bluuebunny/crossref_metadata_2025 huggingface dataset:
Using of direct piezo-discharge in generation of plasma-activated liquid media
Authors: Konchekov E M , Gusein-zade N G , Kolik L V , Artem’ev K V , Pulish A V
Published: May 2020

This article shows the possibility of plasma-activated liquid media generation using the least energy-consuming source of low-temperature plasma, based on the use of a piezoelectric transformer. The experiments determined the possibility of producing reactive oxygen and nitrogen species in deionized water and culture media. The concentrations of H2O2 and NOx were estimated depending on the energy deposition.
Study of the effect of crystallization conditions on the structure of polyurethane block copolymer based on poly-ε-caprolactone diol and isophoron diisocyanate
Authors: Gorbunova M A , Lelecova V A , Shukhardin D M , Malkov G V , Anokhin D V , Badamshina E R
Published: May 2020

In the paper a study of isothermal crystallization kinetics of polyurethane on the basis of poly-ε-caprolactone diol, isopforon diisocyanate and 1, 4-butanediol is presented. The process of isothermal crystallization in the temperatures range from -15 to 30ºC was studied by DSC method. Analysis of total melting enthalpy and degree of crystallinity of the polyurethane allows to obtain material with one or two melting points of polyester block at desired temperature. These results will help in design of new thermoplastic elastomers with one- or two-stage shape memory effect.
Effect of synthesis parameters on the structure and properties of carbon particles formed from amorphous fullerites
Authors: Lukina I N , Chernogorova O P , Drozdova E I , Ekimov E A , Apostolova M O , Prokopenko D A , Soldatov A V , Benavides V
Published: May 2020

The effect of high-pressure synthesis temperature on the structure and indentation characteristics of the superelastic hard carbon formed from amorphous fullerites and on the tribological properties of the Co-based composite materials (CM) reinforced by the particles of such carbon has been studied by Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), indentation measurements, and tribological tests. It is shown that ball milling (for 48 h) of C60 fullerite crystals results in the amorphization of the product of fullerite transformation upon their high-pressure treatment at temperatures above the stability limit of fullerene molecule (∼800°C). An increase in synthesis temperature at 8 GPa from 800°C to 1200°C leads to a gradual graphitization of the structure of amorphous fullerite derived carbon. This decreases its hardness and indentation modulus from 32 to 18 GPa and from 256 to 95 GPa, respectively, and increases the elastic recovery (from 80% to 86%). The best tribological characteristics of the CM are attained at the maximum particle hardness, which is realized in the CM synthesized at 800°C. When the synthesis temperature is elevated to 1200°C, the friction coefficient and wear rate of the CM increase, but they remain substantially lower than those of the matrix cobalt.
Scandium extraction from multicomponent systems by crystallization of complex sulfates
Authors: Pasechnik L A , Medyankina I S , Yatsenko S P
Published: May 2020

Red mud generated from alumina production is one of the most promising scandium resources. Leaching for concentrating scandium and other valuable metals is often performed with the use of acid solutions in specially selected conditions. Different precipitants can be employed for selective precipitation of scandium in the form of poorly soluble compounds. A new method for the crystallization of ammonium scandium sulfates from sulfuric solutions was carried out in this study. Depending on the ammonium cation concentration, precipitation is possible in the form of NH4Sc(SO4)2 or (NH4)3Sc(SO4)3. The solubility values for NH4Sc(SO4)2 and (NH4)3Sc(SO4)3 in water established by the isothermal saturation method were 9.02 and 12.89 g/l Sc2O3, respectively. Complete precipitation of the most promising gravimetric form of scandium represented by NH4Sc(SO4)2 was achieved at 5-6 M H2SO4 and 0.5 M NH4
+. The product of crystallization from sulfuric solution used for treating poor scandium concentrate produced from red mud is a mixture of polymorphs of the composition NH4Sc(SO4)2. Co-precipitated impurities of Al, Fe, Ti, Zr etc. are separated after repeated dissolution and precipitation of ammonium scandium sulfate under analogous conditions. The recrystallization product after calcination at 1000°C contains 99% Sc2O3.
Sintering and physico-mechanical properties of materials based on silicon nitride nanoscale powders
Authors: Perevislov S N , Lukyanova O A , Lysenkov A S , Kim K A , Vysotin A B
Published: May 2020

Obtained a high-density material (p = 3, 28 g/cm3, a porosity of 1, 4 %) on the basis of silicon nitride powder by liquid phase sintering nanoscale. Displaying pressing pressure on the density of sintered materials the based silicon nitride. The process of pattern formation material during sintering. The main physico-mechanical characteristics: the density, porosity and grain size of the solid phase, the modulus of elasticity, flexural strength, fracture toughness ratio, Vickers hardness.
Studying the properties of carbides in the system ZrC–HfC, TaC–ZrC and TaC–HfC
Authors: Perevislov S N , Vysotin A B , Yu Shcherbakova O
Published: May 2020

