Belarusian State Agrarian Technical University

A special feature of the existing relay protections of power transmission lines (PTL) is their operation on an already existing damage in the electrical network, when the short-circuit current already acts on the primary equipment and on the parameters of the entire electrical network, and when approaching an unacceptable distance to the line of people passes through the human body. To date, there are no relay protection devices capable of shutting down PTL before an emergency or abnormal line operation occurs: when people, mechanisms, or trees approach it at an unacceptable distance. The practical issue of creating a fundamentally new relay protection trigger (RPT) based on measuring high-frequency current in phase wires of PTL is considered. Mathematical modeling of three-phase operation and experimental study of single-phase relay protection triggers in case of emergency and abnormal operating modes on a 50 m long transmission line section were performed. Mathematical modeling was performed in the MMANA GAL Basic V.3.0.0.30 program for the following operating modes: normal, emergency (with single-phase, two-phase and three-phase short circuits), abnormal (interruption of any phase, approaching an unacceptable distance to PTL wires of current-carrying devices). As a result of experimental studies, quantitative indicators of changes in the parameters of the high-frequency current generated in the phase wire during short circuits, approaching the wire of a conducting object and wire breakage have been determined, which can be used as an input signal for triggering the developed circuit. The creation of a new RPT and its use in relay protection terminals of PLT will make it possible to disable both “classic” emergency and abnormal operating modes of lines, as well as damage caused by people and objects conducting electric current approaching an unacceptable distance.

A logistic regression analysis of production risks during the operation of mobile agricultural machinery (using forage harvesters as an example) was performed. The logit transformation of risk as a one-dimensional value described by probability was considered, and the resulting dependencies were tabulated.

The article presents the results of a comparative study in the southern agroclimatic zone of Belarus in the taxonomic series of 6 new introduced varieties of highbush blueberry: early ripening – Chanticleer, Hannah’s Choice, midseason – Bluegold, Harrison, and late ripening – Aurora, Rubel, as well as the corresponding to these maturity groups zoned varieties Weymouth, Bluecrop and Elliott structures of correlation links between the levels of antioxidant and enzymatic activity, on the one hand, and 12 indicators of biochemical composition, on the other.Significant genotypic differences in the orientation and strength of these links were revealed due to the individual characteristics of the biochemical composition of the tested objects, indicating a pronounced variety specificity of the analyzed traits.A noticeable similarity was revealed in the representatives of different varietal groups in the spectra of organic compounds most significant for formation of the antioxidant complex of fruits, which was most clearly manifested in early and late ripening varieties and consisted of the dominant role of catechins, tannins, leucoanthocyanins and flavonols, and in midripening varieties – along with tannins and leucoanthocyanins, also free organic and hydroxycinnamic acids.At the same time, soluble sugars and ascorbic acid had the least effect on the antiradical properties of blueberry fruits. A uniform sequence of blueberry taxa was established in the order of decreasing the interaction level of individual components of the antioxidant complex of fruits with the content of organic compounds of different chemical nature with the greatest manifestation of the strongest direct correlation links with sources of antioxidant, peroxidase and polyphenoloxidase activity in the Hannah’s Choice variety, and in the Aurora variety – with sources of catalase and, to a lesser extent, the peroxidase activity against the background of a minimum number of such interactions in the Harrison variety, which was 1.6–2.1 times inferior in this feature to the leading blueberry taxa.

The concept of the discriminant of a quadratic polynomial allows for easy extraction of information about its real and complex roots. The discriminant of a polynomial of an arbitrary degree is also an important characteristic of the polynomial, which proves useful in many problems in the theory of Diophantine approximation. In 2023, Belarusian mathematician D. Badziahin solved a problem posed by Davenport in the 1960s concerning the range of values of discriminants in the cubic case. The paper provides a complete solution to the problem of divisibility of discriminants by large powers of prime numbers in the case of cubic polynomials.

The development of restoration technology and meadows, improvement of run-down pastures, and productivity improvement of old crops of perennial grasses is an urgent problem in agriculture. The tillage traction force in seeder designing and manufacturing is an important indicator of energy efficiency. The objective of this work is to reduce traction force and ensure seeding depth uniformity by justifying the optimal chisel parameters of a grain–fertilizer–grass seeder for direct seeding in sod. The Box–Behnken method was applied to investigate the traction force dependence on the seeder velocity, seed embedding depth, chisel width, and mounting angle. The obtained optimal parameters of coulters were justified by the finite element method. Structural and technological parameters were checked using the smoothed-particle hydrodynamics method on the deformation and wear of the seeder working body. The revealed optimal coulter parameters were as follows: chisel width was 20–20.97 mm, chisel length was 145–148.9 mm, mounting angle was 75°–81.6°, and achieved minimum traction force was 720 N. These parameters ensure the quality of grass seed embedding in the sod. The theoretical data of traction force (8.27–8.39 kN) are in accordance with the experimental (8.28–8.63 kN) data under field conditions. These findings are efficient in agrotechnical and mechanical predictions regarding the occurrence of chisel residual stresses and the working lifetime of the part.

Information is provided on the current state of the grain subcomplex in Belarus, in particular the Minsk region. The necessity of further development of high-tech agroindustrial production of a full cycle of in-depth processing of key grain crops on the basis of the Belarusian National Biotechnology Corporation is substantiated. This can help to increase the profitability of the main farms of the Minsk region.

A method for reducing the resistance of the ground loop for high-resistance soils by using mixtures based on hydrogel is considered as backfill materials. Based on the results of the research, an analysis was made of the effect of mixtures on soil resistivity, the seasonality factor and the resistance of the ground loop at various temperatures and humidity.

The development of agriculture in the Russian Federation and the Republic of Belarus includes implementing «smart systems» in agriculture based on modern wireless, intelligent technologies and the Internet of Things. This survey presents related works published in the last decade on the use of the Internet of Things to develop agriculture. The survey is based on publications from the scientific electronic library eLIBRARY.ru. We categorized the publications according to the areas of agricultural production as follows: animal husbandry, crop production, greenhouses and weather forecast, water management and irrigation, machinery management, mapping and geodesy, and digital platforms. The survey shows that in Russia and Belarus IoT technologies are developing in agriculture intensively as in advanced countries.

The article presents results of our experiments carried out to study the invariance of the digital description of the imageThere in the paper is formulated a mathematical problem of multi-hypothetical detection of subclinical and clinical mastitis in dairy cows by the maximum values of udder temperature measured by digital processing of the udder thermal images. The optimal temperature threshold values corresponding to the Bayesian criterion of the minimum average risk in the above multi-hypothesis detection problem are determined by numerical modelling.