bluuebunny/crossref_metadata_2025 huggingface dataset:
Lamination of wood boards with modified amino-formaldehyde resins
Authors: Yakobashvili V. D. , Tsvetkov V. E. , Machneva O. P. , Semenchenko V. A. , Podolny V. A.
Published: August 2023

This paper focuses on the development of the formulation of modified amino-formaldehyde oligomers, the study of their properties, obtaining impregnation compositions based on them and the study of the properties of the finished product -reinforced wood particle board. As a modifying component we chose ethylene glycol, salts of organic acids (modifier CN) and alloying additive “OLIGO LD”. Ethylene glycol at the stage of synthesis was used to improve stability and elasticity of oligomers. The CN modifier was introduced during the synthesis of oligomers, which allowed to influence the properties of the obtained products in a directed way.
Technology of moisture-resistant chipboard using amino-formaldehyde binder
Authors: Tsvetkov Vyacheslav , Machneva Olga , Podolny Vladimir , Semenchenko Vladimir , Yakobashvili Victoria
Published: August 2023

In this paper we study the possibility of using modified amino-formaldehyde resins in the production of moisture-resistant wood particle boards. As a modifier of amino-formaldehyde resins it is proposed to use a by-product of melamine production -melan, which is a powder of light brown color, insoluble in water. Melan in its chemical composition and properties is largely similar to melamine, but unlike the latter it is an available raw material for the synthesis of polymers. This is the high market value of commercial melamine. Melamine, on the other hand, is often a waste product that is absolutely free. Aminoformaldehyde resins modified with melamine, despite its dark coloring, provide particleboards with a coloring identical to those obtained from conventional aminoformaldehyde resins. However, the properties of the obtained materials allow them to be classified as moisture-resistant.
Development and research of basalt plastic material for the flood protection structures
Authors: Lukachevskaya I. G. , Kychkin A. K. , Lebedev M. P. , Gavrilieva A. A. , Kychkin A. A.
Published: August 2023

Due to the increasing number of catastrophic floods around the world, creation of an effective system to protect against natural disasters became particularly relevant. The paper investigates introduction of the basalt fiber to reinforce the composite sheet piles. Influence of the reinforcing fiber interlacing type on the nature of plastics destruction was established. Results of the work prove that basalt plastic (BP) exhibits higher climatic resistance than the fiberglass plastic (FGP). After post-curing, strength characteristics relative to the second year were decreasing by 15% with BP and by 22% with FGP in extension, and the strength limit in bending was decreasing by 12% with BP and by 47% with FGP. It was experimentally shown that under a long-term stationary thermal and humidity effect of 23°C/68RH, diffusion was observed on the basalt and fiberglass plastics consisting of two stages. The first stage had a satisfactory statistical error and was adequately approximated by the Fick’s diffusion model and the relaxation model. The second stage had an unsatisfactory statistical error for approximation and was of the spasmodic nature, while the jump in FGP was the largest indicating that the FGP was more susceptible to destruction exposed to the influence of long-term temperature and humidity regime of 23○С/68 RH, than the BP.
Investigation of the structure and properties of surface composite layers on multi-alloyed steels
Authors: Ishmametov D. A. , Pomelnikova A. S. , Fomina L. P. , Karpukhin S. D.
Published: August 2023

In this work were studied the structures and properties of surface composite layers obtained by chemical-thermal treatment and combined chemical-thermal treatment, combining liquid-free electrolysis-free boriding with gas nitriding. The properties of surface composite layers on steels with different alloys are analyzed depending on various parameters of chemical-thermal treatment. The study showed that, during boriding, phases of iron borides FeB, Fe2B are formed on the surface of the samples, and their volume ratio strongly depends on the degree of steel alloying. A strong effect of carbon on the morphology of surface layers was revealed. Finely dispersed strengthening particles were found in the borated layers on the VKS-5 steel, large superhard particles on the Ch12MF steel near the borated layers. The study of the microstructure of the composite layers showed that during gas nitriding, a layer 80 μm in size is obtained, which penetrates deep into the borated layer. The study of the properties of surface layers showed that carbon has the greatest influence on the formation of borated layers. The resulting composite layers are characterized by reduced microbrittleness and increased corrosion resistance.
Aging of PLA/NR electrospun fibers under the influence of UV-irradiation, water and soil environment
Authors: Podzorova M. V. , Tertyshnaya Yu. V. , Godyaeva M. М. , Khramkova A. V.
Published: August 2023

Research in the field of the influence of environmental factors on composite materials based on polyesters is very relevant, as such materials are gaining more and more use in various industries and agriculture. This paper presents the results of the influence of UV-irradiation, water and soil on PLA/NR nonwoven fibers. The content of NR was 5-15 wt.%. It was found that the presence of NR over 10 wt. % inhibits photolysis. After 300 hours of irradiation, the melting point of 100% PLA decreases more significantly than in composites with NR. The IR-spectroscopy method confirmed the occurrence of the process of photooxidative degradation in fibrous samples. Biodegradation in soil proceeds more actively in PLA/NR fibrous composites than in pure PLA. Apparently, an increase in the proportion of the amorphous phase in the composites and the bioavailability of rubber contribute to this process.
Analysis of UAV wing load calculation
Authors: Lingjia Zhang
Published: August 2023

