bluuebunny/crossref_metadata_2025 huggingface dataset:
DESIGN CALCULATION TECHNIQUE FOR THICK-WALLED COMPOSITE CONSTRUCTIONS OPERATING UNDER HIGH-SPEED LOADING
Authors: BABAYTSEV A. V. , RABINSKIY L. N.
Published: August 2021

The scientific paper presents a technique for calculating a thick-walled axially symmetrical construction consisting of a steel rod (reinforcing component) and an external thick-walled shell made of carbon fiber. The construction is loaded with linear load distributed along its length, associated with the operating external pressure, and inertial forces. The technique is based on a one-dimensional model of a composite rod of variable cross-section, roughly taking into account transverse deformations, which is necessary when analyzing a thickwalled construction operating under pressure. In the proposed approach, the geometry of the product is divided into sections and approximated by fragments in the form of truncated cones and, in the particular case, in the form of cylinders. As a result of calculations, the distribution of normal tensile/compression stresses in the shell and in the reinforcing rod, as well as tangential stresses at the boundary of their contact, are determined. As a result of test calculations, a fairly good consistency of the considered one-dimensional model with refined finiteelement modeling is shown. It has been established that the concentration of shear stresses is realised due to the presence of substantially inhomogeneous deformations in the areas of sharp changes in geometry, a reduction in the radius of the shell (the appearance of edge effects), and in the area of a sharp increase in the radius of the bevel of the shell where external pressure is in place.
EVALUATION OF HARDENING EFFICIENCY WITH CONVECTIVE HEAT AND MASS TRANSFER MECHANISM DURING LASER SURFACE ALLOYING IN REFLOW MODE
Authors: BELASHOVA I. S. , RABINSKI L. N. , TURSHAVINA O. V.
Published: August 2021

The modern stage of equipment development imposes increased requirements for the performance characteristics of parts. Different components and parts of machines, metal-cutting tools and metal structural elements work in the conditions of high friction, high specific loads, high temperatures, a wide range of speeds and impact of aggressive media, for instance. Therefore, improvement the quality, reliability, economical efficiency and productivity of machines, tools, equipment and other engineering products as well as reduction of their specific material consumption and energy consumption is achieved primarily by the use of materials and progressive strengthening technology that improve the hardening, wear resistance, corrosion resistance and other physical and mechanical properties of machine parts and tool. Therefore, the main objective of the paper was to evaluate the mass-transfer during laser surface alloying in the reflow mode. To evaluate the effectiveness of surface hardening technology, it was proposed to use two new parameters – reduced wear and reduced integrated micro hardness of the modified surface layer. Based on an analysis of the experimental data on the wear of a cutter made of HVG and U10 steel, processed by a laser with smears in the reflow mode, the existence of a correlation between the entered parameters is demonstrate and the regression equation is obtained. The proposed approach to evaluating the effectiveness of surface hardening can be used not only in the special case of laser modification but also for any other technology for creating gradient and functional coatings.
ORIGINATION AND PROPAGATION OF TEMPERATURE SOLITONS WITH WAVE HEAT TRANSFER IN THE BOUNDED AREA DURING ADDITIVE TECHNOLOGICAL PROCESSES
Authors: FORMALEV V. F. , KOLESNIK S. A. , KUZNETSOVA E. L. , RABINSKIY L. N.
Published: August 2021

Within this work, based on analyses of problems on wave heat transfer in bounded bodies, the theory of thermally isolated waves (solitons) is developed to investigate the heat transfer processes in the initial time vicinity and in the vicinity of the bounded body, that is the time scales are commensurate with the relaxation time (nanoseconds), and the scales of the spatial variable are measured in nanometers. A new analytical solution of the wave heat transfer based on the heat conduction equation of hyperbolic type under the action of a series of solitons was received, based on which the interaction of individual solitons with each other, absorption and reflection of the solitons from the body boundaries was analyzed. Analysis of a large number of results made clear that thermal solitons reflect not as mechanical ones, since first there is absorption of the soliton thermal energy by the heat-insulated boundary on the heat-insulated walls, and then the energy is rejected by the thermal conductivity in the opposite direction. It was found that the temperature gradient inside the soliton is negative in the forward direction and positive in the reflected direction. The results of the paper can be used in thermal interaction of high-power radiation with solid surfaces, as well as in the problems of quantum mechanics.
STRUCTURAL CHARACTERIZATION OF 2-AMINO-2-OXOACETIC ACID BY X-RAY POWDER DIFFRACTION AND QUANTUM CHEMISTRY
Authors: DELGADO G. E. , BELANDRIA L. M. , GUILLEN M. , MORA A.. J. , SEIJAS L. E.
Published: August 2021

