Multifactor Experiment Research Articles

Improving the efficiency of organizing technical service of equipment for processing oilseeds

In the article presented to your attention, in order to reveal the effectiveness of technical service of equipment for processing oilseeds, the modes of its functioning have been investigated. A multifactor experiment was carried out to determine the minimum costs for organizing the technical service of oil-extracting equipment. The optimal values of the response function Wopt are found, that is, the minimum costs for organizing the technical service of oil-extracting equipment. The response surface has a clear optimum for the following values of the factors: {1.32; 3; 1,022}, the regression equation is obtained. Optimization of the technical service of equipment for processing oilseeds according to this equation makes it possible to increase the coefficient of technical utilization from the existing 0.86 to 0.93, which increases shift productivity and annual production of vegetable oil by 7.0% with a slight increase in total labor costs by 6.69 % due to the increase in the number of repair and technical workers and the strengthening of the service of the chief engineer of the enterprise.

ЗАСТОСУВАННЯ МЕТОДУ БАКТЕРІАЛЬНОЇ ОПТИМІЗАЦІЇ ДЛЯ МІНІМІЗАЦІЇ ВИТРАТ ЧАСУ ПРИ ПРОВЕДЕННІ БАГАТОФАКТОРНОГО ЕКСПЕРИМЕНТУ

Experiment planning allows you to get a mathematical model in a time and resource restricted conditions. When conducting experimental research in industry, methods of optimizing production processes are used. The order of the levels’ alternation of production processes’ change has a strong influence on the time of the experiment. Most often, experiments are multifactorial and associated with the search for optimal conditions for the experiment, the selection of the most rational equipment. At the same time, there is an urgent need to improve the efficiency of experimental research. There are many factors to consider when implementing a project. The main tasks are to use the initial data, carefully study them with a minimum amount of observations and information, study the 31 influence of individual factors and calculate the most effective procedure for performing the experiment. One of the main tasks is to obtain the maximum amount of information that is useful to us, so that when we re-examine, we can take into account the previous results and use this data to increase efficiency and reduce the time spent in subsequent experiments. One of the advantages is the versatility of the method and the possibility of applying it in a large number of research areas. The purpose of this article is to further develop the methodology of time-optimal experiment planning. Therefore, there is a need to increase the level of research efficiency with a minimum investment of time and resources. From the reasons listed above, we see that there is an urgency to automate and optimize experiments. Based on this, a bacterial optimization method was developed for matrix optimization. The analysis of known methods of synthesis of time-optimal experimental plans was carried out. The effectiveness of the bacterial method is shown in comparison with the original experimental outline, analysis of permutations and random search. Object of research: planning processes of multifactor experiments in conditions of limited time and resources. Subject of research: application of the bacterial optimization method to build a mathematical model with the optimal order of the experiment.

Synthesis and experimental studies of the method of manufacturing screw spirals with a rotating plug with feasibility study

The structural synthesis of methods of winding screw spirals using the method of hierarchical grouping by means of morphological analysis is carried out and a number of alternatives that allowed to create the improved way of winding screw spirals with rotating plug is obtained. On the basis of the conducted multifactor experiment the study of torque of the process of screw workpiece calibration per step was performed and the regression dependence was obtained to determine the influence of winding width, wedge angle and winding thickness on the torque of the calibration process. It is established that calibration process of the turn of screw workpiece per step depends on the width, thickness of the spiral and the angle of the wedge of the device. With increasing inclination of the wedge of the device and the thickness of the winding, for the material steel 08kp, the torque increases and reaches 79 N m. It is established that the dominant factor influencing the value of torque is the angle of the wedge of the device, and the least influential is the winding width. The technical and economic estimation of the method of winding screw spirals with rotating plug is carried out and found that the annual economic effect, when replacing the basic version of winding screw spirals (winding on the frame) on the design (winding with rotating plug), when operating equipment in one shift is 16995.79 UAH.

