When applying livestock wastewater to agricultural fields, it is necessary to reduce its ammonium content. In order to develop more effective methods of wastewater treatment, the authors studied the effect of electric field on the change in the concentration of ammonium nitrogen compounds in aqueous solutions (the electrolyte). Experimental studies were carried out on the developed installation using the principle of electrolysis. Distilled water with added ammonium nitrate was used to simulate the ammonium content in the electrolyte. The 500 ml electrolyte was placed between the electrodes and treated with direct current for 1, 3, 4, and 9 min. The studies were carried out at the NH4⁺ concentration in the electrolyte of 60, 90 and 300 mg/liter. When the experiment was completed, the authors determined the concentration of nitrogen compounds and the hydrogen pH of the electrolyte. It was found that the exposure of NH₄⁺ aqueous solution to the electric field leads to a decrease in the concentration of ammonium nitrogen compounds and a change in the pH of the electrolyte from the acidic to alkaline reaction. No ammonium compounds were detected in the solution after a 9-minute treatment of the electrolyte with the NH₄⁺ concentration of 60 and 90 mg/liter. Treatment of the solution with the NH₄⁺ concentration of 300 mg/l for 1 min led to a decrease in the ammonium concentration to 75 mg/l. This fact indicates the viability of this method of treatment and the development of an industrial sample of technical means to treat livestock wastewater. Reducing the ammonium nitrogen concentration will decrease the ecological load on soil, ground and surface waters, and improve the quality of crops grown on the farmland, supplied with wastewater from livestock facilities. Changing the pH of electrolyte from the acid to alkaline reaction will have a positive effect on the acidic soils of the Central Non-Chernozem (Black Soil) Zone of the Russian Federation.

The use of anticorrosive agents increases the service life, reliability and safety of agricultural machinery.

The shortage of domestic inhibitors is caused by the lack of a scientifically sound concept for their production, as well as a lack of raw materials. The authors have developed a technology for the production of fatty acid amides (FAA) from triglycerides of vegetable, animal origin or fat-containing waste. The purpose of this study was to evaluate the effectiveness of fatty acid amide used as an inhibitor of atmospheric corrosion. A comparative assessment of the protective effectiveness of FAA was determined in accordance with GOST 9.054-75 at elevated values of relative humidity and air temperature, exposure to salt mist, with constant immersion in an electrolyte and exposure to the hydrobromic acid. The authors compared preservation compositions based on FAA 16%, Avtokon LS, Kormin 50%, Rosoil 700, Kormin 30%. The protective properties of the products were studied on samples with dimensions of 50 × 50 mm made of steel grade St3. After the tests, the appearance of the samples was evaluated before and after removing the lubricant. According to the results of each experiment, the protective properties of the preservation compounds were arranged in the decreasing order. According to the results of four experiments, each composition was assigned a score characterizing the total assessment of the protective ability of the compositions according to GOST 9.407-2015. As a result of the study, the relationship between the effectiveness of preservative oils and the composition and amount of the inhibitor has been established. The effectiveness of fatty acid amides used as an inhibitor of atmospheric corrosion has been proven. Preservation oil made using 16% FAA exceeds the protective effect of analogue products in 1.1 to 2.0 times.

Segment-finger mowers are used mainly in forage harvesting. To improve their qualitative and operational indicators it is necessary to study the trajectory of movement, speed and acceleration of the mower knife under variable terrain conditions. For this purpose, the authors studied the influence of change of the non-axial value on qualitative and energy indicators of the mower’s cutter bar. They also determined parameters and operating modes of the mower knife with the axial knife drive mechanism. According to the results of experimental studies, it was established that while copying the field relief, the cutter bar changes the angle of inclination relative to the horizon within the limits of ±15 degrees. In this case, the non-axial value varies between 0.281 and 0.492 m with a step of one degree. The change of the non-axial value entails the change of the stroke, speed, and acceleration of the knife. Using the analytical method of kinematic study of crank mechanisms according to Artobolevsky’s procedure and performing calculations in the Excel software kit, the authors have obtained graphical relationships between the knife stroke and speed depending on the angular position of the cutter bar with the interval of 0, 5, 10, and 15. A change in the location of the cutter bar up to 15 degrees causes unequal speeds of the forward and reverse knife strokes, increasing it from 76.2 to 89 mm, which increases the energy consumption for the knife drive up to 17%. Another disadvantage of the non-axial crank mechanism of the knife drive is its dynamic unbalance, which is only partially smoothed with a counterweight. To eliminate the drawbacks, the authors have developed an experimental mower with axial arrangement of the crank mechanism on the finger bar of the cutter bar. The new design makes it possible to activate the transport position of the finger bar in the working mode of the cutter bar when bypassing such obstacles as bushes, trees, or rough bumps.