2-amino-2-oxoacetic acid, carbamoyl formic acid, or oxamic acid is an active pharmaceutical ingredient (API) of great importance mainly because is an inhibitor of lactic dehydrogenase (LDH). It acts as an inhibitor to the metabolic pathways of the tumor cells and exhibited significant anticancer activity against nasopharyngeal carcinoma (NPC) cells in vitro and can be considered as a potential drug for the treatment of type 2 diabetes. Also, this compound could be used as a building block in the design of supramolecular architectures based on hydrogen bonds through the complimentary hydrogen-bond functionalities of the carbonyl and amide functional groups present. Single-crystal X-ray diffraction is the most powerful technique for crystal structure determination of small molecules. However, for several materials, including oxamic acid, it could be complicated to grow single crystals of suitable size and quality that make them appropriated to structure analysis. For this reason, the structural study was conducted with powder X-ray diffraction which is a process significantly more challenging than structure determination from single-crystal data. Oxamic acid has been characterized by FT-IR and NMR spectroscopic techniques, thermal TGA-DSC analysis, semi-empirical PM7 calculations, and X-ray powder diffraction. The title compound crystallizes in the monoclinic system with space group Cc, Z=4, and unit cell parameters a= 9.4994(4) Å, b= 5.4380(2) Å, c= 6.8636(3) Å, b= 107.149(2)°, V= 338.79(2) Å3. The molecule has a trans conformation. The molecular structure and crystal packing are stabilized mainly by intra- and intermolecular O--H···O and N--H···O hydrogen bonds. The structural characterization of this type of API compound is important to understand its mechanisms of action due to its considerable biological effects. In particular, for oxamic acid, this structural study would allow subsequent examination of its medicinal properties as an antitumor and antidiabetic agent.
X-RAY POWDER DIFFRACTION DATA FOR A NEW PIRAZOLINE COMPOUND
Authors: DELGADO G E , DELGADO-NIÑO P , LOBATON R , LIEW S-M , JAMALIS J
Published: August 2021

Pyrazolines are important agents in medicinal chemistry as a promising scaffold for structural modification and drug development studies due to their wide range of biological activities such as anticancer, antifungal, antibacterial, antidepressant, anticonvulsant, antitubercular, antioxidant, antileishmanial and antiinflammatory activity. These heterocyclic compounds can be prepared by refluxing chalcone with hydrazine hydrate and anhydrous sodium acetate in the presence of glacial acetic acid. The structural characterization, molecular and crystalline structure, of these organic compounds, allows studying their biological properties to know their potential applications. Hence the use of XRPD is very important because it allows obtaining a record to be used as a method of identification. The aim of this investigation was to obtain and reported good quality Xray powder diffraction data the pyrazoline compound 1-(3-(4-iodophenyl)-5-(3-methyl thiophen-2-yl)-4,5-dihydro-1H-pyrazol-1-yl)ethan-1-one, which could be used as potential anti-microbial and anti-cancer agent. The powder pattern was indexed in the monoclinic space group I2/a with unit cell parameters a = 25.440(5) Å, b = 5.124(2) Å, c = 26.261(6) Å, b = 105.75(2)° and figures of merit M20= 38.2 and F20= 66.6 (0.00573, 53). All measured lines were indexed and are consistent with the monoclinic space group. The powder pattern will be included in the Powder Diffraction File database to be used as a reference.
USING ARTIFICIAL NEURAL NETWORKS FOR TIME DIFFERENCE OF ARRIVAL TARGET LOCALIZATION BASED ON REDUCED DISCRETE COSINE TRANSFORM
Authors: SHEVGUNOV T.
Published: August 2021

The angular coordinates of the pulse source are determined by comparing the signals received simultaneously on several channels. To solve this issue, the application of neural networks is highly important. In this article, the application of the artificial neural network (ANN) approach to the task of target localization is discussed. The research was performed on the basis of a feature extraction technique executed by a discrete cosine transform, which allowed to obtain a compact representation of the signal energy subjected to digital processing. The author defines the angle-of-arrival estimation scheme based on time difference of arrival estimators and the particular problem of estimating constant delays as informative parameters embedded into received signals that are noisy and damped copies of the reference signal. The adaptive element framework is used for synthesis of the feedforward ANN which is fed with the reduced set of the most sensitive discrete cosine transform (DCT) coefficients, which provide a concise representation of the first-order cyclostationary random process. The investigation on the delay estimation accuracy has been carried out to evaluate the performance of the ANNs with different size of their hidden layer and various numbers of the DCT coefficients at their input. It has been proved that five DCT coefficients are enough for the discrimination of the phase shift in the whole range. In turn, it results in the reliable delay estimation produced by the trained ANN that contains eight neurons in its hidden layer.
SPECTRAL APPROACH TO THE ESTIMATION OF THE TIME SERIES OF THE POWER CHANGE IN THE SUBSTATION METERING UNITS AND ITS APPLICATION IN THE CONTROL MODES OF SUBSTATION ELECTRICITY METERING SYSTEMS
Authors: PICHUGIN Vladimir N. , YAGIN E. V. , LUKISHIN A. V. , PAKHOMOVA O. A. , HAZOV A. Y.
Published: August 2021

