bluuebunny/crossref_metadata_2025 huggingface dataset:
Dispersion of conservative impurities in rivers: implications for compliance with environmental standards
Authors: Salokhiddinov Abdulkhakim , Savitsky Andrey , Khakimova Poshoazimkhon , Ashirova Olga
Published: August 2023

The research goal is to understand the mechanisms of transport and transformation of conservative impurities in river flows and provide practical solutions to ensure compliance with environmental standards. The need to close the system of equations and make it suitable for solving practical problems caused the addition of equations of motion with empirical regularities. We use an approach based on fundamental equations of hydrodynamics. The main task of mathematical transformations of the fundamental equations was: a) considering the variability of the turbulent exchange coefficients along the flow cross-section. b) addition of the obtained equations with empirical regularities linking the flow characteristics with the turbulent exchange coefficients. c) mathematical transformations were performed to obtain a group of closed equations for which approximate solution methods are known and developed. The best empirical regularities in determining the turbulent exchange coefficients were selected by applying a closed mathematical model. For each desired variable, we obtained an equation of the evolutionary type, which lends itself well to algorithmization. The schemes presented in the article allow us to design computational algorithms using classical approaches to solving impurity transfer equations with variable coefficients of turbulent exchange.
Method for regulation of permissible irregularity of brake forces on front axle
Authors: Kasimov Omil
Published: August 2023

It is justified to evaluate the car's stability during braking, not only from the ratio of braking forces but also from their absolute value. Because the ratios of the braking forces do not accurately characterize the maximum value of the turning moment from the unevenness of the braking forces, on which ¬the stability of the car ultimately depends. Depending on the braking system's characteristics, emergency braking can occur either without wheel blocking or with a certain combination of blocked wheels; due to significant differences like braking, the permissible unevenness for the corresponding type of braking should be determined according to different criteria. An algorithm for determining the permissible unevenness of the braking forces on the wheels of the front axle of the car when braking with locked rear wheels and when braking without blocking the wheels has been compiled.
Adaptive power supply system in plot with artificially complex profile
Authors: Yakubov Mirjalil , Sagatova Muborak , Norjigitov Sayfuddin , Saidivaliev Saidaziz
Published: August 2023

The paper deals with the issues of energy saving in the railway section, which has a tunnel with a double longitudinal slope, which limits the capacity of trains due to a decrease in the rated voltage by more than 10%, which negatively affects thermal and transient electromechanical processes. The practicality of voltage regulation using the existing installation of series compensation is shown; it is proposed to use an additional installation of parallel reactive power compensation, with automatic voltage regulation of the power transformer under load. The principle of self-tuning adaptive regulation is applied, establishing the optimal power supply mode according to the criterion of minimum losses, which has high reliability and cost indicators of traction power supply.
Upheaval buckling of underground pipelines of complex configuration located in liquefied soils
Authors: Mardonov B. , Mirzaev I. , Nishonov N. A. , An E. V. , Kosimov E. A.
Published: August 2023

The problem of loss of stability of underground pipelines with a middle part in the form of a straight or П-shaped part located in liquefied soils is considered in the article. The pipeline lifting process occurs under the action of buoyancy force in the liquefied soil zone and then under the action of the longitudinal compressive force that appears due to the temperature of the transported product and its pressure. The problem is solved by the finite element method. The results are presented as a table and graphs of changes in the values of transverse displacements along the coordinate depending on the pipeline geometric characteristics and the soil rheological properties. It is established that the П-shaped part is a damper against pipeline buckling.
Production estimate of technological operations duration in railway transport
Authors: Mukhamedova Ziyoda , Ergasheva Zakhro , Barotov Jamshit , Ergasheva Vasilya , Abdullaev Rustam
Published: August 2023

Purpose: To stabilize the departure of trains on schedule, to do this, to justify the size of the factor of unevenness taken into account when normalizing the duration of the main technological operations with the compositions of container block trains for departure at the junction stations. Methods: From the existing automated systems, statistical data were collected and processed using MS Excel software, and the mathematical expectation, standard deviation, and dispersion of the duration of operations with the block train at the departure station were determined. The hypothesis about the normal law of distribution of the random variable of the duration of each of the main operations at the station was tested by the “chi-square” goodness-of-fit test. Results: The distribution of the random variable of the duration of operations at the station is described using the normal distribution law; a technological schedule for processing the composition of the container block train on the tracks of the railway junction station was built. Practical significance: Practical recommendations will reduce the technological norms for the processing time of a container block train on the tracks of a railway junction station. As a result, the processing time for block trains on departure on the station tracks will be reduced from 154 minutes to 132 minutes, which will save time by 22 minutes.
Choice of garbage trucks with rational parameters according to criterion of minimum operating cycle time
Authors: Khankelov T. K. , Mukhamedova N. B.
Published: August 2023

