Journal of Engineering Sciences / Журнал інженерних наук
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Item Effect of sodium chloride on corrosion inhibition efficiency of polyethylene coatings on alloy steel at ambient temperature(Sumy State University, 2020) Anyanwu, K.O.; Ogu, I.S.; Nzei, H.O.An investigation was conducted on the effect of sodium chloride concentration on corrosion inhibition efficiency of High-Density Polyethylene (HDP) coating on alloy steel in sodium chloride solutions of different degrees of salinity. In the study, four test media were used: the first is 20 l of distilled water in a rectangular base plastic container; the second is 20 l of distilled water in a rectangular base plastic container in which 200 g of sodium chloride (NaCl) was dissolved entirely, giving a concentration of 10 g/l (0.01 g/cm²). Similarly, the third medium is 20litres of distilled water in which 300 g of NaCl was dissolved entirely, having 15 g/l (0.015 g/cm²) concentration. The fourth medium is prepared by dissolving 400 g of NaCl in 20litres of distilled water, resulting in 20 g/l (0.02 g/cm²) concentration. The container used for each medium is a rectangular base plastic container. Twenty-eight (28) uncoated and twenty-eight (28) polyethylene-coated alloy steel coupons of dimension 5×30×50 mm with an 8 mm diameter hole each were used for this investigation. Seven coated coupons each were wholly immersed in 10, 15, and 20 g/l, and zero salinity distilled water. Similarly, seven uncoated coupons each were immersed entirely in 10, 15, and 20 g/l and zero salinity distilled water. The coupons in various test media were exposed to ambient temperature for a total of 49 days. One coupon from each of the media is reweighed on weekly bases and the weight loss (g), corrosion rate (mm/year), and corrosion inhibition efficiency were calculated and recorded. From the results obtained, the corrosion rate of the coupons increases with an increase in sodium chloride solution. It is also observed from the results obtained considering the variation of corrosion rates of polyethylene coated coupons with sodium chloride concentration and the variation of corrosion rates of uncoated coupons with sodium chloride concentration that the corrosion rate of the coupons is lesser with the polyethylene coating compared with the uncoated coupons. The results show that the corrosion rate of coupons falls over time, and more rapidly at an early time of exposure, say the first week. From the result of the variation of corrosion inhibition efficiencies of polyethylene coated coupons with sodium chloride concentration, it is observed that the corrosion inhibition efficiency of polyethylene decreases over time and decrease also with an increase in sodium chloride concentration.Item Аn experimental study of heat and mass transfer in a falling liquid film evaporation into a cross flow of a neutral gas(Sumy State University, 2020) Лукашов, Володимир Костянтинович; Лукашов, Владимир Константинович; Lukashov, Volodymyr Kostiantynovych; Kostiuchenko, Y.V.; Timofeev, S.V.; Ochowiak, M.The work is devoted to the study of heat and mass transfer in a liquid film flowing down on a heated surface under conditions of evaporation into a crossflow of a gas neutral with respect to the liquid. The work aimed to experimentally determine the average heat transfer coefficients from a heated surface to the film, heat transfer and mass transfer from the film to the gas flow and to establish their dependence on the input parameters of the heat and mass transfer process. To achieve this goal, an experimental setup was created, and a research technique was developed based on the proposed mathematical model of the heat and mass transfer process. The results of the study showed that the dependences of the average heat and mass transfer coefficients on the initial liquid flow rate are extreme with the minimum values of these coefficients at the liquid flow rate, which corresponds to the critical value of the Reynolds criterion Re l cr ≈ 500, which indicates a transition from the laminar falling films to turbulent mode under the considered conditions. The dependences of the heat and mass transfer coefficients on other process parameters for both modes of film falling are established. A generalization of the experimental data made it possible to obtain empirical equations for calculating these coefficients.Item Heliosystem of Auxiliary Heat Supply for a Mining Enterprise(Sumy State University, 2020) Shkrylova, S.; Kostenko, V.; Skrynetska, I.In the conditions of the global ecological crisis in the world and Ukraine, the issue of finding alternative energy sources becomes relevant. One of the most common types of renewable energy is solar energy. In Ukraine today, the most promising direction of using solar energy is its direct transformation into low-potential thermal energy. To get electric power, solar radiation is the mere alternative to electric power generated from mined