bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental study of hydraulic equipment operation process
Authors: Rustamov Kamoliddin , Komilov Samandar , Kudaybergenov Mavlon , Shermatov Shamshir , Xudoyqulov Shahzod
Published: June 2021

Relevance. When the hydraulic fluid is operated for several cycles, the impact on hydraulic performance and longevity is greatly increased. So, there are several ways to fix this problem. To increase the efficiency of the hydraulic system, it is necessary to study the working processes, the hydraulic systems of the quick-change equipment of the machine with a lawn of the kshpare made as a whole, and the equipment of the machine is attached to the suspension device. The complexity of these processes lies in the fact that they allow experimental research and verification of results using mathematical models.

Aim. The purpose of the experimental study in this dissertation is to study the effect of forces acting on the hydraulic system when excavating the hydraulic system of a multipurpose machine and substantiate the parameters by assessing power use efficiency.

Methods. Checking the suitability of the working fluid during earthworks, as well as the mathematical model. In this case, we studied the hydraulic system of a single-bucket excavator, the device of quick-change equipment for a universal machine.

Results. The theoretical work performed has been verified and the confirmation of the operation of a multipurpose machine designed with earth and dozer equipment. The installation of equipment based on TTZ-80 made it possible to carry out experimental research with the most energy-intensive workflow, determining energy efficiency indicators for excavation and leveling.

Conclusion. Comprehensive tests made it possible to conclude that the characteristics of the developed design and the characteristics of the engine of the base machine - the TTZ-80.10 - KM-1 tractor, overcome the resistance encountered during technological operations of a multipurpose machine.
Mechanical Properties and Design of Concrete with Hybrid Steel and Basalt Fiber
Authors: Dvorkin Leonid , Bordiuzhenko Oleh , Zhitkovsky Vadim , Gomon Svyatoslav , Homon Sviatoslav
Published: June 2021

Adding different fiber types may yield improvement of steel fiber reinforced concrete (SFRC) features. Therefore, the investigation of hybrid fiber reinforced concrete (HFRC) mechanical properties is relevant. The effect of adding hybrid steel and basalt fiber on the mechanical properties of fine-grained concrete is studied. It is shown that hybrid fiber reinforcement using optimal steel and basalt fiber ratio allows preventing concrete mixtures' segregation and improving their structure homogeneity. This, in turn, allows achieving higher concrete strength values. In most cases, the design of such concrete compositions is based on engineering experience that limits the designers' capabilities. Therefore, an effective methodology for proper HFRC composition design should be developed. The present study is focused on developing such a methodology. The developed methodology includes using the mathematical experiments planning method to design optimal composition of high-strength fine-grained fiber reinforced concrete with hybrid steel and basalt fiber reinforcement. It is demonstrated that the proposed method can be effectively used for the design of optimal compositions of HFRC.
Underground polymeric l-shaped pipeline vibrations under seismic effect
Authors: Nishonov Nematilla , Bekmirzaev Diyorbek , Ergashov Akbar , Rakhimjonov Ziyoviddin , Khurramov Asror
Published: June 2021

The simultaneous equations of longitudinal and transverse vibrations of an underground polymeric L-shaped pipeline under the arbitrary direction of seismic load were derived in the paper. A computational scheme of the problem was constructed using central finite-difference relations. The analysis of the results obtained on the simultaneous longitudinal and transverse vibrations of underground polymeric L-shaped pipelines under seismic loading was conducted. The stress-strain state of the L-shaped polymeric pipeline subjected to seismic effect was determined, and the axial forces and bending moments arising in curved pipelines during an earthquake were determined.
High-strength concrete technology for manufacturing reinforced concrete sleepers from prestressed reinforced concrete
Authors: Turgunbaev Urinbek , Umirova Movluda
Published: June 2021

The properties of concrete with complex chemical additives to improve the technology for the production of sleepers from prestressed concrete are discussed in the article. With the use of complex chemical additives under heat-moisture processing, at a temperature of 40°C, there was no decrease in the strength of the cement stone and sufficient strength at the initial stage of the curing period, 44.7 MPa; concrete strength was determined with the addition of Glenium 27 S - 1.0% and the hardening accelerator Master X -Seed 100 - 1.2%. Thus, the use of complex chemical additives makes it possible to solve the problem of achieving the necessary early high strength of concrete to implement low-temperature technology in the production of reinforced concrete sleepers.
Propagation of a spherical wave in elastoplastic medium with complex equations of state
Authors: Khudainazarov Sherzod , Donayev Burkhon , Ashirov B
Published: June 2021

The propagation of a spherical wave in the soil is solved in an analytically inverse way for soils with more complex equations of state. The results are obtained to propagate a spherical shock wave in soil with a more complex equation of state for the shape change in the medium. The study shows that taking into account the nonlinear elastic shock waves of the annular stress leads to an increase compared to the elastic medium. Note that in using a complicated equation of state of the soil, a spherical shock wave propagates in the soil, behind the front of which, in the disturbance region, the medium is unloaded.
Tracking the local seismicity level in the active influence zone of the southern Uzbekistan reservoirs
Authors: Khamidov Lutfulla , Turapov Mahmud , Mahkamov Soqijon , Artikov Farkhod , Suyunov Shavkat
Published: June 2021

Assessment of local seismicity caused by human engineering activity is a necessity after several earthquakes have been recorded in world practice, which destroyed a hydraulic structure, a dam and accompanied by human casualties.

