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The aim of the research is to obtain wear-resistant products from composite materials of a new type using the SHS technology. The Ti–Cu–C system was selected taking into account the data available in the scientific and technical literature. Various SHS charge compositions consisting of titanium powder, copper powder, and carbon black were experimentally burned to determine compositions that can burn during the SHS process and provide a melt containing titanium carbide and titanium cuprides as a binder featuring higher mechanical properties and lower melting points than pure copper. Model samples of products in the form of bushings with an outer diameter of 70 and 110 mm were produced by burning the SHS charge with selected compositions in a reactor followed by the compaction of the resulting melt with a force of 50–60 t. After the rough workpiece electrical discharge machining, samples were cut out for phase analysis, X-ray spectral analysis, and wear tests. With an optimal ratio of SHS charge components, titanium carbide and a binder in the form of titanium cuprides of different compositions were revealed in the model sample material. Using the method of testing for wear when sliding on a fixed abrasive under a specific pressure of 1 MPa, it was determined that the relative abrasive resistance of the new material at a hardness of 50–52 HRC is 1.8–2.0 units in comparison with the hardened tool and die steel Kh12MFL. In order to implement the technology in practice, an algorithm was developed for calculating the compositions of the newly formulated SHS charge, while its principle is such a ratio of components where the introduced carbon forms titanium carbide with titanium, and the added excess titanium forms titanium cuprides with copper. The developed material can be considered as promising for use as elements of equipment operating under abrasive wear conditions. This development is patented, Patent No. 2691656 (Russian Federation).

One of the most difficult tasks of the analytical control of copper ores is the determination of the mineral forms of copper. Currently, for this purpose, iodometric and atomic absorption methods are used with preliminary leaching of various mineral forms. The disadvantage of those methods is a rather complicated sample preparation procedure and significant time of analysis. The most universal method for determining the mineral composition of solid samples is the X-ray diffraction method. However, significant variations in the phase composition of copper ores, overlapping reflections of different phases, the presence of an amorphous phase and structural defects necessitate the development of special approaches. In this work, the presence of an amorphous phase is taken into account by direct calculation of the mass fractions of crystalline phases by the G-factor method. The total copper content is determined by the X-ray fluorescence method. Methodological approaches based on using only X-ray methods are proposed, which exclude the procedures of leaching and dissolution of samples and provide determination of primary and secondary copper sulfides using calibration characteristics (3 min), and gaining data on the complete phase composition at the stage of routine analysis (10 – 15 min) and for research purposes (15 – 20 min).

The influence of high-temperature quenching and cold treatment on the amount of residual austenite, its stability and ability to deformation martensitic transformation, hardening and wear resistance during the abrasive wear of pearlite grade 150KhNML carbon steel is studied. It is shown that maximum wear resistance during abrasive wear is ensured by a structure consisting of metastable residual austenite and martensite. Such a microstructure is created by high-temperature hardening before testing: during operations, austenite on the working surface, as a result of abrasive particles, turns into dispersed and nanocrystalline martensite with a high level of frictional hardening. This also results in the operability of the secondary steel microstructure due to the micro-TRIP effect. An additional means for increasing abrasion resistance is cold treatment after high-temperature hardening, which provides an increase in carbon martensite cooling before testing for wear resistance and the formation of new portions of carbon martensite deformation during testing.

The dependence of the properties of high-carbon roll materials on their chemical composition is investigated. Both cast irons and ledeburite steels were chosen as the research materials. It was shown that the structure and phase composition of the studied materials determine their wear resistance. Alloying indefinite cast iron with molybdenum, vanadium and niobium increases its wear resistance.

A detailed study of microstructure and microhardness distribution at clad-to-substrate interlayer dilution zone as well as elemental profiling were carried out for individual laser clads. Tungsten carbide (44 712-10) and nickel alloy (1560) powders were used for individual clad synthesis at the surface of low alloy steel by coaxial laser cladding technique. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) revealed partial tungsten carbide (WC) melting and secondary chromium carbides formation near WC grains. Iron and nickel elemental profiles were quantified by EDX technique to estimate interlayer dilution zone dimensions. Interlayer zone depth in the clad center increased from 15 to 80 µm when laser power was changed from 0.8 to 1.5 kW while at the outer clad regions it varied in 3–20 µm range. Interlayer clad-to-substrate zone microhardness study revealed a non-uniform dependence of hardness distribution for single clads synthesized with varying laser power.

