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1

Comparative study for deriving stagedischarge - sediment concentration relationships using soft computing techniques

Sihag P., Sadikhani M. R., Vambol V., Vambol S., Prabhakar A. K., Sharma N.

Journal of Achievements in Materials and Manufacturing Engineering

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2021

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Vol. 104, nr 2

57--76

EN

Purpose: Knowledge of sediment load carried by any river is essential for designing and planning of hydro power and irrigation projects. So the aim of this study is to develop and evaluating the best soft-computing-based model with M5P and Random Forest regressionbased techniques for computation of sediment using datasets of daily discharge, daily gauge and sediment load at the Champua gauging site of the Upper Baitarani river basin of India. Design/methodology/approach: Last few decades, the soft computing techniques based models have been successfully used in water resources modelling and estimation. In this study, the potential of tree based models are examined by developing and comparing sediment load prediction models, based on M5P tree and Random forest regression (RF). Several M5P and RF based models have been applied to a gauging site of the Baitarani River at Odisha, India. To evaluate the performance of the selected M5P and RF-based models, three most popular statistical parameters are selected such as coefficient of correlation, root mean square error and mean absolute error. Findings: A comparison of the results suggested that RF-based model could be applied successfully for the prediction of sediment load concentration with a relatively higher magnitude of prediction accuracy. In RF-based models Qt, Q(t-1), Q(t-2), S(t-1), S(t-2), Ht and H(t-1) combination based M10 model work superior than other combination based models. Another major outcome of this investigation is Qt, Q(t-1) and S(t-1) based model M4 works better than other input combination based models using M5P technique. The optimum input combination is Qt, Q(t-1) and S(t-1) for the prediction of sediment load concentration of the Baitarani River at Odisha, India. Research limitations/implications: The developed models were tested for Baitarani River at Odisha, India.

2

Control of the workplace environment by physical factors and SMART monitoring

Kruzhilko O., Polukarov O., Vambol S., Vambol V., Khan N. A., Maystrenko V., Kalinchyk V. P., Khan A. H.

Archives of Materials Science and Engineering

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2020

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Vol. 103, nr 1

18--29

EN

Purpose: To develop and implementation in practice an algorithm for smart monitoring of workplace environmental physical factors for occupational health and safety (OSH) management. Design/methodology/approach: A brief conceptual analysis of existing approaches to workplace environmental physical factors monitoring was conducted and reasonably suggest a decision-making algorithm to reduce the negative impact of this factors as an element of the OSH management system. Findings: An algorithm has been developed that provides continual improvement of the OSH management system to improve overall labour productivity and which has 3 key positive features: (1) improved data collection, (2) improved data transfer and (3) operational determination of the working conditions class. Research limitations/implications: The implementation of the proposed algorithm for substantiating managerial decisions to reduce the negative impact of workplace physical factors is shown by the example of four workplace environmental physical factors in the products manufacture from glass. Practical implications: If management decisions on the implementation of protective measures are taken in accordance with the proposed monitoring algorithm, these decisions will be timely and justified. This makes it possible to reduce the time of the dangerous effects of physical factors on the health of workers and reduce the level of these factors to improve working conditions. That is, an algorithm is proposed that provides continuous improvement of the OSH management system to increase overall labour productivity. Originality/value: Current monitoring of workplace environmental physical factors values are carried out in accordance with the justified monitoring intervals for each factor that provides the necessary and sufficient amount of data and eliminates the transfer of useless data.

3

Justification of the most rational method for the nanostructures synthesis on the semiconductors surface

Suchikova Y., Vambol S., Vambol V., Mozaffari N., Mozaffari N.

Journal of Achievements in Materials and Manufacturing Engineering

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2019

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Vol. 92, nr 1-2

19--28

EN

Purpose: of this paper is to justification the most rational method for the nanostructures synthesis on the semiconductors surface, which is capable of providing high quality synthesized nanostructures at low cost and ease of the process. Design/methodology/approach: The choice of the optimal method of synthesis was carried out using the hierarchy analysis method, which is implemented by decomposing the problem into more simple parts and further processing judgments at each hierarchical level using pair comparisons. Findings: The article describes the main methods of synthesis of nanostructures, presents their advantages and disadvantages. The methods were evaluated by such criteria as: environmental friendliness, efficiency, stages number of the technological process, complexity, resources expenditure and time and effectiveness. Using the hierarchy analysis method, has been established that electrochemical etching is the most important alternative, and when choosing a nanostructures synthesis method on the semiconductors surface, this method should be preferred. Such studies are necessary for industrial serial production of nanostructures and allow reducing expenses at the realization of the problem of synthesis of qualitative samples. Research limitations/implications: In this research, the hierarchy analysis method was used only to select a rational method for synthesizing nanostructures on the semiconductors surface. However, this research needs to be developed with respect to establishing a correlation between the synthesis conditions and the nanostructures acquired properties. Practical implications: First, was been established that the optimal method for the nanostructures synthesis on the semiconductors surface is electrochemical etching, and not lithographic or chemical method. This allowed the theoretical and empirical point of view to justify the choice of the nanostructures synthesis method in the industrial production conditions. Secondly, the presented method can be applied to the synthesis method choice of other nanostructures types, which is necessary in conditions of resources exhaustion and high raw materials cost. Originality/value: In the article, for the first time, the choice of the nanostructures synthesis method on the semiconductors surface is presented using of paired comparisons of criteria and available alternatives. The article will be useful to engineers involved in the nanostructures synthesis, researchers and scientists, as well as students studying in the field of "nanotechnology".

