bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of geostationary and low-orbit “round dance” satellite communication systems
Authors: Reznik S V , Reut D V , Shustilova M S 
Published: December 2020

Abstract
Modern satellite navigations systems utilize high-orbit (mostly geostationary) and low-orbit satellites. Both satellite types have their advantages and disadvantages. A global communication system requires at least three or five GEO satellites with a life of 10 years, with each satellite costing around $200 million. Low-orbit global communication systems of the “round dance” type must have from hundreds to thousands of satellites. Their orbit life can range from 2 to 5 years; their cost must be between $1 million and $20 million. At this stage, there is a wide range of means for launching communications satellites into orbit, a large range of metal and composite structural materials. In addition, there are methods of designing, manufacturing, and testing communication satellites, as well as software and hardware for satellite control have been developed. So, the problem of economic optimization of communication satellite constellations becomes relevant. The paper presents the results of the comparative engineering and economic analysis of two types of satellite constellations.
Basic principles for describing the process of vibratory with an external source of dynamic impact
Authors: Levchenko Elena , Pokintelitsa Nikolay 
Published: December 2020

Abstract
The modern development of mechanical engineering requires high quality manufacturing of machine parts. The production experience testifies that high requirements to the quality of surface treatment of the parts need to be improved, in particular, in the finishing and clearing operations (FCO). Progressive method of processing parts is vibratory (V) on machines with U-shaped containers. Despite the positive practical experience of vibratory using in mechanical engineering, this method faces a number of problems related to the development of its theoretical foundations: equipment and tools are still imperfect; in the initial stage are works on managing of the V process; it is insufficiently studied the mechanism of surface layer formation at V. These problems hamper further development and improvement of the vibratory, which is very effective by its technological capabilities, and limit its wider introduction into industry. Efficiency of processing is provided by the right choice of equipment, schemes, and modes of processing, types of working environments. The mass of loading in the container of the machine does not absorb all the energy transmitted by the vibratory machine, but only part of it, the other part is non-productively dissipated. Therefore, the choice of the constructive scheme of the machine, on which the redistribution of these energies depends, is a crucial step, both in its design and in the management of the machining process.
Use of repair-recovery compositions for reducing the adhesion of soils to working bodies of machines
Authors: Zenkov S A , Lkhanag D 
Published: December 2020

Abstract
This article discusses the impact of repair-recovery compositions on the process of buildup of the soil working bodies of earthmoving machines. Adhesive forces can be reduced by creating an intermediate layer at the interface between the phases of the system “surface of the working member - the medium to be treated. This layer serves as a screen for intermolecular interaction forces of phases, has a small adhesion and cohesive interaction and has a “lubricating” effect, i.e. provides the possibility of relative displacement of phase working surfaces. Experimental work is conducted in accordance with the mathematical theory of planning of experiments (plan Box 3). After handling of an experiment graphical dependences of effort of shift from a surface without repair and recovery structures and with use of repair and recovery structures were received. The experiments carried out showed that when the RVS is applied, the adhesion of the soil to the metal surface of the digger’s working member is reduced by an average of 18%.
Nonwoven polylactide fibers: properties and application
Authors: Tertyshnaya Yu V , Skorokhodova A N , Shibryeva L S , Ivanitskikh A S 
Published: December 2020

Abstract
Non-woven argofibers based on polylactic acid and poly-3-hydroxybuturate was obtained by electrospinning. An experiment on growing winter wheat (Triticum aestivum L.) on non-woven polymer substrates was carried out. High seeding qualities of wheat seeds are shown both in the control sample and on the fibers. It is determined that the mass of the plant, the length of the roots is greater in plants sprouted on non-woven fibers PLA and PLA-PHB. During the growth and development of plants, the resulting non-woven materials undergo biodegradation. Thermophysical parameters of nonwoven agrofibers were determined by differential scanning calorimetry.
Method for determining dynamic coefficient of friction of bodies
Authors: Borzilov Yu P , Yerovenko V N , Misirov D N , Semergey S V 
Published: December 2020

