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The hysteresis and kinetics of the electro-optic response of multilayer ferroelectric polymer Langmuir–Blodgett films have been investigated.

For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version).ABSTRACT Development of contact networks feeding electrified railways has a trend to use the devices, structures and elements that can be maintained with less efforts and as rarely as possible. The article considers an alternative to application of rollers KS-084 regarding the Russian practices but also suggests approaches and useful tools that can be used on the whole while assessing different operation aspects of power supply systems. Theoretical studies of the permissible normative load on the wire fastening assembly, as well as the experimental verification, including the evaluation of the mechanical strength of GRP rollers for failure in accordance with OST 32.204-2002, showed the complete availability of the composite products offered for operation in the construction of overhead contact systems. Keywords: railway, contact network, catenary, armature, roller, fiberglass, composite, shear, load.

In the present paper, the effect of magnesium nanoparticles implanted in a LiF crystal on the optical properties of color centers is studied. The transmittance spectra and AFM images demonstrate effective formation of the color centers and magnesium nanoparticles in an implanted layer of ∼ 60–100 nm in thickness. Under thermal annealing, a periodical structure is formed on the surface of the crystal and in the implanted layer due to self-organization of the magnesium nanoparticles. Upon excitation by argon laser with a wavelength of 488 nm at 5 K, in a LiF crystal, implanted with magnesium ions as well as in heavily γ-irradiated LiF: Mg crystals, luminescence of the color centers at λmax = 640 nm with a zero-phonon line at 601.5 nm is observed. The interaction of magnesium nanoparticles and luminescing color centers in a layer implanted with magnesium ions has been revealed. It is shown that the luminescence intensity of the implanted layer at a wavelength of 640 nm is by more than two thousand times higher than that of a heavily γ-irradiated LiF: Mg crystal. The broadening of the zero-phonon line at 601.5 nm in the spectrum of the implanted layer indicates the interaction of the emitting quantum system with local field of the surface plasmons of magnesium nanoparticles. The focus of this work is to further optimize the processing parameters in a way to result in luminescence great enhancement of color centers by magnesium nanoparticles in LiF.

We study the Callan–Gross ratio R=dσL/dσT in heavy-quark pair leptoproduction, lN→l′QQ¯X, as a probe of linearly polarized gluons inside unpolarized proton, where dσT (dσL) is the differential cross section of the γ⁎N→QQ¯X process initiated by a transverse (longitudinal) virtual photon. Note first that the maximal value for the quantity R allowed by the photon-gluon fusion with unpolarized gluons is large, about 2. We calculate the contribution of the transverse-momentum dependent gluonic counterpart of the Boer–Mulders function, h1⊥g, describing the linear polarization of gluons inside unpolarized proton. Our analysis shows that the maximum value of the ratio R depends strongly on the gluon polarization; it varies from 0 to Q24m2 depending on h1⊥g. We conclude that the Callan–Gross ratio in heavy-quark pair leptoproduction is predicted to be large and very sensitive to the contribution of linearly polarized gluons. For this reason, future measurements of the longitudinal and transverse components of the charm and bottom production cross sections at the proposed EIC and LHeC colliders seem to be very promising for determination of the linear polarization of gluons inside unpolarized proton.

The form of oxygen-containing inclusions in the LiF crystal was shown to be determined by the laws of isomorphic substitution and impurity accumulation in a melt during crystal growth in open air. Color centers and hydrogen-bonded complexes of different types appear in the LiF crystal after irradiation depending on the form of OH– and Mg2+ inclusions. The radiative decay of OH– ions and the properties of molecular complexes (MCs) with a weak hydrogen bond are responsible for the decreased efficiency of formation of the F- and F2-color centers and increased concentration of the positively charged F 2 + - and F 3 + -centers. Radiochemical reactions involving hydrogen and fluorine atoms and ions that compete with the formation of color centers were presented.

