bluuebunny/crossref_metadata_2025 huggingface dataset:
Glucose-oxygen biofuel cell based on laccase cathode and gold-modified carbon black anode: experimental research and mathematical modelling
Authors: Arkadeva I , Vasilenko V , Bogdanovskaya V , Sudarev G , Koltsova E
Published: January 2021

This research studies processes in membraneless mediatorless biofuel cell (BFC), including the processes of oxygen reduction at the cathode with a laccase-based catalyst and glucose oxidation at gold-modified carbon black (20Au/XC-72R) as an anode catalyst. The influence of the glucose quantity in the nutrient solution on the electrochemical activity of BFC was investigated. At pH=4.7 the highest power density of 2.6 µW/cm2was obtained for a solution containing 0.5 M of glucose. It was found that the concentration of glucose in the range of 0.2-0.5 M does not affect the electrochemical activity of immobilized laccase. The mathematical model of the studied BFC was based on the continuous stirred-tank reactor model, the electrochemical processes occurring on the electrodes were taken into account. The BFC’s output characteristics were calculated, profiles of the concentration of participants of electrode reactions on current density, the discharge curves, profiles of the power density dependence on current density at glucose concentration in the range of 0.1-1.5 M were obtained. The electrodes’ reactions rates dependences on the current density of BFC confirm that the cathodic reaction is limiting. Optimization of the BFC operation modes showed that the optimal glucose content at the nutrition solution is 0.546 M.
A review on Hybrid Electric Vehicle and simulation on Hybrid Electric Vehicle Drivetrain
Authors: Bapodra Yagnesh , Rajamanickam Udayakumar
Published: January 2021

This paper discusses about the Hybrid Electric Vehicle (HEV) and the simulation on the Parallel Hybrid Electric Vehicle Drivetrain. The concept and the classification of the HEV is discussed here and the simulation and analysis of a drivetrain for Parallel Electric Hybrid Engine (PHEV) was formulated on MATLAB Simulink. The methodology of simulation was to accelerate or decelerate the vehicle independently with the electric motor with engine running at constant speed. And the parameters such as electric motor and engine power were compared and observed. And research on CO2 emission and fuel consumption was made between the PHEV and Conventional Vehicle (ICE Vehicle). And the conclusion was made according to the research and the simulation that the development of HEV will have a great potential in fuel economy improvement.
Simulation and Analysis of glare effect of two lane tunnel lighting under symmetrical lighting arrangement
Authors: Jianyou Yu , shuya Sun , xiaocong Wang , Zhizhong Liu , Jianbo Wu , Yanxin Chen , Shengshen Ge
Published: January 2021

Glare seriously affects the quality of tunnel lighting, and also has a negative impact on drivers’ visual recognition in the tunnel. By introducing the calculation method of glare influence level G and relative threshold increment TI, the article uses DIAlux evo lighting simulation analysis software to simulate and analyze the tunnel lighting glare of different installation spacing and angle combinations under the condition of Symmetrical lighting on both sides in the tunnel. The influence range of glare produced by different installation spacing and angle combinations under symmetrical lighting is obtained. The research results show that: in the symmetrical lighting mode on both sides of the tunnel, when the angle between the driver’s sight line and the incident direction of the tunnel lighting is less than 82.38°, the lamps will produce glare to the driver. When the glare influence level of symmetrical bat-wing tunnel lamp is between 1 and 3 at any installation distance and angle under the symmetrical arrangement of lights on both sides, it is a serious glare effect.
Extremely Low Cycle Fatigue Failure Behavior of Box-column to I-beam Welded Joints
Authors: Huang Lizhen , Qu Weilian , Wu Cai
Published: January 2021

In this paper, cyclic loading tests are carried out to study the extremely-low-cycle fatigue (ELCF) failure behavior of the beam-to-column welded joints of steel structures subjected to severe seismic excitation. Firstly, the fatigue crack evolution and local strain of the weld zone obtained from experiments are adopted to investigate ELCF failure behavior for steel structures. In these experiments, three large scale specimens of box-column to I-beam connection are controlled by different cycle displacement ranges greater than the yield displacement. Secondly, the crack initiation and propagation law as well as the damage and deterioration mechanism are examined; then, the preliminary criterion for crack initiation for the box-column joint is proposed. Finally, failure characteristics and strain distribution of the box-column joint are analyzed. This study shows that the ELCF failure of the box-column to the I-beam joint is multiaxial and nonproportional. Based on the crack initiation and propagation along the thickness direction of the beam flange, the crack macro-penetration mode can be divided into two categories, i.e., standard failure mode and mixed failure mode. Moreover, load drop, change rate of load drop, and loading amplitude are key factors of the damage mechanism.
Energy saving potential analysis of the application of Cooling tower cooling technology in Guiyang
Authors: Su Ying , Hu Cheng , Li Lei , Mao Ruiyong
Published: January 2021