Abstract
To study the effect of the material and the roughness of the impact surface, the velocity of impact interaction and the properties of bodies on the value of the dynamic coefficient of friction, a shock testing machine is proposed that provides an impact contact effect on the bodies in a plane located at an angle adjustable from 0 to 45 ° relative to the normal line drawn to the point of impact, in the range of speeds from 12 to 72 m/sec. It is found that at an impact velocity of 25 m/sec with an increase in the angle of inclination of the impact steel plane, the angle of friction and the corresponding dynamic coefficient of friction increase in a linear relationship. The maximum values of angles φ and dynamic coefficients of friction f make: - for steel balls φ = 8.3°, f = 0.146; - for lead balls φ = 11.4°, f = 0.167; - for grains of the wheat φ = 6.8°, f = 0.12. The results obtained indicate that the elastoplastic properties and shape of the bodies do not have any significant effect on the angles of reflection of bodies from the impact plane.
Automated device for the differential application of herbicides in the near-trunk zone of fruit
Authors: Filippov R A , Khort D O , Kutyrev A I 
Published: December 2020

Abstract
The information on the justification of the design parameters of the spraying unit of the herbicidal sprayer is provided. A technical description of the operation of the sprayer with an automated system for deflecting the spray unit from the axis of the row is given. The results of field studies of the herbicidal treatment of fruit crops by an automated device for applying herbicides to the near-stem zone of the orchard using an additional air flow are obtained.
Improving the properties of wheeled steel during thermal repair
Authors: Gubenko S I , Ivanov I A , Kononov D P , Urushev S V 
Published: December 2020

Abstract

The purpose: to increase durability and life of railway wheels and to reduce the cost of purchasing new ones by restoring the mechanical properties of the metal rim and improving its structure. Methods: study using a multiple electron microscope and local X-ray spectral analysis of wheeled steel after induction thermocyclic processing at a high-frequency facility and in a state of delivery. Results: The structure resulting from induction thermocyclic processing - sorbit leads to the formation of compressive stresses, which has a positive effect on the efficiency of the surface of the wheel. As a result, the reliability of the wheel on accidental failures (cranks, chippings, etc.) is improved and, as a result, the safety of the operation of rolling stock is improved. Practical importance: the rational use of induction wheel heating technology will improve the efficiency of the use of rolling stock by significantly reducing the number of purchases of new wheel pairs.
Methodology for determining the professional qualities of motor vehicle drivers
Authors: Ageev Evgeny , Vinogradov Evgeny , Novikov Alexandr 
Published: December 2020

Abstract
This article examines the factors that affect road safety in the Driver-Car-Road-Traffic Environment system, and defines the characteristics of the actions performed that are necessary for the vehicle operator. The author’s version of improving the system of training candidates drivers, by determining the professional qualities of the system “driver-operator” of vehicles. The algorithm for checking the readiness of candidates for drivers is presented, taking into account individual personal qualities. To determine the quantitative parameter for assessing readiness to perform actions in the professional training system, the use of the graphical method “Spider CIS” is proposed, which allows determining the most optimal variant of the training system, and including additional classes, if necessary, taking into account individual and personal qualities.
Efficiency of using dump trucks BELAZ-75180
Authors: Lagunova Yuliya , Bochkov Vladimir , Horoshavin Sergey 
Published: December 2020

Abstract
A comparative analysis of operational characteristics when using a different type of chassis of BELAZ-75180 mining dump trucks was performed. It is shown that the choice of the type and means of mining transport is determined by several factors, and, first of all, the characteristics of the cargo being transported, the distance of transportation, speed of flights, and the leverage for the given period. The power of vehicles and the performance of a mining dump truck depend on the scale of work (cargo turnover). The dependence of energy consumption during transport work on a quarry on the average size of pieces of rock is disclosed. The analysis of the dependence of the number of backup dump trucks on their number operating in a specific period is given. As a result of the analysis of operational characteristics, it was found that the chassis type of the BELAZ-75180 mining dump truck significantly affects its performance.
Study of the process of introducing coordinated management on the principle of «green wave»
Authors: Dorokhin S V , Artemov A Y , Gigadlo A P 
Published: December 2020

Abstract
The article analyzes the existing types of road network management, considers the process of introducing coordinated management in more detail. The basic principles of the organization of this type of control using traffic lights are determined, the basic parameters of the traffic flow necessary for its organization are established. An experiment was carried out on the main city highway using a simulation product and a comparative assessment of changes in the main characteristics of the traffic flow before and after the introduction of coordinated control was made.
On the possibility of individual forecasting of reliability factors of mechanical transport units
Authors: Savin L O , Novikov A N 
Published: December 2020

Abstract
The paper considers an approach to predicting probabilistic characteristics of the time before the transition of critical MT units to a failure state, based on the use of quasi-deterministic models of the time drift of the parameters monitored during maintenance. This approach makes it possible to ensure implementation in practice of flexible maintenance of MT strategies in relation to various conditions of its operation.
Mathematical model for engineering tracked vehicle suspension system connections influence assessment
Authors: Sarach Evgeniy , Ivanov Aleksey , Kurasova Mariya , Tkachev Yaroslav 
Published: December 2020