Considers the chemistry of carbides of zirconium, hafnium and tantalum and their high temperature properties. By hot pressing the obtained dense materials in the systems ZrC– HfC, TaC–ZrC, and TaC–HfC analysed their microstructure, physical and mechanical properties.
Structural changes after high-speed impact of tungsten powder with a steel target
Authors: Petrov E V , Trofimov V S , Saikova G R , Kopytskiy V O
Published: May 2020

Shock-wave high-velocity impact of tungsten powder with a steel target was studied in the work. It is determined that shock wave treatment of the samples leads to a refinement, flattening and stretching of ferrite and perlite grains in the surface layer. The structural transition from plate perlite in the near-surface layer of the target to coarse-plate perlite in the bulk of the target, the microstructure of which does not differ from the microstructure of the initial sample, was detected in the structure of U8 steel after a particle flux. It is found that cellular supercooled austenite with tungsten carbide mesh along grain boundaries is formed in the structure of steel. The microhardness of the target in depth after exposure to tungsten particles is analyzed. It was shown that the microhardness distribution along the width of the sample is wave-like, and the microhardness decreases monotonically along the depth of the sample. The microhardness maximizes by 24% at a distance of 4 mm from the surface compared to the original microhardness.
Oxidation and biodegradation of polymeric composites based on polylactide: structure and properties
Authors: Podzorova M V , Tertyshnaya Yu V
Published: May 2020

Polymer blends of polyethylene – polylactide of different composition were obtained and studied. Thermal degradation was investigated in the temperature range from 20 to 700 °C. It is shown that the polyethylene more resistant to the effects of temperature (peak of destruction - 414 °C) than polylactide (peak degradation – 364 °C). In blends with increasing polyethylene content in the matrix increases the maximum temperature of thermal degradation. The process of thermal oxidation carried out at temperatures of 80, 90, 110 °C and a pressure of 300 Torr. Binary polylactide–low-density polyethylene blends of various compositions were prepared, and their biodegradability in soil. The weight loss is higher upon incubation in laboratory soil compared to open soil.
METALS RECOVERY FROM MOLYBDENITE CONCENTRATE BY ELECTROOXIDATION AND LEACHING
Authors: Rasulova S N , Guro V P , Safarov E T , Adinaev X F
Published: May 2020

Mineral resources today are increasingly determined by the concept of “persistent”. The reason for their difficult opening is in the composition of sulfide nature, leading to passivation of the surface and inhibition of hydrometallurgical processes. The way out in practice was found in oxidative firing and some other technologies. The work compares the results of leaching of molybdenite concentrate of Almalyk MMC JSC according to the schemes: the existing calcining-ammonia and non-calcining with nitric acid, hypochlorite opening and leaching. Non-calcining with hypochlorite opening and leaching scheme is not only ecologically cleaner in compare with pyro-metallurgy, but it relocates quantitatively to the solution not only molybdenum, rhenium, but gold and silver as well.
Study of sintered aluminum materials with nanoparticles microadditions
Authors: Agureev L E , Savushkina S V , Laptev I N , Ivanov B S , Ivanov A V , Kostikov V I , Eremeeva Zh V
Published: May 2020

Sintered aluminum materials with small additions (0.01-0.15 vol.%) of aluminum, zirconium and magnesium oxide nanoparticles were obtained by powder metallurgy. The microstructure of the samples and the effect of the nature and concentration of nanoparticles on the matrix grain size, density, microhardness, and corrosion resistance in 10% solutions of nitric and sulfuric acids were studied. The addition of nanoparticles led to matrix grains decrease, an increase in the density, microhardness, and corrosion resistance of sintered aluminum samples. The lowest value of grain size was shown by the sample with 0.1% vol. magnesium oxide. Sintered aluminum material with 0.05% vol. zirconium oxide nanoparticles had the highest density∼ 2.67 g/cm3. The highest Vickers microhardness at the level of 0.474 GPa was obtained for material with the addition of 0.1 vol.% Al2O3 nanoparticles. All samples showed significantly greater corrosion resistance in comparison with pure sintered aluminum. The samples with nanoparticles withstood 30 hours of testing, and pure aluminum dissolved in nitric acid in 15 hours, and in sulfuric acid in 10.
Research of thermoradiation properties and expansion of tantalum carbide at high temperatures
Authors: Senchenko V N , Belikov R S , Tenishev A V
Published: May 2020

The article describes an experimental method for studying of the thermophysical properties of refractory carbides, in particular for studying thermal expansion and radiation spectra of the sample during millisecond pulse electrical heating. As a result emission spectra of tantalum carbide were obtained in the temperature range 2400-3000 K. Also the data obtained make it possible to determine the coefficient of thermal expansion and thermoradiation properties of high refractory carbides, in particular for tantalum carbide.
Optimization potential of anaerobic biocatalytic processes using intracellular ATP concentration as the main criterion for decision making
Authors: Senko O V , Maslova O V , Efremenko E N
Published: May 2020

