An electrostatic air cleaner is highly efficient for air clearing, which allows blocking dust, tiny particles and bacteria. However, the cost of such devices is quite high; for example, the increase of the degree of cleaning by 6 % raises the relative value almost 3 times. As a result, it restrains their distribution in agriculture. The solution to this problem is possible by upgrading the design of the electrostatic air cleaner, which consists in science-based choosing the area of the collecting electrode. The standard research methods were used for the experiment: the method of multifactorial experiment, statistical analysis, determination of the adequacy of the experimental data. Several collection electrodes have been studied in the form of tubes with different inner surface, so that their area corresponds to the analytical values: smooth surface, corrugated surface, undulated surface, complex surface with interleaving niches and crowns (like cuts in firearms). As a result of the experimental studies the dependence of the degree of cleaning of the electrostatic air cleaner η on the speed of the particle movement to the collecting electrode ν and supply air w at a constant square area of the collecting electrode is found. The maximum degree of air cleaning from bacterial pathogens varies from 60 to 99 %. The use of air cleaning installations in conjunction with recirculation allows reducing the gas content in the room, where animals are kept, for 6 times; the number of pathogenic bacteria (coliform bacillus, staphylococcus) is reduced 10 times; the amount of the consumed electric power to maintain the microclimate is reduced 2 times; the young stock loss is decreased from 40 % to 5 %.

Modern techniques of potato tubers storage have a number of economic, technical, and technological disadvantages and they do not ensure high product safety-potato losses run up to 30 % per storage season. The main goal of the experiment conducted by the authors is a research investigation of the impact made by electrophysical methods on reservation capacity of potato tubers, because this method is the most interesting and understudied. During the experimental studies potato tubers were exposed to electromagnetic direct-current field, electromagnetic alternating current field, ionization, microwave field. The equipment used in the research: equipment for magnetic potato treatment, a microwave field generator, a generator of air ions, DC and AC voltage sources, and auxiliary instruments. As a result of the experimental studies it has been found that untreated potatoes had mass loss of 39 %. Mass loss of potatoes treated with microwave field was over 50 %. Potatoes exposed to aeroionization lost 23 % of their mass. At a magnetic treatment dose of 6-8 mT⋅s mass loss of potatoes does not exceed 20 %, but when a dose of magnetic treatment is greater or less than the specified ranges, mass loss of potatoes exceeds 40 % reaching 75 %. Hence it has been demonstrated that the method of electromagnetic treatment within specific ranges is the most economical one. According to the results of the experiments, electromagnetic potato tubers treatment at a dose of 6-9 mT⋅s has been recognized as the most effective option.

The article presents a method for calculating the magnetic system using the finite difference method for the axisymmetric system. The finite difference method for constructing a model of the generator's magnetic field allows integrating differential equations into partial derivatives by reducing the equations in finite differences. A special feature of the presented calculation method is the automation of determining the boundaries of the media interface, by taking into account the magnetic resistance of adjacent nodes relative to the calculated node. The main characteristic of a magnetic field is magnetic induction, which is a vector quantity. Magnetic induction is calculated based on the distribution pattern of the magnetic potential. Based on the Poisson and Laplace equations presented in the article, a computer program was developed for automating the calculation of the magnetic induction vector. The results of the program for calculating the magnetic field pattern on the example of a synchronous generator with a two-circuit magnetic system used as a part of a wind generator are presented. Graphical dependences of the change in the value of magnetic induction inside the stator coil of a synchronous generator are constructed for a rotor with an external magnetic circuit, for a rotor with an internal magnetic circuit, and for a rotor with two magnetic circuits simultaneously. In the calculation of the magnetic system, as presented in article, by the method of the example synchronous generator with dual magnetic system, the maximum value of magnetic induction, penetrating the winding of the synchronous generator along the axis r, when the internal circuit is 0.21 T, using the external loop, the value of the magnetic induction vector is 0.283 T. When using a two-circuit system, the value of the magnetic induction vector is 0.483 T.

The article describes a method for increasing the efficiency of using solar panels when using a two-axis system for tracking the sun. A mathematical model of solar panel operation has been developed for the following applications: stationary installation of solar panels and the use of a two-axis solar tracker. The solar tracker has the ability to rotate the solar panel by the azimuth angle from 0 to 170 degrees, by the Zenith angle from 0 to 90 degrees. The paper presents a method for calculating power generation by solar panels using a solar tracker and a variant of stationary installation of solar panels. Plots of the PV panel as a function of time at stationary position of the solar panels and using a solar tracker. As a result of mathematical modeling, when using a solar tracker, compared with a stationary installation of a solar panel, electricity generation increases by 89.9% on the example of June 22, and by the example of December 22, the increase in electricity generation is 19.6 %. Using a solar tracker during the year increases the efficiency of electricity generation by solar panels by an average of 45-55%. Data on azimuth angles of sunrise and sunset, as well as the Zenith angle depending on the time of day for the 22nd day of each month are given in the table below. The results obtained are presented for coordinates: 45 degrees 3 minutes North latitude 41 degrees 59 minutes East longitude, which corresponds to the locality of the city of Stavropol in the Russian Federation.

Abstract. The article discusses pressure variation in the interwall camera of the milking machine during the milking process. Some patterns are offered for determination of duration of the change of pressure in the interwall camera of a milking cup. A conclusion is drawn for the necessary duration of the change of pressure in the interwall camera of a milking cup. The principle of operation of the modern milking machine is based on periodic interaction of mamillar rubber and vacuum on the animal udder. The duration of the change of pressure in the interwall camera is the main characteristic, which provides an indication of the impact of the milking machine on the animal udder. The modern developments of animal physiology have provided the necessary knowledge on the basis of which the main features of milk processing and the biological requirements for milking are revealed and formulated. Taking into account these features, it is possible to claim that the transition phase from a sucking step to a compression step in the interwall camera of a milking cup will be more smooth and long-lasting. Thus, it is necessary to improve constructions of milking machines for creation of an opportunity to regulate the duration of transitive phases in the interwall camera of a milking cup. It will help avoid the negative impact of the milking machine on the organism of animals in the course of milking that will increase productivity of cows and quality of the received milk.