In conditions of limited commercial information on costs and rational costs, machines' efficiency and rational parameters at the stage of their manufacturing can be established based on an analysis of technical and operational indices. On this basis, the technical efficiency of the machine can be established. The corresponding technical and operational indices are calculated based on known technical parameters and operating conditions of the machine. These are such indices as specific energy consumption (kVt∙h/m3), material consumption (t∙h/m3), productivity (m3/h), output per worker (m3/w∙h), and several generalized indices derived from the indicated ones. The choice of a rational solution is based on single-criteria optimization (on the one-criterion analysis).
Application of the method of direct mathematical modeling to diamond-shaped contact lines
Authors: Amirov Sulton , Karimov Islom , Abduazimova Iroda
Published: August 2023

The article describes the application of the numerical method to the investigation of the dynamic interaction of contact lines with current collectors of electric rolling stock (ERS).

The law of joint movement of the runner and the contact wire shall be established. If agap is recorded at anystage, the pressure value is set to zero. From this point on, the flux and contact wire are modeled independently. The contact wire shall be touched by the current collector by the clearance δ. As arule, the introduction into contact is accompaniedbytheintroduction of acurrent collector into the contact wire, which is characterized by negative clearance δ<0. To compensate for the introduction atthepointof contact, there must be an additional «push» force defined by the condition of zero clearance at the end of the stage.
Mathematical model for prediction of cargo flow during the construction of the railway line Uzbekistan - Kyrgyzstan – China
Authors: Umarov Khasan , Tursinaliyeva Yulduz , Khurramov Islom , Shayakhmetov Saulet
Published: August 2023

The purpose of this work is to study a mathematical model for predicting freight traffic during the construction of a new railway line Uzbekistan - Kyrgyzstan - China, taking into account the considered economic factors. The proposed algorithm for constructing a predictive mathematical model of freight traffic during the construction of a new Uzbekistan-Kyrgyzstan-China railway line will make it possible to choose technical solutions that determine the operation of the Uzbekistan railway in the future, as well as the best options for strengthening its capacity in the future.
Creation of special compositions based on butadiene-nitrile elastomers for diesels
Authors: Mamayev Sherali , Ibadullayev Axmadjan , Nigmatova Dilnoza , Teshabayeva Elmira , Tursunaliev Mukhsinjon
Published: August 2023

In the article, it was determined that furan oligomer added to the composition causes additional structuring in the process of vulcanization, and as a result, the density and hardness of the vulcanization network in the composite increases, and the value of the relative length decreases. It was shown that the optimal amount of furan oligomers in the composition of rubber compounds is equal to 10 weight units per 100 weight units of rubber.

With the inclusion of the secondary product of acetylene production in the elastomer compositions, it was found that the amount of carbon-rubber gel and the vulcanization network increased, and the level of vulcanizate shrinkage decreased, which was shown to be mainly due to the presence of oligomeric components on the surface of carbon particles. It is shown that the inclusion of this raw material in elastomeric compositions based on butadiene nitrile rubber increases the interaction at the “rubber-filler” boundary and the formation of additional bonds between rubber macromolecules and functional groups of the oligomer, and as a result, the overall technological and technical properties of the compositions are improved.
Mathematical modeling of wastewater treatment facilities of transport enterprises
Authors: Umarov Uchqun , Arifjanov Aybek , Rizayev Abdumalik , Umarova Dinara
Published: August 2023

Wastewater is purified by mechanical, biological, physicochemical and chemical methods. Mechanical treatment plants are the main stage of treatment and remove most of the harmful substances contained in wastewater. The mechanical treatment facilities include a sand trap, a sump, a hydrocyclone, a grid, etc. Among them, the most common and basic design are sumps, which are divided into types according to design and function. In this article, a new mathematical model for calculating vertical sediments used in local treatment for small enterprises has been improved, and design parameters have been calculated. Theoretical studies of the proposed sump were carried out on the basis of molecular kinetic theory, and its accuracy was verified by the author in experimental tests. In the sump, an expression for the distribution of the concentration of suspended solids in wastewater was found. Thus, a filter structure with a filtration efficiency above 60% was created.
Possible problems of transport electrification in Tashkent
Authors: Radkevich M. , Gapirov A. , Ochildiev O. , Pochuzhevskiy O.
Published: August 2023

The purpose of this article is to assess the process of electrification of transport in Tashkent and forecast some of the possible consequences of this process until 2027. It has been established that with the growth of transport electrification, it is possible to achieve hazardous concentrations of particulate matter in the atmospheric air of the city. A significant relative increase in ferrous and non-ferrous metal waste (by 1.3...3.6 times), as well as scrap tires (by 1.5 times) is also predicted.
Prediction of the stress - strain state of the bogie frames of shunting locomotives using the finite element method
Authors: Yusufov Abdulaziz , Khamidov Otabek , Zayniddinov Nuriddin , Abdurasulov Sherzamin
Published: August 2023

