bluuebunny/crossref_metadata_2025 huggingface dataset:
Power plant on the basis of internal combustion engine with gas dropping in the technological furnace of oil refining plant
Authors: Mrakin A N , Vdovenko I A , Afanaseva O V , Ageev M A , Selivanov A A , Batrakov P A
Published: January 2020

The main results of the evaluation of the technical and economic indicators of power plants based on internal combustion engines (ICE) that are integrated into the refinery process cycle are considered. The statistical processing of commercial offers has been carried out, which allow to evaluate capital investments in the main power equipment. The results of the calculation for the operating conditions of the power plant on its own gas of refining showed a good investment attractiveness of the project. The calculations found that the influencing factors can be ranked in descending order of importance: the cost of electricity, the rate of discount, capital investments in the object, the fee for the power supported for the reserve from the power system. Since the generator voltage of the internal combustion engine is 0.4 kV, the economic efficiency of the proposed power plant will be higher than the considered base case and it is advisable to produce electricity supply in the factory network on the low voltage side.
Evaluation of the accounting the AVR of the generator in the power system model in the study of the subsynchronous resonance
Authors: Rysev D V , Rysev P V , Shulga K S , Meshalkin O V
Published: January 2020

The article discusses the model of the power system taking into account the automatic voltage regulator of the generator at the occurrence of a self-clearing fault on the line. In this case, the grid contains series compensation. The generator is an electromechanical system consisting of a turbine and a synchronous generator with an excitation system. Time plots of rotation angles deviations of rotating parts of turbine, twisting torques, and also plots of maximum deviations of rotation angles and twisting torques from the level of series compensation are shown with the indication of the area in which they grow in time.
Calculation studies of the ambient temperature variation influence on the gas tube boiler efficiency
Authors: Slobodina E N , Kikhtenko V A , Mikhailov A G , Gaak V K , Stepashkin I A
Published: January 2020

The ambient air temperature variation influence on the efficiency of the gas tube hot water boiler operating in the heat supply system is considered in the paper. The dependency graphs of the fuel consumption, temperature in the near-wall layer of the convective bundle on the gas side, and aerodynamic losses along the length of the fire tubes in the convection bundle on the ambient temperature were drawn. The basic calculation formulas used for the calculation, as well as the temperature chart of the heat supply system operation depending on the ambient temperature are presented.
The method of the research of residual gases in a tight case of quartz resonators
Authors: Belousov K A , Strunin V I , Khudaibergenov G Zh
Published: January 2020

Mass spectrometric analysis of closed-volume gases of quartz resonators-thermostats emitted by the materials used in the installation of the device. A measuring complex with a vacuum of 10−5÷10−6Pa has been developed. The mass spectra of the residual gases were obtained before the depressurization of the products in the DIL-14 housing. The temperature range of the study is 20÷160 °C.
Improved algorithms for determining the strain of optical fibers using Brillouin reflectometers
Authors: Bogachkov I V
Published: January 2020

The issues of improved algorithms for determining the strain of optical fibers using Brillouin reflectometers are investigated. Structure charts of devices for early diagnostics of optical fibers are presented. Adaptive algorithms for construction of Brillouin reflectograms: patterns of Brillouin frequency shift and strain distribution along the optical waveguide are considered. Reference Brillouin reflectograms for different optical fibers from the database are required to correctly detect the “problem” segments (segments of optical fibers with increased mechanical strain or with transformed temperature) in the optical waveguide.
Calculation of speech intelligibility considering primary transducers’ parameters
Authors: Ivanov A V , Kofanov D S
Published: January 2020

The main characteristics of primary transducers are considered. The experiment is carried out to estimate the level of self-noise in microphones and accelerometers. The measurements are taken in identical conditions for all the primary transducers. The statistics on acoustic and vibroacoustic noises in premises is gathered. Based on the findings, the algorithm to calculate speech intelligibility considering the primary transducers’ parameters is developed.
Developing an algorithm for creating the optimal spectrum of a masking noise considering a speaker’s diction
Authors: Ivanov A V , Shemshetdinova E E
Published: January 2020

The experimental research is carried out to build up a database with speaker’s voices. The structure of the database with speaker’s voice signals is designed. The software to calculate the optimal envelope shape of interference based on the speech samples is developed. The obtained interference is suitable to disguise voice signals of certain speakers in protected premises during the confidential conversation. Development prospects are described, and recommendation for further research is given.
Dependence of Error Probability on the telegraph Distortion Value
Authors: Kosykh A V , Kryzhanovsky D A , Khazan V L
Published: January 2020