Batch-type spectroscopic and continuous potentiometric titration of K4Mo2Cl8 with potassium dichromate in 1 M hydrochloric acid was carried out. Intermediate forms of molybdenum compounds in the oxidation process were determined. It was shown that the oxidation is accompanied by a rearrangement of the complex structure with the formation of trinuclear oxo- and hydroxohalide anions of molybdenum into trinuclear oxo- and hydroxohalide molybdenum anions. The standard reduction potential of the pair $$\rm{E}^o_{298}(Mo^{VI}/Mo^{IV}_3=1.003+0.032\;V$$ was determined.

The resource of most of the heavily loaded bearing units of agricultural machines in the agro-industrial complex is limited by the quality of the lubricant. To ensure the operating condition of the bearing assemblies, it is necessary to evaluate the tribological characteristics of greases. The paper investigates the lubricity of greases used in agriculture, according to the criterion “scuffing index”. The studies were carried out using standard and original methods for assessing the lubricity of greases. The paper proposes and substantiates a variant of assessing the tribological characteristics of greases based on the “scuffing index” criterion, which consists in determining the wear spot of balls taking into account their plastic deformation zone. It was found that LITOL and LGRT 2 greases have identical antiwear properties.

This paper presents the results of studying the effect of the bias voltage on a copper tube substrate on the texture and residual stresses in 4-layer Ta/W/Ta/W coatings deposited with an inverted magnetron. It is shown that, in contrast to monolayer coatings of Ta and W, in which residual stresses exceeding 2 GPa are formed on the substrate at high voltages on the substrate, stress relaxations occur in the 4-layer coating in alternating layers differing in LTEC values and in the outer W-layer of stress practically absent.

The article presents the results of studies of the effectiveness of the use of the complex probiotic preparation Immunoflor in young hens of egg cross. In the course of the research work, it was found that the use of the probiotic preparation Immunoflor does not affect the clinical and physiological state of the body of young chickens, but at the same time reduces the incidence, mortality and increases the safety of the chickens by enriching and balancing the poultry diet, reducing the conversion feed, optimization of digestion, stimulation of the development of positive microflora in the gastrointestinal tract. The use of the complex probiotic preparation Immunoflor in the diet of young chickens at a dose of 15 g/t of water and 15 g/t of feed contributes to an increase in the number of erythrocytes, leukocytes and hemoglobin concentration, activation of cellular and humoral factors of nonspecific resistance of the body of chickens, providing a normal physiological state and homeostasis.

A hot pressing method is developed for aluminum powder with preliminary sample and die heating to 600°C. The effect of modifying aluminum with carbon nanotubes in an amount of 0.01–1 wt.% is studied. The microstructure, phase composition, and mechanical and electrical properties of the specimens obtained are determined. It is established that the best uniformity and mechanical strength applies to aluminum specimens containing small additions of nanotubes, i.e., 0.01–0.05 wt.%. An increase in carbon nanotube content above 0.1 wt.% is a reason for the occurrence of inhomogeneity formed as a result of nanotube conglomerates.

Boiling curves of distilled water and isopropanol in 12.5x3x0.2 mm microchannel with rigid inlet and outlet lines are obtained. Critical heat flux is calculated for isopropanol by using the previously obtained correlation for water.

In this work, coatings of nanoparticles of aluminum oxide are investigated. Photos were obtained using an electron and optical microscope. A method is proposed for the formation of a coating of nanoparticles with and without agglomerates. The transport properties of nanoparticles of aluminum oxide, silicon carbide, titanium oxide and diamond have been investigated. The effect of agglomerates of nanoparticles on the rise of liquid has been determined.

The existence of thermally induced diffusion of F 2 + centers was shown by measuring the coefficient of optical absorption dichroism of gamma-irradiated LiF crystals. An elementary act of diffusion is a rotation of an F 2 + center with the shift of one of the vacancies in the neighbor lattice site, thus, there is a displacement of the center as a whole. The measured activation energy of rotation is 1.0 eV, which is in a good agreement with the energies of​​ the activation process of F 2 + centers thermal destruction obtained before.