The Tupalang, Gissarak and Pachkamar reservoirs, operated in southern Uzbekistan, are located in the mountain system of the southern part of the Tien Shan seismogenic fault.

According to the general seismic zoning, the zones where these reservoirs are located are classified as 8-9 magnitude shakes during strong earthquakes. Localisation of local earthquakes associated with the operation of these reservoirs is necessary for taking operational measures to prevent possible emergencies associated with an increase in the level of technogenic seismicity.

Methods for assessing the local seismic regime were used to track the level of local seismicity. The catalogs of local earthquakes occurring in the zone of active influence of reservoirs have been compiled.

The seismic activity levels and changes in the angle of inclination of the recurrence of earthquakes were determined for each object separately. The dependence of the variation in the level of local seismicity on the mode of operation of reservoirs has been revealed.

Several evidence of the negative impact of large hydraulic reservoirs on the deformation and seismic state of the zones of influence of reservoirs in southern Uzbekistan have been identified.
Dynamic characteristics of pilot boards of structures
Authors: Alimov Khorisboy , Buzrukov Zakiryo , Turgunpulatov Mirzohid
Published: June 2021

This work is devoted to studying the issues of vibrations of pile foundations, taking into account soil conditions for various types of fastening of piles to structures and the development of rational methods for choosing the parameters of piles and their number in earthquake-resistant construction. Based on the results of theoretical studies, resonance curves were constructed for three types of fastening of the "structure-group of piles" system. A special technique was proposed, and a series of field tests were carried out to determine the amplitude-frequency characteristics of the system.
Determination of deformations and self-stress in concrete on stress cement
Authors: Salikhanov Saidkhan , Pulatova Zulfiya , Zakirov Fahriddin , Rahimjonov Ziyavuddin , Abdullayev Abdurahim
Published: June 2021

The article considers using a single-layer reinforced ten-centimeter layer of concrete on stress cement instead of the traditional multilayer construction of waterproofing bridges. The proposed design will ensure the water tightness of the bridge deck due to the self-stress in the concrete on the stressing cement, the value of which is proportional to the deformations of concrete and reinforcement. Concrete deformations are uneven over the layer height, and the resulting stress in concrete depends on the reinforcement coefficient. Experiments were carried out to determine the deformations of concrete and the magnitude of self-stress, which provides the waterproofing properties of a bridge deck made of concrete on stress cement. The study of the self-tension process, identifying those factors on which its value depends, is necessary for a correct understanding of the physics of the self-tension process. In addition, it is necessary to check the applicability of various proposed empirical dependences for concrete on stress cement of the composition under consideration.
Development of two-stage alkaline refining of oils obtained from low-grade cotton seeds using caustic soda, sodium silicate and microwave radiation
Authors: Akhmedov Azimjon , Rakhmatov Eldor , Rajabova Dilfuza
Published: June 2021

The article substantiates the improved technology of two-stage alkaline refining of oils obtained from low-grade cotton seeds using caustic soda and sodium silicate. On the basis of the technological scheme, the norms of technological modes have been developed. In the pilot production conditions of Karshiyog-extraction JSC, we tested the developed technology of two-stage alkaline refining of oils obtained from low-grade cotton seeds and ultrahigh-frequency radiation. The developed technology makes it possible to significantly reduce the color, acid, and peroxide numbers and the mass fraction of unsaponifiable substances in the resulting oil. This helps to increase the yield of bleached oil, reduce the consumption of bleaching clay and improve the quality and food safety of the resulting product. As a result, the yield of refined cottonseed oil, obtained from low-grade cotton seeds, increased by 1.1 times (90%) (compared to the traditional one (85.1)).
Exact method to solve of linear heat transfer problems
Authors: Abdullayev Akmaljon , Kholturayev Kholsaid , Safarbayeva Nigora
Published: June 2021

When approximating multidimensional partial differential equations, the values of the grid functions from neighboring layers are taken from the previous time layer or approximation. As a result, along with the approximation discrepancy, an additional discrepancy of the numerical solution is formed. To reduce this discrepancy when solving a stationary elliptic equation, parabolization is carried out, and the resulting equation is solved by the method of successive approximations.

This discrepancy is eliminated in the approximate analytical method proposed below for solving two-dimensional equations of parabolic and elliptic types, and an exact solution of the system of finite difference equations for a fixed time is obtained.