fuel, and without the pollution of air and water, or adverse consequences manifested in global warming. The disadvantage of this type of installation is the limitation of the duration of light time, as well as the effect of cloudiness. During the day, the number of solar radiation changes, to stabilize it is necessary to accumulate and accumulate it for further use, the technical implementation of stable operation of solar installation due to the use of terrestrial radiation and the accumulator of a specific part of solar energy is proposed. The purpose of the work is experimental studies to ensure the stable operation of the solar collector under cloudy conditions. The paper is aimed at the stabilization of the operation of the solar installation and to obtain additional heat after the Sun’s cloud cover. The use of a solar thermal collector is advisable in solar heating and hot water systems in conditions of alternating solar radiation. The results of physical modeling have proved the efficiency of the method of combining types of thermal radiation, due to the accumulation of energy it is possible to increase the quantitative index of solar energy in the conditions of cloudiness by 3 times.Item Ontological tools in anaerobic fermentation technologies: Bioinformation database applications(Sumy State University, 2020) Shulipa, Ye.O.; Черниш, Єлізавета Юріївна; Черныш, Елизавета Юрьевна; Chernysh, Yelyzaveta Yuriivna; Пляцук, Леонід Дмитрович; Пляцук, Леонид Дмитриевич; Pliatsuk, Leonid Dmytrovych; Fukui, M.An important direction of forming an effective system for recycling waste of various genesis is to optimize the processes of their treatment using the latest information resources. The paper deals with theoretical studies of directions for the systematization and optimization of anaerobic waste processing technologies using ontological tools based on information resources. Significant scientific support to biochemical research is provided by electronic bioinformatics databases such as KEGG, BacDive, and EAWAG-BBD, etc., which provide access to a collection of graphical representations and text descriptions of metabolic or signal pathways, schemes of regulation of biological processes, information about the organism. They cover various aspects of bacterial and archaic biodiversity, information on microbial biocatalytic reactions and biodegradation pathways of mainly xenobiotic chemical compounds. Also, in the course of work based on analytical data of electronic databases of bioinformatics, in particular, the interaction of necessary ecological and trophic groups of microorganisms, biochemical simulation of anaerobic waste processing with biofuel production was carried out.Item Thermal-Hydraulic Performance of Graphene Nanoribbon and Silicon Carbide Nanoparticles in the Multi-Louvered Radiator for Cooling Diesel Engine(Sumy State University, 2020) Nogueira, E.Analytical solution for application and comparison of Graphene Nanoribbon and Silicon Carbide for thermal and hydraulic performance in flat tube Multi-Louvered Finned Radiator is presented. The base fluid is composed of pure water and ethylene glycol at a 50% volume fraction. The results were obtained for Nusselt number, convection heat transfer coefficient and pressure drop, for airflow in the radiator core and nanofluids in flat tubes. The main thermal and hydraulic parameters used are the Reynolds number, the mass flow rate, the Colburn Factor, and Friction Factor. In some situations, under analysis, the volume fraction, for Graphene Nanoribbon and Silicon Carbide, were varied. The value of the heat transfer coefficient obtained for Graphene Nanoribbon, for the volume fraction equal 0.05, is higher than twice the amount received by Silicon Carbide. The flow is laminar, for whatever the fraction value by volume of the Graphene nanoparticles when the mass flow of the nanofluid is relatively low. For turbulent flow and relatively small fractions of nanoparticles, the heat transfer coefficient is significantly high for mass flow rates of Graphene Nanoribbon. The pressure drop, for the same volume fraction of nanoparticles, is slightly higher than the pressure drop associated with Silicon Carbide. These high values for the heat transfer coefficient is a favorable result and of great practical importance, since lower values for the fraction in volume can reduce the costs of the compact heat exchanger (radiator).Item Environmental monitoring smart system with selfsustaining wireless sensor network using data validation algorithms(Sumy State University, 2020) Kanwal, T.; Altaf, S.; Javed, M.K.Study in Wireless Sensor Network (WSN) has been becoming an emerging and promising research topic aiming for the advancement in the Internet of Things (IoT) for a reliable connection. The capability of the wireless sensor to be used in a complex environment can become hard to reach areas and also be able to communicate in an ad-hoc manner, attracted researchers in recent times. Development