The article is dedicated to topical issues of control and calculation of residual life of the bogie frame of shunting locomotives operated on the railroad of Uzbekistan. Mathematical methods for calculating the residual life of locomotives are presented in the article and the expediency of extending the service life of shunting locomotives at the earliest stage of their development is substantiated. The outcomes were obtained with the help of the Solid works software environment which allows analyzing calculations and revealing forces acting on the bogie frame of locomotives. The mathematical description of forces acting during the bogie frame of locomotives is also presented. The methods of bogie frame residual life forecasting and service life extension of shunting locomotives are investigated.
Mathematical modelling of inulin drying and extraction processes
Authors: Ergasheva Z. K. , Safarov J. E. , Sultanova Sh. A.
Published: August 2023

In this study, a natural extract of Jerusalem artichoke was studied. The physicochemical properties of the concentrate obtained from the Jerusalem artichoke plant were studied. In mathematical modeling, there are methods of experimental statistical modeling. In this case, the results of experiments obtained on this installation are used to create a mathematical model of the technological process. The flow motion was studied for solution analysis. The importance of studying flow motion lies in determining the parameters that need to be taken into account in the simulation.
Swirling flow for dust capture
Authors: Badalova D. A.
Published: August 2023

An apparatus is proposed that operates on the principle of gas purification from dust in counter swirling flows. In order to select the optimal design of the apparatus for trapping cellulose acetate particles from the exhaust air, the granulometric composition of the entrained material was determined. The differential curve of size distribution of cellulose acetate particles is given. The paper presents the results of the use of apparatuses with counter swirling flows for capturing dust of cellulose acetates from the exhaust pipes of silo towers. The possibility of using this type of apparatus as an industrial vacuum cleaner is considered. A diagram of an apparatus with counter swirling flows is given, and the principle of operation of an apparatus with counter swirling flows and the conditions that ensure the safety of the apparatus are described.
Investigation of the interaction of hydraulic parameters of the channel in the filtration process
Authors: Arifjanov Aybek , Jurayev Sherali , Qosimov Tokhirjon , Xoshimov Sardor , Abdulkhaev Zokhidjon
Published: August 2023

One of the most important and complex issues in the design of soil drainage channels is the issue of correct accounting of the filtration process. It is necessary to take into account hydraulic parameters and soil composition of existing channels in order to reduce filtration flow rate in ditches with uncoated soil. The article shows how to choose its theoretical basis for reducing the filtration flow rate correctly. Hydraulically convenient design is one of the current problems in the design of canals. This can be achieved by reducing the wet perimeter of the channel to reduce the filtration process in the channel. The article recommends that measures to reduce the filtration process be implemented during the construction or reconstruction of canals, without dismantling and rehabilitating existing canals. Field research was conducted on the North Fergana main canal. In order to study the filtration processes, measurement works were carried out on the PK 396+00, PK 497+01, PK 688+7, PK 692+6, PK 694+6, PK 697+00 pickets crossing the 2-section of the channel in the city of Namangan. In addition, the article developed recommendations on the methods and procedures for the application of bentonite clay from the Lagon betonet clay deposit of the Fergana region to the bottom of the channel in order to reduce the filtration process that occurs in the canal area. According to the results of the study, in the range from PK 411 + 00 to PK 426 + 74, filtration consumption was higher than other pickets.
Model of field robot manipulators and sensor for measuring angular displacement of its rotating parts
Authors: Baratov Rustam , Mustafoqulov Almardon
Published: August 2023

This research aims to measure and control the angular change of rotation mechanisms of (energy-saving) robotic manipulators used in agriculture to develop digital farming, energy saving, and quality product harvesting. The novelty of this research is that different processes and images are placed in a special processor for processing, and this robot processes the image according to the size of the tomato plant and tomato and tries to harvest the crop. This study presents the electromagnetic angular displacement sensor and its technical characteristics. The existing electromagnetic angular displacement sensors have been thoroughly analyzed and compared with other types of sensors. The reason for the low sensitivity of the electromagnetic angular displacement sensor has been investigated, and some technical modification to the existing sensor has been made. The magnetic circuits of the electromagnetic sensors have been analyzed. A method is proposed for expanding the range of angular measurements up to 180 degrees and increasing the sensitivity of the electromagnetic sensor without compromising the measurement accuracy. This, in turn, allows high-precision control and measurement of rotating mechanisms of all types of mechatronic systems and agricultural robots.
Dynamic correction in manipulator control systems based on intelligent linear motion mechatronic module
Authors: Rakhimov T. O. , Rakhmanova E. E. , Erkinov S. M.
Published: August 2023

