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Submit scientific paper, scientific publications, International Research Journal | Meždunarodnyj naučno-issledovatel’skij žurnal

ISSN 2227-6017 (ONLINE), ISSN 2303-9868 (PRINT), DOI: 10.18454/IRJ.2227-6017
ЭЛ № ФС 77 - 80772, 16+

Featured articles

SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS OF POWDER NITRIDE-CARBIDE COMPOSITION TiN-SiC DURING COMBUSTION OF THE «Si-Ti-NaN3-(NH4)2SiF6-C» SYSTEM

Posted in 2021, ENGINEERING, Issue № 12 (114) December 2021 | 0 comments

The possibility of synthesis of a highly dispersed powder nitride-carbide composition TiN-SIC by burning a mixture of sodium azide (NaN3) with elemental powders of silicon (Si), titanium (Ti) and soot (C) and an activating additive – a halide salt of ammonium hexafluorosilicate ((NH4)2SiF6) in a nitrogen atmosphere is investigated. The combustion parameters, phase composition, morphology and particle sizes of the synthesized products were determined. It is shown that, after water washing, the powdery combustion product consists of titanium nitride (TiN), silicon carbide (β-SiC), silicon nitride of two modifications (α-Si3N4 and β-Si3N4), and an insignificant amount of free silicon (Si). In most cases, the resulting nitride-carbide composition TiN-SiC is a mixture of submicron (0.1-0.5 μm) equiaxed particles and fibers, promising for obtaining corresponding structural composite ceramic materials with improved mechanical properties at lower temperatures.

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MICROSTRUCTURE AND TRIBOTECHNICAL PROPERTIES OF MULTILAYER ION-PLASMA COATINGS CrN-TIN

Posted in 2021, ENGINEERING, Issue № 12 (114) December 2021 | 0 comments

The current article presents the results of a study of the structure and tribotechnical properties of multilayer nanostructured coatings made of alternating layers of CrN and TiN obtained by vacuum-arc plasma-assisted deposition of chromium nitride and titanium nitride at a temperature of 320 ¸390 0 C for C11000 grade copper and aged copper-beryllium alloy C17200. The study also conducts an analysis of the structure of coatings and their behavior during tribological tests.

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RESULTS OF THE STUDY OF OPTICAL CHARACTERISTICS OF SOOT PARTICLES AND PARAMETERS OF RADIATION HEAT EXCHANGE IN THE COMBUSTION CHAMBER OF A MARINE DIESEL ENGINE

Posted in 2021, ENGINEERING, Issue № 12 (114) December 2021 | 0 comments

Trends in the development of modern marine diesel engines are primarily associated with an increase in their specific power, improvement of efficiency parameters and environmental characteristics. This causes the appearance of a number of issues, the most important of which is the problem of thermal tension of the parts forming the combustion chamber. The high level of thermal loads of these parts of marine diesel engines is one of the main reasons for their reducing operational reliability. Errors in the calculated estimates of the thermal and stress-strain state of the combustion chamber parts at the design stage currently reach 30 – 80%. This makes it necessary to improve mathematical models describing the processes of heat exchange in the combustion chamber of marine diesel engines. The purpose of this article is to present and discuss the results of research on the optical characteristics of soot particles and radiation heat exchange in the combustion chamber of a marine diesel engine type 6 ChN 24/36 (6 ЧН 24/36). The study experimentally proves that soot particles formed in the combustion chamber of a marine diesel engine can be classified as small from an optical point of view. The average values of the local resultant radiation fluxes for the surfaces of the cylinder cover, piston, and piston boss for the duty cycle presented in the article make it possible to determine their value of variable temperature stresses at the design stage. This is very important for assessing the reliability of the combustion chamber parts in operation.

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JUSTIFICATION AND DEVELOPMENT OF A ROTARY DUST COLLECTOR FOR AIR PURIFICATION DURING POST-HARVEST PROCESSING OF GRAIN AND SEEDS

Posted in 2021, ENGINEERING, Issue № 12 (114) December 2021 | 0 comments

Russia has a huge experience in the development and operation of dust-collecting equipment. The Scientific Research Institute of Agriculture N. V. Rudnitsky North-East, Vyatka State Agricultural Academy and many other educational institutions have developed and put into production many dust-collecting devices used in post-harvest processing of grain and seeds. Despite the aforementioned results, this industry requires more detailed consideration and improvement. The purpose of this study is to develop a highly efficient rotary dust collector for air purification in grain and seed processing processes.

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THE METHOD OF MODELING THE STRUCTURAL STRENGTH OF A MATERIAL USING A SOLID-ROLLED RAILWAY WHEEL

Posted in 2021, ENGINEERING, Issue № 12 (114) December 2021 | 0 comments

The article describes one of the stages of the implementation of a computational and experimental methodology for assessing the structural strength of a material using a railway wagon wheel as an example. The author examines the features of numerical simulation of the stress-strain state of a railway car wheel with a pan-head disk shape. The boundary conditions for fixing and loading the wheel correspond to the movement of the car in a curved section of the track. The results of the analysis of finite element modeling of wheel deformation show a sufficiently high level of stress intensity in the rim zone from the outside of the wheel, while the type of stress-strain state is more “rigid” than in the elastic zone, which affects the resource of static and fatigue strength. The structural strength of the wheel material in the rim zone is analyzed on the basis of tests of a special laboratory sample. The results of the analysis show that the limiting value of the stress intensity in the rim zone of the wheel is about a quarter higher than the value of the tensile strength of the steel under study, determined under uniaxial tension.