In order to create models of extended surfaces in the long and short wavelength parts of the wave spectrum, it is necessary to know the dispersion characteristics of tape-like obstacles perfectly located both in free space and on an extended surface. Methods of remote studying of extended surfaces, based on an analysis of signals that are generated by reflection or radiation of electromagnetic waves passing neoplasms allows us to view the topography, characteristics, and type of the different locations, sizes of various objects. One of the effective methods of study is to solve the problem of diffraction of electromagnetic waves on an infinitely extended object in free space. The purpose of this study is characteristics of electromagnetic waves during diffraction of electromagnetic waves at objects that can be used as radar systems. The method of statistical processing of experimental data from field tests and mathematical description of electromagnetic radar situation, as well as its computer simulation were used. The result of this study can be formulated as the development of analytical and software methods for analyzing diffraction pattern of electromagnetic waves in multi-wave mode of reception on infinitely extended object in free space, as well as a software method for calculating diffraction characteristics at frequencies exceeding the basic frequency, taking into account the inhomogeneity of electromagnetic fields in these conditions. The practical significance is the research results used in the development of a universal technique for design and development of radar systems capable of working adequately in conditions of electromagnetic environment in question. The results of this research will allow a complete description of the electrodynamic picture of wave propagation and its diffraction, namely, taking into account the diffraction properties of radar systems will allow us to develop a direction for their wider production and distribution.
POSSIBILITY TO INCREASE THE CHI-SQUARE TEST POWER ON SMALL SAMPLES BY MEANS OF TRANSITION TOWARDS ANALYZING OF IT’S DISCRETE SPECTRUM
Authors: VOLCHIKHIN V. , IVANOV A. , GAZIN A.
Published: August 2021

The purpose of the work is to increase the chi-square test power by analyzing the spectrum of output states of this test discrete form. The refusal from a hypothesis of a spectrum continuity of a chi-square molecule output states allows you to observe 22 spectral lines of different probability amplitudes on a sample of 11 experiments. It is proposed to obtain a mode of support for the quantum superposition of the output states of the chi-square molecule through the random selection of 11 experiments from the general population of 21 experiments. This makes it possible to obtain about 200,000 different states of the molecule, which is quite sufficient to estimate the 8-level states of the probability amplitude of 22 output spectral lines. In the case of the histogram with 6 intervals, the hypothesis of a continuous spectrum of the chi-square test for a sample of 11 experiments does not allow us to distinguish between normal and uniform laws of data distribution with a confidence probability acceptable for practice. The situation changes dramatically if the spectrum discrete nature of the chi-square molecule states is taken into account. It is possible to obtain significantly different digital portraits of the normal and uniform data distribution. Their differences are about 40 bits as per the Hamming distance. The chi-square molecule can be interpreted as a certain square neuron with a Gammerstein structure. Simulation of Schrödinger equations on an ordinary computer has exponential computational complexity in relation to the number of electrons (degrees of freedom or experiments). For this reason, the reproduction of quantum computations on 22 qubits and more within the framework of quantum mechanics on an ordinary computer is technically difficult to perform. A completely different situation arises with the support of quantum superposition of the chi-square molecule. The support of quantum superposition of the chi-square molecule has linear computational complexity. As a consequence, it is possible to implement 22-qubit, 222-qubit, 2222-qubits, and higher quantum computations on an ordinary computer.
STATE IN THE FIELD OF HEAT-RESISTANT COATINGS FOR HEAT-PROOF NICKEL ALLOYS AND STEELS
Authors: TERENTIEVA V. S. , ASTAPOV A. N. , RABINSKIY L. N.
Published: August 2021

Currently, in many industries, special attention is paid to increasing the reliability and economy of the products. Solving problems requires the use of materials that can work in difficult conditions, which determines the relevance of the problem stated in the article. The purpose of the article was to conduct a critical analysis of coatings developed in Russia that are diverse in composition, technological and operational properties, from the standpoint of the possibility of using them to provide a reliable material protection system under conditions that cause high-temperature gas corrosion and surface layer erosion. The main methods of materials protection were considered in the work: thermal spraying, plasma spraying, electron beam, plasma electric arc cathode spraying, vacuum deposition, chemical-thermal treatment, diffusion coating based on aluminum. Among the more effective methods, the method of self-propagating high-temperature synthesis, the method of high-energy plasma chemistry, the methods of physical deposition in vacuum are noted. The types of coatings were also highlighted and their short characteristics were given. Particular attention was paid to heat-resistant coatings based on refractory enamels since their advantages include low cost and the possibility of applying them directly to parts. A number of technical solutions have been identified that protect the alloys from high-temperature gas corrosion and erosion under long-term operation in aircraft products at high temperatures. The results of the article may be useful for further research since individual developments are uninformative from the standpoint of solving specific problems and require expensive bench testing of the claimed technical result.
SCATTERING TARGET IDENTIFICATION BASED ON RADIAL BASIS FUNCTION ARTIFICIAL NEURAL NETWORKS IN THE PRESENCE OF NON-STATIONARY NOISE
Authors: SHEVGUNOV T. , EFIMOV E. , KIRDYASHKIN V.
Published: August 2021