Robotic complexes and robotic manipulators are widely used in the management of various objects and processes of control systems; their performance is directly related to the execution element. Electromagnetic actuators of multi-function control systems are structurally created separately for each adjustment body and lead to system complexity. To solve these problems, improve the executive system's weight-gauge indicators, and simplify the structural schemes, implementing intelligent mechatronic modules that perform linear and rotational movements in space coordinates is one of the urgent tasks. In this article, dynamic correction in manipulator control systems built based on an intelligent linear motion mechatronic module is considered. In manipulator control systems, the use of intelligent mechatronic modules in dynamic correction for manual and semi-automatic control manipulation systems that do not have a feedback channel for forces and moments and the relevance of the handle movement and manipulation objects with such a selection of the forces and moments vector m developed by them was seen. The article presents mathematical models for calculating vector components based on the current values of the generalized coordinates of the manipulator, their speed and acceleration, and the selection of the vector of forces and moments m developed by the intelligent mechatronic modules of the manipulator.
Analysis of stress-strain state of bogie frame of PE2U and PE2M industrial traction unit
Authors: Abdurasulov Sherzamin , Zayniddinov Nuriddin , Yusufov Abdulaziz , Jamilov Shuhrat
Published: August 2023

This article presents the results of the theoretical analysis of the stress-strain state of the industrial traction unit PE2U and PE2M frame. The stress-strain analysis was performed using the finite element method in SolidWorks Simulation software. The analysis results are necessary to estimate the residual resource of the traction units at the end of their service life and extend their service life. According to the requirements of the state standards, to extend the service life of the rolling stock load-bearing constructions, the stress-strain state of these constructions should be studied. A 3D model of the bogie frame was built using SolidWorks software to evaluate the strain-deformation state. Using the SolidWorks Simulation program, the stress-strain state of the bogie frame was evaluated using the finite element method based on the Palmgren–Miner–Mises theory. All static and dynamic loads in use affecting the bogie frame are taken into account.
Linear plow with disk angle
Authors: Мaiviatov F. M. , Shomirzaev M. Kh. , Chorieva D. N. , Rashidov N. Sh. , Ochilov S. U.
Published: August 2023

The study aims to substantiate the design scheme of a linear plow with a disk angle. The authors have developed a linear plow with a disk plow for smooth, furrowless plowing. The proposed plow has disc lugs, screw housings, and guide plates. The technological scheme turnover of polygonal layers formed by disk pre-plates, the scheme mutual arrangement housings and guide plates, and the general view laboratory-field installation for conducting experiments are given. During the experiments, the degree of sealing plant residues, height irregularities on the surface arable land, and the traction resistance device were used to evaluate the performance plow. To ensure the required quality work with minimal traction resistance, a linear plow must be equipped with disc pre-lugs installed in front housings along their field cut line. When installing a disk prep lug with a working surface facing towards the turn formation, the degree sealing plant residues and the height of irregularities is 92-95% and 4.3-5 cm, respectively, which fully complies with agro technical requirements.
Parameters of mini straw grader
Authors: Мaiviatov F. M. , Karimov R. R. , Musurmonov I. E. , Choriev R. M. , Saparov Sh. Sh.
Published: August 2023

The purpose study is to substantiate the parameters of a mini straw shredder. The diagram rotor of a cone-shaped shredder is given. The basic laws of theoretical mechanics and mathematical analysis were used in theoretical studies to substantiate the parameters mini shredder. Single-and multifactorial experiments were carried out when determining the optimal parameters mini shredder. In theoretical studies, analytical links were obtained to determine the length of the mini straw grader knife, the slope angle, its base, and the force required to cut the straw. According to the results of studies, the degree of grinding salmon and energy consumption depended mainly on the length blade, the mass balancing truck, and the slope angle blade. It is established that to ensure the required fullness of grinding with minimal energy consumption, the length knife should be within 87.66-88.38 mm, the weight of the balancing weight should be 0.0368-0.0536 kg, and the angle of inclination of the knife 2848º.
Temperature dependence of width band gap in Inxga1-Xasquantum well in presence of transverse strong magnetic field
Authors: Erkaboev U. I. , Sayidov N. A. , Negmatov U. M. , Rakhimov R. G. , Mirzaev J. I.
Published: August 2023

This article investigated the temperature dependence of the width band gap in InxGa1-xAs quantum well in the presence of a transverse strong magnetic field. A new method was proposed for determining the width band gap of GaAs/InxGa1-xAs heterostructures based on a InxGa1-xAs quantum well in the presence of a magnetic field and temperature. An analytical expression is obtained for calculating the width band gap of a rectangular quantum well at various magnetic fields and temperatures.
Facile synthesis of vinyl esters of aromatic carboxylic acids with participation of 2-chloro-4,6-dimethoxy-1,3,5-triazine
Authors: Parmanov A. , Nurmanov S. , Tursunov Sh. , Erkhanova Yu.
Published: August 2023