Change in the soils’ fertility level of tea agrocenoses in the transition to cultivation without mineral fertilizers in the humid-subtropical zone of Russia

Research was carried out on the basis of preserved field multifactor experiment on tea crop (Camellia sinensis (L.) Kuntze) in the conditions of the Sochi Black Sea coast. The application of NPK fertilizers in different doses and combinations according to the experimental scheme was carried out annually from 1986 to 2011. Since 2012, the use of fertilizers has been completely discontinued. The fertility indicators of long-fertilized brown forest acidic soils (in layers 0-20/20-40 cm) were compared with those after 7-8 years of fertilizer withdrawal. During the period of fertilizers’ application, the level of soils’ nitrogen supply significantly exceeded the control (by 30-75/30-56 mg/kg depending on the doses of nitrogen fertilizers). After the fertilizers’ discontinuity, nitrogen supply level equalization occurred in all experimental options. The content of labile phosphorus in soils previously fertilized with high phosphorus doses (120 kg P2O5 ha-1 year-1 and more), during the period of experiment’s conservation decreased by 450-500/350-450 mg/kg, but exceeded the control in 2-2.5 times; in soils previously fertilized by low doses, the indicators have not changed significantly. In soils highly supplied with labile potassium, the content of the element decreased by 70-140 mg/kg. The yield of tea in 2019-2020 was equally low (12-26 cwt/ha) on all options, 2.2-3 times lower than fertilized plantations. After the fertilizers’ withdrawal, there was a decrease in acidity (an average increase in pH by 0.18-0.24/0.12-0.20 units) of agrogenic-acidized soils and an increase in their oppressed respiratory activity (on average by 1.6 times). These changes reflect the tendency of soil self-restoration after the removal of the fertilizers’ load.

Energy and material saving technologies for construction of main pipelines for oil and gas transportation

Based on the study and analysis of technologies and technical means for transporting oil and gas through main pipelines, energy and material-saving methods of their construction are scientifically substantiated. A method for designing trunk oil and gas pipelines with variable wall thickness is proposed, which is possible under the conditions of the current interstate standard GOST 31447-2012. The technique is based on the use of methods of mathematical and statistical modeling and construction of a multifactor experiment and processing of experimental data. Based on the results of the construction of the model, the optimal parameters for the construction of pipelines were found, new technical solutions were proposed that would significantly reduce the energy and material consumption of laying pipes during one run, i.e. between transfer pumping stations.

ЗАСТОСУВАННЯ МЕТОДУ ГРАВІТАЦІЙНОГО ПОШУКУ ДЛЯ МІНІМІЗАЦІЇ ВАРТОСТІ ПРОВЕДЕННЯ БАГАТОФАКТОРНОГО ЕКСПЕРИМЕНТУ

Experimental research methods are increasingly used in industry in the optimization of production processes. Experiments, as a rule, are multifactorial and are connected with optimization of quality of materials, search of optimum conditions of carrying out technological processes, development of the most rational designs of the equipment, etc. The use of experimental planning makes the behavior of the experimenter purposeful and organized, significantly increases productivity and reliability of the results. An important advantage is its versatility, suitability in the vast majority of research areas. When implementing an industrial experiment, the main task is to obtain the maximum amount of useful information about the influence of individual factors of the production process, provided that the minimum number of expensive observations in the shortest period of time. Therefore, it is important to increase the efficiency of experimental research with minimal time and cost. For this purpose, it is expedient to develop systems of automation of experiments which will allow to reduce terms of carrying out experimental researches and to reduce expenses for them. Object of research: processes of optimization of plans of multifactor experiment on cost and time expenses. Subject of research: an optimization method developed on the basis of the gravitational search algorithm, which consists in comparing the force of gravity (cost) of the first row of the planning matrix of the experiment to the next rows of the matrix. In the study of photoelectric transducers of angular displacements, the efficiency and effectiveness of the gravitational search method were analyzed in comparison with previously developed methods: analysis of line permutations, particle swarm, taboo search. The cost of carrying out the experiment plan and the efficiency for solving optimization problems in comparison with the original plan and the implementation of the above methods are shown.

