Introduction. The issue considered in the article is of relevance due to the innovative vector of modern social and economic development, as well as to the inevitability of transition to the new, sixth, technological order based on a knowledge-intensive mode of production. Processes associated with mastering emerging technologies actively proceed now in the world’s leading economies. The strategic competitiveness of Russia is limited by the state of productive forces and the level of development of industrial relations. To rectify the present situation an impetus that can accelerate the dynamics of economic processes is necessary. The aim of the study is to identify the role of juvenile potential in ensuring sustainable economic development, as well as to determine the conditions for its provision and implementation as a factor in the transition to the sixth technological order. Materials and Methods. The research methodology was based on the general scientific methods (those of scientific abstraction, unity of the historical and the logical, analysis and synthesis, induction and deduction, comparison and analogy) and the special methods of cognition (the integrative method that implies the necessity to analyze economic, social, legal and other prerequisites). The information base of the research was made up of official statistical data, legal acts, and scientific works in the field of human and juvenile potential. Results. On the basis of the identified system of indicators of juvenile potential, an assessment of its elements and conditions of its fulfillment as a factor in reproduction of productive forces of the sixth technological order was carried out. The revealed disproportions and the negative factors that caused them make it possible to determine the conditions for effective realization of juvenile potential as a social resource for progressive development of the Russian economy in a strategic perspective. Discussion and Conclusion. The scientific importance of the obtained results consists in the elaboration of the scientific concept of juvenile potential, its conceptual and categorical framework, as well as in the systematization of theoretical approaches to the development of performance indicators. The results can be used to substantiate promising directions of socio-economic, youth, and education policies, as well as those dealing with organization and monitoring of socio-economic development of the state and territories.
Introduction. It is impossible to take into account all the forces acting in the process of mathematical modeling of dynamic processes. In order that mathematical models the most accurately describe the dynamic processes, they must include the terms that correspond the constant perturbations. These problems arise in applied tasks. In this paper we consider the case when the system allows for the partial equilibrium position. The aim of this work is to prove the stability theorem for the partial equilibrium position at constant perturbations, which are small at every instant. Materials and Methods. The research objects are nonlinear systems of differential equations that allow for a partial equilibrium position. Using the second Lyapunov method, there are proved the stability theorems for the constant perturbations of the partial equilibrium position, which are small at every instant. Results. Together with the introduction of stability for a part of the variables, it has become necessary to introduce stability for the part of phase variables under constant perturbations. The first stability theorem of the part of phase variables under constant perturbations was obtained by A. S. Oziraner. In this work, we prove a theorem of the stability of the constant perturbations of the partial equilibrium position, small at every instant. It should be noted that there is no stability theorems of constant perturbations for the partial equilibrium position. Thus, the theorem proved in this work is of a pioneer nature. Conclusions. The theorem 3 proved in the work is the development of the mathematical theory of stability. The results of this work are applicable in the mechanics of controlled motion, nonlinear system.
Introduction. The article substantiates the necessity of determining the slippage of the tractor wheels during testing. The principle of operation and design of the sensors used to determine the slippage of the driving wheel in the testing of tractors and agricultural machines are considered; design features and characteristics of common shunting sensors based on a rotating disk with slots through a fixed angle are noted. The authors analized advantages and key disadvantages of existing sensors, such as the complexity of mounting and the need to manufacture the sensor mounting parts for a specific tractor model. The aim of the study is to develop a universal slip sensor for testing wheel and tracked tractors. Materials and Methods. The proposed solution determines the positions of the driving wheel in three-dimensional space on the basis of the inertial navigation system. The principles of operation of inertial navigation system components are described. The system consist of an accelerometer, a gyroscope and a magnetometer. The basic mathematical digital orientation filters applied for processing raw data are analyzed. Results. The design of the tractor slip determination device is developed. The main element of the mechanism is an inertial wheel position sensor. The selection of the main components of the sensor is substantiated: name and model of the inertial navigation system, the digital orientation filter and the microcontroller for the functioning the sensor. As a result of the research, the position sensor of the driving wheel was designed and manufactured on the basis of the MPU-9250 inertial navigation system and the STM32F405 microcontroller. The sensor software was developed in C language. A digital filter was based on the Madgwick algorithm for real-time data processing. Discussion and Conclusions. The result of the research was the development of a sensor for slipping the tractor wheels based on an inertial navigation system. This type of sensor is devoid of the main disadvantages of the widely used sensors of driving wheels. The advantages of the sensor are easy installation and method of wireless data transfer.
