Scientific Herald of NULES of Ukraine. Series: Technique and energy of APK → Machinery and Energetics ISSN 2663-1342 (Online), ISSN 2663-1334 (Print) Subject: Results of research on mechanization and energy AIC. Year established: 2010 Founders: National University of Life and Environmental Sciences of Ukraine Published 4 times a year Languages of the publication: Ukrainian, English. Address: Heroyiv Oborony st., 15, Kyiv-03041, Ukraine. Phone: +38 044 527 87 20 Indexed in the following international scientometric databases: Google Scholar AGRIS MIAR BASE ResearchBib Ulrichsweb The main purpose of the journal is the promotion of mechanization and energy AIC. Its main purpose is publishing articles of problem-techniques in production, synthesis and methodical, which highlights research results with statistical data with theoretical and practical significance relevant to agriculture and not previously published.
Національний університет біоресурсів і природокористування України
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Monitoring the technical condition of agricultural machinery for guideline materials for its operation
An important component for ensuring the efficient use and improving the reliability of agricultural machinery is the availability of appropriate regulatory and technical documentation governing the requirements for its technical condition and operation. Serviceability of equipment can be restored during repair, and operability - is maintained during maintenance and in the course of operation on the basis of recommendations provided by the instructions and guiding materials on the use of machines. For timely and effective maintenance and repair of means for preparation and distribution of fodder (MPDF) it is necessary to know: criteria of operability loss; limit and admissible values of parameters of the technical state; process indicators of transition of machinery from operable to non-operable state; regularities of changes in the main properties. The article presents the monitoring of instructions for maintenance and operation of machinery, guiding materials for use from the position of their informativeness on the implementation of reliability requirements. The monitoring was conducted for the analysis of foreign samples of MPDF. Within the framework of the monitoring, grinding-mixing mechanisms (GMM) were analyzed from the position of availability of information about design features, possible failures and malfunctions, main ways of restoration of serviceability. The main provisions, which are determinative for estimation of technical condition of separate parts and working bodies, for improvement of GMM and MPDF reliability as a whole when using guiding materials, have been established. The provisions include: information about indicators of machine reliability; frequency of maintenance and repair of machines, restoration of working parts; information about the labor intensity of maintenance and repair of machines, restoration of working parts; diagrams of assembly-disassembly of mechanisms, restoration of working parts; typical failures and sequence of their elimination; criteria of limiting condition; technologies of restoration of working parts; information on storage requirements
Copyright (c) 2021 Machinery and Energetics
Hidden markov models of technical control of technical condition parameters of self-propelled sprayers
The main indicator used to study the reliability are hidden Markov models of technical control of the technical condition of self-propelled sprayers, which means the probability that the self-propelled sprayer will be operational at any time, except for planned periods during which the use of self-propelled sprayers is expected. Derivation of the analytical expression for hidden Markov models of technical control of the parameters of the technical condition of self-propelled sprayers - a rather time-consuming operation. The complexity increases with the complication of the graph, ie in an effort to take into account more technical conditions, factors that affect the process of technical control of self-propelled sprayers. Therefore, it is advisable to solve the problem of such a plan using a simulation model. Using the Stateflow modeling tool of the Matlab software package, a model has been developed that allows modeling discrete-event models. Model of self-propelled sprayers among Stateflow for estimating the coefficient of readiness during technical control of programs. The results of simulation are the values of hidden Markov models of technical control of the parameters of the technical condition of self-propelled sprayers in various technical control programs, which allows us to draw conclusions about the impact of technical control of self-propelled sprayers on the readiness factor.The probabilities of errors varied from 0 to 1, which is quite justified in cases where the technical control differs only in the place of measurement of the parameter of technical condition, and the means of measurement are the same. The author found that the readiness factor is sensitive to errors of the second kind in this case. Ways of further research are found in the study of other programs of technical control of self-propelled sprayers, in which the readiness factor is sensitive to the probability of errors of the first kind.
Copyright (c) 2022 Machinery and Energetics
Analyticity of complex criteria for evaluation of grain production in agricultural enterprises intensification of engineering management
The article analyzes the analytical nature of complex criteria for assessing grain production in agricultural enterprises by intensifying engineering management. Effective use of combine harvesters and the amount of grain losses during combining in agricultural producers depend on the classic set of organizational, technical, technological factors and the state of engineering and technical service. In order to increase the efficiency of machinery, it is advisable to use operational technology for harvesting cereals, which includes maps and drawings on the following issues: choice of technologies, agronomic requirements, safety, selection and assembly of units, preparation of units, field and detachment preparation, organization of work of units in detachments, transport works, norms of production and fuel consumption, control and estimation of quality of work. It was established that the average daily productivity of the combine during the first 3 years of use was 14.6-16.1 ha; seasonal - 302-314 hectares; grain threshing - 59-161 tons per day and 1280-1440 tons - per season. To obtain the required productivity and quality of threshing, it is necessary to constantly monitor the size of the gap between the drum and the drum. To increase the productivity of grain unloading, it is advisable to carry out while moving without stopping the combine, because when threshing 60 tons per day, approximately 1.6 hours of working time are lost.It was found that the existing harvesting system does not take into account the dynamics of grain and straw ripening and their purpose according to the scheme: entry into the process (first phase), the main part of the above average (second phase) and exit from the process (third phase), inefficient due to low survivability of the collection system in organizations, regions and oblasts in the first and third phases. Analysis of numerical indicators shows that when all crops are harvested, the pace of the process in the first phase increases slowly, in the second - faster, and at the output decreases to a minimum. In the first phase, the average rate for rye, barley, oats and wheat reaches 0.25, respectively; 0.21; 0.30 and 0.26 cycle times. The duration of harvesting each crop with a rate above average is less than half the duration of the cycle, and with a rate below average - more than half. The general conclusion from the given data comes down to the fact that 26-33% of the harvest in farms can be obtained by using resource-saving technologies. Analysis and synthesis of the regularity of the harvesting process shows that during one day the maximum rate reached 18.2-34.9% of the total, which exceeded the average rate by 3.58 times.