The paper deals with the radar target discrimination problem performed on complex radar images. The approach based on radial basis function (RBF) artificial neural network (ANN) is proposed for the identification of point scatterers placed within a radar image. The renewed concept of simple adaptive units as the foundation for network assembling allows one to design an ANN-based feature extraction scheme for the two-dimensional signal processing. It was shown that ANN implementing RBF neural processing units could be applied for the identification of radar targets described by the set of separated scatterers, even in cases where the relative distance between the scatterers is comparable to or less than the effective width of each scatterer. The obtained results indicate a high accuracy estimation of separate scatterer centers in the presence of noise which is not limited to the stationary case but supposed to be cyclostationary. It was also shown that the parameters describing the coordinates of scattering centers could be successfully extracted from the trained ANN after about one hundred epochs spent on ANN training process, which is carried out by means of modified gradient descent method. The main result is to demonstrate the possibility of using neural networks to automatically analyze radar images, which is an integral part of a set of tasks that form the target recognition problem. The proposed algorithm implements an approach of identification systems made using a neural network training procedures.
DEFORMATION OF THE HELICAL TYPE WIRE STRUCTURES
Authors: DANILIN A. N. , RABINSKIY L. N. , ZHAVORONOK S. I.
Published: August 2021

Analysis of overhead power transmission lines (OPL) involves the simulation of statics and oscillation. Solving such problems strictly requires the proper accounting of the internal conductor structure, in particular for power safety and reliability systems of information-telecommunication supply of aerodromes and aircraft systems, as well as for overhead transmission lines subjected to intense wind, especially in icing conditions. Due to the complexity of wire structures, known issues arise in the estimates of their deformations, stiffness, bearing capacity, etc. For instance, the bending stiffness of the conductor can vary considerably. Consequently, the stiffness can vary along the conductor axis as well as in time. This paper proposes a new deformation model of wire structures similar to typical OPL conductors. Such structures include not only conductors and cables, but spiral clamps intended for tension, suspension, joining, protection, and repair of conductors. Based on energy averaging each wire layer is considered as an equivalent elastic anisotropic cylindrical shell. Therefore a conductor or a spiral clamp can be modeled as a system of shells nested into each other and interacting by means of pressure and friction forces. In the process of the study, calculations were made that made it possible to formulate equations for the matrices of flexibility and cruelty of spiral structures. The interaction problem for a tension clamp with an external wire layer of a conductor has been formulated and solved. Finally, the mechanism of the force transfer from the clamp on the conductor has been investigated.
TOTAL PHENOLICS AND ANTHOCYANIN CONTENT OF TWO RED GRAPE (VITIS VINIFERA L.) CVS SAHEBI AND HALAGHO CULTIVARS AS AFFECTED BY PRUNING SEVERITY AND CANE LENGTH
Authors: MAHTAB Z. , DAVOOD B. , ESMAEIL F. , ISA A.
Published: August 2021

A popular and important grape ‘Sahebi’ and a less known local grape ‘Halagho’ in Iran, were studied to unmask the influence of pruning severity and cane length on fruit bioactive potentials; total phenolic and anthocyanin content in which they affected significantly. In this investigation, effects of 4, 6 and 8 buds per cane with pruning intensity as light, moderate and severely pruned and their interaction in the course two consecutive years, 2017 and 2018 in ‘Sahebi’ and ‘Halagho’ were studied. Results revealed striking differences which in either cultivar, pulp phenolic content was 2 to 5 fold higher in 2017 compared to 2018 with the severely pruned ‘Halagho’ at the highest (5.14 mg/g DW). Whereas, lightly pruned ‘Halagho’ with 6 buds per canes had the highest peel anthocyanin content (1.09 mg/g DW), in the same condition but with severely pruning ‘Halagho’ showed the highest anthocyanin content in pulp (0.86 mg/g DW) while in the second year, 2018, severely or lightly pruned this type with 6 buds per cane had a significant increase in phenolic compound accumulation (10 mg/g DW). From the results of this experiment, it could be concluded that the pruning of the vines is a stressor and generates enhanced phytochemical constitutes to possibly mitigate the negative consequences. However, variation in the biochemical properties manifested a notable grape cultivar dependency in addition to the time factor, which was more pronounced in ‘Halagho’ than ‘Sahebi’. To some extent the effect of cultivars on the differences of two cultivars was predominant.
SUBJECTIVE UNDERSTANDING OF THE STUDENT WHEN USING OPEN EDUCATIONAL RESOURCES
Authors: BAZYLOVA B. , ZHUSUPOVA Z. , KAZHIGALIEVA G. , ONALBAYEVA A. , KALININA V.
Published: August 2021

The relevance of the study is determined by the fact that open educational resources carry the ability to overcome the basic methodological construct complicating the learning process among students and namely the use of international experience while learning and obtaining knowledge. This study shows the aspects of functioning open educational resources and their technological basis. The novelty of the work was the formation of a model for the use of open educational resources in training of specialized courses of the Department of applied chemistry. The authors showed that the effectiveness of open educational resources use depends directly on the share of online learning and technological isolation of subjects. In particular, not only learning processes in the implementation of the program in applied chemistry, but also other disciplines that require the exchange of experience between countries and the use of a wide range of technological equipment and online structure are considered. In particular, training on the example of databases, information networks, and other spatially distributed structures are considered too. The practical significance of the study is defined by the fact that the use of open educational resources will not only intensify the learning process at the university, but also to determine the possibility of integration into the world educational space.
VALIDATION OF METHODOLOGY FOR MODELING EFFECTS OF LOSS OF STABILITY IN THIN-WALLED PARTS MANUFACTURED USING SLM TECHNOLOGY
Authors: DOBRYANSKIY V. N. , RABINSKIY L. N. , TUSHAVINA O. V.
Published: August 2021