Introduction. The problem of mathematical modeling in innovative technologies is the lack of a developed general model of innovation processes. The existing approaches allow simulating innovations from any one part: political, economic (in various aspects) or describe the general structure of innovative activity. For example, innovations can be estimated such indicator as sales volume of an innovative product. However, it does not mean that there are no other indicators or they are not important. Materials and Methods. The models by L. Leydesdorf and S. Kauffman, including NK model originally used for the analysis of development of biological populations, were chosen for research of the model choice problems of the innovative integrated structure between university, the enterprise and research laboratory. Results. Modeling the innovative integrated structure between participants of process is carried out based on expert assessment of the innovative landscape for a case of the maximum interdependence. Conclusions. A brief description of modeling methods in innovative technologies is presented in this article. The general description of the problem sphere is given. The current state of researches of this problem is specified. The imitation of innovative networks development options based on the NK model at the independent strategy of participants is constructed. The case of the maximum complexity of network when all participants of an innovation are interconnected and also local and global optimum in a landscape of projects payback is considered.
Introduction.Ensuring the safety of country food industry in terms of the duration of storage and the quality of products is impossible without sterilizing products in autoclaves. The effectiveness of the sterilization processes depends on the degree of their automation. In the last twenty years, the improvement of automatic and automated control systems was primarily based on the development of technical means for automation without theoretical justification of decision-making. The proposed work is aimed at identifying the links between the parameters and connections of the sterilization process and the choice of structural and parametric features of the control system. Materials and Methods. A qualitative analysis is carried out based on the modern theory of automatic control for an approximative model of the thermal process of steam heating in an autoclave, taking into account the laws of heat transfer and the sufficiency of using a twodimensional model depending upon the structural and functional features of the model, which have regard to the parameters and relationships of the process, namely, the Kalman’s controllability properties of the model in the time domain in the state-space representation (the transition from the transfer function with zeros in the numerator to the normal differential system differential equations is also described). There were also analized the stability properties of the model in the frequency domain by means of transfer functions and structural transformations and the relationship of parameters in the form of inequalities with the subsequent choice of proportional-integral-differential configuration components for a real autoclave using the matrix of expert estimates. Results. It is shown that to make a qualitatively study of the issues of controllability and stability of the approximative model of the thermal process of water heating by steam in an autoclave, depending on the process parameters, it is necessary to represent the model the time domain (in the state-space representation) and in the frequency domain (in the form of transfer functions). The analysis of the controllability of the process is based on three approaches: the first (formalized) approach is based on the representation of the model in the form of a normal system of ordinary differential equations in the Cauchy form with the development of a method of decreasing the order of the higher derivatives of coordinates and introducing additional control signals taking into account the control derivatives; the second (unformalized) is based on the exclusion of management derivatives through structural transformation; the third (direct) approach uses the first-order heat balance and heat conduction equations derived from physical considerations. Under the conditions of Kalman’s controllability, dependencies between the parameters of the process and the degree of its controllability have been obtained.The analysis of the stability of the process is based on studying the poles of the transfer functions in the frequency domain and the characteristic roots of the equations of state in the time domain. On the basis of structural transformations, a closed canister heating loop with water with inertia, depending on the autoclave charging parameters, is isolated. Transient processes in this circuit take an amplifying, aperiodic or integral character, which affects the nature of the transient processes of the control system as a whole. The formalized choice of the components of the proportional-integral-differential regulation law is carried out depending on the frequency of application of the degree of loading and the need for the components of the proportional-integral-differential regulator using the matrix of expert estimates. Conclusions. The results of the research will serve as the material for the development of a real model of the autoclaving process, taking into account the static and dynamic characteristics of measuring, conversion and actuating elements, investigating the influence and compensation of inertia and nonlinearities of real elements, followed by the development of an automated system for controlling the sterilization process in autoclaves. The results of the work can be used to study general and applied problems of optimal control in both food and other industries, for example, in the production of building materials and the production of rubber products.
Introduction. The paper explores an impact of mixed fuel on the performance of the tractor in the process of agricultural work. The aim of the study is to obtain quantitative indicators of Belarus 922 tractor. The mixed fuel consists of diesel and rapeseed oil. Materials and Methods. The operational research of the tractor with the installed set of instruments and equipment was carried out in the conditions of agricultural production. Results. We obtained quantitative performance of Belarus 922 tractor running on pure diesel oil and on mixed fuel consisting of 60 % diesel and 40 % of rapeseed oil in plowing the soil and in processing before sowing. The analysis of the data showed a change in the specific performance indicators of the tractor running on the mixed and diesel fuel during agricultural processing. When plowing Gт value increased from 11.86 to 12.54 kg/ha, the amount of NOx increased from 344.4 to 373.2 g/ha, CO value increased from 136.9 to 137.1 g/ha, C value decreased from 11.2 to 8.04 g/ha. When processing the soil before sowing Gт value increased from 4.61 to 4.86 kg/ha and NOx value from 137,9 g/ha to 151 g/ha, CO value decreased from 60.7 to 45.6 g/ha and C value decreased from 6.52 to 4.04 g/h. Conclusions. The test results demonstrate the expediency of using mixed fuel to improve the performance of Belarus 922 tractor in agricultural production.