We conducted research on the development of cooling tower cooling technology and the trend of wet bulb temperature in Guiyang throughout the year. According to the results, we found that the cumulative number of hours in which the wet bulb temperature of Guiyang was ≤14°C totaled 4327 hours, which accounted for 49.39% of the total. On the one hand, in winter, when the wet bulb temperature is 14°C as the switching temperature, the theoretical cooling hours in winter is 2130 hours. On the other hand, in spring and autumn, the theoretical hours of indirect cooling tower “free” cooling totaled 1904 hours. At the same time, it is worth mentioning that in winter and transitional seasons, the theoretical cooling hours account for 94% of the total free cooling hours available for cooling towers throughout the year. Through further analysis, we believe that the application of this technology in Guiyang has good energy-saving potential and application value. It should be noted that in actual engineering applications, the utilization characteristics of natural cold sources also need to be considered. At the same time, we have to combine the terminal form of the air conditioner and the characteristics of the cooling load to give full play to the energy-saving potential of cooling tower cooling technology.
Transient and harmonic analyses of South Memnon Colossus including soil-structure interaction
Authors: Yu Taize , Chen Xiaokun , Liu Siyu , Ling Yijie
Published: January 2021

In this work, a 3D model of an ancient statue -- the South Memnon Colossus, was built, and its dynamic response to sinusoidal earthquake motion was investigated. In the transient analysis, parametric studies were conducted to better understand the impact of ground motion characteristics (frequency, amplitude, and direction) on the structure’s seismic response. The comparison was made of the dynamic responses with and without soil-structure interaction effects. The analyses were conducted in MSUP (linear) mode of a commercial finite element code ANSYS. The solution was obtained in the frequency domain and showed increasing deformation as the load frequency approaches the natural frequency of the structure (resonance).
Research on probabilistic diagnosis-based structural damage identification using two-phase fusion of multi-source information
Authors: Zhuo Debing , Cao Hui , Liu Aili
Published: January 2021

Several de-noising techniques have been proposed previously. However, in structural damage identification, it is still difficult to effectively eliminate the influence of noise by using any de-noising technique due to the complexity of environmental noise. This difficulty leads to the failure of some damage identification indices when used in practical applications, despite their high sensitivity to damage in simulation analyses. This paper proposes a probabilistic diagnosis-based method involving the fusion of two-phase multi-source information. First, local decision results of structural damage were obtained by using the improved element damage variable and the element stiffness reduction factor. Then, the Dempster-Shafer(D-S) evidence theory was used to fuse the local decision results to obtain the final decision results. By performing a simulation analysis and dynamic tests of a reinforced concrete beam and steel beam, it was confirmed that the proposed procedure demonstrated good stability and noise resistance.
Research on Emergency Escape Support System for Operation Risk of Highway Extra-long Tunnel
Authors: Zhang Zhigang , Qu Shangwen , Yang Yang , Zhang Guoxiang , Zhang Xin , Hou Lingchao , Jiang Li
Published: January 2021

The special driving environment of highway extra-long tunnels causes high operational risks and difficult escape. The establishment of a sound emergency escape support system is essential for drivers to escape safely in risky accidents. Based on the factors such as the type and severity of tunnel operation risks, this paper studies and puts forward the level of extra-long tunnel operation risk management and the requirements for safe emergency escape of relevant personnel under different levels, and establishes and improves the composition of the extra-long tunnel emergency support system and the function, location and spacing of each facility in the subsystems. Considering the condition of extra-long tunnels, the research conclusions provide a scientific basis for emergency escape management and establishment technology, and proposes a safer support system for emergency escapes.
Fracture of a gas pipeline manufactured by high frequency current welding
Authors: Alexeev A A , Syromyatnikova A S , Bolshakov A M , Ivanov A R
Published: January 2021

Fracture of an underground gas main with a diameter of 530 mm during the production of pneumatic tests along a factory longitudinal welded joint made by contact welding using high-frequency currents, is considered. Fracture research was carried out by analysis of the project and technical documentation of the object, visual and measuring control of the object, ultrasonic measurement of pipe wall thickness, fractographic, metallographic and chemical analyses, measurements of hardness and microhardness of pipe metal. It was established that fracture of the gas pipeline occurred as a result of the opening of one pipe along the entire length of the factory-made longitudinal welded joint during the propagation of cracks in the welded joint and the subsequent propagation of the main crack in both directions to adjacent pipes; the centers of fracture were numerous surface crack-like defects of the welded joint. It is shown that a fracture was caused by a violation of the welding technology of a longitudinal welded joint, a violation of heat treatment, an unacceptable thinning of the pipe wall in the weld zone.
The effect of process parameters of gas-dynamic spray on generation of brass-type coating structure
Authors: Arkhipov V E , Moskvitin G V , Pugachev M S
Published: January 2021

