Existing occupational risk assessment methodologies often fail to sufficiently account for objective factors that influence risk realization. Consequently, there is a critical need to revise the conceptual approach to assessing risks for tractor and agricultural machinery operators. The study aims to identify overlooked occupational and environmental factors to enhance the accuracy and quality of risk assessments. The methodology is based on a comprehensive synthesis of research regarding the impact of workplace conditions and human factors on safety. The study demonstrates that risk levels are significantly influenced by investments in occupational health and safety (OHS) measures, as well as the presence of environmental stressors – such as excessive noise and extreme cabin temperatures – that accelerate fatigue and impair attention and reaction speeds. Findings show that an increase in workplace temperature to 26-28°C reduces operator performance by 20-25%. Conversely, poorly regulated air conditioning (temperatures below 20°C) also increases fatigue and accident risk by 15-20%. Similarly, every 10 dB increase in noise level leads to a proportional rise in fatigue and a decline in productivity. To address these “risk intensification factors,” the authors propose the use of correction factors in hazard coefficient calculations. These factors account for the impact of environmental stressors, operator age, and other variables on fatigue. The proposed framework provides a scientific basis for refining occupational risk assessment methods and improving the reliability of safety evaluations for tractor and machinery operators.

Animal by-products are additional outputs of the main farm production. They should be integrated into the closed cycle of agro-ecosystems to restore the fertility of farm land. The aim of the study was to develop a comprehensive approach to the use and pre-application treatment of manure in the form of animal by-products. The study analyzed the current challengesin the processing and application of animal/poultry manure as organic fertilizer in different regions of the Russian Federation. The authors analyzed the quantity and quality of animal by-products, technologies and equipment available in the regions, laws and regulationsrelating to the assessment of the man-made environmental impact, and the state of environmental monitoring. The study found that the annual volume of animal by-products formed in agricultural organizations and available for processing and fertilizing application was above 250 million tons. While the use of organic fertilizersin 2022, for example, amounted to only 70.3 million tons. This could be due to the lack of equipment and technologiesin agricultural organizations, and the underdevelopment of the animal by-product industry. The authors believe that the considered industry should apply the best available manure processing technologies, high-tech engineering systems, digital monitoring of production processes, and intelligent digital tools for on-farm environmental control. Thislist may also include adaptive measures of economic support for agro-ecological activities and relevant eco-standards for environmentally safe technologies, machines and equipment. The above proposals will add at least 350 million tons of high-quality organic fertilizers to domestic agricultural production and reduce the negative balance of nutrients by at least 2000 thousand tons of NPK.

The conventional system of maintenance and repair of hydraulic systems in technological (or industrial) machines cannot predict sudden failures. Transition to condition-based maintenance requires developing a methodology for real-time detection of defects in parts and assemblies. The condition of hydraulic system components can be more effectively assessed with the vibration analysis. The research aimed to develop and test a methodology for vibration diagnostics of hydraulic systems in technological machines based on the spectral analysis of the spectral power density of a vibration signal. The proposed methodology includes the following stages: obtaining raw data from sensors of the monitored mechanisms; preliminary data processing and feature selection to reduce the dimensionality of the raw data and obtain useful information from the signal; SPM-analysis and calculation of the peak factor and kurtosis; diagnostic classification of faults, defect identification; and real-time data visualization. The authors have developed a software package for automated processing of vibration signals. The analysis based on measuring the spectral density of vibration signal power demonstrated the effectiveness of defect identification under various operating modes. The methodology was tested on an NSh-32A gear-type hydraulic pump at three operating modes: 1000, 1500, and 2000 rpm. Informative features were detected from the vibration signal for diagnosing four pump conditions (serviceable, worn bearing, worn gear, and combined defects) with an accuracy of 90 to 93%. The developed methodology for controlling the hydraulic systems of technological machines can diagnose sudden failures with high accuracy. Future research plans to establish the relationship between the change in vibration acceleration and the volumetric efficiency of the gear pump.

This paper investigates the airflow distribution in a stationary porous grain bulk. The aim of the study was to develop a mathematical model for a ventilated stationary porous layer, analyze airflow dispersion, and compare the results of CFD (Computational Fluid Dynamics) simulations with experimental data. The modeling was performed using SolidWorks software, while experimental measurements were conducted in a specially designed test stand. To assess the accuracy of the developed model, a statistical analysis was carried out using an independent two-sample ttest and Fisher's criterion. The experimental and simulation results showed strong agreement, with no statistically significant difference detected between their variances (p < 0.05). The findings confirm that the developed mathematical model accurately represents airflow behavior in the stationary porous grain bulk. The simulation results allow for a more detailed visualization of airflow distribution, identifying zones of excessive flow and stagnation. These insights contribute to optimizing ventilation system efficiency, reducing energy consumption, and improving grain storage conditions.