To solve problems with a boundary condition of the first kind on the first coordinate and arbitrary combinations of the first, second and third kinds of boundary conditions on the second coordinate, it is proposed to use the method of straight lines on the first coordinate and ordinary sweep method on the second coordinate. Approximating the equations on the first coordinate, a matrix equation is built relative to the grid functions. Using eigenvalues and vectors of the three-diagonal transition matrix, linear combinations of grid functions are compiled, where the coefficients are the elements of the eigenvectors of the three-diagonal transition matrix.

Boundary conditions, and for a parabolic equation, initial conditions are formed for a given combination of grid functions. The resulting one-dimensional differential-difference equations are solved by the ordinary sweep method. From the resulting solution, proceed to the initial grid functions.

The method provides a second order of approximation accuracy on coordinates. And the approximation accuracy in time when solving the parabolic equation can be increased to the second order using the central difference in time.

The method is used to solve heat transfer problems when the boundary conditions are expressed by smooth and discontinuous functions of a stationary and non-stationary nature, and the right-hand side of the equation represents a moving source or outflow of heat.
The effect of a complex additive on the structure formation of cement stone in conditions of dry hot climate and saline soils
Authors: Narov Rustam , Akhmadiyorov Ulugbek
Published: June 2021

In DHC and saline soils and groundwater conditions, the cement mix quickly loses its mobility and workability. In this regard, it is necessary to plasticize it by introducing various surfactants. However, the surfactant additive used should not slow down the process of hydration and hardening. To ensure salt resistance, it is necessary to increase the density and the strength of concrete. The proposed complex additive was obtained by joint grinding in a ball mill of a soda-sulfate alloy (SSA) and gossypol resin (GR) to a specific surface area of 2800 cm2/g at the rate of 05, -1.5%, and 0.1-0.3%, respectively, of the cement mass. The complex additive was introduced into the mixing water of the cement mix. From the research results obtained, it is seen that with an increase in the content of GR from 0.1 to 0.3%, the normal density decreases by 1.4-4 points, and the setting time (due to the accelerating action of the SSA) decreases at the beginning by 20-50 minutes, and at the end by 60-240 minutes. In 28 days, the control cement gained the strength of 56 MPa, and with a complex addition - 60-68 MPa. The introduction of a complex additive led to an increase in the salt resistance coefficient in the reference cement up to 0.55-0.65, and in the cement with a complex additive up to 0.80-0.86; an increase was observed due to the strength and density of the samples. By increasing the strength, it is possible to save 17-21% of cement.
Construction technology and quality control of expansion joints with rubber compensators
Authors: Mukhametrakhimov Rustem , Aliullova Indira
Published: June 2021

Expansion joints play an important role in the operation of bridge construction. The reliability and durability of most of the other structural elements of the bridge depend on its quality and have a significant impact on road safety. One of the most effective types of expansion joints is rubber compensators, the service life of which directly depends on the quality of its installation. In this work, the types and classifications of expansion joints of bridge construction are studied, their defects and causes of their appearance are analyzed, a visual inspection of the state of expansion joints of the bridge is performed. The technology and quality control system of technological processes for constructing s single-profile expansion joints with rubber compensators during the repair of bridge construction is proposed.
Influence of cavitation on pressure pulsation through impeller of large pumps
Authors: Ergashev Rustam , Azimov Azam , Kholbutaev Вoybek , Mavlonov L
Published: June 2021

The article provides the main recommendations for studying the processes of cavitation development on the models of pumping units OPV-10-260 and V 20-13/45 with an impeller diameter Dr = 250 mm. The nature of the effect of cavitation depends on forms of pressure pulsation. The purpose of this work is to study abrasive-cavitation erosion of large pumps. The research objectives are to develop a methodology for calculating their operating modes, taking into account the minimum deterioration of working parts. Strongly developed cavitation leads to disruption of regular pulsations and an increase in the swing of the high-frequency component. Investigations of operating mode of pumps with deterioration of elements of flow section were carried out, and the characteristics of materials for the manufacture of hydromechanical equipment for resistance to cavitation deterioration were refined. According to experiments, the influence of pressure on the pressure fluctuation range begins to significantly affect if the pump pressure is less than 5 m. The nature of the effect of cavitation depends on the forms of pressure pulsation. The complexity of composition, high cost of high-alloy steels, and non-ferrous alloys make it irrational to use them in massive parts operating under cavitation-abrasive conditions. It is recommended to use the developed dependencies on machine water elevating systems to reduce deterioration by improving the quality of impeller materials.
Erosion processes during non-stationary cavitation of irrigation pumps
Authors: Dzhurabekov A , Rustamov Sh , Nasyrova N , Rashidov J
Published: June 2021