The transmission of messages via non-stationary communication channels is made in conditions of adapting the receiving and transmitting equipment to the communication conditions. Mode of adaptation to communication conditions requires rapid assessment of the communication channel quality. The most obvious criterion for assessing the quality of a non-stationary communication channel is the constantly changing value of the elements error probability in the transmitted message. However, assessing the error probability of message elements requires significant time intervals, which may exceed the time of stationary state of the communication channel. It is known that the error probability of message elements is uniquely related to the value of telegraph distortions. The estimation of the telegraph distortion value requires much less time compared to the time required to estimate the probability of errors. In this case, the indirect estimation of the error probability by the value of the telegraph distortion can be made relatively quickly at an interval that is many times less than the stationary state interval of the communication channel. In this regard, the possibility of indirect estimation of error probability in terms of telegraph distortion is relevant for receiving and transmitting equipment with adaptation to communication conditions.
The characteristics of the band-pass filter from the various parameters of the substrate
Authors: Quan D M , Hung L Q
Published: January 2020

In this work, the design of a band-pass filter implemented on L-resonators is investigated. On one side of the substrate there are transmission lines responsible for the input and output of the structure. On the second side of the substrate are the resonators themselves. Studies have shown that to obtain a higher frequency band, a substrate with a high dielectric constant value is required. The thickness of the substrate affects the size of the filters. This filter is technologically easy to implement using standard methods of manufacturing printed circuit boards.
The monitoring channel of the random process parameters with the simplified structure in discontinuous conditions variation
Authors: Danilov S N , Naimov U R , Belyaev M P , Pudovkin A P , Varepo L G , Panasyuk Yu N , Belyaev P S
Published: January 2020

The modern requests of movement trajectory monitoring of any devices like a car or an aircraft as well as e.g. power facility parameters make one solve the task of measuring devices development which can stable operate at the extremal unexpected both coordinates variation and their derivatives. Such task can be solved by monitoring measuring devices synthesis with changeable characteristics and structures depended on the situation mainly based on variable combination of the state models. Both the functioning and simplified algorithm of the measuring system based on the synthesis technique was developed. The algorithm system consists of two simple linear filters, residual comparing scheme and estimate choice one. The both algorithms formed by the system theory technique and simplified with selection mode give the concurrent assessments.
Evaluation of Probability Errors in Condition Monitoring of Heat-Exchange Equipment
Authors: Demin A M , Naumenko A P , Gorchakova A A , Odinets A I
Published: January 2020

This paper focuses on problems of selecting and defining boundary values for criteria in condition assessment of diesel hydrotreating process units’ heat-exchange equipment. The objective of this paper is to define critical parameters of heat exchangers operation. Substantiation of the selected condition assessment criterion is presented. The value of the proposed criterion was calculated using statistical data relevant to the condition assessment of heat-exchange equipment and probabilistic-statistical methods of decision making.
The control system simulation technology for optimization and determination of the feasible parameters domain
Authors: Denisova L A , Meshcheryakov V A , Karabtsov R D
Published: January 2020

This paper focuses on the simulation technology for optimization of the automatic control system (ACS) parameters vector to be tuned and to provide a stable operating mode eliminating self-oscillations. A hybrid approach (synthesis of optimal control methods and simulation research) for designing ACS using genetic algorithms is presented, which allows taking into account constraints when searching for the optimal solution. Simulation of the ACS was performed using the software tools MATLAB / Simulink / Global Optimization Toolbox. It is shown that the proposed technology for determining the domain of recommended tuning parameters is effective for computer-aided design of ACS, it allows to significantly improve the quality of control and reduce the time spent on pre-setting developed controllers.
Computer model of a gas path in a microturbine unit
Authors: Korotkiy V A , Khmarova L I
Published: January 2020

Microturbine units are used for autonomous supply of buildings and engineering facilities with heat and electric energy. Gas path of a microturbine unit contains a combustion chamber and a set of gas-burners which provide mixing of the natural gas with the air, followed by total combustion of the obtained gas-air mixture. The known structures have two essential disadvantages which reduce operational efficiency of a gas turbine as part of the microturbine unit. The first disadvantage is caused by inhomogeneous nature of the “gas-air” flammable mixture, which leads to an incomplete combustion of fuel and emission of nitrogen oxides harmful for the environment. The second disadvantage is connected with a loss of mechanical strength of structural elements exposed to the impact of high-temperature products of combustion. The article proposes methods of boosting the resource of a combustion chamber by enhancing its mechanical durability with a simultaneous reduction of the content of nitrogen oxides in flue gases. The first method is in the use of power elements installed inside the combustion chamber. The second method of boosting the resource of the combustion chamber is connected with accurate profiling of windows through which cylindrical gas-burners get inserted. The third method is based on improving the quality of mixture formation in the casing of the gas-burner. Combined application of the proposed modification activities allows reducing the extent of harmful emissions as well as boosting the resource of the microturbine unit.
Modeling of shaping process and analysis of gear wheel cutting process by means of AUTOCAD and ANSYS software
Authors: Lyashkov A A , Murashev G E
Published: January 2020