According to the existing wing structure design cases, design a simple model of the UAV wing according to the engineering needs, and use the flow-solid coupling function of the ansys finite element analysis software to calculate the working load of the wing structure.
The use of composite materials in load-bearing elements of an adaptive wing
Authors: Kibanov Kirill , Novikov Mihail , Azarov Andrey
Published: August 2023

The article discusses methods for manufacturing power elements of an adaptive wing from composite materials, as well as various principles for changing the configuration of an adaptive wing. A comparison is made of the aerodynamic characteristics of an adaptive wing and a wing with traditional high lift devices.
Architecture of composite multilayer semiconductor nanostructures
Authors: Vetrova N. A. , Kuimov E. V. , Meshkov S. A. , Makeev M. O. , Sinyakin V. Yu. , Shasurin V. D.
Published: August 2023

The problem of ensuring the operational parameters of composite multilayer semiconductor nanoscale structures at the design technology stages is solved. A mathematical model based on the physics of processes occurring in the structure during operation is developed. The problem is solved for the resonant-tunnelling AlGaAs nanoheterostructures.
Alkali resistant epoxy binders for pultrusion
Authors: Leshtaev A. I. , Storozhuk I. P. , Orlov M. A. , Polikarpova I. A. , Ivan'kov R. R. , Muzyka S. S.
Published: August 2023

Alkali-resistant hot-curing epoxy binders based on ED-20 and new amine hardeners “Amikrost” have been developed, intended for the production of glass-composite fittings for construction purposes. The rheological properties of epoxy compositions were determined, using differential scanning calorimetry and thermogravimetric analysis, the temperature dynamics of the curing process of epoxy compositions and the thermal-oxidative resistance of cured samples were studied. The alkali resistance of cured epoxy compositions and specimens of composite reinforcement in 40% alkali aqueous solution was evaluated. It is shown that the developed amine hardeners provide high alkali resistance of composite reinforcement in comparison with the currently used anhydride hardener iso-MTHPA, which is especially important for reinforcing buried and hydraulic concrete.
Influence of coloring on the properties of epoxy binders and fiberglass rebar based on them
Authors: Leshtayev A. I. , Storozhuk I. P. , Orlov M. A. , Polikarpova I. A. , Ivan'kov R. R. , Nelyub V. A.
Published: August 2023

At present, polymer composite materials are widely used in the construction and automotive industries, products for which must meet not only operational, but also aesthetic requirements. Since color is one of the most important design elements, much attention is paid to the coloring of structural composites. There is a fairly wide range of different methods for coloring polymer composites, but each method has both advantages and disadvantages. This article discusses two methods for coloring a hot amine-cured epoxy composition, which is used for the manufacture of composite fiberglass reinforcement: by adding pigment and organic dyes to the epoxy composition. It has been found that organic dyes dissolve in all components of the epoxy composition, but become colorless upon heat treatment. When adding an insoluble dispersed pigment, the color remains unchanged even after the thermal curing of the epoxy matrix. The addition of up to 0.5 mass parts of iron oxide pigment (“red FEPREN TP-303”) to the epoxy binder slightly reduces the mechanical strength of the composite and significantly increases its thermal stability.
Some features of flat fiberglass specimens’ behavior under three-point bending
Authors: Kayumov R. A. , Strakhov D. E.
Published: August 2023

The authors carried out the experimental works devoted to the problem of describing the processes occurring under long-term loading of composite materials. They studied a glass-reinforced plastic (GP) flat specimen under three-point bending and assumed the deformations normal to the section are purely elastic, and the transverse shear deformation consists of two parts –elastic, and creep deformations and damages formed as a result of accumulation. The authors considered a variant of the creep ratios according to the hardening theory. In previous research authors determined its parameters based on the analysis of the tubular samples operation. It was found that even for thin beams, in contrast to a purely elastic problem, taking into account creep under transverse shear leads to inelastic deflection components that are comparable with their elastic values. The authors presented the results of numerical calculations. It is concluded that at large time and loads, deformations appear in the sample caused by the accumulation of damage.
Self-healing polyurethane-polypropylene oxide copolymers for the protection of carbon and glass fiber-reinforced composites
Authors: Zalina A. L. , Soboleva J. A. , Zakharova D. V. , Storozhuk I. P.
Published: August 2023

