bluuebunny/crossref_metadata_2025 huggingface dataset:
CORROSION BEHAVIOR OF 12Cr18Ni10Ti STEEL IN LiCl–KCl MELT CONTAINING ADDITIVES OF f-ELEMENT CHLORIDES
Authors: Karfidov E. A. , Nikitina E. V. , Seliverstov K. E. , Mushnikov P. N. , Karimov K. R.
Published: April 2024

When reprocessing spent nuclear fuel, it is supposed to use LiCl–KCl melt (0.49:0.51) in an inert atmosphere, all metal materials in this salt melt are extremely susceptible to corrosion, besides, during the processing of spent fuel, both the liquid (melt) and the gas phase are saturated with decay products that can act as additional oxidizing agents, increasing the aggressiveness of the environment. The pyrochemical technology of SNF includes operations such as soft chlorination, electrofining and metallization, implying the presence in the melt of compounds of chlorides of rare earth metals lanthanum, cerium and neodymium, as well as uranium(III, IV) chlorides. In this work, the corrosion behavior of 12CR18NI10TI steel in LiCl–KCl melt containing NdCl3, CeCl3, LaCl3, UCl3 and UCl4 additives up to 2 wt % was investigated. Corrosion tests lasting 100 hours were performed at a temperature of 500°C in an inert argon atmosphere. It was found that the presence of REM chlorides significantly reduces the degradation of the steel under study. The addition of (REM)Cl3 leads to the formation of a compound (REM) on the surface of the samples OCl, the thickness and continuity of which increases in the following row: LaCl3 NdCl3 CeCl3. The formation of such a compound leads to the inhibition of the corrosion process of steel 12CR18NI10TI due to salt passivation of the surface. The addition of UF4 to the melt causes significant corrosion of 12CR18NI10TI intercrystalline steel. The introduction of UF3 into the melt leads to a decrease in the corrosion rate, which is associated with the predominant interaction of trivalent uranium chloride with dissolved molecular oxygen contained in the melt, and the formation of a non-stoichiometric compound with the crystal chemical formula U3O7 on the surface of samples according to microrentgenospectral analysis.
MULTICOMPONENT ALLOYS AND LAYERED COMPOSITE NANOMATERIALS FOR HYDROGEN TECHNOLOGIES
Authors: Polukhin V. A. , Estemirova S. H. , Kurbanova E. D.
Published: April 2024

The stability of high entropy alloys (HEA) is of great importance for various applications in many areas. This review covers one of the most topical areas in this area – the creation of stable multicomponent membrane alloys with improved performance. The review presents an analysis of the results of studies of equiatomic and non-equiatomic four- and five-component alloys, which are successfully used as membrane alloys for hydrogen technologies. An effective method for increasing the strength of membrane alloys is a special heat treatment, as a result of which secondary strengthening phases are precipitated and superlattices are formed. In addition, an unusual morphology of micrograins is formed in the form of cuboid blocks with rounded tops, spheroidal and ellipsoidal grains, consisting of hardening thermodynamically stable γ' and γ-phases isolated during heat treatment. Alloying is an important factor in strengthening HEAs. The influence of alloying with Ni or Cr on the mechanical properties of a number of multicomponent compositions has been analyzed. It is shown that Al + Ti or Al + Nb alloying pairs, structured into matrices of solid solutions of membrane alloys, increase their strength, thermal stability, hydrogen kinetics, and resistance to hydrogen embrittlement. Within the framework of molecular dynamics, the effect of strain hardening of membrane HEAs by multiple deformation has been studied and the mechanism for creating a synergistic effect has been established. The review also presents relatively recently obtained hexa- and pentagonal two-dimensional structures with ultrahigh strength and increased thermal stability and excellent photocatalytic properties, such as MX2 dichalcogenides and their pentagonal configurations, as well as two-dimensional alloys Cu1 – xNix, Ti1 – xNix and compounds Bi1 – xSbx. All these materials are effective catalysts for water dissociation and hydrogen concentration. Particular attention is paid to neural network prediction of interatomic potentials as an effective method of theoretical research for the search for new membrane HEAs.
SYNTHESIS OF LEAD TUNGSTATE IN MELTS OF THE SYSTEM (Li2WO4–Na2WO4)evt–PbSO4
Authors: Cherkesov Z. A. , Kushkhov Kh. B. , Kyarov A. A.
Published: April 2024