The effective use of such an analytical indicator as the concentration of intracellular adenosine triphosphate (ATP) in the process of anaerobic transformation of sulfones was shown. The bioluminescent method for determining ATP evaluates to quickly evaluate the state of biocatalysts in such processes, to select the conditions for effective conducted of biotechnological processes and the functioning of cells, as well as media compositions used in the conversion of sulfur-containing compounds.
Study of high-frequency magnetic properties of Fe-Ti-B films obtained by magnetron sputtering
Authors: Sheftel E N , Harin E V , Tedzhetov V A , Sh Usmanova G , Bobrovskii S Y , Rozanov K N , Zezyulina P A , Kiryukhantsev-Korneev Ph V
Published: May 2020

The Fe-Ti-B films were obtained by dc magnetron sputtering of the Fe + 15% TiB2 and Fe + 30% TiB2 targets. The chemical composition and structure were studied in the as-sputtered state and after vacuum annealing at 500°C. The static (saturation magnetization Ms
and coercive field Hc
) and rf magnetic properties (magnetic permeability µ’, frequency of natural ferromagnetic resonance fr
and the frequency range in which µ’ is kept) were determined.
Study of the effect of the catalyst on the mechanical properties of RTV grade siloxane
Authors: Tsareva A M , Nasakina E O , Sudarchikova M A , Balashov E P , Baikin A S , Shatova L A , Sevost’yanov M A
Published: May 2020

A RTV grade siloxane film with a different percentage of catalyst was obtained. The mechanical properties of polymer films based on RTV grade siloxane are studied, as well as the effect of K-18 catalyst concentration on thickness, strength and ductility the properties of the obtained films was shown.
The development of the high-strength corrosion resistant austenitic steels for the oil equipment shafts
Authors: Muradyan S O , Muradyan O S , Kostina M V , Kostina V S
Published: May 2020

The work proposes to use corrosion-resistant austenitic Fe-Cr-Mn-Ni-Mo-N steel with a nitrogen content of ∼ 0, 4-0, 9% as a material for the shafts of the oil equipment. The steel was hardened by the solid-solution hardening. Previously, such materials in this area were not used.
Research and development of the inert gas atomization of the wire by means of arc spraying
Authors: Yu Ivannikov A , Kirsankin A A , Kalayda T A , Sevostyanov M A
Published: May 2020

The paper presents brief information on the theory and technology of electric arc wire spraying. The construction for spraying of four groups of wire materials is shown. Carbon and stainless steel, pure copper and titanium wires were atomized. A model of wire atomization during process of electric arc spraying is described.
Formation of Si3Al3O3N5 oxonitride from mixtures of xerogels and silicon and aluminum nitrides in the nitrogen atmosphere
Authors: Ivicheva S N , Klimashin A A , Ovsyannikov N A , Lysenkov A S , Kargin Yu F
Published: May 2020

To obtain silicon and aluminium oxonitrides, the transformations of xerogels and nitrides during firing in a nitrogen atmosphere were studied by thermal and x-ray phase analysis. It was established that the interaction between nitrides and xerogels in a nitrogen atmosphere with the formation of oxonitrides is due to reduction-nitriding reactions. The CO and hydrogen which are formed during the pyrolysis of adsorbed and chemisorbed alcohols (which are the products of the hydrolytic decomposition of silicon and aluminium alkoxides in xerogels) is a reducing agent for the finely dispersed oxides. The effect of the composition of the initial mixtures on the phase composition of the final product (SiAlON) and the morphological features of the powders obtained in one stage of firing in a nitrogen atmosphere is shown.
Properties of composites SiC/SiCf obtained by hot pressing of SHS of silicon carbide powder
Authors: Frolova M G , Lysenkov A S , Titov D D , Istomina E I , Perevislov S N , Kim K A , Zakorzhevsky V V , Fedorov S V , Kargin Yu F
Published: May 2020

Dense ceramic samples based on SiC were obtained by hot pressing. We used the Use of silicon carbide powder as the initial components of SHS, due to the spherical shape of the particles, allows obtaining a denser workpiece. The reinforcing component in the form of silicon carbide fibers is obtained by siliconizing carbon fabric with SiO vapours. The phase composition of SiC fibers obtained by silicification by SiO vapour was determined. The properties of the obtained SiC/SiCf composites were studied: density 3.20 g/cm3, strength 520 MPa (for monolithic ceramics 390 MPa), the value of the crack resistance coefficient 5.9 MPa-m1/2.
Optimization of On-Site Xylanase Production from Aspergillus niger via Central Composite Design (CCD)
Authors: Tarrsini M , Ng Q H , Teoh Y P , Kunasundari B , Ang W U , Shuit S H , Ooi Z X , Hoo P Y
Published: May 2020