Introduction. The composite materials have not been widely used in the Russian economy (especially in agriculture) until recently. It is relevant to use them for manufacturing some parts of agricultural machinery, for example, racks of cultivator paws. These parts often break down because of stress concentration in the places where their thickness changes during the time of plowing. The stress can be decreased by using com- posite materials. Materials and Methods. This paper presents the study results on the use of composite materials for manufacturing of cultivator racks with the appropriate selection of the volume ratio of fibers in each of the layers of fabric and layers of binder. Results. Based on the results, the design safety factor was calculated to be equal to 2. It should be noted that the values of the mechanical characteristics of the material changed because of the presence of a porosity coefficient, which was 11.6 %, while the allowable value was 4%. Field tests have shown the durability of a new composite material, even under severe operating conditions, compared to a conventional rack made of alloy steel. Conclusions. Studying the mechanical behavior of the rack geometric model and modeling a material with high mechanical properties, which later was used for manufacturing a composite material, we could get the minimum safety factor of 4, with the maximum safety factor for workers – 15. The racks from composite material are economically feasible as less expensive than used steel racks.
Introduction. The method of electrospark alloying of metal surfaces was proposed by the Russian scientists B. R. Lazarenko and N. I. Lazarenko. It is possible to apply this process to the surface of the workpiece from any conductive materials of a hardened alloyed layer of material to ensure high hardness, heat resistance, wear resistance and other properties of the executive surfaces of the parts. The paper shows the possibility of formulating criteria for determining the efficiency of the electrospark alloying process and the properties of the doped layer, depending on the properties of d-elements determined by their position in the periodic table and a number of (s+d)-electrons of electrode materials. A similar approach to determining performance criteria can be recommended for other high-energy materials exposure processes. Materials and Мethods. The authors used steel 45 as the material of the rim sections and refractory d-metals of IV-VI groups: Ti, V, Cr, Zr, Nb, Vo, Hf, Ta, W; а также d-metals: Mn, Fe, Co, Ni, Cu, Zn, Pd, Ag, Cd, Re, Os, Ir, Pt, Au and p-metals: Al, Bi, Sb, Sn, Pb as anode materials for creating doped layers. The installations used for electric-spark alloying: EFI-10M, EFI-46A, EFI-25M, EFI-66, Electrom-10, ELFA-541, Elitron-22, IMEI-01-2A; Corona- 1101; microscope MII-4, MIM-10, BIOLAM-M, EMA-100, Axiosplan-2; Profiler P-201 “Caliber”; microthermometry PMT-3M, DUH-W201, Shimadzu. In the study of erosion there we used the installation of “Atovic absorption spectrophotometer, Varian AA-4”. The generator GOS-3OM and installation SLS-10-1 wer used for laser processing. Results. The generalization of the schemes of the process of electric-spark alloying in single and repeated exposure of the model anode material was made. At the cathode there is a hole with a different degree of filling of the cathode material or representing the zone of mutual crystallization of the anode material and the cathode. When exposed to spark discharge in a gaseous medium, there are differences in the formation of holes due to the more intense transfer of eroded material to the opposite electrode, especially to the cathode. Dependences of some properties (microhardness, melting point, elastic modulus) of refractory d-metals on their location in the IV–VI periods of the periodic table are obtained and presented. Dimensional and volumetric relations of d-elements in electrospark alloying were established, depending on their location in the periodic table. Dependences of the properties of model electrode materials on the statistical weight of atomic stable configurations, as well as the dependence of the erosion of the anode of transition metals on the number (s+d)- electrons and the interelectrode medium. The patterns of d-metals erosion under electrospark alloying and other types of high-energy impact to the surface have been found. Conclusions. Based on the results of this research, it can be stated that in order to achieve higher coating properties and greater efficiency of electrospark alloying, it is necessary to give preference to anodic materials having the maximum statistical weight of atomic stable configurations. It can be said that the properties of the electrode materials relate to their erosion amount and the parameters of the efficiency for forming the doped layer during electrospark alloying, which for specific conditions are determined by the method of selection of ratios and comparison with quantitative experimental data of previously established dependencies. A common approach to the formulation of criteria for imparting new properties to materials by high-energy impacting on them is possible. There is formulated a hypothesis for determining similar change dependences of the physical and operational properties of d-elements on their location in the periodic Table and the statistical weight of atomic stable configuration for various methods of local high-energy impact.
