Combustion in Ni–Al System with Cu Additive (Powder or Rod). Experiment and Mathematical Model

Russian Journal of Non-Ferrous Metals - Experimental studies have been carried out with theoretical calculations of wave synthesis in the Ni–Al–Cu system using a mathematical model....     

Experimental and Forecasting Studies of Bending Characteristics of Contemporary Stiffening Fabrics

Fibre Chemistry - The paper presents the results of experimental and forecasting studies of bending characteristics of contemporary stiffening fabrics made of synthetic threads and mixed yarn...     

Thermal explosion in mechanically activated Ti–C system

Suggested was a mathematical model for a two-stage mechanochemical synthesis of TiC in a mode of thermal explosion. Preliminary mechanical activation of green Ti–C mixtures was found to markedly accelerate the process. Calculated results well agreed with the available experimental data on mechanically activated Ti–4 wt % C mixtures. Using the method of reverse problem and relevant experimental data, we evaluated some kinetic and thermophysical characteristics of mechanochemical synthesis in the Ti–С system.     

On possibility of formation of metastable compounds in a wave of gasless combustion

Suggested and investigated was a mathematical model of gasless solid-flame combustion in two-component green compacts admitting formation of a metastable product. Outlined are the conditions at which the reaction yields either a metastable or stable product. Suggested is a procedure for deriving thermodynamic constants from experimental data.     

The system of the efficient monitoring of air quality in maritime cities and health resort areas: Pollution of the nearwater layer of the atmosphere with sea aerosols

The system of the efficient monitoring of air quality for maritime cities and health resorts has been set up. A basis for the prototype of such a system is establishment of functional links between the concentration of toxic substances in the air and the disperse composition of sea aerosol and the surface of microlayer for every maritime region under hydrometeorological conditions. This provides an opportunity to monitor the chemical composition of sea aerosol by its disperse characteristics and dispersion of the surface film.     

Physicochemical properties and biological activity of the water depleted of heavy isotopes

Data on physicochemical properties of the light water (deuterium concentration is reduced to the ratio D/H = 4 ppm and that of the isotope of oxygen 18—to the ratio ¹⁸O/¹⁶O = 750 ppm) have been obtained. They include the melting and boiling points, kinematic viscosity, density, the spin-spin proton relaxation time, self-diffusion coefficients, and the small-angle laser light scattering. It was found out that the biological activity of the light water was determined by the mechanisms different from the ligand-induced toxic effects. An explanation was proposed for the detected significant changes of the light water as compared with the high-resistivity water having geochemically ordinary isotope composition. This explanation was based on the mechanism of formation of supramolecular density inhomogeneities in water representing the deuterium-stabilized heterophase clusters.     

Structure of a catalytically active octanuclear cobalt complex [Co(II)4Co(III)4(μ4-O)4(μ-O2CPh)12(PhCOOH)4]

The structure of a catalytically active octanuclear mixed-valence cobalt complex [Co(II)₄Co(III)₄(μ₄-O)₄(μ-O₂CPh)₁₂(PhCOOH)₄] (Ph = phenyl, C₆H₅) has been determined using an X-ray diffraction analysis. The presence of 16 ligands containing phenyl rings in each complex gives rise to strong steric stresses and leads to a disordering of terminal groups. The compound crystallizes in the monoclinic crystal system, space group of symmetry P2₁/n, with the unit cell parameters a = 18.076(5) ?, b = 26.371(3) ?, c = 22.791(5) ? β = 92.48(1)°, V = 10853(4) ?³, Z = 4, and ρ = 1.516 g/cm³. The final values of the discrepancy factors are R1 = 0.0441 for 4005 symmetrically nonequivalent reflections with I ≥ 2σ(I), wR2 = 0.1131, and GooF = 0.943.     

Investigation of the crystallization of zeolites in the SiO2-Al2O3-Na2O-K2O-(TEA)2O-H2O system

The crystallization of zeolites in the SiO₂-Al₂O₃-Na₂O-K₂O-(TEA)₂O-H₂O system, where (TEA)₂O is tetraethylammonium oxide, has been investigated over a wide range of variations in the SiO₂: Al₂O₃ ratio (from 5 to 19). It has been found that, in the composition region under investigation, zeolites crystallize with structures of paulingite, beta, phillipsite, merlinoite, erionite, mordenite, and garronite. The formation of the aforementioned phases is determined by the composition of the initial gels and the synthesis temperature. The cocrystallization of paulingite, phillipsite, and merlinoite is explained by the structural features of these zeolites.     

A correlation leak detector with a vertical antenna array for seeking leaks in underwater pipelines

A correlation method for localizing leaks in underwater pipelines using a two-element vertical antenna is considered. The main calculation relationships were obtained and estimates of the error of this method are presented.     

Estimation of kinetic constants for reactions in thin films

The problem of synthesizing a product in thin films taking into account a finite reaction rate at the phase boundaries is considered. Formulas are derived that determine the dynamics of synthesis in the diffusive regime and in the regime controlled by the boundary kinetics. Based on these formulas, procedures are proposed for estimating the parameters of the boundary kinetics.