Algorithm for optimization of production processes and passenger transportation operations
Research of transport processes are closely related to the economic and operational performance of road transport. When planning road transport, the most important factor is the cost of transport services. It is known that improper organization of the vehicles work taking into account the type, size, modes of vehicle stock operation of, quantitative composition, qualifications and responsibilities of personnel, along with other organizational measures leads to unjustified costs. In general, this reduces the attractiveness of the business to its owner, as well as reducing motivation for staff. Therefore, research related to improving the efficiency of vehicles by reducing costs is appropriate and relevant. The article presents the results of research on the planning of transport processes in the performance of public passenger transport on urban and suburban routes. The proposed method is aimed at optimizing the number of vehicle stock and its passenger capacity depending on the capacity of passenger traffic and the recommended traffic interval, and also allows you to calculate economic and financial indicators based on the optimization model. The article presents the results of research to determine the transport mobility of cities and suburbs residents. On the basis of research data of the population survey a number of qualitative indicators of passenger transport work important from the point of its user’s view is established. Also, according to the results of research, the probability of increasing passenger traffic due to the redistribution of the population (potential user of public transport), who uses individual transport and taxis. Therefore, the main purpose of the research is a multi-criteria task, which is to ensure adequate forecasting of fixed and variable costs in the performance of passenger road transport on public transport. As well as obtaining a constant and projected profit due to the algorithm for optimizing the work of vehicle stock, the work of driving crews, the elimination of unproductive costs.
optimization of business processes in motor transport
rational solutions in the field of passenger transport
Mathematical modeling soil tilling unit in the system "soil-aggregate-energy means" for Strip-Till technology soil treatment
The agro-industrial complex of Ukraine is a branch of the national economy designed to ensure the production of sufficient food for the population at high quality. The basis of agricultural production is agriculture, the main subject of which is land. Today, agriculture in the country is experiencing a very serious problem associated with the rapid decline in potential soil fertility. The main material wealth of the country is fertile soils - chernozems, which make up a significant part of the country. Chernozems are extremely fertile and rich in organic matter such as humus, which creates agronomic conditions for growing a wide range of crops of plant origin. In recent years, a new direction in the formation of agriculture is emerging in the world, in fact, it is a new strategy based on the use of modern innovative tillage technologies and the development of combined units for their implementation. With such the latest trends in agriculture in the world, appropriate changes should be made in Ukraine, in particular the introduction of soil-saving and resource-saving tillage technologies. The work is devoted to the development of a mathematical model of the process of operation of the tillage unit for tillage technology as Strip-till. In order to reduce energy consumption for tillage, preserve the main indicator of soil fertility - humus and rational aggregation of energy products with tillage units, promising ways to reduce based on mathematical modeling and analysis of relationships between elements. The mathematical model of the process of operation of the tillage unit for the Strip-till technology in the technological system "Soil-unit-energy means" and the analysis of its intra-system dependences and connections are developed and substantiated.
Hardness – volumetric characteristic of material
Producing details for different purposes is guided by the conditions of their work and, therefore, attention is paid to such characteristics as strength, viscosity and hardness. Only the method of determining the hardness of the material allows you to conduct research without destroying the detail in addition to physical methods. This takes into account the fact that the other properties are indirectly related to the hardness parameter. The main disadvantage of all modern methods of the material hardness measurement is the inconsistency of the practical content of the units of measurement of the studied parameter to the theoretical essence of hardness - as a physical quantity that characterizes the properties of a rigid body. The units of all hardness measurement methods, depending on the scale factor, are usually compared by converting their values to such generally accepted methods as Brinell, Rockwell, or Vickers. The conversion of the hardness values obtained by different methods should be used very carefully and preferably for a preliminary assessment of the relative changes in material properties. When applying these methods, the units of measurement are the ratio between the load on the indenter, a given standardized shape and the area or depth of the imprint. However, based on the physical content of a property such as hardness, it is necessary to determine the relationship between the load on the indenter and the volume of the displaced material. This work aims to establish a theoretical basis for the digital characteristics of units of hardness obtained by different measurement methods. To provide the physical meaning of the determining of hardness, the dependence of the volume of the displaced material on the applied load was determined. The comparison of these values made it possible to really determine the relationship between the units of different methods not based on practical comparisons, but by summing up the theoretical basis. The obtained results indicate a sufficiently high correlation between the results obtained with different hardness measurement methods.
