Eastern-European Journal of Enterprise Technologies
http://journals.uran.ua/eejet
<p><span lang="EN-US">Terminology used in the title of the "Eastern-European Journal of Enterprise Technologies" - "enterprise technologies" should be read as "industrial technologies". <strong>"Eastern-European Journal of Enterprise Technologies"</strong> publishes all those best ideas from the science, which can be introduced in the industry. Since, obtaining the high-quality, competitive industrial products is based on introducing high technologies from various independent spheres of scientific researches, but united by a common end result - a finished high-technology product. Among these scientific spheres, there are engineering, power engineering and energy saving, technologies of inorganic and organic substances and materials science, information technologies and control systems. Publishing scientific papers in these directions are the main development "vectors" of the "Eastern-European Journal of Enterprise Technologies". Since, these are those directions of scientific researches, the results of which can be directly used in modern industrial production: space and aircraft industry, instrument-making industry, mechanical engineering, power engineering, chemical industry and metallurgy.</span></p><p><span lang="EN-US">Therefore, the scientists, associated with modern production, have the opportunity to participate in technology transfer to industry, publishing the results of their applied scientific researches. Industrialists, in turn, can draw scientific and practical information from the journal - each in their direction:</span></p><ul><li>specialists in management and computer science - from volumes "Applied Information Technologies and Control Systems", "Mathematics and Cybernetics - Applied Aspects";</li><li>mechanical and design engineers - from the volume "Applied Mechanics";</li><li>production engineers - from volumes "Mechanical Engineering Technology", "Applied Physics", " Materials Science", "Technology of organic and inorganic substances and the Ecology";</li><li>production and power engineers - from the volume "Energy-saving technology and equipment".</li></ul><p><span lang="EN-US">The goal of the journal is to eliminate the gap, which occurs between the rapidly emerging new scientific knowledge and their introduction in the industry, which requires much more time. Industrial enterprises are active subscribers to the "Eastern-European Journal of Enterprise Technologies", and production engineers check the practical value of those scientific and technological ideas, which are recommended for implementation by scientists-authors of the ''Eastern-European Journal of Enterprise Technologies".</span></p><p><span lang="EN-US">The objective of the journal in achieving the goal is forming a "scientific component" of modern technologies transfer from science to industry. Therefore, in the papers, published in the journal, the emphasis is placed on both scientific novelty, and practical value.</span></p>PRIVAT COMPANY "TECHNOLOGY CENTER"en-USEastern-European Journal of Enterprise Technologies1729-3774<p>Our journal abides by the CREATIVE COMMONS copyright rights and permissions for open access journals.</p><p>Authors, who are published in this journal, agree to the following conditions:</p><p>1. The authors reserve the right to authorship of the work and pass the first publication right of this work to the journal under the terms of a Creative Commons Attribution License, which allows others to freely distribute the published research with the obligatory reference to the authors of the original work and the first publication of the work in this journal.</p><p> 2. The authors have the right to conclude separate supplement agreements that relate to non-exclusive work distribution in the form in which it has been published by the journal (for example, to upload the work to the online storage of the journal or publish it as part of a monograph), provided that the reference to the first publication of the work in this journal is included.</p>Analysis of detection of ecological hazard based on computing the measures of current recurrence of ecosystem states
http://journals.uran.ua/eejet/article/view/147508
<p>Analysis of the early detection of an environmental hazard in ecosystems was performed. New measures of the current recurrence of states that allow their use for the early detection of an environmental hazard in ecosystems were proposed. Calculations of the measures under consideration are based on the distribution of the known measure of global recurrence for the case of the calculation of measures of current recurrence in moving square windows. In this case, one of the measures under consideration is based on the implementation of a moving square window along the main diagonal of the recurrent plot of state. Another measure is based on the use of a moving window of the specified size along the horizontal (vertical) axis of recurrence plots. The latter made it possible to obtain a constructive current measure for calculation of recurrence to identify dangerous states in ecosystems based on the temporal localization of zero recurrence of states at minimum sizes of a moving window. In accordance with the proposed measures of current recurrence, the possibilities of using the measures for the early identification of an environmental hazard for gas medium with the ignition center of combustible material, such as alcohol, were analyzed. It was shown that the window measure of current recurrence at a horizontal moving small-size window is the most suitable of the considered measures. It was found that for such a measure, window sizes must be in the range from 5×5 to 15×15 counts. In this case, the values of region ε of neighborhood for the considered states must be selected in the range from 0.01 to 0.15. It was determined theoretically and experimentally that the specified measure of current recurrence of states with a horizontally moving window can be considered as a structural current measure of recurrence to ensure a reliable early detection of hazardous states in different ecosystems.</p>Boris PospelovYuliya DanchenkoIlgar Firdovsi DadashovStanislav SkliarovStella GornostalOleksandr Cherkashyn2018-11-162018-11-16512 (95)10.15587/1729-4061.2018.147508Determination of stresses and strains in the shaping structure under spatial load
http://journals.uran.ua/eejet/article/view/147195
