Main Properties Of Operators Research Articles

The state of the Russian agricultural machinery market under sanction pressure conditions

The article is devoted to assessing the development of the Russian market of agricultural machinery (AHT) over the past 10 years. An analysis of the production of the main types of agricultural products, market dynamics, changes in market structure, volumes of purchases by agricultural producers, and the presence of agricultural products in Russian agriculture are presented. For a comparative analysis of the agricultural tractors being sold, their main technical and economic indicators are presented. Calculations were made of the main operational properties (performance, fuel consumption) of tractors of similar traction classes of the Belarus family and Chinese-made tractors presented on the Russian market. Based on correlation analysis, the relationship and direction of indicators were verified: renewal rates, retirement rates and the availability of a fleet of agricultural machinery; acquisition of agricultural equipment and renewal and disposal rates; acquisition of agricultural equipment and availability of agricultural machinery in agricultural organizations. Quite a strong relationship between the indicators: “purchase of agricultural products” and “availability in agricultural organizations” (correlation coefficient r = 0.676 — 0.99), a significant relationship between the indicators: “retirement rate” and “availability of combine harvesters” (correlation coefficient r = from — 0.588 to -0.664), “purchase of tractors” and “disposal coefficient” — r = –0.445, there is practically no relationship between the indicators: “purchase of tractors” and “availability of tractors” — r = –0.06, “renewal coefficient” and “availability grain harvesters” — r = -0.183, “purchase of forage harvesters” and “disposal rate” — r = –0.187. When analyzing the performance properties determined in this study, it was revealed that Chinese tractors presented on the agricultural machinery market will provide significant competition to tractors of the Belarus family.

Технологическое обеспечение эксплуатационных свойств сопрягаемых поверхностей элементов сборной формообразующей оснастки с учетом установленной долговечности пресс-форм

Design and technological concepts are viewed at the stages of designing, manufacturing and joining process providing for the required reliability (durability) of mold elements. Recommendations are given for rationing and achieving the parameters of accuracy and quality of mating surfaces, taking into account the formation of the necessary operational properties at the main stages of the product life cycle. The factors that have the greatest impact on ensuring the correct and accurate location of forming tool elements have been elicited. The concept of determining the actual contact area and calculating the scale parameter, which provides a contact interface degree specification for conjugated surfaces, is presented. The hypothesis of the formation of reliability indicators is found, taking into account the manufacturing capability and technical capacity of production with the introduction of correction of the upper and lower dimensional deviations included in the dimension chains and ensuring the pre-set accuracy parameters of the master link. The analysis of the operating conditions of the studied type of pressmold elements is carried out. The main operational properties that provide the required operating time for shaping part failures are identified and analyzed. Special attention is paid to the study of the structural features of such parts, a comparison of the integral and prefabricated structures is made, and also, contact stresses under the joining operation for the most promising of the latter are calculated for contact interface degree simulation. This will allow developing practical recommendations for any type of compound forming tool for the benefit of basic mechanical properties rate making, accuracy indicators, including deviation allowances in the correct geometric shape, including quality parameters of the surface layer at the designing stage,processing methods dispatch and modes setting at the manufacturing and testing stages and also suggesting the amount of static loading when assembling.

The effect of phosphorus content in copper alloys used for crystallisers of continuous casting machines

One of the key elements defining the technical level and operational capabilities of continuous casting machines (CCM) is the complex of physico-mechanical properties of copper or copper alloys used in its production. The paper provides a comprehensive assessment of the possibility of obtaining high-quality copper plates for CCBC crystallizers based on domestic technologies and equipment using refined copper. Special attention was paid to the need to optimize the chemical composition of the copper alloy within a narrower range of chemical element values. The analysis of the research shows that currently used copper alloys for CCM crystallizer manufacturing have a wide range of fluctuations in the main operational properties, namely thermal conductivity (260-390 W/(m·K)) and solidification temperature (250-700 °C). However, most of the alloys used have narrower fluctuation limits for acceptable values, constituting 340-390 W/(m·K) for thermal conductivity and 300-370 °C for solidification temperature, significantly depending on the impurity content in the copper alloy. Generalizing graphical dependencies, it should be assumed that the rational phosphorus content in the alloy is in the range of 40-120 ppm. In this case, the thermal conductivity of the alloy will be in the range of 370-400 W/(m·K), the solidification temperature will be 410-440 °C, and the recrystallization start temperature will be 370-400 °C. Moreover, such a phosphorus content interval is technologically feasible to maintain during billet casting. It is also shown that normalization annealing after cold deformation in the temperature range of 320-350 °C is capable of increasing the thermal conductivity of the alloy by 1-2 %. As a result of the conducted research, optimal limits of phosphorus content in fire-refined copper were established, ensuring the level of its physico-mechanical properties not lower than the indicators characteristic of alloys obtained from cathode copper. However, besides phosphorus, other alloy impurities, the content of which differs from the values characteristic of alloys obtained from cathode copper, may affect the properties of the material made from refined copper. Therefore, further research will focus on studying their complex impact on the physico-mechanical properties of refined alloys.