Introduction. The problem of reliability of hydraulic drives sealing joints remains unsolved. However, the current level of computer modeling tools development allows us to solve effectively the problems of their longevity by replacing laborious experiments with high-performance computing. This paper presents the results of the approbation of the author's methodology for realizing computational approaches to determining the life of sealing joints on the basis of circular cross-section seal of hydraulic booster for MTZ (Minsk Tractor Works) tractors. Materials and Methods. The determination of mobile sealing joints resource is based on the author's methodology, which used ANSYS for realizing a series of accelerated loading cycles that simulates real operating conditions. The developed models consider the processes of wearing, relaxation and hydrodynamic effects acting in a sealing joint. Results. The use of the finite element modeling tools made it possible to determine the change in the stress-strain state of the power steering tightener in MTZ tractors during operation. The mechanism of joint tightness restoration on the basis of self-packing effect is revealed. The comparison of the forms of sections, obtained as a result of numerical and micrometer studies, confirms the effectiveness of the proposed methodology and the adequacy of the results obtained. The analysis of the obtained graphs shows that under normal operating conditions, the life of the sealing joint “cylinder ‒ piston” and “rod ‒ cover” is 2 and 1.12 years respectively, and as the temperature and pressure of the hydraulic fluid increase, decreases exponentially. Conclusions. The results of the study show the high efficiency of the author's methodology. This technique can be used in researches to determine the resource and criteria for the leak-tightness of sealing joints. The graphs of the dependence of the sealing joints life on temperature and hydraulic pressure allow companies, specializing in the creation and repair of hydraulic drives, to develop schedules of preventive measures for their maintenance considering a complex of operational factors. Keywords: seal, O-ring, hydraulic drive, reliability, life, service life, wear, relaxation, ANSYS, finite element analysis Acknowledgements: The study was supported by the Russian Foundation for Basic Research and the Government of the Republic of Mordovia in the framework of the project “Obtaining and research of new composite polymeric materials containing finely dispersed and nanosized modifiers for machine tribo-conjugation elements” (Grant No. 18- 48-130007а_р). For citation: Kuznetsov V. V. The Resource of Movable Sealing Joints with the O-Ring Seal. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):562–582. DOI: https://doi.org/10.15507/0236-2910.028.201804.562-582
Introduction. In small enterprises with simplified technological process of graded milling, preparations, which involve cleaning, peeling and moistening grain, play an essential role for ensuaring high quality of graded flour. Modern equipment for the low-productive mills implies only dry cleaning of grains in an abrasive machine with their further cold conditioning. The equipment designed for graded milling with deep multiple cleaning, washing and hydrothermal treatment is not possible. It significantly increases the cost of flour. The aim of the study is to increase both qualitative and quantitative indicators of graded flour in small enterprises through peeling and drying of grains before milling. Materials and Methods. The quality analyses of grain processing according to such indicators as ash content (whiteness), moisture, quantity of fractured grains were carried out according to State Standards of the Russian Federation and the methods established in science and practice. The degree of peeling was determined by the whiteness indicator with a photoelectric whitener SKIB-M (GOST 26361-2013 “Flour. Test method for whiteness”). Grain moisture was determined according to GOST 13586.5-2015 by the drying cabinet DEC-3M (drying electrical cabinet, model type 3M). The number of fractured grains was determined according to GOST 30483-97. Results. The research result revealed the dependence of grain processing on the technical aids. А combined peeling–drying machine was developed on this principle. The authors have developed rational operations of grain processing, which increase the whiteness of the received flour on average 4–7 conventional units. The standard instrument for whiteness definition has been studied and set. According to the given results optimal operating parameters for grain processing before milling have been developed: machine productivity (Q = 700 kg/h); the period of grain processing (t = 72 s.); optimum moisture content (from the point of view of obtained flour whiteness) of grains received for milling (W = 14 %); radiant power (P = 1 000 W). Conclusions. The research proved the fact that peeling of grains is one of the most effective ways of increasing the grade of end products of small enterprises with simplified technological process of graded milling. The efficiency of peeling seeds of wheat with humidity higher than 16 % decreases that speaks for the need to dry grains. The authors of the article introduce the equipment and technology for grain processing before graded milling, which provide grain peeling and, if necessary, drying. The operating parameters of the peeling-drying machine for preparation of grains for milling have been determined. The developed technology provide, if necessary, drying the remoistened grain to necessary standards that gives the chance to produce high-quality flour from the grains processed hydrothermally without processing moisture conditions required. The machine productivity in the mode of drying should be connected with the power of microwave infrared radiation, and its time and power should be limited to a maximum permissible grain temperature, which does not exceed 60 ºС. Keywords: peeling, whiteness, moisture, drying, preparation of grain for grinding For citation: Anisimov A. V., Rudik F. Ya., Zagorodskih B. P. Technological Improvements of Grain Preparation for Milling in Small Enterprises. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):603–623. DOI: https://doi.org/10.15507/0236-2910.028.201804.603-623 Acknowledgments: The study was conducted as part of an agreement with the Foundation for Assistance to Development of Small Enterprises in Scientific and Technical Sphere (No. 180GS1 / 6784, 25 December 2014) under the “START-1” program together with “Healthy Food” LLC.