Xylanases have stimulated considerable interest due to their potential application in several industries, especially in the bioethanol sector. Since the vitality of this enzyme is undeniable, this research is focused on optimization of on-site xylanase production from Aspergillus niger (A. niger). This initiative could reduce the dependence of commercial xylanase. Central Composite Design (CCD) was implemented in the process of xylanase production optimization. Incubation temperature and medium pH were two parameters selected to statistically optimized using Response Surface Methodology (RSM) in order to improve the xylanase production. From the data analyzed by Design of Experiment (DoE), maximal xylanase production was predicted to produce under condition of 32.67 °C and pH 4.56 with desirability of 0.936. A validation test with triplicate was done to verify the predicted result. The maximum enzyme activity of 0.5638 U/mL was obtained from the validation test.
Overview of the II International Conference “MIP: Engineering-2020: Modernization, Innovations, Progress: Advanced Technologies in Material Science, Mechanical and Automation Engineering”
Authors: Kovalev Igor V , Voroshilova Anna A
Published: May 2020

The overview describes the main directions and results of the II International Conference MIP: Engineering-2020 held in Krasnoyarsk in April 16-18, 2020. It gives the details about the participants and the proceedings.
Design and technology reliability analysis: fork
Authors: Artyushenko A G , Pokhabov Yu P
Published: May 2020

While space system functioning, faults are unacceptable. The price of any early failure in the operation of a spacecraft is much higher than the cost of the development and manufacture of the failed element. Modern verification methods do not provide the required reliability. For the mechanisms of spacecraft, a methodology of design and technology reliability analysis has been developed, which allows one to achieve reliability, which is not available for modern verification methods. The article provides the purpose of the new analysis, the basic foundations and a brief description of the analysis methodology. The technique was tested in the development of space-based mechanisms and hydraulic automation for oil equipment that operate without human intervention once during the service life. The basic approaches to the implementation of the design and technology reliability analysis make it possible to develop many branches (fork version) to solve problems of ensuring the quality and reliability of products for various purposes, increasing the efficiency of development and professional skill of designers.
Environmental monitoring and its methods and technical means of environmental protection in the area of technical responsibility of oil and gas industries
Authors: Topchiev A G
Published: May 2020

The paper aims to reason the need to create a system of local air monitoring system which functions in interaction with monitoring systems located on the orbital space platforms. A comparative analysis of drones and aircraft of the ultra-light class as platforms for carrying out on-board aerial survey equipment has been performed. The configuration and functioning principles of an interactive on-board local monitoring system protected by patents of the Russian Federation are discussed. The advantages of the local air monitoring system designed for the implementation of environmental protection projects in the oil and gas infrastructure are analyzed. The scope and the list of functional tasks to be solved in the interests of the oil and gas industry of the Russian Federation are determined.

A post-publication change was made to this article on 11 Jun 2020 to correct the pdf so that it matched the webpage.
Dislocation structure of dicotyledonous bimetals under external harmonic influence: molecular dynamics modeling
Authors: Zakharov P V , Eremin A M , Safronova S A , Markidonov A V , Starostenkov M D
Published: May 2020

In this article, we study the structure of the network of dislocations near the boundary of a dicotyledonous bimetal Ni-Al under intense external harmonic influence. The method of molecular dynamics was chosen as the method, using potentials obtained by the immersed atom method. The paper analyzes the behavior of dislocation segments as a function of the intensity of exposure in the presence of vacancies near the boundary of a bipartite bimetal. It is shown that the frequency of exposure significantly affects the change in the structure of bimetal. In this case, point defects in the form of vacancies play an important role. The analysis was carried out by heating the calculated cells, the temperature of which is not more than half the melting temperature of the materials. Comparison with annealing of defects showed that structural changes in dislocations occur at lower temperatures, and their flow rate is higher.
Training specialists in material sciences and aerospace engineering using the interactive educational environment
Authors: Dubovitskaya T V , Tatyanina E P , Turaeva T L , Habarova O S , Zaslavskaya O Yu
Published: May 2020

The article considers the actual topic of using a computerized educational environment through an interactive whiteboard in the process of training specialists in the field of materials science and aerospace engineering at a university. The use of technical teaching aids in practical classes is becoming very common in modern educational practice. It allows the educational process to be carried out in new conditions, when the teacher ceases to be the only source of information for students. The article reveals the possibilities of using an interactive whiteboard in practical classes, provides examples of the use of this learning tool when studying certain topics from a physics course.
Compressor disc structural optimization for gas turbine engine
Authors: Hoang Nhat Minh , Chu Duy Lanh , Nguyen Phi Minh , Nguyen Tien Quyet
Published: May 2020

Gas turbine engine compressor increases the pressure and temperature of the air stream through it before entering the combustion chamber. Due to the extreme in rotational speed and high temperature, the gas turbine engine compressor is subjected to a complex force system that causes different failures mode in the compressor disc. Therefore, the design and calculation of compressor discs always consist of very high requirements with the problem of reducing the volume and increasing the durability of the disc structure. This paper presents a computational method that optimizes the design of a compressor disc geometry that meets performance and durability parameters but has the lowest mass based on finite element method. The calculation program is implemented by software Abaqus 6.13, algorithms and analysis results are processed through the Python 3 programming language.