The structure of the crystallization surface of the system (Li, Na), Pb // SO4, WO4 has been studied in a wide concentration and temperature range in order to identify compositions with optimal physicochemical parameters that can be used as the basis for the synthesis of highly dispersed lead tungstate with high yield and purity. The system (Li2WO4–Na2WO4)evt–PbSO4, which is a diagonal section of the system (Li, Na), Pb // SO4, WO4, was chosen as a working system for solving the task set in the work. For the first time, the concept of a “complex component” is used in the work, which is a mixture of lithium and sodium tungstates, as well as lithium and sodium sulfates at the vertices of the square of compositions. The complex components are eutectic compositions of the corresponding lithium tungstates, sodium and their sulfates. This approach to the study of the “resulting” triple mutual system (Li, Na), Pb // SO4, WO4 on the vertices of which complex components are located allowed us to take advantage of the noticeable differences between the studied system and the original triple mutual systems Li, Pb // SO4, WO4 and Na, Pb // SO4, WO4. It is shown that the studied system (Li, Na), Pb // SO4, WO4 has a number of advantages both in terms of melting temperatures of the eutectic mixture on the side of Li2,Na2(WO4)2–Li2,Na2(SO4)2, and in terms of the shift of the line of joint crystallization of phases, which leads to a noticeable increase in the crystallization surface lead tungstate. In this regard, before proceeding to the production of lead tungstate, we estimated the thermodynamic probability of the reaction underlying the synthesis of lead tungstate on the basis of the Temkin-Schwarzman method and the Van’t-Hoff isotherm equation of chemical reactions. Calculations have shown that all metabolic processes proceed with high negative Gibbs energies. The obtained samples of lead tungstate were analyzed by the X-ray phase analysis method on the X-ray diffractometer Dron-6, and their dispersion was determined on the Fritsch Analysette 22 Nanotek Plus laser particle analyzer. The presented results of a theoretical analysis of the possibility of implementing a method for synthesizing lead tungstate in melts of the (Li2WO4–Na2WO4)evt–PbSO4 system and experimental material for its implementation can become the basis for the development of technology for obtaining highly dispersed lead tungstate powders.
X-RAY PHOTOELECTRON SPECTROSCOPY STUDY OF THE REDUCTION AND ADSORPTION CAPACITY OF CARBON NANOMATERIALS BY THE RELEASE OF Mn(VII) IONS
Authors: Dorogova V. A. , Yolshina L. A. , Pryakhina V. I.
Published: April 2024

The reductive and adsorption capacity of hierarchically structured carbon films synthesized from glucose on a molten aluminum catalyst under a layer of molten salts and thermally reduced graphene oxide upon their interaction with a sodium permanganate solution in a neutral medium at room temperature has been studied. The data obtained by X-ray photoelectron spectroscopy show that all manganese adsorbed on the surface of all carbon nanomaterials is in a reduced form – most of it is in the form of quadrivalent manganese ions, and about 20% is in the form of trivalent manganese ions, which makes the formed carbon-oxide composites promising materials as cathodes of chemical current sources. Thermally reduced graphene oxide demonstrated the lowest adsorption activity. Hierarchically structured carbon films make it possible to adsorb up to 100 wt % of the original manganese in neutral media, which is much higher than with all known commercial adsorbents.
EFFECT OF THE SUBSTRATE MATERIAL ON THE KINETICS OF SILICON ELECTROREDUCTION IN THE KCl–CsCl–K2SiF6 MELT
Authors: Gevel T. A. , Gorshkov L. V. , Suzdaltsev A. V. , Zaikov Yu. P.
Published: April 2024

Due to the possibility of controlling composition and morphology, one of the promising methods for obtaining silicon and its materials is the electrolysis of molten salts. However, this requires data on the influence of various factors on the kinetics of silicon electrodeposition. In this work, an effect of the cathode substrate material on the kinetics of electroreduction of silicon ions in a low-fluoride melt (wt %) 57KCl–43CsCl with the addition of 2.8 wt % K2SiF6 at a temperature of 730°C was studied by cyclic voltammetry and chronoamperometry. Interacting and indifferent materials for silicon were chosen as substrates: glassy carbon, silver, and nickel. On the glassy carbon electrode, the electroreduction of silicon ions proceeds in the potential region more negative than –0.05 V, on the silver electrode, more negative than 0.05 V, and on the nickel electrode, more negative than 0.40 V relative to the potential of the silicon quasi-reference electrode. For all the studied substrates, a cathode process is observed, which is not electrochemically reversible. In this case, according to chronoamperometry measurements, the stage of nucleation of a new phase at the cathode does not affect the kinetics of the process under study. Presumably, in the case of glassy carbon and silver, irreversibility can be caused by a delayed discharge, while silicon electrodeposition on a nickel electrode is accompanied by the formation of nickel silicides. From the voltammetric and chronoamperometric dependences, the diffusion coefficient of silicon ions to the glassy carbon electrode was estimated, the values of which were 1.5 · 10–5 and 1.2 · 10–5 cm2/s, respectively.
MATHEMATICAL MODEL OF CRYSTALLIZATION OF UO2–ZrO2 CATHODE DEPOSIT WITH SIMULTANEOUS ELECTROCHEMICAL AND CHEMICAL REACTIONS ON THE ELECTRODE
Authors: Krotov V. E. , Filatov E. S.
Published: April 2024

A mathematical model is presented for the electrolytic synthesis of a crystalline cathode deposit UO2–ZrO2 with simultaneous and continuous electrochemical and chemical reactions occurring on the electrode. Uranium dioxide is formed by an electrochemical reaction during the reduction of uranyl ions \({\text{UO}}_{2}^{{2 + }}{\text{,}}\) zirconium is emerges by a chemical exchange reaction. Using the Faraday and Fick’s equations, an expression was obtained for calculating the content of zirconium dioxide in the UO2–ZrO2 system, which adequately describes the process of its synthesis in the NaCl–KCl–UO2Cl2–ZrCl4 melt. Qualitative coincidence of the geometric shape of the dependences, and, in some cases, quantitative correspondence of the calculated and experimental values of the zirconium dioxide concentration on the process conditions (ZrCl4 concentration, current density and duration of electrolysis, temperature) was established. The discrepancy between the values is explained by the volatilization of a part of ZrCl4 from the electrolyte during electrolysis, which was not taken into account when deriving the analytical equation.
PROTECTIVE METAL COATINGS MADE OF MOLYBDENUM ON STEEL 12Cr18Ni10Ti FOR FLUORIDE MELTS. OBTAINING, CERTIFICATION, EFFICIENCY
Authors: Nikitina E. V. , Kuznetsova A. V. , Seliverstov K. E.
Published: April 2024