The study results have shown the effect of coating temperature and contact ratio on generation of phase structure of the coating based on the mixture of Cu and Zn particles and Al2O3 applied by cold gas-dynamic spray method. The x-ray diffraction and micro-spectral analyses have shown the presence of copper and zinc in the structure and generation of electronic compound based on CuZn3 (e – phase) and Cu5Zn (γ – phase), which is preconditioned by copper diffusion into zinc. The mass fraction of intermetallic compositions in the coating structure depends on the coating temperature and contact ratio, it reaches 12% and 33%. The analysis of surface processing by solid and plastic particles flow has shown the effect of copper particles deformation on diffusion rate.
The development of models of risk assessment complex transport systems
Authors: Makhutov N A , Panov A N , Yudina O N
Published: January 2021

The article deals with the actual problem of risk optimization for complex transport systems. Optimization models for risk aspects are proposed and developed: “probability-damage”; “quality-price”; “variation-damage”; acceptability of the measurement system; degradation monitoring.
Development of multilevel models for assessment of risk of train derailment
Authors: Reznikov D O
Published: January 2021

The paper presents a multilevel model for assessing risk of train derailment. The model is based on the toolkit of Bayesian nets and allows accounting for the influence of human and organizational factors as well as factors of safety regulation regimes on the occurrence of stochastic events that compile various scenarios of railroad accidents.
Damaged zone thickness estimation method for machined FRP composite specimens
Authors: Vlasov D D , Tatus N A , Polilov A N , Akhmedshin E Kh
Published: January 2021

The results of the experimental study of machining effect on the fiberglass specimens’ tensile strength realization are presented. According to the data obtained, the size of the damaged zone, which does not carry applied loads and reduces the actual net cross-section of the specimen, has been estimated.
The role of aluminum and iron hydroxides in the formation of concrete properties
Authors: Ovcharenko G , Ibe E
Published: January 2021

Aluminum and iron hydroxides, formed in the stone during the hydration of cement with the addition of special slags, significantly improve the properties of concrete. The addition of low-basic calcium aluminates CA2 and CA6 in the form of high-alumina slag, which releases a large amount of Al(OH)3 during hydration, increases the strength, density, water resistance, frost and corrosion resistance of hydraulic concrete. A compressed mixture of concrete scrap and high-alumina slag based on low-basic aluminates makes it possible to obtain durable and frost-resistant materials and pavement structures. A special nickel slag of increased basicity in a mixture with Portland cement ensures the formation of ferric hydroxide during hydration. Concrete on such Portland slag cement shows frost resistance for more than 500 cycles without special measures.
Calculation of elastic-creeping characteristics of a beam made of a layered composite material
Authors: Bobyleva T N , Shamaev A S
Published: January 2021

Multilayer composite materials are often used in building structures. The direct calculation of layered structures requires large expenditures of computer time. Therefore, the homogenization method is used. This method reduces the problem of a layered material with isotropic layers to the problem of a homogeneous transversely isotropic medium. The material considered in the article is also elastic-creeping. In the equations of state of such a material, terms of the convolution type with difference creep (relaxation) kernels are added to the terms of the usual theory of elasticity. The creep (relaxation) kernels are represented by decreasing exponential functions depending on two parameters. This problem becomes a problem of the theory of elasticity with a parameter after applying the Laplace transform in time to it. The inverse Laplace transform can be done in a computer algebra package, for example, Wolfram Mathematica, Wolfram-alpha. The obtained characteristics of the material are used to solve the problem of a layered elastic-creeping beam with hinge support. Formulas are given for determining displacements in the case of layers parallel to the beam axis.
Using the method of vertical reinforcement for design of the soil base
Authors: Stepanischev Konstantin , Sidorov Vitalii
Published: January 2021

In this paper, the method of vertical reinforcement of the base with reinforced concrete elements is considered, applied at a real site in Ekaterinburg. The construction site is characterized by difficult engineering and geological conditions due to the uneven occurrence of eluvial and rocky soils of variable thickness, as well as the presence of specific soils within the soil massif. The imperfection of the normative documentation, based on the lack of knowledge of this method, makes it difficult to design these foundations under load. Frequent comparison with structures typical for traditional pile foundations leads to problems when justifying this method in local authorities of state expertise and sometimes does not take into account the uniqueness and economic efficiency of this topic. The advantages and disadvantages of this method are highlighted when using it in the design of a real object.
Telemetry in the life support system of an intelligent building
Authors: Mokrova Natalia , Alyoshintsev Andrey , Sak Alexander
Published: January 2021

The automated system of control and management of life cycle of an intelligent building and, in general, of the Smart City requires high-quality supervision, control and preventive maintenance to handle water supply networks, delineation of operating balance and responsibility for engineering networks functioning and structures between suppliers and consumers, ensuring water analysis.

