Effect of the anionic composition and pH on the dissolution kinetics of chromium(III) oxide and chromium(III) hydroxide oxide in acids

Based on an experimental investigation of the effects of the pH and anionic composition on the dissolution rate of chromium(III) oxide α-Cr₂O₃ and chromium(III) hydroxide oxide α-CrOOH and subsequent modeling of the process, it is demonstrated that, depending on the pH, the rate-controlling stage of the dissolution is the CrOH²⁺ or CrHSO ₄ ²⁺ sobulization.     

Preparative fractionation of cerebral gangliosides with the aid of ion-exchange chromatography on Spheron CH 300

A new preparative method is proposed for the separation of natural mixtures of gangliosides into fractions of mono-, di-, and trisialogangliosides which is based on ion-exchange chromatography on a weak anion-exchange resin — Spheron CH 300. The latter ensures a considerably faster separation than the ion-exchange resins usually employed.Scientific-Research Laboratory of Biologically Active Substances of Hydrobionts, USSR Ministry of Health, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 28–30, January–February, 1990.     

Measuring Contact Angles at Copper Electrodes

Potential dependences of the angle of contact between perfluorodecaline C₁₀F₁₈ and copper, copper(I) sulfide, and copper telluride Cu₄Te₃ in 0.1 M CH₃COONa are measured. The data are in good agreement with the metal hardness measured in 1 M KOH. The uncharged-surface potentials (USP) for copper, copper(I) sulfide, and copper telluride equal 0.05–0.07, –0.02 to –0.04, and 0.05–0.07 V (NHE) in 0.1 M CH₃COONa. Studying the effect of Br^– ions shows that USP for copper and Cu₂S shift in, respectively, the negative and positive directions with an increase in [Br^–]. For copper telluride, USP shifts in the positive direction at low Br^– concentrations, and at NaBr concentrations in excess of 0.04 M, in the negative direction.     

The Concept of a Hybrid Pulsed Plasma Thruster for Small-Size Space Satellites

Russian Physics Journal - A concept of a hybrid plasma source to be used as a micro satellite thruster is proposed, where the propellant is a liquid gallium–indium alloy. The plasma source...     

Peculiarities of the Short-Pulse Dielectric Strength of Vacuum Insulation

Russian Physics Journal - Results of a study of the short-pulse dielectric strength of millimeter plane vacuum gaps with electrodes that have been treated with an electron beam are presented. It is...     

Generation of droplets emitted by pool explosive-emission cathodes

The velocity spectrum of droplets emitted by a pool explosive-emission cathode was studied. Relation between sizes of droplets and its maximal velocities over the range of 10³−18×10⁴ cm/s have been found. The dependence obtained confirms the mechanism found earlier for the droplet emission under high pressures developed in explosive emission centers. Institute of High Current Electronics. Siberian Division of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 105–109, March, 1999.     

A diglyceride uronoside from streptomyces LA 7017

Chemistry of Natural Compounds - A new glycolipid, a 1-O-[4-O-(α-D-glucopyranosyl)-α-D-glucopyranuronosyl]-2,3-diglyceride has been isolated from the total cell lipids of Streptomyces LA...     

Diffraction by an elliptical impedance cylinder

Kharkov State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Radiofizika, Vol. 32, No. 9, pp. 1125–1131, September, 1989.     

Investigation into the erosion of explosive-emission liquid-metalcathodes

The erosion rate has been measured for capillary-type and needle-type liquid-metal cathodes. The erosion drop fraction composition and percentage have been determined. For the needle-type liquid-metal cathodes, the erosion of the core has been discovered and investigated. To describe this erosion, a simple analytical model has been proposed