The successful use of molten alkali metal fluorides as an electrolyte for high-temperature devices requires the development of such reactor materials that have high corrosion resistance in melts with compositions characteristic of liquid-salt mixing reactors. This is one of the most important unresolved problems. One of the effective ways to reduce corrosion losses is to create a layer on the surface of the material that protects the metal from the corrosive effects of the environment. In this paper, molybdenum insulating coatings on steel 12Kh18Ni10Ti obtained in molten salts of various compositions and by various methods are considered as protective layers. Experiments were carried out on the electrodeposition of molybdenum coatings on structural materials based on iron (steel 12Cr18Ni10Ti). The coatings obtained by the electrochemical method are inhomogeneous and easily exfoliating. The thickness of molybdenum coatings obtained from molten salts is 8.15 and 20.34 μm on steel in FLiNaK and LiCl–KCl melt, respectively. Corrosion tests have shown the inefficiency of the molybdenum coating obtained from both chloride and fluoride melts. The corrosion rate of 12Cr18Ni10Ti steel in FLiNaK/FLiNaK + 5% CeF3 melts at 650°C and a holding time of 100 hours decreases in the following row: 12Cr18Ni10Ti + Mo (0.75/0.77 mm/year) 12Cr18Ni10Ti (0.45/0.50 mm/year).
PREDICTION OF THE THERMOPHYSICAL BEHAVIOR OF AMORPHOUS OF ALLOYS Ni0.333Zr0.667 AND La80Al20 ACCORDING TO PROPERTIES OF METALS
Authors: Terekhov S. V.
Published: April 2024

Amorphous alloys (metallic glasses) are obtained by ultrafast cooling of melts. As a result of this process, the chaotic distribution of atoms in space is “frozen” while maintaining the short-range order characteristic of liquids. The high homogeneity of the solid state leads to unique mechanical, magnetic and other physical properties. This has led to the fact that cheaper metallic glasses have replaced a number of traditional materials in some industries. On the other hand, significant disadvantages of disordered media are temperature and time instabilities. The solution to this problem is possible with knowledge of the thermophysical properties of amorphous alloys: heat capacity, thermal expansion coefficient, thermal conductivity and thermal diffusivity. Even estimating, for example, their temperature dependences is a complex and urgent task. Therefore, in this paper, it is proposed to use the mixing rule for components whose thermophysical properties are known. This makes it possible to predict the temperature dependences of heat capacity, thermal expansion coefficient and thermal diffusivity at known values of thermal conductivity for different temperatures. Note that the obtained curves for the Ni0.333Zr0.667 and La80Al20 amorphous alloys are in good agreement with the experimental data.
ELECTROREDUCTION OF NICKEL(II) CHLORIDE, COBALT(II) FLUORIDE AND MOLYBDENUM(VI) OXIDE MIXTURES IN A HEAT ACTIVATED BATTERY
Authors: Volkova O. V. , Zakharov V. V. , Pershina S. V. , Antonov B. D. , Pankratov A. A.
Published: April 2024

The discharge characteristics of the elements of a thermally activated chemical current source (HAB) containing NiCl2–CoF2–MoO3 mixtures as a positive electrode are investigated. It is established that molybdenum oxide stabilizes the discharge plateau and increases the discharge voltage at temperatures above 530°C. The discharge curve has a stepwise character. The number of steps of the discharge curve is determined by the operating conditions of HAB. The low-voltage stage (less than 0.4 V) corresponds to the reduction of lithium molybdates, which are formed by the interaction of molybdenum oxide with the reduction products of transition metal halides. A study of the cathode reduction products by the methods of XRD, STA and SEM was carried out. It is established that during the discharge of the HAB element, the initial components of the cathode mixture are restored to metals that form a dendritic matrix. The DSC curves of the salt fraction formed during electrochemical reactions have a number of thermal effects corresponding to the temperatures of joint melting of a triple mixture of lithium halides LiF–LiCl–LiBr and eutectic dual systems LiF–LiCl, LiCl–Li2O, in which transition metal halides and lithium molybdates are dissolved.
EFFECTIVE VISCOSITY AND GLASS TRANSITION TEMPERATURE OF Cs2O–B2O3 MELTS
Authors: Khokhryakov A. A. , Samoilova M. A. , Ryabov V. V. , Vedmid’ L. B.
Published: April 2024

Effective viscosity (viscoelasticity) of cesium and boron oxides melts was measured at temperatures 900–1600 K and concentrations 0 ≤ x ≤16 mol % Cs2O by vibration viscosimetry. It was shown that vibration leads to non-Newtonian flow of melts. This means that not only configuration activation energy, the switching energy of bridging oxygen bonds but also the elastic energy of structural units of melts associated with activation energy of viscous flow. Using parameters under conditions of Newtonian and non-Newtonian flow of melts, shear viscosity η', elastic modulus G' and stored viscosity η'' were calculated. It was shown that cesium boron melts in conditions of high shear rates can be considered as liquids with viscous and elastic properties. Glass transition temperature (Tg, K) was measured by DSC, its dependence of content of cesium oxide was plotted and explained.
INVESTIGATION OF THE MECHANISM OF LANTHANUM IONS ELECTROREDUCTION ON NICKEL ELECTRODE IN CHLORIDE MELT
Authors: Kushkhov Kh. B. , Kisheva F. A. , Vindizheva M. K. , Mukozheva R. A. , Kozhemova K. R. , Beroeva L. M.
Published: April 2024