Abstract The efficiency of the existing technologies for pre-sowing seed treat-ment, ensuring the high quality of seed material along with its proper clearing and sorting, has been analysed. One effective solution is the introduction of electrical technologies, the complexity of which lies in the scientific sophistication and the variety of tasks they address. The authors propose an electrotechnological complex (ETC) for pre-sowing seed treatment, which includes a working chamber, where charged grain is fed, while aerosol is delivered through adjustable sprinklers directed toward the seed flow, allowing for control over the spray stroke length. When the freely falling charged seeds enter the cloud of oppositely charged aerosol, they become intensively coated with the working solution. The degree of coverage depends on the length of the working chamber, the potential difference between the grain flow and the sprinklers, and the concentration of the aerosol cloud. Given the relative complexity of the process and the presence of multiple disturbances, optimisation can only be achieved through automation. The main objective of the paper is to study the stability and functional quality of the automated ETC for pre-sowing grain treatment with aerosol. To achieve this, a structural and functional algorithmic scheme has been developed, outlining the composition of its elements, signal direction, and the functional purpose of each component. This scheme facilitated the development of a system simulation model. The paper presents calculated results for key performance indicators of the ETC, with values aligning with those typical for this class of systems. A key advantage of this research is the proposed system for optimal correlation of all element characteristics and parameters of the automated object, ensuring stability and high performance.

Abstract This study focused on the thin-layer drying of yam by infrared-assisted heat pump drying to determine the thin-layer drying model, the effective moisture diffusivity, and the activation energy of moisture within the yam. The thin-layer drying experiment was conducted with input drying parameters such as drying temperatures of 40, 45, and 50°C, drying air velocity of 2.5 m·s⁻¹, and infrared power of 250, 300, and 350 W. In order to determine a suitable thin-layer drying model for describing the yam drying process, six different thin-layer drying models (Lewis, Page, Modified Page, Henderson and Pabis, Wang and Singh, and Midilli) were chosen for nonlinear regression with the experimental drying data. The Midilli model was found to be the most suitable drying model for describing the thin-layer drying of yam. The average effective moisture diffusivity was in the range of 4.184×10⁻⁹ to 8.142×10⁻⁹ m²·s⁻¹, and the activation energy was in the range of 16.78 to 21.01 kJ·mol⁻¹ over the proposed range of drying input parameters

Conditions of agricultural machinery operation necessitate improving the operational characteristics and service life of parts. Polymer composite materials, unlike metals, are not subject to corrosion and have a long service life. Research was conducted to determine the influence of the type and concentration of a diluent on the rheological and technological properties of epoxy composites intended for manufacturing the exterior parts of agricultural machinery. Special attention was paid to studying the effect of the diluent on the viscosity and microstructure formation of the composite. Epoxy resin ED20 was used as the polymer matrix, and the filler was an emulsion glass mat EMC450-1250-E. Two types of diluents were investigated: inactive (white spirit and solvent 646) and active (DEG-1). The viscosity of the mixtures was measured according to GOST 25276-82 using a rotational viscometer. The porosity of the composite was determined by a multi-parameter microscopy method. The authors studied the relationship between the viscosity of ED-20 epoxy resin and the addition of active and inactive diluents at 5, 10, and 15 wt.%. As a result of the research, the active diluent DEG-1 was selected. An analysis was conducted of the porosity in the composite material based on epoxy resin and glass mat with 5, 10, and 15 wt.% of the DEG-1 diluent. Experimental results showed that the introduction of DEG-1 significantly reduces the resin viscosity, facilitating better penetration into the fibers of the filler. The optimal concentration of the DEG-1 diluent was determined to be 10 wt.%, which provides a 60% reduction in resin viscosity, uniform distribution in the glass fiber matrix, and minimal porosity in the composite material (30 pores/cm²). For manufacturing polymer composites for exterior parts of agricultural machinery, it isrecommended to use the DEG-1 diluent at a concentration of 10 wt.%.