ОБОСНОВАНИЕ ОСНОВНЫХ КОНСТРУКТИВНО-ТЕХНОЛОГИЧЕСКИХ ПАРАМЕТРОВ ПНЕВМОСЕПАРИРУЮЩЕГО УСТРОЙСТВА КЛЕВЕРОТЁРКИ-СКАРИФИКАТОРА

The most labor-intensive stages of the post-harvest processing of grass seeds are their extracting and cleaning from impurities. For extracting seeds from the hull of clover and other leguminous and cereal grasses, as well as scarifi cation of solid seeds of leguminous grasses, the clover thresher and scarifi er KS-0.2 has been developed. It lacks a device for cleaning the extracted seeds from impurities, which makes it diffi cult to further clean them at subsequent stages of the processing line. To eliminate this disadvantage, a pneumatic separating device was fi tted for cleaning seeds from light impurities. The research aimed at experimental substantiation of the basic constructive and technological parameters of the pneumatic separating device of the clover thresher and scarifi er, ensuring cleaning from light impurities of more than 60%. The study was carried out according to conventional techniques using methods of planning a multi-factor experiment on a laboratory installation of a clover thresher when cleaning red clover seeds from light impurities. The study results have shown that the maximum eff ect of cleaning from light impurities reaches 96.7% with a minimum feed of source material of 200 kg/h, the angle of the grain board inclination of 42.85° and a maximum depth of the aspirating channel of 0.11 m. Based on design considerations and the maximum throughput of the clover thresher and scarifi er, the following combination of factors was chosen as the optimal one: a feed of the source material of 300 kg/h, an inclination angle of the grain board of 45° and a depth of the aspirating channel of 0.09 m. With this combination of factors, the eff ect of cleaning from light impurities meets the technical requirements and equals 75.2%. Thus, the study has determined the basic design and technological parameters of the pneumatic separating device of the clover thresher and scarifier.

Using Grass Germination to Measure the Toxicity of Household Substances & Teach Statistical Methods

We describe a series of three experiments in which students develop a model system for measuring the LC50 of household substances, using grass seed as the model organism. Students use statistical methods to compare two samples (using chi-square and Student’s t-tests), conduct a two-level multifactor experiment to look at multiple factors simultaneously and observe interactions, and make serial dilutions to measure the LC50 over a threefold concentration range. The experimental series was very inexpensive to run and tended to provide very successful LC50 measurements.

PREPARATION OF WOOD FIBER SEMI-FINISHED PRODUCTS IN KNIFE MACHINES OF VARIOUS MODIFICA-TION

In this paper, we consider the results of a study of the influence of the design and technological parameters of grinding machines of various modifications on the quality of wood pulp.
 According to the results of processing multifactor experiments implemented according to the second-order B-plan, a mathematical description was obtained of the dependence of the degree of grinding of pulp on the gap between the grinding disks, wear of the segments, the rotational speed of the lower screw and the concentration of pulp. The obtained regression models are adequate to the process and can be applied in practice for predicting the qualitative characteristics of wood pulp depending on the parameters of the grinding process.
 Analyzing the obtained experimental data, it can be noted that such factors as the state of the surfaces of grinding disks, the gap between them and the concentration of wood fiber have the greatest influence on the degree of grinding of the mass. Evaluation of graphical dependencies allows you to determine the extent to which you can vary the operating and design parameters of the grinding process to obtain wood fiber with the required grinding quality.

DEPENDENCE OF STRENGTH OF FIBERBOARDS FROM TERMS OF PREPARATION OF WOOD FIBER SEMI-FINISHED PRODUCTS

Despite the reduced demand for fiber boards, research related to their manufacture is relevant, since the production of wood-based materials significantly contributes to solving the problem of the integrated use of wood raw materials.
 The paper presents the results of experimental studies reflecting the dependence of the strength characteristics of dry and wet wood fiber boards on the structural and technological parameters of grinding plants of various modifications. The experiments were carried out in laboratory facilities and in the production environment on existing industrial equipment. Based on the results of processing multifactor experiments implemented in a second-order B plan, a mathematical description was obtained of the dependence of the tensile strength during static bending of solid wood fiber boards of the dry and wet production method on the gap between the grinding disks, wear of the segments and the concentration of wood fiber mass. The obtained regression models are adequate to the process and can be applied in practice to predict the strength characteristics of fiberboards depending on the parameters of the grinding process.
 As a result of the analysis of the calculated and graphical dependences obtained on the basis of studies in the production environment on the existing equipment, it is possible to determine what parameters on the grinding equipment must be set in order to obtain the necessary physical and mechanical properties of the fiberboard.

Mathematical planning of a multi-factor experiment and optimization of the feed extrusion process

To increase the level of protein and fat in milk, it is necessary to increase the total amount of feed fed, the diet must be balanced in energy, protein, fiber, minerals and vitamins; the feed must be of high quality. Oilseed waste produced during post-harvest processing and industrial processing contains a sufficient amount of protein and raw fat that can be used in animal feeding diets to increase milk productivity, and when using advanced processing methods, such as extrusion, it becomes a source of environmentally friendly vegetable protein that can increase the nutritional value of the feed several times. In order to study the efficiency of the technological process, the dependencies of quality parameters were determined. Using mathematical methods of planning a multi-factor experiment, a mathematical model of the extrusion process of feed raw materials was developed. The obtained model is used to identify recommended modes of extrusion of feed raw materials from post-harvest waste.