A post-publication change was made to this article on 11 Jun 2020 to correct the pdf so that it matched the webpage.
Remote diagnostic capability of aircraft special equipment
Authors: Abdukayumov A , Maturazov I S
Published: May 2020

The article presents the methods of remote diagnostics of special aircraft equipment. The methods of remote diagnostics used on aircraft are analyzed. Based on an analysis it is proposed to create a new method of remote diagnostics of special equipment of aircraft.

A post-publication change was made to this article on 11 Jun 2020 to correct the pdf so that it matched the webpage.
Diagram of plastic material transition into brittle state under hydrogen saturation
Authors: Mironov V I , Emel’yanov I G , Lukashuk O A
Published: May 2020

Major progress made in theoretically describing the behavior of a «hydrogen-metal» system still fails to unambiguously explain the phenomenon of hydrogen brittleness in metals. It follows that a phenomenological approach is appropriate to describe the transition of a plastic material into its brittle state with the growth of hydrogen concentration. A diagram for such a transition is plotted on the basis of known experimental data on how hydrogen affects mechanical properties of structural steels. It is intended for the purposes of predicting the behavior of fracture observed in elements of metal structures under peak overloads or normal operation.

A post-publication change was made to this article on 11 Jun 2020 to correct the pdf so that it matched the webpage.
Modeling of the thermal stresses in the welded rails of the continuous welded track in the permafrost zone
Authors: Fazilova Z , Loktev A , Shapran V , Chizhikov I
Published: May 2020

The article focuses on the numerical methods that are used to solve heat conduction nonlinear problems with the help of the h-matrix to account for the relaxation of thermal stresses in continuously welded rails. A general mathematical model on the basis of the heat conduction nonlinear equation is presented to calculate the thermal field in an infinite unlimited plate. The developed mathematical model can be applied to choose the implementation modes of the continuously welded rails into the optimal thermal mode.
Assessment of road pavement durability taking into account the variability of the traffic load parameters
Authors: Ermoshin N A , Bukatov D C , Filippov D A , Tsyba A C , Stroganov A V
Published: May 2020

The paper presents a methodology for calculating the influence of traffic load parameters on the durability of road pavement, such as elastic deflection, continuity of monolithic layers and shear resistance, the degree of influence of which depends on the reliability of the road in order to maintain the predicted characteristics of the traffic flow during the pavement inter-maintenance period. The developed methodology will allow for timely planning of measures for the maintenance and repair of road structures.

A post-publication change was made to this article on 11 Jun 2020 to correct the pdf so that it matched the webpage.
Remaining lifetime forecasting based on the dynamic simulation of used continuously welded rails
Authors: Loktev A , Fazilova Z
Published: May 2020

One of the basic principles of the modern track facilities policy is the maximum life extension of the permanent way elements less than 1,1 bln. tonnage. This policy allows to increase the competitiveness of the railway transport. The article is devoted to the research of the dynamic load impact on the target remaining lifetime of a continuously welded rail. The article also contains the results of the research that describe how some rail segments work under the load of different types, including pre-stress that develops under fastening the rail in the track and under the accumulation of the residual stress in operation.
Impact of damping on decay time of free oscillations in metal structures
Authors: Mironov V I , Ogorelkov D A , Lukashuk O A
Published: May 2020

The problem of increase of durability of the bearing thin walled metal structures of hoisting - and - transport machines maybe solved by means of structural damping which allows to increase the logarithmic decrement of the damped oscillations. In the work there are given the results of modelling and experimental check of the advantages of usage low-modulus foam materials as fillers at a structural damping of thin walled elements of metal structures. With the help of computational package SolidWorks there was conducted a numerical study to define amplitude-frequency characteristic of laboratory machine and then there were run the tests of model structure with building vibrorecord. As a result if research there was revealed a significant increase of the logarithmic decrement and reduction of the time of decay of natural oscillation of the foamed structure. Consequently, there are shown the advantages of the further researches to use energy-intensive foam materials to dampen the elements of the structures of handling machinery.
Daily strength testing of the Portland cement mortars
Authors: Tararushkin E V , Shchelokova T N
Published: May 2020

The study of daily tests (1-28 days) for compressive and flexural strength of cement mortars is presented in the article. The mortars were made from ordinary Portland cement, two different classes of cement were considered. Graphs with daily test strengths were obtained from the results of the experiment and the test results were fitted by exponential curves. To estimate the strength rates of mortars, numerical derivatives are calculated from experimental data and the exponential curves are fitted by the obtained values of numerical differentiation. As a result of experimental data processing, it was found that the flexural strength rate decreases to zero on the 12-14th day hardening of mortars, which can be explained by the end of the formation of macroporosity (voids) of the cement paste and the end of the chemical-physical processes of the formation of most contacts between the cement paste and the aggregate (sand grains).
Spectrum analysis of optical signals using sequential heterodyning
Authors: Moskaletz O D , Vaganov M A , Suedov E P
Published: May 2020