The article examines the issues of determining the value of products of microsystems, both from the standpoint of the integral consumer value, and its internal aspects related to the creation of a methodology for assessing individual components of value. Products microsystems belong to the class of highly reliable products, for which practically existing methods of reliability assessment are not applicable. The article discusses the advantages of creating products of microsystems and proposes an evaluation method that takes into account the factors of structure degradation developed in the process of carrying out lead-free soldered joints of components of radio electronic systems at OJSC Avangard.

The paper presents the results of studies of the resonance structures of the background electromagnetic noise spectrum obtained in a series of experiments in the autumn of 2012 in Karelia. The experiments are unique because the background noise was detected at stations spaced by a distance much less than the doubled effective waveguide height (about 50 km) in a region close to the main ionospheric trough, the structure and position of which were determined based on radiotomographic data. It is shown that the dimensions of the ionospheric local region, which affects both the generation of spectral resonance structures in particular and the propagation of electromagnetic waves in the considered range in general, depend significantly on the variation of ionospheric parameters in regions with strong horizontal inhomogeneity.

We present the QCD predictions for the azimuthal $\cos 2\varphi$ asymmetry in charm leptoproduction for the kinematics of the COMPASS experiment at CERN. The asymmetry is predicted to be large, about 15%. The radiative corrections to the QCD predictions for the $\cos 2\varphi$ distribution are estimated to be small, less than 10%. Our calculations show that the azimuthal asymmetry in charm production is well defined in pQCD: it is stable both perturbatively and parametrically, and practically insensitive to theoretical uncertainties in the input parameters. We analyze the nonperturbative contributions to the $\cos 2\varphi$ distribution due to the gluon transverse motion in the target and the $c$-quark fragmentation. Because of the $c$-quark low mass, the nonperturbative contributions are expected to be sizable, about (30--40)%. We conclude that extraction of the azimuthal asymmetries from available COMPASS data will provide valuable information about the transverse momentum dependent distribution of the gluon in the proton and the $c$-quark hadronization mechanism. Finally, we discuss the $\cos 2\varphi$ asymmetry as a probe of the gluonic analogue of the Boer-Mulders function, $h_{1}^{\perp g}$, describing the linear polarization of gluons inside unpolarized proton., Comment: 9 pages, 4 figures, LaTeX, journal version

The characteristic energy of distributions of Ag and Cu nanoclusters in LiF-based thin films is estimated from the slope of the I–V characteristic, built in double logarithmic coordinates logI = f (logU). It is shown that the energy states of small clusters lie above the bottom of the conduction band and form a potential barrier, while the energy states of large clusters lie below the bottom of the conduction band and form a potential well. The change in the positions of energy levels along with nanocluster size and the effect of quantum limitations imposed on the electrical and optical properties of the system are confirmed experimentally.

Proton-conducting membranes have been obtained by sol–gel synthesis involving tetraethyl orthosilicate and sulfonated suspension copolymers of styrene with allyl glycidyl ether. The membranes are gels consisting of a polymer matrix, in which silica particles are uniformly distributed. The synthesized membranes are characterized by the proton conductivity of up to 4.21 × 10–2 S/cm at 343 K and 75% humidity, an ion exchange capacity of 3.5 meq/g, a proton-transfer activation energy of 25.2 ± 2.6 kJ/mol, thermal stability of up to 130°C, and mechanical strength (tensile modulus of elasticity, 322 MPa).

The effect of impurities on the efficiency of the formation of color centers and hydrogen-bonded molecular complexes upon exposure to various radiations in lithium fluoride crystals grown in air is studied. The results of experiments for measuring optical properties, IR vibrational spectra, luminescence, and thermally stimulated luminescence are presented. The fact that the band in the range of 1800–2300 cm–1 corresponds to stretching vibrations of a complex with strong hydrogen bond is proved based on the Fermi-resonance perturbation in the region of 2080 cm–1, shaped as the Evans hole and bands A, B, and C. It is shown that the composition of these complexes includes an OH– ion and an HF molecule. The crucial role of O2‒ V + oxygen dipoles in the aggregation efficiency and gradient distribution of color centers and radiation resistance of hydroxyl ions is revealed. It is shown that products of radiation decomposition of OH– ions stimulate, while decay of O2‒ V + dipoles suppress, the formation of positively charged color centers.

