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Choosing rational design parameters of the coupling device for multi-section aggregation of seeders, it is possible to ensure full loading of the power unit while maintaining quality indicators of the technological process at a sufficiently high level. Foreign aggregates are not suitable for use in the Russian Federation due to the different soil and climatic conditions. Purpose of the study: to develop an effective device for multi-section aggregation suitable for domestic modern seeding machines. Subject of the research: the relationship of design parameters and modes of operation of the device for multi-section aggregation of seeders with indicators of the technological process of sowing. A monographic survey of known structures has been carried out, a device for multi-section aggregation of seeding machines has been substantiated by the design and construction method, indicators of the technological process of sowing have been experimentally obtained. The developed coupling device for multi-section aggregation consists of a central frame resting on the wheels and articulated side sections: left and right, which fold when transporting the seeding unit. The total working width of the seeding unit is up to 12.5 meters. According to the research results, the quality of the technological process by the seeding devices meets the regulatory requirements. The instability of the total seeding (0.6–1.1 % for barley and 0.4–0.7 % for wheat) is within the tolerance (up to 3 percent); uneven seeding between devices 3.9–4.2 percent (barley) and 2.6–4.2 percent (wheat) corresponds to the norm (up to 5 percent). The number of seeds embedded at a predetermined depth of the soil corresponds to the required (not less than 80 percent) and was 81.8–83.9 percent for barley and 80.1–83.3 percent for wheat. Not embedded seeds were found in the soil.

The article discusses the options of working bodies for tillage of steam fields in the summer. These studies are aimed at obtaining agrotechnical indicators of the technological process of tillage of steam fields. In particular, the design of the working body in the form of a flat one-sided paw is proposed. Laboratory and field studies were carried out to determine the qualitative indicators of the technological process of fine tillage, with all variants of working bodies. During the research, such indicators were established as: the optimal (recommended) speed of the unit, the depth of tillage by working bodies, the width of the unit (working), the average square deviation in the depth of processing and the width of the grip. The aggregate composition of the soil was assessed by fractions, the content of erosive-hazardous particles before and after the passage of the unit, pruning or destruction of weeds and the ridge of the field surface after the passage of the unit. Data on the dynamics of soil moisture after several treatments of steam fields with various variants of working bodies were obtained. As a result of the research, it was found that the working body in the form of a flat one-sided paw, in comparison with the working body of a serial steam cultivator, allows to reduce the depth of processing by 1.6 cm (up to 5.2 cm), to reduce the value of the combiness of the treated surface by 2.4-3.4 cm, while ensuring complete pruning of weeds both annual and perennial. The variants of working bodies considered in the article for processing steam fields in the summer and the studies carried out to determine their quality indicators will allow creating machine-technological units for promising mechanized technologies of tillage in arid agriculture.

As known, seed drills are the most complex agricultural machines in terms of the performed technological process since they include a number of sequentially or concurrent operations. The modern crop farming technologies shall include practices that improve soil fertility through the application of organic and mineral fertilizers. Sustainable crop production is carried out with environmentally friendly and economically competitive farming methods. The object of this paper is to determine the main agrotechnical parameters of universal seed-fertilizer stubble drill SZS-4U. The research methodology has involved determination of the main agrotechnical parameters of the seeder. Based on the research results it was found that the uneven seeding of winter and spring wheat at two speed modes was 2,98% and 3,04%, for spring barley is was 2,70% and 3,00%, mineral fertilizers – 7,57% and 7,69%. With the optimum depth of the openers, the actual depth of seeds placement of spring wheat was 56,5 and 48,9 mm, winter wheat – 44,5 and 43,9 mm, spring barley – 48,0 and 44,3 mm, these data meets a given depth of seeding. After SZS-4U has passed there’s been retained 68,12 – 72,38 percent (%) of stubble on unprepared or minimally prepared grounds, and these values meet agrotechnical requirements which stipulate at least 65 ± 10%. Thus, we can conclude that the universal seed-fertilizer stubble drill SZS-4U meets all agrotechnical requirements and stipulated indicators in terms of sowing winter wheat, spring barley, and spring wheat with simultaneous fertilization.