The long service life of a farm sprayer depends on the material, the nozzles are made of. To increase the wear resistance of polymer nozzles, dispersed fillers are incorporated into the composite. Composites for agricultural sprayer atomizers should have high chemical resistance to agrochemicals and mechanical strength, as well as low hydro-abrasive wear. In order to select the optimal polymer composite for farm sprayer atomizers, three composites based on polyoxymethylene of MASCON POM 27 brand were produced, in which glass fiber, graphite and silicon carbide with the degree of volume filling 10, 15 and 20% were used as disperse fillers. The polymer composites were tested for 14 weeks for chemical resistance to agrochemicals (herbicide “Lazurit”, fungicide “Rakurs”, insecticide “Borei-Neo”), mechanical strength and hydro-abrasive wear. MASCON POM 27 polyoxymethylene samples served as a reference. The results of mechanical tensile strength tests showed the greatest increase in the strength index at 15% filler content regardless of its type. The strength of the composite with silicon carbide increased by 30.2%, with glass fiber – by 26.8%, with graphite – by 27.4%. It was found that the chemical resistance of composites does not depend on the concentration of agrochemical solution. The experiments on hydro-abrasive wear revealed that graphite and silicon carbide are effective as fillers and can reduce wear up to 7.5 times. It is recommended to use polyoxymethylene with 15% content of silicon carbide for manufacturing farm sprayer atomizers.

Characteristic defects of internal combustion engine crankshafts of automotive vehicles include wear of friction surfaces – journals, faces, grooves and threads, – as well as residual deformations and fatigue cracks. To eliminate defects, crankshafts are repaired using technological operations to restore the shape and location, linear and angular dimensions, as well as roughness, wear resistance and fatigue resistance of elements and surfaces. To analyze the restoration techniques of crankshafts of automotive vehicles the operating conditions, the authors considered the main defects and types of surfacing and spraying applied by means of electric arc, gas-flame, detonation, and plasma (induction and plasma-arc) methods. The authors note that to meet reliability requirements, the restored parts should have a ratio of hardness (НRС_в/НRС_н) and fatigue strength (G_-1B/G_-1H) higher than one as compared to new parts. However, no crankshaft restoration technique fully meets this requirement, because the wear resistance of new crankshafts in most cases is higher than that of restored parts. Based on the analysis of crankshaft restoration techniques, the authors determined the following effective ones: the finishing antifriction non-abrasive treatment (FANT) with the use of antifriction, wear-resistant and solid lubricant coatings applied to the parts using various methods. This technique increases wear and corrosion resistance, resistance to fatigue wear, and improves the running-in of the rubbing machine parts.

Mechanical processing of critical parts affects the quality of engine repair. The authors carried out research to assess the quality of setting for machining the crankshaft main journals of the ZMZ engine for the repair size. They studied the diameters of 20 crankshaft main journals of the ZMZ engine after machining for the repair size. The diameters were controlled by a lever clamp SR-75. The following tools were sequentially used to evaluate the quality of machining main bearing journals: a “box-and-whisker” diagram, Shewhart control charts, and a histogram. According to the “Box and Whiskers” diagram it was found that after machining for the repair size all the journals have a diameter within the machining tolerance field, but at the same time there is a scatter between the diameters of the journals of the same crankshaft. After analyzing the Shewhart control charts, it was found that the scatter values within one subgroup (crankshaft) and between the subgroups were caused by the usual reasons, and this scatter pattern can be considered random. Consequently, the technological process can be considered stable and controllable. The histogram helped to determine the probability of correctable rejects after machining of the engine journal for the repair size, equal to 1.95%, and the probability of irreparable rejects, equal to 0. The calculated reproducibility index of 0.93 indicates a significant wear of the equipment. Over time, the index will decrease and the risks of rejects will increase. The authors conclude that the quality of setting for machining crankshaft main bearing journals for the repair size is acceptable. It is desirable to regularly check the quality of machining crankshaft main journals for the repair size, consistently applying all the three tools to identify the size variation and inconsistencies, which is especially relevant for worn equipment.