Experimental efficiency studies use of unmanned aircraft in cultivation of agricultural cultures
Modern agricultural production is aimed at obtaining the maximum yield when growing crop products. Genetics creates varieties and hybrids that maximize their biological potential in accordance with growing conditions. However, the urgent task is to provide technology, namely the needs of plants in the appropriate phases of growth and development in the shortest possible time. Current developments, including those for agricultural production, have flooded the market for digital technologies and mechanization tools. Effective agroengineering requires a modern base of complex applied research on the effectiveness of using the latest developments in modern production conditions. It should be noted that each development will show different efficiency, namely different quality indicators in different production conditions. The effectiveness of field research using an unmanned aerial vehicle (UAV) XAG XPlanet for four fans was carried out in the Sumy region on the research fields of the Sumy National Agrarian University. The uniqueness of the research was that a method was developed with the involvement of specialists in agroengineering and agronomic fields and specialists in the field of physics to determine the degree of coverage of a sheet with a working solution precisely when it is "crushed" by the UAV blades; the technique of digitalization of markers was used by determining the color of the working solution, taking into account the change in its brightness depending on the time interval from application to research; clipping dark highlights when scanning markers. The studies were carried out at different flight heights: 3, 4 and 5 m above the plant level and taking into account different flight speeds: 6, 8 and 10 m s-1. The corresponding data were due to different plant heights, relief and configuration of the field, the location of the wires of electrical networks. The developed methodology and the conducted field studies made it possible to prepare real recommendations for modern agricultural producers in the direction of the efficiency of using UAV for introducing working solutions and choosing effective operating modes.
Technologicity of maintenance of combine harvesters systems during storage
The solution of universal, global problems of energy and resource conservation in both mechanical engineering and agro-industrial complex are inextricably linked with the solution of issues of protection of machinery from corrosion. Modern agricultural machinery, and self-propelled combine harvesters in particular, are operated periodically for one or two seasons a year. Most combine harvesters are stored in the open areas of agro-industrial enterprises, and it is exposed to aggressive environmental influences (fluctuations in temperature, humidity, wind, solar radiation, dust and others). The main type of environmental impact on the equipment is atmospheric corrosion and the corrosion wear caused by materials, parts and components, which leads to its premature failure. Thus, the fatigue strength of steel products when stored for 12 months in the open reduces by 28–58%. To ensure temporary corrosion protection of combine harvesters, a large number of conservation and working-conservation oils are used. However, the unresolved number of issues of theoretical and practical nature leads to the unjustified use of protective equipment, which either does not provide the required duration of storage of equipment, or increase the cost of its preservation. Standardized methods of testing anti-corrosion lubricants in the vast majority have a number of disadvantages, the most important of which is that the evaluation of protective properties is carried out in units that do not allow to estimate their service life, but only show the corrosion of the metal.
Improving the quality of agricultural seed treatment with the combination of combined treatment
The article presents the results of research on the process of seed treatment of agricultural crops in order to identify the causes of imperfections in the work process when using liquid preparations and proposes quality improvement through combined seed treatment. The essence of the developed modification of the seed treatment is its combined treatment - after treatment with liquid pesticides by one working body, treatment with ultraviolet and ozone is added for drying, disinfection and stimulation of seeds inside the treatment chamber in one pass. The final part of the article presents a diagram of the working process of the disinfectant and the conclusions and prospects for its use.
Synthesis of energy-saving transport-technological systems with screw working bodies
The purpose of research is the synthesis and presentation of new designs of energy-saving transport and technological systems. The object of research is the processes of transportation of bulk materials by transport and technological systems with screw working bodies. The subject of research is the design of energy-saving transport and technological systems with screw working bodies and their parameters. The method of generation of constructions of energy-saving transport-technological systems with screw working bodies by synthesis of hierarchical groups by means of morphological analysis is offered in the work. The model of the mechanical system "screw conveyor" with grouping of constructive elements on hierarchical groups and assignment to the first group of mechanisms of transportation of freight, screw working bodies and mechanisms of transfer of the twisting is developed. Results. A method of structuring the structures of energy-saving transport and technological systems with helical working bodies and a method of their improvement based on the study of the properties of the elements of their structure in accordance with the theory of synthesis of hierarchical groups using morphological analysis.
Movement of particle on inner surface with preset meridian, which rotates around vertical axis
The article considers the relative movement of a particle on a surface which rotates around a vertical axis. The meridian of the surface is the branch of the parabola, offset from the axis of symmetry by a given value. Differential equations of relative displacement of a particle are compiled and solved by numerical methods. The trajectories of the particle and the graphs of velocity change are constructed. The regularity of the particle's movement when it rises on the surface is clarified.