The possibility of transferring the idea of radio-frequency sequential heterodyne spectrum analysis to the optical range is considered. The question of a panoramic optical local oscillator in the form of a tunable laser is considered, where the consideration of stochastic phenomena is presented in the form of the sum of oscillations with a linear change in the instantaneous frequency and the stochastic component as interference. In this regard, it is proposed to use the technique of compression of radar signals to reduce the influence of the stochastic component of the oscillations of the laser panoramic local oscillator.
Asymptotic method for predicting the resonance during the descent of an asymmetric probe in the Martian atmosphere
Authors: Lyubimov V V
Published: May 2020

This work is devoted to the study of the uncontrolled descent of a probe with small asymmetries in the atmosphere of Mars. The aim of the work is to formulate a method for predicting the principal resonance in the problem of the descent of a space probe with small geometric and aerodynamic asymmetries in the atmosphere of Mars. The noted resonance is observed in the case of a long-term coincidence of two characteristic frequencies of a nonlinear system of equations simulating the motion of the probe relative to the center of mass. The applying of the averaging method makes it possible to analyze non-resonant evolutions in the angular velocity and spatial angle of attack caused by the influence of the principal resonance. Presented resonance prediction method can find application in a whole class of problems of modern astronautics.
Analysis of frequency characteristics of a structure with single modal reservation before and after failure
Authors: Medvedev A V , Zhechev Y S
Published: May 2020

The paper considers reservation structure implemented by using modal filtering. Such reservation is called modal reservation (MR) for short. To ensure certainty, we took a PCB layout with a single MR. It is shown that in quasi-static simulation, for the structure with losses in conductors and dielectrics, the cut-off frequency for an OC and an SC at one end of the passive conductor is 5.5 and 1.6 %, respectively, lower than for the circuit in operating condition, and the resonance frequencies are 8 and 11.6 %, respectively, lower. In electrodynamic simulation, for the conductor-loss structure and dielectrics, the cut-off frequency for an OC and an SC at one end of the passive conductor is 1.3 and 2.7 %, respectively, lower than for the circuit in operating condition, and the resonance frequencies are 7.3 and 10.65 % lower. The differences of resonance frequencies (f
0), cut-off frequencies (f
cu) in quasi-static and electrodynamic simulations are no more than 5.66 and 1.6 %, respectively.
Temperature influence on dynamic behavior of spacecraft waveguides
Authors: Kudryavtsev I V , Brungardt M V , Troshin S I , Kolotov A V , Mityaev A E
Published: May 2020

The lowest eigenfrequency and critical force are important parameters which defines structure behavior under dynamic loading. The paper describes the influence of temperature on the lowest eigenfrequency and critical force of a waveguide straight section in the spacecraft. The straight waveguide modeled according to the beam theory. It has been shown that the temperature change is equivalent an appearance and action of the axial force which makes the structure prestressed and significantly modifies its lowest eigenfrequency. An example of calculation of dependence of the waveguide straight section lowest eigenfrequency on temperature was considered, and it showed the existence of a critical temperature value, where the vibration frequency equals to zero. This critical temperature value corresponds to the loss of waveguide structure stability which is extremely undesirable and requires special methods to avoid such a situation. Stress state of waveguide in case of its loss of stability is also estimated.
Assessment of cyclic crack resistance of surface hardened parts
Authors: Kravchenko G N , Kravchenko K G
Published: May 2020

Calculation and experimental methods for evaluating the cyclic crack resistance of materials and plain workpieces after hardening their surface layer by various technological processes are presented and argued. These methods can be used in engineering calculations to determine and designate the most effective processes for surface hardening of parts from high-strength materials and to optimize process parameters.
Conceptual functional design of hybrid energy source of unmanned convertiplane
Authors: Nabiyev R N , Hazarkhanov A T , Garayev G I , Abdullayev A A
Published: May 2020

Convertiplane is explored in this article as an unmanned aerial vehicle incorporating hybrid power sources and hybrid propulsion systems. Based on the use of an electric generator in conjunction with a battery, fuel element and internal combustion engine as a source of energy in the non-manifold electrical engine convertiplanes, hybrid power sources and hybrid propulsion systems manufacturing specifications, as well as providing convertiplane with a long-term flight issues are considered hereby. In order to provide selection of the optimal design, hybrid energy source models from connection designs of different types of energy sources have been analyzed. Structural schemes of power systems with different configurations consisting of “sequential”, “parallel” and “mixed” connections of hybrid energy sources and hybrid propulsion systems have been analyzed and optimal connection schemes have been determined on their basis. It has been shown that when using four hybrid winged-motor group, the lifting system becomes complicated, the weight of the convertiplane is becoming relatively heavy. For an airplane weighing 15-20 kg, it is recommended to use four electric motors as a lifting engine, an internal combustion engine as a driving motor and an electric generator to charge the battery during the flight in order to ensure vertical flight, endurance or hovering at the height. A conceptual block diagram of a convertiplane type unmanned aerial vehicle is developed.
Physical and mechanical properties of materials of life vests for people with disabilities
Authors: Grigorieva Z R , Solodushenkova T S , Budeeva O N
Published: May 2020

