Effect of the swirl of cocurrent high-velocity air flow on the geometry of an aluminum-air flame

Experimental data characterizing the swirl parameter and nozzle design effects on the recirculation zone dimensions, temperature, and length of an aluminum-air flame are presented.     

Strengthening Particle Size Effect on Residual Stresses in Dispersion-Hardened Alloy

Russian Physics Journal - The paper carries out research into elastoplastic unloading using methods of plasticity theory and solids mechanics. Residual stresses are calculated in a heavy-walled...     

Elastoplastic Deformation of Dispersion-Hardened Aluminum Tube Under External Pressure

Russian Physics Journal - The paper presents research into elastoplastic deformation of a heavy-walled tube made of a dispersion-hardened aluminum alloy, subjected to the external pressure....     

Cobalt hydroxides immobilized on ionites as catalyst for water-to-oxygen oxidation

A way of preparation of dioxygen-evolving catalysts by immobilization of cobalt compounds on ion-exchange resins is proposed. Immobilized cobalt hydroxides are more selective in the reaction of water-to-oxygen oxidation than massive ones and, when prepared as mixture with Al(III), Fe(III), Sn(IV) or Ce(IV), they become even more selective.

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. , , Al(III), Fe(III), Sn(IV), Ce(IV) .

     

Kinetics and mechanism of the reactions of C6H12, C5H10 and C6D12 cycloalkanes with peroxynitrous acid in aqueous solution and the gas phase

The c-C₆H₁₂/c-C₆D₁₂ kinetic isotope effect (KIE), the k₆/k₅ rate constant ratio (c-C₆H₁₂/c-C₅H₁₀), and the temperature dependence of these ratios in the gas-phase reactions of cycloalkanes with peroxynitrous acid and OH radicals are identical. The same result was obtained for the reactions in aqueous solution. These data are in accord with the conclusion that OH^· radicals formed in the homolysis of the HO-ONO bond are the active species in the reactions of HOONO with hydrocarbons in aqueous solution and in the gas phase. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 44, No. 2, pp. 105–110, March–April, 2008.     

Mercury speciation in environmental solid samples using thermal release technique with atomic absorption detection

A sensitive and very simple method for determination of mercury species in solid samples has been developed involving thermal release analysis in combination with atomic absorption (AAS) detection. The method allows determination of mercury(II) chloride, methylmercury and mercury sulfide at the level of 0.70, 0.35 and 0.20 ng with a reproducibility of the results of 14, 25 and 18%, respectively. The accuracy of the developed assay has been estimated using certified reference materials and by comparison of the results with those of an independent method. The method has been applied for Hg species determination in original samples of lake sediments and plankton.     

Magnetic and luminescent properties of copper-deficient Cu1–x(In0.7Ga0.3)Se2 (0 < x ⩽ 0.32) solid solutions with chalcopyrite structure

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Rate constants and isotope effects for the reaction of H-atom abstraction from RH substrates by PINO radicals

The kinetics of the reactions of hydrogen atom abstraction from the C–H bonds of substrates of different structures by phthalimide-N-oxyl radicals is studied. The rate constants of this reaction are measured and the kinetic isotope effects are determined. It is shown that in addition to the thermodynamic factor, Coulomb forces and donor–acceptor interactions affect the reaction between phthalimide-N-oxyl radicals and substrate molecules, altering the shape of the transition state. This favors the tunneling of hydrogen atoms and leads to a substantial reduction in the activation energy of the process.     

Kinetics and Quantum-Chemical Modelling of the Arylation of Aniline and Piperidine by N-Polynitroarylpyridinium Salts

N-Picryl-4-[4-(dimethylamino)styryl]pyridinium salt anions catalyze S _NAr reactions with aniline in acetonitrile. The anion activity increases with increasing basicity. A stepwise substitution mechanism involving the salt anions is confirmed by MNDOd and PM3 semiempirical calculations of the change in free energy of the individual reaction steps of N-polynitrophenylpyridinium chlorides with aniline and piperidine.