The structure of retained austenite in wear-resistant steels 150KhNML and Kh12MFL of pearlitic and ledeburitic classes is studied under the conditions of abrasive wear after different variants of heat treatment. The working surfaces of the steels are subjected to electron microscope transmission analysis. It is shown that the retained austenite formed as a result of high-temperature quenching (1100 – 1170°C) is metastable and transforms in the wear process into fine- and nanocrystalline strain martensite with regular periodic arrangement of crystals in addition to slip and twinning. This provides a high capacity of the working surface for friction hardening. The optimum mode of heat treatment for formation of a dissipative structure with high abrasive wear resistance is chosen.

Phase transitions during crystallization and subsequent thermal and deformation effects under the influence of various mechanical loads in welded joints of the plates of medium carbon steel by a consumable electrode in shielding gases with a flux-cored wire based on Fe–C–Cr matrix are studied. The test results for weldability, abrasive wear resistance, and stress state formation and the results of metallographic, electron microscopic, and X-ray diffraction studies are analyzed. It is shown that the structure of welded seam consists of metastable austenite, δ-ferrite, and high-strength carbon–chromium martensite. Welded joints have a high capability of intense hardening under local deformation owing to the TRIP effect (transformation-induced plasticity).

The index of integral solar activity F10.7 is one of the main input parameters of existing ionospheric models, including the model used at early-warning radar stations to compensate for coordinate information errors; the use of external sources of F10.7 seems to be impossible. A method is presented for highly reliable estimate of the solar X-ray flux values at a wavelength of 10.7 cm based only on the capabilities of the station itself.

The quenching heating temperature effect on the amount of retained austenite, the austenite stability from the strain martensitic transformation, as well as the hardening ability and abrasion resistance of high-carbon chromium ledeburite alloys (95Kh18 and 260Kh16M2 cast iron) have been investigated. The γ → α transformation and micro-TRIP-effect on the working surface of the alloys, a dissipative structure with a high degree of friction hardening and good abrasive wear resistance have been formed in this alloys.

The Hochschild cohomology groups for algebras of dihedral type which are contained in the family D(3R) (from the famous K.Erdmann’s classification) are calculated. In the calculation, a construction of the minimal bimodule resolution for algebras from the family under discussion, that is defined in the present paper, is used.

A model of galactic cosmic ray modulation is presented that satisfactorily describes long-period variations in the intensity of the proton and electron components in the waning phase of the solar activity of the 23rd cycle (2006–2009). A distinctive feature of the model is its description of the temporal behavior of energy spectra of both electrons and protons at the same fixed values of model parameters. Model calculations are compared to measurement data obtained on the PAMELA spectrometer for spectra of the proton and electron components of galactic cosmic rays.

The Maksovo shungite-bearing metasapropelite (maksovite) deposit is located in the eastern part of the Onega Basin that was initiated and formed in the Paleoproterozoic in the southeastern Fennoscandian Shield. The maksovite deposit represents a diapiric fold formed about 2050 ± 10 Ma ago. It is underlain by carbonate sequences and, in turn, overlain by tuffaceous siltstones and intruded by gabbro-dolerites (1956 ± 5 Ma). Unaltered maksovites represent pelitomorphic rocks with a massive or obscure-layered structure containing about 30% Corg. Alterations superimposed on the maksovites and underlying tuffaceous siltstone sequences are developed along brecciation zones within the ridge-shaped fold. The alterations are represented by alkaline Fe–Mg metasomatites with brecciated structures, as well as heterogeneous mineral and chemical compositions. They differ in terms of intense biotitization, chloritization, and development of the apatite-bearing albite–carbonate and sulfide-bearing carbonate–quartz stringers. Alteration zones are enriched in Na, K, P, Ti, Mg, Fe, and other ore components. Based on the Re–Os dating of sulfides, the age of metasomatites is estimated at 1558 ± 61 Ma.

