bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydraulic research results for cantilever spillway at Hydroelectric power station 2 of Chirchik – Bossuv waterway
Authors: Khusankhudzaev U , Jahonov A 
Published: July 2020

Abstract
To date, in the water sector, such urgent problems of our time as the observed decrease in the reliability and safety of hydraulic structures and their individual elements are highlighted. The level of effectiveness of water distribution management and the timely supply of electricity to consumers depends on the stable operation of the entire hydraulic complex. Water management construction is very material-intensive and requires constant expenditures of material and energy resources to maintain the level of stable operation. However, in the event of an emergency at hydroelectric power station facilities, it is extremely difficult to provide the necessary resources for carrying out restoration work on time. In the practice of hydraulic engineering, various designs of cantilevered spillways have been widely used. Reliability and trouble-free operation of such spillway structures with the conjugation of downstream divers by a jet largely depend on perfection. This article discusses the problems of local erosion in the downstream of hydraulic structures, sets out the results of experimental studies to determine the depth of local erosion behind a cantilever spillway in the outlet channel with recommendations on its end structure.
Evaluation of ASTER DEM and SRTM DEM data for determining the area and volume of the water reservoir
Authors: Khasanov Kh 
Published: July 2020

Abstract
Nowadays, like many other fields, Digital Elevation Models (DEM) are widely used in the field of hydrotechnical engineering. In this study, the vertical accuracy of the Shuttle Radar Topography Mission (SRTM DEM) was compared to Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER DEM) for the area recommended for the construction of the Kyzylsay and Tashtepa water reservoirs in Tashkent region, Uzbekistan. Vertical differences between SRTM and ASTER products were computed the root mean squared error (RMSE) compared to GPS data. Results show that SRTM based measurements of ground control points (GCPs) exhibit RMSE of 4.262 m while ASTER DEM based measurements exhibits and RMSE of 3.693 m for the Toshtepa Reservoir located in the plain, and for the Kyzylsay reservoir located in the mountains, RMSE results show that 12.82 m for SRTM, 15.77 m for ASTER. There are SRTM DEM outperforms ASTER DEM in detecting vertical accuracy. This indicates that ASTER DEM outperforms SRTM DEM in detecting vertical accuracy for the plane, and SRTM DEM is preferable than ASTER DEM for mountainous areas. The longitudinal profiles of dams (Kyzylsay and Tashtepa) of all DEMs are compared with the geodetic data of the design institute - UzGIP. The area and volume of the reservoir were determined using the digital model were compared with the data of the design institute - UzGIP performed using a geodetic tablet.
Land use by transport infrastructure in Tashkent City
Authors: Shipilova K , Radkevich M , Tsoy V , Shoergashova Sh , Vildanova L , Gapirov A 
Published: July 2020

Abstract
Achieving environmental sustainability of transport largely depends on the degree of use of urban land by transport infrastructure. The article studies the indicator “land use” in Tashkent to the target 2030. The following criteria were selected as assessment criteria: the area and degree of filling of public parking lots, the area of transport infrastructure enterprises, as well as the length of roads with two-sided landscaping. Evaluation of indicators was carried out using GIS, by processing satellite maps of Tashkent in the Quantum GIS program, as well as by monitoring online maps of the movement of automobile transport. It was revealed that the existing area of public parking is 33.4% of the required area, while the degree of use of existing parking is only 40-60%. Bilateral landscaping, have only 26.6% of roads. Trends in the development of the Tashkent transport system suggest mainly an increase in the number of private cars (an increase of 1.23 times by 2025), the pace of construction of parking lots and improvements in the road-street network are significantly behind (an increase in the area of parking lots by 1.06 times by 2025). In the current state of development, the stability of transport until 2030 according to the criterion of “land use” is not provided.
Matlab-model of a solar photovoltaic station integrated with a local electrical network
Authors: Sapaev I , Saitov E , Zoxidov N , Kamanov B 
Published: July 2020

Abstract
This article considers a model of a solar photovoltaic station (PVS) integrated with a local electrical network on the example of a 20 kW PVS installed in the building of the Tashkent State Technical University named after Islom Karimov. The Basic SIMULINK model of an equivalent PVS was used for analysis and comparison of PVS parameters. It is shown that the parameters for the mathematical model match the experimental parameters obtained under natural operating conditions at remarkable points. This model of PVS will serve as an experimental and laboratory stand in the teaching of students of the University for the subject “Renewable energy sources” (RES).
Designing of light traps, monitoring, and also pests control on its basis
Authors: Erkinov Z , Beknazarova Z , Turaeva G , Khudayarov M 
Published: July 2020