This paper presents the results of experimental studies on the formation conditions of a highly directional supercontinuum (SC) produced via filamentation of a femtosecond laser pulse in air. The laser beam had an energy of 8–15 mJ, radiation wavelength of 940 nm and pulse duration of 70 fs. A spherical mirror, with or without aberrations, was used to focus the laser beam. It is shown that a SC forms behind a visible filament through a step-by-step conversion of the spectral composition from long wavelength to short wavelength (to 350 nm). The radiation is most stable when it is generated in the presence of aberrations in the wave front of the laser beam. On the track section 35–135 cm from the filament, radiation propagates in the form of a spatially stable structure similar to a soliton with a transverse dimension ≤300 µm. In this case, the SC significantly differs from the conical off-axis emission that occurs in the aberration-free filament, in that it displays a divergence close to the diffraction limit, linear polarisation and a shorter-range wing of the spectrum. The infrared component of the SC has a duration 2.8-times shorter than the pulse duration of the initial laser beam.

The occurrence of single-event upsets (SEUs) in 90-nm SRAM integrated circuits irradiated by 1000-MeV protons has been investigated. The experimental data were analyzed and processed, and the results showed the possibility of multiple cell upsets in the integrated circuits studied.

The distribution of pixels with high-value dark current in CMOS image sensors irradiated by protons with the energy of 1000 MeV and neutrons with a continuous spectrum simulating the energy spectrum of atmospheric neutrons is explored. Data on generation of spike clusters in the irradiated sensors and the exposure time influence on the cluster parameters are obtained.

We consider the azimuthal $\cos \varphi$ and $\cos 2\varphi$ distributions and the Callan-Gross ratio $R={\rm d}\sigma_L/{\rm d}\sigma_T$ in heavy-quark pair electroproduction, $lN\rightarrow l^{\prime}Q\bar{Q}X$, as probes of linearly polarized gluons in unpolarized nucleons. Our analysis shows that the azimuthal asymmetries and Callan-Gross ratio are predicted to be large and very sensitive to the contribution of the gluonic counterpart of the Boer-Mulders function, $h_{1}^{\perp g}$, describing the linear polarization of gluons inside unpolarized nucleon. In particular, the maximum values of the azimuthal distributions vary from 0 to 1 depending on $h_{1}^{\perp g}$. We conclude that future measurements of these quantities at the proposed EIC and LHeC colliders could clarify in details the proton spin decomposition puzzle., Comment: 4 pages, 4 figures, talk given at the XVIII Workshop on High Energy Spin Physics (DSPIN-19), September 2-6, Dubna

The uncontrolled energizing of shunt reactors is accompanied by appearance of a significant DC-component in current, leading to saturation of power and instrument transformers in adjacent network [1], [2]. DC-component causes high inrush current that have an electrodynamic impact on power network equipment [3]. In order to prevent these negative consequences, controlled switching devices providing reactor optimal energizing instant are used.

The faults in AC network may cause commutation failure in adjacent inverter station of HVDC, accompanied by injection of DC line discharge current into AC network. In this case a significant number of transient components arises in emergency voltages and currents, which level is comparable with level of main harmonic. Conventional protection relays may miss-operate due to error in non-adaptive orthogonal component filters during processing of such signals. The implementation of adaptive signal processing algorithms for improving relay protection stability is studied. It's shown that improving of signal recognition require proper sampling rate and adaptive signal model order. An adaptive blocking algorithm preventing protection miss-operation in poor measurement conditions is suggested.

The problem of radio imaging small aircrafts in radio systems with inverse aperture synthesis is considered. The problem is reduced to solving undetermined system of linear equations to be solved by regularization in Holder space l q . The results of numerical simulation are presented.

