility of gadolinium oxide is determined. It is shown that the reduction of a gadolinium oxyfluoride complex proceeds reversibly, with a subsequent reversible chemical reaction. The gadolinium reduction on an iron electrode in a eutectic KCl–KF melt purified of unwanted oxide ion impurities yields an iron-gadolinium alloy.     

Immobilized sol of cobalt(III) hydroxide as an efficient catalyst of water oxidation to dioxygen by the Ru(bpy)33+ complex

Catalysts of water oxidation to dioxygen by Ru(bpy) ₃ ³⁺ have been obtained by immobilization of colloidal Co(III) hydroxide on supports of the hydroxide types. These supports are found to be able either to enhance (Al(III), Bi(III), Sn(IV) and Ce(IV) hydroxides) or to weaken (Fe(III) and Mn(IV) hydroxides) the catalytic efficiency of the initial sol. The possible nature of the influence of the support is discussed.

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Ru(bpy) ₃ ³⁺ Co(III). - , ( Al(III), Bi(III), Sn(IV), Ce(IV)), ( Fe(III), Mn(IV)) . .

     

A chemical study ofPlectranthus glaucocalyx Maxim.

Summary A previously unknown crystalline substance C₂₀H₂₈O₄, calledplectrin, has been isolated from the leaves ofPlectranthus glaucocalyx Maxim., family Labiatae.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 6, pp. 427–428, 1965     

Homogeneous catalysts for dioxygen evolution from water. Water oxidation by trisbipyridylruthenium(III) in the presence of cobalt, iron and copper complexes

Complexes of Co, Cu and Fe with bipyridyl, and cobalt complexes with ammonia, ethylenediamine and oxyacids are shown to be efficient catalysts for water oxidation by Ru(bpy) ₃ ³⁺ in both alkaline and weakly acidic media. Partially hydrolyzed forms of these complexes are assumed to be active.

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, Ru(bpy) ₃ ³⁺ , Co, Cu Fe, , . , .

     

Production of Granulated NaP Zeolite without Binder

Possibility was examined of synthesizing zeolites granulated without a binder with the use of a preliminary ultrasonic treatment of the suspension at a frequency of 22 kHz from mixtures of sodium metasilicate and aluminum and silicon oxides with various Si: Al ratios. It was found that, after the preliminary treatment, extrusion of grains, and calcination at 650°C, crystalline phases Na₆Al₄Si₄O₁₇, Na₈Al₄Si₄O₁₈, Na₂Al₂O₄, and Na₂SiO₃ phases are formed in the sample with Si: Al = 1. These phases are precursors for synthesis of NaA and NaP zeolites and sodalite via hydrothermal crystallization in a NaOH solution with concentration of 2 M. Upon a similar treatment of a sample with Si: Al = 2, there are crystalline phases α- and β-Na₂Si₂O₅, from which only NaP zeolite is formed in the course of crystallization. The hydrothermal crystallization in a 6 M alkali solution yields sodalite, irrespective of the Si: Al ratio. It was shown that an ultrasonic treatment gives a gel-like system at Si: Al = 1 and a powdered material at Si: Al = 2, which yields by the end of synthesis samples with cactus-like or wool-like morphology, respectively.     

Recovery of rare earth elements from wet process extraction phosphoric acid

It is shown that an increase in the recovery of rare earth elements in fluorophosphate concentrates, which are obtained by treating the wet process phosphoric acid by ammonium fluoride, is achieved by prior partial neutralization of H₃PO₄ by ammonia. Therewith the consumption of ammonium fluoride is reduced that provides almost complete precipitation of rare earth elements.     

Reactivity of the Peroxo Complexes of Copper(II) Hydroxide

In the interaction with H₂O₂ in an alkaline medium, Cu(OH)₂ forms terminal Cu–OOH and bridging peroxo complexes with the -1,1 and -²:² structures. It was found that the terminal peroxide is active in the reactions of H₂O₂ decomposition, diphenol oxidation, and nitrile conversion into acid amides. The promoting effect of ammonia on these reactions was found. A possible mechanism is discussed.