The Influence of Modes of Deposition of Coatings on the Corrosion Resistance of Welded Joints of Steels in Acidic Media

In this work, effect of welding on corrosion of welded joints of austenitic steel 12KH18N10T. It is shown that the use of pulsed - arc welding steel 12KH18N10T allows you to create a protective coating with dispersed structure with less thermal impact on the zone of the welded joint. Coating is of such structure allows 1.5 to 6 times to reduce the corrosion rate of welded joints of steel 12KH18N10T in active chemical environments. Pulse the process of deposition of coatings on welded joint of steels can be effectively used for the protection against corrosion in the repair of equipment of chemical industry. The results obtained can be recommended for use when welding a protective corrosion - resistant coatings on working surfaces of equipment of chemical productions

Anharmonic coherent dynamics of the soft phonon mode of a PbTe crystal

We investigate the ultrafast optical response of PbTe to an intense single-cycle terahertz pulse, resonant with the soft transverse optical (TO) phonon mode of the crystal. We detect multifrequency oscillations of the reflectance anisotropy, which we associate with nonlinear motion of the TO phonon oscillator excited directly by the terahertz pulse. Our observation of monotonically decaying optical anisotropy together with second harmonic oscillations of the TO mode is an evidence of a transient non-centrosymmetric state of the crystal lattice that can be accompanied by the ferroelectric order. We suppose that this state is induced in the PbTe crystal by the intense terahertz pulse via alignment of the local polar nanodomains. This hypothesis is partially supported by the observation of coherent phonons near the satellite phonon mode frequency that are impulsively generated by a femtosecond laser pulse and are considerably enhanced by a synchronous terahertz pulse.Comment: 7 pages, 5 figure

Excitation of planetary electromagnetic waves in the inhomogeneous ionosphere

In this paper we develop a new method for the analysis of excitation and propagation of planetary electromagnetic waves (PEMW) in the ionosphere of the Earth. The nonlinear system of equations for PEMW, valid for any height, from D to F regions, including intermediate altitudes between D and E and between E and F regions, is derived. In particular, we have found the system of nonlinear one-fluid MHD equations in the β-plane approximation valid for the ionospheric F region (Aburjania et al., 2003a, 2005). The series expansion in a "small" (relative to the local geomagnetic field) non-stationary magnetic field has been applied only at the last step of the derivation of the equations. The small mechanical vertical displacement of the media is taken into account. We have shown that obtained equations can be reduced to the well-known system with Larichev–Reznik vortex solution in the equatorial region (see e.g. Aburjania et al., 2002). The excitation of planetary electromagnetic waves by different initial perturbations has been investigated numerically. Some means for the PEMW detection and data processing are discussed

Development of Transgenic Sorghum Plants with Improved In Vitro Kafirin Digestibility

Improvement of nutritional value of crops is one of the main goals of plant biotechnology. These studies are extremely important for sorghum—a unique drought‐tolerant cereal crop that is of special importance for sustainable grain production in the arid regions. The major cause of relatively low nutritive value of sorghum grain is the resistance of one of its seed storage proteins, γ‐kafirin, to protease digestion. Using Agrobacterium‐mediated genetic transformation, we have obtained transgenic sorghum plants harboring a genetic construct for RNA interference (RNAi) silencing of the γ‐kafirin gene. In T1 generation, transgenic plants with modified endosperm texture were found. These plants had lowered level of the 28‐kDa γ‐kafirin protein and kafirin oligomers, which are formed by natural kafirin polymerization. In vitro protein digestibility analysis showed that the amount of undigested protein in transgenic plants was reduced by 2.9–3.2 times, in comparison with the original line, the digestibility index reached 85–88% (60% in the original line). HPLC analysis showed that total amino acid content in transgenic plants was reduced, while the lysine proportion was increased by 1.6–1.7 times. PCR analysis confirmed inheritance of the genetic construct up to T4 generation

Atmospheric waves disturbances from the solar terminator according to the VLF radio stations data

The perturbations from the solar terminator in the range of acoustic-gravity waves (AGWs) periods from 5 minutes to 1 hour were analysed with the use of measurements of VLF radio signals amplitudes on the European radio path GQD--A118 (Great Britain--France). These observations provide information on the propagation of waves at altitudes near the mesopause ($\sim$ 90 km), where VLF radio waves are reflected. On the considered radio path a systematic increase in fluctuations in the amplitudes of radio waves was observed within a few hours after the passage of the evening terminator. For April, June, October 2020 and February 2021 events, the distribution of the number of wave perturbations with large amplitudes over AGWs time periods has been studied. Our results show that the evening terminator for different seasons is dominated by waves in the range of periods of 15--20 minutes. The amplitudes of the AGWs from the terminator at the heights of the mesosphere (fluctuations in the concentration of neutral particles, velocity components and vertical displacement of the volume element) are approximately determined by the fluctuations of the amplitudes of the VLF radio signals. The amplitudes of the AGWs on the terminator are 12--14\% in relative concentration fluctuations, which correspond to the vertical displacement of the atmospheric gas volume of 1.1--1.3 km. Based on the analysis of the AGW energy balance equation, it was concluded that the waves predominantly propagate in a quasi-horizontal direction at the terminator. The possibility of studying the long-term changes in the mesosphere parameters using fluctuations in the amplitudes of VLF radio waves at the terminator is shown