The quality of cleaning metal parts from contaminants depends on the physical and chemical properties of the washing medium and the intensity of the mechanical impact of the liquid on the surfaces subject to cleaning. Intensified cleaning of the parts is possible when there is an unsteady mode of a washing liquid flow, characterized by change of pressure and speed of a liquid in time and in each considered point of a surface subject to cleaning. In order to confirm the theoretical statement about the dependence of cleaning efficiency on the speed of the washing liquid flow, the authors made an experiment. They took a combined submerged washing machine using a combination of two hydromechanical methods of cleaning intensification. The parts subject to cleaning moved in the bath by means of the platform vibration. A helical blower provided the turbulent flow of the washing liquid relative to the object subject to cleaning. The authors used connecting rods of internal combustion engines as the objects to be cleaned. Their surfaces contained asphalt-resin contaminants, which were hard to remove. The cleaning process was studied in the aqueous solution of detergent Temp-100D with a concentration of 20 g/l at a temperature of 65 to 70°C. The cleaning lasted for 15 min. The quality of cleaning from contaminants was controlled by wettability of the cleaned surface with water. It was found that the intensity of cleaning, characterized by the liquid flow rate necessary for the detachment of dirt particles, depends on the vibration frequency of the platform holding the cleaned parts. Increasing the vibration frequency from 0.25 to 1.0 Hz leads to a three-fold increase in the flow rate of the cleaning solution, which provides an intensive removal of contaminants while increasing the quality of cleaning. When increasing the vibration frequency from 0 to 1.0 Hz, the cleaning efficiency increases in 2.5 times. The study results confirmed the theoretical supposition of the relationship between the cleaning efficiency and the washing liquid flow rate.

The main characteristic of the performance of submersible electric motors after overhauls is their reliability. To assess the compliance of reliability indicators of restored submersible electric motors with technical requirements for overhauls, various types of tests are used. The most acceptable of them is the bench test method based on a sequential failure analysis of the studied electric motors. To implement it, the specified parameters should be set. In this study, based on the use of technical requirements for the manufacture and repair of submersible electric motors, the authors determined the specified average operating times for failure of new electric motors (before the first overhaul) and after it. Bench tests were carried out for two batches of submersible electric motors: overhauled and non-overhauled. In each batch, 20 electric motors were studied. The experiment determined the standard deviation of the mean time between failures (MTBF) of new electric motors, which amounted to 3.54 thousand hours, after the overhaul – 2.37 thousand hours. The coefficients of variation were 0.3 and 0.34, respectively. The study results determined the values of the set parameters of the mathematical model, enabling the use of the method of successive failure analysis. The values included the set average MTBF before the first overhaul – 16 thousand hours; the set average MTBF after the overhaul – 12.8 thousand hours; the risks of the repair provider and the customer – 0.05; the set mean square deviation of the MTBF of electric motors before the first overhaul – 4.8 thousand hours; the set mean square deviation of the MTBF after the first overhaul – 4.8 thousand hours; the set mean square deviation of the MTBF after the overhaul – 2.37 thousand hours.

Modern methods of pre-sowing seed treatment disinfect seeds, increase yield and plant resistance to adverse environmental factors, and stimulate plant immunity. Among the methods of electromagnetic impact on bioobjects, irradiation of seeds with ultraviolet light is simple, energy-efficient, economically beneficial and environmentally safe. The research aimed to study the effect of UV irradiation for pre-sowing treatment of thuja seeds and empirically determine the effective dose of UV irradiation. To maintain the required UV irradiation dose, the authors developed a digital control system on ATMEGA128A microcontroller (ATMEL). The working area of a 12 × 12 UV matrix consisting of 200 UV LEDs was 144 cm². The distance from the UV LEDs to the irradiated seeds was about 2 cm. The UV dose of the matrix was controlled by monitoring the voltage drop on the NSL-19M51 photoresistors. The irradiance of the LEDs in the UV-A (UV-A) zone corresponded to 98%. In each series, 100 seeds of thuja occidentalis were irradiated; the experiments were repeated four times. The authors studied UV irradiation doses of 2 kJ/m², 3 kJ/m², and 4 kJ/m². Seeds of thuja occidentalis without UV irradiation treatment were used as a control. The effective dose of UV-irradiation of seeds was determined empirically. The determined UV irradiation dose of 2 kJ/m² is able to increase seed germination energy by 12.8% as compared to the control. Statistical processing of empirical data showed satisfactory accuracy of the conducted experiments. The accuracy index of the experiment amounted to P=1.76%±0.65%, for the control (without UV irradiation) – P=1.33±0.47%.