Dependence of Tractor Traction Properties on Agricultural Machinery Connections

Tractor traction properties depend on many factors including engine power, operating weight and tractor weight distribution across axles, dimensions, profile, gears range and gear count in the gearbox. Moreover, the tractor technical condition plays a vital role, encompassing aspects from the fuel system affecting the engine power output, to the chassis, influencing terrain traversability, maneuverability, and soil deformation. (Research purpose) The paper addresses several research problems. To investigate the impact of the agricultural machinery connections with the tractor on the tractor traction properties, and determine the impact of agricultural machinery weight, and grip width on the main technical and economic parameters. To analyze how geometrical parameters of tractors and agricultural machinery correlate with soil reactions under the machine support wheels as well as the front and rear wheels of the tractor. To determine the influence of the design characteristics of cultivators with varying working widths on the main operational properties of the machine-tractor unit. (Materials and methods) The study involves examining the operation of the Belarus 82.1 tractor with cultivators KPS-4 and KPS-5 from different manufacturers. Various methods were employed, including calculation, calculation-construction, calculation-graphic analysis, economic-mathematical techniques, along with comparison, measurement, and description. (Results and discussion) This study identified indicators impacting the load redistribution transmitted to the tractor from mounted cultivators. Based on these indicators, alterations in soil reactions under cultivator support wheels and the tractor’s rear wheels were deduced. (Conclusions) The calculations on the effect of mounted cultivators with different working widths (different operating weight) on the redistribution of soil reactions between axles, enabled the determination of modifications in tractor traction force, machine-tractor unit productivity, and specific fuel consumption.

Phosphorus-containing flame retardants for fire-safe foamed polymers

The increased fire hazard of foamed polymers hinders their widespread use in the construction industry. An effective method of reducing the combustibility of carbonizing polymers is the use of phosphorus-containing flame retardants. Therefore, investigation of the influence of phosphorus-containing flame retardants to the composition of pyrolysis products and operational properties – heat resistance, flammability, combustibility and smoke generating ability – is the important objective. In the article we have presented the results of related experimental studies. The effects of phosphorus-containing flame retardants on heat resistance and main operational properties related to fire-safety of foamed constructional polymers are examined. A correlation was found between the results of evaluating the combustibility of foams by the limiting oxygen index and the combustibility index. Optimal concentrations of phosphorus in the foamed thermosetting polymers are established. It was shown that optimal concentration of the flame retardants leads to low combustibility of polyurethane-, resole- and urea-based foamed polymers.

Reduction of waste disposed to the environment through recycling of unused methyldiethanolamine

A 30% aqueous solution of waste methyldiethanolamine (MDEA) can be regenerated, reused in gas treatment, and its residue can be used as a secondary raw material in another area of production. (HOCH2CH2)2NСH3 is separated from water by a 30% aqueous vacuum-extraction method. MDEA and its destroyed part remain in the column. In laboratory conditions, it was shown that the degree of purification from destruction products by this method is from 60 to 78%. The analysis of the research results showed that the parameters of the main operational properties (density, viscosity, surface tension, foaming) of purified amine were significantly improved.