Introduction. The paper provides an analysis of numerical methods for solving the Cauchy problem for nonlinear ordinary differential equations with contrast structures (interior layers). Similar equations simulate various applied problems of hydro- and aeromechanics, chemical kinetics, the theory of catalytic reactions, etc. An analytical solution to these problems is rarely obtained, and numerical procedure is related with significant difficulties associated with ill-conditionality in the neighborhoods of the boundary and interior layers. The aim of the paper is the scope analysis of traditional numerical methods for solving this class problems and approbation of alternative solution methods. Materials and methods. The traditional explicit Euler and fourth-order Runge-Kutta methods, as well as the implicit Euler method with constant and variable step sizes are used for the numerical solution of the Cauchy problem. The method of solution continuation with respect to the best argument is suggested as an alternative to use. The solution continuation method consists in replacing the original argument of the problem with a new one, measured along the integral curve of the problem. The transformation to the best argument allows obtaining the best conditioned Cauchy problem. Results. The computational difficulties arising when solving the equations with contrast structures by traditional explicit and implicit methods are shown on the example of the test problem solution. These difficulties are expressed in a significant decrease of the step size in the neighborhood of the boundary and interior layers. It leads to the increase of the computational time, as well as to the complication of the solving process for super stiff problems. The authenticity of the obtained results is confirmed by the comparison with the analytical solution and the works of other authors. Conclusions. The results of the computational experiment demonstrate the applicability of the traditional methods for solving the Cauchy problem for equations with contrast structures only at low stiffness. In other cases these methods are ineffective. It is shown that the method of solution continuation with respect to the best argument allows eliminating most of the disadvantages inherent to the original problem. It is reflected in decreasing the computational time and in increasing the solution accuracy. Keywords: contrast structures, method of solution continuation, the best argument, illconditionality, the Cauchy problem, ordinary differential equation For citation: Kuznetsov E. B., Leonov S. S., Tsapko E. D. The Parametrization of the Cauchy Problem for Nonlinear Differential Equations with Contrast Structures. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):486–510. DOI: https://doi.org/10.15507/0236-2910.028.201804.486-510 Acknowledgements: This work was supported by the Russian Science Foundation, project no. 18-19-00474.
Introduction. The study deals with enhancement of an automotive diesel engine duty cycle through fumigating air charge by the certain dose (10−20 %) of hydrocarbon activator (alcohol, gasoline, kerosene, biodiesel, etc.). This is a relevant problem in engineering. In spite of its effectiveness, this method has not yet been widely applied to machinery. The existing mechanical devices for fumigating air charge do not provide the exact dosage of activator and its timely supply in a diesel engine at different operating modes. Materials and Methods. The solution for this problem may be the development of an automatic system for the multi-point fumigation of air charge. This device performs the injection of activator into the diesel engine intake manifold branches with the help of electromagnetic injectors managed by the electronic control unit. The system should provide the injectors operation by the algorithm for the cylinders firing order and calculate the injection duration for the adjusted activator dose. For the programming of the Electronic Control Unit, the injection duration of the exact activator dose was theoretically calculated. The algorithm of electromagnetic injectors operation was substantiated (for D-243 tractor diesel engine by the example). Results. To implement the multi-point fumigation of air charge, it was determined that depending on the activator dose and the engine speed and load mode, the cyclic dose of activator amounts may be from 1 mg per cycle to 13 mg per cycle, while the activator injection duration is from 0.27 ms to 3.5 ms. For the practical realization of the multi-point fumigation of air charge for D-243 diesel engine of MTZ-82.1 tractor the automatic system was designed. The system consists of an activator tank, filter, electric pump, rail, pressure regulator, electromagnetic injectors, electronic control unit, fuel consumption sensor, and sensor of phase and crankshaft speed. Conclusions. The device solves the problem of the automatic fumigation of air charge at the intake stroke and helps to improve power, fuel economy and environmental indicators of the automotive diesel engines. Keywords: diesel engine, fumigation of air charge, activator, system, electromagnetic injector, electronic control unit, sensor For citation: Ryblov M. V., Ukhanov D. A., Ukhanov A. P. Developing the Automatic System for the Multi-Point Fumigation of Air Charge in the Diesel Engine. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):523–536. DOI: https://doi.org/10.15507/0236-2910.028.201804.523-536 Acknowledgements: The authors thank the engineer of PNIEI company A. V. Grunyushkin for help in invention of Electronic Control Unit and in programming of microcontroller; the President of GAKS-Armservis Research and Manufacturing Association, D.Sc. (Engineering), professor S. V. Seynov for help in manufacturing of the modified intake manifold for diesel engine. Special thanks to anonymous reviewers for the objective analysis of the article.
Introduction. The problem under consideration is relevant to production processes associated with the longitudinal movement of materials, for example, for producing paper webs. For these processes transverse disturbances, which in the vertical section are described by the hyperbolic equation of a longitudinally moving string, are extremely undesirable. That gives the problem of damping these oscillations within a finite time. Materials and Methods. To solve the problem of damping the oscillations, the authors suggest reducing it to the trigonometric problem of the moments at an arbitrary time interval. When considering moving materials, the construction of the basis systems forming the moment problem is a special challenge, since the hyperbolic equation contains a mixed derivative (Coriolis acceleration). Therefore, the classical method of separating variables is not applicable in this case. Instead, a new method is used to find self-similar solutions of non-stationary equations, which makes it possible to find the basis systems explicitly.Results. In the case of paper web, it is necessary to find a minimal in the whole class of admissible perturbations time interval, within which the trigonometric system forming the problem of moments is the Riesz basis, that make it possible through using the system conjugate with it to find the optimal control way in the form of a series and, therefore, to build a so-called optimal damper. Conclusions. As a result of the study, a generalized solution of the problem of transverse oscillations is constructed. For the problem of damping oscillations, the exact damping time is obtained, namely, a time T0 at which the total energy of the system is zero. Optimum control is found in the form of a Fourier series.Keywords: damping oscillations, hyperbolic equation, Coriolis acceleration, trigonometric moment problem, Riesz baseFor citation: Muravey L. A., Petrov V. M., Romanenkov A. M. The Problem of Damping the Transverse Oscillations on a Longitudinally Moving String. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):472–485. DOI: https://doi.org/10.15507/0236-2910.028.201804.472-485Acknowledgements: The work was supported by grant No. 16-01-00425 A from the Russian Foundation for Basic Research.