This article discusses the advantages of a module that sends data to telecontrol in real time and allows to solve problems such as: continuous and comprehensive monitoring of the state of a remote DWI (Drinking Water Intake) object; remote control of the object; remote control of the actions of the staff; automatically preventing personnel from incorrect actions; increasing the level of organization of energy accounting, efficiency and reliability of obtaining information; improving safety, production culture and improving working conditions; obtaining detailed information about the parameters of the power grid, the electrical equipment operation and the implementation of dispatching control in real time; optimization of technological modes of operation.

The study can help reduce the number of accidents at facilities and improve work efficiency as well as solve the issues of work by providing the equipment with new devices, such as MCU series controllers.
Construction of mathematical model for the controlled dynamics of connected bodies system in robotics
Authors: Polyanina Anna
Published: January 2021

Differential-algebraic equations for describing the motion of connected bodies sys-tem are considered. The dynamic model includes geometric and nonholonomic connections. The connections equations contain second-order derivatives of the system coordinates. The in-fluence of connections by the system is taken into account using Lagrange multipliers. Pro-posed equations of controlled motion can be used in the development of algorithms for model-ing the motion of mechanical systems, in particular, in the construction of control systems for cyclic motions in robotics. To construction, solve a mathematical model using software pack-ages, it is necessary to obtain the equations of motion for all components of connected bodies system. The presence of many numbers of walking robots mobility degrees makes the task of their creation and control more difficult. The synthesis of control systems for such devices is reduced to stabilizing the motion of the robot body. Algorithm for setting the trajectory de-pends on the relative motion of a point on the body from the point of the foot. The body makes uniform rectilinear motion while the foot makes periodic motions.
Methodology for calculating previously unaccounted for heat losses of internal hot water supply systems
Authors: Hurgin Roman , Nosorev Evgeniy
Published: January 2021

For a long time, design engineers calculated heat losses according to the method proposed in SNiP 2.04.01-85*, i.e by multiplying the specific value of heat losses per unit length of the pipeline. While this methodology is good enough for simple calculations, it lacks in preciseness, which in turn can lead to an overengineering of the hot water system. In 2017, SP 30.13330.2016 was introduced, in which the calculation of heat loss by pipelines of the hot water system from SNiP was changed to include previously unaccounted for heat losses that were not calculated. Now this methodology almost fully reflects the physical processes of heat transfer, considers the corresponding design parameters, and delivers more precise calculations, than SNiP methodology, which in turn allows to account for precise numbers of heat loss in hot water system. Detailed analysis of formulas and their components will provide better understanding of processes which affect heat losses in hot water systems.
The assessment of technical -economic efficiency of Sequencing Batch Reactors in municipal wastewater treatment in developing countries
Authors: Quan Tran Ha , Gogina Elena
Published: January 2021

The Sequencing Batch Reactors (SBR) is a variation of activated sludge and has been wide applied in wastewater treatment since 1920s. The advantages of this technology are not only the high performance in low or varying flow patterns but also present worth cost for a long time. Therefore, the article evaluates the technical -economic efficiency of this technology in municipal wastewater treatment from combined sewerage system. Based on building and operation pilot SBR with process Nitrification/Denitrification and bio-film in municipal wastewater treatment plan for 1 months, the technical -economic efficiency has been determinates. Firstly, the efficiency removal pollutants is more stable and the quality of pilot’s effluence achieved Russian Standard about treated water. After that, the environmental damage has been decreased for 8 – 11 time, especially damage from nitrogen ammonia and nitrate. At least, the calculation from economic factors of SBR has been showed that the cost of treating 1 m3 wastewater than 0.5 USD when optimized this technology by process Nitrification/Denitrification and bio-film.
Investigation of scaling mechanism on reverse osmosis membranes using «fluorescent» antiscalant
Authors: Golovesov V A , Pervov A G , Smirnov A D
Published: January 2021

Scaling of sparingly soluble salts could be recognized as a main factor that limits wide application of reverse osmosis (RO) membrane facilities in drinking water production and industrial water recycling. The report demonstrates a new approach to evaluate scaling rates and antiscalant behavior in commercial membrane spiral wound modules through the use of the fluorescence-tagged antiscalants and laser scanning confocal microscope (LSM) observations. Throughout the conducted study the “visualization” of scale inhibitors behavior appeared to be a very promising and universal tool for their activity understanding. Examination of membrane surface and calcite crystals in autopsied membrane modules demonstrated new unexpected results: antiscalant adsorbed either on membrane surface or on crystal surface. In the presence of calcium ions during ground water treatment antiscalant was adsorbed only on crystal surface and sorption on membrane was not detected. Fluorescence was more intensive on the surface and on the outer edges of crystal surface than inside crystal. To investigate antiscalant adsorption to membrane surface, experiments with distilled water containing antiscalant were performed. Intensive sorption of fluorescent inhibitor molecules to membrane was observed.
Strategies ensuring the Stability of Natural and Urbanized Biotopes in hybrid multifunctional objects
Authors: Zaykova Elena
Published: January 2021

