bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic analysis of an orthotropic viscoelastic cylindrical panel of variable thickness
Authors: Mirsaidov Mirziyod , Abdikarimov Rustamkhan , Normuminov Bakhodir , Khodzhaev Dadakhan
Published: June 2021

The intensive development of the modern industry is associated with the emergence of a variety of new composite materials. Plates, panels, and shells of variable thickness made of such materials are widely used in engineering and machine building. Modern technology for the manufacture of thin-walled structures of any configuration makes it possible to obtain structures with a given thickness variation law. Such thin-walled structures are subjected to various loads, including periodic ones. Nonlinear parametric vibrations of an orthotropic viscoelastic cylindrical panel of variable thickness are investigated without considering the elastic wave propagation. To derive a mathematical model of the problem, the Kirchhoff-Love theory is used in a geometrically nonlinear setting. The viscoelastic properties of a cylindrical panel are described by the hereditary Boltzmann-Volterra theory with a three-parameter Koltunov-Rzhanitsyn relaxation kernel. The problem is solved by the Bubnov-Galerkin method in combination with the numerical method. For the numerical implementation of the problem, an algorithm and a computer program were developed in the Delphi algorithmic language. Nonlinear parametric vibrations of orthotropic viscoelastic cylindrical panels under external periodic load were investigated. The influence of various physical, mechanical, and geometric parameters on the panel behavior, such as the thickness, viscoelastic and inhomogeneous properties of the material, external periodic load, were studied.
The effect of shale mineral powder on the strength of asphalt concrete
Authors: Buriyev Shuxrat , Davranov Shoxrux , Kuchkarov Yokub , Saydakberova Iroda
Published: June 2021

In the article, work has been done to obtain shale mineral powder based on local raw materials and develop technologies to improve the physical and mechanical performance and durability of asphalt concrete, thereby increasing the physico-mechanical performance and durability of asphalt concrete, the density of fine-grained hot dense asphalt mix with shale mineral powder. The water absorption index of the asphalt concrete mixture decreases, the strength increases, and the transport performance of the road improves.
Compressive strength properties of hyper-compacted concrete
Authors: Khasanov Bakhridin , Tillaev Alisher , Mirzaev Timur
Published: June 2021

The most important property of a concrete mix is concrete workability, i.e., the ability of the mixture to spread and take a given form while maintaining solidity and uniformity.

The main influence on the workability of the concrete mixture is exerted by water consumption and, in part, cement consumption. Workability is determined by the mobility of the concrete mixture at the time of filling the mold and plasticity, i.e., the ability to deform without breaking the continuity.

In the process of vibrating and pressing the concrete mixture placed in the mold, the total volume of the mixture changes until the pressure is balanced by the resistance forces. Deformation of concrete mix or, more precisely, freshly laid concrete with any compaction methods, including vibration compaction, is divided into elastic (reversible) and residual (irreversible). Residual deformations during vibration compaction occur as a result of water squeezing out and redistribution of aggregate fractions.

Permanent deformation is part of the total. Its value at the same composition of the concrete mixture depends on the shape and size of the pressed sample. At the same time, it is noteworthy that after reaching a certain pressure, only elastic deformations will be characteristic of the freshly laid concrete mixture. So, A.D. Nikitin, in the course of the experiments, found that at a pressure of 2.2 MPa, the elastic moduli of the components of the concrete mixture have the following values: for cement paste - 0.16 · 104 MPa, aggregate - 4.5 · 104 MPa and air - 3 MPa ... After reaching a static pressure of 2.2 MPa, the compressible mixture showed only elastic deformation. This indicates that by the time the specified pressure was reached, the relative movement of the aggregates had ended, i.e., they are located most compactly.
Development of high-strength concrete with the addition of a universal superplasticizer
Authors: Barkhanadzhyan Aida , Riskulov Alimjon , Karimov Maksud , Khakimov Ravshan , Ibragimov Botir
Published: June 2021

Automobile roads perform a particularly important, responsible function in the movement of every automobile, transport equipment. The quality of automobile roads determines the reliability of road construction and automotive equipment, the resource of their work, and, most importantly, ensuring traffic safety. However, the construction of roads and construction methods with the expiration of a certain time undergo significant changes associated with the intensive development of road transport, road construction equipment, an increase in the intensity and flow of traffic. In this regard, there is a need to build high-quality roads and cover roads with durable concrete, which can be achieved by upgrading with composite chemical additives in the composition of concrete - a modernized superplasticizer. The object of this work is a superplasticizer for producing wear-resistant concrete. The introduction of a superplasticizer into the composition of concrete makes it possible to obtain especially strong concrete with an increased service life, which in turn will significantly reduce material costs for raw materials, repair work, and labor resources. The purpose of this study is to obtain a highly effective superplasticizer and particularly durable wear-resistant concrete for road surfaces. To achieve this goal, it is necessary to solve the following tasks:

prepare raw materials, develop an optimal component composition and obtain a superplasticizer;

in laboratory conditions to obtain a prototype of concrete;

determine the quality indicators of the resulting concrete by GOST;

to conduct pilot tests for implementation in production.
Influence of temperature on the properties of fireproof materials
Authors: Budykina Tatiana , Anosova Yevgenia
Published: June 2021