Abstract
The following article is given data about the construction of light-traps working on a semi-automatized or autonomic regime, and also about carrying out the monitoring of identification of the phase of pests’ development and control them with the given light-traps. Given light-trap was created on the basis of the latest achievements of science with the help of semiconducting materials. The device constructed from semi-conducted light-diodes, relay of twilight, and solar batteries assembled of silicium, which is concerned as a typical semiconducting material, and also from accumulating batteries. It is shown that the given method of conducting monitorings and pests’ control is ecologically healthy, hands down to use, and easy in transportation. The method allows getting objective information about kind and sex type, date and dynamics of flying out, egg-laying formation, and fertility of many kinds of agricultural pests and trapping pests with little waste of time and resources.
Optimization of power flow through facts in electrical networks
Authors: Khamidov Sh , Normuratov B , Pulatov B , Kilichov O 
Published: July 2020

AbstractA mathematical model is presented for optimizing power flows in an electric network with a flexible controlled alternating current power transmission device - FACTS. The range of questions on the problem of optimizing the power flow in electric networks with one of the FACTS devices, the SVC static power factor compensator, has been expanded and investigated. The Lagrange function for the SVC device is proposed, which serves as the basis for obtaining a linearized equation and determining the optimum of the objective function.The method and algorithm of the optimization problem in the electric power system containing devices of the FACTS technology have been synthesized. The mathematical model allows for flexible and reliable optimization of the electrical power system. Flexibility is explained by the universality of the model, and reliability is explained by the high convergence rate of the Newton method used.
Modeling of kinematics and kinetostatics of planetary-lever mechanism
Authors: Karimov R , Begimov N , Sadullaev Sh , Urinov B , Turajonov K , Ibodulloev Sh 
Published: July 2020

Abstract
The article provides analytical formulas for determining the kinematic parameters of a planetary-lever mechanism with one and two degrees of mobility. The obtained formulas were realized on a computer, in the program Math CAD 15. According to the results of calculations on a computer, regularities were established for the change in the kinematic parameters of the links of the mechanisms under consideration. The influence of the direction and magnitude of the angular velocity of the central wheel on the kinematic characteristics of the planetary-lever mechanism with two degrees of mobility has been determined. Formulas are created to determine the reaction in kinematic pairs of a planetary-lever mechanism with one degree of motility. Based on the calculation results and analysis provided, regularities of the reaction change in the kinematic pairs, as well as balancing moments in the carrier, were established during the basic geometric parameters of this mechanism were varied.
The machine for the preparation of the soil in sowing of plow crops under film
Authors: Ravshanov K , Fayzullaev K , Ismoilov I , Irgashev D , Mamatov S , Mardonov Sh 
Published: July 2020

Abstract
In the world much attention is paid to the development and application of machines that perform all technological processes of soil cultivation and preparation of soil for sowing crops in one pass on the field. The aim of the research is to substantiate the constructive scheme and mutual arrangement of the working elements of the machine for preparing the soil for sowing melon crops under the tunnel-type film. The authors proposed new technology for preparing the soil for sowing melon crops under the film of the tunnel type in one pass of the machine, including the surface loosening of the covered soil, milling-free loosening and formation of irrigation furrow along the axis of symmetry of the sowing zone, preparing the strip of soil for sowing melon crops under the film of the tunnel type. The design of the developed combined machine for the realization of the offered technology is resulted. The basic principles and methods of classical mechanics, mathematical analysis, and statistics were used in this study. It is established that the most optimal design scheme of the machine is considered to be a scheme with a sequential installation of a lancet leg, pairs of deep loosening machines, furrow cutters, and rotary working elements inclined to each other. It is theoretically proved that qualitative preparation of the field for sowing melons with minimum energy consumption is provided with the longitudinal distance between the deep loosened and the lancet leg of 40 cm, the transverse distance between the deep loosened and the support wheel of 10 cm, the longitudinal distance between the deep loosened and the furrow cutter of 50,6 cm, the longitudinal distance between the furrow cutter and the rotary working device of 123 cm.
Advance of spindle drum and frontality of active spindle surface
Authors: Rizaev A , Yuldashev A , Kuldoshev D , Abdillaev T , Ashurov N 
Published: July 2020

AbstractHarvesting machines of modern cotton pickers are equipped with spindle drums, making rotational movements against the direction of machine motion. To ensure the natural position of the bushes with bolls in the working area of the vertical spindle apparatus, the linear speeds of the spindle centers on the drums advance the speed of the machine. The aim of the paper is to develop a methodology for calculating the lead coefficient depending on the parameters of the drum, spindle, its activity, and frontal location, where the active surface of the spindle should be located opposite the cotton plant. Specific recommendations are given for calculating the operating modes of a cotton picker.
Drying agent spreading in stack of drying material
Authors: Umarov G , Buronov Sh , Amonov M , Mirzalieva E , Tulaganov B 
Published: July 2020