4

Use of machine learning algorithm for the better prediction of SR peculiarities of WEDM of Nimonic-90 superalloy

Singh Nain S., Sai R., Sihag P., Vambol S., Vambol V.

Archives of Materials Science and Engineering

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2019

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Vol. 95, nr 1

12--19

EN

Purpose: With the end goal to fulfil stringent structural shape of the component in aeronautics industry, machining of Nimonic-90 super alloy turns out to be exceptionally troublesome and costly by customary procedures, for example, milling, grinding, turning, etc. For that reason, the manufacture and design engineer worked on contactless machining process like EDM and WEDM. Based on previous studies, it has been observed that rare research work has been published pertaining to the use of machine learning in manufacturing. Therefore the current research work proposed the use of SVM, GP and ANN methods to evaluate the WEDM of Nimonic-90. Design/methodology/approach: The experiments have been performed on the WEDM considering five process variables. The Taguchi L 18 mixed type array is used to formulate the experimental plan. The surface roughness is checked by using surface contact profilometre. The evolutionary algorithms like SVM, GP and ANN approaches have been used to evaluate the SR of WEDM of Nimonic-90 super alloy. Findings: The entire models present the significant results for the better prediction of SR peculiarities of WEDM of Nimonic-90 superalloy. The GP PUK kernel model is dominating the entire model. Research limitations/implications: The investigation was carried for the Nimonic-90 super alloy is selected as a work material. Practical implications: The results of this study provide an opportunity to conduct contactless processing superalloy Nimonic-90. At the same time, this contactless process is much cheaper, faster and more accurate. Originality/value: An experimental work has been reported on the WEDM of Udimet-L605 and use of advance machine learning algorithm and optimization approaches like SVM, and GRA is recommended. A study on WEDM of Inconel 625 has been explored and optimized the process using Taguchi coupled with grey relational approach. The applicability of some evolutionary algorithm like random forest, M5P, and SVM also tested to evaluate the WEDM of Udimet-L605.The fuzzy- inference and BP-ANN approached is used to evaluate the WEDM process. The multi-objective optimization using ratio analysis approach has been utilized to evaluate the WEDM of high carbon & chromium steel. But this current research work proposed the use of SVM, GP and ANN methods to evaluate the WEDM of Nimonic-90.

5

Theoretical study of food contamination mechanisms by melamine and hazard of melamine for health

Ziarati P., Tamaskoni-Zahedi M., Mostafidi M., Shirkhan F., Vambol S., Vambol V.

Journal of Achievements in Materials and Manufacturing Engineering

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2018

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Vol. 89, nr 2

73--84

EN

Purpose: The purpose of this investigation is to theoretical study of food contamination mechanisms by melamine and hazard of melamine for health. This purpose is justified as follows. A high percentage of nitrogen has caused the abuse of this chemical, because this amount of nitrogen brings about the properties of decomposition of protein molecules into this material, as a result of the increase in melamine in foods. The primary issues discussed are related to o introduce melamine and its sources to the potential of exposure to melamine and to address the risks of this hazardous material and enhance the safety of food products. Design/methodology/approach: The investigation was carried out using analytical analysis. Melamine accumulates in the body of humans and has different effects. The presence of melamine at a very low level is also dangerous for children, and the food safety incidents that occurred in 2008 were due to the presence of melamine in children's infant formula in China, has raised concerns about food security around the world. Findings: As a result analytical research we have this conclusion. Melamine is a chemical compound that is widely used in industry and especially in the production of packaging materials. Reducing the risk to human health can be achieved through the combined use of three factors: using proper control programs to prevent melamine from getting into food, preventing the migration of melamine in food and using no melamine detergents. Research limitations/implications: The investigation was carried out on the basis of open sources of information on the chemical properties of melamine, its presence in household and other materials and its ability to interact with organic media. Practical implications: The results of this study can be recommended to the Ministry of Health and the Ministry of Industry for the development of control programs to prevent melamine from getting into food. Originality/value: The main problem of food pollution by melamine is that this substance is contained in most packaging materials. And a study of the mechanisms the migration of melamine in food and a generalization of the results on the methods for determining melamine in food will help solve the problem of unhealthy food.