The results of experimental studies of the behavior of fireproof materials of Russian production – OGNEZA-LTU, OGNEZA-M-KOR, OG-NEZA-M-KOR (NG), «OGNEBAZALT» PMBOR, OGNEZA-GT under thermal action are presented. Research method – synchronous thermal analysis TG/DCS/dDSC, including differential scanning calorimetry (DSC) and thermogravimetry (TG). Experimental conditions on the NETZSCH thermal analyzer: measurement mode – TG/DCS/dDSC; heating rate: 20 °C /min; heating – up to 1000 °С; atmosphere – N2. The rates of weight loss of the investigated fire-retardant materials have been studied. A high rate of weight loss was established for the OGNEZA-LTU samples (20.5 %/ min at 335 °C) and OGNEZA-GT (11.9 %/min at 369 °C); low – OGNEZA-M-KOR (NG) – 1.7 %/min at 349 °C, OGNEZA-M-KOR – 6.1%/min at 341 °C, «OGNEBASALT» PMBOR - 3.5 %/min at 388 °С. Time intervals of weight loss were determined: all test samples had maximum weight loss in the range of 15-20 minutes. The temperature ranges of the maximum rate of weight loss were determined: 349 - 388 °C. The best heat-resistant properties were shown by OGNEZA-M-KOR (NG), «OGNEBASALT» PMBOR, OGNEZA-M-KOR. It is proposed to consider the revealed properties when using fire retardant materials for the constructive fire hazard of civil and industrial facilities.
To the determination of non-washable speed in the channels bed consisting of disconnected soils
Authors: Samiev Luqmon , Rakhimov Qudratjon , Ibragimova Zaytuna , Allayorov Davron
Published: June 2021

This article analyzes the factors that influence the deformation process in the channel. When assessing the deformation process in channels consisting of disconnected soils, the method for determining nonwashable speed was analyzed, taking into account the trapezoidal shape of the channel, and, based on laboratory studies, a dependence was proposed for determining the non-washable speed. The values of the proposed dependencies are compared with the calculated values of the formulas of I.I. Levi, C.E. Mirtskhulava, V.A. Velikanova, B.I. Studenichnikov and A.M. Latyshenkov and obtained positive results. The proposed dependencies for the determination of non-washable speed are improved, taking into account turbulence and the laws of velocity distribution over the stream's depth. In the experimental researches, were used sand particles with different diameters d ≤ 0.315mm; 0.315mm < d ≤ 0.63mm; 0.63mm < d ≤1.25mm 1.25mm < d ≤ 2.5mm 2.5mm < d ≤ 5.0mm. Based on the analysis of the experimental data, the coefficients are as follows: η1 = 1.41 for the bottom of the channel and η2 = 1.52 for side slopes. The reliability of the results is justified by comparing the proposed calculation method with a study of other authors. Based on the research, constructed a plot of the velocity distribution and the depth of the stream. In these diagrams, preservation of the change in velocity along the depth of the flow was observed under various modes of motion. In all experiments, a process was observed-the smallest value of the flow velocity at the bottom and the highest at a depth of (0.8–0.9) h from the water level.
Numerical Simulation of Stress and Strain Behavior of Foundation Soil under Compensation Grouting
Authors: Bestuzheva Alexandra , Chubatov Ivan
Published: June 2021

To prevent the development of settlements and heave-up of facilities, the compensation grouting technique is used. The article reports the data of numerical simulation of the compensation grouting process as illustrated by the physical experiment performed by Luca Mazini, Ph.D. from La Sapienza Rome University (Rome, Italy). Simulation is performed with the JulyS program developed by the article authors for the ECM. The program implements the finite element method in a three-dimensional approach with Professor L.N.Rasskazov’s non-linear “energy” soil model. Different simulation of supplementary volume arrangement in the sandy soil under grouting in the finite element method approach is reviewed. The numerical simulation data are compared with the field experiment.
Transfer equation for the strain rate tensor and description of an incompressible dispersed mixture (incompressible fluid) by a system of equations of dynamic type
Authors: Yuldashov Askar , Abdisamatov Otabek , Abdullaev Behzod , Dustova Salima
Published: June 2021

It is known that the application of the vector operation rot to the equations of hydrodynamics leads to the Helmholtz-Friedman equation for a vortex. A dispersed mixture, tensor transformations are used, in a certain sense generalizing the vector operation rot, which gives more than one, a couple of equations. One of them describes the transfer of vorticity is the well-known Helmholtz-Friedman equation. The second equation was obtained for the first time, and it describes the transfer of the strain rate tensor. Any tensor decomposes into symmetric and antisymmetric parts. By definition, the symmetric part of the tensor U is the strain rate tensor. The antisymmetric part of U is a tensor whose components are related in a known manner to the pseudovector angular velocity.
Results of full-scale and laboratory studies of the spillway of HPP No. 2
Authors: Khusankhudzaev Ulmas , Kadirov Odil , Jakhonov Azizjon
Published: June 2021