Abstract
This article analysis of drying agent’s spreading in ventilated drying of stem type agricultural crops and vegetable seeds, through which it aims to produce more and more high-quality products. The similar drying was not observed in different parts of the crops in ventilated drying, some parts of the drying product were dried out but some parts not dried well. The aims of the paper study this process. Therefore, products must be placed in the dryer with the thickness to have each point dry at the same time. Based on the practical experience of this criterion, the determination of loading thickness in drying was carried out theoretical analysis by using analytical dependencies. Theoretical analysis and analytical dependencies allow determining dimensions of the stack, layer thickness
Improvement of properties of oils used in hydraulic systems of road-construction equipment
Authors: Alimova Z , Kholikova N , Kholova S 
Published: July 2020

Abstract
This article proposes ways to improve the operational properties of hydraulic oils used in road construction equipment. Hydraulic oils with additives in the form of metal dithiophosphates or orthophosphoric esters can provide reduced wear of hydraulic elements.
We research samples of industrial oils MG – 30, and samples with the addition of zinc dithiophosphate additives DC – 40. The antiwear effect of such compounds occurs due to the adsorption of the metal surface with the formation of sufficiently strong compounds with the metal. In the presence of oxygen, the reactivity of sulfur compounds with respect to the metal decreases, but an increase in the antiwear properties of the compounds is observed mainly under moderate friction conditions.
The results of laboratory studies of MG-30 hydraulic oils with an additive based on zinc dithiophosphate DC – 7 and recommendations for their use are presented.
Device for forming longitudinal thresholds among rows of improved porosity
Authors: Murodov N , Abdualiev N , Murtazoev A 
Published: July 2020

Abstract
The article presents an improved technical tool and technology for the formation of longitudinal thresholds in the separation of the area between the processes that take place after the third cultivation in cotton-growing farms and between the processes that take place before the extraction of irrigation furrows into the Forties. To do this, the constructions of existing threshold forming devices are analyzed and a longitudinal threshold forming device is recommended among the rows of porous equipped with a condenser cathode, which has the most convenient constructive solution. When using this threshold generating device, there is an experimental study that allows to increase the productivity of work by 10-15 times without reducing labor costs by up to 7-8 times. As a result of the experimental research, the density of the floors formed after the application of the recommended device is 1195…The fact that it weighs 1298 κг/M3 is based on the existing parameters, saving water consumption on the account of reducing the leakage of water from one contour to another, as well as the yield from cotton fields to 50 c/ha. This innovation is reflected in the experiments that yield 25-30% higher after the formation of longitudinal upholstery among the rows of porous with the help of techniques and technology devices.
Experimental studies of deformation anisotropy of gravel soils
Authors: Bestuzheva A , Abduloev A 
Published: July 2020

Abstract
When gravel-pebble soil is laying and compacting into the dam body, particles are reoriented to form a layered body (transversely isotropic soil), in which not only the filtration but also the deformation properties are different in directions along and across the layering. To analyze the differences in the gravel-pebble soil deformations in correspondence with the particles’ orientation we have performed experimental researches on the river pebble gravel using odometer, vacuum triaxial compression machine, and a large scale triaxial apparatus. To obtain the deformation characteristics of the soil in different directions we’ve carried out experiments according to two schemes with gravel particles (fr. 10-60 mm) laid horizontally and vertically. More deformations occur in the cross-layerage axis of the soil rather than in the parallel direction (εy > εx), so for the soil in the dam body Ex > Ey. The experiments showed that for gravel-pebble soil the strain-induced anisotropy coefficient η is dependent on its loading conditions and changes in the range from 1 to 1.8. The change of anisotropy degree is bound with the main tension value σ1 with the increase in which the anisotropy decreases.
Chemical and mineralogical properties research of clay from the Republic of Karakalpakstan - as raw materials for Portland cement production
Authors: Orazimbetova G 
Published: July 2020

Abstract
In the Republic of Karakalpakstan, there are large reserves of unprocessed mineral building materials, which necessitate the development and targeted support of building materials manufacturing industries, which may become one of the engines of economic growth, further modernization, and diversification of the region’s industry. This article examined the chemical and mineralogical composition of technological samples of the clay component of the North Jamansay deposit. The results of determining the mineralogical composition of the averaged technological sample of clay from the Dzhamansay deposit are in good agreement with the data of chemical analysis. The heating curve of the averaged clay sample of the Dzhamansaysky deposit is marked by fourteen endothermic effects. The total weight reduction in the temperature range (60–900) °C according to the thermogravimetric curve is 9.53%. On the DTA curves of the clay of the Dzhamansayskoye deposit, endo effects associated with absorbed and ciolet water were identified, as well as endo effects corresponding to the gradual removal of constitutional water from the clay component, accompanied by destruction of the crystal lattice. Electron microscopic analysis of clay showed that the presence of particles of various sizes having a surface with rhombohedral protrusions. This can be seen both on the chips and on the surface of the particles, where rhombohedral protrusions characteristic of quartz are reflected. The chemical composition of the technological sample of the clay component of the North Jamansay field in terms of the content of regulated oxides (SiO2 = 62.64; Al2O3 = 17.54; MgO = 2.00; SO3 = 1.21; TiO2 = 0.46; P2O5 = 0, 25; R2O = 3.68)% meets the requirements of O’z DSt 2950: 2015 for the chemical composition of aluminosilicate (clay) raw materials used in the production of Portland cement clinker.
Physical modification of concrete mix and concrete
Authors: Khasanov B , Vatin N , Ismailova Z , Mirzaev T 
Published: July 2020

