To assess the effectiveness of corn cultivation technology based on the minimum tillage technology (Mini-till) and organic fertilizers, and compare it with the conventional technology including mouldboard ploughing, the authors conducted field studies in two farms of the Novokubansk district of the Krasnodar region. They analyzed economic efficiency indicators of seeders, the machine-tractor fleet, and the technology applied as a whole. The comparative analysis of economic indicators of an Optima TFmaxi direct seeder coupled with a John Deere 8310RT tractor used in the Mini-till technology and seeders used in the conventional technology have shown that using a direct seeder for seeding corn reduces mechanized work input by 0.15 man-h/ha (43%) and fuel consumption by 0.2 kg/ha (7%) as contrasted to the conventional one. However, specific operating costs are 3 times higher. The comparative analysis of the use of machinery and tractors in both technologies has shown that the Mini-till technology, as compared with the conventional one, uses less machinery (by 18 units, or 62%). But at the same time, the Mini-till technology uses 100% imported machinery, while the conventional one - only 24%. It has been established that the cost of resources for soil tillage in the Mini-till technology decreased as compared to the conventional one: mechanized work input - by 0.58 man-h/ha (46%), fuel consumption - by 9.1 kg/ha (18%), and specific operating costs - by 1227 rub./ha (17%). While using the Mini-till technology, the farmers recorded a grain corn yield of 10 t/ha, which is higher than that gathered with the conventional technology by 3 t/ha (43%). The obtained scientific and practical results prove the use of the Mini-till technology for economically sustainable agricultural enterprises of all ownership forms in the Southern Federal District of Russia.

Intensive agricultural production is impossible without the use of plant protection products that contribute to high yields. Agricultural producers highly evaluate the chemical method of plant protection based on the wide use of sprayers as a more efficient and productive one. The analysis of modern sprayers has shown that their design is subject to the dominating trend of increasing productivity, a working width and a tank capacity, improving the quality of work, improving the main components and equipment, using various automation tools to reduce the environmental impact. There are also some long-term trends in the development of autonomous robotic machines and unmanned aerial vehicles, combined into a single intelligent precision farming system. It is noted that the following operating parameters of the sprayer greatly influence the quality indicators of the chemical treatment of plants: the unit speed; the rod installation height and its stability during operation; pressure in the working fluid supply system and nozzle operation parameters (the diameter of droplets formed, the degree of wear and clogging). Environmental parameters also have a significant impact: relative humidity and air temperature, wind speed and the amount of precipitation. To ensure high quality, efficiency, and environmental safety of chemical plant protection, it is necessary to improve the technical means of plant protection through optimizing the main operating parameters, introducing advanced technical solutions aimed at increasing the technological process efficiency; introducing automation and robotization systems of technical means used for plant protection; designing autonomous robotic machines and unmanned aerial vehicles, combined into a single intelligent system of precision farming.

The development of organic agricultural production in Russia is hampered by the lack of the necessary organic fertilizers as modern technological lines processing peat, brown coal, sapropel, and biohumus are still unavailable. Because of the need for such technological lines, a mathematical model has been developed to describe the hydromechanical and mechanical processes, enabling operators to select the operating mode parameters of the technological line. For the first time, the proposed model can be used to form a suspension with the required fineness in a hydromechanical cleaner and reactor. The authors propose a technique for assembling technological lines based on modular equipment to process organic raw materials that ensures the industrial productivity and quality of humic fertilizers. It is shown that the presented mathematical model fully complies with the real technological production requirements and can be used for theoretical and engineering analysis. The mathematical model of the technological line processing organic raw materials is based on the theory of artificial neural networks. The model can be further improved to be used in the system for automatizing technological operations and monitoring the quality indicators of modular equipment in the processing of organic raw materials. This will provide a new level of synthesizing complex technical systems, which will be beneficial for agricultural production.