In the article, based on the results of field measurements and calculations, recommendations are given for determining the roughness coefficient of the channel of the spillway. Based on the analysis of the literature and field research data, it was recommended to take the roughness coefficient of the channel of the spillway (canal) equal to n = 0.02 - for areas with steep slopes and without sediment deposits, and in areas with the worst condition of concrete surfaces and sediment deposits, take n = 0.0225. According to the results of field surveys of the canal, it was found that the hydraulic regime at the turning section No. 2 in the plan is characterized by an uneven distribution of depths in its cross-sections. This is due to the curvilinearity of the turning section of the channel, which has an unacceptably small radius of curvature in the plan causing centrifugal forces and rising levels along the concave wall, which led to an overflow of water over the top of the channel walls. As a result of the conducted experimental - laboratory studies of the turning section of the outflow tract (channel), recommendations are given for reducing the water incursion on the banks, the height of the walls.
Calculation methods for plate and beam elements of box-type structure of building
Authors: Mirsaidov Mirziyod , Usarov Makhamatali , Mamatisaev Giyosiddin
Published: June 2021

The article is devoted to the dynamic calculation of the box-type structure of buildings for seismic resistance, taking into account the spatial work of the box elements under the influence of dynamic impact. The development of spatial calculations and the study of vibrations of elements of box-type structures, considering various factors, is an urgent problem of structural mechanics. In this article, a mathematical model and a numerical-analytical method were developed to solve the problem of dynamics using the finite difference method and expand the solution in terms of natural vibration modes in the spatial setting for the elements of box-type structures under the kinematic impact. The steady-state forced vibrations of box-type structures under stationary harmonic influences applied to the structure foundation are investigated, and the areas are identified where the greatest values of shearing forces and bending moments occur under harmonic influences.
Drafting land allocation projects for urban development based on GIS technologies
Authors: Babajanov Allabergan , Abdiramanov Rashid
Published: June 2021

The article scientifically describes the development of land allocation projects for urban purposes using geographic information systems (GIS) technology, one of the main forms of inter-farm land management, one of the state measures aimed at rational organization of land use. In addition, the scientific article should take into account the formation of the databases necessary for the development of such projects, the stages of data processing and analysis, as well as the issues that need to be addressed, as well as the development of feasibility studies for the implementation of such projects—key factors and key indicators, as well as expected project results.
New way to dampen the energy of medium- and high-pressure flows
Authors: Guryev Alim , Khanov Nartmir , Mareeva Olga , Fartukov Vasilii , Zhuravleva Anna , Verkhoglyadova Aleksandra
Published: June 2021

The current practice of hydraulic engineering construction applies four methods for damping extra energy of excess water discharge: throwing out the stream into the tailwater; using twisting of the stream in the water passageway, in a water-well, and on a multistage drop; and energy damping in a vertical shaft. The cheapest method is energy damping by throwing the jet into the downstream reservoir. The main disadvantages limiting the use of this method include the need for appropriate topographic conditions in the tailrace basin, strong rocks in the river channel, and the possibility of water throwing at a large distance from the hydropower project, which restricts the use of this method. Extra energy damping with the use of twisting flow in the water passageway requires complex structures, providing for a rotational movement of water and forming a deep vacuum in the outlet conduit. The breaking of vacuum requires a large amount of air, which causes dynamic modes, and its removal complicates the design of energy damping structures. The most reliable way of energy damping is damping in a stilling well. But the disadvantages of water-sucking wells are low efficiency accompanied by an uneven distribution of specific discharges in the inlet section and a sharp increase in the cost at high-pressure hydroelectric installations. The use of multistage cross-fall drastically facilitates the operation of a stilling well and serves as its supplement. Energy damping in a vertical shaft is easy to use. Still, it results in trapping a large amount of air at all operating modes, which has limited its practical use in hydraulic engineering construction. However, the damping of flow energy in a vertical shaft except for possible air supply has shown high efficiency of operation in combination with a diversion water pipe with a reverse slope. A variant of such design of flow energy damping in a vacuum vertical shaft has been developed and studied as applied to conditions of the Rogun hydropower project. Model studies of the design on the scale of 1:100 showed high efficiency and reliability in all possible ranges of discharged flow rates.
Influence of speed of filling and draw-off to the filtration regime of Earth-fill dam
Authors: Djabbarova Shahnoza , Muslimov Turovoy , Boymatov Shahriddin
Published: June 2021