Results of calculations and analysis of the tearing-mode evolution under the effect of resonant magnetic perturbation produced by a nonlinear feedback system in rotating tokamak plasma are presented. The TEAR-code used for calculations is based on the visco-resistive magnetohydrodynamic approximation that gives coupled diffusion-type equations for the magnetic flux perturbation and for the plasma rotation velocities in toroidal and poloidal directions. The code is supplemented by a computational unit simulating the nonlinear algorithm of the feedback system. The feedback gain and phase shift are automatically regulated in real time. The gain depends on the tearing-mode amplitude. At high feedback input signals, the gain does not exceed some finite value to reduce technical requirements for the feedback actuator and to mitigate the phase instability. In the process of the tearing-mode suppression, the gain gradually increases to provide the mode control under reduction of feedback input signal and rise of the intrinsic tearing-mode stability index. Besides that, the real-time control of the feedback phase shift is provided to additionally mitigate the phase instability. According to simulation, the used nonlinear characteristics of the feedback algorithm improve the efficiency of the tearing-mode suppression.

The article presents the results of a study focused on the awareness of the fact that specialists with digital literacy are in demand in rural areas of Yakutia. The authors justify the need for the use of digital technologies in agriculture, analyzing the opinions of individual specialists.

A universal center for testing electronic components (ECs) for the needs of aviation and space is created in the SC-1000 Petersburg Nuclear Physics Institute, National Research Centre “Kurchatov Institute” (PNPI NRC KI). One of the main instruments of these tests is variable energy protons beams. This paper presents Monte Carlo simulation results for a proton beam with energy of 1000 MeV passing through copper and tungsten degraders, and defines the length of these degraders to obtain energies of ~60, 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000 MeV. Detailed studies of further transmission of the proton beams along the beam line using the copper degrader are accomplished. Basic theoretical parameters for each proton beam, such as the intensity, the energy heterogeneity, beam size, and uniformity of its spatial distribution are obtained.

Objective. We investigated homocysteine metabolism in men with early stages of chronic kidney disease (CKD) and metabolic syndrome (MS). Design and methods. A total of 79 men were selected and divided into two groups, i. e. CKD C1–C2 degree and MS with abnormal carbohydrate metabolism (main group, n = 44) and CKD C1‑C2 degree and MS with normal carbohydrate metabolism (control group, n = 35). We assessed serum levels of fasting and postprandial glucose, HbA1c, insulin, C‑peptide, homocysteine. We also studied polymorphisms of the genes encoding homocysteine metabolism-related enzymes. Results. 82,3% patients had elevated serum levels of homocysteine with no significant differences between the groups. 90,0% cases of hyperhomocysteinemia (HHC) in men with CKD C1–C2 degree and MS were associated with polymorphism of the genes encoding homocysteine metabolism-related enzymes. In men with CKD C1–C2 degree and MS with normal carbohydrate metabolism we found positive correlations between creatinine and homocysteine (rs = 0,4; p < 0,05). Conclusions. The majority of men with MS and CKD C1–C2 degree have hyperhomocysteinemia that is usually determined by genetic factors. Serum level of homocysteine at the initial stages of renal dysfunction does not depend on the state of carbohydrate metabolism in MS.

Experimental results are used to justify the method of determination of the quality of resistance welding of samples of interconnections of lead-acid batteries using torsion tests. The orig...

Evidence for the formation of molecular complexes with strong hydrogen bond with fluorine in lithium fluoride crystals containing impurities of OH ions and magnesium under the action of irradiation are presented. The proofs are based on Fermi resonance perturbation of IR stretching vibration bands in the region of 1800–2300 cm −1 . It is established for the first time that the profile of the stretching vibration bands has three types of perturbations owing to Fermi resonance of stretching vibrations with its overtones: (1) the effect on the band profile without perturbation; (2) “Evans hole” at 2080 cm −1 ; (3) A, B, C bands. Manifestation of these particularities depends on a dose and conditions of a crystal irradiation. It is shown that the IR spectra recorded at a helium temperature confirm that the centers with bands at 1800–2300 cm −1 belong to the complexes with hydrogen bond. It is proposed that the OH ion, HF molecule and fluorine ion to be considered as the main structural units of the complex.

