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

2021

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

AN INVESTIGATION OF OPTICAL AND ELECTRICAL PROPERTIES OF THE TlGaSe 2 SINGLE CRYSTAL

Posted in 2021, Issue № 12 (114) December 2021, PHYSICS AND MATHEMATICS | 0 comments

In order to determine the nature of optical transitions, the authors conducted studies in the self-absorption edge of TlGaSe 2; transmission and reflection were measured at 300 K and 77 K, the authors also calculated the absorption coefficient. The results are in good agreement with the calculations of the Brillouin zone. It is shown that the long-wave edge of the proper absorption band is formed by indirect transitions (Y→D). At 4.2 K in the spectrum, an intense absorption line λ = 579.5 nm (2,138 eV) is observed in the absorption spectrum. It can be concluded that in TlGaSe 2, the self-absorption edge is formed by a direct exciton transition, which is preceded by an indirect optical transition. Studies of transitions corresponding to the TlGaSe 2self-absorption edge show that the edge is formed by a transition between extreme points of the Brillouin zone that have polarization features. Transitions occur from several levels located in close proximity to each other. TlGaSe 2 crystallizes in a monoclinic structure with the Cc space-group, which indicates that these crystals have a single element of symmetry – the reflection plane σ perpendicular to the layers. However, the experimental results obtained are not explained by this symmetry of the crystal.

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NUMERICAL SIMULATION OF LAVA FLOWS IN MODELS OF ISOTHERMAL VISCOUS MULTIPHASE INCOMPRESSIBLE FLUID

Posted in 2021, Issue № 12 (114) December 2021, PHYSICS AND MATHEMATICS | 0 comments

A lava flow begins to form when molten rock erupts onto the surface of the Earth and slowly spreads to the surface from a fissure vent. Eruptions create different lava flows (for example, flows of a different structure and flow velocity) under the influence of gravity, depending on the chemical composition, temperature of igneous rocks, and the topography of the surface over which the lava flows. Despite the fact that volcanic lava flows do not have a significant impact on people’s lives, their danger is considerable, since hot lava kills vegetation, destroys infrastructure, and can cause flooding due to melting snow/ice. Following the development of computing resources, numerical modeling of lava flows over the past few decades has moved from modeling one-dimensional flows to modeling three-dimensional flows, which is most adequately able to reflect real natural processes. In order to investigate the dynamics and interaction of lava flows, the current article develops three-dimensional numerical models of flows of an isothermal viscous Newtonian multiphase fluid on various surfaces under the influence of gravity. A complete simulation of a lava flow is a challenging task from a physical, mathematical, and numerical point of view. The mathematical model includes the Navier-Stokes equation, the incompressibility equation, and the phase transfer equations with corresponding initial and boundary conditions. The finite volume method is used for numerical approximation of the mathematical model. The program codes are implemented in the ANSYS Fluent package in C. When conducting numerical experiments, a parallel-acting computer was used. The article demonstrates the results of calculations of the model experiment. Lava flow reconstruction models can provide significant assistance in the design of barriers reflecting lava flows. The availability of technological and scientific data (such as satellite monitoring data, high-speed calculation algorithms, and realistic models) will allow for integrating data into models with traditional methods of studying volcanic activity, which will allow more efficient use of the results.

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AN ANALYSIS OF THE VARIATION OF QUANTITATIVE CHARACTERISTICS OF BLACKBERRIES (RUBUS L.) IN MOSCOW OBLAST

Posted in 2021, BIOLOGY, Issue № 12 (114) December 2021, БИОЛОГИЧЕСКИЕ НАУКИ | 0 comments

Blackberries are a product that is only gaining popularity in Russia due to their taste qualities and the presence of a wide range of biologically active substances in fruits. Therefore, the aim of the study was to study the degree of variation of quantitative characteristics and to identify the influence of the variety on them. The research, which was conducted in Moscow Oblast in 2021, examines 15 quantitative characteristics of the following blackberry varieties: Oauchita, Chester Thornless, Polar, Thornfree, Čačanska Bestrna. The paper highlights features with both a low coefficient of variation and a high degree of variability. The analysis of variance showed the presence of a significant influence of the variety on the length of the fruit (the share of the influence of the variety is 93%), the amount of sugars (98%), the average number of stone fruits per fruit (92%), the width of the central leaflet (74%), the number of fruits on the lateral (92%). The article also lists significant differences in varieties for a number of characteristics and indicates their average values.

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CONSTRUCTION OF PLATES FOR LINING IRRIGATION CHANNELS OF RECLAMATION SYSTEMS USING COMPOSITE REINFORCEMENT

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

The current article examines the possibility of replacing steel stressed reinforcement in reinforced concrete channel plates with composite fiberglass. Steel reinforcement in structures undergoes corrosion over time, loses properties, these circumstances lead to the loss of operational properties of structures. Composite reinforcement has a number of advantages over steel, but there are also negative properties, for example, the deformation of fiberglass is up to 2.8%, while metal is 25%. In this regard, the task of developing and testing by theoretical calculation of plate designs for lining irrigation channels of reclamation systems using non-metallic composite reinforcement as a stressed one can be considered urgent. The possibility of using non-metallic composite reinforcement as a working stressed reinforcement of a hollow-core slab is proved by example.

