Volume 34, Nº 4 (2024)

Introduction. Vegetable growing is one of the most important branches of agricultural production. Production of vegetables is carried out in both agricultural enterprises and on personal subsidiary and individual peasant farms. Growing vegetable crops on personal subsidiary and individual peasant farms involves tillage: plowing, cultivation, milling, etc. For tillage, there are actively used small tools, in particular tillers. The experience of their use and the research on the effectiveness of their functioning allow identifying ways to improve tillage quality.
Aim of the Study. The study is aimed at identifying the hardness of medium-loamy gray forest soil on different soil horizons typical for growing fruits and vegetables in personal subsidiary and individual peasant farms.
Materials and Methods. To measure the soil hardness, there are used different types of penetrometers: percussion, statically loaded and forcibly pressing a deformer (cone, cy­linder, and ball) into the soil. In the study, instruments and devices for measuring the soil hardness were analyzed. The scheme of the soil hardness analysis included measurements after harvesting the following crops: potatoes dug using a motor cultivator with a passive potato digger, potatoes dug with a hand tool (shovel), fodder beets, squashes, and common onions. The soil hardness was measured using a hardness tester (penetrometer) manufactured by Wile Soil.
Results. The use of hardness testers in personal subsidiary and individual peasant farms is difficult due to their high cost and to the fact that the most part of these devices are specialized laboratory equipment, which require specific skills when used. Analyzing the soil hardness on personal subsidiary and individual peasant farms in the post-harvest period is a relevant task for optimal functioning of tillers, namely, it will allow operators to use the most efficient modes for tillage that will increase the tillage unit performance. 
Discussion and Conclusions. Based on the analysis of the results of the experimental stu­dies, there have been obtained the regression equations that allow determining the value of the hardness of medium-loamy gray forest soil from a depth (up to 20 cm) in the period after harvesting crops, which are the most common for growing in personal subsidiary and individual peasant farms of the Republic of Mordovia.

Introduction. The agricultural sector is one of the most important sources of anthropogenic emissions. The correct accounting of greenhouse gas emissions in this sector depends on technologies used to process animal/poultry manure. To date, there is a lack of research to adjust the methane and nitrous oxide emissions from existing animal/poultry manure sto­rages, because of the variety of technologies used. This is why the methodological approach developed to estimate the annual emissions of methane and nitrous oxide is so important.
Aim of the Study. The study is aimed at determining the impact of manure and litter processing technologies on annual emissions of methane and nitrous oxide.
Materials and Methods. To determine the emission of nitrous oxide and methane, there were calculated mass of animal/poultry manure and its total nitrogen and carbon content; there were analysed manure processing technologies such as long-term manure storing, passive and active composting, biofermentation, drying and granulation, incineration. There were performed calculations for two options: 1) according to the National Inventory of Anthropogenic Emissions, taking into account the share of manure processed with the use of each technology in 2022; 2) according to the actual data of technology distribution in 2022. The predictive estimate for the period up to 2030 was made for regions in the North-Western Federal District of the Russian Federation.
Results. The study analysed animal and poultry housing technologies at three types of enterprises: agricultural organizations, peasant (private) farms, and household farms. There was calculated the animal/poultry manure mass generated at each type of enterpri­ses and determined the share of manure processed with the use of each technology. Based on the data of the North-Western Federal District, there were calculated methane and nitrous oxide emissions in 2022 in CO2-eq.
Discussion and Conclusions. There was estimated the effect of manure collection and sto­rage technologies on methane and nitrous oxide emissions. The obtained data on emissions exceeded by 35.6% (methane) and 14.2% (nitrous oxide) those calculated by the methods used in National Inventory indicating their refinement expediency. Categorization of agricultural enterprises makes calculations simpler for regional and national assessments. The refined data on manure collection and storing technologies and the emissions specific for these technologies will help to perform prediction calculations and determine options for technological upgrading to mitigate GHG emissions.