Two approaches for improving the resolution via electron probe X-ray spectral microanalysis (EPXRSMA) are considered for the characterization of the nanoparticle composition. The first approach implies the use of L and M series as the analytical ultrasoft X-ray lines of the characteristic radiation of elements to be detected, which are excited by the low-energy electrons (less than 5 keV). The quantitative EPXRSMA, involving a new way for calculating the matrix element correction, is elaborated for this approach. The extrapolation route for the construction of the calibration characteristic is extended to all elements with Z > 40. The second approach is based on the use of the analytical signal caused by only the excitation by electrons of the probe. The achieved lateral resolution is about 2 nm, and the depth resolution is 20–60 nm. The minimal determined mass of the substance is approximately (1–2.5) × 10–21 g, which corresponds to 10–30 atoms of the detected elements.

The frontier of the electron probe X-ray spectral method in the determination of trace metal quantities on a silicon substrate is studied. The experimental data are acquired for ultrathin chromium films on a silicon substrate. It is shown that the signal-to-noise ratio significantly increases at a noticeable sample inclination (80°), which allows one to determine an extremely low (available by this approach) chromium content. The calibration curve for the inclined sample position is plotted using the Monte Carlo method. The surface concentration of chromium atoms (2.2 ± 0.4) × 1014 cm–2 and the chromium detection limit (5 × 1013 cm–2) are measured under the given experimental conditions. For the electron probe X-ray microanalysis of bulk samples, it is a record value. The equivalent weight of chromium at the aforementioned surface concentration is approximately 4 × 10–18 g. The proposed technique requires no changes in the design of the device to be applied.

The satellite ionosondes in highly elliptical orbits are proposed to be used for the task of continuous monitoring of the Arctic ionosphere. The monitoring scheme with the ionosonde location aboard the Arktika-M satellites is presented. The calculations of the vertical topside and transionospheric sounding using the SIMP1 ionospheric model are performed, which show the feasibility of continuous monitoring.

A new structure element of the Arctic ionosphere has been detected from the data of topside sounding of the ionosphere: quasi-vertical walls of high-density plasma. The importance of studying this phenomenon for geophysics and the practice of radio wave propagation in high latitudes is noted. The Arktika-M hydrometeorological space complex with an onboard ionosonde is proposed for its study. The possibility of observing and analyzing all life-cycle phases of this ionospheric inhomogeneity is shown.

The wide application of steel 110G13L for armor plates in mills and crushers makes it urgent to search for alternative materials with close or sufficient operational stability in conditions of shock abrasive wear. A promising path in this direction is the replacement of steel 110G13L with high-carbon pearlitic steels. The aim of this work is a comparative study of the relationship between the structure formed in the heat treatment process of the low-alloyed pearlite steels 70X2GSML and 150HNML and their abrasive wear resistance. Special attention was paid to the possibility of using metastable austenite as a structural component, which increases the abrasive wear resistance of pearlitic steels. It is established that the steel of the pearlite class 70X2GSML, after normalization from 850 °C and tempering at 550 °C, can be used for casting armor plates for ball and rod mills, as well as to cast parts subjected to machining and operating under abrasive conditions without significant impact loads. It is shown that an additional reserve for increasing the abrasive wear resistance of steels of the pearlite class - 70X2GSML and 150XNML - is high-temperature quenching with the formation of a metastable austenite in the structure. The maximum abrasion wear resistance is achieved after the high-temperature quenching of steels (1150 °C) in oil, which forms a martensitic structure with a metastable austenite in the amount of 20-70%, which, with wear, turns into martensite with a high friction hardening ability on the wear surface.