Additive manufacturing technologies make it possible to manufacture any product in layers based on a 3D computer model, but this issue is understudied. Therefore, this paper considers the problem of describing the effects of buckling arising in the three-dimensional printing of products containing elements whose length significantly exceeds their thickness or the characteristic size of the cross section. The behavior of these elements, from the point of view of material mechanics, can be described using models of plates or beams. In this study, we compare the results of calculations obtained using the model of non-stationary thermal conductivity and thermos-elasticity with experimental data for a specific element of printed product in which stability loss occurs. It was concluded that, at the initial moments of time, the lowest critical impact coefficient is realized, which in turn makes it the most dangerous phenomenon. The possibility of changing print parameters and product geometry to exclude the mentioned effects has been investigated. The considered structural element may lose stability during the building process. The results of solving the spectral problem indicated that over time the value of the critical effect decreases and asymptotically tends to a fixed minimum value.
INVESTIGATION OF THE INFLUENCE OF THERMAL AND CLIMATE EFFECTS ON THE PERFORMANCE OF TILED THERMAL PROTECTION OF SPACECRAFT
Authors: RABINSKIY L. N. , TUSHAVINA O. V.
Published: August 2021

The article discusses the thermal protection of spacecraft under various types of thermal and climatic influences. During the pre-launch preparation, several types of icing are possible on the surface of the tiled structure, consisting of quartz heat-shielding tiles. It is very important in the process of operation, to determine normal and shear stresses during icing and the impact of ice formed in the tile gaps. It is necessary to calculate the strength and performance of the tiled thermal protection in active stages of flight of spacecraft. A mathematical model was constructed that allows, with a sufficient degree of accuracy, to research the tiled structure for strength, shear and tearing of the tile when exposed to ice. Calculations for strength, shear, and tearing of tiles under the influence of ice were performed. Theoretical and experimental studies were compared. The performed calculations made it possible to show that the tile will not collapse under the considered load. The strength of the substrate withstands the emerging shear forces. The values of the adhesion strength of ice appearing on the surface of quartz fiber heat-protective coating were obtained. It was demonstrated that the proportion of tangents in the stressed state of the tile does not exceed 10%. The proposed mathematical model for studying the characteristics of the tiled thermal protection of a spacecraft adequately describes the processes under study. Experimental studies have shown satisfactory agreement with theoretical results. The calculations performed to determine the ultimate shear stresses in the substrate showed that the strength of the substrate withstands the emerging shear forces. Consideration of climatic conditions can significantly reduce risks in the design of thermal protection of modern aircraft. The results of this study can be used in further studies, and they can also be taken into account in the construction of aircraft.
INVESTIGATION OF THE DYNAMICS OF NONLINEAR MECHANICAL SYSTEMS WITH LONG POWER LINES THROUGH DIGITAL MODELING
Authors: KONDRATENKO L. A. , MIRONOVA L. I. , DMITRIEV V. G. , EGOROVA O. V. , SHEMIAKOV A. O.
Published: August 2021

Many of the mechanisms used in industry contain input and output links connected by long lines of force. Increasing the efficiency and service life of mechanical systems with long lines is of great importance for the country's economy. For a more rational use of these devices, it is important to maintain these operating modes with maximum accuracy, usually including the required speed of the actuator and the voltage in the lines. Such parameters can spontaneously change depending on the operating conditions of the system. In the presence of various influences, similar tasks to determine the marked regimes and parameters indicating the need for their change can be solved only with the help of the corresponding theory and research methods. The article presents the problems and the method of studying two-tier mechanical systems with an infinite number of degrees of freedom on the basis of the equations of momentum and moment of momentum in differential form. Transformations with the use of well-known wave equations are proposed, which made it possible to explicitly take into account the oscillations of the speeds of motion and stresses in the force lines of mechanical systems when describing dynamic processes. The solution of systems of partial differential equations is given using the Laplace transform, which made it possible to obtain general equations of motion and, after some simplifications, proceed to ordinary differential equations that take into account the dynamic features of systems with distributed parameters. The modernized Runge-Kutta method obtained solutions and carried out numerical simulation of transient processes in the hydraulic drive, the results of which have good convergence with full-scale experiments.
POTENTIAL USE OF MANGO GUM (MANGIFERA INDICA) IN PHARMACOLOGICAL SYSTEMS
Authors: SILVEIRA M. C. A. , GLÓRIA R. S. L. , BARBOSA K. M. , SANTOS L. S. S.
Published: August 2021