Polyurethane-polypropylene oxide block copolymers containing fragments of an adduct capable of self-healing by the Diels-Alder reaction mechanism have been synthesized and studied for the first time. All obtained polyurethane copolymers were characterized by IR spectroscopy. The temperature transitions and thermal stability of copolymer melts were determined by using the methods of differential scanning calorimetry and thermogravimetric analysis. The self-healing effect was confirmed using a thermal cycling procedure on pre-damaged samples of modified polyurethanes and surface morphology studies. The perspective of the work begun on the creation of self-healing protective polyurethane coatings are shown.
Justification choice parameters material input receiving and distributing device in the horizontal type air grain cleaning machine
Authors: Kravchenko Lyudmila , Sibirev Alexey , Mosyakov Maksim , Koltsov Alexander , Anastasia Mazurova
Published: August 2023

The paper presents studies to determine the angle of inclination of the surface from the coefficient of friction for organic glass in an air grain cleaning machine. Earlier studies of the physico-mechanical properties of grain seeds have shown that for steel, the angle of descent of wheat is 36.2 – 37 degrees at a humidity of 15%-16%.
Mathematical modelling of the hydromechanical drive of the test bench for plunger hydraulic cylinders with energy recovery
Authors: Rybak Alexander , Meskhi Besarion , Pelipenko Alexey , Rudoy Dmitry , Olshevskaya Anastasiya , Serdyukova Yuliya , Odabashyan Mary , Alentsov Egor
Published: August 2023

Reliability is a significant parameter of machines, mechanisms, drives, technological equipment and its component parts, including hydraulic motors. Reliability is checked and confirmed by carrying out resource tests, the results of which reveal the characteristics and properties of materials, components and working fluids that are used in the production of hydraulic cylinders and during operation. One of the practical ways to determine reliability is testing. The aim of the work is to improve the theory and methods of calculation and design of the hydromechanical drive system of the service life test bench of plunger hydraulic cylinders through the use of an energy recovery scheme that provides an increase in the energy efficiency of the testing process. Developed on the basis of the application of the theory of volumetric rigidity, a mathematical model of the hydromechanical drive system of the plunger hydraulic cylinder service life test bench made it possible to compare the influence of various design and functional parameters of the elements of the hydromechanical system of the stand on the dynamic performance and energy efficiency of its drive.
Application of the method of mathematical statistics to study the wear of parts of modern machines
Authors: Shapiro Evgeny
Published: August 2023

This article describes the method of mathematical statistics for studying the wear of parts of modern machines. It is examined how the service life of the parts is established. It was also assumed that the statistical data on the size of worn parts obey the law of normal distribution. The figure presented in the paper illustrates the scheme for determining the inter-repair service life of the part for this case according to statistical data. An example is considered that allows to establish the norm of the maintenance period of the support roller of a modern tractor VT-150. This article is recommended for agricultural specialists, researchers, teachers, postgraduates, undergraduates and students of agricultural universities in the field of training “Agroengineering”.
Improving machine assemblies’ diagnosis with the use of thermal imaging camera
Authors: Sivakov Vladimir , Gryadunov Sergey , Zagidullin Ramil , Sabitov Linar , Scherbakov Alexander , Belyaev Aleksandr
Published: August 2023

Thermal imaging camera is used in the construction industry, energy industry and some other areas. Considering that a vehicle uses engines, interacting parts, electrical wiring and electrical equipment, it is advisable to use thermal imaging diagnostic method for vehicles as well, including specialized (trucks, road construction and others). Thermal imaging method of machinery diagnosing can be used in the conditions of the specialized automobile service enterprise (dealer or universal), visiting service (servicing of specialized machines by dealer), as well as using own service base of the enterprise. This task is especially urgent in connection with the necessity of pre-shift inspection, which is usually carried out by the company's own maintenance service. Rapid vehicle diagnosis using instrumented testing is therefore an important task. Brakes, bearings, engine, gearbox, transfer case, axles and electrical wiring can all be checked with a thermal imaging camera. Possibility of application of a thermal imaging camera for determining the condition of an angle or an aggregate both by comparison (brake mechanisms, hub bearings) and by determining the actual temperatures of the diagnosed object and comparing them with the approximate values which are determined beforehand on the basis of the previously made measurements. Thus, the use of thermal imaging method of vehicle diagnostics will allow for faster and more accurate assessment of the actual condition of vehicle units and assemblies, increasing its efficiency.
Service life predicting of the piston ring with laser-hardened cylinder liner
Authors: Alisin Valery
Published: August 2023

The article considers the issues associated with the evaluation of hardening treatments influence on the service life of the piston ring in the cylinder of a heavy-duty diesel engine. The statement about the high efficiency of laser hardening of cylinder liners made of cast iron is substantiated. Model experiments on a laboratory friction machine investigate the wear resistance of the friction surfaces of the coupling piston ring-cylinder liner. The effect of piston ring wear on the loss of elasticity and the service life of the coupling is analyzed. The calculation method determines the service life of the coupling and analyzes the efficiency factor of the laser hardening treatment. On the basis of the study, it was found that laser hardening of the friction surfaces of cast-iron cylinder liners has a positive effect on the coupling wear resistance, but increases the wear of the piston rings. To eliminate the increase in wear resistance of piston rings, it is proposed to make them from steel and apply laser treatment of a wear-resistant coating from a high-entropy alloy of the Fe-Cr-W-Mo-Co-Ni system, which can significantly increase the service life of the piston ring-cylinder liner coupling in heavy diesel engines.
Simulation of forced vibration of a wedge pair under the impact of variable force
Authors: Khudjaev Mukhiddin , Rizaev Anvar , Pirnazarov Gulomjon , Mirzaeva Musallam
Published: August 2023