The electrochemical behavior of lanthanum ions on a nickel electrode has been studied using various electrochemical methods such as cyclic voltammetry, chronopotentiometry, open circuit chronopotentiometry (on-off curves), and square wave voltammetry in an equimolar melt of potassium and sodium chlorides at 973 K. The cyclic voltammetry curves has several reduction waves on the cathodic branch and corresponding oxidation waves on the anodic branch. The first wave A is located in the potential region –(0.0–0.1) V, where the reduction of Ni2+ ions takes place. The second wave B is in the region of potentials –(1.72–1.77) V, on it occurs electroreduction of ions \({\text{LaCl}}_{6}^{{3 - }}\) on nickel electrode with certain depolarization with formation of intermetallide of lanthanum with nickel LaxNiy. The appearance of the third wave C in the potential region –(2.09–2.13) V, we associate with the electroreduction of chloride complexes \({\text{LaCl}}_{6}^{{3 - }}\) on intermetallide LaxNiy with the formation of metallic lanthanum. On the basis of the obtained data it is shown that during the electroreduction of lanthanum chloride complexes in KCl–NaCl melt at T = 973K the nickel electrode interacts with the released lanthanum, causing a significant depolarization of the process of electroreduction of the chloride complex, also formation of intermetallide with Ni electrode occurs.
EFFECT OF CERIUM OXIDE AND BASICITY OF SLAGS ON THEIR VISCOSITY AND CRYSTALLIZATION START TEMPERATURE
Authors: Upolovnikova A. G. , Shartdinov R. R. , Smetannikov A. N.
Published: April 2024

The study of the influence of the content of cerium oxide and the basicity of the slag on the viscosity and temperature of the onset of crystallization of the CaO–SiO2–Ce2O3 system containing 15% Al2O3 and 8% MgO was carried out using the simplex-lattice method of experiment planning, which makes it possible to obtain mathematical models describing the dependence of the property on the composition as a continuous function. Using the experimental data, we built mathematical models that describe the relationship between the temperature of a given viscosity and the composition of the oxide system. Then, by combining the obtained composition-temperature diagrams of a given viscosity on the isothermal section of the composition-viscosity diagram, a set of viscosity isolines was obtained. Generalization of the results of mathematical modeling and graphical display on the isothermal section of the composition-viscosity diagram made it possible to obtain new data on the viscosity of the CaO–SiO2–Ce2O3 oxide system containing 15% Al2O3 and 8% MgO, in the range of basicity 2–5 and the content of 0–15% Ce2O3. Experimental data show that the slags of the studied oxide system, which do not contain cerium oxide, are characterized by an increased crystallization temperature and viscosity in the studied range of basicity. The presence of cerium oxide in the slags of the studied oxide system provides a rather low viscosity and crystallization start temperature in the temperature range of 1500–1550°C. An increase in the content of cerium oxide in slags with a basicity of 2–3 from 1 to 15% is accompanied by a decrease in the crystallization onset temperature from 1490 to 1410°C. Increasing the basicity to 5.0 leads to an increase in the temperature of the onset of crystallization to 1520°C. At a temperature of 1500°C, the viscosity of slags with a basicity of 2.0–3.0, containing 7–15% Ce2O3, varies within 0.2–0.3 Pa · s. An increase in slag basicity to 3.0–5.0 at a fixed Ce2O3 content of 7–15% is accompanied by an increase in slag viscosity up to 1.0 Pa · s and reaches 2.0 Pa · s with a decrease in Ce2O3 to 1–6%. An increase in temperature to 1550°C and a fixed basicity of 3–5 is accompanied by a significant decrease in viscosity, which does not exceed 0.35 Pa · s at a Ce2O3 content of 1–15%.
LARGE-SCALE INHOMOGENETIES AND LONG-TERM RELAXATION IN Al-REM MELTS
Authors: Yagodin D. A. , Son L. D.
Published: April 2024

Long-term relaxation of large–scale inhomogeneities in aluminum – rare earth metal melts with a content of the latter in the range of 5–10 at % was previously observed when measuring viscosity and density, but did not manifest itself when measuring electrical resistance and magnetic susceptibility. This behavior could be related both to the specifics of the measured properties and to the size of the samples, which in the case of viscosity and density is much larger: 12–15 g with a diameter of a cylindrical crucible ~15 mm for viscosity and density, and less than 1 g with a crucible diameter of 6 and 4 mm for electrical resistance and magnetic susceptibility, respectively. To solve this problem, the time dependences of the electrical resistance of the Al91La9 melt were measured at 1060°C for samples of various sizes by the rotating magnetic field method, namely for standard (crucible diameter of 6 mm) and enlarged (crucible diameter of 10.5 mm) When the sample increases, the random measurement error increases, so additional measures had to be taken to stabilize the current in the coils, creating this field. It was found that with an increase in the mass of the sample to 2.15 g with a crucible diameter of 10.5 mm the large-scale heterogeneity that occurs during the melting process is manifested. It is interpreted as a compact “cloud” of intermetallic microparticles surrounded by a melt with a high content of REM. The sample relaxes to an equilibrium homogeneous state in a few hours. To speed up the process, additional exposure is required – heating to a high temperature, about 1500°C, which reduces the time to less than one minute. At the same time, in small (0.7 g with a crucible diameter of 6 mm) samples, the mentioned heterogeneity does not occur. The probable cause of the inhomogeneity is the flow of REM atoms to the surface and the reverse flow of aluminum atoms into the volume during crystallization, which is similar to liquation during the crystallization of cast iron and steel. The measurements carried out allow us to estimate the scale of the resulting inhomogeneities, which corresponds to the size of the enlarged sample.
The Influence of Temperature on the Mechanical Properties of the Surface Layer of a Radiationally Strengthened Fluoropolymer
Authors: Alisin V. V. , Albagachiev A. Yu. , Erofeev M. N. , Yudkin V. F.
Published: April 2024