<p>The computational model of the machine – environment system, taking into account the mutual influence of the working body and compaction mixture was developed. It is based on the condition of determining the contact forces of interaction between the subsystems and estimation of the ratio of the time of action and time of wave propagation. This approach is new, since it takes into account the real relationship between the dynamic parameters of the machine and the environment and degree of interaction. The study and determination of stresses and strains in time confirmed the hypothesis of their significant influence on the process. A fundamentally new result was revealed, which consists in the fact that the transition process should take into account the determination of parameters and locations of vibrators. The laws of stress and strain variations during spatial oscillations of the shaping surface were established. Modes of natural oscillations of the system are implemented with higher oscillation amplitudes and correspondingly lower frequency. And this opens up a real opportunity to reduce the energy intensity of the vibration machine. Numerical values of stresses and the nature of their distribution in the shaping surface, depending on the angle of the instantaneous action of the external force of vibrators, the presence of bending and torsional oscillations were obtained.</p><p>So under the condition of two excitation forces, the points of application of which are displaced relative to each other by ½ of the length of the structure, placing the force application points symmetrically at a distance of ¼ of the size of the structure on both sides allowed obtaining cophased and anti-phase directions of stresses and acting external force.</p><p>In calculations of vibration machines using shaping surfaces, it was proposed to take into account output numerical values of the amplitude-frequency mode of the oscillation exciter. Practical recommendations for the rational design of sections of shaping structures were developed and technological parameters were determined. To construct such shaping structures, the installation sites for vibrators were determined. The results obtained can be successfully used in related processes, for example, in the mining industry, as active surfaces for ore transportation, for the transfer of suspensions and solutions in the chemical industry.</p>Ivan NazarenkoViktor GaidaichukOleg DedovOleksandr Diachenko2018-11-132018-11-13512 (95)10.15587/1729-4061.2018.147195Determination of optimal parameters of the pulse width modulation of the 4qs transducer for electriс rolling stock
http://journals.uran.ua/eejet/article/view/143789
<p>Operating modes of the single-phase 4qs transducer with pulse-width modulation as part of the AC electric rolling stock are investigated. The method is developed for determining the PWM parameters, at which the optimum transducer mode in terms of minimizing the reactive power in the “locomotive-traction network” system is implemented.</p>The features of the developed method are the division of the process of determining the optimum PWM parameters into 2 steps. This allows removing unnecessary blocks from the simulation model and reducing the total simulation time. At the first step, the values of the power factor and current of the DC link in the whole range of coefficients of modulation and shift between the network current and the reference sine-wave signal are determined. Further, from the received data array, pairs of values of the PWM parameters, which ensure the highest power factor of the “electric locomotive-traction network” system are allocated and entered into the table system for setting the PWM parameters. At the second step, the dependences of power loss, and, consequently, both the efficiency and total harmonic distortion of the network current on the transducer clock frequency are determined. The determination of power loss is based on the calculation of the energy dissipated for 1 s on the IGBT transistor and snubber resistor depending on instant values of current through themОleksandr DemydovBorys LiubarskyiValerii DomanskyiMarina GlebovaDmytro IakuninAnna Tyshchenko2018-10-312018-10-31512 (95)293810.15587/1729-4061.2018.143789Development of the method to operatively control quality of iron ore raw materials at open and underground extraction
http://journals.uran.ua/eejet/article/view/144003
<p>The main task of the mining industry is to improve the efficiency of extraction and processing of iron ore. One of the main factors contributing to solving the task is determining the content of iron in the ore body at the initial stage of production chain. Traditional methods of chemical analysis that are widely used at present to achieve this goal do not possess a sufficient degree of responsiveness and require about two hours to obtain the results. That typically does not make it possible to properly adjust the parameters of the technological process of ore processing, but only provides for the opportunity to ascertain the status of the production process at the time of sampling.</p><p>Existing methods of accomplishing this task, which possess a sufficient degree of efficiency, are based on the use of direct methods. These include the nuclear-physical (interaction between gamma-radiation and mountain mass), magnetometric (changing the relative magnetic permeability when interacting with magnetic iron), ultrasound (a change in the ultrasonic wave propagation in the examined material) methods.</p><p>In order to improve the accuracy of determining the percentage of a mineral component in the examined mountain mass, in this work we have improved the nuclear-physical method for determining the content of total iron in iron ore lumps. The improvement of the method makes it possible to enhance the accuracy of control over a mineral component in the studied material by 1.5 % by registering not only the gamma quanta reflected from the surface, but the absorbed particles as well. We have experimentally established the sensitivity level (K=1.32‒1.38), which characterizes a change in the intensity of the registered radiation due to a change in the content of iron in the irradiated material. We have also established the level of a statistical error (<0.65 %) in order to ensure the permissible measurement accuracy.</p>Based on a given method, we have proposed an information-measuring system for monitoring, analysis, and forecasting the qualitative characteristics of ore under conditions of an enrichment plant. The application of this system makes it possible for technological personnel to promptly intervene in the production process and to adjust the qualitative-quantitative parameters of oreAlbert AzaryanAndrey GritsenkoAnnait TrachukDmitriy Shvets2018-10-312018-10-31512 (95)131910.15587/1729-4061.2018.144003Development of the Markovian model for the life cycle of a project’s benefits