The typology and strategies for integrating hybrid multifunctional objects into the urban fabric will be presented in the article. The dominant feature of the third group is the hybridization of functions between the building and the environment based on blue – green technologies for the sustainable development of urban areas and urban management. Three groups of hybrid objects have a compact and dispersed influence in different parts of the city. In the process of urban territory restructuring, the question arises of preserving and maintaining a natural or urbanized biotope, either by using natural components or by imitating natural communities using new technologies. Thus, different types of phytocenoses are formed in hybrid objects, which need to be preserved and adapted to the new socio-cultural and economic scenario of urban life. Artificial forms of urban nature require new strategies for the development of territories at different urban planning levels and in different parts of the city. Therefore, the topic of the article is of interest to a wide range of specialists.
Analysis of world and domestic experience in the use of XML schemas in the implementation of information interaction during maintaining the information model of a capital construction object
Authors: Chelyshkov Pavel , Volkov S A , Babushkin E S
Published: January 2021

The lack of integration solutions for transferring data according to the information model of the capital construction object or certain parts of the information model between different systems (for example, from the customer to the expertise, from the contractor to the State information system for the provision of urban planning activities (GISOGD) or other state information systems) leads to the loss of data and important information stored in the information model, which accounts for reproduce or transmit in native format without the possibility of data processing by the information system. The purpose of this article is to analyze the world and domestic experience of using XML schemes for organizing the processes of transferring and storing structured data in information systems (including government ones) and software with a reasonable selection of best practices.
Evaluation of the deformability of balcony plates of monolithic residential buildings
Authors: Malakhova Anna , Malakhov Dmitry
Published: January 2021

The calculation and design solutions of balconies of modern monolithic residential buildings are considered. Such balconies are part of a monolithic floor slab, which relies on internal supporting vertical structures. They have a larger extension, and when using brick walls to fence balconies -and more loading. The experience of operating monolithic residential buildings with balconies with their removal of 1.2 … 2.5 m and a brick balcony railing with a two-chamber stained-glass window showed the possibility of increased deformations of the balcony cantilever sections of the floor slabs of such buildings. If for such balconies the maximum deflection provided by the project for the balcony cantilever sections of the slab will be close to the maximum permissible values, then deviations from the design that were allowed during the construction of the building (reducing the class of concrete versus design, changing the location of the working reinforcement of the slab during concreting) can lead to increased deflection of balconies. Computer modeling allows you to accurately reflect the real work of the structure, and performing calculations in a nonlinear setting -to obtain an adequate deflection of the console balcony slab. The main approaches to modeling the design scheme of a flat floor slab with a balcony part are considered for determining plate deformations taking into account non-linear deformation of materials, as well as taking into account plate reinforcement.
The problem of mathematical modeling of a vibration protected rod under kinematic exitations
Authors: Mirsaidov Mirziyod , Dusmatov Olimjon , Khodjabekov Muradjon
Published: January 2021

In this paper, we consider the problem of mathematical modeling of nonlinear vibrations of a rod with distributed parameters and elastic-dissipative characteristics of the hysteresis type, and also having a liquid section dynamic absorber under kinematic excitations. The method of obtaining the differential equations of motion of the system protected from vibrations under consideration in the work using the structural method -the method of bond graph. An expression is obtained for the transfer function of a vibration-protective system for analyzing the dynamics and stability of the system and evaluating the effectiveness of a dynamic absorber.
Geometrically nonlinear analysis of a flexible wire (chain)
Authors: Suvorov Alexander
Published: January 2021

In this work the deformation analysis of a flexible cable is considered in detail. Nonlinear finite element analysis is used for solving the problem. In deriving the final form of equations, geometrically nonlinear analysis is used and validity of simple Hooke’s law is assumed. The resulting nonlinear algebraic equations are solved by using simple iteration method. Numerical examples are considered.
Vibrations of multilayer composite viscoelastic curved pipe under internal pressure
Authors: Safarov Ismoil , Teshaev Muhsin , Yarashev J A
Published: January 2021

The paper presents a mathematical statement and the methods to solve the problem of natural vibrations of thin-walled multilayer composite viscoelastic curved pipes under internal pressure. A brief overview of well-known publications devoted to this problem is given. The stress state and flexibility of the pipes are investigated for two types of boundary conditions, taking into account internal pressure and viscoelastic properties of the material and geometrical and physical parameters of the pipe. The paper provides the results of numerical analysis of the spectra of the lower complex eigenfrequencies of the pipe depending on internal pressure, geometrical, structural parameters, rheological properties and boundary conditions. Ten lower eigenfrequencies were found and the corresponding vibration modes constructed. The paper presents a comparison of solution results with known solutions and experimental results.
Mathematical modelling in tasks of predicting the operational reliability of gas networks facilities
Authors: Orlov Viktor , Detina Elena , Kovalchuk Oleg
Published: January 2021