The possibility of using natural or modified polymers to formulate drug-containing nanocapsules is a pharmaceutical option for cases in which an increase in the half-life of medications in the body and a decrease in side effects is required, and may also be used for better pharmacological targeting of the site. Related to low production costs with these characteristics and renewable availability. Gums and mucilages have been studied for use in natural alternative drug delivery systems. The gum from the trunk of Mangifera indica has few studies aimed at this purpose, although it has shown promising results in previous studies. Characterization of the gum formation pathways are explained, as well as their extraction and purification. The similarity of properties of Acacia gum widely used in tablet blends has been confirmed. Mangifera indica gum was also used for accelerated drug release. The versatility of this gum is associated with the presence of mucilage. Chemical modifications of the Mangifera indica gum and mixtures among other gums may be made to adapt their properties to the various forms of controlled drug release. Several isolated compounds with pharmaceutical properties are demonstrated. Physical chemical characteristics of several articles on this gum have been compiled. The techniques already used for the formation of nanocapsules through Mangifera indica gum are presented. Several studies have been reported specifically using Mangifera indica gum from the Mango trunk used as drug release. These studies justify a summary of the pharmaceutical properties for drug delivery already performed with this gum. Complementary studies for utilization and valorization of Mango cultivation are suggested.
GEOCHEMICAL SPECIATION AND BATCH MODE SIMULATION IN THE CARBONATE DEPOSITIONAL ENVIRONMENTS
Authors: KLUNK M. A. , DASGUPTA S. , DAS M. , WANDER P. R. , DI CAPUA A.
Published: August 2021

Geochemical modeling has been frequently used to understand and interpret water-rock interactions in sedimentary basins. Thermodynamic data, kinetic parameters, numerical methods, boundary history, and boundary conditions are factors affecting any geochemical modeling system. In the present study, we have attempted to establish a geochemical speciation model by comparing the interaction of formation water and carbonate rock in the carbonate depositional settings of Cambrian successions of Bachu and Tarim area. A comparative study of geochemical speciation has been performed using four different software: PHREEQCTM, GWBTM, TOUGHREACTTM, and GEODELING. GEODELING is a geochemical code simulator that we have developed, and the details are presented further in this work. All the software has been analyzed minutely, considering the distribution, mobility, and availability of chemical species in geological environments. Very similar results in speciation are observed while working with low-temperature systems. A discrepancy can be observed in the results while working with high temperatures. However, a thorough Newton-Raphson formulation, scaling of algebraic equations and master-species switching helps to reduce the possibility of failures of the numerical method used in PHREEQCTM.
ADHESION OF PERIODONTAL PATHOGENS TO MATERIALS USED FOR LONG-TERM TEMPORARY CROWNS
Authors: UTYUZH A. , NIKOLENKO D. , YUMASHEV A. , VOLCHKOVA I. , SAMUSENKOV V.
Published: August 2021

Provisional crowns are widely used in prosthodontic treatment in dentistry, and new materials for temporary crowns, including polyetheretherketone, have emerged, which have high-quality requirements for use in long-term temporary prosthetics. Of particular importance in prosthetics are the features of adhesion of pathogenic oral microflora to orthodontic structures. This study evaluated the adhesion of cariogenic and pathogenic periodontal bacterial flora and Candida species to unpolished and polished Dentokeep polyetheretherketone (PEEK), polished polymethyl methacrylate (PMMA) material (Re-Fine Acrylic), and hotcuring acrylic plastic ─ a powder-liquid type, where the powder is a suspension graft fluorine-containing copolymer, and the liquid is a mixture of acrylic monomers, and oligomers─(Sinma-M) recommended for manufacturing long-term temporary crowns. The effect of polishing or un-polishing the study material on the adhesion of various microorganisms was studied. Polishing of Dentokeep PEEK significantly influenced primary adhesion. Microbial adhesion to sample materials was studied using ultrasonic cavitation. Adhesion of microorganisms to each material was categorized as low (0–0.27), moderate (0.28–0.69), or high (0.70–1). Streptococcus sanguinis, Prevotella intermedia, and Candida albicans adhered moderately to unpolished Dentokeep PEEK, whereas Porphyromonas gingivalis and Candida krusei were highly adherent. Candida species and P. intermedia pathogenic periodontal strain moderately adhered to polished Dentokeep PEEK, whereas S. sanguinis and P. gingivalis were highly adherent. Temporary crowns require additional hygienic measures to eradicate cariogenic (acidogenic), pathogenic periodontal, and fungal microbiota and maintain the normal qualitative and quantitative composition of oral microbiocenosis during prosthodontic treatment. In conclusion, PEEK is a promising material for the manufacture of long-term temporary crowns.
SENSITIVITY OF RAT BRAIN SENSORIMOTOR CORTEX NEURONS TO MEDIATORS IN HEMORRHAGIC STROKE
Authors: MESHCHERYAKOV A. , KOPLIK E. , VOLKOV V. , IONKINA H. , BUDNIKOV M. , BORISOVA E.
Published: August 2021