http://journals.uran.ua/eejet/article/view/145252
<p>This study has improved the standard P5 (Personnel, planet, profit, process, product), which has already been widely applied globally in the practice of project management. However, the standard P5 provides a scheme of the life cycle of projects’ benefits, which makes it possible to represent the lifecycle processes only at the qualitative level. In order to pass to the quantitative estimates, it has been proposed to apply the Markovian chain that maps a phenomenological representation of complex systems without considering their physical character.</p><p>We have constructed a cognitive Markovian model of the life cycle of a project’s benefits using the communications between the states of the project system. The cognitive structure of the life cycle is similar to a directed graph where vertices indicate the state of the system, and links are the communications between them. We have proposed an approach to determining transitional probabilities based on the evaluation of communications, taking into consideration the time costs to perform operations in the form of rules. The character of communications between states s→j in the Markovian chain defines the magnitude of transition probabilities π<sub>sj</sub>. The time costs required for each state are divided into five intervals π<sub>sj</sub>: {0} – no costs; {0.01–0.1} – insignificant time costs; {0.1–0.3} – the lowest level of time costs; {0.3–0.7} – average time costs; {0.7–1.0} – the largest time costs. The logic of choosing values for conditional transition probabilities in the Markovian chain makes it possible to determine data for the simulation of the trajectory of the life cycle of projects’ benefits in the coordinates of the probabilities of states of the system and steps.</p><p>It has been shown that the application of the Markovian chains is rational in order to represent the life cycle of projects’ benefits. An analysis was performed to determine a certain level of technological maturity of the project environment (organization), which corresponds to the totality of values for transition probabilities. We have studied the influence of the level of technological maturity of the project environment (organization) on the projects’ efficiency.</p>Another example of the implementation of the project aimed at forming the positive image of an educational establishment by applying the frontal information communication via television, the press, by taking part in mass political activities, has also revealed positive estimation. The probability distribution at the beginning of the project (V1) and upon its completion (V2) differs significantly. The implementation of the project increased the magnitudes of probabilities of states p7 (Benefit) and p8 (Additional benefit). At the beginning of the project: р7<sup>(V1)</sup>+р8<sup>(V2)</sup>=0.14+0.05=0.19. Upon implementation of the project: р7<sup>(V1)</sup>+р8<sup>(V2)</sup>=0.22+0.08=0.30. The evaluation of this project aimed at positive image formation of an educational establishment showed that the results obtained do not contradict the hypothesis about the possibility of applying the Markovian chains to determine the characteristics of the life cycle of a project’s benefitsVarvara PiterskaOlexii KolesnikovDmytro LukianovKateryna KolesnikovaViktor GogunskiiTetiana OlekhAnatoliy ShakhovSergey Rudenko2018-10-312018-10-31512 (95)303910.15587/1729-4061.2018.145252Influence of elasticity of unbalance drive in vibration machines on its oscillations
http://journals.uran.ua/eejet/article/view/133922
<p>The dynamics of the vibration machine with unbalance vibration exciter taking into account the elasticity of its connection with the asynchronous motor is studied.</p><p>The expression describing torsional oscillations of the elastic coupling in the steady (near-steady) operation of the vibration machine and the formula of the vibratory moment for the machine with plane oscillations of the working body are obtained. The amplitude-frequency characteristics of oscillations of the vibration machine drive using “soft” and “rigid” elastic couplings are constructed. It is shown that resonant oscillations can arise in the vibration machine drive. The nature of changes in the magnitude of the vibratory moment (additional dynamic load on the motor caused by oscillations of both the bearing body of the vibration machine and the elastic coupling), depending on the vibration exciter speed is determined. It is shown that the presence of the elastic coupling in the vibration machine drive in certain operation modes can lead to an increase in the motor load and promotes the appearance of the Sommerfeld effect during start-up. Critical frequencies of the vibration machine drive with unbalance vibration exciter are specified. Recommendations on the choice of natural frequencies of the drive in order to avoid resonant oscillations are formulated.</p><p>By means of computer simulation, the emergence of resonant torsional oscillations of the vibration machine drive during the passage of the natural frequency region and the associated manifestation of the Sommerfeld effect are demonstrated. The effectiveness of the proposed recommendations for reducing drive oscillations is confirmed.</p>The results obtained will allow avoiding resonant oscillations in the vibration machine drive, thereby reducing the dynamic loads in the elements of its design and increasing the reliability and durability of the drive partsNikolay YaroshevichIvan ZabrodetsSergii ShymchukTetiana Yaroshevich2018-10-302018-10-30512 (95)626910.15587/1729-4061.2018.133922Development of procedure for assessing the degree of enviromental hazard from the sources of aquatic environment pollution
http://journals.uran.ua/eejet/article/view/143804