In the present paper methodology of computer aided geometric modeling of formation of workpieces with periodic teeth machined with centroid enveloping method is developed without involving complex mathematical apparatus. During its application, as opposed to already known methods, simultaneous modeling of two objects of formation – wraparound and removed contents – takes place. Analysis of configurations of solid models of cutaway layers and respective removed content volumes allows a design engineer to intentionally set the optimal values of tool advance parameter and number of passes. The key point of the present paper is to establish logical connection between geometric computer simulation of removed contents in CAD environment and analysis of chip formation in the process of cutting using ANSYS software. In the present paper AutoCAD 3D simulations rendering of cutaway layers is shown along with the corresponding realistic simulation of chips, created using metal cutting process finite element analysis software. Due to substantial difficulties of cutting process 3D simulation, it is considered reasonable to perform computer simulation of cutaway layers geometry generation on the first stage of problem solving. This will allow us to choose the optimal cutting parameters and consequently speed up the cutting process simulation.
Analysis and trimming operations in the problem of spatial formation of a family of offset curves given an area with islands
Authors: Myasoedova T M , Panchuk K L
Published: January 2020

In the present paper an algorithm of determination and trimming of non-working segments of offset curves generated for an area and a number of islands within it is considered. The algorithm is based on cyclographic method of spatial formation of offset curves given curvilinear boundary contours of an area and islands within it. Methods of analysis and corresponding algorithms of trimming of non-working segments of offset curves are considered for the cases of self-intersection of offset curves. The analysis and trimming operations form the basis of the proposed algorithm of spatial formation of offset curves. The calculations that accompany every stage of formation process are exact and not based on iteration algorithms. The acquired analytical solution to the problem of generation of a family of offset curves significantly facilitates cutting tool trajectory calculation and control programming in pocket machining on NC units.
Algorithmic presentation of light-sensitive layers printing monitoring in-process
Authors: Nagornova I V , Bablyuk E B , Varepo L G , Trapeznikova O V , Lazareva O V
Published: January 2020

In the study the in-process monitoring algorithm for the flexible printed LED-pixels production at the light-sensitive layers formationstage is presented. The light-sensitive layers are based on either polymethine dyes complexes or luminophores. The both chemical and electrostatic interaction between the light-sensitive compounds and the bottom functional layer affected on crystallization conditions as well as the previous layer relief and thermal postprocessing parameters including next layers formationare most significant production factors. The production layers defects are determined. The optimal stages of optical properties monitoring are defined. The in-process optical properties monitoring technique is offered.
Cyclographic images of Bezier Splines
Authors: Panchuk K L , Lyubchinov E V
Published: January 2020

In the present paper the analysis of impact of smoothness of connection of spatial curve segments on smoothness of connection of its cyclographic images constituting a cyclographic projection of the curve is presented. The spatial curve is represented by a Bezier spline consisting of Bezier segments of constant order connected with a certain order of smoothness. Formation of Bezier splines consisting of segments of equal order (from two to five) and formation of respective cyclographic projections is considered. Reduction of order of smoothness of connection of segments of cyclographic projection with respect to the order of smoothness of connection of corresponding segments of the Bezier spline is discovered. Numerical experiments were conducted, their results confirm the theoretical conclusion. Recommendations on Bezier spline selection in practical tasks based on connection of segments of cyclographic projection of spline with certain order of smoothness are given.
Video quality control by determining the frame average color
Authors: Proskuriakov N E , Yakovlev B S
Published: January 2020

In modern conditions, despite variety of hardware-software complexes for creation and promotion of multimedia projects, still big problem is the optimum choice of codecs and settings of quality of operations of rendering depending on tasks of developers or a site on which there will be further a material. In most cases now «optimum parameters» of video rendering are understood as creative activity of the person which on the basis of visual survey, specific and subjective ideas of quality of «picture» of a product, has to receive balance between «quality» of the picture and final file size. In fact, now practically there are no tools in order that it is simple to compare two identical videos on quality and to make quantitative quality evaluation of the video file. Therefore, this direction of researches is important and actual. The main objective of work - to define possibility of use of average color of frame and a color difference for quality evaluation of the video files received at different settings of rendering. Results of pilot studies of determination of average color and a color difference for frame of the video file are provided. Experimental and analytical means revealed possibilities of application of this method for quality determination the video file and findings of differences from the original. As showed research, the most high-quality codecs are H265, DivX and MPEG2. In addition, it was set that DivX showed the greatest stability on a color difference. The offered method can be applicable for a provisional estimate of quality of the received movies since average color does not consider the accuracy of some, important parameters, for example, text clearness on frame. It well copes with the general determination of video frame quality.
Dynamics and Control of a Two-Spacecraft Coulomb Formation: Challenges and Prospects
Authors: Aslanov V S
Published: January 2020