The problem of post-stress disorders of cerebral circulation, the most severe of which is cerebral hemorrhage, or hemorrhagic stroke, is extremely urgent. Concerning the survival rate, previous studies have shown that in the same type of conflict situations, individuals resistant and predisposed to emotional stressful influences are clearly distinguished. However, the neural mechanisms providing neuromediatory regulation of responses to stressful effects are still little studied. The analysis of neurochemical sensitivity to acetylcholine and norepinephrine of the sensorimotor cortex neurons of rats having different activity according to behavior parameters, i.e., resistance to emotional stress influences before and after experimental hemorrhagic stroke (EHS) was carried out. The recovery process after an EHS due to neural activity in prognostically stable (VA) and predisposed (NA) to stressful situation rats has individual characteristics. Acute stress influence before EHS development changes the nature of neurons activity of the sensorimotor cortex in VA and NA rats on the third and seventh day after EHS. EHS leads to specific changes in the sensitivity of neurons to acetylcholine and norepinephrine in VA and NA rats. Acetylcholine microionophoresis causes activation of the neuron impulse activity in VA and NA rats, and these changes are the same after EHS. Acute stress influence before EHS development does not change nature of neuron responses to norepinephrine microionophoresis in VA animals. On the contrary, in NA rats loss of neuron sensitivity to norepinephrine during EHS development against stress was noted. It is possible that acute stress influence before EHS development can change brain noradrenergic system activity in NA rats, which are prognostically predisposed to stress influences. The data obtained stress the plasticity of the central nervous structure in development of response to stressful influences. (The ethics commission approval protocol number is 18-15 from 13th of Marth 2018.)
ASSOCIATION OF THE DELETION ALLELE OF THE INSERTION/DELETION POLYMORPHISM OF αIIbβ3 INTEGRIN GENE AND METABOLIC SYNDROME IN YOUNG NORTHERNERS
Authors: KORNEEVA E. V. , VOEVODA M. I. , SEMAEV S. E. , MAKSIMOV V. N.
Published: August 2021

The rationale for the present study is explained by a high spread of metabolic syndrome among the young population, living in an area equivalent to the Far North. The study is aimed at the investigation of the association between a deletion allele of the polymorphism of deletion/insertion in the αIIbβ3 integrin gene and metabolic syndrome in young residents Khanty-Mansiysk Autonomous Okrug – Ugra (Russia). The 758 young people aged 18-44 (mean age 36.62±5.12 years old) with metabolic syndrome and 77 healthy young people without metabolic disorders were examined. The carriership of the allele I associated with the cardiovascular risk was revealed in 63% of the examined patients that had an increased risk of the development of metabolic disorders (OR 1.409, 95% CI 0.858-2.311, p=0.253). There was no significant difference between the native and non-native populations in the rate of occurrence of allele I (62.2% and 64.7%). Genotype II had significant association with arterial hypertension (OR 1.377, 95 % CI 0.912-2.080, p=0.073), obesity (OR 1.353, 95% CI 0.825-2.219, p=0.071), hypercholesterinemia (OR 1.386, 95% CI 0.977-1.966, p=0.115), hypertriglyceridemia (OR 1.232, 95% CI 0.889-1.706, p=0.097). It was established that the non-native population had a higher risk of the development of abdominal obesity, arterial hypertension, and hypercholesterinemia, unlike the native population that had a significantly higher risk of the development of triglyceridemia. The materials of the article can be useful for the evaluation of genetic predisposition to myocardial infarction, stroke, and thromboembolism, which will allow for timely indication of preventive measures.
DEVELOPMENT OF A METHOD FOR ASSESSING LEARNING OUTCOMES THROUGH AUTOMATED TESTING MANAGEMENT
Authors: KAZANBAYEVA A. S. , IKLASSOVA K. E. , KULIKOV V. P.
Published: August 2021

Testing knowledge is an important part of the pedagogical process, as it helps to improve the quality of professional knowledge, contributes to the effectiveness and efficiency of training. This article discusses the use of several approaches to building a fuzzy diagnostic expert system for knowledge testing. The aim of the research is a comprehensive optimisation of the process of mass test information processing in order to obtain reporting data, consideration of clear and fuzzy tests, drawing the analogy between clear and fuzzy tests, proposal and justification of different schemes of summing up the testingandproposal of one's own prototype of automated expert testing system which covers all stages of the testing process. Generally speaking, testing, as an algorithmic problem, can be represented as a problem of building an expert system to evaluate knowledge of testees. Such systems are used in solving many problems related to effective management, scientific research, and the like, where it is necessary to get the result with a limited amount of reliable information. It is established that the classical theory of tests has a number of controversial assumptions, and the results of its application have serious practical drawbacks. Therefore, the main principle of the approach in the work is the separation of the creation of a bank of test tasks and the process of compiling tests (bank of test material) and testing.
STUDY OF THE QUALITY OF LOW-CLASS WHEAT AND BREAD OBTAINED BY THE ACCELERATED TEST METHOD
Authors: URSUNBAYEVA S. A. , IZTAYEV R. , GOMEDOV R. , YAKIYAYEVA A. , ULDABEKOVA B. Zh.
Published: August 2021