Purpose: to study the technological process of loosening the soil with a flat-cutting blade and a tine. Materials and methods: the methods of analyzing the power impact on the tine, as well as the theoretical provisions of failure hypotheses are used. As an object of research, the working bodies of tools with a horizontal cutting edge were considered, namely, flat-cutting blades which are used for overall tillage. Results: as a result of studies it was found that the main parameters of flat-cutting blades include: operating width Bi, opening angle 2γ, crumbling angle β0, edge angle i0, band width b, which determine the blades shape and the nature of the impact on the soil. When considering the layout of the soil deformation zones, i. e., the simultaneous combined effect of the tine and plowshares of the horizontal blade, it was found that the zones for obtaining fine soil fractions increase, and a decrease in the thickness t of tine and the operating width of the share B affects the crumbling value. This, in turn, allows regulating the zones for obtaining fine soil fractions and determining the optimal composition of blade width and tine thickness for better crumbling. Conclusions: according to the research results, it was found that the generalized estimated indicator (W) of options for deep tillage ranges from 0.82 to 0.84, for shallow loosening from 0.84 to 0.87, and for surface shallow tillage from 0.845 to 0.870. For loosening soil with mixing crop residues with soil particles, the option W = 0.84 with a vertical tine t = 2.0 cm and a blade operating width of 42.0 cm is acceptable. For surface and presowing tillage, the most suitable options are WX = 0.87 and WXI = 0.85, allowing carrying tillage to a depth of 6–10 cm.

Tillage is considered to be the methods of mechanical impact on the soil, contributing to the improvement of its fertility and the creation of better conditions for the growth and development of plants. Layerless processing without cover takes one of the most significant operations carried out during the preparation of the soil. This is confirmed by the fact that layer-by-layer processing promotes the accumulation of moisture inside the soil layer, the separation of the seam into layers, and the reduction of soil erosion. The aim of the research is to improve the design features of the main elements of the working body for layer-by-layer soilless tillage. Based on the methods of analysis and synthesis of research, as well as modeling, an improved design of the working body was proposed. It provides for the possibility of replacing almost all the main elements as they wear out, which in turn indicates a high level of wear resistance of the developed structure and a significant reduction in labor costs during its maintenance. In addition to the use of metal basic elements of various shapes (flat-cutter, curvilinear ripper) in the design of the working body, the use of ultra-high-molecular polyethylene inserts partially or completely replacing the main structural elements of the working body is also provided. Experimental studies have found that the traction resistance of the working body using a flat-ripper in the construction is 9,30 kN, with a curvilinear ripper 8,04 kN, which is 13,56 % lower than the flat-cutter. With the use of ultra-high molecular polyethylene inserts, a decrease in traction resistance of up to 7,6 kN was observed, which is 18,28 % lower compared to a flat-ripper. The proposed design allows layer-by-layer soilless tillage, carrying out at the same time a deep 25-35 cm and shallow 12-16 cm tillage, and also allows to obtain an aligned field background after the passage of the unit.

The working bodies of tillers perform the most important role from the point of view of the technological process of tillage, as they provide all the parameters of its application. The purpose of the study is the justification of the parameters of the column of the working body of the tiller machine. The traction resistance as the main parameter of the working element is affected by the shape of lateral profile and cross-section of the column. In general, in the cross section, the columns of the working bodies can have: a plane with rectilinear boundaries, a plane with curvilinear convex boundaries, or a plane with curvilinear concave boundaries. The compacted core of the soil in front of the stand is not formed when the grinding angle is not more than 50°. In all other cases, such a nucleus is formed even at asymmetric sharpening angles. Consequently, the necessary condition for the shape of the cross section of the column should be the observance of the value of mentioned angle. The cross-section of the column (Folium of Descartes) meets the requirements imposed on it, as the sharpening angle does not exceed 50°, which does not contribute to the formation of the compaction core, and the boundary has the shape of a convex line, which ensures a minimum absolute speed, on soil movement. The column of the working body of the tiller machine should have the shape of a lateral profile close to the logarithmic curve, which reduces the energy intensity of the process by 20 ... 45 %, and in the cross section of the column there must be a plane bounded by arcs of the ellipse and tangent to these arcs drawn so that the angle at the top of the ellipse did not exceed 50°. This reduces the traction resistance of the column by 40 ... 52 %.