Introduction. The high demand for polymer products creates the need for constant mo­dernization of the technological aspects of their production, increasing the efficiency of which is impossible without a model description and solving problems of optimization of its main technological stages. The current needs for manufacturing the products with a specified structure and properties make the issue of creating tools for solving optimization problems very relevant. One of the tools for controlling the product molecular weight is using the fractional mode to supply a regulator, the composition and dosage of which are often selected empirically.
Aim of the Study. The aim of the study is to develop methods and algorithms to determine the mode for multipoint supplying a regulator in the continuous-running manufacturing of polymer products with specified molecular characteristics.
Materials and Methods. To choose the optimal regulator supply mode, there is used a heuristic method represented by a genetic optimization algorithm. This algorithm is based on the mechanism for creating a population of potential solutions that are subjected to the operations of crossing, mutation and selection imitating the processes of inheritance and evolution in nature. To assess the molecular characteristics of the copolymerization pro­duct, there is applied a kinetic modeling approach based on the use of molecular weight distribution moments. For a mathematical description of continuous-running production, there are used recurrent relations characterizing the transfer of the reaction mass between ideally mixed reactors.
Results. According to the conditions for organizing continuous-running manufacturing, it is possible to add a regulator at the beginning of the process in the third and sixth poly­merizers along the battery. In order to determine the regulator supply mode, the optimization criterion was developed in the form of a functional reflecting the absolute difference between the calculated and specified values of the number-average and mass-average molecular weights. The software implementation of the developed method and optimization algorithm, and the computational tests carried out made it possible to identify a number of solutions, each of which contributes to manufacturing a product with specified molecular characteristics. Visualization of some resulting solutions demonstrates different molecular weight dynamics throughout the process.
Discussion and Conclusion. Through using the developed method and algorithm, there has been solved the problem of identifying the three-point molecular weight control regime for the continuous-running process of producing styrene-butadiene copolymer. The choice of a genetic algorithm for the study and optimization of complex multifactorial physicochemical systems is justified by the fact that it allows searching for one or more system parameters in both a discrete and continuous set of variables and contributes to finding a global optimum due to the random nature in the search for solutions. The variety of solutions obtained for the problem makes it possible to control the process of polymer synthesis in the case of constant monitoring of the physicochemical characteristics of the product.

Introduction. Homogenization is one of the most significant factors ensuring the successful implementation of the technology for manufacturing various dairy products. During this process, there are changed the properties and structure of proteins. In particular, there is decreased the size of casein micelles, which break down into submicells. After that, the accumulation of submicells on the surface of fat particles is likely. The increase in the homogenization pressure amplifies the mechanical effect on the particles, therefore, the average size of fat globules decreases. 
Aim of the Study. The study is aimed at reducing energy costs for manufacturing dairy products while ensuring the maximum preservation of the quality of dairy products. 
Materials and Methods. There has been studied the influence of homogenization pressure on the process technical parameters such as the power used for the homogenizer drive and for the dynamics of changes in the product properties during storage. The analytical dependences describing the main parameters of homogenization are considered.
Results. Compliance with the recommended homogenization parameters and other para­meters, in particular heat treatment, can significantly increase the product shelf life without significant changes in the initial quality indicators. If the process conditions allow crushing the initial fat particles to a size of about 1.0 micrometer and distributing them evenly throughout the volume, it makes possible to get a significant improvement in the taste and consistency of the resulting products. There has been studied influence of homogenization parameters on the shelf life of yogurt manufactured according to the proposed formula with using southern fruits, in particular, with dogberries. 
Discussion and Conclusion. Taking into account the results of experimental studies, we have concluded that the energy costs are significantly affected by the homogenization pressure (absolute value) and the ratio of pressure values at various stages of homogenization. The product manufactured according to the proposed formula with crushed dogberries preserves good taste, microbiological properties, and physical and chemical specified parameters for 14–15 days. It follows that the shelf life of yogurt manufactured according to the proposed formula should not exceed more than fourteen days at a temperature of no more than +6 °C.