This article discusses the influence of temperature on the mechanical properties of a fluoropolymer treated by λ irradiation above the melting point. The statement of the high efficiency of this strengthening technology on the tribological properties of the fluoropolymer–steel friction pair is substantiated. The changes in mechanical properties in a thin surface layer of the fluoropolymer as a consequence of heating to 400°C are studied using kinetic microindentation. The material hardness, elasticity modulus, total work of indentation, and its elastic constituent are analyzed. It is proposed to apply friction pairs containing radiationally strengthened fluoropolymer parts in the axial piston pumps of hydraulic systems in order to increase the probability of faultless operation.
Development of an Algorithm for Calculation of the Effective Parameters of a Blast Pulse during Explosive-Reactive Destruction of a Rock Mass
Authors: Solov’ev V. O. , Shvedov I. M.
Published: April 2024

The change in the spectral density of a stress pulse during the operation of an explosive facility in the rock mass is simulated. An algorithm has been developed for calculating the distribution of the spectral density of the pressure pulse for nonstationary gas-dynamic processes, taking into account the physical and mechanical properties of rocks.
Thermal Control: Multifractal Distribution of Local Plastic Strains
Authors: Akhmetkhanov R. S.
Published: April 2024

Methods that make it possible to evaluate the heterogeneity of the distribution of local strains and stresses indirectly through the values of the temperature distribution in thermograms are presented. In this case, methods of fractal analysis in the form of multifractal spectra, image clustering, and multiscale analysis of discrete wavelet images decomposition are used. It is shown that, with increasing damage to the material, the width of the multifractal spectrum increases and local strains are redistributed along the plate length during loading. The use of the multiple-scale wavelet decomposition makes it possible to establish scale elements that have the greatest strain changes.
Optimization of the Properties of Materials Based on Compressed Wood Used in the Structures of Oil-Field Machinery and Mechanisms
Authors: Guliev A. , Sharifova A. , Yusubov F.
Published: April 2024

This article is devoted to the study of plain bearings made of pressed wood, lubricated and cooled with water in order to establish the features of their calculation and design. In connection with the development of the industry that produces plastics that can replace nonferrous metals, this issue is of particular importance. In guides and plain bearings, characterized mainly by low sliding speeds, pressed wood and materials based on it are used successfully. Materials based on pressed wood have good tribological properties. Pressed wood is easily modified to give it the desired properties. It is promising for use in movable mates that operate without lubrication.
Centralized Restoration of Parts at the Enterprises of the Soyuzselkhoztekhnika and Goskomselkhoztekhnika Systems
Authors: Lyalyakin V. P. , Kravchenko I. N. , Korneev V. M.
Published: April 2024

Our country has been undergoing processes related to the reorganization and improvement of agricultural production services. The Soyuzselkhotechnika system was organized to replace the machine-technological stations. The development dynamics of Soyuzselkhotekhnika shows the volumes of marketable products, and it is particularly noted that the markup on all services used to be only 12.6%, and now it has risen to 45%. The volumes of reconditioning of parts at the enterprises of Soyuzselkhotekhnika are given; more than 60% of the names of parts were restored. Achievements of individual enterprises in the implementation of efficient technologies are shown. It is confirmed that the reconditioning of worn parts at the enterprises of Soyuzselkhotekhnika annually saved for the country up to 12% of new spare parts, over 500 000 tons of casting, and 150 000 tons of rolled products. The role of sectoral science and academic science is shown. The created system of Soyuzselkhotekhnika enterprises was an effective assistant for commodity producers not only in providing new machines and assemblies, but also for remanufactured parts with high quality, low price, and guaranteed performance.
Comparative Analysis of a Numerical Method and Machine Learning Methods of Temperature Determination of a Doped Lubricating Layer with Experimental Data
Authors: Tokhmetova A. , Albagachiev A. Yu.
Published: April 2024

This article compares machine learning methods and a numerical method of determination of the doped lubricating layer with experimental data. Based on the sweep method, the one-dimensional Fourier heat equation with boundary and initial conditions is solved. As a result of comparing numerical and predictive data with experiments, it can be concluded that machine learning models are better at predicting results compared to numerical data
Fretting Wear of Metal–Metalopolymer Friction Couples
Authors: Albagachiev A. Yu. , Gantimirov B. M.
Published: April 2024

Test results on fretting wear of metalopolymer materials in a friction couple with structural materials—cast iron 20 and stainless steel 12Kh18N10T—performed over the direct and reverse test schemes are presented. As the metalopolymer material, we took the BELZONA 1111 two-component paste-like material based on a mixture of a metal–ceramic alloy with high-molecular polymers and oligomers.
Improving the Sealing Efficiency of Compressor Cylinders of Gas Engine Compressors in the System of Gas-Lift Production of Offshore Fields
Authors: Aliev V. I. , Gasanov I. I.
Published: April 2024