Regression models of technological processes post-harvesting grain
The paper presents the regressive models of technological processes of post-harvest grain processing (PHGP). In the technological model of the functioning of the EMP system, there are interrelated indicators of the quality of equipment operation with the probability of being at acceptable levels of operating conditions, the technological state of the system and internal obstacles. Presented is a technological model of the PHGP system and regressive models of the functioning of grain cleaning machines in the form of one and three subsystems. The developed technological model of the functioning of the technical equipment of the PHGP shows the need to determine the technological tolerances of the performance indicators of the grain cleaning machine in the conditions of their normal functioning, should be taken into account when developing methods for calculating the parameters of the technical equipment process of the PHGP. Regressive models of technological processes of the PHGP in a normalized form is the basis for obtaining mathematical models for predicting the quality indicators of the functioning of machines and units in field conditions and for carrying out a machine experiment by the method of simulation.
Food supply transport and logistics system organizations
The logistics system for agricultural products distribution in the current global economy is the main topic for discussion in society and in the scientific literature, and food security is closely linked to the concept of sustainable economic development. The article considers a number of factors influencing the efficiency of logistics systems for agricultural products distribution in the global economy and analyzes the problems that arise in the management of business processes in food supply chains. It is determined that in the agri-food chain the decisive factors for creating and maintaining competitive advantages are access to the best buyer at the appropriate level of quality, with the required shelf life and proper passage through the supply chain. In the context of globalization, the competitive advantages of logistics services, based only on price and consumer properties, lose their leading importance, and in the first place are flexibility, limited lead time, reliable and high-quality supplies, choice, and so on. The complexity of the organization of transport and logistics systems for the supply of perishable food products is due to, on the one hand, the participation of a large number of links in the chain, and, on the other hand, the features of perishable goods.
Increased biogas output during fermentation of manure of cattle with winemaking waste in biogas plants
The aim of the work is to increase biogas output and generation of electricity in biogas plants due to the joint fermentation of cattle manure with winemaking waste. To achieve this goal, the following tasks were solved: the biogas yield from cattle manure with winemaking waste was determined during periodic loading of the digester; on the basis of the obtained experimental data, a mathematical model was calibrated to estimate the biogas yield during fermentation of cattle manure with the addition of winemaking waste. As a result of the studies, it was found that when manure is fermented with part of the water replaced in the substrate 2% of the winemaking waste, the fermentation dynamics in the substrate are similar to the fermentation of pure cattle manure. Biogas obtained by fermentation of manure with the addition of 2%, 6.5% and 13% of wastewater from wine production instead of water in the first day of fermentation either did not burn at all or burned poorly. The addition of winemaking waste to a substrate based on manure in an amount of 13% allows increasing the maximum biogas yield by a third to 1,372 l/(hr×kg dry organic matter). The significance of the research results lies in the fact that the use of winemaking waste as a substrate will allow a third increase in biogas output and power generation, and a reduction in the payback period of a 4,4 MW biogas plant using the green tariff to 6,5 years.
Restoration resource of working bodies of soil treatment machines by applying wear-resistant coatings
Intensive soil compaction, which is caused by the use of modern powerful tractors with high weight and the presence of higher working speeds, and as a result reduces the service life of tillage equipment. Difficult weather conditions cause an increase in the load on the working bodies of tillage machines, with the wear of the surfaces of the working bodies of agricultural units. The article considers the problem of increasing the resource of the working bodies of tillage machines due to the application of wear-resistant coatings. The types of wear and the influence of abrasive materials on the working bodies of tillage machines are analyzed. Determined optimal materials and methods to increase the wear resistance of the working bodies of tillage machines. Features of formation of a metallization covering which is reflected in its structure and character of defects which can differ in the sizes, density, morphology and orientation are considered. The dependence of the properties of coatings on the material doping system is substantiated. Equipment and materials for coating are given. Taking into account the received information, conclusions are made and the analysis of technology of drawing wear-resistant coverings for increase of a resource of working bodies of tillage machines is carried out.
Theoretical studies of air losses of air heat exchanger of indirect-evaporative type of livestock rooms
. Air heat exchangers of the side-evaporating type based on the Maisotsenko cycle have a higher transformation coefficient, so it is advisable to use them for cooling livestock premises. However, one of the tasks of increasing the efficiency of such heat exchangers is to optimize its parameters by reducing pneumatic losses. Therefore, the aim of the research is to determine the pneumatic losses of the heat-evaporating type heat exchanger and to establish the regularity of the change of pressure and power losses required for pumping air through it from its design and technological parameters. As a result of analytical researches of pressure losses of the air heat exchanger of side-evaporating type dependences of losses of pressure and power on quantity of channels, the area of section of channels, average speed of air in channels provided their equality and their form (square, equilateral triangle, circle). It is established that the most effective form of channels in the aspect of pneumatic losses (reduction of pressure losses by 23%) have channels in the form of an equilateral triangle.