The paper is devoted to the issue of active large space debris removal. The contactless method of influencing space debris through the electrostatic interaction is considered. The main advantages of this method are possibility of space debris removal in geosynchronous orbit with low energy costs and absence of a dangerous and complex stage of space debris capturing or docking. This paper introduces the trends and features of a relative attitude dynamics and control of the two-spacecraft coulomb formation. The advantages of the multi-sphere method are discussed for modeling and analyzing the attitude motion of space debris. Two towing schemes (push or pull) are studied in detail. It is shown that the pushing scheme has distinct advantages. The features of the attitude motion of the towed object are identified including chaotic phenomenas and control laws of attitude motion are presented. In the final, the possibilities removal of non-functioning GEO satellites of complicated configuration using electrostatic tug are discussed.
Dynamic model of the mechanical drive with automatic continuously variable transmission on the basis of Appell’s equations
Authors: Balakin P D , Dyundik O S , Zgonnik I P
Published: January 2020

The design approach is based on to mechanical systems is implemented by adaptive properties to the actual parameters and to the operating conditions in the synthesis of the mechanical drive on design stage allows to implement many technical solutions of mechanical transmission with qualitatively new properties. Using for the adaptation additional motion of the links to the main one, it is possible and important to get auto-CVT with the transfer function dependent on the level of the transmitted power flow. The design of the auto-CVT which is potentially capable to provide full use of the available power in the mechanical drive, stationary and energetically perfect mode of operation of the engine at variable type of external loading is considered. Mathematical model of mechanical auto-CVT obtained by using Gibbs function – the acceleration energy. The results of the research are on the basis of which it is possible to perform design calculations of the links and connections of the auto-CVT, including its automatic control chain.
Automatic control a stiffening of links as a means of adaptation of mechanical systems
Authors: Balakin P D , Dyundik O S , Zgonnik I P , Fedorova M A
Published: January 2020

The publication presents some technical solutions of mechanical systems created on the basis of gears, the design of which includes additional elements with nonlinear properties.

The characteristics of such elements with automatic control stiffness control allow to implement a universal design approach mechanical systems providing the property of adaptation to variable external loading of mechanical systems at the design stage, while improving the dynamic quality of the system.
Experimental studies of arcjet thruster in pulsed mode of operation for corrective propulsion systems of small spacecraft
Authors: Blinov V N , Fedyanin V V , Shalay V V , Yachmenev P S
Published: January 2020

The paper presents the results of experimental studies of an arcjet thruster in pulsed mode of operation on nitrogen with a thrust value of up to 32 mN and energy consumption of up to 30 watts. The pulse mode of operation of the arcjet thruster is provided by the developed power source. At measured values of temperature at the nozzle and pressure in the arc chamber of the engine in a pulsed mode of operation define the basic characteristics of gas-dynamic functions of gas flow. The forecast of the achieved values of the specific impulse when using ammonia as a working fluid is carried out
Advanced design of friction piles for operation in complicated soil conditions
Authors: Gruzin A V , Gruzin V V , Rusanova A D
Published: January 2020

Development of advanced designs for friction piles is a problem solution to reduce material costs at the stage of a pile foundation construction in complicated soil conditions. The constructive approach aimed to a rational use of construction materials in production of piles is proposed in this paper. The idea of technical proposal is to change a shape of a pile cross-section to increase the length of a perimeter limiting the area, invariable in a size. An equilateral triangle cross-section meets fully these requirements. Results of theoretical studies and the analysis of existing calculation method of bearing capacity of a friction pile in a foundation soil showed a possibility of practical implementation of this engineering approach. The utilization of a pile with a cross-section in a shape of equilateral triangle increases bearing capacity of a pile in a foundation soil up to 28.6 % in comparison with a round cross-section and up to 14 % compared to a square cross-section. Conducted laboratory studies confirmed the correctness of theoretical calculations. The application of obtained results of theoretical and laboratory studies in the construction of pile foundations in complicated soil conditions will not only reduce material costs for the foundation production, but will also decrease transportation costs which are rather high under development of new fields.
Technological process modeling for ink filling in the high accuracy screen printer mesh
Authors: Hilal H A , Litunov S N , Belkova S V , Bochkareva S S , Trifonova E N
Published: January 2020

