The aim of the study was to determine impact of commercially available hydrotreated vegetable oil (HVO) and its mixture (HVO5, where 5% (v/v) HVO and 95% (v/v) FDD) with diesel fuel (FDD) on the power, torque, fuel consumption, and exhaust gas composition of an atmospheric internal combustion diesel engine used in off-road applications. Diesel fuel was used as the comparative fuel. Testing was realized in a full-load mode on the KOHLER KDI 1903 M 3-cylinder diesel engine on a SIERRA CP-Engineering engine test bench. The AVL SESAM FTIR exhaust gas analytical system was used to determine exhaust gas emissions, while the AVL KMA Mobile fuel consumption measuring device was used to measure fuel consumption. Research showed that the lowest power and torque readings were obtained with FDD, while HVO showed a slightly higher result compared to the fossil diesel fuel. At the same time, the highest hourly fuel consumption was observed running on HVO5, while the lowest was observed with FDD. Increases in carbon monoxide (CO), carbon dioxide (CO₂), and nitrogen oxide (NO_x) emissions were observed for HVO5 compared to those of FDD. The CO content in emissions increased by an average of 3.0% using HVO and by an average of 36% using HVO5, but the NO_x content in the emissions increased by an average of 3.0% using HVO and by an average of 8.8% using HVO5. The reduction by an average of 60% using HVO in emissions was found in the case of hydrocarbons (HC). Research confirmed that the physicochemical properties of HVO could leave an impact on the main engine performance parameters and exhaust emissions.

The article discusses the development problem of the professional competence of the future agricultural engineering specialists when studying the discipline “Maintenance of Machinery and Equipment.” The proposed model is based on the requirements of a social order of the society and stakeholders of the agricultural industry for highly qualified specialists who stand out by professional responsibility and readiness to efficiently and creatively perform their professional duties. The input element of our research is the goal of professional training at educational institutions of the future agricultural engineering specialists for the maintenance of machinery and equipment in accordance with the current and future needs of economic sectors and the state in the context of globalization in accordance with international requirements of technical regulation. The basis of the research are the theoretical (comparative analysis of scientific, methodological and pedagogical literature) and the empirical (observation, analysis and generalization of pedagogical learning experience) methods. There are determined and theoretically substantiated the psychological and pedagogical conditions for the implementation of the developed models in the process of studying these disciplines. The efficiency of the developed logical models, and their impact upon the components of professional competence, carried out through the use of approaches to the acquisition of scientific knowledge, the use of integrative learning technologies, as well as increasing cognitive activity, motivates students to study the discipline of maintenance of machines and equipment.