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IDENTIFYING THE PROBABILISTIC LEVEL OF THE RISK OF AN ASH AND SLAG DUMP DAM ACCIDENT ACCORDING TO THE CONDITION OF SLOPE STABILITY AND AN APPROACH TO ASSIGNING SAFETY CRITERIA

Posted in 2021, ENGINEERING, Issue № 12 (114) December 2021 | 0 comments

The article provides a brief basis of a probabilistic methodology for determining the level of risk of possible accidents of hydraulic structures using the method of statistical modeling (Monte Carlo). The presented methodology was applied to the assessment of the risk of possible accidents of one of the multi-layered ash and slag dumps of an Experimental thermal power plant located in Rostov Oblast, Russian Federation. Based on the results of surveys carried out during the design and subsequent operation of the ash dump, as well as data from field observations of the position of the depression surface of wastewater, the study conducts risk assessments of a possible collapse of the slope of the ash dump dam for various cases of load combinations and compares the obtained values of the accident risk level with permissible regulatory risk values and reliability coefficients of the limit state method obtained in accordance with current standards.

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APPLICATION OF ARTIFICIAL INTELLIGENCE FOR MEDICAL IMAGING

Posted in 2021, ENGINEERING, Issue № 12 (114) December 2021 | 0 comments

The article reviews modern research in the field of medical imaging using artificial intelligence, in particular for the diagnosis of the cardiovascular system. The article notes the relevance of the research and examines research on existing methods of visualization of the cardiovascular system using artificial intelligence. The authors analyze the subject of modern research and emphasize the increasing influence of modern mobile technologies that allow for removing and transferring data to a remote expert for diagnosis. The study describes research works on the introduction of an artificial neural network in medical imaging, the stages of deep learning in the field of radiology. Also, the authors present research on the technical aspects of the use of three-dimensional printing in the treatment of heart diseases, as well as on the use of virtual reality in the study of the anatomy of the heart.

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ANTIOXIDANTS OF THE LEAVES OF AMELANCHIER ROTUNDIFOLIA

Posted in 2021, Issue № 12 (114) December 2021, PHARMACEUTICS | 0 comments

The article features a comparative study of the spring and autumn leaves of Amelanchier rotundifolia for the total amount of antioxidants, including phenolic compounds and flavonoids. The content of antioxidants was determined by the amperometric method on a liquid chromatograph “Tsvet Yauza-01-AA”. The total content of phenolic compounds was determined using the Folin-Chocalteu reagent, while the content of flavonoids was determined via differential spectrophotometry. It was found that the optimal extractant for extracting all antioxidants from the analyzed raw materials is ethyl alcohol, 50%. The greatest amount of antioxidants, phenolic compounds, and flavonoids accumulates in spring leaves. Moreover, there is a clear correlation between the total content of antioxidants, phenols, and flavonoids.

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A COMPARATIVE ANALYSIS OF DRINKING WATER IN THE CITY OF KOKSHETAU, AKMOLA REGION

Posted in 2021, CHEMISTRY, Issue № 12 (114) December 2021 | 0 comments

Mineral waters are natural groundwater formed in the thickness of the Earth’s crust with certain geological, structural, geothermal, hydrogeological and geochemical conditions that determine the patterns of their spatial localization, gas, ion-salt and trace element composition, temperature and other indicators. In the course of the study, the authors examine the issues of studying the chemical composition of waters from water sources located on the territory of Kokshetau and used in the production of mineral waters such as “Kulager-Arasan”, “Svezhest”, “Turan”. The study determines the content of chloride ions, sulfate ions, magnesium cations, calcium, sodium, and bicarbonates and conducts a comparative analysis of the content of chemicals and organoleptic characteristics.

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SYNTHESIS OF N – HETEROCYCLIC PROLIGANDS AS PROMISING NEW GENERATION OF STABILIZING LIGANDS

Posted in 2021, CHEMISTRY, Issue № 12 (114) December 2021 | 0 comments

The paper analyzes the use of organometallic catalysts, namely the complexes with N-heterocyclic carbenes. The substrates under study can be used as stabilizing ligands for the synthesis of stable complexes. In turn, the complexes can be used as effective catalysts of a new generation of carbon-carbon, carbon-heteroatom bond formation. In most cases, the activity of catalysts directly depends on the structure of N-heterocyclic carbenes in terms of steric and electronic properties, which is of the greatest interest as objects for research. The methods presented in this study allow for obtaining both symmetric and asymmetric benzimidazole, imidazole, and triazole carbenes.

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