To use and manage water resources and carry out protection measures from the destructive effect of water flow, water reservoir hydrosystem construction has greatly developed. The article presents the results of field studies to determine unsteady filtration in the Earth-fill dam core. In the research process, static data from literature review, field study data, and theoretical processing of research results were used. Numerical data processing was carried out with methods of mathematical statistics, and the graphical part was done using Microsoft Excel. Calculations were carried out for phreatic line curve in the core of Earth-fill dam under unsteady filtration for various velocities of reservoir draw-off and water yield coefficient. At the same time, it has been established that the increase of velocity and time of water reservoir draw-off leads to the increase of filtration pressure, and the decrease of water yield factor leads to the decrease of filtration pressure. The increase of filtration pressure, in turn, contributes to the increase of the intensity of unsteady filtration of the Earth-fill dam core.
Operating information-diagnostical system (IDS) BING-3 on the example of Andijan water reservoir
Authors: Rahmatov Norkobul , Choriev Jamshid , Ibraymov Oshiqmamut
Published: June 2021

The article provides recommendations on the possibility of implementing an automated system of diagnostical control over the operational condition of a dam. Implementation of BING-3 allows to control the opening of cracks in concrete structures, take readings from piezometers and air temperature sensors in an automatic regime. The article gives an analysis of instruments used for diagnostics and reasons for the failure of certain devices. It has been established that further use of morally out-of-date devices reduces dam safety observation volumes.
Assessment shoreline formation of reservoirs
Authors: Gapparov Furqat , Eshkuvatov Quvonchbek , Mansurov Safar , Gaffarova Mushtariybonu
Published: June 2021

The article analysis the factors influencing the reduction of reservoir useful volume, including the formation of shores, and proposes and method of their quantitative calculation. The research was provided in the South Surkhandarya reservoir. During the exploitation of the reservoir, were assessed the morphometric index of the basin and changes in a bank due to various influences. The article presented mathematical, statistical calculations of changes in erosion conditions due to displacement of the left banks of the South Surkhandarya Reservoir and changes in pressure in the strata and water saturation of the coastal layers. The proposed method of assessment and calculation will allow development measures to improve the operation of reservoirs based on the determination of morphometric parameters and prevent the formation of shores.
Hydraulic resistances experimental and field studies of supply canals and pumping stations structures
Authors: Uralov Bakhtiyor , Li Marina , Qalqonov Eshmatboy , Ishankulov Zokhidjon , Akhmadi Makhfuz , Maksudova Lyudmila
Published: June 2021

Currently, many authors have studied the uniform axisymmetric pressure head laminar and turbulent movement of water in hydraulic smooth and rough (with uniform roughness) pipes of circular cross-section. The results obtained in the study of a plane-parallel turbulent flow in pressure canals allows here only to outline the structure of the corresponding dependencies and to clarify the simplest case of unpressurized fluid movement, when this movement can also be reduced to plane-parallel or, in other words, to movement in a canal of infinitely large width with a flat bottom. In all other cases, the only way to solve the problem is an experiment. The construction of numerous free-flow watercourses and machine canals of pumping stations requires scientifically based calculation methods.
Conditions for bending cotton stalks of a combined aggregation bender and their implementation
Authors: Khudayarov Berdirasul , Kuziyev Ulugbek , Sarimsakov Bakhtiyar
Published: June 2021

As the object of the research, the cotton stalk and its physical and mechanical properties, the elastic of the combined aggregate and the spherical disk were accepted. Like many other European countries, our country has also developed minimal, resource-saving and zero technologies for the cultivation of agricultural products, and their technical solutions are being supported and implemented by farmers and clusters. In particular, in the preparation of cotton fields for sowing for the next year in one pass of machinery in cotton growing, the research was conducted on the development of a minimum technology and a combined unit that implements it. In the implementation of this technology, the cotton stalks are tilted to the side furrow in the direction of movement of the aggregate, and the root is laid on the bottom of the furrow with the soil. The bottom layer of the existing pile is then divided into two parts, each of which is rolled over the cotton stalks on the side edges on both sides, where a new pile is formed. Once the aggregate has passed, the existing ridges are replaced by ridges with cotton stalks buried under them, and ridges are formed in place of the existing ridges.

In the study, the angle of the axis of symmetry was determined by the angle of the stalks, and in the laboratory, the amount of force required to bend the stalks was determined using a specially prepared stand.

In the study, the width of the flexible cover is 45 cm, the mounting angle of the straight part of the flexible relative to the direction of movement is 35-450, the radius of curvature should be 100 mm, the mounting height relative to the ridge should be 15 cm, and the shape was determined.