Ways to increase the abrasive wear resistance of high-chromium steel depending on changes in the temperature of heating for quenching and cold treatment are studied in this paper. It was found that during quenching from temperatures of 850-1000 °C, martensite is formed in the structure of steel H12МFL, which provides high hardness: however, maximum abrasion resistance is not achieved in conditions of abrasive wear. An increase in the heating temperature for quenching to 1170 °C leads to a decrease in the initial hardness, which is due to the dissolution of carbides and an increase in the amount of residual austenite, but this is accompanied by a significant increase in wear resistance in abrasive wear. Residual austenite, obtained as a result of high-temperature hardening (from 1170 °C), is metastable and, in the process of wear, becomes a deformation-induced martensite. This gives the steel maximum wear resistance due to its high frictional hardening ability. A further increase in the temperature of heating for quenching above 1170 °C is inexpedient, since it leads to grain growth. Additional possibilities for increasing abrasive wear resistance consist of the cold treatment of high-carbon steels because of an increase in the amount of cooled martensite and an increase in the initial hardness. Cold treatment of the test steel after high-temperature quenching with cooling to minus 70 °C for 20 min and low tempering at a temperature of 200 °C for 2 h allows for further increases to the abrasion resistance by 25% due to the formation of 15% high-carbon chromic martensite cooling and initial hardness up to 60 НRC, with the preservation of 20% of residual metastable austenite and carbides.

A study of the structure and strain-hardening ability relationship was carried out in this work for wear-resistant steels of two structural classes: high-manganese austenitic steel 110G13L and metastable austenitic chromium-manganese steel 60G9KhL. It is shown that the strain-hardening ability can be estimated using a methodologically simple engineering criterion. The criterion determines the metal tendency to harden by determining the Rockwell hardness at the bottom of the indentation cup of the Brinell press indenter

This paper describes the problem of controlling a quadrotor motion in payload transportation on suspension. The suspension is a weightless rod pivotally fixed at the quadrotor mass center with a payload on its end. Equations of motion for a two-dimensional model are obtained using Lagrange equations of the second kind, which serve as a basis for a model revealing the suspension oscillations that destabilize the system. We proposed a controller based on the structural synthesis method and including the deflection angle of the rod from the vertical. The efficiency of the algorithm is confirmed by the simulation results.

A modified method of fuzzy clustering is proposed for determining the aerodynamic characteristics of an aircraft from flight test data. This approach allows one to describe the aerodynamic characteristics of an aircraft in the form of a black box model with inputs in the form of telemetry data, such as accelerations, angular velocities, thrust, and dynamic pressure, and with outputs in the form of dimensionless aerodynamic coefficients of forces and moments. Results of modeling in the MATLAB/Simulink environment are reported.

The structure of models and a description of the AEROSOL-LM/Na module, which is intended for simulating the transport and behavior of impurities sodium coolant and fission product aerosols in a normal operating regime of a reactor and in beyond design basis accidents, are presented. The characteristic features of the module are: accounting for the basic behavior of dissolved impurities in the sodium coolant, simulation of the dynamics of multi-component and polydisperse aerosols in the gas cavity of the first loop of the reactor, functional coupling with other modules of the code (thermal hydraulic and fuel), and simulation of the behavior of fission products as a function of the running state of the reactor installation.

The problem of heat distribution in semiconductor materials irradiated with sharply focused lowenergy electron beams in the absence of heat exchange between the target and external medium is considered by methods of mathematical modeling. The model is based on solving a multidimensional steady-state heatconduction equation using Green’s function. The source function is a model applicable to a wide class of solids and a wide range of energies of primary electrons, based on separate description of the contributions of absorbed and backscattered electrons to the energy dissipated in the target. Using the features of such an approach, a nonmonotonic dependence of the temperature of maximum heating of the target on the energy of primary electrons is explained. The results of calculations using the considered model of heating the target with an electron probe are presented for various semiconductor materials of electronic engineering.