6

Substantiation of expedience of application of high-temperature utilization of used tires for liquefied methane production

Vambol S., Vambol V., Kondratenko O., Koloskov V., Suchikova Y.

Journal of Achievements in Materials and Manufacturing Engineering

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2018

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Vol. 87, nr 2

77--84

EN

Purpose: The purpose of this investigation is to substantiate by means of numerical simulation the expedience of high-temperature utilization of used tires with subsequent methanation of fuel gases and separation of multicomponent hydrocarbon mixtures to drain the liquefied methane. Design/methodology/approach: The investigation was carried out by means of numerical simulation. In mathematical description of gas processes relations of thermodynamics and heat and mass transfer were used. To determine the coefficients of thermal and physical parameters of working bodies the Peng-Robinson equation of state was used through the computer program REFPROP. The system of equations is represented as the interrelations between the functional elements according to the principle "output from the element A – input into the element B". Its solution was obtained by the method of successive approximations, namely by the Newton-Raphson iteration method. Using this method we have determined the values of temperature, pressure, mass flow rate and mass content of the hydrocarbon gas mixture components in each reference cross-section of the power facility. Findings: As a result of numerical simulation, it is determined that when the multicomponent hydrocarbon mixtures are separated, three flows of energy resources may be obtained: with a high mass content of methane of 91.5% and 83.4%, which may be used as motor fuel, and a gas flow suitable for maintaining the process of waste gasification. However, to remove heat in the condenser of the rectification column, it is necessary to use expensive liquid nitrogen. The cost of methane production may be reduced if the condenser is removed from the rectification column. However, such approach reduces the overall yield of commercial products almost in four times and significantly reduces the methane with the third product (molar percentage of 35%). Research limitations/implications: The investigation was carried out for the material of used tires without a metal frame. Practical implications: The implementation of the technology of high-temperature recycling of used tires gives the opportunity to use the generated synthetic gas to maintain the process of utilization, and gives the opportunity to produce liquefied methane, suitable for storage. Originality/value: The main problem of high-temperature recycling of tires is the emission of toxic gas to the atmosphere. It is proposed to allocate methane energy resource from this gas. For the first time an attempt was made to justify the expedience of the technology of high-temperature utilization of tires for liquefied methane production.

7

Physical modelling of changes in the energy impact on a worker taking into account high-temperature radiation

Ragimov S., Sobyna V., Vambol S., Vambol V., Feshchenko A., Zakora A., Strejekurov E., Shalomov V.

Journal of Achievements in Materials and Manufacturing Engineering

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2018

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Vol. 91, nr 1

27--33

EN

Purpose: The purpose of this investigation is development of an experimental installation and definition the intensity of thermal irradiation at workplaces to ensure safety under condition of increased thermal radiation. This purpose is justified as follows. Human health and well-being depend to a large extent on conditions of the internal environment of the premises, which affect the heat exchange of workers with the surrounding surfaces. With this the spectral composition and intensity of irradiation are also important for assessing the effect of thermal radiation. Design/methodology/approach: The investigation was carried out using special experimental device. Uniformly lit semitransparent screen was used as a source of thermal radiation source. We used photo film with heat flow sensor ДТП 02 – ДТП 03 developed by Institute of Engineering Thermophysics under Academy of Science of Ukraine as model of the elementary surface of human body. Findings: Based on results of conducted research and optimization, we propose protective compositors that are nonflammable. This fact allows the increase in safety of facilities during operation and evacuation routes in emergency case due to high-temperature effects. Research limitations/implications: In this study, was focused on the dependence of the local angular coefficient of irradiation and maximum thermal loads, as well as the transition from indirect measurements to direct ones. This allows us to predict working conditions by the thermal factor in the workplace. Practical implications: The results of this study can be recommended to the Ministry of Health and the Ministry of Industry for the development to reduce the incidence of occupational morbidity among workers who work under conditions of exposure of thermal radiation. Originality/value: It was disclosed that it is possible to determine the distance to the source of thermal radiation from the point of measurement and the angle at which the source of thermal radiation is visible with high accuracy. Moreover, measurement point may be located at a distance safe for the researcher.

8

Investigation of the porous GaP layers' chemical composition and the quality of the tests carried out

Vambol S., Vambol V., Suchikova Y., Bogdanov I., Kondratenko O.