Bending of cotton stalks standing on the ridge in the direction of aggregate movement to the side ridge, digging them with root soil, longitudinal laying at the bottom of this ridge can be done using a spherical disk.
Relative speed and temperature effect investigation of the of the drying agent on the moisture content of cotton
Authors: Rakhmonov Khayridin , Fayziev Sirojiddin , Rakhimov Khakimboy , Kazakova Dilfuza
Published: June 2021

In this article, the influence of the relative air velocity and temperature on the moisture transfer rate for raw cotton is studied. At relative air velocities varying from 0.05-0.6 m/s using a laboratory setup and different temperatures of the drying agent and humidity of raw cotton, the dependences characterizing the process of moisture sampling and desorption (drying) of raw cotton, as well as the diffusion process occurring inside the sample, are obtained.
Physico-chemical properties lime-ammonium nitrate based on chalk, nitrate and ammonium sulphate
Authors: Rasulov Oybek , Мamataliyev Abdurasul , Rasulova Dilnavoz , Temirov Uktam , Namazov Shafaat
Published: June 2021

For the granulation of nitrate-sulfate-carbonate melt, the prilling method is applied using a granulation tower. The composition and properties of new types of fertilizers were studied. It is shown that with the ratio NH4NO3: СаСО3: (NH4)2SO4 = 100: 24: 1 the product contains 28,03% - N, 0,50% - SO3, 10% - СаО and has a granule strength of 6.03 MPa, which is much higher than the strength of pure NH4NO3 granules (1.32 MPa). The absorption of pure AN granules is 4.82 g. With an increase in the proportion of chalk and ammonium sulfate to the NH4NO3: СаСО3: (NH4)2SO4 = 100: 24: 1 ratio, the absorbency of the LAN granules is 2.57g.
Technical justification of the application of double regulation of ground water level (sub-irrigation) in the conditions of the republic of Karakalpakstan
Authors: Turlibaev Zakir , Kurbanbaev Sagit
Published: June 2021

The article contains proposals for double regulation of the groundwater level to obtain a high yield with the lowest water consumption. In the article, all side-by-side studies of the issues of double regulation of the groundwater level and scientifically-based proposals are given on them. The report contains the results of studies carried out at experimental sites in the Khojaili region and Kungrad regions of the Republic of Karakalpakstan. According to the data of the conducted field studies on the collector, the calculated parameters were obtained for double regulation by the construction of retaining structures. During the growing season, the collector was locked, and the optimal soil moisture was achieved and, accordingly, the yield of agricultural crops was increased.
Investigation of various options for processing gray forest soil in a field crop rotation
Authors: Balabanov Victor , Lee Afanasiy , Norov Begmat , Khudaev Ibrohim , Egorov Victor
Published: June 2021

The paper presents the results of studies of various variants of the main treatment of gray forest soil in the experimental field in JSC “Lednevo” of the Yuriev-Polsky district of the Vladimir region Russian Federation. The experiment includes 12 strips, with an average area of 7.5 ha, consisting of 3 variants, with decreasing intensity of tillage and 4 repetitions. Based on the studies, it was found that the main problem associated with the physical condition of the soil was significant compaction of the soil at a depth of 20 – 25 cm. When using dump processing, increased soil heterogeneity was observed, and with “minimal” variants, the presence of weed vegetation was noted, which required changes in the strategy of using plant protection products and strict compliance with crop rotation. In this paper, it is recommended to remove the “plow sole” and reduce soil compaction by deep loosening of the soil to a depth of 35-40 cm in autumn, followed by a transition to a minimum soil treatment by cultivators.
Suggestions on increasing the germination seeds of pasture fodder plants
Authors: Mirzaev Bakhadir , Mamatov Farmon , Tulaganov Bakhtiyor , Sadirov Amir , Khudayqulov Rustam , Bozorboev Abbos
Published: June 2021

One of the problems in the seed production of pasture forage plants is low seed germination. Existing pasture improvement technologies and technical means for seed production, harvesting, post-harvest handling, and storage of pasture forage plants are analysed. Suggestions for improving seed germination have been developed: it is advisable to place the seed crops between the forest belts; to improve seed germination, it is necessary to make a preliminary harvest of seed crops with spreading the mass on the stubble; the mechanised collection of seed heaps using a rotary mower with an active heap separator increases the germination rate by reducing mechanical damage to the seeds and enriching the soil with organic matter; the seed sowing process has a positive effect on the germination rate of the seed produced, in addition to reducing cleaning costs.
Intensity of the continuous feed mixing process in the mixer
Authors: Eshdavlatov Eshpulat , Suyunov Alisher , Choriyev Islom
Published: June 2021

The physical basis of the mixture formation is analyzed. The study aims to increase the intensity of the process of continuous mixing of feed in the mixer. The basic principles and methods of classical mechanics, mathematical analysis, and statistics were used in this study. The design of the mixer cover in the form of a three-sided box is justified, which eliminates additional resistance to the rotation of the screw due to the impact of the feed masses reflected from the cover. When using a lid in the form of a three-sided box, the mixing quality improves by 4-5% and reaches 93% or more at a capacity of 15 t/h. It is established that the optimal angle of inclination of the reflecting plane of the mixing chamber cover is 31-35° with a screw diameter of 400 mm, the height of the reflecting plane from the screw axis of 350 mm, and a rotation speed of 36.61 s-1. The following indicators of the mixer were determined: the productivity that ensures the mixing quality of more than 90% when mixing green mass and silage with mixed feed - 19 t/h, crushed feed root crops with mixed feed-23 t / h, the speed of the screw - 36.61 s-1.
Plow for processing row spacing of gardens
Authors: Babajanov Laziz , Sharipov Zayniddin , Khakimov Bakhodir , Badalov Sunnat , Sobirov Eldor
Published: June 2021