The article gives the main results of the study of the dynamics of wear of the working bodies of irrigation pumps, gives the main recommendations as a result of the study of pumping units in the presence of cavitation. The authors consider the cavitation coefficient as the minimum value of this expression, at which the beginning of cavitation is detected. The process of unsteady cavitation is accompanied by many significant effects in which the water flow becomes two-phase, with a corresponding change in its properties, which affects the pump's efficiency. The effect of particle size on the erosion rate is predominant only up to a certain size limit, i.e., 600-800 microns on the blades. After that, the erosion rate increases with a comparatively slower rate. This indicates that the particle size affects the erosion rate only up to a certain particle size.
The method of hydraulic flushing calculation of the reservoir of the "Indian type" hydrosystem
Authors: Kan Eduard , Nasrulin Aydar , Teplova Galina
Published: June 2021

One of the main problems in the operation of hydrosystems for various purposes is the silting up of the reservoir. Silting up of a reservoir leads to a decrease in useful capacity. And, of course, the hydrosystem's facility will not be able to fully perform its functions. This issue is particularly relevant for territories located in the arid zone with transboundary rivers, whose water resources are used for industries with different types of water consumption (first of all, irrigation and energy). The most common type of cleaning of silted reservoirs currently used is hydraulic flushing. The advantages of this method are the simplicity of the technological process; the disadvantage is the large consumption of water for washing, which is especially important in conditions of constant shortage of water resources. A method for washing reservoirs of Indian-type hydrounits is proposed. The technique considers the characteristic design features of a particular hydroelectric complex, operating experience, and field research data (sediment characteristics). The proposed technique was applied at the Ravatkhodzha hydro complex.
Results and analysis of field research in flood reservoirs in Kashkadarya region
Authors: Yangiev Аsror , Adjimuradov Dilmurat , Panjiev Sherzod , Karshiev Rustam
Published: June 2021

The article presents field research conducted in Langar, Dehkanabad, Shurabsoy flood reservoirs in the Kashkadarya region. Many problems result from floods in the reservoirs; there are disturbances in the discharge and drainage facilities during the passage of accidental floods. At the same time, there was a large accumulation of turbid sediments in flood reservoirs. In the article, the calculations using empirical formulas for predicting the number of turbid sediments in Langar, Dehkanabad, Shurabsoy flood reservoirs up to 2025-2030 years are also presented, and it is noted that at present, their useless volumes are full of turbid sediments. Preliminary recommendations for assessing the safety of flood reservoirs have been developed.
Parameters of the comb-forming machine with elastic rods
Authors: Kiyamov Asror , Norchayev Davron , Razzakov Tura
Published: June 2021

The study aims to substantiate the design and parameters of the comb-forming device with elastic rods. The basic principles and methods of classical mechanics, mathematical analysis and statistics were used in this study. The authors proposed a comb-forming machine with elastic rods for sowing cotton on the combs. The main parameters of the comb-forming machine with elastic rods and the amount of vertical load on the working body are justified by experimental studies. It is established that with a diameter of 3 mm elastic rod, the number of elastic rods 64 pieces, a radius of 0.3 m disks and a width of 0.60 m device capture provides high-quality destruction of soil lumps and the formation of ridges of the required shape.
Hydraulic automatic regulator of level with flexible working bodies
Authors: Kadirova Mukaddas-Gaukhar
Published: June 2021

To eliminate the shortcomings of the known hydraulic autoregulators of the water level, together with Ya. V. Bochkarev, we developed a design of a hydraulic autoregulator of the level with flexible working bodies, combined with an automatic gate for washing sediments, which provides the discharge of floating bodies and bottom sediments in front of the partition structure. To ensure stable vibration-free operation of this hydro-automatic level controller, the task was set to justify the shape and size of the elements of its main gate and the gate-automatic washing of deposits and determine the throughput of the automatic gate washing of deposits. As a result of solving this problem, for the stable vibration-free operation of the hydro-automatic level controller, a non-vacuum shape of the profile of the spillway part of its main gate was adopted, the shapes and sizes of other gate elements were justified, and a theoretical formula for the throughput of the automatic gate for washing sediments was obtained, taking into account the lateral outflows.
Assessment of damage during the formation and passage of mudflows in the Tashkent region
Authors: Shaazizov Farrukh
Published: June 2021

Mountainous and largely foothill areas of the Republic of Uzbekistan are mudflow hazardous. In the Tashkent region, there are two mudflow river basins (dangerous concerning the manifestation of mudflows): the Chirchik river basin and the Akhangaran river basin. Based on the results of long-term observations of the Uzhydromet service, a digital map of the mudflow hazard in the Tashkent region for a century was compiled. The method for determining the damage from the action of mudflows on a specific object consists of determining the equivalent mudflow pressure according to its initial parameters. According to the methodology for assessing damage in the event of a natural emergency, the main parameters of the damaging factors were determined during the passage of a mudflow in the event of intense rainfall. The calculations were performed for two scenarios: 1) with dangerous rainfall with an intensity of 30 mm per day; 2) in case of especially dangerous rainfall with an intensity of 60 mm per day. Based on the calculations performed, the amount of damage to the national economy of the Tashkent region was determined during the passage of a mudflow caused by intense rainfall.
The technique development of non-washing of mineral fertilizers in the soil through the screen formed on the interpolymer complex basis
Authors: Gadaev Nodir , Gulomov Daulet , Egamov Jumanazar , Nasirova Malika , Norboyev Jaloliddin
Published: June 2021