Conventional methods of seed pelleting involve using pelletizers with a drum-type working unit. In these devices, pelleting is carried out in a cyclic mode, which makes operational restrictions and complicates the use of pelletizers in the technological line of complex pre-sowing seed treatment. The authors evaluate the effectiveness of belt-type pelleting machines ensuring the continuity of pelleting and significantly increasing the performance. The paper provides some basic requirements to continuous seed pelletizing. The conditions are determined to describe the pellets rolling down the inclined surface of the moving conveyor belt. Consequently, the analytical relationship is established between the inclination angle of the pelletizer belt and the friction coefficient, the pellet diameter and speed of their forward movement along the conveyor belt. The main operating parameters of the belt pelletizer are determined - length, speed, and the inclination angle of the conveyor belt. The obtained mathematical expressions are universal, since they allow analyzing the working parameters of the pelletizers when processing crop seeds with different initial size, weight, and tribotechnical properties. When studying the movement of the coated seeds along the moving belt of the inclined conveyor, the friction force acting on them, the reaction force of the support, the authors took into account the rolling force and the gravity force. Based on the analogy of the translational movement of seeds along an inclined plane to their movement along the inner surface of the drum of an infinitely large radius, the authors established the numerical values of the parameters of continuous pelleting. The paper finishes with a conclusion about possible reducing the dimensions of the belt-type pelletizer. The estimated length of the working area of the conveyor belt is suggested to be the sum of the lengths of several belts inclined to the ground in different planes.

At present, shallow tillage plays a leading role in the technological process of cultivating agricultural crops, as it is one of the key operations in soil preparing for sowing. To establish the optimal parameters of the working tool for shallow tillage, the authors designed the tool capable of using various main operating elements (a flat hoe and a post lining). The main criterion for optimizing the parameters of the working tool was the traction resistance. Experimental studies were carried out in the field conditions. The optimal operating parameters of the working tools for shallow tillage were determined against the stubble background of winter wheat after its disc plowing in one track. The experimental research methodology included planning a multi-factorial experiment. The main changing factors included: the share opening angle of the flat hoe of the working tool; the sharpening angle of the working tool post and the soil cultivation depth by the working tool. Based on data processing and analysis, the authors obtained a regression equation, which helps calculate the traction resistance depending on the specified parameters of the working tool and the soil cultivation depth. As a result of experimental studies, the optimal parameters of the working tool were determined: the share opening angle of the flat hoe g = 104°, as well as the sharpening angle of the working tool post f = 50°. At a tillage speed of 8.20 km/h, the minimum traction forces generated by a single working tool with an operating width of 0.5 m at the depth of 8 cm is 1.902 kN, at 12 cm - 2.482 kN and at 16 cm - 4.758 kN. The data obtained can be used in the design of working tools and agricultural machines for shallow soil cultivation.

A significant part of the losses during harvesting by modern combines is caused by the imperfect systems for copying the field terrain. After analyzing and reviewing patents of the mechanisms for copying the field topography by harvester headers, identifying the main advantages and disadvantages of these devices, the author proposes a variant of retrofitting the most common lever-spring copying system that provides automatic adjustment of the cutting height when it goes beyond the copying limits provided by the manufacturer. The device consists of two main parts, one of which is attached to the body of the feeder house, and the second -to the upper bearing bar of the header. The device has two magnetic contact sensors connected to the electric control system of the header position. When the header is operating within the prescribed range of copying, the lever-spring system operates in the normal mode, allowing the header to go around field irregularities and maintain the specified pressure of the support shoes on the ground. When the header moves to the limit of the copy range, the corresponding hydraulic system control sensor is closed and the feeder house height is automatically changed, which prevents the header from galloping or digging the support shoes into the soil. The proposed version of the upgraded terrain copying mechanism does not require significant costs, reduces the complexity of the combine control, improves its average shift productivity and reduces crop losses due to the operator's belated reactions to changes in terrain.