The Dependence of Short-Circuit Current in a Transistor Inverter on the Parameters of an Electric Circuit

In the course of the operation of power transistor converters of electric energy, various emergency situations are possible, e.g., a short circuit in the load circuit. The rate of increase in the short-circuit current and its amplitude are affected by the parameters of electric circuit (inductance, power supply voltage of the inverter, control voltage across the gate), as well as by the properties of transistors. A method for preliminary estimation of the short-circuit current and rate of its increase at the stage of designing a converter has been suggested in the paper. This method is based on the theory of planning a multifactor experiment. Calculations of the aforementioned parameters for an inverter with the given technical characteristics have been carried out. A comparison of the results of calculation and physical layout has shown that the suggested approach can be used in the design of any electric energy converters in power semiconductor devices.

Mathematical Model of Optimization of Controlled Parameters of the Plasma Surfacing Technological Process of Wear-Resistant Coatings

The dependence of the optimization parameter, which is selected as the clearance of penetration of the base metal of a restored product, is related to several factors: the plasma torch arc current, plasma torch oscillation amplitude, plasma torch displacement speed. It is studied using the methods of mathematical planning of a multifactor experiment and processing the results obtained. As a result of mathematical calculations, the regression equation is obtained in the form of a first-order polynomial characterizing the contribution of each factor to the process of the deposition of wear-resistant plasma surfacing coatings.

INVESTIGATIONS RESULTS OF CHANGE IN TORQUE OF WORK OF SAFETY CLUTCH

In the article the overload clutch design, which makes it possible to increase the efficiency of screw conveyors in extreme conditions. A test bench has been developed and made in order to determine the optimum engineering data and operation conditions of a screw conveyer if an operating device is overloaded. In order to determine the intensity of the influence of such factors as a slope angle of an operating device relative to a horizon, the frequency of the rotation of an operating device and the rate of increase in the moment of resistance on the value of a torque of on a drive shaft, which arises when moving bulk and lump cargo a multifactor experiment has been conducted. As a result of the calculations the dependencies of the response surfaces of the optimization parameter and the two-dimensional section of response surfaces for the visual display of the results of the experimental investigation.

Исследования повышения несущей способности грунтов оснований методом цементации

The review of soil types prevailing in Western Siberia of the Russian Federation is presented. The compositions and physical and mechanical properties of soils are analyzed. Special attention is paid to loess subsidence soils. The problem of obtaining a homogeneous cement-ground mixture is formulated and set. The technological scheme of production of cement-ground piles of foundations of buildings and structures by drilling-mixing method with mechanical activation is considered. Considers methods of strengthening the loess subsidence of soils. Methods for studying the properties of cement-based piles of foundations of buildings and structures are formulated. A multi-factor experiment was conducted to evaluate the parameters that affect the properties of cement-based piles. Based on the research results, conclusions and recommendations are formulated.

The Results of the Laboratory Studies of Harvesting the White Lupine by a Stripper Header with Fingers for Large Seed Crops

Introduction. Agricultural machinery and devices used for harvesting white lupines do not provide a complete collection of seeds, which leads to the violation of agricultural requirements for the harvesting of leguminous crops. It is necessary to find new technological and technical solutions to reduce losses of seeds during this process. The most perspective solution to the problem of white lupine harvesting is the application of industrial flow line technology together with the improvement of the method to comb standing plants by a stripper header. Materials and Methods. The article presents the design of a laboratory setup with experimental working bodies, which allows simulating the process of harvesting white lupines by separating the seed part of plants in the field. The empirical method based on the theory of multi-factor experiment was used to substantiate the parameters and operating modes of the stripper header with fingers for large seed crops. The algorithm and results of experimental studies to determine the completeness of seed collection are presented. Results. The results of the laboratory studies of the stripper header with fingers for largeseeded crops to determine the qualitative indicators for the completeness of the collection of white lupine seeds are presented. It is determined that the maximum completeness of seed collection is 99.5%. Discussion and Conclusion. In studying the technological process of harvesting white Degas lupine seeds by a combing header with fingers for large-seeded crops under laboratory conditions, the physical and mechanical properties of plants were experimentally studied, their morphological characteristics were clarified, and the regimen-technological parameters of the harvesting header were determined to ensure seed loss within agrotechnical requirements (0.5%).