Printed electronics is a modern direction in developing technology of electronic components production. The purpose of the work is to control the thickness of the conductive pattern on the print obtained by screen printing. The task of the study is to develop a mathematical model for ink filling the screen mesh. The calculations took the speed of the dosing squeegee of 2…20 cm/s, inclination angles of 75°…105°. The design pressure is in the range of 2082.08…34604.2 PA, the estimated depth of ink filling the mesh is 25…280 microns.
The experimental method for testing relaxation of pneumatic elements with a rubber-cord casing
Authors: Korneyev V S , Korneyev S A , Shalay V V
Published: January 2020

The method for the experimental study of the viscoelastic properties of pneumatic elements with a rubber-cord casing is proposed. Based tests of relaxation in which the height of the pneumatic element is kept constant (a practically incompressible fluid is used as the working medium). The implementation of the method is illustrated by the example of the rubber-cord casing of the balloon type of model N-50. The value of the absorption coefficient (relative hysteresis) is established, which in order of magnitude coincides with the value of the absorption coefficient of tread rubbers given in literary sources. In the process of holding the height of the pneumatic element at a constant level, increments of the force of the pneumatic element and overpressure are proportional to each other with a proportionality coefficient depending on the value of the internal volume and height of the air element. The comparative analysis of the features of the operation of pneumatic elements in cases where the working medium is a gas or liquid is done. The results obtained are of interest in the development of vibration protection and vibration isolation systems for technical objects, the design of which includes air springs, air damping shock absorbers and rubber-hydraulic vibration mounts.
The experimental method for determining the geometric characteristics of pneumatic elements with rubber-cord casing
Authors: Korneyev V S , Korneyev S A , Kvasov I N
Published: January 2020

The method for experimentally constructing the geometric characteristics of pneumatic elements with rubber-cord casing at zero and quasi-zero pressure is proposed. The practical implementation of the method by the example of the rubber-cord shell of the balloon type of model N-50 is illustrated. The processed experimental data in an analytical form presents the empirical dependences of the internal volume on the height of the pneumatic element at zero and quasi-zero overpressure. The obtained parameters are mandatory for the model of air spring and study the damping phenomenon. The results obtained are intended for the development of vibration protection and vibration isolation systems for technical objects, the design of which includes air springs and air damping shock absorbers.
Application of Hermite splines for load movement on a flexible crane suspension through a curvilinear trajectory
Authors: Korytov M S , Shcherbakov V S , Titenko V V
Published: January 2020

Analytical expressions of the coordinates of the load, the suspension point and the rope deviation angle, as well as their first three time derivatives were obtained by setting the desired load movement trajectory on a pendulum type flexible crane suspension using two-point Hermite splines with the quartic highest derivatives. A well-known mathematical model of the oscillatory system described by a linearized differential equation was used. With the described movements, the uncontrollable pendulum oscillations of the load are absent. The load moves exactly along a reference trajectory. The superposition of load movements in two mutually perpendicular planes solves the problem of synthesising the suspension point trajectory, which ensures the movement of load along an arbitrary smooth curvilinear trajectory in the horizontal plane. The second horizontal coordinate of the load was represented as an interpolation polynomial from the first horizontal coordinate. The division of the movement trajectory along the axis of the second horizontal coordinate into several sections of the same length provide the determination of the load movement and its derivatives at reference points, as well as the calculated suspension point trajectory. The developed technique is promising for application in intelligent mechatronic control systems for travelling and bridge-travelling cranes.
Research of accuracy of industrial robot at work as part of flexible machining cells
Authors: Morev D S , Blokhin D A , Koltzov A G
Published: January 2020

In this paper, the factors affecting the accuracy of an industrial robot with an articulated kinematic as part of flexible production modules were analyzed. The accuracy of the circular movements of the robot gripper depending on the position in the working area and the load applied to the robot. A method for measuring stiffness using a laser interferometer and optics for measuring straightness is proposed. According to the results of the experiments, the types of errors were determined, causing the greatest error in the accuracy of the industrial robot movements. Recommendations on the need to measure certain types of errors when setting up flexible production modules are given.
Longitudinal stress waves in viscoelastic and plastic rods
Authors: Proskuriakov N E , Lopa I V , Zverev I V
Published: January 2020

Dynamic loading of rod construction from viscoelastic and plastic material is considered. For a task solution on distribution of a wave of tension of compression in a rod, the interconnected hypotheses, which allowed receiving an analytical solution, offered. Convenient analytical representation of tension distribution of a rod longwise for the wave of compressing tension of extending in viscoelastic and plastic material of a rod at blow to its end face tough weight is offered. Satisfactory approval of results of numerical calculations and data of the previous researchers that does use of this method practically feasible for a solution of applied tasks is shown.
Simulation modeling of the assembly process
Authors: Revina I V , Trifonova E N
Published: January 2020

