Influence of Preparation Conditions on Properties of a Copper-Containing Catalyst for Electrocatalytic Oxidation of Acetone

Stages of synthesis of a copper-containing catalyst for electrocatalytic oxidation of acetone in waste gases were studied. The course of the extrusion and calcination and their influence on electrocatalytic oxidation of acetone on the catalyst synthesized were analyzed.     

X-ray studies of supported copper-aluminium catalysts

Structural peculiarities of the formation of copper-aluminium catalysts at copper concentrations <10 wt% and calcination temperatures of 573–1173 K have been studied.

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<10% . 573–1173°K.

     

Plasma-Enhanced Catalytic Oxidation of Carbon Monoxide

Data on the kinetics of plasma-enhanced and plasma-enhanced catalytic oxidation of carbon(II) oxide with IK-1-6 catalyst are presented. The influence exerted by IK-1-6 catalyst on the conversion of carbon-containing components of the CO-CO₂-CH₄-SO₂-air gas mixture in barrier-discharge plasma is analyzed.     

Unsteady propagation of longitudinal shear cracks

In all problems of unsteady crack propagation which have been solved to date [1 to 3], it has been assumed that the crack propagates at a constant speed. This assumption was not prompted by physical considerations of the problem, but by the methods of solution, therefore, the applicability of the results is limited. It would be more realistic to consider the speed of crack propagation as a function of time based on explicit physical hypotheses. Unfortunately, the general case of the resultant problem cannot be solved by existing methods. However, the problem of longitudinal shear cracks i.e. the plane problem in which the displacement is parallel to the crack boundary, may be solved for an arbitrary given variation in crack propagation speed, utilizing the method developed in connection with the theory of supersonic flows [4 and 5].

Note that equilibrium problems of longitudinal shear cracks have been studied in [6 and 7].     

Diagnostics of the atmospheric-pressure plasma parameters using the method of near-field microwave sounding

A method of resonant near-field microwave probing is developed for contactless diagnostics of a high-pressure plasma. The efficiency of this method in measuring the parameters of the plasma of an rf capacitive discharge in argon under atmospheric pressure is demonstrated. The experimental results are compared with the data obtained using the independent method, the microwave radiation “cutoff,” and with theoretical estimates.     

Compression of whistler waves in a plasma with a nonstationary magnetic field

We present the results of our experiments in which the propagation of whistler waves in a plasma with a nonstationary magnetic-field perturbation (B=B₀+δB(t), δB/B₀ ≤ 5%) was investigated. The parametric and dispersive phenomena in a variable magnetic field were studied on the unique Krot plasma bench (the plasma column was 4 m in length and 1.5 m in diameter). A periodic field perturbation is shown to lead to an amplitude-frequency modulation of the whistler wave and to fragmentation of the signal into separate frequency-modulated wavepackets followed by their compression. The formation and compression of pulses is attributable to strong whistler group-velocity dispersion near the electron cyclotron frequency (ω ≤ ω_H). The results can be used to interpret the spectral shapes of the signals received from the Earth’s magnetosphere and ionosphere in the electron and ion whistler frequency ranges.     

Kinetics of chromium(VI) adsorption from model solutions on iron oxide

Adsorption of Cr(VI) on Fe₂O₃ from model solutions with various Cr(VI) concentrations was studied. The adsorption capacity was determined, the constants of chromium(VI) adsorption on iron(III) oxide for the pseudo-second-order model were calculated, and the diffusion coefficients for the process were evaluated.     

Influence of nonlinear effects on whistler emission in magnetoactive plasma

The influence of thermal and strictional nonlinear effects on the whistler emission in magnetoactive plasma is studied experimentally. It is established that a nonlocal thermal nonlinearity determines the directional pattern of the antenna, while a strictional nonlinearity, which is strongest near the antenna surface, is responsible for the matching of the emitter with the surrounding plasma. Pis’ma Zh. éksp. Teor. Fiz. 67, No. 8, 548–551 (25 April 1998)     

Parametric generation of low-frequency waves by plasma electrons accelerated under electron cyclotron resonance conditions

It has been shown experimentally that the diamagnetic effect appearing when electrons of a magnetized plasma in the antenna near field are accelerated under electron cyclotron resonance conditions can be used to generate low-frequency waves. The amplitude modulation of a signal supplied to the antenna is accompanied by the modulation of the diamagnetic effect and leads to the emission of waves at the modulation frequency to the surrounding plasma. In this process, the extended plasma region containing accelerated electrons serves as a parametric bodiless antenna. The results of the model laboratory experiments make it possible to propose a method for the parametric generation of low-frequency whistler waves in the Earth’s ionosphere by a powerful amplitude-modulated signal supplied to the satellite-borne antenna.     

Features of Wave Propagation in an Inhomogeneous Plasma near the Electron Cyclotron Resonance

JETP Letters - Features of the propagation of electromagnetic waves in an inhomogeneous plasma at frequencies close to the electron-cyclotron resonance have been studied experimentally. It has been...