Introduction. The article is devoted to an actual problem of ubiquity of chronic fatigue among qualified sportsmen in the different types of sport and improving the efficiency of monitoring the degree of chronic fatigue, aimed at identifying early signs of chronic fatigue. Purpose. The aim of the article was estimation of psychophysiological state in elite athletes with symptoms of chronic fatigue indiff rantsports. Methods. By using a special computer program q Diagnost 1q held physiological tests to determine latency simple and complex visual-motor reaction, functional mobility, strength and balance nerve processes. Results. The analysis indicates a deterioration of psychophysiological functions in athletes with chronic fatigue. This manifests itself in term sof speed, accuracy and efficiency of information processing. athletes with symptoms of chronic fatigue were detected significantly long latency periods simple and complex visual-motor reactions.This indicates a deterioration in the perception of these athletes visual information,which manifests itself in the reduction of speed, productivity and efficiency of the visual analyzer. Functional motility nerve processes in these athletes wasal so significantly was reduced as compared with athletes without signs of chronic fatigue. Thus indicators of functional motility nerve processes athletes with signs of chronic fatigue ranged low level of functional mobility (90-70 in centives for 1 min). Originality. It is shown that in athletes with symptoms of chronic fatigue was significantly increased latent periods of simple and complex visual-motor response, and decreased functional mobility, strength and balans of nerve processes. Conclusion. Athletes who were engaged in high-speed, speed-strength, powerand playing sports, low levels of functional mobility of nervous processes were detected less frequently than athletes who develop endurance.This is due to the fact that the power,speed and speed-strength,are more related to the functional mobility of nervous processes. The strength of nervous processes primarily associated with endurance and ability to with stand fatigue, maintain for a longtime a high performance of sportsmen.Reducing these indicators in athletes with chronic fatigue can recommened the masone of the main criteria of psychophysiological control of chronic fatigue.

Introduction. The literature data prove the necessity to reorganize the physical education (PE) of female students. This can be expressed, on the one hand, in taking into consideration the menstrual cycle (MC) phases when distributing and orienting physical loads, and on the other hand, in searching for methodological approaches, aimed at improving the body functional state. Incorrect structure of the PE process can negatively affect the functional state of young female athletes and the preservation of their health. Purpose. To study the influence of specially formed dancing health-improving classes on the functional state of female students’ bodies (taking into account the phases of MC) and to evaluate their effectiveness. Methods. 26 female students of the sporting training department were under supervision: two groups of 13 persons – the main group and the control one. They were examined at the beginning and at the end of the academic year. Two exercises were performed. Each lasted for 3 minutes, with a three-minute break. The intensity of the first exercise was selected so that the heart rate did not exceed 120-125 beats per minute, and 140-145 beats per minute for the second one. Besides, pulse and arterial blood pressure were measured in the initial condition before the start of the test, as well as after its completion. On the base of these measurements, the systolic blood volume was calculated according to Starr’s formula. The maximum oxygen consumption (MOC) was calculated according to Karpman’s formula. The mental working capacity was determined by means of the "Landolt Ring" test. The mathematical processing of the obtained data was carried out. Results. The background indicators of heart rate in two groups both at the beginning and at the end of the academic year were within the limits of physiologically normal conditions, the differences in the heart rate indicators of the groups were unreliable. The similar measurements were done after the female students had performed the two stages of exercises. They showed that in the main group the cardiovascular system indicators at the end of the academic year were more favorable. Against the background of a higher PWC170 indicator, they had not so high indicators of systolic and minute volumes of blood, as the control group students had. This proved a more economical functioning of the circulatory system in the process of physical activity. If the MOC at the beginning of the academic year was almost identical and was about 2.3 l/min for both groups, at the end of the second semester, the students of the main group significantly increased MOC, while in the control group it only slightly increased. At the end of the academic year, we recorded a close relationship between the PWC170 and the speed of information processing (r = 0.97) in the postmenstrual period. At the same time, a high correlation with the percentage of correct decisions was kept. In the period of ovulation, the relationship of the PWC170 with the time of test solution and the analysis of one sign remained the same as in the first survey. During the post-ovulatory phase, the dependence between the PWC170 and the speed of information processing increased. During the premenstrual and menstrual phases the stable relationship between the indicators of mental and physical capacity was not found. Conclusion. It has been established that under the influence of annual dancing health-improving classes the female students improved the state of the cardiorespiratory system, increasing the efficiency of its functioning in the course of physical work, which ensured an improved physical efficiency, an increase of work capacity and, most importantly, a significant increase of the maximum oxygen consumption.