In this work, the reaction of derivatives of benzoic acid containing substituents in the aromatic ring (1a-o) with 2-chloro-4,6dimethoxy-1,3,5-triazine (4) in the presence of N-methylmorpholine (6) has been synthesized active triazine esters of carboxylic acids (3a-o). These compounds obtained in the presence of potassium butylate (7) in reaction with vinyl acetate (2) have formed vinyl esters of corresponding aromatic carboxylic acids (5a-o). The electronic effect of the substitutor in the aromatic ring affects on carrying out of the reaction and the nature of obtained products. The structure of the synthesized vinyl esters of aromatic carboxylic acids was confirmed by FT-IR, 1H_NMR, 13C-NMR, and LC/MS spectral analysis, and some of their physical constants were determined.
Mechanical properties of concrete reinforced with basalt fibers
Authors: Razzakov S. , Martazaev A.
Published: August 2023

In the article, the compressive strength, tensile strength, and residual tensile strength of fiber-reinforced concrete reinforced with basalt fibers were studied based on the experiment. Basalt fibers 10 mm and 30 mm in length and 0.017 mm thick were added at 0.0%, 0.1%, 0.2%, and 0.3%. The samples were stored at room temperature and relative humidity above 75%, and the samples were tested on days 7 and 28. The addition of fibers increased the compressive strength, tensile strength, and residual tensile strength of concrete and changed its brittle behavior to a more ductile one. When 10 mm length basalt fibers were added to concrete in amounts of 0.1, 0.2, and 0.3%, the tensile strength was 2.35 MPa, 2.38 MPa, and 2.40 MPa, respectively. When 30 mm length basalt fibers were added to concrete in amounts of 0.1, 0.2, and 0.3%, the tensile strength was 2.22 MPa, 2.32 MPa, and 2.36 MPa, respectively. The compressive strength of prism samples reinforced with basalt fibers increased by 10-20% compared to ordinary concrete.
Mathematical modeling of torsional vibrations of the wheel-motor unit of mains diesel locomotive UZTE16M
Authors: Mamaev Sherali , Anna Anna , Tursunov Shukurali , Nigmatova Dilnoza , Tursunov Tokhir
Published: August 2023

The article considers methods for studying torsional vibrations of the wheel-motor block of a diesel locomotive UZTE16M. The diesel locomotives in question were modernized at the structural enterprise “O’ztemiryo’lmashta’mir” (Machine building and repair in Uzbekistan Railways company) under the joint-stock company “O’zbekiston temir yo’llari” (Uzbekistan railways). The authors of the article developed a dynamic model for the analysis of torsional vibrational movements that occur in the traction transmissions of the UZTE16M diesel locomotive, taking into account the geometric dimensions of the electric traction motors of the main locomotives and the degree of their wear.

Based on the model of the wheel-motor block of mainline locomotives, differential equations of the torsional-vibrational motion of traction gears are obtained in the form of Lagrange equations of the 2nd kind. The results of numerical studies of the amplitudes of torsional vibrations of the wheel-motor block of the UzTE16M locomotive at different frequencies are presented. All calculations were performed in the MATHCAD 15 environment.
Improving maintenance system for controlled asynchronous electric drives of electric locomotives based on their diagnosis
Authors: Yakubov M. S. , Turdibekov K. Kh. , Norzhigitov S. A. , Sagatova M. A.
Published: August 2023

The article assesses the reliability of improving the maintenance of the control system of an asynchronous traction electric drive of an electric rolling stock with a rectifier-inverter converter based on power IGBT transistors, increasing the power factor in traction mode and regenerative braking.
Logistic indicators of locomotives of diesel traction on high-speed section of the railway
Authors: Ablyalimov Oleg , Julenev Nikolay
Published: August 2023

The results of a theoretical study evaluating the effectiveness of using Uzbek diesel locomotives of the UzTE16M3 series during the non-stop movement of freight trains on the hilly-mountainous high-speed section Marokand - Kattakurgan of the Uzbek railway are presented. The reference point for the implementation of this assessment was the mathematical model of the movement of a freight train developed by the authors and the algorithm for performing traction calculations, which are prerequisites for substantiating the numerical values of the parameters of the logistic indicators for the process of railway transportations of goods in real conditions of the organization of operation. The authors obtained the parameters of logistics indicators in the form of numerical tabular values and graphical dependencies, and the corresponding regression equations were proposed to calculate the indicators of transport logistics. The data obtained by the authors can be used by specialists of the locomotive depots “O’zbekiston temir yo’llari” JSC, whose production activities are related to the issues of forecasting and normalizing the consumption of full-scale diesel fuel by diesel locomotives on the hilly-mountainous, of hi high-speed sections of the Uzbek railways.
Modeling of the process of mechano activation of filler particles in polymer composites
Authors: Ziyamukhamedova Umida , Evlen Hatice , Nafasov Jasurbek , Jalolova Zilola , Turgunaliyev Elbek , Rakhmatov Erkin
Published: August 2023

The article presents the results of the study of the filler particles activation mechanism in the production of composite polymeric materials modified by mechanical activation. The studies were conducted in simulated conditions of motion of filler particles taking into account the trajectory of motion during milling in progressive-rotational activation units using analytical expression of velocity distribution of each filler particle in the composite material.
Experimental study of deformation and stability of dams built of phosphogypsum under seismic impacts
Authors: Fayziev Khamidxon , Sultanov Takhirjon , Mambetova Lobar , Sharipov Ravshan , Yarashov Javlon
Published: August 2023

