05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
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MODERN TECHNOLOGIES FOR GRAPE STORING
05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
DescriptionThe article gives a review of modern technologies of storage of grapes. The main tool for stabilizing the quality of grapes during transportation and storage is the use of sulfur dioxide (SO2), a gas that has properties that can inhibit non-enzymatic darkening, reduce the activity of enzymes, effectively control the development of Botrytis cinérea (a phytopathogen that causes gray rot) and acts as an antioxidant. Researchers pay particular attention to control the release rate of SO2, as it is important in the first stage storage to ensure supply of significant quantities of SO2 for a short period of time, which eliminates Botrytis spores that are present on the surface of berries and to stabilize the damages formed during transport and filling; the second step is to ensure a steady supply of the minimum quantity of the SO2, to ensure the control of microbiological spoilage. For a long storage time. To preserve the quality indicators of grapes during storage, it is possible to use a modified gas environment created in various ways, including through special types of packaging; forced saturation of the environment with gases such as oxygen, ozone or carbon dioxide. At the same time, to enhance the effect can additionally apply fungicides, antifungal ear Anti-mold®, etc. There are known technologies for complex processing of table grapes to combat post-harvest microbiological spoilage, which provide for the first stage of treatment with ozone or sulfur dioxide followed by spray treatment with Muscodor albus. An alternative to the use of SO2 is the use of essential oils and hypobaric treatment methods that ensure minimal environmental impact. Positive results during storage are provided by the use of medium-range ultraviolet radiation (UV-B) or short-wave radiation (UV-C), which positively affect the transcription of biosynthetic genes, providing an increase in the content of phenolic compounds and antioxidant activity of grapes, without affecting the content of dry soluble substances, the value of total titrated acidity and pH during storage. The analysis of modern technologies is of interest to practitioners and researchers who develop technologies for storing grapes
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05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
DescriptionThe article introduces a study on the creation of a simulated physical and mathematical model of the working process of a strip thrower, throwing soil in a directed flow. The problem solved with the help of this work is aimed at optimizing the cutting and ejection process in a given direction of the soil with minimal energy consumption with a maximum emission range. The article describes a methodology for calculating the milling thrower, which is oriented to the formation of the required amount of soil to create a mineralized strip at the edge of a forest bottom fire. Improving and realizing the full reproduction of physical and mathematical models using process simulations, you can save resources on the development of forestry aggregates. The study presents a productive method of processing soil with milling cutters, which helps to reduce energy consumption due to the formation of oriented mineralized flows of soil. For a physical and mathematical description of the process, a simulation program has been compiled that allows you to test the specific task of minimizing energy consumption at a maximum distance of soil discharge with a constant flow density to the rotational speed of the milling throwers
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PROSPECTS OF APPLICATION OF LASER SURFACING AT RESTORATION OF DETAILS OF AGRICULTURAL MACHINERY
05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
DescriptionThe main component of agricultural production is machinery, which is a complex technical system (harvesters, agricultural machines, tractors, cars, etc.). The practice of operation of technically complex machines shows that, in general, the process of replacing worn parts and working devices of agricultural machinery with new ones prevails, and the number of restored products is small. However, experience shows that the technological process of restoration of machine parts allows you to get high quality surfaces of such parts and reduce the cost of repair. One of effective methods of restoration of surface layers of details is gas-flame spraying with the subsequent laser reflow. The article presents the results of the study of the zone of thermal influence in steels U8A and St3, as well as the influence of laser reflow regimes on its microhardness in these steels. It is established that the higher the laser power and the lower the speed of movement of the optical head, the larger the size of the thermal influence zone. Conversely, the lower the power of the laser and the higher the speed of movement of the head, the smaller the size of the zone of thermal influence. The power of the laser and the speed of movement of the optical head slightly affect the value of microhardness. It was also noted that promising areas in the field of restoration of parts of agricultural machines laser welding are: a scientific rationale for the selection of powders; the study of regularities of changes of the microstructure parts, regularities of formation of layers; development of modes and justification of regimes of welding; and, ultimately, the development process of restoring the specific parts