Possibilities of measuring roughness with the probe contact method and promising methods for improving the process

One of the main operational properties of the product is the surface roughness. The presence of micro-dimensions and their size affect the strength, chemical resistance, abrasion and even the appearance of the product. But any real surface after metalworking acquires depressions and protrusions that are absent on a perfectly smooth surface. Therefore, the determination of surface roughness is one of the key parameters for metal products.Processes occur on the surfaces of parts that have a negative impact on them: the emergence of cracks, wear due to friction, erosion and corrosion damage, crumpling. Often such defects in materials have no less impact than deformation. The addition of certain microgeometric properties to the surface increases the resistance of the part to external influences and, as a result, increases strength and reliability. Therefore, the surface roughness parameters are of extremely important technical importance. In the course of research, the question of the variability of roughness on the surface of plexiglass from the effects of sandpaper of different grain sizes was investigated. The problem of scratches of plastic elements is very acute, especially when it comes to protecting the exterior of parts made of plexiglass and plastic. That is why a study was conducted showing the dependence of roughness on the sample of abrasive material

Theoretical study of the accumulation of mechanical mixtures in the engine lubrication system

The work in the field of oil obsolescence, theoretical identification of active additives contained in the oil as a benchmark for evaluating the main operational properties of oil, as well as a theoretical assessment of the properties of oil oxidation resistance and the resource of its active elements, depending on the intensity of the eating of engine details and the amount of elements. The sharply changing climate and high pollination conditions of the republic, a sharp increase in the amount of water and mechanical mixtures, which in turn can lead to a premature departure of motor oils used in it, such as viscosity, corrosion resistance, oxidation resistance, washing and other properties, and acceleration of engine eating. Due to the overload of the tractor, theoretically determined that mechanical mixtures and asphalt products containing oxidation products containing motor oil in the engine maintenance system increased by 1.2%.

Оцінка довговічності металоконструкцій автотранспортних засобів

The article deals with the development of algorithms preliminary assessment of the main operational properties wheeled vehicles - safety bearing the example of trailers at the design stage to improve the level of This work involves analytical studies of the performance of vehicles in order to increase their reliability and durability. The reliability of wheeled vehicles directly depends on the reliability of their individual components. The reliability of one of its main components of the supporting frame plays an important role in the reliability of trailer vehicles. Usually the least reliable elements of the frame of the supporting frame are welded joints. During operation, the load-bearing system of the trailer perceives the spatial load acting on it during operation, and their direction and magnitude of effort are random. Existing load-bearing frame theories describe load systems for frame metal structures with symmetrical and inclined, vertical and horizontal forces that occur when moving at speeds close to the maximum. In analytical calculation, the issue of accuracy and correctness of the calculation of the metal structure of the load-bearing frame is relevant in terms of ensuring the maximum reliability and quantitative assessment of the total stress. Solving this problem at the stage of design development and design has a positive effect on the accuracy of calculations, which in turn leads to a significant increase in strength and projected service life of the structure. In order to reduce the time spent on calculations and experimental evaluation, reference books are used, which contain the calculated strength indicators of structural and technological variants of nodes, which have more rational indicators compared to the basic variants. The algorithm of preliminary estimation of the basic operational characteristics of wheeled vehicles, increase of their productivity and reliability at the design stage is offered in the work. An example of the application of this algorithm to lifting trailers is the load analysis system on the frame of the universal trailer "Kröger GmbH THL 20".

PERFORMANCE CHARACTERISTICS OF SLAG-ALKALI DECORATIVE CEMENTS AND MORTAR

The use of slag-alkaline cements as decorative cements is quite promising. When using bleaching additives TiO2, kaolin and CaCO3, white cements with a degree of whiteness of 70...94%were obtained. But in addition to decorative properties, such cements and materials based on them are subject to requirements to ensure the necessary technological and operational properties.The article discusses the main operational properties of decorative slag-alkaline concrete mortars - long-term strength, water-holding capa-city of mixtures, resistance to fflorescence, resistance to steaming and exposure to atmospheric factors(frost resistance, weather resistance, color stability).It has been established that white slag-alkali cements at the age of 28 days have a compressive strength of 49...56,8 MPa. All compositions of white cements have good hardening dynamics and, based on the strength at the age of 2 days 35...37 MPa, they can be classified as fast hardening. It hasbeen established that in the long term (3 months ormore) the strength of slag-alkaline decorative cements practically does not differ from the control compositions and amounts to 66,5...67,5 MPa.All compositions of slag-alkaline decorative solutions demonstrate high frost resistance. It has been established that the loss of their strength after 150 cycles of freezing and thawing (which corresponds to the F200 brand) is only 1,73...3,87%, there are no weight losses, no surface peeling is observed. All samples of slag-alkaline decorative mortars containing bleaching additives successfully passed the weather resistance test. Their strength loss after 100 cycles of soaking and drying amounted to 6,5...9,2% with an allowable 25%.The high color fastness of slag-alkali decorative pigmented cements to the effects of ultraviolet radiation and steaming has been established. Color as a result of exposure to ultraviolet irradiation and thermal treatment has not changed. In addition to industrial mineral pigments, red mud, which is awaste product of alumina production, has been successfully used as a pigment.In the course of the work, the tendency of decorative slag-alkaline solutions to efflorescence was studied. The introduction of 0,25...0,5% sodium carboxymethylcellulose additive completely eliminates their appearance, improves the water-retaining capacity of solutions and their plasticity.