The main requirements for life vests (buoyancy, durability, light weight, resistance to sea water and petrochemicals etc.) are met due to the right choice of materials for the outer parts of the articles. The current article presents some findings of the research into the main physical and mechanical properties of materials for outer parts of life vests designed for physically challenged people. On the basis of the research the authors have grounded the selection of materials to meet the requirements of the existing regulatory and technical documentation for the production of textiles of the relevant range.
Features of microscopic and macroscopic analysis of 35HGSL steel
Authors: Skryabin M L , Kuklin S M
Published: May 2020

Foundry steels are widely used in modern engineering today. But it is foundry steels that have the greatest number of defects, which can be detected by macro-and microanalysis. In addition, with the help of these studies, you can get an idea about the General structure of the metal and the presence of certain specific defects in it – stone-like and naphthalene fractures. Using microanalysis methods, it is also possible to evaluate the properties of multiphase alloys and cast iron, for which there are special scales that classify graphite and phosphide eutectic by shape and quantity. The article describes the features of conducting these studies using optical microscopy.
The study of magnetic resistance on thin single-crystal nickel films
Authors: Urinov Kh O , Amonov A K , Makhmudov F Dj , Urinova Z Kh , Shermatov B N
Published: May 2020

In this work the anisotropy of the transverse magnetoresistance of single-crystal nickel films was studied. The measurements were carried out on samples whose surface plane coincided with the [001] plane. Studies of magnetoresistance in a single-crystal nickel film showed the influence of tensile stresses acting on it from the side of magnesium oxide. The modification of the anisotropy of the magnetoconductivity of the film on the substrate as compared with the free sample is apparently associated with a change in the shape of the Fermi surface of the carriers.
Monitoring the technical and technological state of electric power complex facilities
Authors: Gibadullin A A , Erygin Yu V , Polyakov A E , Pobyvaev S A
Published: May 2020

The presented study is devoted to monitoring the technical and technological state of electric power complex facilities. As part of the study, the basic principles of monitoring and examining the state of equipment were analyzed, the process and procedure for monitoring the status of equipment and structures of the electric power complex were examined. The work analyzed the periods of preparation for the heating season of the Russian electric power industry, as a result of which it was revealed that the number of violations at electric power facilities was increasing, and the equipment of the federal districts was not fully prepared for the heating season by the readiness index. The work revealed that for almost all indicators of heat supply, water supply and sanitation, the number of violations and incidents during the heating period is increasing. At the end of the study, measures were presented that will ensure the stability and reliability of energy supply to consumers.
The effect of femtosecond laser treatment on the tribological properties of titanium nitride
Authors: Gazizova M Yu , Smirnov N A , Kudrayshov S I , Shugurov V V
Published: May 2020

The influence of femtosecond laser (fs-laser) processing on the structural-phase state of titanium nitride (TiN) coatings have been studied. It has been revealed using scanning electron microscopy and scanning probe microscopy that laser-induced periodic surface structures (LIPSS, LSFL) form on TiN coating surfaces. Depending on the laser scanning direction, two types of surface structures - parallel and cross-like ones have been obtained. Tribological tests showed that cross-like structures demonstrates better wear resistance properties in a dry friction, while parallel ones in a friction with lubricants.
Information and computing maintenance for the regional satellite operational monitoring system
Authors: Yakubailik O E , Pavlichenko E A , Romas’ko V Y
Published: May 2020

The article discusses the experience of supporting a regional operational satellite monitoring system. Based on NASA IOPP free & open source software, a set of programs has been created to automate the reception and automated processing of incoming satellite information. The development is primarily focused on data coming from the satellite receiving station, however, it also deals with the interpretation of data received via the Internet. A three-stage scheme of distributed processing and data conversion is implemented. The output goes to the local satellite data storage. A collection of specialized multi-channel raster images is also being formed for quick visualization of images in a geographic information web system. The current version of the system performs processing from eight different sensors installed on several satellites.
Residual stresses in Ti6Al4V alloy after surface texturing by femtosecond laser pulses
Authors: Zhidkov M V , Smirnov N A , Chen J , Kudryashov S I , Goncharov I Y
Published: May 2020

Surface topography and residual stresses in surface layers of α + β titanium alloy Ti6Al4V textured by 1030-nm, 320-fs-laser pulses were studied by scanning electron microscopy and X-ray diffraction analysis. It was found that multipulse laser processing leads to the formation of laser-induced periodic surface structures (LIPSS) on the surface of Ti6Al4V alloy. XRD studies showed that depending on the laser pulse fluence, both tensile and compressive residual stresses are formed in thin near-surface layers.
Simulation and histogram modeling of conveyor systems
Authors: Guzha E D , Romanenko V A , Skorokhod M A
Published: May 2020

Using the example of transport conveyor systems, an approach that reduces the cost of resources and time for the development and application of a computer simulation model during the design of the system, which provides a combination of simulation with the method of histogram calculations, which is one of the numerical methods for working with random variables, is proposed. The approach involves replacing a unified simulation model of a system with a complex of submodels of its components, accumulating intermediate results on the basis of submodels and subsequent histogram processing of these results in order to determine the probabilistic characteristics and performance indicators of the system. An example of a histogram simulation of an airport baggage handling system is presented.
Base error for centerless grinding of spherical rolling elements
Authors: Reshetnikova O P , Iznairov B M , Vasin A N , Belousova N V , Panfilova A V
Published: May 2020