Existing plows do not provide high-quality tillage between rows of orchards and vineyards. The purpose of the study is to develop and justify the parameters of the plow for cultivating the soil between rows of gardens to tractors of class 0.9 kN. A design scheme of a single-body plow for smooth, rowless plowing of garden aisles has been developed. The proposed plow consists of a movable and fixed frame, a disc knife, a screw body with a hostage. The research uses the laws of agricultural mechanics, mathematical statistics, and methods of strain measurement. The technology of cultivating the soil between rows of gardens with a single-body plow for smooth plowing is justified. To implement the proposed technology, the position of the plow body changes relative to the tractor during operation. It is established that when equipping a plow with a movable and fixed frame and performing a body width of 45-52. 5 cm, the required plowing quality is achieved with the lowest energy consumption.
Plant for cleaning oils from oxidation products
Authors: Kholikova Nargiza , Khakimov Bakhodir , Alikulov Saydilla , Ravshanova Nargiza , Mambetsheripova Ajargul
Published: June 2021

The study aims to substantiate the parameters and operating mode of the oil purification device from oxidation products to improve the efficiency of the use of lubricants. The methods of mathematical analysis and mathematical statistics, comparative comparison, generalization, and testing methods of agricultural machinery are used in the research process. It is established that engine oils are intensively polluted by oxidation products during processing, thereby accelerating the friction process due to the overload of tractor engines. During the performance of agricultural work in the oil composition, the content of oxidation products in the form of carbon, carbon dioxide, and asphalt products increases by 1.2%. Analytical coupling dependences for the process of cleaning motor oils from oxidizing products are obtained, and the dependence of the cleaning efficiency on the device parameters is established. The developed device consists of a container for collecting oils, a steam generator, a container for a sump mixer, a separate container for pure and sedimentary oils, and a vessel for re-collecting acetone. An installation has been developed to implement the technology of collecting and renewing oils in the conditions of the farm. In this case, the amount of contamination and the composition of oils is determined, and the operating mode of the device is selected for their resumption.
Mathematical model for calculating the reliability of the characteristics of the designed trailer frame
Authors: Togaev Anvar , Shermukhamedov Abdulaziz
Published: June 2021

The article looks through the justification of the projected frame reliability characteristics of the trailer and its components. Given the desired level of reliability for the frame as a whole promoted calculation of the required parameters of reliability, including the probability of failure-free operation and mean time between failure elements of the trailer frame. The substantiation of indicators of reliability and durability of the projected trailer frame is carried out. Based on the calculation of the complexity factors of the frame elements, the required reliability indicators were calculated, including the probability of non-failure operating (PNFO) and the mean time between failures (MTBF). To assess the frame's durability, the formula has been proposed with the correction coefficient εc, which can be used to calculate the resource of trailer frames made of elements of rolled steel of various grades. A mathematical model for evaluating the durability of the trailer frame is also proposed, based on the Weibull distribution and the power equation of the fatigue curve. A specific example shows the adequacy of the proposed formula to experimental values (The deviation from the experimental values of The Central Scientific Research Automobile and Automotive Engines Institute “NAMI” is 9 %).
The value of a complex unit for the simultaneous use of a transverse surface and a longitudinal ridge when irrigating cotton
Authors: Ostonov Shukhrat , Ikramova Makhbuba , Safarov Shavkat
Published: June 2021

The article provides data on the development of a complex Palodelatel unit without damaging growing plants, the simultaneous rate of a transverse surface and a longitudinal ridge in saline, sloping uneven soils in the Bukhara region, also taking into account the slope and unevenness of the soil relief, in a scientifically based form it is stated about the uniform provision of irrigation water and reduction of manual labor, working time, duration and distance between irrigation days, saving spent irrigation water and elimination of salt spots and reducing the cost of irrigation water by 25%, irrigation duration by 1.5-2 days, crop addition by 5-4.2 c / ha.
Processes of mixture formation, ignition and combustion of a diesel engine
Authors: Ismatov Jumaniyoz , Ergashev Obidjon
Published: June 2021

One of the most significant concepts of deep restructuring of the economic mechanism of the Republic of Uzbekistan is the creation of an integral, effective and flexible system of economic management and the implementation on this basis of a program to improve the technical level and quality of machines. The car park of our country is more replenished with vehicles with diesel engines. The development of contemporary diesel engine building is proceeding by forcing engines: increasing the average effective pressure and speed. Therefore, high reliability and service life, fuel efficiency and environmental performance are the basic criteria for their quality. Forcing diesel engines leads to an increase in thermal and mechanical loads on the basic parts of the cylinder-piston group (CPG) (piston, liner and cylinder head), a significant increase in their temperature, as well as the temperature of piston rings and valves. Overheating of parts is accompanied by the formation of temperature fields with a pronounced uneven temperature distribution and, as a result, an increase in thermal stresses with a simultaneous deterioration of the mechanical properties of the material, the formation of cracks and, finally, the destruction of the part. In this regard, the task of protecting parts from excessive exposure to high thermal loads from the working fluid becomes urgent, or, in other words, the task of creating a diesel engine with reduced heat removal from the working fluid.
Mathematical model for producing machine parts
Authors: Karimov Kamolkhon , Turakhodjaev Nodir , Akhmedov Azamat , Chorshanbiev Shukhrat
Published: June 2021