Technological essence of carbon production sorbents based on vegetable raw materials and their economic efficiency
It is shown that due to the rapid increase in the number of vehicles, the use of fuels and lubricants is increasing, which, despite all measures and precautions, pollute the environment with harmful and toxic products through spills and spills. It has been studied how oil products and their decomposition products that enter the environment pollute the soil and water. The efficiency of soil and water treatment depends on the method, technology, method, tools and techniques. The method of sorption (absorption) is becoming especially popular and widespread in the purification of soils and water from pollution. It is analyzed how the method of sorption, at relatively low cost, provides effective purification of soil and water from petroleum products. The technologies of obtaining carbon sorbents by the method of carbonization from by-products of plant origin (sawdust, straw, leaves), the volumes of which for the synthesis of carbon sorbents are practically not limited, are substantiated. The essence of the process of carbonization of carbon sorbents on the basis of vegetable raw materials is highlighted. Physical, chemical, structural, sorption and absorption characteristics of plant raw materials and carbon sorbents obtained from it are presented. The ecological, economic advantages and efficiency of carbon sorbents of vegetable origin for purification from oil products, in comparison with other purification methods are revealed.
Chemical composition influence on element segregation and properties of steel strip manufactured by strip casting route
The article presents the results of the chemical composition influence on element segregation and properties of steel strip manufactured by strip casting route. It is shown that in the transition from the slab production with a thickness of 220 mm to slabs with a thickness of 1.2 mm, the thickness of the segregated diffusion layer in the case of the continuous strip casting process is 4.1 - 12.4 times less than in the case of traditional continuous casting. The carbon, nitrogen, copper, tin, phosphorus and sulfur segregation percentage in the continuous strip casting process is 1.7 - 5.1 times less than in traditional continuous casting. A method is proposed for calculating the element segregation based on the equality of the segregation level in traditional and strip continuous casting. It has been established that the content of elements in steels during two-roll continuous casting can be increased for impurities such as S, O, N, P, H from a minimum of 3 for P to a maximum of 497% for S. For residual elements such as Pb, Bi, Sn, Cu, Sb, Zn, As minimum increase from 1.1 for Zn to maximum 401% for Pb. The content of such alloying elements as B, Se, Al, Te, Ca, Mg, Ce, C, La, Nb, Ti, Mn, Ni, Si can be increased from a minimum of 1.1 for Si and Mn to a maximum of 675% for B. The time and rate of cooling of a 20-ton coil of steel strip are calculated, which are, respectively, 13.7 hours and 0.0051 oC/s. Such cooling conditions create the prerequisites for the precipitation of chromium carbides and an increase in the tendency of steel to intergranular corrosion. It was found that for eliminate this problem, it is necessary to increase the cooling time with water after rolling to a strip temperature from 300 to 400 oC.
Mathematical modeling of stability of mechanical system of discator
The study is devoted to the construction of mathematical models of the stability of the mechanical system of the disc harrow for surface tillage. The objects of scientific research are selected disk working bodies on elastic racks and a support-rolling roller. The article presents the results of mathematical modeling of the stability of the mechanical system of the disc with the attachment of the working bodies on the elastic racks and the support-rolling roller. As a result of analytical researches the system of differential equations of oscillations of a frame and working bodies of the disc harrow during performance of technological process taking into account changes of physical and mechanical properties of soil is made. According to the developed algorithm in the Mathematica software package the expression in the form of regression equation for determining the degree of asymptotic stability at the angle of oscillation of the frame φ of the working bodies of the disc depending on its design and technological parameters, namely, the step of the spiral of the first and second rows aI aII, the distance between the elastic struts Δx, diameter d, angles of attack α and the inclination γ of the disk working body, the speed of its movement V when performing the process.
Experimental studies of the motion modes of the main boom and jib of loader crane
In order to increase the productivity and reliability of a hydraulic-powered loader crane, according to the normative-technical documentation regulating the safe operation of multi-link cranes, it is allowed to combine movements with the simultaneous movement of several links of the boom system. As a result, the paper considers a technique for conducting experimental studies in the plane of changing the boom system of a loader crane with a load. Experimental studies were carried out under the condition of simultaneous angular movement of the main boom and jib. To carry out experimental studies, an experimental installation of a hydraulic-driven loader crane was designed and manufactured. Measuring and recording equipment has been selected and adjusted. In the framework of experimental studies of the dynamics of movement of the boom system of a loader crane with a load, a control system for drive mechanisms has been developed, which makes it possible to realize the optimal modes of movement of the links of the boom system. As a result, experimental studies were carried out under the condition of simultaneous movement of the main boom and jib with a load at the end of the boom system. A package of data on real and optimal modes of movement of the links of the boom system of the loader crane was received. The processed data are presented in graphical form and a comparative analysis with real and optimal modes of movement is carried out. The developed method of experimental research has made it possible to determine the effect of the simultaneous movement of the boom and jib on the oscillations of the load, and the effect of the oscillations of the load on the dynamic loads arising in the boom system and the drive mechanisms of the loader crane.