The machine-tractor unit is a key element in an implementation of technological operations in the cropping. Running gears with wheeled and caterpillar propulsion device are used in the modern tractors. During an interaction of the ground with tractor propulsion devices, the ground is pulverized on one side and it is compacted on the other side during the slipping. Besides, the wheeled movers have the slipping several times higher than caterpillar movers. The aim of the research is an analysis of running gears of machine-tractor units and their influence on the quality of performed technological operations. The paper discusses an analysis of parameters of wheeled and replaceable caterpillar movers to the tractor K-701, which have the same dimensions. One of the main external influences on the unit is the surface profile of the field. The main source of tractor oscillations are the unevennesses of the way. At the same time, characteristic areas for the operation of machine-tractor units are very various, the most characteristic of them are a stubble field, a plowed field, a prepared field, a field road and others. The analysis of spectral densities of the surface profile of the field on which the tractor operates shows that with increasing speed, the spectral density decreases rapidly, and the maximum of the spectral density shifts toward higher values of the frequencies. It has been established that the frequency range, which has the greatest effect on the machine-tractor unit on the basis of the tractor K-701 on the replacement caterpillar mover 1...4 sec-1, on the wheel mover - 1...7 sec-1. The replaceable caterpillar mover for a 5 сlass tractor has significant advantages over a wheeled mover, since it filters (smoothes) 2,1...2,8 times more irregularities, which improves working conditions, smooth of running and other indicators of the machine-tractor unit.

The most significant feature of the operation of agricultural machine-tractor aggregates is the random nature of external influences, which determines its output indices. The main task of the theory of complex systems should be considered the development of methods that allow on the basis of their functioning to obtain the characteristics of individual elements and analyze the interaction between these elements and the external environment, to determine the characteristics of the system as a whole. The purpose of the study is to analyze the characteristics of external influences as a reaction to the operation of machine-tractor units. When solving many problems of agricultural mechanics (researching technological and production processes, building models and synthesizing the parameters of working organs and aggregates), it is necessary to take into account the external factors that determine the main regularities of various processes. The process of operation of the unit can be represented in the form of a set of states - vectors of output quantities: agrotechnical, technological, kinematic, energy-power and so on. The role of input quantities is played by external conditions and control actions, which also have a certain set of states. External influences on the unit are technological, operational and constructive factors, the number of which include soil resistance, the surface profile of the field, the physical and mechanical properties of the material being processed (soil density, soil moisture, etc.), the technical condition of the machine working bodies, and the depth of processing. As the speed of motion increases, the correlation between the sections of the random function decreases. As the speed of motion increases, the spectral density decreases, and its maximum value shifts towards higher frequencies; spread of the values of random function with respect to the mathematical expectation increases with increasing aggregate speed; by correlation functions and spectral densities, it is possible to establish the main parameters of random processes, variances, the mean square deviations prevailing in the frequency process and the corresponding periods, the dispersion distributions over frequencies that are necessary to establish the parameters of the output indicators characterizing the level of functioning of agricultural machine-tractor aggregates.

The larger the cross-sectional area of the formation can be processed in a single pass, the less energy is needed to carry out the process. The cross-sectional area of the treated formation is determined by the perimeter of the working body. The circle of all figures of equal perimeter has the largest area. It is advisable to make the working organ ring-shaped. When designing a ring on the plane of the smallest cutting force, an ellipse is formed. From the point of view of physical mathematics, the ellipse is the best curve possessing the minimum property. The optimal shape of the working body is an elliptical ring. The parameter of the ellipse corresponds to the angle of soil displacement in the longitudinal-vertical plane. The elliptical working body carries out the crumbling and separation of the layer with the removal of more solid macroaggregates of soil on the surface and the erosion-hazardous particles that remain inside the formation in the gap between them. Stresses on the working body are determined by interaction with the soil. On the base of the ellipse, the normal stress caused by the backing of the soil layer acts, and the pressure of the cutting edges of the working body affects the cylindrical surfaces. The intensity of stresses arising on the surface of the cylinder is determined on the internal crack of an elliptical shape located in a solid body under the action of a load. The greatest intensity of stresses is localized at the ends of the minor axis of the ellipse, and the smallest at the ends of the major axis. As the cracking angle increases, the stress intensity increases, and then decreases. With an elliptical shape of the working element, the stress intensity zone is wider than that of the circular cutting edge, while deformation of stretching and bending is created in the zone of lateral rounding, which is absent in the plane, and the traction resistance is reduced by 0,5 ... 1,3 kN. The degree of crumbling of elliptical working organs is 87,1 ... 98,5 % of fractions up to 50 mm, combing 1 ... 2 cm, reduction of erosion-hazardous particles 15...22 %.

