bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of fourier method to study propagation of compression shock wave in pipelines with damper
Authors: Bozorov O. Sh. , Khujaev I. , Aminov Kh. , Khojikulov Sh.
Published: August 2023

The transition problems from one mode of steady flow to another in a pipeline with a constant gradient are considered. The pressure value is set at the inlet to the section, and an air chamber of a certain volume is installed at the outlet. Modeling of the process of compression shock wave propagation in an elementary section of the pipeline was conducted according to the linearized quasi-one-dimensional N.E. Zhukovskymodel, and the damper was considered according to the I.A. Charny model. The problem is solved by the method of separation of variables. It is shown that at an increase in the volume of the damper, the amplitude and frequency of perturbations decrease due to the transient process.
Effect of flow velocity on downstream energy absorbers and velocity coefficient
Authors: Khidirov Sanatjon , Artikbekova Fotima , Azimov Azam , Uljaev Farokhiddin , Donoboyev Jumaniyoz , Nosirov F.
Published: August 2023

As a result of designing an energy absorber in the zone of conjugation of water outlet structures of low-pressure and mediumpressure reservoirs, the stilling basin is not only under the influence of vertical hydrodynamic pressure with a variable value but also the disappearance of stagnation of the stilling basin can also be affected by the hydrodynamic stress arising from the force of horizontal pressure in the energy absorber. The hydraulic jump in the pool junction zone is one of the simplest energy absorbers. To increase the efficiency of this process, it is necessary to improve the hydraulic regime downstream of the water outlet, reshape the interface mode in the stilling basin and on the apron surface, and eliminate flow disturbance, through the construction of special energy absorbers in the stilling basin. These structures exert reactive (accelerating implementation), dislocation (accommodating), and distributed forces on the flow.
Ground behaviour and settlements analysis on tunnelling of shallow-buried metro in Tashkent city
Authors: Miralimov Mirzakhid , Shakhboz Normurodov
Published: August 2023

This paper proposed a calculation method that reflects the process of deformations of the soil mass and subsidence of the ground's surface around the shallow subway tunnels and their study, taking into account the engineering and geological conditions of the construction site on the third line of Tashkent metro. The vertical ground displacements of soil mass and zone of destruction (instability) around the hole of the running tunnel of the metro located at different depths were determined. As a result of the numerical calculations performed, the settlements of the ground's surface were determined during tunneling by the shield method. It was found that the maximum value of the trough of the ground's surface decreases with an increase in the depth of the tunnel. This is because with deep tunneling, settlements are largely determined by the decrease in the vertical pressure of the soil on the tunnel due to the formation of a limited disturbed zone around the tunnel hole.
Study of natural honey of group 04 TN VED: identification examination and physical and chemical properties
Authors: Sayfullayeva Zaynab , Khamrakulov Gofurjon , Rajabov Alisher , Khamrakulov Makhmud
Published: August 2023

For the export of manufactured products, it is necessary to consider its classification according to the commodity nomenclature. The classification code of goods following the commodity nomenclature of foreign economic activity is one of the most common tools used by participants in foreign economic activity to minimize costs and expenses. This code, related to the information indicated in column 33 of the cargo customs declaration for goods, is of great importance since it determines the import (export) customs duty amount. In addition, in the lists of goods approved at the legislative level, in respect of which prohibitions and restrictions are established or tax benefits and exemptions are determined, the goods are determined exclusively by the CNFEA code, and the name of the goods is given only for ease of use. The use of some lists involves the use of both the product code and its name. CNFEA codes are also used when maintaining customs statistics. Also, new code numbers for natural honey according to the commodity nomenclature of foreign economic activity were recommended for the first time based on botanical origin, chemical composition, and consumer properties.
Cement-based concretes with low water requirements
Authors: Akmalaiuly K. , Auesbek S. , Sarsenbaev N. , Sarsenbaev B. , Amanov E.
Published: August 2023

Highways are one of the main elements of the infrastructure and economy of any state. It is well known that the state and level of development of the country's highways directly affect the main economic indicators – the gross national product, the price level, budget revenues, the level of employment, and others. When developing multicomponent binders, as a rule, a systematic approach is used. New binders are considered complex systems consisting of subsystems or elements, each performing its functions. The elements in the system are not isolated from each other but grouped in such a way as to ensure the practicality of the entire system. It should be noted that any changes in a single element or replacing one element with another usually lead to a change in the properties of the entire system. The elements of the system are interconnected, and the more versatile the connections, the more effective the system is. The researcher's task is to correctly select the elements of the system, considering their properties and contribution to the system's overall structure. Of all types of metallurgical slags, blast furnace slags are the most widely used in the production of building materials due to their leading position in the overall balance, their ability to acquire hydraulic properties during rapid cooling, and others.
Non-stationary problem of high earth dam under seismic impact
Authors: Salyamova K. D. , Buriev A. T.
Published: August 2023