The problem of global climate change is on the agenda of mankind, not only because of the average annual temperature rise on the planet but also because of changes in the entire geosystem, rising global oceans, melting ice and permanent glaciers, increasing uneven rainfall, changing river flow patterns and climate instability, other changes involved. The world pays special attention to research work to develop technologies for the management and efficient use of water resources. In particular, it is important to conduct research to develop new water-saving irrigation technologies using cheap and chemical, and technical means.
Methods for calculating the balance during the period of draw-off, drainage of sludge collector cells and construction of secondary embankment dams
Authors: Fayziev Khamidkhon , Sultanov Takhirjon , Toshmatov Elyor
Published: June 2021

An industrial waste-phosphogypsum-is formed in the production of phosphorus mineral fertilizers. As is well-known, the issues of processing and utilization of phosphogypsum on an industrial scale remain unsolved. Consequently, production waste generated at chemical plants is stored in various types of storage tanks. The currently used hydraulic storage method provides for the supply of waste in the form of a slurry into the hydraulic dump cells, their sequential dehydration in the dump, and the subsequent development of a part of the stored waste for the construction of secondary dams. However, due to the low water-release properties of phosphogypsum, it is impossible to ensure its dehydration to the required degree, in large volumes, and the required period. Therefore, various designs of watertight diaphragms and drainage devices are provided in the sludge collector to accelerate the process of dehydration of the phosphogypsum strata. The balance of the sludge collector should be assessed in two periods: the initial period when the sludge collector cells are filled, bounded by the primary dam, and the subsequent period when the reservoir is built up by erecting secondary dams from the stored material. In the initial period, the operating mode of the sludge collector is divided into two stages: in the first stage, a pond is formed above the layer of sludge with a certain predetermined depth; in the second stage, this depth of water in the pond is kept constant by the spillways. The second build-up period is preceded by a period of cell preparation, namely: the draw-off of the pond and drainage of the cell to a moisture content suitable for the dam filling and normal operation of the mechanisms used in the construction of dams. This article presents the results of filtration studies in sludge collectors with an impermeable screen (made of polymer film, asphalt-polymer concrete, etc.) above the screen drainage system. The calculating methods for the determination of filtration parameters in the second period of operation are described: when the pulp supply stops, and a pond of clarified water with a depth of H0 is drawn off.
Assessment of water quality in the downstream of the Amu Darya basin
Authors: Karimboev Feruzbek , Gulomov Daulet , Tillayeva Zarina
Published: June 2021

Ecosystem vulnerability increases significantly when anthropogenic factors overlap with the effects of adverse climate change, which together negatively affect biodiversity and ecosystem functioning. According to ADB forecasts, the inflow to the lower reaches of the Amu Darya will decrease by 26-35% by 2050. The combined effect of higher water demand and lower inflow will increase the current water shortage - the annual water shortage will increase to 50% of the total demand. In connection with the projected changes, the current state of water resources of the Amu Darya river, as well as the need for the socioeconomic development of the region, the task of assessing the projected impact of climate change on the availability and quality of water resources becomes urgent.
Experimental study of horizontal effects of flow on non-erosion absorbers in the presence of cavitation
Authors: Obidov Bakhtiyor , Vokhidov Oybek , Suyunov Javlon , Nishanbaev Khayrulla , Rayimova Iroda , Abdukhalilov Abomuslim
Published: June 2021

This article is devoted to one relatively small issue of the dynamics of hydraulic structures, the determination of horizontal hydrodynamic loads on energy absorbers of a high-pressure catchment area in a cavitating flow in the presence of erosion-free absorbers. In connection with the intensive construction of high and medium-pressure hydroelectric systems, spillways that operate at high flow rates, a very urgent task is to develop reliable and economical downstream devices that provide intensive damping of flow energy in a stilling well with favorable uninterrupted flow regimes and the absence of cavitation erosion of streamlined elements.

Traditional methods of extinguishing energy using stilling wells and walls do not always solve the problem. In several cases, additional elements such as energy absorbers are installed, which effectively deal with malfunctioning currents. However, most of the used types of absorbers have a serious drawback - they are destroyed during cavitation studies by prof. N.P. Rozanov and his students made it possible, based on experiments, to develop several types of erosion-free or close to erosion-free dampers and obtain a dependence to determine the hydrodynamic loads acting on them at various stages of cavitation. This made it possible to use energy absorbers at high flow rates, which was done at the spillways of the Shamkhor and Artyomovsk hydroelectric power plants.
Hydraulic regimes and hydrostatic pressure of the flow on the elements of fastenings of the downstream of water outlets
Authors: Khidirov Sanatjon , Ishankulov Zokhidjon , Kosimov Jakhongir , Tadjieva Durdona , Nurmatov Panji , Ashirov Boyburi
Published: June 2021

