Environmental protection of a coal-mining region

Research objective is to substantiate the relevance of mining transition to eco-friendly technologies of subsurface use. Methods of research include analyzing theory and practice of environmental technologies application and carrying out a multifactor experiment. Results. An efficiency criterion for mineral resources extraction technologies is proposed that involves reducing the effect made by the by-products of mining and processing enterprises on the state of the environment. The problem is considered of minimizing the environmental damage from storing silt coal in dumps and storages by utilizing their components. The mechanism of environmental pollution has been formulated. Aspects of metal recovery from beneficiation tailings in a disintegrator mill are investigated. A reduced threat to living matter is predicted by implementing the concept of radical waste-free processing of substandard mineral raw materials. The need to improve the processes of crushing, fine grinding, and classification of minerals in mills to reduce the waste of coal production, harmful to the environment, is noted. Conclusions and scope of the results. Deteriorated conditions of mineral deposits development raise the risk of man-made impact on the environment in coal-mining regions. The global human population grows resulting in increased resources production to respond to resource needs. The growing threat to living matter can be reduced by radical measures, the non-waste processing of substandard mineral raw materials being the priority. The research results can be helpful in the development of deposits of solid metal-containing technologically exposed ores

Technological factors influence on the antifriction coatings quality

The conditions for the antifriction coatings formation during finishing antifriction non-abrasive treatment (FANT) are analyzed. The requirements for this kind of coatings and the main criteria for assessing their quality are noted. A relationship has been established between the quality of the coating obtained with FANT and the technological factors that determine the conditions for contacting the tool with the treated surface. It is proved that the shape and size of microroughnesses of the treated surface determine the efficiency of the microcutting process and filling the microcavities with the rubbed material. Technological factors influence on the coating quality was investigated during FANT by implementing a multifactor experiment, as a result of which a connection was established between the technological parameters of the process (total friction path, load on the tool), as well as the length of the supporting surface with indicators characterizing the coating quality. Statistical models were obtained for mass transfer of antifriction material, area (continuity) of the coating and surface roughness at natural values of the factors, which made it possible to establish the studied factors influence on the optimization parameters. The analysis of the experimental scattering graphs made it possible to clarify the nature of the factors changes and analyze their mutual influence on the optimization criteria. Taking into account the inversely proportional relationship of the optimization criteria, the achievement of their maximum values at the same time is impossible, therefore, the values are taken according to the final result of the FANT process. The range of the studied factors values is established, the regularities of their change are substantiated from the point of view of the selected optimization criteria. Determination the rational values of the FANT process technological parameters will improve the antifriction coatings quality obtained by a friction-mechanical method.

INVESTIGATION OF SUBSTRATE MIXING PROCESS IN ROTATING DRUM REACTOR

The results of the research on the influence of the drum type reactor design-technological parameters and the substrate`s physical-chemical parameters on the substrate`s components mixing evenness, that influence the quality of the received compost, are presented in this paper. By the method of the multifactor experiment rational values of the drum rotation speed, the blades (mounted on the inner drum surface) angle and the substrate`s moisture content are defined at which the components distribution homogeneity in the substrate reaches maximal value. The abovementioned, in turn, provides high compost quality by the agrichemical indices. The recommendations are given to pick the design parameters and operational modes of the drum type reactor.

Experimental Stand Movable Module for Determining the Traction-Linked Properties of Wheel Engines and the Results of Laboratory Researches for Determining the Traction Force of Two-Wheel Tractors

Introduction. Farmers make extensive use of two-wheel tractors equipped with traction and drive interchangeable units. Two-wheel tractors are required to move evenly with minimal slip of the drive wheels on the soil. The tractive force on the drive wheels of the tillage unit is the decisive power factor in this case. An objective traction force value can be measured only by carrying out experimental studies. Materials and Methods. To determine the traction force on the drive wheels of the twowheel tractor, the design of the experimental stand was proposed and substantiated (RF patent for useful model No. 188610 “Movable module of the test stand”), and a methodology for planning and conducting a multifactor experiment to determine the traction force was developed. Results. As a result of the laboratory tests the calculation dependencies of the tractive force on the drive wheels of the Neva MB23-MultiAGRO Pro two-wheel tractor were obtained. Soil conditions, design and technological parameters, operating modes of the two-wheel tractor, and rolling resistance forces were taken into account. Discussion and Conclusion. The use of the developed regression models of the traction force under the condition of ensuring uniform movement with the minimum permissible slipping of the driving wheels of the two-wheel tractor on the soil will allow obtaining the permissible values of the two-tractor motion speed and form the zones of its most effective functioning.

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.

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.

APPLICATION OF THE GRAVITY SEARCH METHOD TO MINIMIZE THE COST OF CONDUCTING A MULTIFACTOR EXPERIMENT

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.

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.

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.