This article offers a technology for studying accidents at gas networks facilities using mathematical models. In the constructed mathematical models, time series were research to obtain a forecast of accidents for the considered period of time. Forecasting was carried out using the method of variance analysis, which allows to obtain a qualitative version of the forecast. The confidence intervals of the forecast values obtained are they agree well with statistical data on emergency situations on gas pipelines. The developed methodology helps to increase the effectiveness of measures aimed at reducing negative crash factors and improving the operational reliability of gas networks facilities.
Research of the bearing capacity of a augered pile with expansion along the pile body
Authors: Chunyuk D Y , Van Hung Tran
Published: January 2021

Augered piles are used to reinforce the soil and connect to the foundation to ensure the sustainability of the project. This is an advanced method that can support large structures on soft ground. Augered piles are one of the most widely used structural solutions for foundations used by designers for high-rise buildings, in projects with heavy loads, bridge construction and for buildings located on soft soils. Due to their hability to withstand heavy loads without affecting neighboring buildings when constructing foundations, bored pile foundations are increasingly being used in civil, industrial, and bridge and road projects in Vietnam. Geotechnical conditions in Vietnam are mainly represented by soft soils, so many engineers are working to optimize the section of the augered pile to increase their bearing capacity. However, studies of augered piles capable of expanding the body of the pile to increase the bearing capacity along the side surface and reduce the volume of concrete have not been carried out. Investigation of the type of augered pile with the above characteristics is one of the most important tasks. The load on a augered pile, with widening along the body of the pile, increased from 15.4% to 20.8% compared to a conventional augered pile with the same total volume, and the same precipitation. The load on a augered pile with widening along the body of the pile increases from 15.4% to 20.8% compared to a conventional augered pile with the same volume of concrete. For augered piles with expansion along the body of a pile with the same outer diameter (D1200mm), as compared to conventional augered piles, the load decreased by 241 (tons), equal to 7.94%, but the volume of concrete decreased by 19.8 m3, which is equivalent to 37, 4%.
Solution of the problem of rotation of a homogeneous disk by the variational method, the apparatus of vector analysis and the finite element method
Authors: Saiyan Sergey , Modestov Konstantin
Published: January 2021

This work considers two global approaches to obtaining solutions to problems in mechanics: analytical and numerical, their division into various methods, allowing a more flexible approach to the choice of optimal methods for obtaining solutions to problems of continuum mechanics. Analyzed the effectiveness of various analytical methods for obtaining resolving continuum mechanics. In particular, the derivation of differential equations of equilibrium from the condition of minimality of the potential energy of elastic deformation of a solid, as well as the mathematical apparatus of vector analysis of classical field theory. In addition to the analytical solution, a numerical solution of this problem was presented by the finite element method, performed in the ANSYS Mechanical APDL software package, followed by verification of the obtained simulation results with the results of the analytical solution.
Optimization of bearing capital of structural roof slab
Authors: Vasilkin Andrey
Published: January 2021

The problem of exploring the optimum alternative of bearing capital of structural roof slab design solution is set and worked out in the article. As a method of searching for the optimum alternative, the parametric optimization method is used. Previously, a number of examples illustrate the application of this method. Then one variable parameter is chosen so that its changing provides a graph of objective function behavior, which in turn provides an optimal constructive solution according to the assumed optimality criterion. Constraints of the problem are strength and sustainability regulatory requirements and also a number of design parameters. Metal consumption was assumed as an optimality criterion. The work presents efficiency and relevance of optimization procedures while searching for design solutions at the early (conceptual) stage of design, which provide for an engineer the necessary information to choose reasonable design solutions based on options analysis.
The mutual influence approach during the resource allocation process in construction projects
Authors: Dayoub Nbras , Fakhratov Muhammet
Published: January 2021

Project scheduling is one of the most important stages of construction project planning, which can be divided into several tasks. Resource allocation is one of them. Resource allocation plays an important role in defining and forming the appropriate implementation plan that achieves the best cost and quality within the shortest possible period. This paper aims to provide a practical approach that helps the project planner in performing the resource allocation process in the manner that achieves the most benefit and effectiveness based on actual values, the use of databases and a mathematical analytical model. The results showed that the proposed model can provide significant benefit in the process of resource allocation and risk management, and that it is flexible to support decisions during decision-making processes.
Methodical approach to assessing the energy efficiency class of an industrial facility based on an expert opinion
Authors: Verstina Natalia , Meshcheryakova Tatiana , Shchepkina Natalia
Published: January 2021

The article examines an expert survey as the effective way to obtain information which is necessary to form a unified statistical information base of industrial facilities in terms of their energy efficiency. The conceptual model for developing a methodology for the expert survey of leading Russian and world experts in the field of energy efficiency and energy saving is presented. The model reflects the main elements which should be taken into account when conducting it. The toolkit for conducting the survey is proposed, which determines the basis for the classification of industrial facilities according to their level of energy efficiency. The analysis of expert opinions will make it possible to draw unambiguous conclusions to the overall opinion issues of the study and reach a consensus on its key problems.