A comprehensive study of the flow of water plays an important role in the design of the area of the lower reaches of the drainage and drainage structures of hydraulic structures. In particular, the complex processes associated with the flow movement in the lower reaches of low and medium pressure reservoirs play an important role in the selection of the appearance of the structure, structural elements and their shapes, sizes and location conditions. One of the important issues is to assess the strength of the elements of the lower basins of water intake facilities and hydropower plants in the current reservoirs, to determine the mode of connection of the basins, to improve the methods of quenching kinetic energy in the reinforced areas of the lower basin. Based on the 2 schemes adopted in this article, the hydrostatic pressures of several types of power extinguishers installed in the area of the water injection well, providing the bottom pound strength, were determined for the experimental device.
Hydromorphological characteristics of the rivers of Algeria
Authors: Maalem Nureddin , Begmatov Ilkhom
Published: June 2021

The article presents the results of a study on the water regime of the rivers of Algeria, which are characterized by a flood feeding regime. The flood regime is mainly formed from heavy rains, the flow of which is 80-90 % of the annual flow. Due to the short duration of rain floods, stationary hydrological posts do not always register them, so they can be characterized as single-modal, which simplifies their design possibilities. For the design of hydrographs of rain floods, a parabolic model-a flood scheme is adopted, and the main characteristics of hydrographs are determined according to this scheme.
Subsidence deformations of the foundations of hydraulic structures
Authors: Хujakulov Rustam , Zaripov M , Normurodov U
Published: June 2021

One of the most important tasks in designing and constructing reclamation network structures on loess subsidence soils is to ensure their long-term trouble-free operation. The improvement of methods for the design of hydraulic structures on subsidence foundations requires further study of very complex physical processes occurring in the foundations of structures during their construction and operation. This is confirmed by the fact that even if all the requirements and recommendations of regulatory documents for the design of irrigation systems on subsiding soils are observed, the deformations of the foundations of structures often significantly exceed the calculated ones, which can cause a loss of serviceability of irrigation structures. This determines the need for further study peculiarities of interaction of irrigation structures with their subsidence bases. This article is devoted to this problem, in particular, to the study of the influence of stress redistribution in wetted subsidence foundations of hydraulic structures on the stressed state of their elements and the stress-strain state of loess subsidence foundations on the models of float bets of hydraulic structures in the Karshi steppe.
Calculation of bottom sediment discharge in trapezoidal channels
Authors: Latipov Shakhboz , Gayimnazarov Isroil , Eshev Sobir , Babajanova Iroda , Babajanov Yuldash , Shodiev Bobur
Published: June 2021

The article shows the advantages of the Van-Rijn method from the analysis of existing calculation methods for determining the sediment discharge. Based on the results of laboratory studies and the Van-Rijn dependence, dependence was obtained to determine the discharge of bottom sediment, taking into account the establishment of the channel slopes. The resulting dependence is compared with the dependences obtained by other researchers, and these comparisons show good convergence between them.
Irrigation pumping stations according to the hydraulic and operational indicators of pumping units
Authors: Mamajanov Makhmudjon , Uralov Bakhtiyor , Li Marina , Qalqonov Eshmatboy , Nurmatov Panji , Gayur Abdulatif
Published: June 2021

The paper presents the conditions and the degree of reduction of water supply and pressure of pumping stations (PS) depending on the hydraulic resistance of the water-supply channels and structures of the PS and other various factors. And also, the results of studies of the hydraulic and operational modes of water-supplying machine channels and structures of irrigation pumping stations are presented. Analyzing the operating conditions of the pumping units, it was found that the reasons for the decrease in their operating parameters are the following: a) an increase in the hydraulic resistance of the suction line due to sediment deposition in the intake chamber, as well as due to siltation and clogging of the PS suction pipeline; b) an increase in hydraulic resistance due to the accumulation of air at elevated points of the pressure pipeline, in particular, on the crest of the siphon outlet of the PS; c) a decrease in the hydraulic efficiency of pumping units due to an increase in the surface roughness of the parts of the flow path, it due to the effect of solid abrasive particles entering through the suction line of the PS. Also, the work presents the results of complex laboratory and field studies to study the intensity of wear of the elements of the flow path of centrifugal and axial pumps. The alternating pulsating load leads to an increase in the force of interaction of the hydroabrasive flow with the surface of the chamber and increases its wear by 10%, and also reduces the productivity of the pumping unit to 9%.
Force effects of the flow on energy absorbers in the presence of cavitation
Authors: Umurzakov Uktam , Obidov Bakhtiyor , Vokhidov Oybek , Musulmanov Furqat , Ashirov Boyburi , Suyunov Javlon
Published: June 2021

As the experience of operating high-pressure spillway structures shows, the operating conditions of the downstream extinguishing devices are very difficult.

At flow rates, more than 12–15 m/s, downstream damping devices, as a rule, operate in a cavitation mode. First of all, this mode of operation gives rise to erosional destruction of the damper itself and the waters near it. This occurs where the cavitation torch closes on the structure.