The design, construction, and operation of high earth dams on the territory of seismogenic zones of Uzbekistan set the task for researchers to improve the calculation methods and algorithms for various kinds of loads to which the structure is subjected. At present, the application of the dynamic method (a wave theory) to the calculation of an earth structure, i.e., the dynamic stress-strain state of high earth dams under seismic impact within the framework of wave theory, is the most difficult problem in the mechanics of a deformable rigid body. In the example of the operating Charvak high earth dam, the numerical method of finite differences solved the problem of studying the stress-strain state with shear dynamic impact on the base (such as the records of a real seismogram of an earthquake). At the boundaries of the considered finite region of the base, the so-called radiation conditions are set, i.e., diffraction is not considered. The result of solving the non-stationary problem is presented as isolines of displacements and stresses along the dam's body, depending on time. At that, the most vulnerable zones of the considered earth dam were identified.
Improving operation of inter-farm channels
Authors: Sherov Anvar
Published: August 2023

The country's water supply depends mainly on the water resources of the Amudarya and Syrdarya. 80,7 % of the country's water resources are formed in the Kyrgyz Republic and Tajikistan territory. The population of Central Asia is expected to increase by 40 % in the next 20 years. This, in turn, requires more economical use of water and land resources. At present, it is important to modernize irrigation systems, increase their efficiency, automate water distribution processes, and improve the distribution of water to consumers by accurate measurement of internal channels.
River water quality Amudarya in territory of Karakalpakstan
Authors: Sadikova Umida , Usmanov Islom , Rakhimov Nurbek , Usmanov Shavkat , Kudratov Tolibjon , Mirkhasilova Zulfiya
Published: August 2023

The object of the study is the Amudarya River, which is the only source of water supply and domestic water use of the population of the Republic of Karakalpakstan. The studies were carried out because the Republic of Karakalpakstan belongs to the regions of ecological disaster. Therefore, work to reduce anthropogenic pollution's adverse impact on the environment is necessary. The research methods included the sampling of water from the Amudarya River in the established sections of the reservoir according to the seasons of the year for five years, 2016-2020, and the conduct of water analysis following the standard O'zDSt 951:2011 “Sources of centralized domestic and drinking water supply. Hygienic, technical requirements, and selection rules. The indicators of taste, smell, and water color in the studied sections of the Amudarya River correspond to the established hygienic standards. The concentrations of ammonium, nitrates, nitrites, sulfates, chlorides, and total iron in water do not exceed their maximum allowable concentrations. However, the concentrations of turbidity, total hardness, and mineralization of water exceed the permissible values set on them. The maximum turbidity concentrations in water are 39.0 mg/l, total hardness 10.8 mg-eq/l, and salinity 1182.0 mg/l. Based on the work results, monitoring of water quality in the Amudarya River in Karakalpakstan has been improved.

This research aimed to study the long-term quality and assessment of water in the Amudarya River in the territory of Karakalpakstan.
Analysis of pump stations operation mode and measures to improve them
Authors: Kodirov D. T. , Ermanov R. A. , Sherbaev M. R. , Musurmonov M. A.
Published: August 2023

This article presents the data analysis of pumping stations controlled by the Pumping Stations and Energy Departments (PS&ED) of the Republic of Karakalpakstan. Collected data was analyzed according to the number of pumping stations, the amount of water they released, water delivery capacity, annual electricity consumption, and other parameters. The results of the observations and the data compared across districts are presented in tables and graphs. In addition, further measures have been developed to ensure efficient and reliable operation of pumping stations.
Monitoring of green areas in Mirzachul district and its geoecological aspects
Authors: Ruzikulova Oykhumor , Komilova Nilufar
Published: August 2023

The article is devoted to the relationship between public health and the natural environment in densely populated cities. The “Green Space” project enters all areas in the republic. In particular, it is of urgent importance in the mapping of health care and related industries, as well as in geoecological monitoring. The article is dedicated to monitoring the condition of green areas in Gulistan city with the help of remote sensing materials, as well as the analysis and mapping of related geoecological conditions. Medical-geographic mapping is carried out under the influence of natural and social, and technical factors.

The fact that the Syrdarya region and the city of Gulistan are becoming the “hub of innovative medicine” of our country in Central Asia increases the practical importance of this work.
Mathematical models of magnetic circuits of high currents induction sensors for electric power supply systems devices of electric transport
Authors: Amirov S. , Turdibekov K. , Rustamov D. , Saydivaliev S.
Published: August 2023

The magnetic circuits of the developed high currents induction sensors for the electric power supply systems devices of electric transport are researched, analytical expressions of the magnetic flux in ferromagnetic connecting elements and magnetic voltage, the replacement circuit of the magnetic circuit elementary section, as well as mathematical models of the magnetic circuit of the developed sensors, are obtained.
Simulation of process of sand mass transfer over road
Authors: Djabbarov Saidburkhan , Abdullev Khurshid
Published: August 2023