The article presents the results of experimental studies of the model behavior under seismic influences. The conditions for ensuring the seismic resistance of phosphogypsum dams were investigated and established by testing the models on a vibration platform. The purpose was to study the deformability and stability of slopes of a given configuration built of phosphogypsum and to substantiate the possibility of using phosphogypsum to construct enclosing dams of sludge tanks located in seismic regions. The tests were conducted on small-scale models on a horizontal vibration platform in laboratory conditions. The methods of research using the vibration platform and the accepted modeling parameters were discussed. Dihydrate phosphogypsum with an optimal moisture content of 22-23% was used to construct the models. In total, 2 groups of prototypes were tested; they differed from each other only in the slope ratio. Models of the 1st group were tested without water. Models of the 2nd group were tested after wetting their materials to an average of 32 - 40%. To do this, water was filled in into the tank to the crest level, and the models stayed in this state for a week. Each model in both groups was tested for dynamic impacts with an earthquake intensity of 6-9 points. As a result of the studies on the seismic stability of dam fragments made of phosphogypsum, it was established that the enclosing dams of sludge tanks (built from phosphogypsum with optimal moisture content and its layerby-layer compaction up to 1.25 g/cm3, when the slope ratio was no steeper than m=3), have the necessary seismic resistance during earthquakes with an intensity of 7 -9 points. Based on the generalization of the data of model studies, the diagrams of the acceleration distribution in the height of the models were obtained. The diagrams of the acceleration distribution in height obtained in the experiments indicate the amplitude attenuation of the model vibrations from the base to the crest zone.
Calculation of evaporative-radiant cooling of recycled water in summer air-conditioning systems
Authors: Usmonov N. O. , Hazratov A. G. , Usmonov J. Y.
Published: August 2023

The paper describes the calculation of evaporative-radiant cooling of recycled water in summer air-conditioning systems. A differential equation for the heat balance of water flowing down an inclined plane is derived. One possible way of increasing the efficiency of air conditioning systems based on cooling water by adiabatic evaporation in the air flow is using night-time evaporative cooling of the water, followed by daytime cooling in insulated storage tanks. The temperature of the water chilled in this way is 3-4 ° lower than the temperature of the water chilled during the day, and the final water temperature is close to the saturation temperature of the outside air. The equations for calculating mass transfer coefficients, radiation, and heat transfer coefficients of an insulated bottom of an evaporative-radiant water-cooling unit are given. Based on the Mathcad program and the result of the calculation, the dependence of the final water temperature on the initial water temperature is obtained. As a result of the calculation, the specific heat capacity of the evaporative radiant water-cooling unit for the production of free cooling is determined.
Experimental tests of submersible vane pumps
Authors: Glovatskii Oleg , Ergashev Rustam , Nasirova Naira , Rashidov Jaloliddin , Kholbutaev Boybek
Published: August 2023

The technical task of creating new designs of submersible vane pumps is to maintain stable operating parameters and increase the productivity of the pumping station with periodic regeneration and sediment removal. The pumping well station contains an outer chamber and an inner chamber, in which a pumping unit is installed, and pipelines are connected to the lower and upper pools. In the structure under study, the upper parts of the outer and inner chambers are equipped with a sealed head, and the lower part of the outer chamber is equipped with a stopper. The side surface of the inner chamber is made of elastically deformable material. An elastic pipeline with an ejector at its end with curvilinear helical grooves on the inner surface of the nozzle part of the ejector is connected to the pipeline connected to the tailpipe, and water level meters are installed in the outer chamber. The technique of balance testing of new designs of submersible vane pumps was applied because the existing technology is insufficient for correct balance tests. Research methods involve the design of the impeller, which is rigidly mounted on the shaft. The methodology has been adjusted to apply to multistage pumps with different types of impellers. In the energy balance of this pump, the power losses due to friction in the individual axial support of the impeller are additionally determined. Experimental work was carried out, resulting in measurements of the hydrodynamic moment acting on the guide vane grate. Experimental work was carried out on a vertical stand with new pump impellers ETsV-10-120-40 and with a service life of 1 year. Parametric tests made it possible to determine the change in the external parameters of the pump depending on changes in its operating conditions and network characteristics.
Wear resistance of gear teeth in the presence of slippage between gear teeth and during rolling
Authors: Ishmuratov Hikmat
Published: August 2023

This article gives a brief overview of the fracture of contacting parts under the influence of circumferential force in meshing accompanied by rolling and slipping during plastic deformation.
Polymer-bitumen composition for insulation purpose
Authors: Yoqubov Bekhzod , Ibadullaev Akhmadjon , Yoqubova Dilnora
Published: August 2023