Thickness influence on element segregation in continuously cast steel slabs
The article presents the results of a study of the effect of slab thickness on the element segregation of during continuous casting of billets. The process of accumulation of elements on the surface of dendrites during crystallization of steel slabs for various thicknesses is considered. The theoretical dependence of the process of accumulation of elements on the dendrite surface during the crystallization of steel slabs for various thicknesses has been established. It is shown that the efficiency of accumulation of elements on the dendrite surface depends significantly from the crystallization and cooling rate of the slab. The established dependence makes it possible to determine the permissible increased element content in strips, which is equivalent to their content in thick slabs during continuous casting of billets. The element segregation searching shows that at pouring of thin steel strips, an increasing of the element content is possible compared to continuous casting of thick slabs with an identical level of segregation. The elements are arranged as possible to maximize the impurities content in AISI 1006 carbon steel in the following decreasing sequence: S, O, N, P, H. Another sequence is observed for stainless steel AISI 304: O, S, P, H, N. The following sequences are observed in the case of residual elements: - for steel AISI 1006 - Pb, Bi, Sn, As, Zn, Sb, Cu; - for steel AISI 304 - Cu, Sb, Sn, Bi, Pb, As, Zn. The sequences are as follows for the alloying elements: - for steel AISI 1006 - B, Se, Al, Te, Ca, Mg, Ce, C, La, Nb, Ti, Mn, Ni, Si, Cr; - for steel AISI 304 - Ca, Te, Al, Ti, Mg, C, La, Ce, Nb, Se, V, B, Si, Cr, Mn.
Analysis of safety regulations for mechanized spraying of agricultural crops
Today there is a tendency of intensive growth of chemical plant protection with pesticides, which are potentially dangerous for the environment and humans. Accordingly, the risks of poisoning and occupational diseases associated with the use of pesticides in agricultural production are increasing. In Ukraine, a number of legislative and safety regulations have been adopted that regulate the legal relations related to the use of pesticides in agricultural production. State sanitary rules of DSP 8.8.1.2.001-98 are the main normative document that regulates the requirements for transportation, storage and use of pesticides in production. Standards have been developed and approved for more than a quarter of a century, are outdated and do not take into account the peculiarities of new technologies. Therefore, taking into account the current requirements for hygienic regulation and obtaining new data on the toxicological properties of pesticides, there is a growing need to harmonize the domestic regulations with the requirements of the European Community. Some of the current regulations need to be revised and modernized. Recommendations for the use of personal protective equipment for spraying operations were analyzed in accordance with DSP 8.8.1.2.001-98 and the safety data sheet of the fungicide of Akanto® Plus manufactured by DuPont International Operations CH-1218 Le Grand-Saconnex/GE Switzerland, developed in accordance with Regulation (EU) №1907/2006 with changes. The analysis of safety equipment, namely eye and respiratory protection, showed that the use of the recommendations of DSP 8.8.1.2.001-98 for employees of chemical protection operations by spraying is contradictory, which can create dangerous working conditions. For some types of work, these are too high requirements that are difficult to meet in real field work conditions. Therefore, in Ukraine, the need to revise existing regulations and harmonize them with European standards has arisen regarding the safety requirements for transportation, storage and use of pesticides.
Investigation of particle movement on rotary spherical segment
The article considers the relative movement of a particle along a spherical segment that rotates around a vertical axis. Differential equations of relative displacement of a particle have been compiled and solved by numerical methods. The relative and absolute particle trajectories and the graphs of changes in relative and absolute velocities were constructed. The regularity of the particle's movement when it rises on the surface is clarified.
Statistical analysis of functioning of repair service of Ukraine
The efficiency of agriculture and its individual sectors largely depends on the provision of technical means for technological processes of production. Reducing the number of agricultural machinery and equipment, reducing the quality indicators of their use leads to a reduction in the volume of production of the agrarian industry. In connection with the constant development of scientific and technological progress, the study of the market of agricultural machinery and repair costs for loss of performance requires new research and modern scientific approaches. In recent years, the formation of directions to ensure the reliability of agricultural machinery in the system of innovation processes based on the analysis of repair costs remains relevant. The paper presents the results of research on the dynamics of expenditures on repair of agricultural machinery in the period 2015-2019. From the information sources of the State Statistics Service of Ukraine it was found that in 2019 the costs of repair of agricultural equipment amounted to 2127.5 million UAH. The maximum expenses for repair of agricultural equipment in 2019 in Ukraine among regions was 279.55 million UAH in Kyiv region. Expenditures of funds for repair of agricultural equipment in Kyiv region have a dispersion in the range from 1,726 thousand UAH to 44866.29 thousand UAH. During the processing of statistical data, the agricultural enterprises of the region were conditionally divided into three gradations: І grade – 42 enterprises; ІІ grade – 101 enterprises; ІІІ grade – 43 enterprises. Prospective directions of research are the analysis and synthesis of costs for repair of agricultural machinery, improvement of maintenance and repair strategies. The methods of research of agricultural machinery repair costs should be based on the results of statistical analysis, take into account the state of machines in operation, the repair strategies adopted, the results of technical condition monitoring.