The most common type of mechanical wear the machines and aggregates of mining, construction and road industries and transport are exposed to is the abrasive wear. The development of new wear-resistant materials and modes of thermal treatment against this type of wear is one of the most important issues of material science. Wear-resistant materials within various conditions of mechanical wear should have a structure with the metastable austenite developing into disperse austenite while in operation. The paper studies the influence of structural changes on a working surface on the wear resistance of H12ML steel during the process of production, thermal treatment and abrasive wear of parts. It is determined that when quenching from temperatures of 850–1000 °C, the martensite is formed in the structure of high-chromium H12ML steel that ensures high hardness, however, maximum wear resistance is not achieved within the abrasive wear conditions. The rise of heating temperature for the following quenching up to 1170 °C causes the decrease in the initial hardness that is associated with the carbides solution and the increase in the retained austenite quantity; however, it is accompanied by the significant increase of wear resistance during the abrasive wear. The retained austenite produced in the result of high-temperature quenching (from 1170 °C) is metastable and develops into deformation marten-site during wear process; it results in the maximum wear resistance of steel due to the high capacity for frictional hardening of a working surface. Martensite formed on a working surface of H12ML steel during the abrasive wear process has the nanocrystalline structure and periodic distribution.

A semiempirical approach to the a priori evaluation of the effect of the surface relief on the results of X-ray spectral analysis of binary compounds is proposed. Dimensionless parameter k characterizing the effect of the relief on the intensity of intrinsic X-ray radiation is determined using the experimental data obtained for reference monocrystal specimens GaAs with known geometrical parameters of the relief.

This study shows the effect of strain-induced martensitic transformation (austenite (γ)–to–martensite (α′)) on the cavitation erosion resistance of a Fe-Cr-C-Al-Ti deposited layer with a high share of metastable austenite in the structure. For comparison, the cavitation erosion of a E308L-17 deposited layer and an AISI 316L stainless steel substrate was also evaluated. Cavitation tests were performed using a modified ultrasonic tester. X-ray diffraction (XRD) was used to examine martensitic phase transformation. An optical microscope (OM), a scanning electron microscope (SEM), and a 3D optical profilometer were utilized to evaluate the eroded specimens' surfaces. The chemical composition of the Fe-Cr-C-Al-Ti deposited layer was analyzed using an energy-dispersive microanalysis system (EDS). The cavitation results revealed that the Fe-Cr-C-Al-Ti specimen exhibited a resistance to cavitation erosion approximately 4 and 10 times higher than the E308L-17 and AISI 316L specimens, respectively. As shown, effects of γ → α′ transformation were mainly responsible for the results.

The solubility of molybdenum in Fe–Cu and Fe–Sn melts and the growth kinetics of Mo6Fe7 layer at the molybdenum–melt interface at 1200°C are examined. The solubility of molybdenum in these melts is well described by the following equations: lgCMo = (–3.957 ± 0.176) + (25.77 ± 7.94) XFe –– (143.02 ± 77.92) XFe 2 (Fe–Cu melt) and lgCMo = (–2.783 ± 0.011) + (7.563 ± 0.111) XFe –– (10.844 ± 0.245) XFe 2 (Fe–Sn melt). The melt composition (atomic fractions) in the three-phase Mo–Mo6Fe7–melt equilibrium is established: 6.4 · 10–3 Fe, 1.64 · 10–4 Mo, and Cu being the rest (Fe–Cu melt); 0.046 Fe, 3.48 · 10–3 Mo, and Sn being the rest (Fe–Sn melt). The substantial difference between the growth rate constants in the melts, kFe–Sn >> kFe–Cu, at the same iron activity a Fe is attributed to the effect of admixtures (Cu and Sn) on the growth of the Mo6Fe7 layer. Data on the solubility of molybdenum in Fe–Cu and Fe–Sn melts and the growth kinetics of Mo6Fe7 in these melts are obtained for the first time.