The well-known working bodies for layer-by-layer soil-free tillage are characterized by high metal content, which leads to an increase in the weight of the structure and an increase in energy costs. The aim of the study is to reduce energy costs for the implementation of the technological process of layer-by-layer soil-free tillage. Due to the use of new non-metallic materials based on plastics in the design, it is possible to significantly reduce the metal capacity of working bodies and energy consumption for the process of layer-by-layer soil-free tillage. The article proves the expediency of using plastic in the structures of working bodies for soil cultivation. The choice of plastic should be based on analysis of its properties and characteristics. Tolerant to the change in the properties of the medium are high-molecular compounds of plastic with the flexibility of the polymer chain, which limits its steric hindrance to rotation and the interaction of groups of atoms. Thermoplasts obtained on the basis of branched polymers can be re-processed. These include polytetrafluoroethylene and polyethylene as the most appropriate conditions for agricultural production. The design of the working body for layer-by-layer soil-free tillage, containing a rack with a chisel, removable plowshares, crushing machine, thrust plate and ripper for small processing has been developed. In the local wear zones and areas of increased friction of the working body ultra-high molecular low-density polyethylene was mounted. The technique for optimizing the parameters of the working element for layer-by-layer soil-free tillage with the use of ultrahigh-molecular low-density polyethylene is based on the planning of the experiment on the three-factor Box plan. The smallest traction resistance and the minimum energy consumption of the working element for layer-by-layer soil-free tillage with the use of ultrahigh-molecular low-density polyethylene at a unit speed of 2.8 to 3.0 m/s are established; the angle of entry of the bit to soil from 31,5 to 33,5°; the depth of tillage is 30-35 cm.

The final verification of the performed calculations on the adequacy of the stated hypothesis on the phenomenon being studied is the experiment. Using the method of monographic examination of known bearing systems, the design of an experimental setup for conducting field experimental studies of the working organs of tillage machines was developed. When conducting experimental studies, methods of energy assessment, estimation of technical parameters in accordance with state standards, and methods of full-scale experiment using modern computer diagnostic tools and software are used. The experimental installation for studying the working organs of soil-cultivating machines of the proposed construction includes a frame, support wheels with the possibility of adjusting the depth of soil cultivation by means of a screw mechanism, the attachment mechanism, a hinged mechanism with the fastening of the test organ, the fixing mechanism of the measuring sensor and rigidly fixed to the frame of the apparatus working body to create conditions for the real technological process of functioning. When the system moves through the experimental section, the analog data of the traction resistance read from the measuring sensor is transmitted to the amplifier, from where it is fed through the channel to the analog-to-digital converter board, then the digitized data is fed to the personal computer. It is established that the relative error in the data of the experimental determination of the parameters and indices of the technological process of the working organs of soil-cultivating machines when using the proposed experimental installation with a measuring complex does not exceed 4 % of the results of theoretical studies. The experimental installation allows to carry out investigations in the field conditions with imitation of the real process of operation of the designed tiller machine.

In the layer-by-layer treatment of the soil, a moisture accumulating layer is formed inside the formation. To form a moisture accumulation layer, it is necessary to optimize the design of the ripper for shallow working of the layered working organ. The aim of the study is a comparative evaluation of the agrotechnical indices of the technological process of layer-by-layer soil-free tillage. The design of the working organs under investigation contains a rack with a chisel for deep tillage. In the front part of the rack there are removable plowshares. On the bit is fixed with the possibility of moving the crusher and the thrust plate is located. At the top of the rack is mounted with the ability to replace the ripper for shallow tillage. Experimental data on agrotechnical indices of the technological process of layer-by-level tillage of new working bodies with elliptical, planar (metal and plastic) ripper were obtained on the experimental field. Ultra-high-molecular-weight low-density polyethylene was installed on the ripper, chisel, crumbler and thrust plate of the working device for layer-by-layer soil-free tillage with plastic elements. The working bodies correspond to the agrotechnical requirements. The deviation of the depth of treatment from the preset 2,83-6,88 %, the combability was 0-7,53 cm, fractions up to 50 mm in size (76,8-98,5 %) predominate in the treated soil layer, the content of erosion-hazardous particles decreases In the surface layer by 2,90-18,13 %. The most qualitative soil cultivation was carried out by a working organ with elliptical, least - with a flat-topped ripper. To improve the performance it is advisable to give a curved shape to a flat-topped ripper made of plastic. There was a sticking of the front part of the counter of the organ. Plastic is not susceptible to sticking with moist soil and self-cleaning.