The problem of air pollution in agricultural premises leads to a decrease in the weight gain of animals and poultry, an increase in morbidity, as well as a deterioration in the sanitary working conditions. The air in poultry houses contains dust particles of various origins and sizes, as well as pathogens and harmful gases. Therefore, air purification in poultry premises must be approached comprehensively. An analysis of the air purification installations used in agricultural premises showed that these installations do not have a high efficiency of dedusting and disinfection at the same time. To solve this problem, the authors propose to use a combined electrical installation for air purification, which uses two electrotechnological methods of air purification – electrofiltration and ultraviolet radiation. Tests were carried out on two groups of 35 quail chicks in each group. The chicks were kept in a box according to the cage housing method. Concentration of dust particles in the air of the poultry house was determined with PC-GTA 0.3-002, air parameters and chemical composition – with Meteoscope-M, Testo 440 and H-320 gas analyser. Measurements were taken after 3 hours of operation in the center of the room at a height of 1 m above the floor. The reliability of the results was confirmed by multiple repetitions of studies and reproducibility of the obtained data, the use of conventional methods, devices and mathematical processing of the results. The relationships between the concentration of dust particles, quantity of gas components, and the operating time of the combined electric air-cleaning unit were studied, the effect of air sanitation on the living weight of poultry was determined. It was experimentally established that the use of the hybrid electrical installation in a box with quail chicks led to a decrease in the bactericidal contamination of the room by 59%, the concentration of carbon dioxide by almost 4% and ammonia by 45% as compared with the control box. The use of the proposed installation increased the gain in the live weight of chicken by 20.3% on day 28.

The most important part that limits the engine life is the cylinder liner. Before fault finding in the cylinder liners, it is necessary to carry out the micrometry of their surface to identify the areas of greatest and least wear. For carrying out the micrometry and testing it on new and worn cylinder liners, 40 cylinder liners of YaMZ engines were used. The working surface of the cylinder liners was controlled by the inner diameter, which was measured in eight sections and two planes. The micrometry was carried out with an indicating hole gauge with a digital head of increased accuracy with a sensitivity of 0.001 mm; ten new cylinder liners met the technical requirements. The micrometry of thirty cylinder liners showed that the greatest wear was 253 μm in the connecting rod oscillation plane and 189 μm in the perpendicular plane. It was found that liner micrometry should be particularly thoroughly carried out at the top of the cylinder liners. The greatest wear occurs at the top piston ring stop at the start of the expansion stroke, with more intensive wear in the connecting rod oscillation plane due to the normal force. The uppermost part of the cylinder liners is the wear-free liner flange, the diameter of which indicates the original dimensions of the liner bore. However, it must also be measured due to the effects of high temperatures, changes in the crystal pattern of the material, oxidation and the presence of combustion products in the form of carbon deposits. The lower part of the cylinder liner is subject to wear due to the friction of the piston skirt against its surface. However, due to the lower temperature, the better lubrication, the much larger contact surface and the correspondingly lower pressure, increased wear here can only occur if there are misalignments in the crank mechanism: the misaligned crankshaft axle or the bent connecting rod.

The static theory of honing has not been sufficiently developed, since the process of mass cutting with abrasive grains is random by its nature. This fact complicates the mathematical description of this phenomenon. The research aim was to develop a technique for modeling honing to calculate the process parameters, taking into account the elastic deformations of the abrasive tool. To solve the problems of statistical theory (analyzing the microgeometry of a machine part, metal removal and cutting forces), the studies involved probabilistic analysis and Monte Carlo simulation. Based on the distribution probability of abrasive grains over the cutting layer of the tool and the process kinematics, the law of distribution of the heights of part microroughnesses was determined. Using the distribution law, the authors found the parameters of the surface roughness of the part and the cutting process characteristics: the area of cuts, the number of contact grains, etc. A mathematical relationship has been established between the distribution of abrasive grains along the height and the distribution of the depth of scratches left by the tool on a polished sample. The geometric parameters of the cutting surface of diamond bars were determined taking into account their discrete model. Comparison of the calculated and experimental values of the bar parameters proved the correctness of the proposed methodology. Analytical dependences were obtained in general form for determining the parameters of the surface roughness of the machine part, the metal removal rate, cutting forces, cut areas, the number of contact grains, etc. The developed honing modeling technique helps determine the process parameters taking into account elastic deformations of the abrasive tool. Taking into account the characteristics of the bars, the average profile of the grains and the density of their distribution along the height, we can determine all the parameters of the machine part microgeometry. The results of the conducted probabilistic research are also applicable to other types of abrasive processing.