Results are given for comprehensive research concerning fields of metallurgy, nanomaterials, and ecology. Taking account of theoretical concepts and known practice of modifying gray cast iron, a new ultrafine modifier is considered containing carbon with increased chemical activity. It is established that carbon foam, electrolyzer dust from electric filters, and alumina passing through a dry gas cleaning system, have carbon nanostructures in their composition. Raw material composition for preparing modifying additive, procedures, and experimental materials are provided. Results are given from a series of cast iron melts with a different modifier content and a method for adding it with replacement of 50% of standard metallurgical graphite by the carbon-containing part of carbon foam. The effect of modifier on phase formation during gray cast iron solidification by means of cooling from a liquid condition is considered. A test cast iron sample and reference cast iron are analyzed chemically, and mechanical properties are analyzed. It is established that a modifier makes it possible to improve gray cast iron grade. Theories are proposed for carbon nanotube formation during aluminum production. A technology is provided for extracting carbon structures from starting raw material. It is shown that with preparation of one ton of aluminum using the production solutions developed for decontamination and utilization of industrial waste it is possible to produce modifier based on highly organized carbon nanostructures.

Adaptive methods for signal detection and direction finding are considered in the framework of the maximum likelihood method. The possibility of application of adaptive methods for solution of the problem of coherent passive radar is shown.

The microstructure of lithium fluoride thin films deposited on a glass substrate by thermal vacuum evaporation was investigated. An additional annealing of the films in air at temperatures of 400, 500, and 600°C resulted in an increase in the size of grains forming the film, as well as in the transformation of luminescence spectra of the initial and annealed samples before and after their X-ray irradiation used to generate in the films color centers that played the role of luminescent probes. It was found that an increase in the annealing temperature with an increase in the size of grains leads to a decrease in the intensity of the characteristic photoluminescence bands of color centers in lithium fluoride and to the appearance of new luminescence bands that are not characteristic of this material. Based on the results of the X-ray powder diffraction analysis, it was concluded that the increase in the grain size is caused by the change in the chemical composition of the films primarily due to the interaction of lithium fluoride with the substrate material.

Results of the experimental study of population inversion in the resonant electronic transition \({B^3}{\pi _g} - {A^3}\sum _u^ + \) of nitrogen ions by optical pumping of atmospheric air and pure nitrogen by a femtosecond laser pulse at a wavelength of 950 nm are presented. It is shown that the inversion results from selective population of the \(N_2^ + \left( {{B^2}\sum _u^ + ,v' = 0} \right)\) excited state during multiphoton excitation of the autoionization state of the nitrogen molecule with an energy of 18.7 eV. Seed photons for superradiance at transitions of molecular nitrogen ions are photons of the axial supercontinuum that occurs in a filament at the corresponding wavelengths. The superradiance mode is implemented at the wavelength λ = 358.4 nm referred to the transition of the CN molecule.

The results of investigation on high-temperature gas-phase removal of impurities from a granulated quartz concentrate are presented. Various gaseous media and treatment methods are considered. The influence of the main process parameters on the impurities content in raw quartz are estimated and the optimal values are selected.

Compression isotherms and chemical compositions of stearic acid (HSt) monolayers applied onto an aqueous subphase containing cadmium ions have been studied in a wide pH range. The data obtained have been used to calculate the dependences of surface elasticity E 2.5, change ΔA 2.5 in the surface area per molecule at a constant two-dimensional pressure in the monolayer of 2.5 mN/m, and change Δ|ζ| in the absolute value of the ζ potential of particles formed from the material of a monolayer collapsed on the surfaces of aqueous solutions with the same compositions on the pH of the subphase. The obtained data are in good agreement with each other and unambiguously attest to the dependences of the surface (E 2.5, ΔA 2.5) and electrosurface (Δ|ζ|) characteristics of the monolayers on their chemical composition. This leads us to make the reasonable suggestion that two alternative reactions may occur between cadmium ions and the HSt monolayer with the formation of two salts, CdSt2 and Cd(OH)St.