Introduction. The influence of ultrasound parameters on the properties of processed lubricating oils and wear characteristics of friction pairs is a relevant problem in agricultural engineering. The paper presents a simple method for influencing on the lubricating oil by ultrasonic vibrations of the optimum frequency and power that results in reducing the wear of the interfaces of mechanisms and machines. The authors study the change in the physical characteristics of the oil during its ultrasound treatment and the assessment of their effect on the wear of a friction pair during long-term tests. Materials and Methods. We used a generator with variable signal parameters, a lever scale, a burette and an alcohol thermometer to assess the change in coefficient of surface tension of engine oil during sonication. Long-term tribotechnical tests were carried out on 2070 CMT-1M friction machine according to the “roller ‒ pad” scheme. The mass of these samples after long-term tests was weighed by Sartorius company analytical scales with a measurement accuracy of 0.00001 g. A profilograph-profilometer of Taylor Hobson Company was also used. Results. As a result of the research, the optimum frequency and power of ultrasound were revealed for lubricating oil processing. The decrease in the surface tension coefficient of oil was more than 5 %. With prolonged wear tests, the wear factor was reduced by 28 %. Conclusions. The effect of increasing the wear resistance of friction pairs when exposed to ultrasound oil is associated with a decrease in its surface tension coefficient, which allows the oil to be distributed with minimal effort over the surfaces with forming a film of sufficient thickness, which increases the bearing capacity of rubbing surfaces. Keywords: wear, surface tension coefficient, motor oil, tribotechnical test, ultrasound For citation: Simdiankin A. A., Davydkin A. M., Slyusarev M. N., Zemskov A. M. Evaluation of the Influence of Motor Oil Ultrasonic Processing on the Wear of Friction Pairs during Long-Term Wearing Tests. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):583–602. DOI: https://doi.org/10.15507/0236-2910.028.201804.583-602 Acknowledgments: The study was conducted with the financial support of the Ministry of Education and Science of the Russian Federation (state task, direction: development of competencies) project no. 11.3416.2017/4.6 “Development of technologies and tools to improve the durability of parts, assemblies, machines and equipment by creating nanostructured coatings sources of concentrated energy”.
Introduction. The article explores the stress-strain state of a distribution pair of aggregates of a volumetric hydraulic drive and the search for ways to increase its durability. Materials and Methods. In the process of studying, the generally accepted principles of the theories of friction, reliability, elasticity, mechanisms and machines, and mathematical modeling were used. To simulate the stress-strain state, an engineering analysis system ANSYS was used. Distribution pairs of hydraulic pumps 313.3.112, GST-112 and Sauer Danfoss 90R075 were chosen as objects of study. Results. As a result of the study there were obtained values of the real contact stresses and long-term current stress on the distribution of pairs of units of volumetric hydraulic drive: the 313.3.112 hydraulic pump is 26,93 MPa; for GTS-112 water pump is of 22.21 MPa for the Sauer Danfoss 90R075 hydraulic pump is 27,12 MPa. It is revealed that the area located on the discharge side is a subject to the greatest loads. This is the cause of one-sided wear of spherical surfaces, which is quite common in units decommissioned. The values of contact stresses in the joints hardened by the method of electric spark machining are on average 1.4 and 9.4 % lower than in not unhardened. In the process of electric spark machining there is a redistribution of stresses on the surface that leads to a decrease of the operating load in the connections. Conclusions. The study allowed modelling the stress-strain state in new and hardened distribution pairs of volumetric hydraulic drive units under operating conditions and suggesting ways to increase its durability. It was established that to increase the wear resistance of a resolving compound and the durability of the volumetric hydraulic drive aggregates, it is necessary to ensure that in distribution pairs the maximum bearing capacity is greater than the maximum long-term operating load in these connections. To solve this problem, it is proposed to create coatings with high tribotechnical properties by the method of electricspark machining. Keywords: resource-limiting compound, volumetric hydraulic drive, modeling, finite element method, bearing capacity, operating load, wear resistance, electrospark machining For citation: Ionov P. A., Senin P. V., Stolyarov A. V. Modeling of Stress-Strain State in Connection Resource Defines of Volumetric Hydraulic Drive. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):537–551. DOI: https://doi.org/10.15507/0236-2910.028.201804.537-551 Acknowledgements: The study was conducted with the financial support of the Ministry of Education and Science of the Russian Federation (state task, direction: development of competencies) project № 11.3416.2017/4.6 “Development of technologies and tools to improve the durability of parts, assemblies, machines and equipment by creating nanostructured coatings sources of concentrated energy”.