Modern industry places a number of stringent requirements to the performance properties of fasteners. All fastening elements made of metal are subject to corrosion-mechanical wear. Their disassembling is a time-consuming process which is often accompanied by destruction of the part. Damage to threaded connections can be prevented by applying a special thread lubricant to the part. Based on theoretical and experimental research, the authors have developed a formulation of high-temperature thread compound "Udar", which contains the following components: molybdenum disulphide (70 wt.%), titanium dioxide (3 wt.%), colloidal graphite compound (70 wt.%), aluminium (powder) (5 wt.%), OMIK "TELAZ" (10 wt.%), thickener (petrolatum), and industrial oil I-40A. The lubricant efficiency in protecting fasteners against atmospheric corrosion and corrosion setting was tested on six specimens representing a pair of "bolt-nut". The results of comparative laboratory tests of the developed composition with foreign-made greases have shown that the developed thread lubricant is able to protect threaded joints from thermal-oxidative setting occurring at up to 900⁰C. Application of this composition will considerably reduce the equipment disassembling time due to reduction of the absolute value of torque when disassembling fasteners, and prevent thermochemical and corrosion "seizure" of threaded joints

At present, it is necessary to improve not only repair technologies, but also consider the possibility of using various modified materials to increase the post-repair reliability of agricultural machinery. One of the ways to improve the rubber seals of bearing assemblies is to modify them by adding organofluorine compounds to the rubber composition, which have a complex effect on rubber, improve its physical, mechanical, and tribological properties. To determine the modification effect of seals on friction and wear, the author tested joints consisting of a steel bushing with a diameter of 45 mm with a surface hardness of at least HRC32 and collars of three types: serial (GOST 8752-79); modified with alcohol-telomer (FS-1) and fluoroparaffin (FS-2) in the amount of one mass part of PS per 100 mass parts of rubber. The collar wear was determined by changing the width of the working edge, measured by DIP-6 with the optoelectronic measuring system NILK-890. Bench tests showed that volumetric modification with organofluorine compounds improved the properties of rubber: the wear of modified seals decreased in 1.83...1.94 times compared to serial ones, friction coefficient decreased in 1.32...1.37 times.

Ground faults in networks with an isolated neutral are not switched off by relay line protections due to low capacitive currents. It is recommended to disconnect the line with a earth fault as quickly as possible, but sometimes it is difficult to find and localize the damage. To analyze the emergency mode of single-phase ground fault in networks with an isolated neutral, the phase coordinate method for calculating phase voltages is used. At the point of damage, the values of the phase-to-phase voltages remain unchanged, and the phase voltages change. Real research and analysis of electrical network modes of 6-35 kV with an isolated neutral is rather time-consuming task. Therefore, the calculation of phase voltages at the substation during an earth fault is carried out through the transition resistance on the line based on the phase coordinate method. The authors developed a virtual model of studied power transmission line for analyzing asymmetric modes of three-phase networks and checking the operability of the method in the MATLAB Simulink simulation package. The simulation results showed that there was no discrepancy between the voltage and current values of the original model in phase coordinates and the Simulink model. As a result of the research, the authors have found that the phase coordinate method helps calculate emergency modes with the overlay of several component accidents taking into account load currents. The model in phase coordinates will allow analyzing relay protection operation at high speed under different operating modes of the electric power system.

The high productivity of farm animals requires that the feeding ration should contain all the necessary nutrients to meet their needs. Before offering to animals, feeds are subjected to additional processing to increase their nutritional value and palatability. A promising method is the treatment of roughage with activated media. The authors designed and described the operating principle of a single-phase flow-type electric activator with a belting-type diaphragm. It has optimal parameters to prepare the required amount of activated water (catholyte) for processing roughages in the amount of five tons per season. To justify the operating modes of the electric activator, a matrix of active planning of a three-factor experiment was used. When choosing the intervals for changing factors (the electric activator power, performance, and cycle), the authors were guided by the technological conditions of electrochemical activation of the liquid and the activator design features. The efficiency of the liquid activation process was determined by the value of change in the hydrogen index of the activated solution, the voltage loss on the electric activator, and the current density. Regression models were obtained to optimize the operating modes of the activator. Based on the equations obtained, it is possible to change the variable parameters to obtain the desired proportions of the input and output parameters of the installation.