Обеспечение пожарной безопасности упаковок и тары из древесины

The possibility of developing a methodology for conducting tests to assess flame retardness of packages for storing hazardous substances, materials, or products, as well as the use of the efficient integrated means of modifying wood for their manufacture is considered. The analysis of the basic principles of the methodology of testing the building structures and products of the current standards showed the fundamental possibility of assessing the level of protection of explosive substances, materials or products contained in the package from the effects of fire hazards in the time from the beginning of tests under standard temperature conditions to the occurrence of the standardized limit states. To carry out studies on the assessment of flame retardness of the wooden packages, the means were selected that ensure not only their fire protection, but also weather resistance and moisture resistance, as well as strength. Comparative experimental studies of flame retardness allowed to assess behavior of the wooden packages during complex processing, and to show the advantages of their use to ensure integrity, thermal insulation capacity and the possibility of long-term storage while maintaining the main operational properties. As a result, the principal possibility of using standard equipment and measuring instruments in accordance with GOST 30247.0—94 was established, the main criteria for the assessment of flame retardness were developed, the efficiency of fire protection, as well as the strength characteristics of a complex tool for its possible use in the manufacture of structural elements and wood products, were studied.

НОВАЦИИ В КОМПОНОВКЕ И ПОВЫШЕНИИ ПОПЕРЕЧНОЙ УСТОЙЧИВОСТИ КАРЬЕРНЫХ САМОСВАЛОВ СВЕРХ ОСОБО БОЛЬШОЙ ГРУЗОПОДЪЕМНОСТИ

Main feature of modern mining dump trucks is the need to ensure the transportation of minerals with minimal costs, which is achieved by deepening the quarries (in order to save overburden), increasing the slopes of roads, reducing the distance of cargo transportation, increasing the load capacity of machines and improving the safety of their movement. It is shown that new work conditions of dump trucks and major specific requirements are resolved mainly at the stage of layout of machines by optimizing wheel arrangement of dump trucks, loading of tires and their performance, providing specific power of the propulsion system, choice of the transmission type and its units, and major systems to ensure operational safety: brakes, steering, stability of motion. Special attention is paid to the creation of a new system for improving lateral stability and its design for dump trucks with a load capacity of more than 400 t. The results of operational studies of the main layout and design solutions adopted for a dump truck with a load capacity of 450 t are presented. Efficiency of the decisions made is shown which made it possible to create a mining dump truck superior to all analogues in the world by indicators of the main operational properties that ensure competitiveness: fuel efficiency, performance, and operating costs. A system created for the first time for increasing lateral stability (schematic diagram and structural elements) confirmed the projected traffic safety in typical quarries and the necessary life in operation.

Development of a methodology for evaluating the operational properties of elastic elements for various purposes by acoustic emission

In transport engineering, elastic elements are widely used that work under static, dynamic and cyclic loads. Elastic elements are required to demonstrate specified operational properties within specified limits and for a long time. The most widely used mechanisms are tension, compression and torsion springs with a different profile and made from various materials. The main operational properties of elastic elements are strength, relaxation resistance and elastic characteristics. The existing methodology for assessing the relaxation resistance of elastic elements consists of building a relaxation curve using the results of measurements of the force before and after cyclic loads. This technique has the following disadvantages: the relaxation resistance of a sample batch of elastic elements is assessed; and the control implementation is associated with a significant complexity and high energy costs. To assess the most important indicators of reliability and durability, as well as relaxation resistance for a long period of operation, non-destructive testing methods, including the acoustic emission method, are of interest. Existing techniques are highly complex and do not always guarantee a good result. We propose to use a technique based on the registration of acoustic emission signals.