This article presents the results of theoretical studies to substantiate the optimal parameters of sand-proof structures and their influence on the amount of retained sand; to establish the nature of the distribution of air-sand flow when flowing around the roadbed of highways and the speed zone of this flow; the shapes and installation dimensions of sand-proof structures, as well as the nature of the drift of individual parts of the highway with sand. For clarity, the results are presented in the form of illustrations.
Optimization of the set of loading -transportation machines
Authors: Maksudov Z.T. , Mirkholikov S.M.
Published: August 2023

In this case, the road is being restored The results of scientific research on the effective use method and calculation of the used excavator-transport machinery set are being seen. The main indicators considered are the labor cost of loading and transporting soils used in road pavement rehabilitation and the performance of road transport. In this work, the optimal operational parameters of the set of machines used in the construction and repair of the road were determined.
Indicators of the movement of vehicles on the way to the city of Tashkent
Authors: Terpak Andrey , Azizov Qudratilla
Published: August 2023

This article presents the results of research on the indicators of the movement of vehicles on the way to the city of Tashkent. Conclusions are presented on the following indicators: intensity, composition of traffic, speed and density of traffic, road capacity, and load level.
Transverse vibrations of underground pipeline with pinched ends
Authors: Abduvaliev Abdukakhkhar , Abdulkhayzoda Abdulaziz
Published: August 2023

The study of transverse oscillations of extended underground structures from the action of constant harmonic forces is of practical interest. Transverse vibrations of an underground cylindrical structure of finite length under the action of a system of concentrated forces that change according to a harmonic law are considered. The environment surrounding the structure is assumed to be elastic, while the interaction of the “environment-structure” system is studied. When considering the problem, the Fourier method and the results of solving the problem of vibrations of an unbounded cylindrical structure in an elastic medium from the action of concentrated harmonic forces were used. The problem of transverse vibrations of a cylindrical rod of finite length interacting with an elastic homogeneous medium is solved by the method of compensating loads. In this case, the structure is considered a source of waves radiated into space and satisfying the conditions of radiation to infinity. The resulting solution is approximate and reliable within the length of the rod. The analysis of the influence of soil conditions and geometric dimensions on the amplitude of oscillations of an underground structure was carried out according to the graphs of the amplitude-frequency characteristic of the object.
Optimization of physical and mechanical properties of non-autoclaved aerated concrete based on industrial waste
Authors: Shaumarov Said , Gulamov Abdulaziz , Kandakhorov Sanjar , Abdunazarov Jamshid
Published: August 2023

This article presents the results of experimental research on the parameters of aerated concrete porosity strength properties and properties based on industrial waste. The structurally optimal amount of water was determined, reflecting the physical-mechanical, thermal-technical properties of the outer wall structures based on aerated concrete.

The test results were carried out in research laboratories using aerated block constructions with high porosity and optimal composition, and improved technological solutions for autoclaved aerated concrete were developed.

Study of changes in the properties of aerated concrete with the addition of waste quartz sand and steel smelting slag; optimization of aerated concrete composition by mathematical regression method and determination of physical and mechanical properties; the results of the research on automating the calculation of the proposed composition of aerated concrete and the amount of industrial waste according to its brand are given.
Quantitative characteristics of construction and reconstruction of railway sections in Uzbekistan
Authors: Lesov K. S. , Ergashev Z. Z. , Kenjaliyev M. K. , Tadjibaev Sh. A.
Published: August 2023

In this article the results of construction and reconstruction of railway sections to ensure the spatial connectivity of the regions of the country and integration into the global transport space are considered. The use of a systematic approach for selecting the most rational methods of quantitative and qualitative analysis of construction and reconstruction of railway sections is proposed. The basic characteristics and stages of construction and reconstruction of railways in Uzbekistan are given. The indicators of new railway sections construction, construction and reconstruction of railway sections for speed and high-speed trains movement during the period of Uzbekistan’s independence have been analysed. When analysing the indicators the quantitative estimation by length, total cost and cost per kilometre of large investment projects, realized during Uzbekistan's independence years have been used.
Creation of transport and logistics clusters on railway networks
Authors: Mukhamedova Ziyoda , Ibragimova Gulshan , Khudayberganov Sakijan , Bashirova Alfiya , Kayumov Shokhrukh
Published: August 2023