The air environment of livestock buildings requires disinfection and improvement of the gas composition. The most effective method is ozonation. In order to improve the air inside livestock buildings, the authors have developed an electric ozonizer-emitter. Its emitter module consists of two ceramic bases with different-potential tungsten electrodes, one base having an electrode in the form of a honeycomb cell, and the other – in the form of a rod. The ozone productivity is regulated by changing the discharge gap between the emitter electrodes and the conducting plane. It has been theoretically established that ozone formation in a corona discharge depends on the electric field strength between the different-potential electrodes and their heating temperature. In this case, the maximum strength is achieved with a discharge gap from 25 to 35 mm and electrodes with a radius of no more than 2 mm. The effect of electrode heating temperature on ozone formation was studied on the developed design of the ozonizer-emitter in a laboratory of 180 m³ at an air temperature of 25°C above zero. The air gap between the electrodes was 30 mm, the voltage on the emitter varied from 10 to 30 kV, the duration of the ozonizer-emitter operation ranged between 0 and 80 min, the airflow rate induced by the electric fan was 0.3 m/s. It was experimentally established that stable operation of the ozonizer-emitter is observed when the electrode temperature does not exceed 30°C. In the future, the authors plan to introduce the ozonizer-air emitter into the ventilation and air conditioning system of agricultural buildings.

The disposal of animal waste products is especially urgent at large livestock facilities. In order to develop an effective technology of processing animal manure effluents, the authors have developed an effective method of their treatment and designed an experimental installation – a manure effluent treatment station including an electro-ozonizer. Cleaning is carried out in two stages: at the first stage, manure effluent is subjected to separation and flotation to remove large dispersed impurities, at the second stage, liquid fraction is treated with ozone. The technical result is achieved by fine atomization of manure effluents with a droplet diameter from 1.0 to 10.0 microns in the ozone-air mixture at an ozone concentration of 450 to 500 mg/m³. Calculations based on the developed mathematical model have shown that fine atomization of manure effluents in a chamber with the ozone-air mixture increases the ozone concentration gradient and ozone mass transfer through the interface in 360 times as compared with barbotization of ozone into liquid. This makes it possible to increase significantly the rate of ozone consumption in chemical reactions, increase the efficiency factor, and reduce energy consumption for manure effluent treatment. The experiment was conducted at the pig-breeding farm of LLC “Novye Agrarnye Tekhnologii”, Beysuzhek Vtoroy, the Vyselki district, the Krasnodar region. The results of chemical, organoleptic and microbiological analyses confirm the high efficiency of the developed method and equipment for wastewater treatment of pig farms. The developed electro-ozonization technology and equipment improve the ecological situation on livestock farms by preventing the discharge of harmful emissions of ecologically toxic volatile compounds into the atmosphere.

In higher education, blended learning technology combining e-learning and classroom activities has become widespread. Blended learning contributes to the introduction of variable forms and ways of interaction between students and teachers, interaction of study process participants with content, and the expansion of the teacher’s toolkit when working with students. In order to identify and justify the pedagogical conditions of effective organization of blended learning in universities, the authors have described the essence and main components of blended learning technology, and the options of its implementation using learning management systems (LMS). LMS can be classified as to types of licensing, a set of functionality, the module-based criterion, the “customer requirement” criterion, and physical location. The articled presents and identifies features and capabilities of one of the most common learning management systems – LMS MOODLE. The authors reveal pedagogical conditions for the successful implementation of blended learning technology at a university: development of a syllabus and training curricula, correlation of the possibilities of their implementation with the use of blended learning technology; competent course design and implementation, as well as active updating of the content of LMS courses to ensure their quality and relevance; providing timely teacher support for communication and feedback with students; development and application of special methods for monitoring and assessing educational results to carry out reliable and valid diagnostics of learning outcomes and provide prompt feedback; development of high-quality methodological support for teachers on the organization and implementation of the educational process in new conditions and produce methodological materials for students; ensuring a high degree of readiness of students and teachers to implement training in a new format, organize their training and support end contribute to the development of digital competences.