The article considers a method for centerless grinding of spherical blanks. The scheme is implemented due to the presence of a trapezoidal helical groove on the driving wheel. The schematic diagram of the proposed method largely corresponds to the traditional centerless grinding scheme, which allows the use of machine tools available in production. It is shown that in the case of centerless grinding of balls, there is an error of basing on the operational size, namely, the diameter of the spherical surface. The adjustment size is mathematically determined when performing the technological operation of centerless grinding of balls, as well as the error of the adjustment size.
Mathematical model for changing the surface roughness of aluminum alloys when changing the final treatment modes
Authors: Galkin M G , Smagin A S , Poupyreva A S
Published: May 2020

In the process of multivariate design of machining technology, one of the important tasks is the selection of optimal cutting conditions at the final transitions of the shaping process, ensuring a given surface quality on a workpiece made of the corresponding material. At the same time, to describe the majority of design procedures for the machining process, there are problems associated with the algorithm for choosing a solution method, response function, and areas of feasible solutions at all stages of processing. In this paper, as an algorithm for solving the problem, it is proposed to use the well-known technique of extreme experimental design, which allows to obtain a mathematical model of the investigated multifactor process with incomplete knowledge of its optimization mechanism. Such a study allows us to simplify the procedure for setting the processing regime of the workpiece at the final stage in the conditions of the existing production, while ensuring the specified quality of the machined surfaces and maintaining the productivity of the forming process. This technique is the subject of consideration in this work.
Improving the quality of tightened joints of metal-cutting machines
Authors: Lipov A V , Kochetkov D V , Bolshakov G S
Published: May 2020

Tightened joints using threaded assembly are widely used in modern metal cutting machines. Reliable operation of such joints is determined by the value of the required initial tightening and its stability during operation of the machines. It has been established that the cause of the weakening of the thread in joints is their self-loosening at significant relative lateral displacements of the fastened parts, at which the screw tilts with slipping in the thread and along the supporting surface of its head. The self-loosening in the bolted joint of the wedge adjusting devices regulating the rolling of the multi-purpose machines of the drilling-milling-boring group, loaded with an inertial load, which reduces their geometric accuracy, is considered. A model has been developed for the process of creating an interference fit and the conditions under which the screws of adjusting devices are unscrewed are determined. Measures have been developed to determine the rational parameters of screws and their tightening values, ensuring its stability during the operation of the machines.
The combination feeder of a continuous-action loader for the bulk load
Authors: Khakimzyanov Rustam R , Mashtakov Alexander P
Published: May 2020

The spectrum of construction, industrial, agricultural and other bulk load includes a lot of names that vary in their physical, mechanical and volume-mass characteristics. Continuous-action loaders are developed and constantly improved for bulk load shipping. Their main operating element, which is responsible for the efficiency and power consumption of the drive, is a feeder. The feeder separates or grabs the load from the surface on which the bulk load is stored. It is proposed to use a combination feeder consisting of two operating elements, that will allow to grab the load and transport it simultaneously. The kinematic analysis of the feeder operation and its interaction with the load has been carried out. We have derived the parametric equations of the blade motion when the loader is traveling and the shaft is rotating in the coordinate form. Relying on the length of the blade trajectory, it is presented the expression for the determination of the continuous-action loader with the combination feeder efficiency. The efficiency depends on the physical and mechanical properties of the load, operational and design specifications of the feeder.
Refinement of the procedure to determine durability of abrasive materials
Authors: Pushkarev O , Bagaiskov Yu
Published: May 2020

Material performance as well as its purpose and way of use depend on its physical and mechanical properties. The Shlif device based on a small-sized friction machine was used to test durability of abrasive materials. The conditions and procedure of such studies were refined. Boron carbide with grain size F 80, sample weight of 0.04 g, specific sample load of 0.01 MPa was used as an abrasive body. According to the test results of the samples, the wear time is 5 minutes. Since the results of studying the sample wear are sensitive to process factors and tool parameters, and there is a correlation relationship with the field test results, the results can be used for rapid quality analysis of abrasive tools in the process of production and operation, as well as for designing of new types of tools.
Applications of fatigue gauges for detection of subsurface cracks and defects
Authors: Tyutrin S G
Published: May 2020

The possibility of using fatigue gauges to detect cracks and crack-like defects that occur at some depth in the specimens was investigated. Industrial tin foil with additional annealing was used. Subsurface cracks were modeled by cross drilling followed by cutting with steel wire. The distribution of appearing stresses under the action of static load was estimated by the finite element method. In the presence of a subsurface crack, the first manifestations of fatigue damage on the gauge surface are observed in two zones located from the dangerous section at a distance approximately equal to the depth of the crack. This allows not only to diagnose the presence of cracks and similar defects, but also to determine the distance from the top of the crack to the surface of the specimen.