Nowadays the trend of development of combined units and devices for implementation of specified technological processes is widely spread. The use of combined working organs for graded subsurface tillage allows to reduce the energy and labor costs and to improve the technological process. Based on the comparison methods and monographic survey of existing designs of working organs, their shortcomings when using in arid conditions are revealed. It has been established that in such conditions it is advisable to apply graded subsurface tillage. The analysis of designs of working organs for graded tillage is performed, it allows to establish the advantage of curved elements for surface tillage. A number of shortcomings of subsurface cultivating working organs that have been revealed during years of researches allows for the conclusion about the prospects of replacing blades on curvilinear rippers for surface tillage. The data of content of valuable soil aggregates as a percentage of absolute dry chernozemic soil are given. Based on the analysis of the data, it is established that layer structure can be improved through the use of an element for surface tillage to the depth down to 16 cm in design of chisel working organ. The expediency of mounting of elements for deep and surface tillage on the same tine for graded subsurface tillage is proved. The scheme of a combined working organ is proposed: a chisel for deep tillage and a curvilinear ripper for surface tillage are mounted on its tine, which provides the required crumbling of layer.

The paper presents the results of experimental researches of different versions of working organs for graded subsurface tillage. Analysis of their energy and agrotechnical indicators is performed.

6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase is a key regulatory enzyme of glucose metabolism. This bifunctional enzyme controls glycolysis and gluconeogenesis as well as glucose phosphorylation and metabolism. 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-2 (PFKFB-2) plays significant role in the glycolysis regulation in the heart as well as in some other organs (kidney, brain and lung). Results of this investigation clearly demonstrated that in the glioma cells as well as in some mouse organs are presented several new unique alternative splice variants of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-2. These PFKFB-2 splice variants are a result of deletions or/and inserts in catalytic regions of 6-phosphofructo-2-kinase and fructose-2,6-bisphosphatase as well as in С-terminal regulatory region. Alternative splice variants of PFKFB-2 from glioma and mouse cells contain different inserts after 2nd exon but mouse splice variant has also deletion in 6-phosphofructo-2-kinase region and insert in C-terminus. Another splice variants of mouse PFKFB-2 have deletions in 6-phosphofructo-2-kinase or fructose-2,6-bisphosphatase regions, since one splice variant has deletion of all catalytic domains. In conclusion, this study provides evidences that alternative splicing of PFKFB-2 mRNA possibly has a significant role in glycolysis regulation via creation of monofunctional isoforms of this enzyme.

A bifunctional PFKFB enzyme is a key regulator of glycolysis. Four different genes encode the synthesis of multiple PFKFB isoforms. We analyzed data concerning structural organization of PFKFB genes and alternative splice variants of PFKFB mRNA, as well as expression and molecular mechanisms of regulation of different PFKFB isoforms in malignant tumors and at hypoxia, and mechanisms of hormonal regulation. Hypoxia inducible factor (HIF)-dependent mechanisms of regulation of the expression of different PFKFB variants are presented and discussed.

The article has investigated the properties of a diaphragm discharge created in tap water and in aqueous solutions and a possibility of using such a discharge for purifying polluted water. The diaphragm discharge whose plasma destroys the structure of water pollutants was obtained by inputting the 12 kV to the openings in a glass-cloth-base laminate diaphragm immersed in water or a solution. Oscillograms and electronic pictures of the discharge show the possibility to control its duration and power for oxidizing water purification of water of organic pollutants. It has been found that simultaneous water scavenging with air enhances the purifying effect of the diaphragm discharge.

This work is aimed at studying plasma torch formation, voltages, currents, power distribution, and resistance variation in the case of the little understood low-energy (≤10 J) diaphragm discharge initiated in water and salt solutions. Plasma torches associated with this type of discharge differ considerably from those of other discharges. Different shapes of anode and cathode torches, breakdowns between the diaphragm and one of the electrodes, and a specific form of cathode breakdown are observed. It is found that the electrical conductivity of the medium influences the parameters of the plasma formations, current pulses, dielectric strength of the medium, current pulse variation at “semibreakdowns,” etc. Based on the experimental data, it is concluded that the process of discharge initiation differs from that described in the literature.