The development of logistics terminals and their placement on the railway network, which involves their integration into transport and logistics clusters, will significantly reduce logistics costs, thanks to the optimal technology for the movement of goods, and also contributes to active import substitution and the level of growth in the competitiveness of goods and services. Clustering, which is being given great attention by the Government of the country today, will allow solving some issues of territorial balance of production concentration, increasing the share of high-tech industries, avoiding dependence on trade in resources, increasing the added value of goods, increasing economic growth rates. Modern Uzbekistan has huge transport potential and unique opportunities to meet the needs of the country in the movement of both goods and passengers in all directions by all possible modes of transport through the use of available transit resources. The article analyzes the sectoral structure of the industry of Uzbekistan, shows the existing clusters of the agricultural sector of the republic. The methods of assessing the level of cluster development in the context of the regions of Uzbekistan are described. Paired correlation analysis was used to determine the presence and type of relationship between the studied factors. As a result, the regions of Uzbekistan in terms of the placement of freight infrastructure on railways in order to create potential transport and logistic clusters were grouped depending on the indicators of socio-economic and infrastructural development.
Investigation of the sorption method of processing molybdenum-containing raw materials to extract rare metals
Authors: Bozorov A. N. , Negmatov S. S. , Erniyozov N. B. , Subanova Z. A. , Sultonova I. Q.
Published: August 2023

The article investigates the sorption method of concentrating rare metals on various sorbents (brands “Purolight”: A-100, A-170, A-172 and BO-020) and determines the optimal conditions for their extraction. It is shown that the extraction of molybdenum on the sorbent “Purolight A-100” was 98%. The proposed sorption mechanism consists in the formation of molybdenum complexes with functional phosphor basics and sulfate groups of sorbents. Sorption of rhenium on the Purolite A-170 sorbent was 93%. Sorption of rhenium on the sorbent BO-020 is described by the Langmuir equation with a maximum static exchange capacity of 94%. Based on the sorption and desorption kinetics of molybdenum and rhenium on various ion-exchange sorbents, it was shown that the sorption of molybdenum and rhenium proceeds most efficiently on low-basic anion exchangers A-100 Mo and A-170, respectively, and after double recleaning of the “rough” rhenium concentrate, ammonium rhenium of qualification was obtained AR-0.
Automated technique for designing the basic foundations of a clothing drawings
Authors: Abdukarimova Mashkhura , Mahsudov Shohruhmirzo , Nuriddinova Rokhilakhon , Asadullayeva Nodira
Published: August 2023

The article considers the process of formalisation of the automation of the design of garments by introducing the author’s method of constructing the basic basis of the drawing of shoulder garments. In order to develop the curves of the structure, an analytical method of design using spline interpolation by third-order polynomials is proposed.
Numerical simulation of combustion processes
Authors: Latipov Nusratilla , Abduraimova Dilbar , Ibragimova Zaytuna , Otakhonov Makhsud , Hamdamov M.
Published: August 2023

In this paper, we propose a numerical method for solving the problem of the propagation and combustion of a methane jet in an axisymmetric satellite air flow. Within the framework of the modified turbulence model and the Arrhenius law, mathematical and numerical models of the problem of a turbulent axisymmetric methane jet in an infinite cocurrent air flow at a finite reaction rate have been developed. By introducing functions and generalized Schwab-Zel'dovich functions, as well as the stream function, ten differential equations for the conservation of substances are represented by differential equations equivalent to them. The equations of the turbulent boundary layer of a multicomponent gas for an axisymmetric jet are transformed with the transition to dimensionless variables and the introduction of a stream function. The dimensionless equations of the turbulent boundary layer of reacting gases in von Mises coordinates are used for modeling. For the numerical solution of the combustion problem according to the Arrhenius law, an implicit finite-difference scheme was used, which provides the second order of approximation accuracy in longitudinal and transverse coordinates. This made it possible to significantly reduce the calculation time as a result of using a large calculation step for the longitudinal coordinate. In connection with the nonlinearity of the equations of conservation and transfer of substances, an iterative process was organized. Some results of the computational experiment are presented. Comparison of the results of calculating the change in the temperature of the axial flow according to the turbulence models modified by k − ε and Prandtl with experimental data. The adequacy of the results was verified by the implementation of the laws of conservation of mass, momentum and total enthalpy, as well as by comparing the results with experimental data from other authors with the largest 5% deviation. This means that the previously presented algorithm and calculation program can be used for practical purposes. The results obtained with both turbulence models were compared with experimental data. Analyzing the results, one can notice that the k − ε model coincides more qualitatively with the experiment than the Prandtl turbulence model.
Analysis of vegetation changes in land area of Syrdarya region using GIS technology and remote sensing data
Authors: Ruzikulova Oykhumor
Published: August 2023

This article presents a map of vegetative changes in the Syrdarya region based on remote sensing data. Landsat 8 and Landsat 9 satellite images were used for analysis during the vegetation active period. The study examines the vegetation state of the selected area from 2000 to 2022 and analyzes the changes. The Normalized Difference Vegetation Index (NDVI) was calculated using ArcGIS 10.6 software and documented sequentially. The number of color-coded pixels on the map indicating the health and unhealthiness of the crops and the areas they occupy was determined through NDVI analysis. The study revealed a decrease in the vegetation layer in the Syrdarya region, and the reasons for this phenomenon were discussed. The article demonstrates the usefulness of remote sensing in analyzing vegetational changes over time and its potential applications in monitoring the health and productivity of crops in different regions. Overall, this research is valuable for developing strategies to mitigate the impact of vegetation loss in the Syrdarya region and similar regions facing similar challenges.
Influence of irrigation technology with use of technical means on development and yield of cotton
Authors: Atajanov A. U. , Bekchanov F. A. , Usmanov N. K. , Asrarova М. K. , Akhilbekov N.
Published: August 2023