Funding: The reported study was funded by RFBR, project number 20-010-00754
Asymptotics of inverse filtration problem in porous media
Authors: Kuzmina Liudmila , Osipov Yuri , Tzariova Victoria
Published: January 2021

Filtration problems arise in the design of tunnels and underground structures. A one-dimensional filtration model of a monodisperse suspension in a homogeneous porous medium is considered. For a general nonlinear filtration function, an asymptotic solution is constructed behind the concentrations front of suspended and retained particles. It is shown that the asymptotics is close to the numerical solution. Comparison of the asymptotics with the suspended particles concentration at the outlet of the porous medium allows solving the inverse filtration problem on finding the nonlinear filtration function. The proposed method allows to obtain the filtration function based on the results of standard laboratory experiments.
The influence of experimental studies on the stability of hydraulic structures
Authors: Aldungarova Aliya , Sarabekova Ulbossyn , Zhusupbekov Askar , Tanaka Tadatsugu , Tanzharikov Panabek
Published: January 2021

The article shows the main causes of accidents dams, including the effect influence of the undermining of territories. The aim of this work was to evaluate the possibility the formations in the model of the dams a cracks with certain areas of their distribution, as well as the degree of influence of reinforcement on their overall stability. Failure analysis shows that the reliability of these types of structures is different and depends on the uptime of individual subsystems. For soil dams, the largest number of failures is associated with filtration problems in the body and foundation of the dam during emergency floods. The decrease in stability and the increase in the development of crack formation during deformation of the soil base is greater, the greater the horizontal and vertical deformation of the soil. The effect of the reinforcing effect during stretching of the soil base, i.e. reinforcing the soil dam with geotextiles significantly affects the increase in stability and the decrease in the development of cracking during deformation of the soil base.
Hydrodynamic effects on the flow elements of the downstream devices in the presence of cavitation
Authors: Obidov Bakhtiyor , Vokhidov Oybek , Tadjieva Durdona , Saidkhodjaeva Dilsora , Kurbanova Umida , Isakov Alisher
Published: January 2021

The use of “erosion-free” energy absorbers operating during cavitation without the formation of cavitation erosion extends the use of energy absorbers and diffusers at high flow rates, removing or reducing cavitation restrictions. Considering that energy absorbers are effective means of preventing dangerous malfunctioning currents in the downstream, they make it possible to increase the water level and reduce the cost of fastening the downstream. Give the opportunity to expand the scope of their application should be taken into account when designing. Dampers of this type were used at the spillways of the Shamkhor and Artyom waterworks.
Estimation of the forecast of pump ready rate for reclamation systems
Authors: Glovatsky Oleg , Ergashev Rustam , Nasirova Naira , Kholbutaev Boybek , Khusanbayeva Khusnora
Published: January 2021

The aim of the authors’ research is to improve the hydraulic conditions for supplying the flow to the impeller and to reduce the cavitation wear of the pump working bodies. This goal is achieved by the fact that the device for supplying liquid at the inlet to the pump contains guide elements in the form of flat plates mounted on the axis of the suction pipe. With further modernization, the pumped liquid was stabilized after the impeller, with the elimination of vortex flows along the entire flow path of the pump due to new elements in the pump chamber. The problem is solved by the design of a straightening blade with a free cross-sectional area of the wall channel less than the inner channel. The research methods include the conduct of field and laboratory studies using modern technical means of observation. Long-term experimental work carried out at large pumping stations investigates interconnected systems of connecting structures and pumps. The stability function is determined as a result of taking into account a number of factors: the external environment, technological properties of systems and operational requirements. The change in the critical, from the point of view of the emergence of cavitation, the value of the pump supply from different densities of the pumped liquids was established as a result of bench tests. In the experiments, the cavitation erosion of the growth was compared with analogs in the average 90-100 times. The ratio of the performance of the surface tension force to the density for mercury and water at a temperature of 15° C turned out to be equal to 91. As a result of the development of a new design together with Joint-Stock Company SUVMASH and the method of calculating the working parts of the pump with a minimum wear rate of the pump with a minimum wear rate of 5%.
Current use of water intake structures of reservoirs
Authors: Urishev Adham
Published: January 2021