Climate change and defoliation interact to affect root length across northern temperate grasslands

Abstract Grassland plants, especially their root systems, are dynamic and can buffer changes resulting from exposure to multiple stressors; however, the interactive stressor effects on root dynamics and associated above‐ground growth are poorly understood. Here, we examine the effects of changed precipitation and air temperature, and defoliation intensity on root length dynamics and above‐ground biomass using the third year data from a multifactor experiment conducted across three northern temperate grasslands. We found that root length was more sensitive to the changes in environmental and management conditions than root mass, demonstrating the importance of root length as an indicator of rapid root system changes. Across all sites, warming, altered precipitation and defoliation intensity interacted to affect root length while above‐ground biomass was only affected by defoliation intensity, indicating that the root system was more responsive than above‐ground biomass when climatic conditions change. Overall, drought reduced root length, particularly under low defoliation intensity, as well as in combination with warming and heavy defoliation, highlighting the risk of additive effects of such environmental stresses. Across unclipped plots, above‐ground biomass was positively associated with total root length, the latter of which further interacted with precipitation, to affect above‐ground biomass. Compared to defoliated communities, non‐defoliated plant communities exhibited a greater ability to maintain above‐ground biomass under drought conditions via increases in root system efficiency (the amount of above‐ground biomass produced per unit of root length invested). Our results highlight the rapid change of root length in the face of interactive stressors. We postulate that the degree of stability in above‐ground biomass is driven by the altered root system dynamics or species turnover. Future studies are warranted that more directly assess how root length responses under climate change impact other important plant traits in grasslands. A free Plain Language Summary can be found within the Supporting Information of this article.

Experimental investigation of impact of injury measures on the protection screens of combat armoured vehicles

In order to evaluate the relative properties of the protective screen to the striking energy of the means of defeat, an experimental study was conducted, which allowed to test the hypothesis regarding the protection of the combat armoured vehicles against the means of defeat which, under the action of kinetic energy, destroy the armoured obstacle. Based on the data obtained during the experimental study, a mathematical model was constructed that describes the punching momentum of the protective screen. The use of this model makes it possible to calculate the energy losses caused by deformation and destruction of the obstacle. Built as a result of the multifactor experiment, the regularity of the impact of the means of defeat on the protective screen takes into account the speed of the means of defeat, the angle of encounter of the means of defeat with the protective screen, the thickness of the front and back layer and the hardness of the means of defeat.

Systems Analysis of the Efficiency of Imitation Processes of the Chemical Immobilization of Mercury in Waste Using Multivariant Visualization Tools

A methodology has been proposed and multifactor experiments have been performed to determine the effectiveness of simulation processes of the chemical immobilization of mercury in wastes implemented using the principles of green chemistry and taking into account various external conditions: the duration of interaction between mercury and sulfur, the amount of sulfur, the presence of water, and using methods to ensure constant updating of the contact area of phases (grinding of the reaction mixture: manually and with ball or vibration mills). As a result of a systems analysis of the results of simulating multifactor experiments using multivariant visualization tools of large data sets in the form of various diagrams (petal, ruled, bubble, and thermal), the following was established: the possibility of chemical immobilization for 90 min more than 95 wt % metallic mercury in contact with elemental sulfur with an initial mercury content of about 10 wt %, a stable immobilization result of 95 wt % or more mercury is achieved with an excess of sulfur of 3 g per 1 g of mercury and the reaction in a vibration mill, and the presence of a small amount of water (no more than 50 wt % of the weight of the reaction mass) positively affects the process of immobilization.

Mathematical modeling of an experiment for the growth of chia seeds sprouts (Salvia hispanica L.)

World Health Organization (WHO) has reported that more than 80% of the population in developing countries uses herbal medicine. Modern technologies open up the possibility of controlling the cultivation of medicinal plants for commercial use. The combination of various methods of controlled cultivation is a high-tech and capital-intensive direction for the development of the agricultural industry in Russia. This article considers the selection of optimal conditions for growing of chia seeds sprouts as a multifactor experiment with three incoming factors at two levels. For this study 100 grains of dark varieties of chia seeds (Salvia hispanica L.) purchased from Era Green were used. The 3 major incoming factors include moisture (3, 4 and 5 ml of added water), the temperature (20, 25 and 30 °C), and the light (expose duration for 0, 12 and 24 h) under LED lamps with peaks at 440-450 nm (blue spectrum) and 660 nm (red spectrum). Using different factors, we found that the speed of germination and the seedling vigor were considerably improved. This multifactor model helps to establish more reliable information on the rational ways for obtaining chia seeds sprouts in the conditions of controlled cultivation with high yield.