The forced oscillations of a wedge pair under the effect of a variable force are investigated in the article. The general solution to the differential equation of forced oscillations of a wedge pair is chosen in the form depending on some unknown function. An equation for this function is obtained for the cosine form of the virtual displacement of the wedge under longitudinal displacement. This equation is obtained on the basis of the principle of virtual work of inertial forces, elastic forces, and external dynamic forces with virtual displacement. As a result, the solution to the differential equation of forced vibrations of a wedge pair under a variable longitudinal external force was obtained, and calculations were performed on the basis of the obtained solution. Research methods are based on the principle of virtual displacement, the method of mathematical modeling, and the analytical method of their solutions.
Problems with Uzbek tour guide students
Authors: Ermanov D. R. , Soatova Sh.B.
Published: August 2023

This article recognizes the teaching of foreign languages in Uzbekistan on the example of English and how well it meets the requirements of international tourism, the problems associated with foreign languages in the industry and the specialization of tourism required by foreign language audiences.
Use of English terminology in technical and transport universities
Authors: Mustaeva G. S. , Qurbanova M. M. , Ganihanova M. B.
Published: August 2023

In the process of globalization, the rapid spread of information sources, the enormous increase in the amount of socially important (scientific, technological, cultural, etc.) information cannot fail to have an impact on any society. In addition to traditional information technologies based on creating, transmitting, receiving, storing, processing, multiplying, automating processes and presenting information in the form of books, newspapers, photos and movies, conditions for the emergence of new types of information technologies in production using information and communication technologies created New information technologies are not displacing traditional ones, but at the same time, the amount of information is not decreasing. In society, there is a problem of human adaptation to information or, to put it differently, adaptation to information. The emergence and development of a large number of sign systems, as a result of which a multi-component “information field” is formed, constitutes a unique world of information. In modern pedagogy, the direction called visual literacy (English visual literacy) deals with the problems of forming the skills of using visual and audiovisual information.
Semantic-Syntactic relations and cognitive features of Russian and Uzbek pseudonyms
Authors: Ibragimova S. S.
Published: August 2023

This article discusses and analyzes the semantic-syntactic relations and cognitive features of Russian and Uzbek pseudonyms, national and cultural originality of pseudonyms. If we compare the languages and cultures of different peoples, we can distinguish matching and non-matching elements. An analysis of the semantics of pseudonyms showed that a pseudonym retains a pre-onomastic meaning and has a peculiar semantics, and the bases of pseudonyms inform about the character of a person, about physical properties and shortcomings, about behavior, about origin, about comparing a person with various objects, animals, plants, about a profession, an occupation, a social position, a particular life event, etc. It should be also emphasized the role of metaphorization in the formation of pseudonyms, since the process of metaphorization (as it is defined by cognitive linguistics) is a very important tool in the creation of pseudonyms. It is closely connected with the literary text, as it predetermines the special position of the context, acting as an aesthetically significant component of the literary text.
Importance of CLT in teaching vocabulary to adult learners
Authors: Khasanova M. Sh. , Mirzayeva N. B.
Published: August 2023

The communicative idea is highlighted by Communicative Language Teaching (CLT), which began in the 1970s. Communication is frequently hampered by lexical issues; communication fails when people use the wrong words. The ability to communicate is the ultimate goal of language learning. The purpose of this article is to clarify the value and necessity of the CLT application in teaching English vocabulary to adult learners. The goal of this study is to identify how the Communicative Language Teaching approach is employed in English classes as well as the methods and tools that teachers use to help their students develop their vocabulary skills. The participants are 10 pre-intermediate level students. In this investigation, a mixed method approach was used: a questionnaire and class activities were done to gather the data. It is crucial to emphasize that a range of tactics, in addition to those already described, can be used to give students more chances to use the language verbally in class. To help students develop their oral skills, teachers often offer other forms of feedback, such as elicitation and metalinguistic feedback.
Cross-linguistic influence: The role of L1 and L2 differences in acquiring second language
Authors: Komilova Maftuna
Published: August 2023