Wheat grains are a valuable and most consumed food product, therefore, their enrichment with iron ions will make up for the deficiency of this trace element in the human body. In order to enrich wheat grains with non-heme iron (Fe3+), they were ultrasonically treated in an iron sulfate solution. Grain was saturated with iron on a Vilitek VBS-6D ultrasonic unit at a frequency of 40 kHz. Wheat grains were immersed in a bath with an iron sulfate solution in a ratio of 1 to 3. The treatment duration varied from 10 to 30 minutes in 5-minute increments. Thus, five samples were obtained. The sample with the shortest ultrasonic treatment time was selected as a control. Qualitative and quantitative evaluation of the grain after its cavitation treatment involved physical analysis methods such as electron paramagnetic resonance (EPR) and electrical impedance. The spectra were obtained on a Bruker Elexsys E580 spectrometer in the X-band. To make further analysis of the dissolution of iron ions in grain, the authors used the method of impedance spectroscopy in the frequency range between 1 Hz and 100 MHz. Based on the data obtained, they found that the introduction of iron ions leads to the greatest change in the real and imaginary components of the electrical impedance in the frequency range above 1000 Hz or in the β-dispersion region. This fact indicates good permeability of iron ions into the cell from the intercellular region through their insulating membrane. Further research will make it possible to develop an express method for determining the presence of iron ions in cereals.

Abstract Water deficiency is one of the major factors that limit crop production among those causing plant stress. Therefore, the study aimed to investigate the effect of metabolically active compounds on reducing the negative effects of drought and stimulating physiological and biochemical processes in the spring wheat variety Provintsialka. In the study, wheat seeds were soaked in solutions of substances: PEG-6000 (EG); PEG-6000 + vitamin E (PEG+E); PEG-6000 + ubiquinone-10 (PEG+Q); PEG-6000 + methionine (PEG+M); PEG-6000 + parahydroxybenzoic acid (PEG+P); PEG-6000 + MgSO4 (PEG+Mg); PEG- 6000 + vitamin E + ubiquinone-10 (PEG+EQ); PEG-6000 + vitamin E + methionine + parahydroxybenzoic acid (PEG+EMP); PEG-6000 + vitamin E + methionine + parahydroxybenzoic acid + MgSO4 (PEG+EMPMg). The wheat seeds were then poured into a 12% PEG solution to simulate the water deficit and then germinated. The study determined the activities of ascorbate peroxidase and catalase, as well as the content of ascorbic acid and glutathione. It was found that the treatment of spring wheat seeds of the Provintsialka variety with meta-bolically active compounds and their combinations affected the activity of antioxidant protection enzymes in water-deficient conditions. Treat-ment of seeds with MgSO4 solution most effectively reduces catalase activity compared to the indicators of seedlings whose seeds were in simulated drought conditions. The treatment of wheat seeds with vita-min E most effectively stimulated the activity of ascorbate peroxidase, increasing it by 65.5% compared to the control and by 2.4% relative to the PEG treated seedlings. A decrease in the activity of catalase corre-lates with an increase in the activity of ascorbate peroxidase and indicates the compensatory effect of the enzymes of the antioxidant system. The treatment of wheat seeds with ubiquinone-10 (PEG+Q) most effectively increased the ascorbate content in seedlings by 46.3% compared to seedlings whose seeds were in water deficit conditions. An increase in the ascorbate content in wheat seedlings was also noted when wheat seeds were treated with EMP (PEG+EMP) and EMPMg (PEG+EMPMg). The highest levels of glutathione in drought-stressed seedlings were observed in those treated with vitamin E and EMP (PEG+EMP), exceeding control levels by 31.4% and 30.7%, respectively, and PEG-treated seedlings by 59.9% and 59.2%. This confirms the promising use of metabolically active substances for plant adaptation under conditions of slow water flow.

The digital twin of a technological machine can significantly improve the efficiency of operation and service of farm machinery. The authors carried out theoretical studies to identify the effectiveness of using digital twins in terms of the technical condition of agricultural machinery. The article considers a possibility of using digital twins of technological machines during their operation and maintenance to automate repair inspections, digitize engineering information on maintenance and repair, minimize equipment downtime, and ensure quality control and the safety of operation. The authors present a functional dependency formula of the efficiency of using digital twins in operation and maintenance. It is established that reasonable decisions on maintenance and repair of equipment can be made only in case of digital twin modeling of various full and partial failures, taking into account operation modes, environmental impact and the wear intensity of parts. Therefore, the authors proposed to install RFID tags and monitoring terminals based on GPS, ISOBUS and modern software. They can analyze in real time information on the compliance of the process indicators to the specified parameters, and give instructions and control actions to the machine operator to correct the operation of tractors, working tools of implements, and units. Studies have shown the effectiveness of using digital twins of agricultural machinery as they can reduce costs for maintenance, elimination of failures, and unplanned downtime, as well as increase productivity.