V. V. Azharonok

Fungicidal Effects of Plasma and Radio-Wave Pre-treatments on Seeds of Grain Crops and Legumes

An influence of RF plasma and RF electromagnetic field pre-treatments on level of fungal infection of some important agricultural plants has been studied. It is shown that pre-sowing plasma and radio-wave seeds treatments contribute to their germination enhancement and plant productivity improvement owing to stimulative and fungicidal effect of plasma and RF electromagnetic field irradiation.

The effect of the high frequency electromagnetic treatment of the sowing material for legumes on their sowing quality and productivity

The effect of a low-intensity radio wave (5.28 MHz) electromagnetic field on the seeds of annual and perennial legumes has been investigated. It has been shown that the presowing electromagnetic treatment of the seeds with a duration of 10–15 min contributes to their laboratory and arable germination enhancement, survival, and crop capacity increase and can be considered as a mediator of the seeds’ cell receptors that initiate intracellular mechanisms that lead to the improvement of the seeds’ sowing quality.

Response of perennial woody plants to seed treatment by electromagnetic field and low-temperature plasma

Radiofrequency (5.28 MHz) electromagnetic radiation and low-temperature plasma were applied as short-term (2-15 min) seed treatments to two perennial woody plant species, including Smirnovs rhododendron (Rhododendron smirnowii Trautv.) and black mulberry (Morus nigra L.). Potential effects were evaluated using germination indices and morphometry. The results suggest that treatment with electromagnetic field stimulated germination of freshly harvested R. smirnowii seeds (increased germination percentage up to 70%), but reduced germination of fresh M. nigra seeds (by 24%). Treatment with low-temperature plasma negatively affected germination for R. smirnowii, and positively for M. nigra. The treatment-induced changes in germination depended on seed dormancy state. Longer-term observations revealed that the effects persisted for more than a year; however, even negative effects on germination came out as positive effects on plant morphometric traits over time. Treatments characterized as distressful based on changes in germination and seedling length increased growth of R. smirnowii after 13 months. Specific changes included stem and root branching, as well as increased leaf count and surface area. These findings imply that longer-term patterns of response to seed stressors may be complex, and therefore, commonly used stressor-effects estimates, such as germination rate or seedling morphology, may be insufficient for qualifying stress response. Bioelectromagnetics. 37:536-548, 2016.

Effect of a high-frequency electromagnetic field on the properties of chromium coatings

The results of studying the effect of high-frequency magnetic-pulse treatment of electrodeposited chromium coatings on their structure are described. It is shown that the effect of magnetic-pulse treatment depends on the deposition conditions, which are responsible for significant changes in the initial structure and microhardness of the coatings.

Structural changes in CЧ-25 cast iron in an amplitude-modulated high-frequency electromagnetic field

The high-frequency magnetic field influence on changes in the structure and properties of CЧ-25 cast iron obtained by the method of continuous-cycle freeze casting has been studied. It has been found that the structure effects of high-frequency magnetic-pulse action on cast iron are the “healing” of surface defects, perlite dispersion, a decrease in the ferrite content in the structure due to the ferrite-graphite complex transformation into perlite, coarsening and modification of the internal structure of graphite inclusions, and a change in the cementite morphology. The observed structural changes determine the decrease in hardness of automobile parts of the cylinder-piston block.

Changes in the physical and mechanical properties of friction composites with a polymer matrix induced by an amplitude-modulated high-frequency electromagnetic field

This paper presents the results of experimental studies of the influence of a high-frequency electromagnetic field on the physical, mechanical, and tribological properties of polymer friction composites for automotive brakes. It was shown that, in some cases, the treatment with an electromagnetic field results in the transformation of the polymer supramolecular structure. In the case of treatment of initial powder compositions, significant changes (up to 20%) in the dynamic modulus of elasticity and the tribological properties of the final materials were found. The possible mechanisms of the effect of pulsed high-frequency electromagnetic treatment on the physical and mechanical properties of friction materials, as well as the correlation of the properties with the acoustic noise of friction units, are under discussion.

Variation in the structure and properties of cast-iron sealing rings under magnetic-pulse treatment

The variation in the structure and properties of cast-iron sealing rings (content in wt %: 2.8–3.0 Si; 0.4–0.6 Mn; 0.1–0.2 Cr; 0.5–0.6 Ni; 0.7–0.9 Cu; 0.04–0.06 Mg; 2.8–3.0 C) under their exposure to a 5.28-MHz pulsed magnetic field is studied. Variations in the eutectoid morphology, the internal structure of the graphite inclusions, and the size of the free cementite inclusions, which result in the enhancement of the hardness, are observed. The magnetic-pulse treatment of rings induces compression stresses in them. The physicomechanical properties of the rings change periodically upon the variation of the number of treatment cycles. The optimum mode corresponds to two cycles.

Light-induced cooling of active medium of CW TEA CO2 laser

In the present paper a gas kinetic temperature change of active medium of high-power TEA CO2 laser that is conditioned by a self-influence of laser radiation on plasma parameters, is investigated. The active medium was pumped by a self-sustained transverse glow discharge. The gas kinetic temperature Tg of plasma has been deduced from the half-width of rotationally unresolved spectral bands of the (2+)N2. It is shown that the laser radiation propagation through the inverse medium causes a cooling of the active medium. The degree of the gas mixture cooling δTg≈5K at W~2.2 W/2.2 W/cm3 and δTg≈60 K at W~4.4 W/cm3. We suppose that the effect of the active medium cooling is connected with the change of a kinetic of V-T relaxation in asymmetrical mode of the active medium cooling is connected with the change of a kinetic of V-T relaxation in asymmetrical mode of the active medium cooling is connected with with the change of a kinetic of V-T relaxation in asymmetrical mode of vibrationally-excited CO2 molecule when the lasing takes place in the laser resonator. Analytical estimation of light-induced temperature change δT*g of fast-flow TEA CO2-laser active medium are compared with the experimental ones.

Light-Induced Cooling of the Active Medium of a Fast-Circulation CO2 Laser in the Field of Generated Radiation

Using the methods of emission spectroscopy, we studied the influence of generated radiation on heating the active medium of a fast-flow electric-discharge CO2 laser.

Influence of the High‐Frequency Capacitive Discharge Regimes on the Parameters of the Plasma in N2/CO2/He Gas Mixtures

The optical radiation spectra and the spatial structure of a planar high‐frequency capacitive discharge in N2/CO2/He gas mixtures have been investigated depending on the excitation frequency, discharge current, pressure, and chemical composition of the mixture.