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THEORETICAL STUDIES OF SEED MOVEMENT IN THE DISTRIBUTION SYSTEM OF A PNEUMATIC GRAIN DRILL
05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
DescriptionPneumatic grain seeders with a central dosing system have high productivity due to the presence of a large centralized hopper, as well as a large width of capture. However, they cannot always ensure an even distribution of seeds between coulters. The article performs an analysis of designs of sowing machines. The influence of the angle of rotation of the air mixture in the tap on the drop in seed speed is studied. We also obtained the equation of seed velocity at turns of pneumatic lines of pneumatic seeders. Branches were analytically studied, the outer walls of which were described by various equations in a rectangular coordinate system. Optimal are bends, the contour of the outer wall of which is outlined by the curves of the power function. Analysis of such curves indicates that the optimal curve that provides the smallest meeting angles is a cubic parabola. Based on the considered analytical materials, we found that when developing a pneumatic scheme for transporting seeds of grain crops to the distributor, it is necessary to avoid using taps with horizontal to vertical and from vertical to horizontal
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05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
DescriptionThe article presents results of theoretical and experimental studies on the justification and experimental confirmation of the influence of hydraulic seeding process modes on the parameters of row seeding technology for seedling crops. It is hypothesized that it is possible to ensure a uniform depth of seeding within 0.5...1.5 mm by feeding seeds into the soil by hydraulic means using a liquid. We have compiled a nomogram of the influence of the height of the initial level of the liquid and its density on the amount of pressure exerted by it on the soil. It was found that the pressure of the polydisperse system on the soil increases with both the density of the liquid and the height of the initial liquid level. Experimental studies have been conducted to study the effect of the pressure exerted by the liquid on the soil and the speed of the drill on the depth of furrow formation and the depth of wetting the soil. The article determines empirical dependences of furrow depth on the pressure exerted on it for different types of soils. It is found that the depth of soil wetting decreases with increasing speed of the drill
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JUSTIFICATION OF THE RIGIDITY OF COMPOSITE BARS OF A POTATO HARVESTER ELEVATOR
05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
DescriptionHigh-strength steels are used to increase the reliability of potato harvesters. With the advent of new materials and new technologies in agricultural engineering, it is possible to significantly reduce the mass of working bodies, to reduce energy costs. The elastic system of the composite elevator bar, unbalanced by the impact of the component of the potato heap, is in oscillatory motion. An increase in the height of the fall, and hence the speed of collision with the bar of the component of the potato heap, determines the amount of deflection of the composite bar. During vibrations, in addition to static deformations, dynamic ones are added, depending on the magnitude of the impact force. It was established that a bar made of composite material should have the following parameters: elastic modulus E = 55000 MPa; the diameter of the composite bar d = 0,012 m
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TO THE QUESTION OF MODELING THE PROCESS OF INTERACTION OF THE ELASTIC WHEEL WITH THE SOIL BASE
05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
DescriptionOne of the most important problems facing agricultural production is to increase traction and energy properties and to decrease the deforming effect of wheel propellers of power tractors on the soil. The solution to this problem requires the widespread introduction of computer-aided design systems, which make it possible to predict the towing, fuel, economic, and agro-technological properties of the tractor unit at the design stage. Traction and energy indicators of wheeled agricultural tractors, the level of impact of wheel propellers on the soil are largely determined by the quality of pneumatic tires. The search for the optimal parameters of pneumatic tires, the compliance of tire characteristics with the parameters and operating conditions of the tractor unit, require solving two main problems. Firstly, the development of analytical dependencies describing the process of interaction of elastic wheels with the soil base, depending on the rolling mode of the wheel. Secondly, bringing to the engineering level the methods of calculation and analysis of the wheel propellers and soil system. The work discusses the issues of physical and mathematical modeling of a pneumatic wheel and soil system. It is noted that among the existing approaches to describing