<p>The new procedure for evaluation of the degree of environmental safety of water sites based on the comparison of the influence of separate point sources of sewage discharge was developed. The use of this procedure will make it possible to solve the problem of identifying ecologically dangerous sites and to determine priority directions of aquatic sites protection in the region. The essence of this procedure is to assess the environmental hazard of specific facilities of the national economy taking into account the safety level, the degree of influence on the water quality of an aquatic site, effectiveness of monitoring and the magnitude of anthropogenic load.</p><p>The logical-mathematical model of evaluating the impact of sources of water environment pollution, based on determining the coefficients of conditions of sewage discharge, sewage pollution and the load on an aquatic site, was proposed. The degree of environmental hazard of the sources of pollution of aquatic sites was determined by the value of coefficient of harmful influence of a pollution source on aquatic sites by the five-level scale from "safe" to "extremely hazardous". The designed scale corresponds to the environmental classification of the Water Framework Directive of the EU 2000/60/EU.</p><p>Testing of the developed procedure was performed on an example of the section of a river basin that is typical for territorial production complexes, where the facilities of nuclear power industry, industrial manufacturing and public utilities are located. Based on determining block and total coefficient of harmful influence of the sources of pollution of aquatic sites, we developed the map of ecological hazard of the sources of the river basin pollution. The sources of pollution of aquatic sites were classified by the designed scale. It was established that large enterprises of housing and communal services and the facilities of machine-building industry have the greatest degree of environmental hazard. These facilities belong to class II and are described as "hazardous’. Enterprises of atomic power and hydropower plants belong to class III of hazard − "moderately hazardous".</p>Results of the analysis can be used to develop water resources management strategies and measures to reduce the impact of pollution sources on aquatic sitesNataliya MagasGanna TrokhymenkoVolodymyr Blahodatnyi2018-10-302018-10-30512 (95)566510.15587/1729-4061.2018.143804Analysis of correlation dimensionality of the state of a gas medium at early ignition of materials
http://journals.uran.ua/eejet/article/view/142995
<span lang="EN-US">We have considered the application of the method of nonlinear dynamic systems in order to analyze and detect the structural patterns in the dynamics of increments in the state of a gas medium generated by early ignitions of materials in a non-sealed chamber. The research method is based on analysis of the correlation dimensionality of increments in the state of a gas medium during ignition of materials. We have theoretically justified the method for evaluating the dynamics of correlation dimensionality of increments in the state of a gas medium at ignition. The considered method for CD evaluation is based on the computation of the Grassberger-Procaccia correlation integral, applied to the gas medium state increments using a sliding window with a fixed width. That allowed us to derive a current estimate of CD increments in the state of the gas medium during ignition of flammable materials in a chamber synchronized with the observation data acquisition rate. We have analyzed the dynamics of correlation dimensionality of increments in the state of a gas medium at early ignition of alcohol, paper, wood, and textiles in a simulation chamber. It was established that for the investigated state of the gas medium during ignition of various examined materials, the dynamics of correlation dimensionality is within 0.1 to 0.6. It is noted that this fact testifies to the fractal structure of the considered increments in the state of a gas medium in a chamber and its chaotic dynamics at the emergence of ignition sites of tested materials. In this case, the fractal structure is not the same, suggesting a "transitional chaos" in the examined state of the gas medium. It was established that current estimates of the correlation dimensionality of increments in the state at the time of materials ignition tend to a sharp increase. A given fact can be used to reliably detect early fires indoors. The results obtained are important for the in-depth studying and understanding of patterns in the structure of dynamics of increments in the state of a gas medium at early ignition. It has been shown the increments in the states of a gas medium at premises characterize it as a chaotic dynamic system with a small fractal dimensionality as opposed to the traditional approach assuming a gas medium being either deterministic or random system</span>Boris PospelovVladimir AndronovEvgeniy RybkaRuslan MeleshchenkoStella Gornostal2018-10-302018-10-30512 (95)253010.15587/1729-4061.2018.142995Welded joints geometry testing by means of automated structured light scanning
http://journals.uran.ua/eejet/article/view/145713
<span lang="EN-AU">Nuclear industry in Russia plays an important role in total power generation. At the same time, it is considered to be dangerous in terms of high potential risk in a case of any failure occurrence. Therefore, constant monitoring and quality control is essential on every stage of energy production process, as well as maintenance of the technical quality of the exploited components. For that reason, specified regulatory documents are developed. They provide quality requirements for each component type and regulate inspection procedures. In this paper, welded joints were considered as the controlled object. It is represented that standard quality control methods based on the manual visual inspection are not accurate enough. Therefore, this paper suggests an advanced method of automated optical scanning for misalignment evaluation of welded parts based on structural light technique. Precision improvement was achieved by implementation of a robotic manipulator, which led to the development of the specific calibration technique. Considering that there are no established methodologies for such method the validation experiments were performed. The ability to detect the minimum displacement in accordance with nuclear industry regulatory documents was studied. The results demonstrated that misalignment of 0.47 mm can be measured, and it proves that proposed method can be further implemented for a practical application in nuclear industry</span>German FilippovDmitry SednevYana Salchak2018-10-262018-10-26512 (95)536010.15587/1729-4061.2018.145713Construction of the integrated method to model a system for measuring the density of infrared radiation flows
http://journals.uran.ua/eejet/article/view/145696