Currently, the intensification of agricultural production and the development of irrigated agriculture requires the search for solutions for the rational and economical use of irrigation water, the widespread introduction of new, improved water-saving technologies, and technical means into production, which directly positively affects the growth, development, and yield of cotton. This article is devoted to the influence of irrigation technology with technical means on the irrigation rate, growth, development, and yield of cotton.
Monitoring of rolling bearing failures as result of acceleration
Authors: Bekchanov F. A. , Atajanov A. U. , Usmanov N. K. , Babajanov L. K. , Balabanov V.
Published: August 2023

The article discusses modern methods of diagnosing and technical diagnostics of irrigation pumping units to ensure reliability during operation. Using new designs of pumping power equipment and developing new operating modes provide for improving the mode of pumps based on improved diagnostics, significantly saving operating costs. Together with this provides detection, control, and prediction of multi-stage failure of the rolling bearing by monitoring the vibration trends of the centrifugal pump unit during operation.
Contactless wide-range ferromagnetic high-current converters for monitoring and control systems in the electric power industry
Authors: Plakhtiev Anatoliy , Gaziev Gayratjon , Doniyorov Odil , Muradov Khayot
Published: August 2023

The paper shows that the impossibility of breaking the current circuit for the production necessity of temporarily switching on electrical measuring instruments, large power losses on shunts, and the need to obtain quick information about the quality of the functioning of technological processes have led to the widespread use of non-contact conversion and measurement of high direct currents in circuits without breaking them. Light detachable wide-range stationary and portable non-contact transducers and meters of high direct currents are not yet mass-produced. In this regard, it is expedient to develop and study non-contact converters and meters of high direct currents, which are distinguished by a wide range of converted currents, small dimensions and weight, increased accuracy, and sensitivity of electric power facilities. The questions of sensitivity of magneto-modulation non-contact transducers are considered. The expression for the optimal static characteristic of the developed magneto-modulation non-contact transducer is determined and analyzed. Its maximum deviation from the calculated value does not exceed 6%. The expressions for the current, average sensitivity, and sensitivity regarding the magnitude of the excitation of a magneto-modulation non-contact transducer are obtained and investigated. In this case, the maximum sensitivity of the transducer reaches a value of 0.425 with an optimal excitation value of 1.65. It is recommended to take the allowable limit of the input value of the converter to be less than one. Its input value must be taken equal to 0.7. The developed magneto-modulation non-contact transducer has an increased sensitivity due to longitudinal modulation. It can be widely applied in control and management systems in melioration and irrigation, water supply, industry, metallurgy, railway transport, science, technology, GIS technology, and, in particular, digital coverage and database visualization, and as well as for checking electric meters at the place of their installation for non-contact control of direct, as well as alternating currents.
The Evaluation of PVD Coated High Speed Steel End Mill
Authors: Lee Sangseog , Mirzaev Bakhadir , Eshchanova Guzal , Ergashev Ismoil
Published: August 2023

To enhance the cutting performance of high speed steel(HSS) end mill, single and multilayer coating is applied on the substrated of the HSS end mill. Coating material reduces cutting force and enhances resistance against abrasive wear. This paper presents the physical vapour deposition(PVD) coating technology and the machinability of PVD coated HSS end mill. The performance of coated HSS end mills are fifteen times better than uncoated HSS end mill on proposed cutting conditions. The TiAlN monolayer coated end mills(futura nano coating) are better than those of multilayer coated end mills(futura coating) on machined surface and tool wear.
Improved installation for determining antifriction properties of materials
Authors: Eshkobilov Xolikulovich Olim
Published: August 2023

The paper presents an improved installation and method for determining friction-electro-thermal properties -friction coefficient, temperature, and value of electrostatic charge in the friction contact zone of machine-building composite wear-resistant-antistatic-thermal conducting polymeric materials during interaction with raw cotton. The existing methods and installations working at the frictional influence of polymers and composite materials with raw cotton have been studied. The general disadvantages of existing devices have been revealed, particularly the impossibility of investigating the frictional properties of materials with cotton.

