Chemoselective hydrogenation of 3-nitrostyrene over Ag/TiO2-SiO2 catalyst in a flow reactor

1. Download : Download high-res image (76KB)
2. Download : Download full-size image

     

Vacuum ultraviolet spectra of heteronuclear dimers of inert gases in a direct-current discharge

The emission bands appearing near the resonance lines of Kr and Xe in the spectra of the gas-discharge plasma of binary Xe-X and Kr-Y mixtures (X is He, Ne, Ar, or Kr; Y is He, Ne, or Ar) are experimentally studied. It is concluded that the emission bands investigated are related to electronic transitions in hetero-nuclear dimers. The mechanisms of formation of the spectra under study are analyzed.     

Photoelastic Method for Analyzing Residual Stresses in Compact Disks

The issues of size and shape stability are especially important in modern high technologies, in particular, in the compact disk technology. Stability in this case is substantially affected by residual stresses that occur in disks because of the imperfection of their production process. The objective of the present study was to develop a simple optical method to estimate the stress state of compact disks.     

Distribution of C60 and C70 fullerenes in the extraction system (C60 + C70)-α-pinene-ethanol-H2O

The distribution of C₆₀ and C₇₀ fullerenes in the extraction system (C₆₀ + C₇₀)-α-pinene-ethanol-H₂O was studied at constant C₆₀ to C₇₀ ratio and variable total fullerene concentration at 25°C. The relationship between the C₆₀ and C₇₀ content in ethanol (I) and α-pinene (II) phases is nonlinear over the entire fullerene concentration range.     

Simulation of the Behavior of Dioxins under the Conditions of Electron-Beam Gas Cleaning of Sulfur and Nitrogen Oxides

The efficiency of the electron-beam treatment of gases for the removal of sulfur and nitrogen oxides was examined as applied to dioxins. The gas-phase and liquid-phase degradation of dioxins and the oxidation of condensed carbon to form dioxins were taken into account in a model for the behavior of dioxins under the action of ionizing radiation. It was found that the formation of dioxins can significantly decrease the removal efficiency. Under certain conditions, the initial concentration of dioxins can increase.     

Homogeneous and heterogeneous radiation induced NO and SO2 removal from power plants flue gases-modeling study

The generalized mathematical model has been developed for radiation induced removal of NO and SO₂ from flue gases of power plants. This model includes energy absorption of electron beam with active species generation, reactions in gas phase, aerosol formation and growth, and liquid-phase chemistry. To investigate the role of various process parameters (initial NO and SO₂ concentrations, temperature, humidity, absorbed dose) a number of numerical calculations has been carried out. Computer modeling results are in good agreement with reported experimental data.     

Sorption of water by poly(vinyl alcohol)

The isotherms of water sorption by poly(vinyl alcohol) have been obtained by static sorption methods in a wide range of vapor activities. The properties of poly(vinyl alcohol) at various values of relative humidity have been studied by DSC, X-ray diffraction analysis, and mechanical testing. It has been shown that the correct thermodynamic analysis of sorption isotherms for sorbents with complex organization requires knowledge of their structural features. A method of allowing for the effect of osmotic pressure on the polymer sorption capacity is proposed. The pair interaction parameters estimated in this study are compared with the published data.     

Vaporization and thermodynamic properties of the PbO-V2O5 system

The vaporization of individual lead and vanadium oxides and a wide range of compositions of PbO-V₂O₅ melts has been studied. The thermodynamic characteristics of the PbO-V₂O₅ system have been determined, PbO-V₂O₅ melts show negative deviations from the ideal behavior because of the formation of thermally stable compounds in their condensed phase. For gaseous lead vanadate PbV₂O₆, the thermodynamic functions have been calculated and the standard enthalpies of formation and atomization have been determined.     

The kinetics of phase transition in systems with nonconservative order parameter

The kinetics of ordering in systems described by the nonconservative order parameter is studied near the second-order transition critical point.On leave fromDepartment of Nuclear Physics and Biophysics, Faculty of Natural Sciences, University of P. J. afárik, Moyzesova 11, 041 67 Koice, Czechoslovakia.     

Condensation of unsaturated cyclic sulfones with aldehydes

The reactivity of the 2(5) positions of dihydrothiophene dioxide has been studied. Their condensation with aldehydes leads to the formation of 2(5)-substituted derivatives containing a conjugated system of double bonds.