The study was conducted of the dynamics of large-scale structures of the polar region F2, due to the change of the sign of the By-component of the interplanetary magnetic field. It is shown that one of the reasons for non-stationary variations of the ionosphere structure in polar caps can be fast variations of the By-components of MMP. The time of transfer of the ionization language from morning to evening is 3000 s. This process is accompanied by the stratification of the ionization language and the formation of large-scale ionization spots that disintegrate over time.

Keywords: polar ionosphere, convection, the electron concentration, interplanetary magnetic field, the helio-geophysical conditions, ionospheric disturbances, polar cap, By - component of MMP, the F-layer

The results of experiments on the Moscow – Ekaterinburg highway are discussed. The principal possibility of using broadband (150-600 kHz) HF signals for transmitting information and for studying the fine structure of the ionosphere in various heliogeophysical conditions is shown.

Keywords: broadband signal, ionosphere, fine structure, noise resistance, operational forecast, information transfer, multiple-beam structure, separation of signals, base frequencies, signal attenuation, long-term prediction

The article provides an overview of the sources with the results of the study of arc welding processes, justifies the relevance of studies of the radial distribution of current density in the anode spot of the plasma arc. The results of the study of the radial distribution of the current density across the active spot on the plane water-cooled probes, which are one of the arc electrodes, and the results of studies of the conversion of the plane probe data into the radial distribution of an axially symmetric function are presented. The radial current density distribution functions and the current density distribution characteristics are experimentally obtained.

Keywords: plasma welding, control system, current-voltage characteristic, shielding gas, burner circuits, plasma arc, sounding

In the framework of simple volumetric models of electron concentration in the F layer of the polar ionosphere, the influence of non-stationary convection on the state of radio paths in high latitudes is considered. Calculations of three-dimensional trajectories of HF-radio beams showed a significant difference for quiet and disturbed conditions

Keywords: ionosphere, refraction, convection, plasma, radio beams, high latitudes

The necessity of studying the thermal balance of electrons in the ionospheric sporadic E layer to clarify the conditions of its formation in the framework of the theory of the wind shear. The method of calculation of the altitude profile of electron temperature in the sporadic E layer of the ionosphere. Reported satisfactory agreement between the calculated profile of the temperature of the eiectrons and its experimental profile.

Keywords: ionosphere electron, temperature, sporadic layer, heat balance, the heating rate, wind shear, altitude profile of the temperature probe measurements

The use of low-temperature plasma in industry and the social sphere is given serious attention in Russia and abroad. Plasma technologies are environmentally friendly and allow solving the problems of resource saving and energy saving. The article is devoted to the search for directions for using low-temperature plasma and the creation of appropriate technologies and equipment in industry and the social sphere. Based on the analysis of scientific, technical and patent information, the opinion was expressed that the potential of low-temperature plasmas in forestry and in the timber industry is underestimated

Keywords: Low-temperature plasma, industrial and social applications, forest seeds, pre-sowing treatment

The technique of calculation of high-altitude temperature profile of electrons in the region E of the ionosphere of the Earth consided. Presented examples of the calculation of the profile of the electron temperature at altitudes of 100 - 170 km, depending on solar Zenith angle given. Discusses the problems of the heat balance of the ionospheric electrons of Earth.

Keywords: ionosphere electron temperature, concentration, heat balance, the heating rate, solar radiation, collisions of electrons, high-altitude temperature profile, probe measurements

The method of calculating the heat flow to the ionospheric electrons from photoelectrons resulting from ionization of the neutral atmospheric components by solar radiation in region E of the ionosphere of the Earth is considered . Examples of the calculation of the spectra of photoelectrons and the rate of heat influx to the electron gas at an altitude of 130 km, depending on solar Zenith angle.

Keywords: solar radiation spectra of photoelectrons, the zenith angle of the sun, the collision of electrons, the ionization potential, secondary ionization, effective absorption cross section

We consider the technique for calculating the spectra of primary photoelectrons generated by ionization of neutral components of the atmosphere by solar radiation in the area E of the Earth's ionosphere. Examples of the calculation of the photoelectron spectra at altitudes (100 - 130) km, depending on the solar zenith angle to the average level of solar activity are shown.

Keywords: solar radiation spectra of photoelectrons, the zenith angle of the sun, the collision of electrons, the ionization potential, secondary ionization, effective absorption cross section.