In the article the models allowing one to simulate performance of assembly process in terms of conveyor production are developed. The technological process of assembly production is a complex system depending on a number of production factors, such as the parameters and modes of equipment operation, the level of work skills, the type of production, etc. The relevance of the study is to identify bottlenecks in the organization of the production process and answer the question "what if" when considering different models of the assembly process. The purpose of the work is to assess the impact of production factors (number of operators, operating parameters and type of conveyor, failures in the conveyor operation) on the implementation of the assembly process and to justify the effectiveness of each model of the assembly process economically. For modeling the operating technological process of assembly was considered. The obtained results showed that, depending on production factors, productivity can vary by 4.5 times. The best of the considered options is the use of the accumulation conveyor, where the profit would be 13485.26 $. The worst one is the accumulation conveyor with failures on one of the operations and complete standstill of the assembly line to fix them. On implementing such a scenario, production profit would be 2981.15 $.
Contact pressure in interference joint with modified grooves of shallow depth
Authors: Ryazantseva I L , Fedorova M A , Zgonnik I P
Published: January 2020

The analytical method for determining the magnitude of the contact pressure in a cylindrical interference joint with shallow depth grooves is described in the publication. This method takes into account the geometric features and the relative position of the external members.

The calculated dependences are based on the Lame’s formulas are given in the publication. They can be used to assess the bearing capacity of the joint at any macrogeometry of the joint, independently of the number, shape, size of grooves and their location.

The method is different by simplicity and visibility. It provides sufficient accuracy of results for engineering calculations.
Restoration of the current signal from solar panels of AIST small spacecraft for estimate the parameters of the rotational motion
Authors: Sedelnikov A V , Ivashova T A , Safronov S L
Published: January 2020

The paper deals with the problem of estimating the rotational motion parameters of the prototype of the small spacecraft "Aist" using data on the current from solar panels. The spectral analysis of the signal is carried out. The continuous signal was restored by its discrete readings using the Kotelnikov series. The angular velocity of the rotational motion of the prototype of the small spacecraft "Aist" is estimated. A comparative analysis of the results with the results obtained by other authors. Conclusions are drawn about the changes in the parameters of the rotational motion of the prototype of the small spacecraft "Aist" during its orbital flight.
Methods of the analytical study of vibratory drum forced vibrations during the soil compaction
Authors: Tarasov V N , Boyarkina I V , Boyarkin G N , Serebrennikov V S
Published: January 2020

The fundamental principles of the vibration theory as a classical science are widely used for the description of movements of technical objects and mechanical systems. Vibrations of real objects are complicated by non-linear characteristics of stiffness of the medium to be compacted and viscous friction forces. Usable vertical movements of a vibratory drum have been determined whereby the technological compaction operation of materials and soils is performed. The methods of the vibratory drum vertical movement determination have been developed by means of considering the vibratory drum downward movement during the semi-period of one rotation of the eccentric weight. The operating process of the road roller vibratory drum is composed of sequential periodic transient operating processes of the material compaction and idle cycles in each turn of the eccentric weight rotation. Within the process of the study the operating process is considered of the vibratory drum downward movement during the material compaction, consisting of free damped and undamped forced downward movements of the vibratory drum. For the first time the damping time of transient processes during the analysis of forced oscillatory processes is regulated by the semi-period time of the eccentric weight rotation t = 0.5T.
Study of the dynamic processes of the vibratory drum rebound from the compacted surface
Authors: Tarasov V N , Boyarkina I V , Boyarkin G N , Serebrennikov V S
Published: January 2020

Fast dynamic processes of material compaction by vibration rollers represent random dynamic processes, wherein characteristics of the strength of compacted material, humidity, temperature, types of materials and their characteristics change stochastically. However, from the total set of these processes it is possible to single out such processes, which belong to the category of random ones because of their insufficient state of knowledge but they are deterministic. Such processes may include the vibratory drum dynamic vertical movements during the material compaction. In the process of the study the vibratory drum downward and upward movement modes are considered under the action of the dynamic driving force, which while projecting onto a vertical axis turns into a harmonic force acting periodically downwards and upwards and it is a deterministic parameter. Other mass and kinematic characteristics of the vibratory drum are also deterministic ones. On the basis of classic laws of dynamics the vibratory drum bouncing dynamic processes in the final stage of the compaction technological process and accompanying process of the vibratory drum vertical downward movement have been analytically considered. The necessity to solve such problem is justified by the fact that the dynamic process parameter determination by experimental methods is connected with significant physical and material expenses. New knowledge has been obtained that is necessary for the improvement of the vibration roller designs and modes of their operation.
Impact of ultrasonic exposure and external pressure in a closed volume on the temperature of the evaporated liquid
Authors: Trushlyakov V I , Lesnyak I Y , Novikov A A
Published: January 2020