<p>We have constructed an integrated method to model the system of measuring the density of flows of infrared radiation based on solving the inverse problems of dynamics using the Volterra equation of the first kind and focusing on solving the problem on dynamic correction. Solving a problem on the structural correction of the dynamic characteristics of the system for measuring the density of flows implies the construction and application in a transforming channel or a circuit in the system of a certain unit. This unit, owing to its specially formed dynamic properties, ensures the best dynamic characteristics of the entire system.</p><p>We have experimentally verified the technique for the compensation for a dynamic error. To this end, the experiments were conducted to measure the density of a non-stationary flow of infra-red radiation with the assigned law of change, which is characteristic of the practical working conditions for receivers. A change in the density of the incident flow of infrared radiation was achieved at the expense of the receiver's rotation around the axis that passes through the middle of its receiving surface, in the flow of the stationary emitter. The result of the experiment is the derived nonlinear approximation of the experimentally obtained transitional characteristic in the form of the receiver's response to the sinusoidal flow of infrared radiation.</p>It should be specifically noted that the results of numerical simulation and the experiment show a satisfactory convergence, which allows us to argue about the correct choice of the model. The developed algorithms are capable to provide a numerical implementation of integrated models and serve as the basis for constructing high-performance specialized microprocessor systems to work in real time. That has made it possible to successfully implement the dynamic correction of the system for measuring flows of infrared radiation and to significantly increase its accuracy. A combined application of the devised method for solving mathematical problems and computer tools would provide an opportunity to improve the efficiency of processes to synthesize and design computational devices for correcting means of measurementAlexander SytnikInga SemkoValentyn TkachenkoKonstantin KlyuchkaSergey Protasov2018-10-262018-10-26512 (95)475210.15587/1729-4061.2018.145696Enrichment on Bangka tin slag’s tantalum and niobium oxide contents through non-fluoride process
http://journals.uran.ua/eejet/article/view/129914
<p>This research explored how non-fluoride solutions including 8M NaOH, 0.8, 1.6 and 2.4 M H<sub>2</sub>SO<sub>4</sub>, and 0.1, 0.4 and 0.8 M HClO<sub>4 </sub>increased the contents of tantalum and niobium oxide through leaching. Before leaching, Bangka tin slag (BTS) was characterized through XRF. The slag was then 900⁰C-roasted, quenched, and dewatered. Next, BTS underwent a sieving process with size classifications of +100, -100+150, -150+200, -200+250, and -250 mesh. After that, the -200+250 mesh slag was leached with 8M NaOH. Then, the leached product was divided into two, one of which was 0.1, 0.4, and 0.8 M HClO<sub>4</sub>-leached and the rest of which was leached with 0.8 M HClO<sub>4</sub> followed by 0, 0.8, 1.6, and 2.4 M H<sub>2</sub>SO<sub>4</sub> at 25⁰C within 2 hours. All the residues characterization used an XRF while that of filtrates used an AAS as well as an ICP-OES. The motives that drive this investigation are the deficit of tantalum supply and its status as one of the technology-critical elements. In addition to that, most of prior investigations enhanced the contents of tantalum and niobium oxide using fluoride acid while this study ventured non-fluoride solutions. The result shows that perchlorate acid followed by sulfuric acid leaching slightly enriches the tantalum and niobium contents. However, this method is the most effective among NaOH, HCIO<sub>4</sub>, and HCIO<sub>4 </sub>followed by H<sub>2</sub>SO<sub>4 </sub>leaching. This finding is a form of scientific effort to maintain the tantalum supply through utilizing worthless waste of tin smelting<em></em></p>Sulaksana PermanaShiva Frida VinciaAnggita AmiliaAhmad MaksumKurnia Setiawan WidanaJohny Wahyuadi Soedarsono2018-10-262018-10-26512 (95)566410.15587/1729-4061.2018.129914Constructing a method for the conversion of numerical data in order to train the deep neural networks
http://journals.uran.ua/eejet/article/view/145586
<p>This paper analyzes known types of deep neural networks, the methods of their supervised training, training the networks to suppress noise, as well as methods for encoding data using images. It has been shown that deep neural networks are suitable in order to effectively solve classification problems, in particular for medical and technical diagnosing. Among the deep networks, the convolutional neural networks are promising because of their simple structure and application of common weights, which makes it possible for a network to separate similar features in different parts of images. Training a convolutional network may prove insufficient for some diagnosing tasks, which is why it is advisable to consider modifications to the training method using data encoding and training to suppress noise in order to obtain a better result.</p><p>We have proposed a method for training a convolutional neural network using numerical data converted to bitmap images, which would improve the accuracy of a network when solving the problems on classification and which would make it possible to apply the convolutional neural networks and their advantages in image processing by using tabular data as input. In addition, the proposed method requires no additional changes to the structure of the network.</p><p>The method consists of four stages – the normalization using a method of min-max, conversion of data into two-dimensional images applying the float or thermometric encoding methods, the generation of additional images with the distortion of input data, and the preliminary training of a deep network.</p>The constructed method was implemented in software and investigated when solving a number of practical tasks. Results of solving the practical tasks on technical and medical diagnosing have shown the effectiveness of the method at small numbers of the resulting classes and training instances. The method could prove useful when diagnosing a defect at the early stages of its manifestation when the volume of training data is limitedMykhailo PryshliakSergey SubbotinAndrii Oliinyk2018-10-252018-10-25512 (95)485410.15587/1729-4061.2018.145586Ray tracing synthesis of images of triangulated surfaces smoothed by the spherical interpolation method