This article discusses the role of first language and second language differences in second language acquisition process of L2 learners. This small scale research focuses on finding answers to three main questions: a) what are the main reasons for transferring L1 knowledge into L2; b) what should learners do to deal with this problem; and c) when does transfer start to diminish. The participants of this study are 21 students who are studying in their eleventh grade. According to the analysis of results, (1) main reasons for language transfer are different language structures and not enough knowledge in target language (knowledge gap in the target language) these, in turn, can slow down language learning pace of learners; to deal with the problem (2) learners should devote much time to learning (analyzing speeches, listening to podcasts, reading authentic articles, communicating with native speakers) and expose to L2 as much as possible, finally, (3) the influence of their first language has diminished significantly after time passed, but it didn’t disappear fully.
Lexical-Semantic features of the arabic cognates related to the educational process
Authors: Rashidova N. B. , Tuychiyeva O. S.
Published: August 2023

The word-stock of the Uzbek language consists of native and assimilated words. Until the early 20th century, the assimilated stratum was enriched with Persian-Tajik and Arabic words. By the beginning of the 20th century, Russian words, and later international words, began to intensify. Although the process of mastering Persian-Tajik and Arabic words slowed down, the mastery of these languages retained the main position of the explanatory dictionary of the Uzbek language. Farsi-Tajik and Arabic words began to acquire the status of their stratum in relation to Russian-international words. Most of these words are difficult to distinguish without etymological analyses and dictionaries. Such similarities were accepted as similarities only by scholars, and in colloquial terms they became the words of their class. The processes of semantic development of borrowed words occurred within the Uzbek language. In this article the changes of roots associated with the learning process, observed during the historical development of semantics of Arabic lexemes are maximally highlighted.
Teaching academic writing in English: Approaches and products
Authors: Rasulova M. , Ataullayeva S.
Published: August 2023

English is the number one world language today. Writing in this language is the main task of every staff, including students. The article describes the difficulties that students encounter when mastering a written language in a foreign language course in English for Academic Purposes in the context of the specifics of the course. Methodological approaches to teaching foreign language written speech are analyzed, their strengths and weaknesses are identified, the possibility of using tasks inherent in these approaches in the course of academic writing to overcome the described difficulties is considered. Examples are given illustrating how tasks can be combined when writing an essay and annotation. The article shows some experiments with tables and explanations. The results of this article can be used in various scientific works and educational manuals in the future.
Experience of teaching ghazal genre in schools of Uzbekistan
Authors: Tukhliev B. , Tukhlieva D. B.
Published: August 2023

The literature curriculum includes samples of lyrical works of various genres, and among them, especially the classical lyric genre –ghazals, requires a special approach. In the learning process, traditional methods of interpretation and are widely used in the analysis of the text of ghazals. But today there is a growing need for new approaches and the use of modern methods and technologies in the interpretation of gazelles. This article describes the description and essence of the new methodology “System Analysis” in teaching the ghazal genre in secondary schools. It explores interactive methods that serve to reveal the content of gazelles, the possibilities of digital technologies to increase student interest in classes, the impact of such activities on the level of acquisition of relevant skills by students. The content of the experimental work carried out in various regions of Uzbekistan is explained, and the results are calculated using mathematical and statistical methods. Apart from all the oft-sited, the current state of teaching ghazal genre samples in secondary schools was studied and practical recommendations were given for its improvement.
Psychological aspects of the communicative process of using interactive methods
Authors: Khidoyatova D. A.
Published: August 2023

This article presents the results of a study conducted in schools in Samarkand, Syrdarya regions and the city of Tashkent in 2012-2019. On the basis of the conducted research and the results obtained, the important factors of the organization of the communicative process in interactive learning are analyzed. The analysis presents a set of rules and recommendations for the teacher to listen and respond to the students, as well as forcing them to take the correct positions during the dialogue. In general, the main psychological aspects of the correct organization of the communicative process in interactive learning are analyzed.
Effect of comorbid conditions on the course of COVID-19 in patients with chronic diseases of the cardiovascular and pulmonary systems
Authors: Tashkenbaeva E. N. , Abdieva G. A. , Muhiddinov A. I. , Khaydarova D. D. , Togaeva B. M.
Published: August 2023

The pandemic of the novel coronavirus infection COVID-19 has become a serious challenge to humanity. Prior to this period, cardiovascular diseases (CVS) were a major health problem in all countries, including hypertension (AH), which is a leading risk factor for vascular disasters; acute disorders of cerebral circulation, myocardial infarction. Hypertension makes a significant contribution to the structure of mortality and disability from cardiovascular diseases. The year 2020 changed the decades-old perception of diseases that pose a threat to health on a global scale. The leading clinical symptoms of COVID-19 in patients with background diseases CVS and hypertension are described. An important aspect of COVID-19 is the course of infection in patients with a burdened comorbid background, while the role of hypertension as a risk factor for severe forms is noted. The data obtained will serve to understand the systemic effects, including cardiovascular, that COVID-19 has, which will optimize the provision of timely comprehensive medical care to patients, develop an algorithm for the tactics of management and observation in different periods of the COVID-19 disease.
The use of cholecalciferol in the treatment of bronchial asthma in children
Authors: Turaeva Nafisa , Mukhammadieva Lola , Mamatkulova Dilrabo , Tairova Sakina
Published: August 2023