An increase in the efficiency of gland seals in compressor cylinders with cast iron rings pressed against the contact surface of the piston rod using a steel spring in reciprocating compressors used in offshore oil and gas-condensate fields for gas-lift oil production systems is considered. Studies of a gas engine reciprocating compressor working directly on the operating gas-lift system have shown that in order to increase the time of normal operation of gland seals, it is necessary to adjust the clearance using lubricant up to 0.1 mm. After increasing the spring stiffness, the serviceability and number of working hours of the gland seal increased twofold, from 850 to 1700 h.
Influence of the Reinforcement Structure and Boundary Conditions on the Stability of Quadrangular Composite Panel
Authors: Azikov N. S. , Zinin A.
Published: April 2024

An analysis of the stability of quadrangular orthotropic composite panels under compression and shear is presented. The stability problem is solved by the Rayleigh–Ritz method in displacements with approximation of the deflection eigenmodes by Krylov functions. An assessment is made of the influence of fastening conditions and the laying pattern of layers of a composite structure on the parameters of the critical behavior of quadrangular panels. The accuracy of the numerical procedures is confirmed by comparison with the results of the exact solution of the main linearized equation of stability theory using the example of an isotropic plate.
The Technique of Tribological Studies of SiSiC High-Speed Thrust Bearings
Authors: Erofeev M. N. , Splavskiy I. S.
Published: April 2024

This paper is devoted to model tribological experiments and analysis of the research results obtained for new materials and coatings, such as SiSiC, with the aim to rank them and to make recommendations for use in thrust hydrodynamic friction units operating at high speeds and loads.
Effect of Resonance-Wave Actions on Sedimentation Stability of Starch Nanoparticle Dispersions
Authors: Ganiev S. R. , Kasilov V. P. , Kislogubova O. N. , Butikova O. A. , Kochkina N. E.
Published: April 2024

The influence of resonance wave effects on the sedimentation stability of potato and corn starch nanoparticle dispersions obtained by coprecipitation was studied. It has been established that the proportion of the dispersed phase of potato starch nanoparticle dispersions formed using traditional mixing remains unchanged for two days. For corn starch nanoparticle dispersions, this indicator remains at the initial level only for the first five minutes. The use of wave action at the stage of coprecipitation leads to an increase in the values of the ξ-potential of the obtained nanoparticles by 4.5 and 3.5 times for corn and potato starches, respectively. Due to this, the dispersion stability of corn starch nanoparticles increases up to two days and dispersions of potato starch nanoparticles increase up to forty days. The results presented in this article are the basis for the development of a resource-saving technology for obtaining highly stable dispersions of biopolymer nanoparticles for food, medical, pharmaceutical, and other industries.
Study of the Influence of Macrogeometry Parameters on the Tightness of Shaft–Seal Joints
Authors: Leonov O. A. , Shkaruba N. Zh. , Grinchenko L. A. , Pupkova D. A. , Khasyanova D. U.
Published: April 2024

The factors influencing the reliability and durability of the joint between a shaft and a rubber reinforced seal are analyzed. It has been established that the theory of tightness of such joints has not yet been developed. The quality of a joint is usually assessed by the amount of leakage. It has been revealed that the amount of leakage depends on the materials from which the shaft and seal are manufactured, the roughness of the shaft surface, the presence of dust in the friction zone, the quality of the sealed liquid, and the operating temperature. In addition, the durability of the work is influenced by macrogeometry parameters like deviation from the perpendicularity of the seal to the shaft, deviation from coaxiality, and radial runout of the shaft. A multifactorial experiment has been carried out, as a result of which an empirical relationship has been established between the radial runout of the shaft, rotational speed, and interference in the joint according to the criterion of the onset of leaks. Analysis of the obtained dependence showed that the radial runout should be compensated by interference in the joint, and with an increase in the rotation speed, the compensation value should be greater due to the fact that the working edge of the seal does not have time to follow the shaft. An empirical relationship between the amount of interference and leakage has been obtained, which indicates that with lower interference, leakage will be greater. The research results can be used at the stage of designing assembly units with seals to reduce the influence of radial runout and deviations from the coaxiality of the shaft relative to the seal.
A Safety Device Based on a High Temperature Shape Memory Alloy
Authors: Popov N. N. , Presnyakov D. V. , Kostyleva A. A.
Published: April 2024

A device has been developed based on alloys with a high-temperature shape memory effect. It aims to be used in mechanical engineering products, in particular, nuclear technology, in order to prevent emergency situations of man-made and natural nature. The device works by breaking the electrical circuit in the event of an emergency increase in the ambient temperature above the permissible temperature by cutting the electrical cable. The shape restoration properties of thermosensitive working elements made of the Ni49.5Ti48.0Hf2.5 alloy with high temperature shape memory have been studied. The results of the experiments allow us to conclude that it is possible to use the device in electrical systems for cutting heat-resistant electrical cables with an outer diameter of dout = 3.4–5.0 mm and a copper wire cross-section of 0.2–1.5 mm2 with a knife in an emergency situation, when the ambient temperature exceeds 100°С and the maximum heating reaches 200°С.
SDSS J085414.02+390537.3—A New Asynchronous Polar
Authors: Kolbin A. I. , Suslikov M. V. , Kochkina V. Yu. , Борисов N. V. , Burenkov A. N. , Oparin D. V.
Published: April 2024

