卷 31, 编号 3 (2021)

Introduction. The use of biomass allows increasing the rate of biogas formation and its specific yield. This work aims to study the kinetics of methanogenesis and determine the optimal duration of digestion and organic load, which are the main indicators of the technological process of biogas formation.
Materials and Methods. The substrate (dairy manure, biomass of amaranth) was the study object. Experimental studies were carried out using a laboratory biogas plant. The computer program (certificate No. 2018662045) was used to obtain modified Gompertz models describing the kinetics of biogas formation. Based on the obtained data, the hydraulic retention time and organic loading rate (the key parameters in the design of biogas plants were determined).
Results. The paper presents the experimental studies results of the biogas formation kinetics when using dry amaranth biomass. The Gompertz mathematical models were obtained. Methane-tank control parameters (hydraulic retention time and organic loading rate) were obtained for anaerobic digestion of a new substrate.
Discussion and Conclusion. The use of new co-substrate Amaranthus retroflexus L. allowed increasing the specific biogas yield from dairy manure by 52.2 % and the ultrasonic pre-treatment in combination with the herbal supplement by 89.1 %. The optimal hydraulic retention time value was 10 days and organic loading rate was 4.1 kg of volatile solids per m3 of digester per day.

Introduction. The article describes the approach to solving the problem of complex technical system troubleshooting based on expert knowledge modeling. Intelligent information systems are widely used to solve the problems of diagnostics of multilevel systems including combine harvesters. The formal description of the subject domain knowledge is the framework for building the knowledge base of these systems. The sequence of creating an expert system knowledge base in accordance with production rules is considered.
Materials and Methods. The approach is founded on the fault function table. As the object of diagnostics, one of the subsystems of the combine harvester electric equipment “opening the hopper roof flaps” is considered. The basis for constructing a sequence of elementary checks is a system of logical equations describing both the serviceable and possible faulty states of the subsystem.
Results. A structural logic model is developed. As a result of analyzing the fault function table, the sets of elementary checks are determined. Four criteria have been used to analyze the weight of these checks. The authors have determined optimal sequence of checks and have developed a decision tree, which allows finding the cause of the malfunction and is the basis for creating the knowledge base of an intelligent information system. A fragment of the knowledge base is given.
Discussion and Conclusion. The proposed approach of expert knowledge modelling increases the efficiency of the unit for troubleshooting of the intelligent decision support system. It makes possible to structure the base of expertise and establishing the optimal sequence of elementary checks. This allows determining the optimal sequence of application of the knowledge base production rule that makes it possible to reduce the time of restoring the serviceability of combines.

Introduction. An increase in crop production from the growing area of both vegetable root crops and all agricultural products results in grows of the load on the machine-technology complex when harvesting. The reason is that in the structure of machine-technological complexes there are not devices providing the qualitative screening of the heap incoming for processing. The purpose of the study is to identify the areas with the minimum value of soil screening on the rod elevator surface depending on the elevator apron angle and to develop recommendations and proposals for improving the separation quality.
Materials and Methods. The article describes the methodology and results of laboratory studies of rod elevators with an asymmetric arrangement of web agitators and an adjustable elevator apron angle to determine the soil screening quality on its surface. We used the method of comprehensive assessment of the quality and stability of technological operations based on quantitative optimization criteria.
Results. The highest value of the screened soil weight is at the wavelength attenuation section of the rod elevator working branch 1,020 mm cause by action of the elliptical web
agitator at an elevation angle of 5 gon.
Discussion and Conclusion. The rod elevator with asymmetric arrangement of web agitators and adjustable elevator apron angle increases the soil screening quality along the entire length of the elevator apron by 10 %, and therefore increases the completeness of separation of root crops from soil impurities.