http://journals.uran.ua/eejet/article/view/145531
<span lang="EN-US">The problem of imaging by ray tracing of triangulated surfaces smoothed by the spherical interpolation method was solved. The method of spherical interpolation was mainly designed to interpolate the triangulated surface with the subsequent aim of imaging this surface by the method of ray tracing. This approach makes it possible to combine the method of ray tracing with the accumulated base of models with a triangulated surface. The method of spherical interpolation is universal and enables construction of plane and spatial smooth curves drawn through arbitrarily set points. The proposed interpolation algorithm is based on a simple algebraic surface, sphere, and does not use algebraic polynomials of the third and higher orders. Analytical relations for realization of each stage of construction of an interpolating surface by this method were given. For imaging the interpolating surface, an iterative algorithm (ITA) of calculation of the point of intersection of a projection ray with this surface was constructed. The proposed ITA has an ability of a broad paralleling of computations. An algorithm of constructing points of an interpolating surface was developed with its step coinciding with the step of the iterative computation process which makes it possible to execute the algorithm of imaging and construct the surface point in a single ITA pass. The study results were confirmed by simulation of the imaging process in the Wolfram Mathematica package. Thus, the problem of combining new methods of constructing smooth geometric forms of triangulated surfaces and the method of ray tracing was solved which, in general, will improve realism of synthesized scenes in computer graphics</span>Vladimir GusiatinMaksim GusiatinOleg Mikhal2018-10-252018-10-25512 (95)394710.15587/1729-4061.2018.145531Determining the maximally permissible values for the indicators of insulation of sealed entrance bushings with a voltage of 110 kV using the method of minimal risk
http://journals.uran.ua/eejet/article/view/142185
<p>A method for determining the maximally permissible values for the indicators of insulation of high-voltage oilfilled entrance bushings that ensure the minimal risk value has been proposed. The proposed method differs in that the maximally permissible values for indicators are determined by minimizing the function of average risk, using the Newton’s method, taking into consideration the actual operating conditions of equipment, which makes it possible to improve the operational reliability of entrance bushings.</p><p>We have derived an expression to determine the average risk with respect to the distribution law of indicators for the insulation of high-voltage entrance bushings (by Weibull), the minimization of which makes it possible to determine the maximally permissible values for the indicators, taking into consideration the duration of their operation, the values of load currents, the grade of a transformer oil, and other factors.</p><p>A comparative analysis was performed for risk values, which are accompanied by applying the maximally permissible values for indicators that are regulated in Ukraine, with the maximally permissible values for indicators, which were obtained by using different methods. The analysis revealed that the minimal risk value is ensured by the maximally permissible values for indicators, which are obtained by applying the method of minimal risk, taking into consideration the operating conditions for entrance bushings. We have performed an analysis of impact of the values for probabilities of the proper-functioning and faulty state of entrance bushings, the cost of incorrect decisions, as well as the value for a scale parameter and a shape parameter in the Weibull distribution, on the maximally permissible values for the indicators of insulation of high-voltage oil-filled entrance bushings in an airtight structure. It was established that an increase in the probability of a defect and its conditional cost, as well as prolonging the operation duration of entrance bushings and their loading, leads to a decrease in the maximally permissible values for the indicators. It has been proven that the maximally permissible values for the indicators of insulation of high-voltage entrance bushings, which ensure the minimal economic loss, are not constant. In order to practically implement the method of minimal risk during operation, it has been proposed to apply the likelihood ratios, which make it possible to diagnose the state of high-voltage entrance bushings at a minimal risk, but without determining the maximally permissible values for the indicators.</p>Оleg ShutenkoAlexandra ZagaynovaGalina Serdyukova2018-10-242018-10-24512 (95)61510.15587/1729-4061.2018.142185Studying the efect of nanoliquids on the operational properties of brick building structures
http://journals.uran.ua/eejet/article/view/145246
<p>The study reported here has established that the ceramic facing brick is characterized by capillary porosity that increases indicators of water absorption and capillary pull, as well as efflorescence formation at its surface. In order to protect the surface of such a brick and to provide it with the improved performance properties, we have used hydrophobizing substances. We have determined experimentally that the application of the PMPhS- and AP-based hydrophobizing agents leads to a decrease in porosity by 1.2-1.3 times, in water absorption ‒ by 1.2‒2.3 times, in water absorption at capillary pull ‒ by 1.1‒3.2 times. Research into frost resistance has found that for the ceramic brick, covered with PMPhS, it increases by 15 cycles, and when treating a brick surface with AP ‒ by 20 cycles, compared to the untreated brick (F50). By employing an electron microscopy, it was determined that the alternating freeze-thawing leads to that the brick's surface, treated with PMPhS and AP, demonstrates the formation of microcracks (in this case, water absorption increased by 42 and 28 %). By applying a method of mathematical planning of the experiment, it was found that the most effective hydrophobizing substance is the modifier that contains the nano-Al<sub>2</sub>O<sub>3</sub> powder (a nano-liquid). It was determined that when treating the surface with a nano-liquid (the amount of nanо-Al<sub>2</sub>O<sub>3</sub> is 0.8 %), its water absorption decreases to 1.2‒1.6 %, its water absorption indicator at capillary pull ‒ to 0.08‒0.12 kg/m<sup>2</sup>∙h<sup>0.5</sup>. Using a method of defectoscopy, applying the Karsten tube, it was found that water absorption for the brick whose surface was coated with a nano-liquid reduced from 0.15 to 0.002 ml/cm<sup>2</sup>, indicating a high level of hydrophobization. The electron microscopy method confirmed that the modification of the ceramic brick surface by the hydrophobizing nano-fluids makes it possible to compact the structure through the colmatation of pores and microcracks, which reduces the capillary pull of the brickwork. That also leads to the improved atmospheric and frost resistance of brick building structures.