Introduction. The aim of this work is to develop the main guidelines of project and operations management at machine-building enterprises. Materials and Methods. The authors reviewed the state of application of the project and operations management of machine-building production in the automated mode. The review showed the complexity of its application due to a large number of factors, which must be taken into account when implementing. An approach was developed that allows solving the task using the automation of analysis processes and decision-making in production management. Results. The article establishes the main guidelines of the project and operations management, aimed at increasing productivity and reducing production costs based on modeling the state of production environment. It also defines the requirements for the model. A prognostic time model for forecasting the state of the enterprise production system has been developed. Conclusions.The tasks have been solved in this article allow increasing the level of automation of the processes of project and operations management of the enterprise in the conditions of quick-change production. The implementation of the developed approach to project and operations management of the enterprise will allow streamlining the launch of products with a reduction in the amount of work in progress and increasing the productivity of output.Keywords: technological process, project and operations management, design, prognostic model, production, labor intensity, productivityFor citation: Tsyrkov A. V., Kuznetsov P. M., Tsyrkov G. A., Yermokhin Ye. A., Moskvin V. K. Project and Operations Management of Machine-Building Production. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):511–522. DOI: https://doi.org/10.15507/0236-2910.028.201804.511-522
Introduction. The article presents new solutions for designing the equipment for final processing parts with a complex profile of working surface. The said solutions allow a planetary rotation of the part at a small center distance of the mandrel with the workpiece and the spindle of the installation. This solution improves the quality of the working surfaces and reduces energy costs. Materials and Methods. The disadvantage of modern devices for final processing of complex parts is the increased energy consumption and the large axial distance between the part and spindle. These factors reduce the quality of processing and the part range in terms of weight and dimension characteristics. The application of new solutions to change the design of the installation is relevant. When designing a new installation, the center distance between the part and the spindle was reduced. This contributed to the reduction of vibrations, improving the quality of surface treatment and increasing the product range. Results. The calculations to reduce the resistance of the abrasive medium affecting on the surface of the diesel engine turbo-compressor wheel blades confirmed the expediency of the solution. The calculations of the part for deflection by using Solid Works 2016 software were carried out. The calculations demonstrated the reliability of the installation when processing parts of medium and large sizes as compared to the basic installation option previously made by Penza State University for Penzadieselmash Company. Conclusions. The calculations made it possible to find that the reduction of the center distance reduces the deflection of parts and vibration in the process of finishing and allows stabilizing the quality and performance of processing the surfaces of a complex profile with less energy coast. A new design of the installation was developed and manufactured. It contributes to planetary rotation of the part at a small axial distance of the mandrel with the part and the spindle of the device. Keywords: theoretical study, result of study, complex surface, part surface, loose abrasive particles, performance, quality indicator, equipment design, design calculation automation For citation: Skryabin V. А. The Installation for Processing of Parts with a Complex Profile of Working Surface. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):552–561. DOI: https://doi.org/10.15507/0236-2910.028.201804.552-561
Introduction. The current level of agricultural production, including horticulture, is determined by intelligent machine technologies and new generation technical means with modern information and instrument support. The implementation of digital intelligent agricultural technologies in industrial gardening requires a fundamental change in the paradigm of technical support, based on the development and application of new automatic and unmanned machines, equipment and software for managing work processes of machines, navigating technical means, controlling the implementation of technological operations, monitoring the yield of agricultural crops, analyzing diseases and pests on plants and other technological functions. Materials and Methods. 3D model is visualized in the computer-aided design “KOMPAS-3D” through using the methods of mathematical modeling, theoretical mechanics and optimal design. A prototype of an automated unit for magnetic pulse processing of plants is made. The program code for calculating the required movement of the actuator rod is developed in the Sublime Text editor. C++programming language was used. The functionality of the computer program is related to the capabilities of controllers STM32, Arduino Mega/ Uno/Nano. Nextion 2.4 (the TFT screen 320x240) for the graphical output and interaction was used. Results. An automated unit with the algorithm of the drive control system of working bodies were developed during the technological operation of magnetic pulse processing of plants, taking into account the agro-technological parameters of garden plantations. A computer program with both automat and remote control was designed for driving the working bodies. Conclusions. The unit allows introducing a new environmentally safe technological method of stimulating vital and growth processes of fruit crops. This device provides the most efficient operation through automatic adjustment to various agro-technological parameters of plantings, providing the required value of magnetic induction in the working area on plant objects in the field. Keywords: magnetic pulse processing, control system, automated unit, irradiation of plants, gardening, low-frequency magnetic field For citation: Smirnov I. G., Khort D. O., Filippov R. A., Kutyrev A. I., Artiushin A. A. Automated Unit for Magnetic-Pulse Processing of Plants in Horticulture. Vestnik Mordovskogo universiteta = Mordovia University Bulletin. 2018; 28(4):624–642. DOI: https://doi.org/10.15507/0236-2910.028.201804.624-642