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MODIFICATION OF METHODS FOR OPTIMIZING THE MODES OF ELECTRICAL NETWORKS IN ORDER TO REDUCE POWER LOSSES FOR CORONA DISCHARGE

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

The article demonstrates the need to reduce corona discharge losses in electrical networks. To achieve this goal, the authors examine the statistical data of network companies, as well as the results of scientific research on this topic. As means of reducing losses, the study considers optimization of the modes of electrical networks. The authors describe the existing optimization methods and highlight their disadvantage, which is the lack of consideration of control actions implemented by FACTS devices. The study presents a modification of optimization methods with the goal of eliminating the omission of FACTS devices in the optimization problem. A mathematical model of the modified optimization method is also shown. The implemented method was tested on a computational model in Rastrwin3 and Matlab. Based on the results of a successful check, the study establishes the operability of the proposed modification of optimization methods.

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PREDICTIVE CALCULATION OF THE PHASE THICKNESS OF NITRIDED CASES

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

The current article conducts an analysis of the regularities of the nitriding processes in various media and experimentally determines the order of phase formation. The study determined a parameter that comprehensively characterizes the nitriding process, which was called the kinetic coefficient; the study also determines its temperature-time relationship. The authors propose a model for calculating the thicknesses of the phases of nitrided cases, including the presence of alloying elements in the steel. It is shown that the alloying elements have the same effect on the growth of the nitride layer and the α – solid solution at different methods of the process. This model can be used for any nitriding technologies if the presented kinetic coefficients are determined.

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INFORMATION AND MEASURING SYSTEM FOR CONTROLLING THE BREAD BAKING PROCESS

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

The article describes the technology underlying the system of control and automatic control of the baking process to regulate the intensity of coloring of the bread crust. The study uses a laboratory machine to register the change in the color of the crust of test products depending on the surface temperature. The experiments show that the color was instrumentally evaluated indirectly by determining the value of the reflectivity of the crust using photocells. To eliminate the influence of temperature, the photocells were placed in a thermostatic device. Calibration of the installation with a photometer made it possible to adjust the values issued by the photocell, taking into account its selectivity to visible spectrum radiation. The temperature of the test pieces was determined by thermocouples placed on their surface.

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A STUDY OF TECHNOLOGICAL MODES OF PRODUCTION OF BREAD AND PASTRY PRODUCTS

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

The article examines the methods of heating a dough piece when baking bakery and pastry (gingerbread) products in ovens with combined heating (infrared and high-frequency). The authors determine optimal technological characteristics (wavelength) of infrared radiation during the heating of test samples. Judging by the maximum depth of penetration of infrared radiation, the research concludes that the maximum intensification of the heating of the dough in furnaces occurs at a wavelength of ~1 nm. At the same time, the duration of baking pastry with the help of infrared emitters, compared with conventional baking with hot air, is reduced by 20-50% when baking cakes, pies and cookies, and by 30-40% when baking cupcakes.

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DEVELOPMENT AND ANALYSIS OF VIBRATION SENSORS BASED ON MAGNETIC FLUID

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

The current article introduces the designs of sensors based on magnetic fluid for diagnostics and monitoring of the vibration level of technical equipment for various purposes. Magnetic fluid vibration sensors have advantages over known designs, namely, they have high performance and reliability, ensure operability after exposure to significant loads and retain their performance characteristics for long periods of time. Based on the analysis of the developed structures, as well as numerical and experimental evaluation of the operational parameters of the sensors, the article also provides recommendations for their use. The novelty of all designs of magnetic fluid vibration sensors is confirmed by the presence of security documents.

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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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SYNTHESIS, INVESTIGATION OF THE STRUCTURE AND PROPERTIES OF COMPLEX COMPOUNDS OF HYDROXYL AMINO ACIDS WITH COPPER IONS

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

The research synthesizes new complex compounds based on copper ions and proteinogenic amino acids L-serine and L-threonine. The reactions were carried out by heating in solutions followed by washing and drying of the precipitated salts. The composition and structure of the obtained compounds were studied by IR spectroscopy, pH potentiometry, titrimetry, and spectrophotometry. The study shows that complexes are formed in a molar metal-ligand ratio of 1 : 2. The authors confirm bidentate coordination of copper by amino acids and N,O-chelation due to donor-acceptor bonds of the carboxyl and amino groups. The absorption bands characteristic of Cu-N, Cu-O bonds, and the displacement of the maxima of functional groups of amino acids are recorded in the IR spectra. The instability constants of threoninate and copper serinate are calculated.

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