Abstract
Numerous studies have established that the physicomechanical properties of concrete, in addition to cement activity, type of aggregates, etc., are determined by the V/C value of the concrete mixture [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]. The dependence of the strength and water tightness of concrete on H/C follows from the physical nature of the formation of the concrete structure. Studying the process of cement hydration showed that cement, depending on the quality and duration of hardening, binds only 15 … 25% of the water of its mass [11, 12, 13]. During the first month, at least 20% of the water by weight of the cement is bound. At the same time, to give the concrete mixture plasticity, improve the conditions of binder hydration, a significantly larger amount of water is introduced, since at W/C = 0.20 the concrete mixture remains practically dry and it cannot be qualitatively laid, molded and compacted. Excess water, without entering into chemical reactions with cement, remains in concrete in the form of water pores and capillaries or evaporates, leaving air pores. Undoubtedly this is the main reason for the decrease in the strength and waterproofness of concrete.
Behavior of single pile and pile groups in consolidating clay
Authors: Znamenskiy V , Hegazy O , Sayed D 
Published: July 2020

Abstract
As the pile group is commonly in use but the effect of consolidation times on the distribution of negative skin friction and drag force along the shaft of each pile in pile groups is still not well defined and studied. This paper presents the three-dimensional (3D) numerical analysis to study the behavior of a single pile and piles group consist of 3x3 piles embedded in a consolidated clay. Three-dimensional numerical simulation is carried out using Abaqus, a finite element software. Single circular piles and 3×3 circular piles in rectangular piles group with a spacing of 2.5D has chosen, where D is the diameter of circular pile. Based on the analyses, it is found that the location of the neutral plane is significantly influenced by the consolidation times. Results of this study showed that the maximum negative skin friction at 90 % degree of consolidations developed along the shaft of corner, side, and central pile compared with a single pile are 69%, 61%, and 45%, respectively.
Joint work of a flat frame and pile foundations under dynamic impacts
Authors: Buzrukov Z , Khamrakulov A 
Published: July 2020

Abstract
In this paper, the basic data of theoretical and experimental studies of a flat frame on pile foundations are presented. Based on theoretical and experimental studies, methods for conducting experimental studies have been developed, the dynamic parameters of the system have been determined, the dynamic calculation scheme has been refined, and a method for calculating a flat frame with a pile foundation under dynamic loads has been developed. Calculation and comparative analysis of the results on the application of pile foundations following building standards are made and the advantage of the work of pile foundations under the condition of dynamic effects is established. Research results allow us to obtain the dynamic characteristics of a flat frame on pile foundations, necessary for subsequent calculations. An analysis of the modes of natural vibrations shows that for a system the 1st form of vibrations is apparently qualitatively different from the vibration form of a conventional single-mass system. To determine the degree of reliability of the developed methodology, the results of theoretical calculations carried out on the basis of the obtained formulas were compared with field tests for structures. The parameters used were adopted on the basis of theoretical calculations. Quantitatively, the discrepancy near the resonant frequency was about 15% in moving micron vs frequencies curves. The maximum amplitude of oscillations on this grillage very closely coincides with each other. With an increase in frequency in both cases, it leads to a decrease in the amplitude of oscillations of the grillage. The discrepancy between the theoretical and experimental values was about 16%.
The comparison of velaroidal shell structures of square plane load bearing properties
Authors: Tupikova E , Berdiev M 
Published: July 2020

Abstract
Velaroid surfaces is a class of analytical surfaces, formed by translating generatrix curves of variable curvature along the directrix curve of the same type, limited by plane contour lines. A new type of velaroidal shell –on the base of the catenary curve is introduced in this job, it’s surface equation obtained. The static structural analysis of the shells under equally distributed dead weight loading is conducted. Four types of structures of equal overall size and rising height were investigated: velaroidal shells on the base of catenary, parabola, ellipse, and sinusoid lines. The analysis is provided using the finite element method. The material has characteristics of reinforced concrete. The comparison revealed the peculiarities of each type of behavior under loading. The velaroidal shell with catenary generatrices demonstrates the most advantageous behavior under loading in the aspect of bending and membrane stresses ratio. This comparison is of interest for the potential introduction of such structures for roof elements.