Introduction. As a result of damage to agricultural and forestry machines from corrosion, the costs of maintaining their performance are increasing. The use of water-soluble inhibitors can slow or halt the destructive process. However, many of the inhibitors have disadvantages, for example, flammability or toxicity. The purpose of this work is to study the protective effectiveness of aqueous solutions of boric acid ester and triethanolamine and to develop recommendations for their use for anticorrosive protection of agricultural and forestry machinery in long-term storage. Materials and Methods. Protective compositions were prepared by dissolving boric acid ester and triethanolamine in distilled and industrial water at room temperature. Aqueous solutions with a concentration of water-soluble inhibitors of 5–50 g/l (0.5–5 mass %) were used for research. The linear polarization resistance method was used to assess their protective efficiency. Solartron (UK) measuring complex was used for electrochemical studies. Accelerated corrosion tests were carried out on steel plates according to GOST 9.054-75 in the g-4 humidistat. The aftereffect of water-soluble corrosion inhibitors was evaluated by the residual film protective efficiency. Results. The influence of the concentration of the ester of boric acid and triethanolamine in aqueous solutions for their protective properties is studied. It was found that boric acid and triethanolamine slow the anode reaction. The analysis of the research results has showed that the corrosion rate of the steel electrode decreases with increasing the concentration of water-soluble inhibitor in process water. This decrease is the most noticeable when the concentration in the range of 10–50 g/l with an increase in the concentration in the solution of boric acid and triethanolamine to 50 g/l, their protective efficiency varies by 6–14 %. The optimal concentration of the inhibitor in the composition is obtained, which is 10 g/l during corrosion tests of steel plates, the protective efficiency of the solution with a concentration of 10 g/l of the water-soluble inhibitor was more than 70 %. In case of precipitation on the samples, the protective efficiency of the solutions decreased to 20–25 %. When tested in a closed unheated room on steel samples during the year there were no traces of corrosion. Conclusions. The study demonstrates that boric acid and triethanolamine is a watersoluble inhibitor of anodic corrosion. When the concentration of water-soluble inhibitor in process water increases, the corrosion rate of the steel electrode decreases. Optimum concentration of ester of boric acid and triethanolamine in the protective solution should be 10 g/l. For corrosion tests of steel plates, the shielding effectiveness of a solution of water- soluble inhibitor was more than 70 %. In the conditions of direct exposure to atmospheric precipitation on the samples of the protective efficiency of the solutions decreased to 20–25 %. When tested in a closed unheated room on steel samples there were no traces of corrosion during the year. Thus, the ester of boric acid and triethanolamine is effective to protect against atmospheric corrosion in a closed room. it Is recommended to apply it for protecting cars against corrosion at short-term storage on open platforms. The application field of water-soluble inhibitor when agricultural and forestry machines are retained for long-term storage is defined; combine stages of cleaning cars from pollution and preserving their surfaces for protection against corrosion are offered. The article will be useful to specialists in the field of protection of agricultural machinery from corrosion.
Introduction. The processe of harvesting fiber flax is characterized by tough interactions of the work tools of the flax puller and parts of plants. Different principles and design of work tools for taking out seed bolls from the stem, used in flax harvesting machines, have both advantages and disadvantages. Single-drum comb deseeders are the most effective, but the level of damage to the stems caused during the working of these mechanisms is high. The purpose of this work is the experimental substantiation of constructive changes in the comb deseeder, which allows reducing damage to the stems of the flax fiber in the process of combing and improving the quality of the flax material. Materials and Methods. Fields and laboratories studies of flax harvesting and technological tests of flax straw and fiber were carried out according to the existing methods and standard protocols (GOST). The influence of the harvesting combine speed and deseeder type (the drum for the taking flax balls off by the stems’ combing and for the transporting removed balls to hopper) on the yield and quality of the fiber were determined. The fiber flax variety Alexim (cultivated by All Russian Research Institute for Flax Production, Torzhok) was used as a plant object and the harvesting was carried out in the vegetation stage “yellow stem” – “full ripeness”. Results. The classical design of the combing drum with four ridges for deseeding was changed to three ones that means only one of ridges should be in the layer of flax stems during the combing process. That design could decrease damage to the stems when deseeding stems. Instrumental assessment of fiber shows that after the deseeding by the threeridges drum the quality of flax straw was 0.97–1.09 numbers that was by 0.19–0.28 numbers higher than after using four-ridges drums. Conclusions. The obtained data indicate that the reducing of the load on the flax stems has a positive effect on the quality of the fibrous products. The yield of long fiber increases by 1.27–1.54% (abs.), and the fiber quality – by 0.3 numbers.