Abstract
This paper is devoted to designing imitational mathematical model that can help in tracked vehicle, which has connected suspension system, motion smoothness research. In this paper advantages and disadvantages of existing mathematical models are analyzed which allow to evaluate different design choices expediency at designing stage. In order to take suspension system connections into consideration and evaluate the possibility of using the created mathematical model to study transport vehicle motion smoothness the existing rectilinear motion mathematical model, created by BMSTU scientists, was modified. Modeling was carried out in MATLAB Simulink program complex. The results of connected suspension system imitational mathematical model usage are demonstrated on solving the following problem: tracked vehicle motion smoothness comparison in case of using connected and independent suspension system. These results show that connections in suspension system, which were added to decrease chassis loads, do not influence the tracked vehicle motion smoothness in any way. Thus, the modified imitational mathematical model can be used for tracked vehicle, which has connected suspension system, motion smoothness research.
Efficiency assessment in transport service provision for the population of Orel city
Authors: Kulev M V , Kulev A V , Kuleva N S 
Published: December 2020

Abstract
The article discusses the main methods for quality of passenger traffic assessment, presents the main advantages and disadvantages of these methods. The questionnaire for interviewing passengers was developed, which includes questions about the gender and age of passengers, their social standing, the frequency of passenger transport use and its attractiveness to consumers. The efficiency of city public transport functioning assessment methodology based on the results of a survey of passengers using elements of the “Google Forms” service was also offered in the article.
Differential pressure sensor for hydraulic drive of traction vehicles
Authors: Fomenko N A , Burlachenko O V , Lyashenko A A 
Published: December 2020

Abstract
Hydraulic systems equipped with working bodies hydraulic drive are widely used in road construction, agricultural, reclamation, forestry, military-technical and other surface vehicles. Depending on the operating conditions and modes, hydraulic drive elements are subjected to self-destruction, for example, high-pressure hoses hydraulic system, which reduces the machines’ working life (resource), increases operating costs and worsens the environmental situation. There are various systems and methods for protecting the hydraulic drive to militate these negative consequences. The analysis of conditions, operating modes and factors affecting the machines’ hydraulic system state, methods and systems for protecting the hydraulic drive, the causes of high-pressure hoses of destruction and the negative impact of consequences on the environment shows that the problem of finding a new technical solution remains. A new design solution is proposed for protecting the hydraulic drive, which is equipped with two adjustable throttles, two reverse valves and a pressure drop sensor that includes a diaphragm forming the positive and negative chambers.
Study of relationship between lateral slip coefficient and indicators of tire linear stiffness
Authors: Abdulgazis A U 
Published: December 2020

Abstract
Based on the analysis of the recent study, the article delves into the unresolved problem of defining the influence of normal and lateral stiffness coefficients on the tire lateral slip. The authors propose a method to determine such influence of normal and lateral stiffness on the tire lateral slip coefficient. The obtained analytical expressions make it possible to calculate the lateral slip coefficients of the tires taking into account their design parameters, speed, normal and tangential reactions in the wheel road contact spot.
Vibroacoustic debugging technique for vehicle exhaust systems
Authors: Okunev A P , Ovchinnikov V A , Cherepanov L A , Epishkin V E 
Published: December 2020

Abstract
Influence of the exhaust system on the vibroacoustic comfort of a passenger car with a transverse power unit is considered. The methodology is presented which, when using road tests and calculating the exhaust system on the finite element model, allows to reduce the levels of vibration and noise from the exhaust system when changing to more powerful engines in serial passenger cars.
Impact of the variable stiffness section on the conditions of track and rolling stock interaction
Authors: Kurhan D , Kurhan M , Husak M 
Published: December 2020

AbstractRailway track stiffness is one of the main parameters that determine the track and rolling stock interaction. The inelasticity of the rail base may occur for two reasons: either as a consequence of the deteriorated condition of a track or due to the structural features of a section. As a rule, areas before bridges or tunnels are treated. Today, there are several options for relevant design solutions. The main purpose of this work is to determine the characteristics of a “railway track” object with which it can be represented in the rolling stock models in the simplest way possible but adequate for sections of transient stiffness. The railway track is introduced into the rolling stock model as a sequence of elements with which the wheels of the rolling stock interact. It is assumed that a single element in its characteristics must be equivalent to the track response when passing the wheel from one inter-sleeper section to the next one, that is, to reproduce a sequence that is cyclically repeated. Such a track element will be characterized by reduced mass, stiffness and dissipation factor.
Problems of the use of renewable energy sources in the structure of railway power supply
Authors: Ostapchuk Oleksandr , Kuznietsov Mykola , Kuznetsov Valeriy , Kuznetsov Vitaliy 
Published: December 2020