</p>Thus, there is a reason to argue about the possibility of improving the physical and technical indicators of the brick building structure by modifying the surface of the ceramic facing brick by a nano-fluidTetiana KropyvnytskaRoksolana SemenivRoman KotivAndriy KaminskyyVladyslav Hots2018-10-222018-10-22512 (95)273210.15587/1729-4061.2018.145246Construction of a mathematical model of extraction process in the system "solid body ‒ liquid" in a microwave field
http://journals.uran.ua/eejet/article/view/145232
<p>We have analyzed the extraction process in the technology of oilseed processing. This paper describes the original provisions, specificity, modern scientific schools, and the level of representation of the classic extraction process. The specificity of mathematical modeling of the extraction process, given the introduction of an additional driving force that significantly affects the kinetics of extraction in an electromagnetic field of ultra-high frequency, is considered from the classical theory of the process.</p><p>We have constructed the extraction kinetics calculation formulae, in microwave field, which develop the theory of extraction kinetics in an electromagnetic field. The paper gives an analysis of variants for the representation of a mathematical notation of the extraction process of disperse materials in an electromagnetic field of ultra-high frequency. A complete model of the mass exchange processes during extraction in a microwave field in the differential form will make it possible to generate conditions for conducting comprehensive experimental studies, which would fully define the extraction process of oilseeds.</p><p>We have theoretically substantiated the process of heat and mass exchange between the all defining objects inside an extraction unit with an electromagnetic field of ultra-high frequency. Based on material balances, we derived equations describing the basic dynamic characteristics of oil extraction mode in an extraction unit. Since the precise analytical solution to the presented mathematical model in the form of a system of differential equations in particular derivatives does not exist, the approximate solution has been proposed. It makes it possible to identify the distribution of an extractant depending on the size of fractions of raw materials, the existence and magnitude of power of the pulsed electromagnetic field of ultra-high frequency, the extractant's hydro-module, temperature, solvents, for any point in time.</p>Based on the experimental research into extraction of oilseed material, it was established that under the action of microwave radiation a value for the mass release coefficient during extraction of oilseed raw materials grows by an order of magnitude (β=1·10<sup>-5</sup>) compared to extraction without the effect of MW field (β=1·10<sup>-6</sup>). Oil extraction under the action of a microwave field increases to 30 %, while electricity consumption decreases by 93‒97 %. The application of a microwave field would not only improve production efficiency, but reduce energy costs during process by an order of magnitudeBoris KotovValentina Bandura2018-10-222018-10-22512 (95)334310.15587/1729-4061.2018.145232A study of the effect of tungstate ions on the electrochromic properties of Ni(OH)2 films
http://journals.uran.ua/eejet/article/view/145223
<p class="1">Thin films of nickel hydroxide were prepared using the cathodic template method and were tested in different electrolytes. The electrolytes were 0.1 M KOH and 0.1 M KOH with the addition of 0.1, 0.3 and 1 mM K<sub>2</sub>WO<sub>4</sub>. The test revealed<span style="text-decoration: line-through;">,</span> that the presence of tungstate can have a significant effect on electrochemical and electrochromic characteristics of Ni(OH)<sub>2</sub> films. The initial sample, cycled in 0.1 M KOH showed different characteristics from those cycled in tungstate-containing electrolytes: significant difference between current densities of cathodic and anodic peaks and presence of the current plateau on the cyclic voltamperometry curve. However, the initial sample demonstrated the highest coloration degree of 74 %. On the other hand, the sample showed degradation of the coloration degree past initial growth.</p><p class="1">The samples cycled in the tungstate-containing electrolyte showed better electrochemical characteristics – sharper cathodic and anodic peaks, with the lesser difference between peak values. The dynamics of the absolute coloration degree of the samples cycled in tungstate-containing electrolyte showed a constant increase. The sample tested in a solution with 1 mM tungstate had the lowest value of the absolute coloration degree – 60 %. For tungstate concentrations of 0.1 and 0.3 mM, the absolution coloration degree at the last cycle was 72 and 71 % respectively.</p><p class="1">The samples tested in a solution with tungstate additive had a significantly lower bleaching time – 40–50 s in comparison to 360 s of the sample cycled in 0.1 М KOH.</p>A possible mechanism that explains such differences in behavior was proposedValerii KotokVadym Kovalenko2018-10-222018-10-22512 (95)182410.15587/1729-4061.2018.145223Studying the photocatalytic oxidation of hydroxybenzene in aquatic medium on the photocatalizers SnO2, ZnO, TiO2
http://journals.uran.ua/eejet/article/view/145198
