Splash type mass transfer on the water film at downflow and upflow

Generation of droplets on a surface of the water thin film at upflow and down flow is considered. Expressions for computation of splash type mass transfer were developed.     

The problem of the transmission of energy from an electromagnetic field into a high-frequency discharge plasma

On the basis of a consideration of the interaction between the electromagnetic field and the plasma we determine the power evolved in a discharge as a function of the various parameters of the field, the nature of the gas, and the discharge temperature.From a consideration of the thermodynamical properties we determine the power drawn off by heated gases of the plasma burner as a function of the temperature of these gases and the consumption.Finally, from a consideration of the energy balance we determine the resulting temperature and power of the discharge as a function of the above-mentioned parameters. The results of calculations coincide with the experimentally measured values of the power and discharge temperature.In conclusion the authors would like to express their thanks to Professor S. A. Medvedev for his assistance in discussing the results of this study.     

Microwave-activated lignin conversion to synthesis gas

Russian Chemical Bulletin - The use of the low-power (up to 10 W) microwave activation to heat the reaction mixture in the catalytic oxidative conversion of lignin to synthesis gas results in a...     

Cu-MOF-Catalyzed Carboxylation of Alkynes and Epoxides

The catalytic activity of copper-containing heterogeneous catalysts, in particular metal-organic frameworks, zeolites, and alumina-supported nanoparticles, in the carboxylation of terminal alkynes and oxiranes has been evaluated. Temperature dependences of these reactions have been studied.

     

Association of hydrophilic derivatives of chlorophyll <Emphasis Type="Italic">a</Emphasis> in ethanol–water and ethanol–water–solubilizer systems

Electronic absorption spectroscopy and fluorescence spectroscopy were used to study conditions for the formation of associates of amphiphilic phorbins and chlorins in an ethanol–water system. The conditions and degree of disaggregation in the presence of solubilizing additives of nonionic surfactants (Tween 80) and biocompatible polymers (polyethylene glycol and polyvinylpyrrolidone) were also investigated. The propensity of the macroheterocycles based on chlorophyll a to association in water-alcoholic solutions decreases on going from covalently bound dimeric structures to monomeric ones, on going from phorbins to chlorins and on accumulating hydrophilic glycol or positively charged alkylammonium fragments in the molecule. Among the considered solubilizers, the nonionic surfactant Tween 80 emerged as the most efficient means for destroying chlorin associates in water–alcohol solutions with a high content of water.     

The Oxidation of Carbon Monoxide as an Integrated Part of the Coupled Alkane Oxidation Process: Gas-Phase Oxidation over Supported Metal-Complex Catalysts

Heterogeneous rhodium–copper chloride catalysts for gas-phase oxidation processes were prepared via the cold impregnation of γ-Al₂O₃ with aqueous RhCl₃ and CuCl₂ solutions. Heptafluorobutyric or pentafluorobenzoic acids were additionally deposited onto these catalysts to simulate the action of homogeneous rhodium–copper chloride catalytic systems in the coupled alkane–carbon monoxide oxidation reaction. The catalysts were studied in the reactions of carbon monoxide oxidation and coupled propane–CO oxidation with dioxygen by diffuse reflectance IR Fourier transform spectroscopy (DRIFTS) and electron paramagnetic resonance (EPR). The obtained data indicate the probable transfer of electrons between rhodium and copper compounds.     

Selective Hydrogenation of Acetylene and Physicochemical Properties of Pd–Fe/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Bimetallic Catalysts

The selective hydrogenation of acetylene on Pd–Fe/Al₂O₃ catalysts prepared by decomposition of ferrocene on reduced Pd/Al₂O₃ was studied. The effect of the conditions of treatment of the Pd–ferrocene/ Al₂O₃ precursor on the catalyst activity and selectivity was investigated, and the optimum conditions were determined at which the Pd–Fe/Al₂O₃ catalyst has higher selectivity than Pd/Al₂O₃ without any loss of activity.