The influence of ultrasonic exposure (UE) and external pressure on the process of heat and mass transfer during liquid evaporation is studied, which is an urgent task, since UE is widely used in various technological processes, and the parameters of UE and external pressure determine their effectiveness. Experimental studies of the effect of UE and pressure in a vacuum chamber on the temperature of the evaporated liquid at a constant ultrasonic frequency of 25 kHz and an amplitude of ultrasonic vibrations of 2 μm were carried out. The dependences of the change in the relative load on the amplitude of the oscillations of the bottom of the bath with a change in pressure in a closed volume are obtained, and coefficients are determined that refine the thermal physico-mathematical model of the wave processes in a liquid with ultrasound and a change in external pressure in a closed volume. The liquid temperature from the initial moment of time sharply increases from 27.7 ° C to 32.8 ° C, and then, when the pressure in the vacuum chamber reaches 45 kPa, it gradually decreases until an ice crust forms on the liquid surface. A comparative analysis of the results of mathematical modeling, taking into account the use of refinement coefficients and the results of experimental studies showing that the discrepancy between the temperature of the evaporated liquid, from the initial moment of time to the moment of formation of cavitation bubbles on the surface of the liquid, is 8%. The discrepancy between the temperature of the evaporated liquid from the moment of formation of cavitation bubbles to the freezing point of the liquid is up to 50%, which is explained by the error in measuring the temperature of the liquid with thermocouples during the formation of cavitation bubbles.
Thermomechanical method of increasing the mechanical properties of cermets
Authors: Vasil’ev E V , Popov A Yu , Chernykh I K
Published: January 2020

Thermomechanical method of increasing the mechanical properties of cermets leads to a buildup in the durability of cutting tools up to 2 times. However, after thermomechanical processing, a defective layer of 0.8 mm in-depth forms on the outer surface of the processed workpiece, which is caused by of the oxidation of WC tungsten carbide. In order to prevent oxidation on the workpiece surface, it is proposed to use a nickel coating, which reduces the oxidation of WC by more than 30 times when it is heated to a temperature of 1000 °C.
Development and Research of an Experimental Prototype of the Positive Displacement Two-Stage Piston Hybrid Energy-Generating Machine
Authors: Zanin A V , Shcherba V Ye , Nosov E Yu , Paramonov A M , Blinov V N , Khrapsky S Ph
Published: January 2020

This paper considers the new principle diagram of the positive displacement two-stage piston hybrid energy-generating machine. A prototype of the two-stage piston hybrid energy-generating machine has been developed based on the analysis of working processes and frames of piston hybrid energy-generating machines, as well as by using preliminary theoretical studies. This prototype allows to visualize the movement of the liquid piston in the second stage of the machine. A set of experimental studies on a previously developed and modernized test bench made it possible to prove the working capacity of the prototype, to measure the main thermodynamic and discharge parameters, and to identify the main features of the ongoing work processes.
Spent coal mines using for the industrial wastewater disposal
Authors: Bondareva L , Zakharov Yu
Published: January 2020

Industrial wastewaters disposal, in particular wastewaters appearing from the coal extraction and enrichment, is an important national economic task of preserving environment. At the same time, the applied wastewater disposal technologies must be ecologically safe and do not requires large financial expenses. This task is quite relevant for Kuzbass due to territory saturation of the coal, metallurgical and chemical industrial enterprises. The paper discusses a mathematical model of one of these technologies -the wastewater treatment in spent workings of closed and flooded coal mines. The proposed mathematical model allows studying the treatment processes occurring in the flooded mine workings, that using numerical experiments and taking into account the slurry water characteristics and changes of the incoming groundwater volume and of the injected wastewater volume. The process of suspended in mine waters coal and rock particles sedimentation and sediment compaction is given special attention in the model. Numerical experiments results, that allowing estimating the safe time mine act as a wastewater treatment plant, are presented.
A survey of Free Partially Commutative Groups
Authors: Duncan A J , Remeslennikov V N , Treier A V
Published: January 2020

A partially commutative structures are widely used in concurrent computations, robotics and pure algebra. This paper is a short survey of free partially commutative groups and RAAGs.
Multi-step probabilistic assessment in the problems of identifying indicators functioning of the gas distribution network
Authors: Khodzhaev N Sh T , Ganieva N A , Gostev N V , Khodzhaev T T
Published: January 2020