Based on data from the ZTF photometric survey, we have revealed asynchrony of the polar SDSS J085414.02+390537.3. A beat period Pbead=24,6+0,1 days, during which the system changes its brightness by =3m, is distinguished in the light curves. Power peaks at the white-dwarf rotation period Pspin=113.197+0,001 min and orbital period Porb=113,56+0,001 min are revealed in the periodograms, with the corresponding polar asynchrony being 1-Porb/Pspin=0,3%. The photometric behavior of the polar points to a change of the main accreting pole during the beat period. Based on the Zeeman splitting of the Hb line, we have estimated the mean magnetic field strength of the white dwarf to be B=28,5+1,5 MG. The magnetic field strength near the magnetic pole has been found by modeling the cyclotron spectra to be B=34+2 MG. The Doppler tomograms in the Hb line exhibit a distribution of emission sources typical for polars in velocity space with evidence of the transition of the accretion stream from the ballistic trajectory to the magnetic one.
Strong Scattering Effects in the Emission of Soft Gamma-Ray Bursts
Authors: Urvachev T. M. , Shidlovski D. S. , Blinnikov S. I. , Glazyrin S. I.
Published: April 2024

When a light beam enters a scattering-dominated medium, the radiation is isotropized. Part of the radiation goes backwards, leading to non-monotonicity in the radiation energy density profile inside this medium. There arises a local maximum at which the energy density at a scattering albedo 1 is severalfold greater than that without scattering at the same extinction. This effect is studied numerically in one-dimensional and two-dimensional simulations. It is demonstrated that a local maximum of the radiation energy density arises in the medium, whose value depends on the optical depth of the region. This effect can manifest itself, for example, when the radiation from a gamma-ray burst (GRB) enters heated regions in the interstellar medium. The presence of scattering in the GRB radiation generation region, near the front of strong shocks, affects the radiation pattern. The structure of such shocks is remarkable for the presence of a preshock preheating tail. Strong scattering in this region leads to the escape of a significant fraction of the radiation sideways and backwards in the shock reference frame, forming additional tails in the angular distribution of GRB radiation after the relativistic transformation to the laboratory frame. This effect is also studied numerically in three-dimensional simulations.
Induced Magnetic Field in Accretion Disks around Neutron Stars
Authors: Kuzin A. V.
Published: April 2024

In pulsating X-ray sources a magnetized neutron star is surrounded by an accretion disk whosestructure requires a study. In particular, the dipole magnetic field of the star can partially penetrate the diskand, freezing into the matter, can give rise to an induced magnetic field in the disk. The field growth can belimited by its turbulent diffusion. In this paper we calculate such an induced field. The problem is reduced tosolving the induction equation in the presence of diffusion. An analytical solution of the equation has beenobtained, with the radial and vertical structures of the induced field having been calculated simultaneously.The radial structure is close to the previously predicted dependence on the difference of the angular velocitiesof the disk and the magnetosphere: b ∝ Ωs − Ωk, while the vertical structure of the field is close to the linearproportionality between the field and the height above the equator: b ∝ z. The possibility of the existence ofnonstationary quasi-periodic components of the induced magnetic field is discussed.
Detection of Radio Emission from the Geminga-Like
Gamma-Ray Pulsar J1836+5925
Authors: Malofeev V. M. , Malov O. I. , Teplykh D. A. , Timirkeeva M. A.
Published: April 2024

The detection of radio emission from the gamma-ray pulsar J1836+5925 is reported. Rare events of radio emission from this object have been recorded with the LPA radio telescope at the Pushchino Radio Astronomy Observatory. A two- or three-component integrated profile and very narrow individual pulses are a peculiarity of the radio emission from the pulsar J1836+5925. The presence of an interpulse is also possible. We have measured the dispersion measure, DM = 23 ± 1 pc cm−3, and estimated the distance to the pulsar, 1.5 kpc. The flux density and the lower limit on the spectral index have been estimated.
Influence of Space Curvature on the Moment of Inertia of a Pulsar Magnetic Field
Authors: Matevosyan A. A. , Barsukov D. P.
Published: April 2024

We consider the influence of space curvature in the Schwarzschild metric on the contribution of the magnetic field outside the neutron star to the moment of inertia of a radio pulsar. Our considerationis restricted only to the simplest configuration of the magnetic field, when it can be described by only one harmonic. We show that at a fixed magnetic field strength on the stellar surface the influence of space curvature reduces the contribution of the magnetic field outside the star to the departure of the inertia tensor from the spherical one several-fold.
Testing the Hypothesis about the Existence of a Planet Orbiting the Pulsar B0329+54 (J0332+5434)
Authors: Potapov V. A. , Andrianov S. A.
Published: April 2024

We have analyzed the results of our observations of the millisecond pulsar B0329+54 (J0332+5434), which exhibits quasi-periodic variations in the barycentric times of arrival (TOAs) of pulseson long time scales. We have tested the hypothesis about the existence of a planet with a mass close to the mass of the terrestrial planets and an orbital period of 27.8 yr around this pulsar that was proposed previously to explain the variations in its TOAs. We show that this hypothesis is not confirmed when considering the series of TOA residuals over the entire available time interval of observations 1968–2022 and that the TOA variations for this pulsar apparently have a different physical cause.
Investigation of the Disk of the Be Star in the High-Mass X-ray Binary
IGR J21343+4738
Authors: Nikolaeva E. A. , Bikmaev I. F. , Irtuganov E. N. , Gorbachev M. A. , Suslikov M. V. , Gumerov R. I. , Sakhibullin N. A.
Published: April 2024