Study of methods for neutralizing biodiesel with aqueous solution of citric acid
The production of methyl esters of fatty acids, also called biodiesel, by traditional technology occurs in the presence of an alkaline homogeneous catalyst, which does not react, but only accelerates it, remaining in the manufactured methyl ester of fatty acids and causing engine corrosion. Purification of methyl esters of fatty acids from a homogeneous catalyst must be preceded by its neutralization. An aqueous solution of inorganic (hydrochloric, sulfuric, phosphoric, etc.) and organic (acetic, citric) acids is used for this purpose. The aim of the study is to determine the establishment of optimal and rational parameters for the neutralization of methyl esters of fatty acids. Studies of the effectiveness of neutralization of methyl esters of fatty acids were performed by mixing it with an aqueous solution of citric acid (volumetric method) and by spraying an aqueous solution of citric acid over a layer of methyl ester of fatty acids (aerosol method). Investigations of the influence of the stirrer parameters on the alkalinity of the neutralized methyl ester of fatty acids were performed at temperatures of 20°C, 40°C, 60°C and 80°C and stirrer shaft speeds of 200, 350, 500 and 650 rpm. The stirring time was 5 minutes The study of the effect of nebulizer parameters on the alkalinity of fatty acid methyl ester was performed by spraying 6 ml of an aqueous solution of 1% citric acid per 100 ml of fatty acid methyl ester through a centrifugal full-cone spray "Dis and Core". The spraying time was 1.5-3 s at a pressure of 0.15-0.25 at. It is experimentally established that the neutralization of biodiesel should be carried out in a three-dimensional way at a temperature of 40°C and a rational speed of the stirrer shaft 240-410 rpm/min., While the optimal speed of the stirrer shaft is 323 rpm/min.
Quality improvement of practical training on the subject "the road traffic regulations"
In recent decades, the world has seen a rapid increase in the number of vehicles and an increase in traffic, which leads to an increase in the number of road accidents and their negative consequences. For example, according to the World Health Organization (WHO), road traffic injuries are one of the biggest health problems today. Road accidents are projected to be one of the top five causes of death in the world in 2030. In Ukraine, the level of deaths and injuries due to road accidents is one of the highest in Europe, and the level of road safety remains extremely low, as repeatedly pointed out in their reports by experts from the WHO, the World Bank and other international institutions. More than 26 % of those killed and 15 % injured in road accidents in 2019 are pedestrians (1,414 people died and 8,455 people were injured). In 2019 alone, 329 children under the age of 18 died on the roads of Ukraine and 7,906 children were injured. Accidents in Ukraine are the first most common cause of death for young people aged 15 to 24 and the second most common cause of death for children aged 5 to 14. Thus, in 2019, compared to 2018, the number of road accidents increased by 7 %, as well as the number of dead and injured persons by 4.2 % and 6.3 %, respectively. Ukraine is also one of the leaders among EU countries in terms of specific indicators of accidents and consequences of road accidents. Thus on average in the EU member states (according to 2017 data) there are 5 fatalities in road accidents per 100 thousand populations, while in Ukraine this figure is (according to 2017 data) 12.5 people, respectively, which is more than the European average. 150 %. It is also important to note that in the absence of quality data collection on injuries and deaths due to road accidents, these indicators may not reflect the present figures. A significant number of road accidents that occurred in Ukraine during 2017-2019, as well as people injured in them, affect the economy and health care of Ukraine. Studies conducted by many countries establish a general rule that every death costs about 70 gross domestic products per person, and every serious injury to a person amounts to about 17 gross domestic products per person. If we apply this rule to the indicators given above, it becomes clear that the cost estimate of socio-economic losses of Ukraine (excluding material costs associated with property damage and reduced productivity) from these accidents and their consequences in 2019 alone is about 4.79 billion US dollars (3.18 % of Ukraine's gross domestic product). The main reasons for this situation are the insufficient level of road safety; improper maintenance of vehicles; low level of discipline of road users; inconsistency of the state of the road network with the level of traffic intensity; insufficient introduction of the latest technologies and technical means of traffic organization; low level of training of future drivers. The article considers the problems of the educational process related to improving the quality of practical training of students in the discipline "Traffic Rules" and suggests effective ways to solve them by differentiating approaches to managing the cognitive activity of students.
the conceptual and logical sphere of thinking.
Movement of soil particles on surface of developable helicoid with horizontal axis of rotation with given angle of attack
The interaction of the screw tillage body with soil particles is considered in the article. Due to its very wide application in engineering, the term "helical surface" is usually understood to mean the surface of a helical conoid or auger. The surface of the deployable helicoid, which is also linear, but significantly different from the auger, is considered in the work. The difference is not only in the geometric shape, but also in the manufacturing technology. If the auger is made by stamping or rolling a strip with significant deformations of the workpiece, then the deployable helicoid can be made by simple bending with a minimum of plastic deformation. From the point of view of the theory at zero thickness of preparation plastic deformations at its bending in general would be absent. The working body for tillage consists of a strip of developable screw surface, in which the outer edge is pointed and acts as a blade, and the inner is rigidly attached to the lattice cylinder. The difference between the radius of the screw line of the blade and the cylinder determines the depth of processing. The lattice cylinder prevents clogging of interturn space and at the same time carries out additional function of a roller. The body works like a disk tool that is the profile of the treated field has ridges and depressions. At the time of contact of the blade with the surface of the field there are angles similar to the angles of attack and roll for disk guns. The design parameters that provide these angles can be calculated based on the analytical description of the surface. The section, that is the drum with the turn of the screw working surface, is located so that its axis is a certain angle with the direction of movement of the unit. This cause the angle of attack and reaction forces that cause the drum to rotate with the surface. Based on the speed of the unit and taking into account the angle of attack, we can find the angular velocity of the section. Next, a differential equation of motion of the particle is formed after its entry on the rotating surface. The differential equation is painted in projections on three axes of a fixed coordinate system. It includes three unknown dependencies: two variables that describe the trajectory of the particle sliding on the surface and the reaction force of the surface. The system is solved by numerical methods. The trajectories of relative and absolute motion of a particle and graphs of changes in its relative and absolute velocities are constructed.