Attempts to avoid these desirable phenomena by lining erosion sites with steel sheets do not always lead to the desired result since it is not uncommon for the steel lining to be torn off by hydrodynamic forces.

The separation of the cladding occurs in two cases: firstly, when the cladding is not in close contact with the concrete to be protected, and secondly, its anchoring is not enough. In both cases, fracture occurs from fatigue phenomena in the metal due to multiple oscillatory cycles from hydrodynamic loads.

It is difficult to avoid this in cavitation modes since the spectrum of pressure pulsations, in this case, is very wide, which leads to oscillations of linings at resonant frequencies. Apparently, the strength of the linings is an object of special research, and in the future, it should be dealt with theoretically and experimentally.

Hydrodynamic forces at high flow rates in the zone of intense energy extinguishing can reach such values that they can lift and overturn concrete slabs of water walls and water walls.

Currently, there are practically no specific and accounting for vertical hydrodynamic loads on slabs of water walls in the presence of cavitation on erosion-free absorbers in the technical literature.

To a certain degree of approximation, it is possible to use experimental data obtained on a model of the same structure but operating without cavitation, as data on hydrodynamic loads in the downstream of structures operating in a cavitation mode. The main disadvantage of such comparisons is that there is no guarantee that the amplitude and frequency characteristics of the flow during cavitation do not change (in particular, the amplitudes do not increase) as the cavitation limit is approached.
Geodatabase interpolation method development using GIS technology for changes regional assessment monitoring in hydrodynamic parameters of groundwater status in Syrdarya region
Authors: Ruziev Ilkhom , Nurjanov Satbay
Published: June 2021

In the Republic, especially in the Syrdarya region, the reclamation state of irrigated lands and soil salinization is inextricably linked with the level of groundwater, their salinity, and movement. The level of groundwater and its salinity depends largely on the technical condition of the drainage networks and the amount of atmospheric precipitation, the supply of fresh water during the vegetation period, and groundwater movement from outside. The future of using GIS in a different sphere is discussed. GIS gives possibilities to collect the data, renewing it, or use new information in the analysis. It requires a quick change of GIS information about Earth because procedures in the Earth are dynamically changeable. Periodically changing information in GIS gives us the possibility to get new information and analyze it. GIS technologies and techniques started using widely in all spheres of humanity. It is important to know its properties. The main and effective method of land reclamation is the construction of collector-drainage systems and the maintenance of groundwater level, preventing secondary salinization of land by irrigation and drainage water. GIS is currently widely used and implemented in agriculture and water management and land reclamation monitoring in Uzbekistan and all over the world. Data analysis and transmission and storage within the GIS are addressed in GIS.
Influence of electric power and other forces on the quality of cotton seeds on the surface of working body
Authors: Shoyimov Pаrda , Murodov Bekhruz , Xafizov Khudoyor , Murodova Barchinoy
Published: June 2021

The article covers the “Dielectric” device for sorting seeds of agricultural crops and results of theoretical research on seed sorting on this device. The results of theoretical experiments showed that the expected result could be achieved by applying a high voltage to the electrodes of opposite sign, the diameter of the working body of the device, and the number of turns to seed sorting in the “Dielectric” device.
Methods for calculating the pressure loss of the air flow and energy consumed by the fan of the cotton harvester
Authors: Matchanov Rafik , Rizaev Anvar , Yuldashev A , Kuldoshev Davronbek , Mirzaeva M
Published: June 2021

The article presents the methods for calculating the pressure loss of the pneumatic transport system of a cotton harvester related to the power consumption of the fan drive. Mathematical models for computer calculation are presented. Numerical studies of the influence of the pipeline diameter and the air mixture composition on the power consumption of the fan drive are presented. It was determined that with an increase in the diameter of the pipeline from 0.15 m to 0.175 m and a change in the mixture concentration μ = 0.228 ÷ 0.338 for a serial receiving chamber, the fan drive power decreases from 10.3 kW to 5.79 kW.
The raw cotton entering volume computational and numerical study of the vertical-spindle cotton harvester receiving chamber
Authors: Yuldashev Abdurahim , Kuldoshev Davronbek , Djuraeva Nargiza , Temirov D
Published: June 2021

The article presents a computational-and-numerical study of raw cotton entering the receiving chamber per one second. Numerical calculations were conducted of the change in the volume of raw cotton entering the receiving chamber depending on the yield ripeness and the completeness of the machine harvest. The volume of raw cotton entering the receiving chamber during cotton harvesting was determined, depending on the width of the cotton row spacing. The calculation results showed that for a serial receiving chamber, the volume of cotton filling the receiving chamber should not exceed 0.0031 m3 per second; otherwise the receiving chamber is clogged, and the loss of cotton to the ground increases.
Combination machine for soil preparation and sowing of gourds
Authors: Chuyanov Dustmurod , Shodmonov Golib , Ergashov Gayrat , Choriyev Islom
Published: June 2021