We present the results of our long-term photometric and spectroscopic monitoring with the1.5-m telescope RTT-150 for the optical counterpart of the high-mass X-ray binary IGR J21343+4738discovered in 2002 by the INTEGRAL space X-ray observatory. The X-ray source was also repeatedlydetected by the telescopes of the SRG observatory during the all-sky surveys in the period 2019–2021.We have investigated the spectroscopic and photometric variabilities of the optical counterpart, a Be star,caused by physical processes in the equatorial disk. We have analyzed the evolution of the equatorial diskparameters on a long time scale of 16 years.
X-ray Properties of the Luminous Quasar PG 1634+706 at z = 1.337
from SRG and XMM-Newton Data
Authors: Uskov G. S. , Sazonov S. Yu. , Gilfanov M. R. , Lapshov I. Yu. , Sunyaev R. A.
Published: April 2024

In the fall of 2019, during the in-flight calibration phase of the SRG observatory, theonboard eROSITA and Mikhail Pavlinsky ART-XC telescopes carried out a series of observations ofPG1634+706—one of the most luminous (an X-ray luminosity ∼1046 erg s−1) quasars in the Universe atz 2. Approximately at the same dates this quasar was also observed by the XMM-Newton observatory.Although the object had already been repeatedly studied in X-rays previously, its new observations allowedits energy spectrumto be measuredmore accurately in the wide range 1–30 keV (in the quasar rest frame).Its spectrum can be described by a two-component model that consists of a power-law continuum with aslope Γ ≈ 1.9 and a broadened iron emission line at an energy of about 6.4 keV. The X-ray variability of thequasar was also investigated. On time scales of the order of several hours (here and below, in the sourcerest frame) the X-ray luminosity does not exhibit a statistically significant variability. However, it changednoticeably from observation to observation in the fall of 2019, having increased approximately by a factorof 1.5 in 25 days. A comparison of the new SRG and XMM-Newton measurements with the previousmeasurements of other X-ray observatories has shown that in the entire 17-year history of observationsof the quasar PG 1634+706 its X-ray luminosity has varied by no more than a factor of 2.5, while thevariations on time scales of several weeks and several years are comparable in amplitude.
Optical Identification and Spectroscopic Redshift Measurements
of 216 Galaxy Clusters from the SRF/eROSITA All-Sky Survey
Authors: Zaznobin I. A. , Burenin R. A. , Belinski A. A. , Bikmaev I. F. , Gilfanov M. R. , Dodin A. V. , Dodonov S. N. , Eselevich M. V. , Zheloukhov S. G. , Irtuganov E. N. , Kotov S. S. , Krivonos R. A. , Lyskova N. S. , Malygin E. A. , Meshcheryakova N. А. , Medvedev P. S. , Meshcheryakov A. V. , Moiseev A. V. , Oparin D. V. , Potanin S. A. , Postnov K. A. , Sazonov S. Yu. , Safonov B. S. , Sakhibullin N. A. , Starobinsky A. A. , Suslikov M. V. , Sunyaev R. A. , Tatarnikov A. M. , Uskov G. S. , Uklein R. I. , Khabibullin I. I. , Khamitov I. M. , Khorunzhev G. A. , Churazov E. M. , Shablovinskaya E. S. , Shatsky N. I.
Published: April 2024

We present the results of the optical identification and spectroscopic redshift measurements of216 galaxy clusters detected in the SRG/eROSITA all-sky X-ray survey. The spectroscopic observationswere performed in 2020–2023 with the 6-m BTA telescope at the Special Astrophysical Observatory ofthe Russian Academy of Sciences, the 2.5-m telescope at the Caucasus Mountain Observatory of theSternberg Astronomical Institute of the Moscow State University, the 1.6-m AZT-33IK telescope atthe Sayan Solar Observatory of the Institute of Solar–Terrestrial Physics of the Siberian Branch of theRussian Academy of Sciences, and the 1.5-m Russian–Turkish telescope (RTT-150) at the TU¨ BI˙ TAKObservatory. For all of the galaxy clusters presented here the spectroscopic redshift measurements havebeen obtained for the first time. Of these, 139 galaxy clusters have been detected for the first time in theSRG/eROSITA survey and 22 galaxy clusters are at redshifts zspec 0.7, including three at zspec 1.Deep direct images with the rizJK filters have also been obtained for four distant galaxy clusters atzspec 0.7. For these observations we chose the most massive clusters and, therefore, most of the galaxyclusters presented here with the spectroscopic redshifts measured by us will most likely enter in future intothe cosmological samples of galaxy clusters from the SRG/eROSITA survey.
Influence of a Small-Scale Magnetic Field on the Heating
of the Polar Cap of the Radio Pulsar J0901–4046
Authors: Barsukov D. P. , Morozov I. K. , Popov A. N.
Published: April 2024

The pulsar J0901–4046 has a spin periodP = 75.8 s and is themost slowly rotating one amongthe isolated radio pulsars. We have considered the influence of a small-scale magnetic field in the offcentereddipole model on the polar cap heating by the reverse positron current in the inner gap of the pulsar.We have assumed that the electron–positron pairs in the gap are created in bound states, which then arebroken by thermal photons from the stellar surface.
Flute Instability Effects for Disk Accretion onto Neutron Stars
with Strong Magnetic Fields
Authors: Lisitsin D. D. , Shakura N. I.
Published: April 2024

The flute instability at the inner edge of a thin diamagnetic accretion disk is analyzed. Themagnetic field configuration model fromAly (1980) is used. We have analyzed a modified dispersion relationfor the flute instability that takes into account the Keplerian disk rotation. We have derived the inner radiusof the accretion disk within our analysis of the flute instability.We show that the inner radius does not differfrom the Alfve´ n radius for spherical accretion to within a dimensionless coefficient, with the proportionalitycoefficient depending only on the turbulence alpha parameter and the relative disk thickness (h/r).