The results of evaluation of the clinical efficacy of cholecalciferol in the complex treatment of bronchial asthma in children are presented. 60 children with bronchial asthma were examined. All patients were prescribed cholecal ciferol in addition to basic therapy. In all children, the level of the 25(OH)D metabolite was determined in the blood serum. The study of clinical efficacy after treatment showed an increase in the content of vitamin D, in children there was an improvement in the course of the disease: the number of exacerbations per year, the number of night attacks decreased, the length of stay in the hospital was reduced, attacks stopped in a shorter time, the duration of dry and wet cough significantly decreased, it was noted reduction in the duration of shortness of breath, cyanosis of the nasolabial triangle, oral wheezing.
Geometry of foliations of Minkowski spaces
Authors: Artykbaev A. , Narmanov A. Ya. , Ismoilov Sh. Sh.
Published: August 2023

As is well known, foliations of constant curvature and foliations generated by the orbits of Killing vector fields are important classes of foliations from a geometric point of view. The paper studies the geometry of some foliations of the Minkowski space, which arise in a natural way. It is shown that these foliations are foliations of constant curvature. The paper also studies the geometry of some singular foliations generated by the orbits of Killing vector fields.
Perinatal risk of premature birth: New obstetric opportunities
Authors: Shavazi Nargiz , Akhtamova Nilufar , Katkova Nadejda
Published: August 2023

Premature birth (PВ) is a complex medical and social problem associated with solving problems to improve the quality of subsequent life of children born prematurely and associated material and economic costs. The severity of complications associated with prematurity is proportional to the gestational age of premature birth. Currently, obstetricians face two main tasks: detection of threatening premature birth in order to avoid improper interventions and preparation of the fetus for premature birth with the help of adequate and at the same time safe medications. Most maternal complications develop during pregnancy, and many of them can be prevented or cured. These guidelines describe the impact of premature birth on obstetric complications, diagnostic methods and types of correction of various disorders, as well as the results of the study.
Online ESP teaching in non-philology universities: Provided suggestions and proposal
Authors: Ametova (Usmonova) Oyshajon , Mustafoeva Noila
Published: August 2023

It is an undeniable fact that there are different language challenges in every community and the role of language planning is to concentrate on resolving these existing language problems. Uzbekistan also recognizes the importance of solving language issues and advancing the language teaching system in both macro and micro levels that need to develop the language teaching system, particularly improving English language teaching in each stage of education either online or offline.
Retracted Article: Application of correction factors in Rayleigh method in calculation of the fundamental frequency of vibration Cylindrical shell with rectangular cross section
Authors: Scherbakov Alexander , Chulenyov Anatoly , Deniskin Yury , Grigoriev Evgeny
Published: August 2023

This paper has been formally retracted on ethical grounds because the article contains
extensive and repeated instances of plagiarism. The authors are responsible for this
mistake and apologise for it. Request approved by the proceedings Editor and the
Publisher on September 13, 2023.
Thermodynamics of hydrogen sulfide adsorption in Zeolite LiX
Authors: Abdurakhmonov Eldor , Dekhkanova Nigora
Published: August 2023

Sulfur compounds adversely affect the technological process of oil and gas refining, as well as the release of sulfur-containing compounds into the atmosphere, polluting the environment. Oil and gas processing is carried out using microporous adsorbents with high sorption capacity in the purification of gases containing sulfur. This is one of the most efficient methods in oil refining and gas processing. In research work, the adsorption of gases containing sulfur in their composition is carried out in various ways. When determining the formation complex, the main centers of Li-ionic molecules, it was possible to obtain a more accurate idea of the adsorption mechanism at the stages of absorption of hydrogen sulfide molecules into Li-zeolites using a highly sensitive adsorption calorimeter. In our study, in the process of adsorption of hydrogen sulfide on the LiX zeolite, the results of differential adsorption heat, isotherm, entropy, and thermal equilibrium time (thermokinetics) based on obtained in a high vacuum adsorption device are accurately revealed. Based on exact formulas, it was proved how many hydrogen sulfide molecules are adsorbed in the zeolite that died under vacuum conditions.
Technology of fabrication of CdSxTe1-x solid solution on silicon substrate
Authors: Sapaev I. B. , Sadullaev S. , Babajanov D. , Sapaev B. , Umarov A. V. , Pulatov Sh. Y. , Meliziaev O. O. , Daliev K. S.
Published: August 2023

Heterojunction between Si and CdSxTe1-x have been obtained by the method of vacuum deposition of powders of cadmium sulfide and cadmium telluride on the surface of monocrystalline silicon. The optimal temperature regime for the growth of the CdSxTe1-x solid solution on the silicon surface has been determined. The values of the crystal lattice constant and the thickness of the CdSxTe1-x solid solution at the interface of the n/Si – n/CdSxTe1-x heterostructure are calculated.
Obtaining new types of compounds between silicon and cadmium sulfide
Authors: Sapaev I. B.
Published: August 2023