The quality of bread is determined by the quality of the raw materials used, and above all, flour and water as the main types of raw materials. The article presents the results of a study of physico-biochemical properties, indicators of bread baking by the accelerated method, obtained from finely ground soft wheat flour 3, 4, 5, and out-of class. A baking dough prepared in an accelerated way for 2-3 minutes can improve its rheological properties, reduce baking time to 36 minutes, improve the quality of bread from low-quality soft wheat flour. In accordance with the purpose of the study, the changes in the physicochemical properties of soft wheat grains 3, 4, 5 and out-of class were studied, finely ground whole-ground flour separately from different classes of soft wheat grains was obtained, and the quality of bread prepared using the accelerated test method from soft wheat flour was studied, different classes. In general, all wheat samples can be classified as recommended for consumption since they have increased organoleptic and physico-biochemical parameters of rheological properties compared to a wheat sample out-of class. Thus, the results of studies using the accelerated test method showed that wheat of classes 3, 4, and 5 studied formed the necessary properties of semi-finished products and contributed to improving the quality of bakery products and improving their quality.
THE STARTING PROCESSES OF A CAR ENGINE USING CAPACITIVE ENERGY STORAGES
Authors: MALEEV R., , ZUEV S. M. , FIRONOV A. M. , VOLCHKOV N. A. , SKVORTSOV A. A.
Published: August 2021

The article presents data on experiments related to the start-up process of an automobile engine using capacitive energy storage. It is shown that capacitive energy storage devices can be used for efficient start-up of an internal combustion engine. The aim of the article was to study the systems of electric start of vehicles combustion with capacitive energy storage as source of electric energy using a mathematical apparatus that allowed analyzing the process of starting a vehicle engine with capacitive energy. In the course of work, analytical dependences on the time and angle of rotation of the crankshaft of the internal combustion engine (number of working strokes) of the main parameters of the electric starter starting system with a constant moment of resistance on the shaft of the internal combustion engine were obtained. Mathematical calculations and simulation of operating modes in specialized software products were carried out. The results of the experiment showed that the process of scrolling the internal combustion engine with an electric starter when it is powered from capacitive energy storage devices differs significantly from the process of scrolling when powered from a rechargeable battery. Due to the large proliferation of batteries in vehicles and the search for alternative technological solutions to them, it can be said that the results obtained in this article are of practical value in the framework of modern electrical equipment technology.
CHEMICAL COMPOSITION OF AP-MA-05 ARCHAOLOGICAL SITE SOIL IN MACAPÁ- AMAPÁ
Authors: XAVIER N. S. , XAVIER J. R. M. , COSTA J. A.
Published: August 2021

Archaeo anthrosols are soils that record human occupation and can be found in ancient housing settlements known by archaeological sites. This type of soil generally presents distinct characteristics of the surrounding soils due to changes in its chemical properties caused by past human activities and its study helps to understand these activities and the organization of these prehistoric populations. Therefore, the objective of this research was to characterize the soils of the archaeological site AP-MA-05 in relation to its chemical composition, pointing to the alterations suffered as a result of past human activity, in comparison to its adjacent area. The study area is in the municipality of Macapá, Amapá State, on the campus of the Federal University of Amapá (UNIFAP). To reach the objectives, 41 soil samples were collected in two transverse lines in the area of the archaeological site and, for the purpose of comparison in the adjacent area, a trench was opened in which the soils were collected for the pertinent determinations. The chemical identification was measured by pH determination in water, available phosphorus, calcium, magnesium, exchangeable potassium and aluminium, potential acidity. The chemical data showed a great variability in the soils of the archaeological site and superior fertility to the soil of the adjacent area, inferring that the alterations observed in the site are due to the previous human activities as the soils present the same origin. The chemical determinations also indicated the growth of the archaeological site in the south direction, outside the limits established in previous researches.
THE AMINO ACID COMPOSITION OF UNCONVENTIONAL POLY-CEREAL FLOUR FOR PASTA
Authors: OSPANOV Abdymanap , MUSLIMOV Nurzhan , TIMURBEKOVA Aigul , MAMAYEVA Laura , JUMABEKOVA Gulnara
Published: August 2021

Pasta producers know three pasta formulations for making pasta products with the increased nutritional and biological value from unconventional poly-cereal raw materials. These pasta formulations composite flour mixtures of cereal/legumes with added dry wheat gluten. The flour mix was formulated through the design method that allows regulating the content of nutrients in the product to meet the requirements of rational and adequate nutrition and provide a therapeutic and preventive effect. This article explores the drying kinetics of pasta from unconventional raw materials and reports on the quality and consumer properties of pasta. Results show that with the percentage of dry wheat gluten increasing in the poly-cereal flour mix, the percentage of both essential and non-essential amino acids in the mix also increases. Formulation No. 1 provides a mix with the maximum percentage of amino acids in it. The said maximum is significantly higher than the total concentration of amino acids (% by weight) in a mix made according to formulations No. 2 and No. 3. The increase in dry wheat gluten from 15% to 35% leads to a sharp increase in the concentration of essential amino acids (tryptophan and lysine). A significant increase in other essential amino acids (valine, isoleucine, leucine, methionine, threonine, phenylalanine) was not detected.