The paper investigates the textural characteristics of carbon sorbents obtained from Kuzbass coal of the LF grade. The sorbents were obtained by activation using ferric chloride, pre-impregnating the coal with an iron III chloride solution at a FeCl3/coal ratio of 1:7 g/g. Powder X-ray diffraction in sorbents proved the presence of the Fe3O4 phase of magnetite. The amount of magnetite in the sorbents varies within 7%. It is shown that sorbents obtained from coal activated with iron chloride have a sufficiently developed porous structure and significant microporosity. The measured values of the specific surface area of sorbents at an activation temperature of 800 °C reach 250 m2/g, and at 700 °C they are an order of magnitude lower. The total pore volume does not exceed 0.1 cm3/g with a micropore fraction of more than 70%.

(Jury. R. General. Protection. Nar. Health. 1897, April, No. 4, p. 276).

Basic oils produced from oil or obtained by the synthesis of monomers are generally chemically neutral. To improve the service properties of base motor oils, additive packages and active ingredients are introduced into it. The presence of anti-seize, anti-wear, and dispersing-stabilizing additives in a composition of commercial oil of a certain concentration of compounds of alkali metal salts changes its chemical activity [1]. Based on this, as a measure of service properties (anti-seize, anti-wear and dispersion-stabilizing properties (DSP)) of commercial motor oils can be used hydrogen indicator - pH. In the work, as an invariant estimate of the concentration of resource additives and service properties of commercial motor oils, the use of pH is considered. Correlation dependences of pH on BSP and viscosity of the studied motor oil are given.

The failure-free performance of the components determines the technical and economic efficiency of the use of the combine harvester. A low level of reliability leads to an increase in the cost of harvesting, the need for unscheduled repairs due to failures of parts, assemblies and assembly units. Studies have shown that a significant proportion of failures occur in power transmission units. In this regard, the aim of the work is to assess the reliability of the power transmission of the John Deere 9660 combine harvester. The average time between failures of the power transmission units was 80 hours, which does not meet the regulatory requirements (according to STO AIST 8.22 - 2010 - at least 100 hours). Failures of all powertrain assemblies are caused by a combination of failures: wear and fatigue failure of the bore holes for the bearings of the unit housings, and gears, bearings from dynamic loads.

In this paper, we consider the use of the polarization-optical method for assessing the stress-strain state of films of polymeric material in the restored tribomechanical system “bearing ring - housing” and the dependences for determining the magnitude of the principal stresses are proposed. When studying the stress-strain state, compounds with a diameter of the contact surface of 40 mm from an optically sensitive material imitating an adhesive layer were used as models. The photoelasticity method showed that the maximum stresses occurred on the axis of symmetry of the model, and the contact arc was 180 degrees. A qualitative picture of the strips indicates the identity of the stress-strain state of the adhesive joint model both for the uniform gap model and for the eccentricity models.

Heat transfer crisis was investigated during water boiling in a microchannel without coating and with coating of aluminum oxide nanoparticles. Experiments were performed on an advanced setup with a horizontally located microchannel with dimensions of 12.5x3x0.2 mm. Calculation of the critical heat flux in the microchannel without coating and with a coating from nanoparticles, carried out by formulas for heat transfer crisis in a horizontal pipe with microporous coating and one-sided heating. For the microchannel coated with nanoparticles the critical heat flux was calculated for the conditions of no influence of liquid subcooling and initial section. The satisfactory agreement between the experimental and calculated data was obtained. dependences of the critical heat flux from the coating thickness and characteristic size of particles were also shown. However, the data array is limited and needs to be expanded what will improve the equations for critical heat flux in a microchannel with nanoparticles coating.