The n+CdS-nCdS-nSi+ structures were obtained and their volt-ampere characteristics at different temperatures were studied. From the dependence of the volt-ampere characteristic it is shown that the sublinear and quadratic section of these structures has a section of current growth with voltage. It is determined that the n+CdS-nCdS-nSi+structures in the current flow direction at low illumination levels work as an injection photodiode. And these structures under laser illumination with λ=0.625 μm and power P=1.2 μW/cm2 have spectral sensitivity 2042 A/W, bias voltage 10 V. At irradiation by white light with energy W=3.6-10μW∙s it has integral sensitivity ≈21 A/I’m (2310 A/W) at bias voltage U=10V.
Leak rate investigation of expanded polytetrafluoroethylene flat gasket
Authors: Mladenov Evlogi , Gospodinov Danail , Radev Rossen
Published: August 2023

This article examines expanded polytetrafluoroethylene (PTFE) flat gaskets used in the industry to seal flange connections that prevent mixing of working fluids and leakage of fluids into the environment. Expanded PTFE gaskets and existing solutions to improve tightness are reviewed. Using test equipment for measuring the mass of gas passed through the gasket per unit time, which is one of the main operating characteristics of the gasket, a comparison of the required contact stress applied to the gasket during installation to achieve the same leakage rates was made. An annular expanded PTFE gasket with locally increased density is presented. Comparative tests were conducted to determine the mass of helium gas passed through the gaskets when changing the density in the sealed area to the inner diameter of the gasket. The results of the tests carried out show an improvement in the sealing ability and indicate a reduction in the mass of passed gas with the application of a lower contact stress on the seal while increasing the density in the area of the inner diameter.
Development of technological process of metal machining from stamping on 5-axis CNC milling machine
Authors: Detkin A. V. , Arkhipova O. V. , Sitnikov S. A.
Published: August 2023

The technological process of compressor working blade production from stamping with minimum allowance for machining of the working part, on 5-axis CNC machine aimed at reducing the units of machine equipment has been developed. The tooling for basing the working part of the blade on the principle of six-point basing adapted to the design of the machine tool is realised. The geometrical parameters of the obtained blade were analysed with its mathematical model by 3D scanning method.
Digital technologies in management tasks
Authors: Belyaeva Marina , Chernikova Elena , Popov Alexey , Nikitchuk Sergey
Published: August 2023

In the context of the digital revolution, all management processes are subject to reforms and optimisation. The public sector, in terms of making managerial decisions at the state head level, as well as federal executive authorities, also forms plans for digital transformation. However, initiating the optimization process in the public sector does not immediately lead to an effective transition to new realities. There are problems slowing down managerial decision-making in the field of digital transformation of the public sector, which affects the effectiveness of achieving strategic planning goals in the state, including in the long term.
Improvement of equipment for top loading of petroleum products
Authors: Kalmykov Boris , Danilov Sergey
Published: August 2023

Transportation of oil and petroleum products is a priority for the development of the country's economy, therefore, the development of fuel-filling equipment that allows to increase the safety of the operator who controls this equipment, as well as the driver of the tank car who works on the tank – opens (closes) filling hatches, and also manually orients the fuel-filling pipe and lowering (lifting) its in the hatch opening of a tanker truck, is an important task. The article offers a description of a new design of fuel-filling equipment for tankers, which allows automating the process of projecting a filling pipe relative to the hatch of a tanker truck when top-loading petroleum products into tankers and increasing measures to protect the driver and operator. This is achieved by introducing additional hydraulic cylinders into the prototype design, which allow moving the filling pipe in the transverse plane of the hatch, as well as lowering (lifting) the filling pipe into the hatch opening for filling petroleum products. Automation of the process is carried out through the use of a video camera, the image from which is transmitted to the operator's control panel. The image comes from a video camera in real time, and in addition to the transverse movement of the pipe, the depth of movement is controlled by the operator on the monitor.
Reducing the thickness of the insulation layer of building walls based on the study of their temperature and moisture regime
Authors: Zubarev Kirill
Published: August 2023

The thickness of the building insulation is calculated with the table values of the moisture of building materials, which is included in the regulatory documents with a margin. The study proposes the method for determining the thickness of the insulation layer using the values of operational moisture. To determine the operational moisture of materials, the equation based on the moisture potential is applied, the solution of which is sought using a discrete-continuum approach. The proposed equation makes it possible to determine the distribution of the moisture potential function in the wall enclosing structure. Thereafter, using the moisture potential scale, the distribution of mass moisture over the thickness of the enclosure for the period of maximum moisture accumulation is determined. The equation for determining the thickness of the insulation layer, in which the calculated value of the operational moisture is explicitly substituted, is derived. An algorithm for calculating the thickness of the insulation layer, taking into account the unsteady-state heat and moisture regime of the building envelope, is given. The application of the proposed method on a wall enclosing structure with insulation from expanded polystyrene boards is illustrated. It was found that the thickness of the insulation can be reduced by 26 mm from 120 mm to 94 mm while maintaining the reduced heat transfer resistance of the building wall. It is noted that the proposed method can be applied in the design of new wall enclosing structures.
Study of the conditional flexibility effect of compressed chord on the overall stability of corrugated beams
Authors: Makeev S. A. , Silina N.G. , Komlev A. A. , Stupin M. A.
Published: August 2023