In the article, the object of research is the development of a technology for improving the operational properties of cast parts from steel 45, obtained by the method of electroslag remelting. Based on the research results, the modes of heat treatment of the shaft-gear part in an aqueous medium water-oil, heat treatment to increase the service life of the product, and energy-saving melting technology by the method of electroslag remelting were developed. Particular attention is paid to the development and analytical implementation of the mathematical model of the developed technologies by the methods of linear algebra by drawing up the Lagrange interpolation polynomial. Functional dependencies have been obtained for determining the amount of oxygen in the melt depending on the diameter of the electrode and the aluminum content in this electrode for any diameter of the mold, the hardness of the shaft surface depending on its diameter, the oxygen content (amount) in the melt depending on the aluminum content in the electrode for different mold diameters. Based on the developed and analytically implemented mathematical models of the investigated technological process, it seems possible to simplify experimental studies. In other words, based on analytical studies, it is possible to predict the results of subsequent experiments. Based on the developed and analytically implemented mathematical models of the investigated technological process, it seems possible to simplify experimental studies. In other words, based on analytical studies, it is possible to predict the results of subsequent experiments.
Selecting Control Parameters of Mechanical Systems with Servoconstraints
Authors: Khusanov Kahramanjon
Published: June 2021

The research results on the derivation of equations of motion (a mathematical model) of a mechanical system constrained by holonomic constraints of the first and second kind, which contains only tangential components of the constraint of the second kind, are presented in the article. These tangential components are taken as control parameters. Besides, the controllability of the plate, considered in the Appel problem, is investigated.
Theoretical substantiation of the influence of electric pulse processing on the process of obtaining juice from grapes and fruits
Authors: Eshpulatov Nodir , Khalmuradov Tolib , Khalilov Rakhmаnberdi , Obidov Abdulkhay , Nurmanov Sobir , Omonov Dilmurat
Published: June 2021

The article presents the theoretical basis of the effect of electrical pulse processing on the process of obtaining juice from grapes and fruits. High-voltage pulsed electrical processing technology for biological products has a higher damaging effect on living cells than other electrical effects, and this can be achieved due to the passage of large discharges of current through tissues and cells in a short period of time. It has been found that high efficiency in killing living cells by secretion can be achieved as a result of a pulsed energy effect. In order to develop energy-efficient electrical technology for extracting juice from fruits and grapes, it has been found that high-voltage electric pulse discharge treatment of grapes and apples before extracting juice has a good effect. Analytical expressions between electrical impulse processing parameters (pulse energy and capacitor capacity) and juice output were determined. The degree of damage to fruit and grape cells depends on the capacitance of the capacitor, the discharge voltage, and the number of pulses.
Longitudinal vibrations of a cylindrical bar from the action of harmonic forces
Authors: Abduvaliev Abdukakhkhar , Abdulkhayzoda Abdulaziz
Published: June 2021

The longitudinal vibration of a cylindrical rod has been studied in an elastic medium from the action of axial harmonic forces in a state of compression tension. The consideration took into account the damping of vibration of the rod according to the theory of E.S. Sorokin. Taking into account, internal friction made it possible to approach the real state of the rod as a source of wave radiation. The amplitude-frequency characteristic of the structure is built, taking into account changes in the parameters of the environment and the rod. The possibilities of the emergence of the resonance state of the rod are established. At the same time, cases were considered with and without inelastic properties of the rod material. The analysis of the influence of the properties of the environment and the rod on the amplitude of the displacement of the latter is carried out.
Developing a new monitoring mechanism of electronic document management of technical documentation for railway automation
Authors: Baratov Dilshod , Astanaliev Elmurod
Published: June 2021

The methods of creating automation tools in the general and analytical process and improving their efficiency are carried out in terms of brief comments on construction and creation and improving their efficiency. Electronic record keeping systems are considered. The creation of automated electronic document management systems and a comparative analysis of these processes are presented. Methods of analysis, synthesis and study of technical documentation electronic document flow are formalized. A graphical model of the electronic document management of technical documents is synthesized. The developed model considers the division of document flows into a set of participants, processes and situations. It is recommended to use a set of matrices to determine the form of presentation of the workflow of technical documentation. Based on the apparatus of graph theory, a method of creating an electronic document management model of technical documents are developed.
Variation of reaction forces on the axles of the road train depending on road longitudinal slope
Authors: Khakimov Shaukat , Fayzullaev Erkin , Rakhmonov Azimjon , Samatov Rustam
Published: June 2021