The aim of the work is to develop a polymer-bitumen insulating composition based on petroleum bitumen and secondary products of the chemical industry. Investigated the physical and chemical properties of the secondary product of the production of polypropylene, the adsorbent of the oil and gas industry, the powder of crushed tires. It has been established, the technology of their introduction into the compositions and their influence on the technological and physical-mechanical properties of polymer-bitumen compositions has been investigated, and their optimal content has been determined.
Development of a mathematical model of a frequency-controlled electromagnetic vibration motor taking into account the nonlinear dependences of the characteristics of the elements
Authors: Toirov Olimjon , Khalikova Malika , Jumaeva Dilnoza , Kakharov Sergey
Published: August 2023

The wider application of vibration machines (VM) with electromagnetic motors (EMVM) in various industries, including in vibration test benches for telecommunication devices and equipment has been studied in the paper. Difficulties associated with maintaining their productivity and efficiency at a given level are largely hindered. These factors mainly depend on the determination of the degree of influence of the nonlinearities of the input-output characteristics on the output values of the VM, the possibilities of tuning into the resonance mode, and the control of the output values while ensuring the energy-saving mode of operation of the EMVM. The mathematical model has been developed for a frequency-controlled EMVM taking into account the nonlinear dependencies of the characteristics of the elements, which makes it possible to determine the most accurate amplitude of oscillations of the EMVM working body when passing through resonance, observed with changes in the voltage frequency. The analysis of the physical processes of the influence of nonlinear elements of the electric circuit of the EMVM on the electromagnetic quantities and the derived analytical expressions of these nonlinearities, which make it possible to determine the harmonic composition of the current of the EMVM winding, are made. The system of vector control of the EMVM and the inclusion of a mathematical model of the engine into the control system have been developed, which will allow calculating the frequencies of free oscillations of the working body for tuning into the resonance mode.
Modern state of the energy sector of Uzbekistan and issues of their development
Authors: Allaev Kakhramon , Toshov Javokhir , Toirov Olimjon
Published: August 2023

The data on the current state of the energy sector in Uzbekistan are presented. The need to diversify the structure of the republic’s energy balance is shown to ensure the energy security of the state in the medium and long term. The development of the energy sector is extremely important for ensuring sustainable economic growth and solving social problems of the state; as well as the development and modernization of the electrical system, the oil and gas sector, the construction of a nuclear power plant and a gradual transition to renewable energy sources are strategic directions for the development of the fuel and energy complex of Uzbekistan. It is argued that the construction of a nuclear power plant in Uzbekistan is not only advisable, but also necessary. The issues of the prospects for the development of renewable and nuclear energy sources in Uzbekistan, issues of investment and system costs with different shares of their participation in electricity generation are considered. It has been developed and shown that in the future, based on the symbiosis of renewable nuclear energy, by the middle of the 21st century, conditions for carbon-neutral energy can be formed in the economy of Uzbekistan.
Non-volatile phototransistor based on two dimensional MoTe2 nanostructures
Authors: Saidov Kamoladdin , Butanov Khakimjan , Razzokov Jamoliddin , Mamatkulov Shavkat , Fang Dong , Ruzimuradov Olim
Published: August 2023

We fabricate field-effect transistors (FETs) from low-layer molybdenum ditelluride (MoTe2) in the nanometer range and study its optoelectronic properties. In particular, we investigate the mechanisms of photocurrent generation in MoTe2 FETs using gate and bias-dependent photocurrent measurements. The results obtained show the photocurrent effects and signals generated in the MoTe2-electrode junctions, which identify the effect of amplifying the photoconductor in the off and on modes. This is different from those conventional MoTe2 FETs, which exhibited a continuous increase in photocurrent with no back gate voltage. These results play an important role in the fabrication of direction dependent field effect transistors based on MoTe2 crystals.
Need Analysis of Parenting Application Based on Riau Malay Culture
Authors: Novianti Ria , Mahdum Mahdum , Suarman Suarman , Noviana Eddy
Published: August 2023

The role of parents in children’s lives has always been significant, but in today’s changing world, parents face new challenges brought about by shifts in society and technology. This study aims to analyze parents’ specific needs for parenting information delivered through technology. The research utilized survey methods and gathered data from 62 parents with children aged 0-6 years in three districts of Riau Province: Pekanbaru, Kampar, and Indragiri Hilir. The analysis of the collected data reveals that most parents prefer digital resources for obtaining parenting information, with Android being the most commonly used platform. The most sought-after information by parents includes positive parenting strategies, interaction skills, and effective communication techniques. Furthermore, parents show a preference for visual and video content when receiving parenting information. It is noteworthy that 51.5% of parents have already utilized parenting applications, but a significant majority (82.3%) remain unaware of any parenting applications based on Riau Malay culture. Parents express the desire for Malay cultural values, which are closely associated with Islam, to be integrated into parenting practices, as it is believed that this approach can effectively instil Islamic values in children.
Case-Study Based in Entrepreneurship Lectures for Teacher Candidates: A Design of Learning Phase
Authors: Sukarno Sukarno , Siswanto Siswanto , Haryati Haryati , Muhlisin Ahmad
Published: August 2023