INDIRECT CONTROL GYROCOMPASS FOR LAND MOBILE VEHICLES

This work consists of two parts. The first part is a historical overview of the creation of two generations of marine and land gyrocompasses with direct and indirect control. During the review of pendulum or direct control gyrocompasses, using primary sources and authoritative secondary sources, the main practical and analytical developments that led to the creation of the first industrially applicable marine gyrocompass are highlighted. The review of non pendulum or indirect control gyrocompasses is largely an original study of the origins of their creation that is provided through an analysis of available patents taking into account the lack of other available early sources. There are distinguished the developments according to the patent of Narciss Ach (1906, Germany) where the scheme of the gyrocompass with indirect control probably appeared for the first time, the developments according to the patent of Preston R. Basset (1923, USA), where the scheme of proper tuning of indirect control gyrocompass appeared for the first time, and other developments as well. There are also considered the developments of a gyrocompass with electromagnetic correction by Pavel Koptyaev (1932, 1951-1954, USSR) and the main industrial developments of corrected gyrocompasses in the territory of the former USSR. The review also briefly indicates the main operational properties of marine and land gyrocompasses, including a new generation of gyrocompasses based on fiber-optic gyroscopes (FOG) and hemispherical resonator gyroscopes (HRG), attitude heading reference system (AHRS). The second part of this work reasonably follows from the first part, in which the gyrocompass with indirect control for land mobile vehicles based on a dynamically tuned gyroscope (DTG) on a platform stabilized in the horizon plane is studied. A general model of errors of such gyrocompass is determined, when the main axis of the gyroscope is brought into the plane of the true (geographical) meridian in the direction to the North and in the direction to the South. A hardware compensation scheme for the systematic errors of the gyrocompass is provided. A problem of determining and compensating for the gyroscope own drift relative to the horizontal axis of the suspension is solved through indirect measurements. The estimation of parameters of the indirect control gyrocompass is provided as a device of a navigation accuracy class

The impact of the quality of diesel fuel on the efficiency of engines

High-quality diesel fuel is the guarantee of work of an internal combustion engine. Low ambient temperature has an influence on the physical and chemical properties of diesel fuel. It becomes a reason for failure of details of a high pressure fuel pump system. This issue is more acute in the Republic of Sakha (Yakutia) where the surrounding air temperature can reach up to -60C and where the essential goods are delivered to the regions of the Far North by winter roads. The article illustrates the results of experimental study of the quality of arctic diesel fuel taken from different filling stations of the Republic of Sakha (Yakutia). It also suggests a way of increase of fuel efficiency for equipment operated in the North. The article also presents a mathematical model of fuel cost during winter time. The main operational properties of arctic diesel fuel are studied. The work was carried out in the laboratory of “General, analytical and physical chemistry” department. The samples of diesel fuel were divided into three categories according to their geographic locations: central, northern and riverside. Three samples of arctic diesel fuel from different filling stations were taken in each of the regions. The study revealed that the chosen main properties of diesel fuel, such as: density, viscosity, fractional structure and low-temperature properties differ from standard values.

Emerging Memristor-Based Logic Circuit Design Approaches: A Review

This article is a comprehensive review of the state-of-theart of memristor-based logic circuit design concepts of the recent literature. Amongst all the identified circuit design approaches, those discussed here are all based on collective memristive dynamics and share a number of common characteristics which facilitate their comparison. The focus is on the evolution of the memristor-based logic circuit design strategies from the early proposed sequential stateful logic up to most recently published design schemes which support parallel processing of the applied input signals. The main operational properties of all the selected computational concepts are presented in an accessible manner, aiming to serve as an informative cornerstone for students and scientists who wish to get involved in emerging memristive logic circuit research and development.

On value operators in differential games

In the paper basics of programmed iteration method is studied. This method appeared for the purposes of research of non-regular differential games. We consider zero-sum differential games with terminal payoff. We introduce value operators and prove main properties of operators used in programmed iteration method. Mathematics Subject Classification: 49N70, 49L25

Organosilicon sealants with enhanced fungus resistance

The results of investigations on the fungus resistance of organosilicon sealants, specifically Viksint U-4-21 and Viksint U-2-28, are presented. It is shown that the introduction of 0.1 wt % of the antiseptic additive thiuram into the sealant formulation does not affect their main operational properties and enhances fungus resistance of the sealants up to 1 point.