Theoretically and experimentally substantiated principle technological scheme of antifriction interaction of polymeric materials with cotton, where the polymeric material under study is represented as a flat disc rotating in a horizontal plane on which surface cotton is pressed along the normal using a piston in a bottomless box having a cylindrical lateral surface, which leads to minimization of lateral pressure. The developed scheme of antifriction interaction allows maximum imitation of working conditions of working elements of real machines. And also, the antifriction and physical-mechanical properties of composite polypropylene and polyethylene materials filled with organomineral ingredients determined by the developed method and improved installation -tribometer are given.
Main parameters of manure sealer
Authors: Chuyanov D.Sh. , Mamatov F.M. , Shodmonov G.D.
Published: August 2023

The purpose study is to substantiate the main parameters of the slitter for embedding manure in the soil. A slitter has been developed for lifting the formation, forming a gap along the manure strip lying on the surface of the field, pushing it into the gap, and leveling the gap with soil. The slitter includes a rack, large and small cheeks connected to a soil-supporting plate, made with an increasing slope from the bottom to the top towards the small cheek and adjacent to the soil-supporting plate. A window is made in the big cheek for the passage manure. The large cheek is somewhat pushed forward relative to the soil-bearing plate, and its front face is pointed. It is established that when planting fertilizers, the following operations must be carried out: lifting the formation, forming a gap along the manure strip lying on the surface field, pushing the latter into the gap, and leveling the gap with soil. The most acceptable for lifting the formation and the formation of a gap is the working bodies dump type. The following optimal values of the parameters slit are established: the large removal cheek is 710 mm, the width is 200 mm, and the length and height window are 550 and 250 mm, respectively.
Construction of experimental inter-operational conveying device
Authors: Khusanov Kakhramonjon
Published: August 2023

The results of the construction of inter-operational conveying devices for the creation of an automatic line for the mechanical processing of a leather semi-finished product between several technological machines for leather processing are considered in the article. At the same time, on this line, all processing machines must be feed-through ones. The dimensions and principles of operation of the mechanism of conveying devices are shown. The main mechanisms of this conveyor are string conveyors, cutting and pressure rollers. The results of the experiments are presented. The task of this proposed conveying device is to increase labor productivity by automating the process of transportation and partial straightening of the sheet material during transportation, as well as communicating the desired speed to the sheet material after partial straightening. It is shown that with the wrong choice of the diameter of the work rolls, the design of the machine, changes in the angular speed of the spreader shaft affect the quality of the extraction and straightening of the folds of the leather semi-finished product.
Scientific and methodological substantiation of measures for environmental management of upstream area Tupolangsky waterworks
Authors: Begmatov Ilkhom , Bekmirzaev Gulom , Durdiev Oraz
Published: August 2023

For the 8.2 hectares of the Tupolang hydroscheme near the dam, the measures for its landscaping with the help of a drip irrigation system have been developed. The source of irrigation is infiltration water from the old riverbed. After natural filtration, the water is clear, without mechanical impurities, with a salinity of 0.2 g/l and a flow rate of about 50 l/s. At the end of this pipe, the head is 4 MPa, which eliminates the traditional device of the pumping station to create the required head in a closed irrigation network. This allows the application of these irrigation systems without a pumping station and water treatment. The article presents the initial data for the calculation of drip irrigation:

1. Soils are typical gray soils, non-saline, medium loam by mechanical composition;

2. Groundwaters are at a depth of > 3 m;

3. Mass volume of soils is 1.4 t/m3;

4. Marginal field moisture capacity (MWC) - 28 %;

5. Ultimate moisture capacity is accepted at 85 % of FWP and makes 23.8 %. And most importantly, such irrigation saves water resources.
Telomerization reaction of ethylene with ethanol
Authors: Abdullaev J. , Nurmanov S. E. , Mirkhamitova D. Kh. , Kodirov O. Sh.
Published: August 2023

The research's main aim is to synthesize saturated alcohols containing four or more carbon atoms in the chain from ethylene and ethanol, which are products of natural gas processing. During of investigation, isobutyl and isohexyl alcohols were synthesized, and the optimal conditions for the process were determined. The dependence of the product yield on various factors has been studied.
Water adsorption on acetylene black carbon
Authors: Khudoynazarov F. , Nurmanov S. , Yakubov Yu.
Published: August 2023

Differential heat, isotherm, thermokinetics, and entropy of water adsorption on the black carbon were studied by the adsorption-calorimetric method at 303 K. The adsorption mechanism, type, and number of formed ion-molecular complexes were determined. Thermokinetics of adsorption on the black carbon and the law of migration of exchange cations were determined, and the adsorption energy of gases and vapors was calculated. The adsorption isotherm is described by the two-and three-dimensional mathematical equations of the volume-saturation theory of micro-pores (TVSM).
Study of heteronuclear complexation in Fe(II)-Fe(III)-Mn(II)-CH3COOH-H2O system
Authors: Zhorobekova Mairambu , Mametova Altynai , Miraminzoda Farida
Published: August 2023