The article discusses the influence of the road longitudinal slope on variation in reaction forces on the wheels of the road train. The description of the longitudinal slope of the road and methods of its determination are given. The design diagram of the forces and moments acting on the road train during its movement uphill and downhill is presented. Equations for calculating the change in the load on the three axles of the road train, depending on the longitudinal slope of the road and the mode of movement, are presented. Based on the calculation results, graphs were constructed to illustrate the change in loads on three axles of the road train. The results show that the changes in the normal reactions on the front axle of the road train are significant, affecting the braking properties and driving safety of the vehicle. The scheme for calculating the variation in loads on the axles of a road train can be used to automatically adjust the braking forces between the wheels depending on the loads and thereby ensure traffic safety.
Improvement of control devices for road sections of railway automation and telemechanics
Authors: Saitov Aziz , Kurbanov Janibek , Toshboyev Zohid , Boltayev Sunnatillo
Published: June 2021

In this scientific article, control sensors and control devices have been improved based on the method of counting arrows of the rolling stock of railway transport. The microprocessor-controlled control unit and control system have been simplified to manage traffic between two stations, and a self-monitoring, reliable and risky scheme has been developed. Wiring diagrams of existing transport relays have been updated for uninterruptible power supplies, microprocessor devices, and sensors. An automated schematic diagram with a microprocessor for signaling a collision of a railway with wagons has been created, and the order in which the speed of train movement approaches the crossing has been maintained. The complex functional control of rolling stock was improved based on the method of counting bullets, electronic archiving of the movement of orders of the train attendant and dispatcher, as well as the operation of devices for monitoring the technical condition of the station.
Adhesion-strength and tribotechnical properties of machine-building composite polymer coatings
Authors: Negmatov Soyibjon , Ulmasov T , Karshiyev M , Makhammadjonov Z , Abdulayev O , Matsharipova M
Published: June 2021

The article presents the results of studies of adhesive, strength and tribotechnical properties of composite polycaproamide polymer materials and coatings based on them for mechanical engineering purposes. It has been established that the relative change in the adhesion strength depends on the degree of filling in air and in argon has an extreme character passing through a maximum for coatings based on PCA with aluminum oxide, and for coatings made of PCA with copper oxide, it has a complex character. The formation of adhesive, strength, and tribotechnical properties of filled polycaproamide coatings was also studied. At the same time, it was found that by adjusting the temperature-time technological modes, it is possible to increase the adhesive, strength, and tribotechnical characteristics of composite polycaproamide coatings for machine-building purposes.
Method for assessing the energy efficiency of a vehicle taking into account the load under operating conditions
Authors: Abdurazzokov Umidulla , Sattivaldiev Bakhramjan , Khikmatov Ravshan , Ziyaeva Shakhnoza
Published: June 2021

In operation conditions, the transport work of a vehicle is estimated by the increment in the mass of the freight over the distance traveled. This criterion does not characterize the mechanical work of the vehicle in the transport process. Without analyzing the energy costs of performing mechanical work, it is impossible to assess the energy efficiency of a vehicle.

The energy efficiency of a vehicle is defined as the ratio of the mechanical work performed by the vehicle to the potential energy of the source. In this paper, it is proposed to determine the engine torque by fuel consumption. The engine torque value depends on the energy required for driving the vehicle.

Based on the analysis of the results of computational and experimental studies, a method for assessing the energy efficiency of a vehicle with an internal combustion engine is proposed. The reliability of the results obtained is substantiated by the test results and the available information in practice.
Formation of the freight trains with a fixed train schedule
Authors: Svetashev Aleksandr , Kamaletdinov Shokhrukh , Svetasheva Nargiza , Mustaeva Guldora
Published: June 2021

The hypothesis of the study consists of the detailed consideration of the process of accumulation of wagons, taking into account the arrival of individual groups of wagons, determination of options for freight trains with a fixed train schedule and substantiation of analytical dependencies that determine the cost of wagon-hours for accumulating trains and obtaining new scientific results on this basis. Their practical use will make it possible to more accurately and reasonably normalize the idle time of cars under accumulation, as well as to clarify the methodology for calculating the train formation plan. The research methodology is based on existing methods and methods of forming freight trains for a rational way of implementing the train schedule. Results of the study: the methods of standardizing the idle time of cars under accumulation were stated, the regulations of idleness of cars at the sorting yard were clarified, and options for optimizing the plan for the formation of trains were proposed.
Determination of installation bases of parts during their mechanical processing
Authors: Ubaydullaev Gayrat , Riskaliev Davron , Ergashev Nurilloxon , Rashidov Aziz , Shadiev Sanat
Published: June 2021

The article discusses the issues of determining the installation bases of parts during their machining. To solve this problem, its graph model was used in the place of the part itself, reflecting its structural dimensions of the connection. In this case, the determination of the installation bases was achieved by dismembering the original graph of the detail, not subgraphs, followed by their evaluation by the corresponding optimization criteria.