Research of gravity separator of rapesee
Rapeseed contains up to 40…49% oil, 21…33% protein, 6…7% fiber. Rapeseed oil is used in the production of fats and margarine, as well as in the metallurgical, paint, soap, textile industries. Insufficient study of the process of purification of rapeseed seeds constrains its prevalence in Ukraine. Recently, the purification of rapeseed from difficult-to-separate weeds and impurities is carried out by hitting the reflective surface using the elastic properties of the seeds. The cleaning machines used a single blow and have a low separation quality. The construction of the gravitational multilevel separator of rapeseed is considered in the work and its parameters with the possibility of repeated blows of heap particles with reflective surfaces are substantiated. Based on the analysis of experimental studies of the elastic characteristics of rapeseed and impurities, the rational height of the fall of the seed heap, which is in the range of 0,2…0,4 m, was determined. Theoretical calculations allowed to determine the flight lengths of particles with repeated rebounds from the impact surface and made it possible to justify the dimensions of the impact deck in the transverse direction 0,2 m and – 1,5 m in the longitudinal. As a result of the production tests it was found that the most acceptable initial speed is Vo= 2 m/s, and the angle of inclination of the deck α = 300. The production conditions of the separator proved that when the rapeseed seed heap is clogged up to 15%, the yield of the purified fraction is 68% of the seeds of the first class.
Technical and insurance evaluation of carbon sorbents on basis of vegetable raw materials for purification of petroleum products
The use of fuels and lubricants in Ukraine is rising, primarily due to a rapid growth in the number of vehicles. This results in an increase in harmful emissions, flowout and spills of petroleum products, which negatively affects the ecological condition of the environment. It is revealed that oil products used in the national economy, getting into the soil and aquatic environment pollute them. Soil and water purification depends on the choice of methods, technologies and techniques. The method of sorption (absorption). Sorption, at relatively low cost, is able to provide complete purification from petrochemicals. The efficiency of carbon sorbents obtained by carbonization from secondary products of plant origin is substantiated. Raw materials for production of carbon sorbents can be sawdust, shavings, straw, stems, chaff, leaves. Their quantity for the synthesis of carbon sorbents is practically unlimited. The essence of the process of obtaining carbon sorbents on the basis of plant raw materials is highlighted. The physicochemical and structural sorption characteristics of plant raw materials and carbon sorbents obtained from it are presented. Advantages of carbon sorbents for purification from oil products in comparison with other purification methods are revealed.
Estimation of efficiency of application of lubricants with fullerene compositions during operation in main cycle of trucks
The paper deals with the assessment of fuel efficiency of the car at operation with use of lubricants (motor and transmission oils) with fullerene compositions on the main driving cycle. Fullerene compositions were added to the engine and transmission oil at a concentration of 10% of the mass. The guiding document that defines the procedure for testing vehicles for fuel efficiency is National State Standard GOST 20306. Tests on the main cycle were carried out on a truck ZIL-5301 "Bichok" having a total mileage from the beginning of operation of 20 thousand km. The car is equipped with a diesel engine D 245.12 with a turbocharged capacity of 73 kW and a specific fuel consumption q = 245 g/kWh. The tests were performed on a ring road with a straight section. Before the start of the tests all units of the car were warmed up by a run on a ring road not less than 50 km long at a 2/3 maximum speed. The tests were performed on the main cycle at an ambient temperature of +20°С (summer period of operation) and at an ambient temperature of -5°С (winter period of operation). Control races began in the car, which used lubricants according to the operating instructions. In the engine lubrication system engine oil M-10G2к (API CC, SAE 40), transmission units - transmission oil TAD-17i (API GL-5, SAE 85W90). Control races were repeated three times. At the same time, the arrival time was recorded with the help of a timer and the volumetric fuel consumption with the help of a flow meter in cm3. It is established that when operating a car on main roads with asphalt pavement in the summer of use of fullerene composition in both engine and transmission oils, reduces the fuel consumption of the car on 15.43...18.34%. The value of 18.34% corresponds to the mileage of the car without cargo (m = 0), and the value of 15.43% mileage with cargo (m = 3000 kg). The coefficient of variation of the measured value of fuel consumption was 0.031...0.044. This allows us to conclude that the measurement error lies within 3.1...4.4%. The operating the car on the main roads with an asphalt covering in the winter of operation of application of fullerene composition (concentration 10% of the mass) simultaneously in engine oil and transmission oil reduces fuel consumption by 14.25...16.14%. The value of 16.14% corresponds to the mileage of the car without cargo (m = 0), and the value of 14.25% mileage with cargo (m = 3000 kg). The coefficient of variation of the measured value of fuel consumption was 0.046...0.035. This allows us to conclude that the measurement error lies within 4.6...3.5%.