This paper reports results of research into photocatalytic activity of oxides SnO<sub>2</sub>, ZnO, TiO<sub>2 </sub>in the process of hydroxybenzene degradation in an aqueous medium with the separately considered properties of the allotrope modifications of titanium oxide (IV): anatase and rutile. The relationship has been substantiated between a decrease in the value for the width of the restricted area and an increase in the photocatalytic activity of the examined oxides. The effect has been established of the organization of agitation on an increase in the degree of hydroxybenzene degradation in an aqueous medium, which is 10‒15 % on average. We have studied the influence of ratio of anatase to rutile in a photocatalyst on the hydroxybenzene degradation efficiency. It has been shown that the results obtained in the course of the study are consistent with data from the scientific literature, while opening up additional possibilities to increase the degree of hydroxybenzene oxidation in a joint application of anatase and rutile. It was established that the greatest degree of oxidation with and without agitation at an irradiation time of 60 minutes can be achieved at the content ratio of anatase to rutile of 75/25 % and is 23 % and 37 %, respectively. The use of such a composition makes it possible to increase the degree of hydroxybenzene oxidation in an aqueous medium by 11‒18 %, which is 1.5‒1.9 times larger in comparison with pure rutile and anatase. The results obtained led to the conclusion on that in order to reduce the time required to achieve the maximal indicators for the process of hydroxybenzene degradation, it is necessary to increase the ratio of the irradiated surface to the height of the device and to increase the Re number of the agitation process. Based on the obtained experimental data, we have established the optimum composition of a photocatalyst, which makes it possible to reach the maximal degree of hydroxybenzene recovery from solutionDmytro DeinekaOleksandr KobzievSvitlana AvinaSvitlana GrinViktoriya DeynekaDmytro TaradudaVitaliy Sobina2018-10-222018-10-22512 (95)596710.15587/1729-4061.2018.145198Improvement of safety of autonomous electrical installations by implementing a method for calculating the electrolytic grounding electrodes parameters
http://journals.uran.ua/eejet/article/view/144925
We have solved the task of safety improvement in the grounding process of autonomous mobile electrical installations. Existing procedures for the calculation of normalized resistance of grounding electrodes in electric installations have been examined and studied. Their main drawbacks have been revealed: the difficulty and complexity of calculations; the probabilistic and approximate character; the use of source data taken to calculate the electrophysical parameters of stationary grounding electrodes; the calculations do not account for the structural-phase structure of soil and the volume of electrolyte. Based on the application of percolation theory and the apparatus of fractal-cluster geometry, we have modeled the process of electrolytic grounding in heterogeneous soils of different porous structure, which possess the percolation and fractal properties. A physical model of the process of electrolytic grounding has been developed, which takes into consideration the soil structure properties when changing the fractal dimensionality of a cluster over a certain range that forms the electrolytic grounding conductor with the normalized resistance. It has been shown that the model of conductivity of the electrolytic grounding electrode is defined by the soil electrical conductivity in a percolation channel of the porous structure of soil and can be considered as a function of the volumetric concentration of the electrolyte and the size of the volumetric structure of the electrolytic percolation cluster. We have derived analytical expressions to relate the normalized resistance of electrolytic grounding conductors and the specific resistivity of soil to the fractal dimensionality, volume of the electrolyte, the number of pores to the electrolyte, density of a geometrical volumetric body. We have improved a method for calculating the electrophysical parameters of electrolytic grounding conductors, based on accounting for the main linear size of the cluster of an electrolytic volumetric body, which coincides with the electrolyte penetration depth for various soil structures. We have established conditions for conductivity of the electrolytic grounding conductor in order to ensure safety during operation of the autonomous mobile electrical installationPavlo BudanovKostiantyn BrovkoArtem CherniukIryna PantielieievaYuliya OliynykNataliia ShmatkoPavlo Vasyuchenko2018-10-192018-10-19512 (95)202810.15587/1729-4061.2018.144925Improvement of a discharge nozzle damping attachment to suppress fires of class D
http://journals.uran.ua/eejet/article/view/144874
<p>The software package COSMOSFloWorks has been used to study a discharge nozzle damping attachment. A procedure has been proposed to estimate the covering of surface with dimensions of 0.4×0.4 m by a fire-extinguishing powder. It was established that existing discharge nozzle damping attachments are not efficient because at extinguishing light metals they do not effectively reduce the speed of powder supply onto a flammable surface and fan the fire, not being able to cover the burning surface by a fire-extinguishing powder. After putting out the fire the surface that was covered with powder reveals the burnouts. We have modeled the optimal structural parameters for a discharge nozzle damping attachment in order to extinguish fires of class D in the form of a discharge nozzle damping attachment with an elliptical top and a parabolic reflector. It has been proven that a damping attachment with two working surfaces outperforms the previous damping attachment with a single working surface by 30 %. Given this, the fire-extinguishing powder covers the burning surface by a larger layer, preventing the fanning of chips from the surface of a burning metal, thereby shortening the duration of burning and improving the efficiency of a fire-extinguishing powder supply. Experimental study has confirmed that the use of a damping attachment that supplies a fire-extinguishing powder with two working surfaces in order to extinguish fires of class D increases the powder feed to a fire site, reaching above 90 %.</p><p>The diameter and the shape of the attachment have been determined. The attachment must acquire the form of a diffuser with a diameter of 16 mm.</p>Our development could be used when designing the stationary and portable fire extinguishing systems for light metals and alloys, including incendiary grenades under condition of proper selection of the powder. We have achieved positive results during field tests of the discharge nozzle damping attachment using a make-up fire to burn the shavings of magnesium alloysVasyl KovalyshynVolodymyr MarychYaroslav NovitskyiBogdan GusarVolodymyr ChernetskiyOlexandr-Zenoviy Mirus2018-10-192018-10-19512 (95)687610.15587/1729-4061.2018.144874