Journal of Achievements in Materials and Manufacturing Engineering

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2018

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Vol. 86, nr 2

49--60

EN

Purpose: The purpose of this study is to establish the quality of tests for determining the chemical composition of the porous surface obtained by the method of electrochemical etching, based on the indicators of convergence and reproducibility of the results. Design/methodology/approach: The method of electrochemical etching was used to obtain layers of porous gallium phosphide, which can be used as buffer layers for nitrides formation on their basis. Por-GaP was formed in a solution of hydrofluoric acid at a current density of j =100 mA/cm2, etching was carried out for 20 minutes. The resulting structures sulfide passivation was carried out, thus avoiding the formation of an oxide film on the samples surfaces. For this purpose, porous gallium phosphide samples were kept in a sulfide solution for 10 minutes and dried in a stream of nitrogen. The chemical composition of the porous GaP surface layers has been investigated. To do this, the method of electronprobe INCA Energy microanalysis was used. The research was carried out on the entire surface of the sample in order to calculate the total spectrum of the elemental composition of the sample under study. Findings: It was established that during anodizing, the stoichiometry of the crystals investigated did not shift significantly towards the excess of gallium atoms. Oxygen is present at an insignificant concentration of 0.3%. This indicates the effectiveness of conducting the sulfide passivation of the sample surface following the electrochemical treatment. The presence of fluorine atoms that appeared on the surface as a result of the reaction with the electrolyte during etching, is observed in extremely low concentration. Experimental studies have shown that the sample chosen can be used as a standard enterprise sample when analyzing the chemical composition of the surface of porous gallium phosphide due to its convergence, reproducibility, homogeneity. In addition, the given method for determining the standard sample can be applied to other porous semiconductors. Conducting such studies is an important technological task that will allow us to create a series of standard samples of porous semiconductors of A3B5 group. Research limitations/implications: The research was carried out for porous gallium phosphide samples synthesized in the solution of hydrofluoric acid, though, carrying out of similar experiments for por-GaP obtained in other conditions, is necessary. Practical implications: The studies of the reproducibility and convergence of the experiment have an important practical significance, since it is the reproducibility of the experiment results that is the main problem to modern material science, all the more to nanoengineering. Therefore, the technique proposed, will allow the synthesis of por-GaP layers with adjustable properties, will facilitate their widespread implementation in the real sectors of industry. The obtained porous layers can be used as standard samples. Originality/value: The main problem in the nanostructures synthesis is the adjustability of properties. The technique presented allows to form stable layers of the porous gallium phosphide with the surface chemical composition known in advance. In addition, carrying out the sulfide passivation allows to stabilize por-GaP properties, which is an important process task. For the first time, a study of the presented technique as to convergence, reproducibility and homogeneity, was conducted.

9

Substantiation of the choice of the cutter material and method of its hardening, working under the action of friction and cyclic loading

Sokolov D., Sobyna V., Vambol S., Vambol V.

Archives of Materials Science and Engineering

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2018

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Vol. 94, nr 2

49--54

EN

Purpose: The main problem with the use of rescue instruments during emergency response is the low strength of the tool’s cutting edge. The consequence of this is the low efficiency of rescue operations. The purpose of this study is to substantiate experimentally the choice of material for the tool’s cutting edge and the method of surfacing it on the cutter of a hydraulic tool, operating under the simultaneous influence of friction and cyclic loading. Design/methodology/approach: The choice of material was carried out by the way of analytical analysis with subsequent experimental verification. For this purpose, specially made samples of cutters from various grades of alloyed steel were used. With these cutters the steel rod Ø 12 mm made of St3 steel was cut; the number of cutting cycles preceding blunting or destruction of the cutting edge of the tool was counted. Analytical study of the possibility of cutter’s surface hardening by fusing the cutting edge onto it was carried out by the way of analyzing scientific research in the area of improving the technical characteristics of a mechanized hydraulic tool. Findings: It has been experimentally established that Steel 30HGT gives the greatest number of working cycles before blunting, while steels of the manufacturer (Steel 65G and Steel 12M) are destroyed in 180 and 200 working cycles, respectively. Other steels are not destroyed, but can stand fewer number of cutting cycles. To reduce the cost and increase the efficiency of rescue operations, it is proposed to perform surface hardening of the tool cutter by fusing the cutting edge made of Steel 30 HGT steel (analogs: in Germany – 30MnCrTi; in the Czech Republic – 14231). Analytical research has shown that manual arc welding as a method of welding metals is widely tested, reliably reproducible, allows for surfacing in any conditions outside the fabrication facility and is carried out with non-bulky equipment. This will increase the life of the hydraulic rescue tool. Research limitations/implications: The study was conducted for steels that meet the requirements of national standards. Practical implications: Equipping rescue workers with a mechanized tool that has been upgraded by the proposed method improves the efficiency of rescue operations in emergency situations. Originality/value: It is proposed to increase the strength and reliability of a mechanized tool for rescue operations. For the first time, an attempt to substantiate the choice of method for hardening the cutting) edge of an instrument by applying reliably reproducible technologies was made.