The purpose of the study is to substantiate the method and design scheme of a combined machine for preparing the soil and sowing melons. The authors propose a new method of soil preparation and sowing, as well as a machine for its implementation. The basic principles and methods of classical mechanics, mathematical analysis, and statistics were used in this study. The method of preparing the soil and planting gourds provides a combination of the following technological processes: the turnover of the layers of the upper layer of soil, the sowing area to the left and to the right, shallow tilling the soil of the field with the left and right sides of the sowing area, deep tillage seeding areas with simultaneous formation of irrigation furrows and the local application of fertilizers, soil preparation for sowing in line sowing and sowing seeds of melons. The machine consists of lister housings installed along the axis of symmetry of the unit, flat cutters, parallel-type deep-diggers, furrowers, coulters for fertilizing, and a sowing device. It was found that preparation of soil for sowing and planting of melons with a minimum expenditure of energy is provided by the width of Lusternik buildings 86 cm, the width of tillers and cultivators, respectively, 45 and 33 cm, the longitudinal distance between the body and the plane of 35 cm between the cultivators of 42.3 cm, and longitudinal spacing of the chisel cultivator and sowing device 110 cm.
Technology and machine parameters for preparing the soil for sowing cotton
Authors: Toshtemirov Sanjar , Mustafayev Serobjon , Xo'jayev Alham , Mamatkulov Isomiddin , Boboev Farrukh
Published: June 2021

The study aims to justify the design scheme and main parameters of the combined aggregate for soil preparation for cotton sowing on ridges. The authors have developed the technology of soil preparation for cotton sowing on ridges and the aggregate for its implementation. The technology and design scheme of the developed aggregate are presented. The unit consists of a mouldboard deep loosener with a sloping rack and a ridge maker. The basic principles and methods of classical mechanics, mathematical analysis, and statistics were used in this study. The optimum constructive scheme of combined aggregate is grounded. It was established that to provide formation of new ridges instead of existing ones on fields without stems of cotton with the required degree with minimum power consumption working surfaces of inclined deep looseners equipped with mouldboards and rippers should be turned to each other and shifted relative to each other in a longitudinal plane. The formation of ridges to the required degree with minimal energy input is ensured at a width and length of the subsoiler's chisel, respectively 5 and 20 cm, the width of the wing width 21 cm, wing length between 47 and 49 cm, minimum longitudinal spacing between subsoilers 35 cm.
Irrigation regime Influence on the growth and seedlings development of common fake chestnut (Aesculus hippocastanum L.) and Japanese safflower (Sophora japonica L.) in the highways landscaping
Authors: Ubaydullaev Farxod , Xoliqov Alisher , Xudaybergenov Sardor , Pulatova Tojinur
Published: June 2021

It is important to accelerate the growth of seeds and seedlings when growing seedlings in forests and orchards in the landscaping of roads and residential areas. One of the effective methods is irrigation in the complex of agro-technical measures to improve the nursery. This shortens the growing time of seedlings and saplings of tree and shrub species, increases their quality while reducing labor costs per unit area.
Effects of electrophysical processing on the development of vine root roots
Authors: Berdishev Abdurahim , Markaev Nuriddin , Hasanov Jamol
Published: June 2021

The article discusses the possibilities of electrophysical methods to increase the efficiency of grape seedling cultivation and increase root development in seedlings by 95-97% when exposed to the electric field strength of 16.64 V / m and exposure for 12.24 hours. The possibility is explained in practical and theoretical terms. However, experimental data and various electrotechnologies aimed at increasing the efficiency of root formation and development by 15-20% in grape cuttings treated for 12 and 24 hours at 16 and 64 V / m of electric field strength are presented.
Kinematic characteristics of the car movement from the top to the calculation point of the marshalling hump
Authors: Saidivaliev Shukhrat , Bozorov Ramazon , Shermatov Elbek
Published: June 2021

Introduce analytical acceleration formulas that are derived from the classic d'Alembert principle of theoretical mechanics for high-speed sections and sections of retarder positions; show the possibility of determining the instantaneous car speeds in each section of the marshalling hump according to the formulas of elementary physics both for high-speed sections and for sections of retarder positions; provide formulas for determining the time of movement of a car with uniformly accelerated and/or uniformly retarded motion of the car on the inclined part of the hump, as well as in areas of retarder positions. Research methods: The classic d'Alembert principle of theoretical mechanics is widely used in the paper. Main results: For the first time, the results of constructing a graphical dependence of the estimated height of the marshalling hump over the entire length of its profile are presented in the form of a decrease in the profile height of each section of the inclined part in proportion to the slope of the track. The results of constructing graphical dependences on changes in the speed and time of movement of a car along the entire length of the inclined part of the marshalling hump are fundamentally different from the existing methodology, where, for example, curves of medium (rather than instantaneous) speeds of a car are built. The proposed new methodology for calculating the kinematic characteristics of the car movement along the entire length of the hump allows an analysis of the mode of shunting car at the marshalling humps.