Kharkiv Petro Vasylenko National Technical University of Agriculture

The paper deals with the development of a vibration-based technique for assessing quality and detecting design and manufacturing defects of tractor gearboxes. It highlights full-scale experimental studies of vibro-diagnostic characteristics of tractor gearboxes including carrying out vibration measurement and spectrum analysis; identifying statistical limit values of structural vibration parameters and their dependence on the technical condition of tractors; and comparing the vibration characteristics with acceptable vibrations which do not affect the acceleration of the process of tractor gearbox wear. All studies were conducted for tractor gearboxes of wheeled tractors T-150K, KhTZ-170, and T-17221 produced by Kharkiv Tractor Plant and equipped with identical tractor gearboxes of the same manufacturer. It has been determined that the vibration levels of gearboxes at the manufacturing stage exceed the acceptable vibrations by 10–30 dB. The main reason for the accelerated development of faults and decrease in the lifetime of most gearbox mechanisms is an increase in vibration loading by 2.5–31.6 times over the acceptable levels. The practical significance of the results obtained is in solving the problem of improving the design and manufacturing of tractor gearboxes T-150k through the use of the developed criteria for permissible vibration by methods of reducing the vibration level of detected defects. All the above mentioned makes it possible to create a complex of normative and technical, and methodological documentation to improve the reliability of tractors.

This article presents theoretical studies of methods for assessing car quality indicators in the operation stage. Important criteria for determining the quality indicators of cars during the operation phase are the following: functional stability, ecology, comfort, technical solutions, and traffic safety. The problem of converting a multicriteria quality assessment to a single criterion is proposed to be solved by the method of determining a quality index. The methodology for the practical and actual implementation of this research is based on the evaluation of the quality index established on the average vehicle speed then the basic methodological principles are formulated. The quality index of a car is significantly dependent on the operating conditions. This article presents the correction coefficients for the quality index of base, hybrid, and electric vehicles, depending on the operating conditions. The studies and the proposed car quality index provide timely information on the characteristics of operating conditions, creating the necessary conditions and opportunities for automakers to improve the design of cars, promote the image of car brands, and increase sales.

The reliability, safety and economy of the electric vehicle depend on the operation of the electric drive. Diagnosing malfunctions at startup avoid an accident by turning off the system power. Idle testing prevents an accident that may occur while driving. Monitoring the technical states of the electric power supply during the transport process provides an emergency operation mode by redistributing power between its elements. This model presents the results of testing the method of spectral analysis of electrical processes occurring in the power circuit of the electric power supply simulation model. The information content of spectrograms, as a characteristic of the diagnostic parameter, is determined by the options for setting up the FFT analyzer. These options are configured to a maximum frequency switching converter. And other is the sampling period of the spectral characteristic, and the fundamental frequency is selected as multiples of the rotation speed of the electric motor and the switching frequency of the inverter, taking into account the number of phases of the machine. This paper deals with faulty states of electric drive. It is associated with the failure of a functional element, the circuit (breakage or closure) or the deviation of the element parameters from the nominal values. In the first case, the structural identification problem, the system's state, is considered the second -parametric.

TiO2-based materials have high strength and suitable electronic properties that make TiO2 widely used. In this research, Co-doped TiO2 thin films were created through the sol-gel spin-coating method. The deposition process was conducted 3 times to prepare 1 to 3 layers. The structural, morphological, and optical properties of Co-TiO2 thin films were explored by XRD, SEM, and UV-VIS analyses. The prepared films were amorphous without a crystalline structure. SEM images demonstrate highly uniform particles on the surfaces. With the rise of thickness, nanoparticles get closer, and the particle size decreases. EDS spectra verify the existence of Ti, O, and Co in all samples. The transparency of thin films was reduced by increasing the thickness. Bandgap energy decreased with increasing the deposition layers, while Urbach energy increased.

This paper reports a study into the historical and economic preconditions for the strategical development of agri-food corporations in the competitive economic space of Ukraine. Agri-food corporations are determined by us as corporations with a developed system of integration relations that are a non-agricultural enterprise, which produces agricultural products. It has been substantiated that their emergence is not a natural phenomenon but a systematic process of changing the phases of differentiation and integration in the national economy. In this case, the development of agri-food corporations was contributed to by the lack of institutions of effective antitrust control, the diversification of industrial and financial groups, the liberalization of foreign trade, as well as a rent-oriented behavior of economic agents. It has been shown that agri-food corporations currently utilize about a third of agricultural land while the size of some of them exceeds the land-use area of entire regions. At the same time, in terms of agricultural production efficiency, agri-food corporations outperform farms and disintegrated agricultural enterprises, as well as family-owned farms; they have more resources for the innovative development of agricultural production and for investment. Strategical development of agri-food corporations needs to develop its social responsibility in rural areas, intensification of public control over the impact on the agrarian sector, institutional system of state support of export. Under the conditions of the state regulation of monopolies and excessive corporatization of agrarian sector, agri-food corporations should constitute the core of food security in Ukraine, as well as form its competitiveness in foreign agricultural markets.