It is essential to provide entrepreneurship courses to teacher candidates as a provision for when they are already taking part to become teachers. Often, entrepreneurship lectures are not carried out in a meaningful way, and therefore the competencies that should be possessed by students after attending entrepreneurship lectures could be better achieved. This research aims to design entrepreneurship lectures using case study-based learning so that the competencies expected of students can be achieved. This study uses the Fuzzy Delphi method involving 10 experts who are entrepreneurship practitioners with teacher education backgrounds, researchers in the field of education, and lecturers of entrepreneurship courses. The ten experts validated the learning phases and results. Then, the validation was analyzed using fuzzy techniques. The results showed that an agreement was reached on the phases of case study-based learning in entrepreneurship lectures among 10 experts. These phases include (1) case identification; (2) literature study; (3) creation of a roadmap for solving cases; (4) settlement of cases according to the road map; (5) construction of a report of the results; (6) presentation of the report. The six phases are expected to facilitate students to achieve the expected competencies.
Implementing Local Wisdom-Integrated Project-Based Learning Model to Instill Students’ Learning Independence
Authors: Widyaningrum Ratna , Prihastari Ema Butsi
Published: August 2023

Local Wisdom-Integrated Project-Based Learning is an innovative learning that emphasizes complex inquiry-based activities to solve problems. The application of this model supports the attainment of the concept of independent learning, which includes students’ learning on their own initiative in identifying learning needs, formulating learning objectives, identifying learning resources, selecting and determining learning strategies, and evaluating learning outcomes. The aims of this study are: 1) to determine the effect of the model on students’ learning independence, 2) to find out how effective the model is to students’ learning independence, 3) to analyse students’ learning independence, and 4) to analyse the factors that influence students’ learning independence. The research method used in this study is mixed methods with a sequential explanatory design. The sequential explanatory method is a type of mixed method. For this study, the first stage uses quantitative methods, while the second stage uses qualitative methods. The population and the sample are the 6th-semester students, selected through a total sampling technique. The first stage will be implementing the project-based learning model in lectures and testing hypotheses related to the effect of the project-based learning model on students’ learning independence. Learning independence data was obtained through a questionnaire and tested using the paired sample t-test and N-Gain. The second stage is research by collecting qualitative data related to the implementation of the project-based learning model and students’ learning independence. The results of this research are: 1) There is an effect of implementing the project-based learning model on students’ learning independence, 2) The project-based learning model is effective in increasing students’ learning independent, 3) The increase in N-Gain is in the medium category, 4) Factors that influence students’ learning independence include learning motivation, learning facilities, and lecturers’ learning models/methods.
Online Assessment of Primary Students’ Cognitive, Psychomotor, and Affective Domains: Practices from Urban and Rural Primary Schools in Indonesia
Authors: Karta I. Wayan , Farmasari Santi , Ocampo Darrel M.
Published: August 2023

This study intends to describe assessment strategies for young students’ online learning. The participants in this descriptive qualitative study were 15 primary school principals and 35 teachers teaching Years 4 and 5 in urban and rural schools on the island of Lombok, West Nusa Tenggara Province, who volunteered their participation after undergoing comparable procedures. Using operational concepts of assessment of learning for online learning, class observation, and interview were organized. The content and structure validity of the measures were evaluated in accordance with the developmental periods of young learners. The findings showed that the teachers assessed the primary students’ cognitive, psychomotor, and affective domains interactively during the online class meetings, in their portfolio, and through attitude direct observation. Several assessment strategies were advocated to circumvent the shortcomings of online learning. A criterion-referenced evaluation was used to conduct the analysis. The theoretical implications of the findings suggest that the various assessment procedures adopted have decreased the negative washback of online exams; however, further research is required to determine the consistency of the outcomes of online tests with other types of evaluation.
Inclusive Education for Early-Age Blind Children
Authors: Alvi Ria Rizkia , Novianti Ria , Wulansari Betty Yulia , Vikriani Aulia
Published: August 2023

Indonesia is not yet a friendly country for people with disabilities. One of the services needed by persons with disabilities is education. The proper education needs to be applied in special schools are implemented in inclusive schools. Inclusive schools need help with supporting infrastructure that is not yet suitable for early childhood learning. Therefore, we need an accurate picture of developing good facilities and infrastructure. One of them is the concept of “Disability Friendly Schools,” where schools are schools that are friendly to people with disabilities. The method of writing this article is a literature study. This paper aims to explain the concept of inclusive education ideal for blind children in terms of facilities and infrastructure. The result of this discussion is to explain the concept of inclusive education for blind children seen from proper facilities and infrastructure ranging from assessment tools, orientation and mobility, learning/academic aids, visual aids, auditive aids, and physical exercise tools.