The detailed study of the flow of water in this area is of great importance in designing the sub-surfaces of the drainage and drainage structures of hydraulic structures. In particular, the complex processes associated with the flow of water in the lower and lower reaches of reservoirs of low and medium size play an important role in the choice of appearance, constructive elements and their shape, size and location.
Results of a numerical study of currents in the vicinity of a damless water intake
Authors: Krutov Anatoly , Norkulov Bekhzod , Uljaev Farokhiddin , Jamalov Farkhod
Published: January 2021

The problem of sustainable water intake in the conditions of significant fluctuations of flow rates and water level is significantly exacerbated by erosion of river beds. A typical example of such conditions is the damless water intake into the Karshi Main Canal (KMC) where the main flow of the Amudarya river continuously moves along a wide floodplain, changing the direction of currents. As a result, it is very difficult to withdraw the required volume of water from the river to the canal especially during dry years due to the high instability of currents at the entrance to the canal.

Within the framework of the performed numerical studies, the conditions of flow spreading (vectors of depth-average velocities) were studied in the specific time intervals and crossings in the water intake area. The results of the study confirmed that without special engineering measures it is practically impossible to assure stable water diversion into the canal. As a preliminary solution of the problem, it was proposed to make a trench along the right bank in the area of water intake into the canal.
Hydraulic modes of damless water intake
Authors: Uralov Bakhtiyor , Rakhmatov Norkobul , Khidirov Sanatjon , Safarov Gayrat , Uljaev Farokhiddin , Raimova Ikboloy
Published: January 2021

The article is devoted to the study of the influence of the damless water intake on the hydraulic and alluvial regime of the river, the channel of which passes through easily washed out soils. The analysis of the dynamics of the river bed morphometry and hydraulic elements of the flow in the area of the damless water intake is carried out. As a result of the analysis of the data of long-term field studies and hydrometric measurements at the closest section to the damless water intake and in the area of the damless water intake of the Amudarya River, functional relationships were established between the morphometric parameters of the channel and the hydraulic parameters of the flow. The dynamics of the Shezi coefficient, hydraulic resistance, and the channel roughness coefficient in connection with the hydrodynamic characteristic of the flow are established.
The height of the pumping unit suction pipe inlet relative to the riverbed bottom
Authors: Ikramov Nazir , Majidov Takhir , Kan Eduard , Akhunov Doniyor
Published: January 2021

Currently, 78% of all irrigated land in Uzbekistan is provided with water by pumping stations and installations. The water sources of most pumping stations are rivers and irrigation channels that transport a large amount of bottom and suspended sediments. Due to the lack of consideration of bottom sediments moving in the form of ridges, when installing the pumping units suction pipeline, during their operation, these bottom pumps flow from the water intake source in the interior of the units. As a result, intensive waterjet wear of the flow part and the impeller of the pumps occurs. This leads to an intensive reduction in the main parameters of the pumps, as well as reduces their repair period. Currently, this is one of the major problems of pumping stations that take water from the Zarafshan river, as well as those operating on the Karshi, Amu-Bukhara, Amu-Zang and Jizzakh main channels. Laboratory studies were carried out on the experimental installation to determine the height of ridges with different granulometric composition of bottom sediments. As a result, a formula was obtained for determining the height of the ridge, taking into account the heterogeneity of ridge forms. Based on the obtained formula, a method for setting the height of the pumping unit suction pipe inlet relative to the riverbed bottom is recommended. The application of the proposed method does not allow bottom sediments to enter the inner part of the pumps, as a result of which their intensive abrasive wear decreases, the inter-repair period increases, while maintaining its main parameters for a long time.
Numerical method for solving the problem of the gas-dynamic state of a main gas pipeline section relief of a variable cross-sectional area
Authors: Bazarov Orifjan , Khujaev Ismatulla , Mamadaliev Khusniddin , Khodjayev Shukhrat
Published: January 2021

The paper proposes a numerical method for solving the problem of the gas-dynamic state of a main gas pipeline linear section, which is characterized by a path change in the diameter and leveling height of the pipeline axis. The quasi-one-dimensional equations of gas pipeline transport are derived with account for the local and convective components of the inertia force, the quadratic law of resistance and the force of gravity at a variable cross-sectional area of the pipeline. At the inlet to the section, a time change in hydrostatic pressure is set, and at the outlet from the section a mass rate of gas flow is set. The initial distribution of gas-dynamic indices was taken for a stationary mode of operation. The equations were transformed to the equations of direct and reverse traveling waves presented in dimensionless variables, and approximated by an implicit scheme, taking into account the direction of excitation propagation. The iterative processes were formed by virtue of the nonlinearity of equations and boundary conditions, A calculation program was developed that allowed studying the process dynamics depending on the time change in the inlet pressure and the outlet mass flow rate under a path change in the diameter and leveling height of the pipeline axis. The results of separate calculations on transient processes were presented, when, at the section outlet the mass flow rate increases abruptly, and the pipe diameter has a local increase according to a sinusoidal law.