Abstract
The paper presents the main indicators of the renewable energy sources in the railway transport structure of European countries. A new structure of railway power supply systems, energy storage systems and control algorithms under the conditions of stochastic mode of renewable energy sources operation are defined as the main problematic issues. Further directions for sustainable development of such systems and factors that influence the modes of operation of traction substations and electric networks were identified. Average power and a random component are two criteria that were used to build local systems. The paper presents the real schedules of daily load on the traction substation terminals and solar insolation with determined power distribution changes. The power deviations indicators depending on the time interval and the type of generation were determined. A normal law of distribution of a random component was determined as a result of all calculations. It is possible to determine the shortage or excess of electric power in the local system in a certain area and to plan the direction of its development in the near future by analyzing the nature of the determined average power change.
Study of railway traffic safety based on the railway track condition monitoring system
Authors: Kliuiev S , Medvediev Ie , Khalipova N 
Published: December 2020

Abstract
The solution to the problem of monitoring the railway track, as well as potentially dangerous objects and phenomena in the adjacent territories, is determined by the need to implement increased requirements for traffic safety (primarily to the geometric parameters of the devices of a long railway track under construction and functioning load-bearing highways), prevention of technological disasters and large-scale negative effects of natural phenomena on the railways. The continuous process of integrating methods and means of monitoring and preventing emergencies into a single information management system is shown. The possibility of determining a dynamic model of the adverse effect of the train on the track and the most unfavorable for the track train and traction parameters, which must be avoided when forming trains in this section, is established. Three key factors are formulated, the use of which will reduce the negative impact on the track from trains. The concept of information technology improvement of the monitoring system for potentially dangerous sections of the railway on the basis of new innovative technologies has been developed.
To the problem of train running safety
Authors: Pshinko O M , Ursulyak L V , Zhelieznov K I , Shvets A O 
Published: December 2020

AbstractThe paper is presenting the procedure used for establishing the cause of the wagon derailment. To do this, the computer simulations and the computational software, developed in the Dnipro National University of Railway Transport (DIIT) were used. The level of longitudinal forces and the wagons dynamic performance have been evaluated using the mathematical models of longitudinal oscillations of a train and the spatial vibrations of wagons, in particular of tank wagons. As a result of modeling we obtained oscillograms of longitudinal forces in each inter-wagon connection, the dependence of the largest longitudinal forces on travel time and distance traveled, the distribution of the maximum longitudinal forces along the train length, the speed dependence on travel time and track coordinates. We also obtained the dynamic performance of wagons: the vertical dynamics coefficients of the axle-box and central suspension, the horizontal dynamics coefficients and the derailment stability coefficient. The influence of the movable load in the tank wagons and the characteristics of rail irregularities on the stability coefficient against wheel climbing onto the rail is also considered. The presented methodology was used to determine the cause of the tank wagon derailment in a non-homogenous freight train consisting of 50 wagon tanks on an existing track section of the Lithuanian railways. When simulating the train movement, it was assumed that the train was equipped with elastic-friction absorbing devices and air distributors, turned on to the average operation mode. As a result of numerical experiments, an assumption was made about the cause of the train derailment.
Track circuits adjusting calculation method under current influence traction interference and electromagnetic compatibility
Authors: Razghonov S , Kuznetsov V , Zvonarova O , Chernikov D 
Published: December 2020

Abstract
The problem of railway transport electromagnetic compatibility automation systems in recent years has been aggravated by the use of power frequency converters in electric transport drives, which significantly increase the efficiency of traction characteristics of 3-phase electric engine. However, estimate relevant harmonic levels in the frequency range used in track circuits of railway automation and telemechanic systems. The paper provides theoretical justification for practical measurements of interference. It is shown, that the interference coefficients monotonically increase in the following cases: 1) increase in the value of the harmonic frequency; 2) increase in the propagation constant, taking into account the supports resistance of the contact network; 3) increase in the circuits track length. Operating frequencies of tonal track circuits up to 800 Hz, the interference increase rate in given length of the rail circuit slows down. The increase in interference coefficients depending on the mentioned factors is explained by the fact that with current part growth of the harmonic flows from the traction substation through the earth increases and thereby creates currents asymmetry of the track circuits.