Introduction. In addition to grain, a grain heap of rye may contain poisonous ergot sclerotia. Modern grain cleaning machines do not isolate ergot sclerotia in one technological process because of the similarity of physical properties in linear dimensions. Isolation of ergot sclerotia from rye grain in one technological process is possible through the use of aqueous solutions of inorganic salts. The purpose of the study is to determine the optimum elevation of the loading hopper relative to the liquid surface. The data obtained contribute to increasing the quality of the technological process of the machine being developed.
Materials and Methods. The paper considers the delivery of rye grain flow from the loading hopper outlet into the liquid by varying the specific grain load, liquid density and the delivery height. To set up the experiments, the experiment design methods have been used. The experimental data have been processed using the statistical package Statgraphics Plus 5.1.
Results. The estimation of the effective elevation of the loading hopper outlet relative to the liquid surface when delivering grain flow has been carried out. There have been obtained regression models for the fraction of grains, which did not submerge and rose up to the liquid surface with air bubbles.
Discussion and Conclusion. It has been found that the density of the aqueous salt solution has a significant effect on the percentage of grains, which did not submerge and rose up to the liquid surface with air bubbles. The smallest values of at different density of the liquid and specific grain load are achieved at a grain delivery height 56.0 ∙ 10–3 m.

Introduction. To keep automobiles and tractors in operation conditions, it is necessary to restore the inner cylindrical surfaces of the friction pair parts. This is the most laborintensive activity. The method of electroplated contact deposition of composite coatings, based on elastic plastic deformation of formed layers, is used for repairing surfaces. To use this method it is necessary to determine the values of the elasticity modulus, on which the wear resistance of tribocouplings depends.

Materials and Methods. For the study, cylindrical samples made of 30 HGSA and 30 HGSNA steels were used. Electrolyte containing 200–250 g/l chromium oxide, 2.0–2.5 g/l sulfuric acid, and distilled water was used for electroplating the coatings. When calculating the stress-strain state, the apparatus of continuum mechanics was used.
Results. The dependence of the coating pliability as a function of the parameters of individual elementary layers is determined. When the multilayer coating of three types (orthogonal-reinforced, cross-reinforced and quasi-isotropic) is applied, its structure does not depend on the angles of kinematic tool movement on the inner cylindrical surface of the part. For each type of coatings, the way to determine the constant stiffness coefficients of the layers is specified. The dependences for calculating the elasticity modulus of the applied material are derived from the values of the stiffness coefficients.
Discussion and Conclusion. In determining the modulus of elasticity of multilayered composite coatings, the calculation is made for the individual layers by passing to the convective coordinates, which is in complete agreement with the Lagrange point of view on the study of the motion of a continuous medium. The results obtained are of practical significance in the selection of the coating material to be applied for the restoration of internal cylindrical surfaces.

Introduction. Greenhouse lighting systems are an integral part of the system for growing plants in cultivation facilities with an artificial microclimate. The uniformity of light distribution over the growing area is important to increase energy efficiency and improve plant quality, among other requirements. 
Materials and Methods. The basic concepts of the subject area such as lighting, lighting body, horizontal lighting curve, luminous intensity curve are considered in terms of theoretical photometry. To assess the energy and ecological friendliness of the greenhouse horticulture, the lighting efficiency factor was used. Various methods for determining the average lighting value are presented. The formulas for the uniformity coefficients are presented. Experimental verification was carried out on a horizontal plane simulating a surface for growing plants. A luminary with a round-symmetric light distribution was used.
Results. It has been found that the lighting values calculated by the proposed method at various points of the illuminated surface correspond to the experimentally obtained values. It has been shown that the coefficient taking into account the pattern of lighting distribution over all points of the surface carries a lot of information about the uniformity.The relationship between the lighting efficiency and uniformity of the generated lighting has been revealed. With reduced suspension height of the luminary, it is possible to increase significantly the lighting efficiency factor, however, the lighting uniformity deteriorates sharply.
Discussion and Conclusion. There is proposed a method for assessing the energy efficiency by the lighting efficiency factor, which determines the proportion of the useful lighting falling on the surface in the total lighting generated by light sources. It is suggested that this indicator can characterize the ecological quality of photoculture, since it has been established its relationship with the uniformity of the created lighting, the impact of which on photoculture is described in the literature.