The paper poses and solves the problem of applying the method of multi-step probabilistic assessment in the problems of identifying indicators functioning of the gas distribution network. Gas distribution networks in operation are often subject to emergency situations. This causes the implementation of the restoration work on the basis of experimental a priori information. In this regard, computational experiments make it possible to produce predictive values of the performance indicators of the gas distribution network and, accordingly, to identify them with real data.
Investigation of the propagation of waves of sudden change in mass flow rate of fluid and gas in a “short” pipeline approach
Authors: Khujayev I , Bozorov O , Akhmadjonov S
Published: January 2020

The problem of the propagation of waves of sudden change in mass flow rates originated at the ends of a pipeline of a finite length is formulated and solved analytically in the paper. In the process of modeling, it was assumed that the route change in pressure is due to the local component of the inertia force, and the velocity of propagation of waves of small pressure disturbances depends on the elastic properties of the pipeline material and fluid. The Dirichlet problem with respect to mass flow rate is solved by the Fourier method and a periodic solution is obtained in the form of a functional series. Instead of solving the Neumann problem with respect to hydrostatic pressure, a pressure solution is obtained by integrating the mass conservation equation over time, where the known solution of the problem with respect to mass flow is used. The options for using the solution for cases of low and super compressible fluids, as well as for studying the propagation of longitudinal waves in an elastic rod, are discussed. According to analytical solutions, a series of calculations was carried out for the problems of instantly closing the inlet and/or outlet sections of the functioning area, as well as for the problem of gas pumping into the elementary section of the pipeline. The features of the propagation of compression and rarefaction waves in the context of the above tasks are investigated. Some graphical results are presented and analyzed.
Fuzzy cultural algorithm for solving optimization problems
Authors: Muhamediyeva D T
Published: January 2020

Cultural algorithm demonstrates incompetence in solving problems of multi-extremal optimization. This is due to the large dimensionality of the data and causes premature convergence. To solve this problem, a fuzzy cultural algorithm is proposed.
Formalizing the search of targets with given coordinates distribution
Authors: Nartov B K , Poluyanov A N
Published: January 2020

The paper presents a new approach to formalizing the tasks of an optimal search of the targets with given coordinates distributions. The main problems of formalizing this task group are highlighted. The method is described, that allows one to avoid non-analytical limitations on search units control. The formalization scheme for optimal search planning problems is shown. The features of real-time search control are considered for the cases, when the moments and coordinates of target detection are known. The search simulation results partially verifying the proposed method are given.
Modeling of a profile of blades of the water-wheel with energy return optimization
Authors: Panichkin A V
Published: January 2020

In work approach for numerical realization of definition of difficult borders with a current of a thin layer of ideal liquid on the surface of the working blade of the water-wheel is considered. The technique of creation of firm borders in two-dimensional and three-dimensional cases for streams of such layer of liquid with application of power optimization is presented. Test calculation of an optimum surface of blades of the water-wheel at the maximum return of kinetic and potential energy by liquid on the basis of use of the principle of a maximum was considered.
COMPUTING FUZZY INTEGRAL OF THE BASIS OF FUZZY MESURE
Authors: Primova H A , Sotvoldiyev D M , Raximov R T , Bobabekova X
Published: January 2020

The fuzzy integral of a function with a fuzzy measure is a general estimate in the form of a nonlinear convolution of particular estimates of information elements, and the possibility of interconnection of information elements is not excluded. Here is an approach that allows the expert to best formalize his fuzzy ideas, transforming the language of words into a language of quantitative estimates.
Non-linear mathematical model to predict the changes in underground water level and salt concentration
Authors: Ravshanov N , Daliev Sh
Published: January 2020

An urgent problem related to the process of change in underground water level and mineral salt transfer in soils is solved in the paper. The problem is described by a system of partial differential equations and the corresponding initial, internal and boundary conditions of various kinds. To derive a mathematical model of the process under consideration, a detailed review of scientific papers devoted to various aspects and software of the object of study is given. To conduct a comprehensive study of the process of filtration and change in salt regime of groundwater, mathematical models and an effective numerical algorithm are proposed taking into account external sources and evaporation. Since the process is described by a nonlinear system of partial differential equations, it is difficult to obtain an analytical solution. To solve it, a numerical algorithm based on a finite-difference scheme is developed, and an iterative scheme is used for nonlinear terms, the convergence of the iterative method is checked. In the conclusion of the paper it is shown that the developed mathematical apparatus can significantly reduce the volume of field experiments on monitoring and predicting the level of groundwater and salt concentration and minimize expensive and resource-intensive experimental work.
Weakly equationally Noetherian trees II
Authors: Shevlyakov A N
Published: January 2020

We give necessary and sufficient conditions for a tree semilattice to be weakly equationally Noetherian (see [4] for more details).