In this paper, the calculation of cut corrugated beams loaded with uniformly distributed load in the plane of the wall, with a wall height of 333 and 500 mm (54 sizes), chord width from 160 to 400 mm and chord thickness from 6 to 30 mm for general stability in accordance with Building Codes (BC) 294.1325800.2017 is made. A geometric criterion has been defined which defines the boundaries of the load-carrying capacity of Russian corrugated beams between the flat bending form stability and the strength of the normal section under the action of the bending moment in the plane of the wall.
Engineering methodology for calculation of corrugated beams for bending and torsion. Flat bend form stability
Authors: Makeev S. A. , Silina N. G. , Komlev A. A. , Stupin M. A.
Published: August 2023

An engineering design procedure for calculating bending with torsion in corrugated beams, including finding the critical load of general stability, implemented in the commonly used MS Excel spreadsheet and verified in the LIRA-SAPR software package, has been proposed. The method makes it possible to take into account the beams section variability and corrugation parameters, to estimate the loading eccentricity effect, availability of supporting ribs and reinforcements of the compressed chord from the bending plane. Calculation results of particular design solutions for corrugated beams with definition of critical loads at transverse bending are given. Results of test calculation of a bent channel beam with calculation of stress-strain state parameters and its verification with the LIRA-SAP software package are given.
Eurasian transport network as a driver of sustainable transport development in the Eurasian region
Authors: Drozdova Maria , Berezovskaya Irina , Shipunova Olga
Published: August 2023

The article deals with topical issues of sustainable development of the transport and logistics ecosystem in the Eurasian region. The tectonic changes in international relations in 2022 and 2023 led to the development of disintegration processes in Eurasia, which also affected the transport sector. The authors analyze current trends in the formation of a new paradigm of sustainable transport to ensure the transport sovereignty of Russia and the EAEU countries. New challenges pose new challenges in ensuring logistical connectivity of Russia with its international partners, the digitalization of the economy and the introduction of Industry 4.0 technologies create both new opportunities and the need to increase the innovative potential of the industry to ensure its competitiveness at the global level. The study of the prospects of implementing the project “Eurasian Transport Network” to ensure the sustainable development of the transport and logistics ecosystem of the region allows to formulate proposals to improve the regulatory framework to enhance the effectiveness of transport and logistics policy within the EAEU.
Increasing reliability of power supply to electricity consumers
Authors: Isakov Abdusaid , Raxmatov Abdugani , Ochilov Dilshod , Shadmanova Gulchera
Published: August 2023

The article deals with the issues of increasing the reliability of power transformers used in power supply systems for agriculture and water management. Also, the degree of damage to power transformers was studied in terms of the physical and chemical composition of transformer oil, materials were given for assessing the state of insulation by the degree of damage to the insulation of individual units of the power transformer. By measuring the temperature of the most heated part and the chemical composition of the transformer oil, it is possible to determine the degree of wear of the insulation of the power transformer in the operating mode, which allows to increase their service life by 15% and prevent accidents in the networks.
Contemporary climate change problems in Central Asia
Authors: Kulmatov Rashid , Khasanov Sayidjakhon
Published: August 2023

According to the moderate climate change scenario, the direct impact of climate change on irrigated crops, including cotton, wheat, apples, tomatoes, and potatoes, is pro-jected to decrease the yields by 1–13% by 2050. However, the demand for food is expected to increase overall due to the population growth and poverty reduction goals. The rate of climate change in the countries varies. The highest decadal rates of climate change were recorded in Uzbekistan at 0.29°C (1950-2005) and in Kazakhstan at 0.26°C (1936-2005). The climate change rate in Kyrgyzstan and Tajikistan were 0.08°C and 0.10°C, respectively. In these upstream countries, the area of forests and mountain ranges is relatively large, and the possible negative impact of climatic factors is relatively small. Thus, the contemporary problems in Central Asia in the context of climate change are related to a growing scarcity of water resources; uneven distribution of water resources across the countries in relation to the needs; relatively low water use efficiency (especially in agriculture); relatively high population growth rates and intensification of economic processes. If additional resource-saving measures are not taken, the negative consequences of climate change in the region may include an increased risk of water shortages, droughts, and other dangerous hydrome-teorological events that lead to instability of agricultural production and threaten food secu-rity; and particularly the shrinkage of glaciers and therewith one of the key sources of freshwater. Overall, a strategy of action plans on climate change nationally and region-wide is urgently needed, including both adaptation and mitigation measures.