Heteronuclear complexation in the Fe(II)–Fe(III)-Mn(II)CH3COOH-H2O system at 318 K and ionic strength of 1.0 mol/l was studied by the Clark-Nikolsky oxidation potential method. The formation of complexes of the composition: [FeL(H2O)5]2+; [FeLOH(H2O)4]+; [FeIIIМnIIL(H2O)3]4+; [FeIIIМnIIL(OH)2(H2O)9]2+; [FeL(H2O)5]+; [Fe(L)2(H2O)4]0; [Fe(L)(OH)2(H2O)3]-, two of which are heteronuclear. The conditions for forming and dominating coordination compounds in an aqueous solution are established.
Some structural aspects of heat resistant plates from brick fight
Authors: Zakiryo Buzrukov , Abdurahmonov Adkhamjon
Published: August 2023

The article describes some aspects of analyzing structures of heat-resistant reinforced concrete slabs designed to cover the surface of brick ovens. Fragments of crushed stone from bricks were obtained as the main filler in manufacturing heat-resistant facing slabs. The plate is reinforced for strength, and its protective zone is offset to the neutral axis to protect the armature from temperature. Contains analytical data on scientific research over the years, problems, conclusions about the need for research, the results of experimental tests, and the results of studies of porosity and structural aspects of the developed design of heat-resistant plates. This heat-resistant reinforced concrete slab has passed natural tests in brick kilns of brick factories in the Namangan and Andijan regions of the Republic of Uzbekistan. Conclusions are made about the application of the obtained research results in production.
Topic "Methods of connecting three-phase electric circuits" and its advantages of interdisciplinary training
Authors: Tulkinov Muhammad
Published: August 2023

This article highlights the topic "Connection of three-phase electrical circuits in a star and a triangle", which is an interdisciplinary and interconnected circuitry with general patterns, features, and issues of the formation of theoretical and practical knowledge.
Study of the operational properties of the bolster of a freight car bogie
Authors: Valieva Dilmira , Yunusov Salokhiddin , Tursunov Nodirjon
Published: August 2023

Different optimal designs of bogie bolster for model 18-100 freight car are examined in the article. There is an analysis of existing bolster designs. Full-fledged fatigue tests by the method specified in GOST 32400-2013 are carried out on the stand designed for dynamic strength tests. The values of experimental studies on the stand were compared with the calculated ones, with maximum loads from 735 to 755 kN. The best results were observed at a maximum load of 745 kN, and the beam lost its bearing capacity at 6.182 million cycles, which is 39% more than the required strength index. The minimum cycles before cracking and before the loss of bearing capacity of the freight railway bogie bolster beam were established.
Choosing of rational periodicity of engine crankcase oil changing taking into account energy-saving properties of oils
Authors: Alimov Muzaffar , Riskulov Alimjon , Nurmetov Khurshidbek
Published: August 2023

It is known that reducing friction losses and, consequently, wear is the most important function of engine crankcase oil. Many oil manufacturers add additives to the oil composition - thickening and friction modifiers. Achieving a rational periodicity of crankcase oil changing generally reduces the operating consumption of oil, the cost of which accounts for a significant share of the total cost structure of operating costs. The developed method for evaluating the energy-saving properties of the researched three grades of oil by viscosity-temperature characteristics allows for reducing the cost of conducting special research. The viscosity value's dependence on the temperature range from 20 to 100 ° is experimentally established. This work presents part of the research results to justify the choice of rational changing periodicity of diesel engines’ crankcase oil, considering the energy-saving properties of oils. During operation, it is also necessary to comply with the requirements for preserving the recommended grades of fuel and lubricants, observing their use and safety modes, and a reasonable oil level in the crankcase.
Optimization of the operation of the mechanism of the cross planer
Authors: Mamayev Sherali , Avdeeva Anna , Ablyalimov Oleg , Nigmatova Dilnoza
Published: August 2023

The subject of the research is the optimization of the mechanism of the cross planer. In the article, on the basis of the condition of closed contours, the equations of the projection of the links on the corresponding coordinate axes are compiled. A functional relationship has been established between the kinematic parameters characterizing the movement of the input and output links of the mechanism. The obtained numerical calculations are presented in the form of graphic dependences. The aim of the work is the optimal metric synthesis of the mechanism of a cross-planer, with parametric restrictions. The conclusions obtained in the article can be used to improve and design modern technological equipment with mechanisms similar to the mechanism of a cross-cutting machine.
Influence of silica-containing additives on structure formation of composite cement binder for non-autoclaved aerated concrete
Authors: Tsoy Vladimir , Abdullaeva Djamilya
Published: August 2023

The article presents the results of a study of the effect of silica-containing fillers on the structure formation of a composite cement binder. Obtaining results allows the use of active fillers in cement sources, which allows to reduce the proportion of binder without loss of density, which is the result of using the resource of energy-saving research technologies in the field of building material.
Investigation of the period of natural oscillations of the embankment on approaches to bridges
Authors: Mekhmonov Mashkhurbek , Makhamadjonov Shukhratjon
Published: August 2023

The article analyzes the designs of existing transition sections on the approaches to bridges and shows a decrease in the natural oscillation period of the subgrade as a result of strengthening the transition sections with the developed design solutions.
Mathematical simulation of process of curing auto-filler based on unsaturated polyester resin
Authors: Abdullaev O. G. , Toshmirzaev Yu. U. , Mirzaev T. S. , Umarov A. V.
Published: August 2023