Introduction. Electrolytic deposition of nanoparticles is gaining interest with their increasing demand for restoring surface layers of machine parts and mechanisms. To create composite coatings with nanoparticles, it is necessary to solve two main tasks: to ensure a sufficient number of particles in the coating and to prevent their agglomeration in the coating solutions.
These coatings with nanoparticles are wear-resistant and are used, for example, in automobile and tractor engines. In this study, there are considered the process of electrolytic production of composite coatings based on a nickel matrix with micron-sized and submicron-sized silicon carbide (SiC) particles from Watts nickel solutions and the resistance of nickel composite coatings to sliding wear.
Aim of the Study. The study is aimed at considering detailed the effect of the size and number of particles in the coating solution on the number of codeposed particles. It is also necessary to study how the particle size affects the codeposition of micron-sized and submicron-sized particles of the non-Brownian type.
Materials and Methods. A conventional nickel-plating electrolyte was used for nickel-based composite coatings with SiC. There was measured particle number density for each coating solution. It was assumed that the particles had the same size and shape of a sphere.  The concentration of particles in the coating solutions ranged from 0.28 to 104 g/l. Electrodeposition was carried out on vertical electrodes, and the coating solution was stirred with a magnetic stirrer during electrodeposition. The Vickers microhardness with a load of 30 g was measured and wear tests were performed for unidirectional and bidirectional sliding.
Results. The results of studying the wear resistance of nickel composite coatings during sliding have been obtained. The results of codeposition and a model based on the density of codeposed particles are presented. There has been made the conclusion about effect of codeposed particles on the wear resistance of Ni-SiC composite coatings. 
Discussion and Conclusion. It was determined that the best sliding resistance was obtained using Ni-SiC composite coatings containing 4–5 volume percentage of submicron-sized SiC particles. The study showed that the size and density of SiC particles in the coating solution are important for producing galvanically wear-resistant composite coatings, based on the relationship between the density of deposited particles and the density of particles in solutions.

Introduction. The magnetic systems of high power microwave generators, such as relati­vistic reverse wave lamps and klystrons, are powered with a direct current of up to 1 000 A from supercapacitor storage for several seconds. When designing power supplies for these magnetic systems, there is always necessary to determine the energy characteristics of the storage device. The analytical calculation of the characteristics is difficult, because of dynamic changes in some parameters of the magnetic system and storage device during current flow.
Aim of the Study. The aim of the article is to create and experimentally test a mathematical model describing the process of powering a multi-section magnetic system with direct current from a supercapacitor storage device.
Materials and Methods. The simulation takes into account the dynamic changes in the magnetic system parameters when current flows. The supercapacitor storage device is represented as a simple RC-circuit, the parameters of which are the nameplate data of its capacitance and internal resistance. The description of a storage device discharge process is based on the energy balance data. This model is implemented in the National Instruments LabView 2012 software package and has a user-friendly graphical interface. The simulation results were tested on equipment consisting of a power supply based on a supercapacitor storage device and two-section magnetic system.
Results. The simulation results showed a good agreement with the experimental ones. According to the experiment results, the waveform of the current and voltage of the sto­rage device, and the maximum duration of current stabilization were close to the simulation results. At the same time, the nameplate data of the capacity and internal resistance of the storage device characterize well its real parameters, taking into account the peculiarities of working together with the current regulator and the pulsed nature of energy consumption.
Discussion and Conclusion. The slight difference in the results is explained by the deviation of the actual parameters of the storage device from its passport data and by the diffe­rence in the temperature of the windings used in the experiment and simulation. The calculation of the energy characteristics of the storage device is performed on the basis of the energy balance, which allows scaling the load through adding any number of energy consumers with independent current stabilization in each.