the process of interaction of an elastic wheel with soil, it is most preferable to use rheological models that take into account the simultaneous deformation and subsequent restoration of the soil and tire. However, when it comes to the existing models, the formation of the area of the contact patch is associated with a common normal deflection, which is not confirmed by numerous experimental studies. In the present work, the concept of agrotechnological deflection of a pneumatic tire is introduced. The developed model makes it possible to calculate the rut dept, the tangential and radial deformations of the tire, the longitudinal and normal deformations of the base, and the contact pressure under a known normal load on the wheel, wheel rolling radius and speed. We have also presented analytical and experimental dependences of the contact pressure and the rut depth on the size of the agrotechnical deflection
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05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
DescriptionThe article presents the results of studying the influence of some types of packaging materials used in conjunction with Inter Fresh’s ethylene absorber (sachets) on commercial quality and losses of Alexandria zucchini, Lyubov sweet pepper and tomatoes cv. Inkas during storage. The study was carried out using StePac Xtend bags, creating a modified atmosphere. The objects of research were stored for 14 days at a temperature of 8 – 10 °С and air relative humidity of 90±3 %. One sachet for ethylene absorption was placed in Xtend bags. It was found that when stored under these conditions, the total weight loss is: for tomatoes – 0.3% when using Xtend bags and Inter Fresh ethylene absorbers, 1.8% when using traditional packaging materials; for zucchini – 0.4% when using Xtend bags and Inter Fresh ethylene absorbers, 1.6% when using traditional packaging materials. Losses associated with microbiological damage during storage of zucchini and tomatoes were not observed. During storage of sweet pepper microbiological spoilage took place, which, apparently, was the result of increased contamination with pathogenic microorganisms
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EXPERIENCE IN IMPLEMENTING EQUIPMENT FOR TOBACCO GREEN LEAF PROCESSING
05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
DescriptionEfficiency of tobacco green leaf processing can be increased by utilizing innovative equipment and technology improving. As a part of research and postgraduate work technology and equipment for tobacco green leaf processing were elaborated. Elaborated equipment consists of set of devices for preparing tobacco leaves for drying, drying and packaging of dry tobacco. Basic element of the equipment is double-sided needle, designed for threading the tobacco leaves and their further curing directly on the needle. The set of devices is patented and has passed experimental testing. This equipment is implemented in scientific and economic activity of the institute. Testing the equipment for large quantities of tobacco has proved the efficiency of new technology for preparing and curing the tobacco leaves and confirmed the validity of technical solutions and characteristics of manufactured equipment. It is determined that 50 devices for double-sided needle arrangement are sufficient per 1 ha of tobacco field. Leaf mass per one double-sided needle can reach 3 – 4.5 kg, depending on weather conditions. Carried experiments have proved the necessity of cutting the upper part of the petioles when placing long stemmed tobacco sorts and periodic distribution of leaves on the needle during the curing. Performing these operations led to obtaining the cured tobacco of high quality. Results of the semi-industrial experiments have proved the efficiency of elaborated technology. Utilizing of innovative equipment is recommended for industrial production of dried tobacco
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05.20.01 Technologies and means of mechanization of agriculture (technical sciences)
DescriptionAn effective factor in increasing the yield of grain crops has long been considered to provide the sown seeds with the necessary nutrition area when sowing. ideally, the plant's nutrition area should be in the form of a circle with an area of 10 ...25 cm2 without overlapping with the neighboring ones. This distribution of feeding areas means an ideal spread of crops without borders and row spacing. However, in the grain production, the standard crop with a row spacing of 15 cm was spread out, where the seed distribution is artificially limited to a narrow strip where the grain feeding areas overlap. According to experts, this placement of seeds, which has developed historically, is not justified by either the experience of agricultural production or agricultural science. The availability of seeds with the necessary feeding area for row sowing is small – about 15%. At the present time, agricultural science is showing increasing interest in the technologies of ideal spread seeding. But the ideal is not yet obtained due to the lack of appropriate coulters. In these conditions, the band seeding method that closely implements the ideal multiple seeding comes to the fore. We propose a number of designs for single-disc and single-disc coulters for strip sowing, which form a fairly wide furrow up to 100 mm