In this article, with the help of mathematical modeling of the curing rate, the influence of factors directly affecting the curing processes of an auto-filler prepared based on unsaturated polyester resin was studied: the concentration of the accelerator, hardener, and temperature. When modeling the process, the accelerator, hardener, and temperature concentrations were taken as the initial (input) parameters, and the curing rate of the auto-filler at various temperatures was taken as the final (output) parameter.
Mathematical model of collision process of seeder coulter with stones
Authors: Igamberdiyev Asqar , Alikulov Saydilla , Usmanov Elyor
Published: August 2023

The article presents the results of scientific-theoretical research on the development of mathematical modeling of the process of collision of the seeder coulter with stones and the introduction of new technologies for sowing seeds of agricultural crops on stony soils to improve the performance of seeding units.
Complex formation of molybdenum (V) with 1-phenyl-2,3-dimethylpyrazoline-5-thion in 4 mol/L HCI medium at 273-338 K
Authors: Egamberdiev A. Sh. , Azizkulova O. A. , Jurabekov U. M. , Khamidova F. R. , Abdulkhaeva M. I.
Published: August 2023

The process of complexation of molybdenum (V) with 1-phenyl-2,3-dimethylpyrazolin-5-thione in a 4 mol/l HCI medium in the temperature range 273-338 K was studied by the potentiometric method. It has been shown that the reduced form of the 1-phenyl-2,3-dimethylpyrazolin-5-thione molecule is involved in the complex formation reaction. Using the data of potentiometric studies, the change in the energy value (ΔE) of the (NH4)2[MoOCI5]2-1-phenyl-2,3-dimethylpyrazolin-5-thione-4 mol/l HCl system, the equilibrium concentrations of 1-phenyl-2,3-dimethylpyrazolin-5-thione, formation function values, step and general stability constants of oxochloro-1-phenyl-2,3-dimethylpyrazolin-5-thione complexes of molybdenum (V) formed in HCl solutions in the temperature range 273-338 K. The stability constants of oxochloro-1-phenyl-2,3-dimethylpyrazolin-5-thione complexes of molybdenum (V) were refined using the Bjerrum graphical method. The temperature coefficient method was used to estimate the thermodynamic functions of complex formation processes in the (NH4)2[MoOCI5]-1-phenyl-2,3-dimethylpyrazolin-5-thione - 4 mol/L HCI system. The domains of dominance and the maximum yield of each complex form are found. It has been established that in the studied system (NH4)2[MoOCI5]-1-phenyl-2,3-dimethylpyrazolin-5-thione - 4 mol/l HCI during the interaction of the MoO3+ ion with 1-phenyl-2,3-dimethylpyrazolin- 5-thione in the entire temperature range of the experiment forms 5 mononuclear coordination compounds containing from one to five coordinated molecules of the organic ligand. It was found that with increasing temperature, the values of the general stability constants of coordination compounds decrease, which confirms the exothermicity of the reaction of formation of oxochloro-1-phenyl-2,3-dimethylpyrazoline-5-thione compounds of molybdenum (V). The experimentally found values of enthalpy made it possible to assume that the reaction of complex formation between the MoO3+ ion and the molecules of nitrogen- and sulfur-containing heterocyclic 1-phenyl-2,3-dimethylpyrazolin-5-thione proceeded exothermically spontaneously. Based on the above equations, all calculations were carried out using a computer in the Excel programming language, Borland Delphi, Windows 7 operating system.
Solving problem of early diagnosis on basis of framework neurons
Authors: Muhamediyeva D. T. , Sotvoldiev D. M. , Jurayev Z. , Khasanov U. U.
Published: August 2023

The program’s structure for analyzing optic nerve images is based on methods and algorithms for quantitative assessment of pathological changes in the vascular system of the retina. Scale changes, shifts, twists, angular changes, and partial stability of other neural networks have been shown to be achieved.
Research of hydroabrasive wear resistance of organomineral coatings depending on operating environment conditions
Authors: Ziyamukhamedov Javohirbek , Nafasov Jasurbek , Rakhmatov Erkin , Tadjikhodjaev Zakirkhodja , Djumabaev Alijon
Published: August 2023

The critical importance of corrosion protection puts it forward as a leading economic and applied problem for all countries. Costs associated with corrosion, even in developed countries, range from 1 to 3.5 per cent of gross domestic product (GDP). This article discusses issues related to the development of the composition of anti-corrosion materials from organo-mineral heterocomposites for use in structures for the storage and transportation of various aggressive liquids. Experiments were carried out in real operating conditions of equipment for storage and transportation of oil and oil products. Based on the study of the composition of associated water, taking into account the influence of mechanical impurities, the phenomena occurring on the surface of the metal were studied and the optimal composition was selected, the use of which will increase the service life.