in wireless sensor network producing a lot of new applications to sense environment remotely are facing challenges restricting it to perform up to its potential. Data validation and data reliability are such existing problems in this domain that needed to be addressed. Because sensed data cannot be blindly trusted upon, as it may have faults and errors occurred with-in the sensing environment. Besides, to guarantee the active state of the sensing system in a remote area is also essential in terms of power usage and management. The focus of the paper is data validation acquired from sensors deployed in remote areas. Although, lots of data validation algorithms have been proposed by researchers to identify single data fault. However, our research identifies multiple faults, namely spike fault, out of range fault, outliers, and stuck at fault using a hybrid form of an algorithm. A comparison with the existing algorithm shows that the proposed algorithm improved data validation by 97 % in detecting multiple data faults using Artificial Intelligence techniques.Item Thermodynamic and Economic Evaluation of Gas Turbine Power Plants(Sumy State University, 2020) Oyegoke, T.; Akanji, O.I.; Ajayi, O.O.; Obajulu, E.A.; Abemi, A.O.Thermodynamic analysis and economic feasibility of a gas turbine power plant using a theoretical approach are studied here. The operating conditions of Afam Gas Power Plant, Nigeria are utilized. A modern gas turbine power plant is composed of three key components which are the compressor, combustion chamber, and turbine. The plants were analyzed in different control volumes, and plant performance was estimated by component-wise modeling. Mass and energy conservation laws were applied to each component, and a complete energy balance conducted for each component. The lost energy was calculated for each control volume, and cumulative performance indices such as thermal efficiency and power output were also calculated. The profitability of the proposed project was analyzed using the Return on Investment (ROI), Net Present Worth (NPW), Payback Period (PBP), and Internal Rate of Return (IRR). First law analysis reveals that 0.9 % of the energy supplied to the compressor was lost while 99.1 % was adequately utilized. 7.0 % energy was generated within the Combustion Chamber as a result of the combustion reaction, while 33.2 % of the energy input to the Gas Turbine was lost, and 66.8 % was adequately converted to shaft work which drives both compressor and electric generator. Second law analysis shows that the combustion chamber unit recorded lost work of 248.27 MW (56.1 % of the summation), and 77.33 MW (17.5 % of the summation) for Gas Turbine, while air compressor recorded 11.8 MW (2.7 %). Profitability analysis shows that the investment criteria are sensitive to change in the price of natural gas. Selling electricity at the current price set by the Nigerian Electricity Regulation Commission (NERC) at zero subsidies and an exchange rate of 365 NGN/kWh is not profitable, as the analysis of the investment gave an infinite payback period. The investment becomes profitable only at a 45 % subsidy regime.Item Vibrational impact on milled surface irregularities(Sumy State University, 2020) Lishchenko, N.V.; Larshin, V.P.; Pitel, J.The methodology and results of a simultaneous study of causally linked parameters of mechanical vibration (cause) and surface irregularities (consequence) in flat milling with an end mill are given. The features of measurement and analysis of surface quality parameters through the application of the separation frequency method of profilogram harmonic components on the surface roughness, waviness, and the deviation of the profile are reviewed. A new method of profilogram digital processing is developed, comprising the steps of its digitization, lowpass filtering, and the formation of the roughness profile. The initial theoretical positions on modeling mechanical (elastic) waves which are caused by vibration in the cutting zone and propagate in a solid, liquid, and gas (air) media are presented. The results of experimental studies of milled surface profilogram and the vibro-displacement signal in the milling are given.Item An algorithm for the detection of circular elements in engineering design(Sumy State University, 2020) Bonello, D.K.; Iano, Y.; Neto, U.B.Various concentrated works have been done in the area of computational vision regarding the circle and texture detections. Detection of circles in images can be beneficial for PCB components industries for the detection of capacitors in printed circuit boards, also for medicine in the detection of red cells, white blood cells, and leukocytes, and for applications which requires precision and assignments regarding the detection of circles in a digital image. In this work is utilized a benchmarking of images to detection circle boards of different radio values for the comparison with the work [1] of this article. The benchmarking of images is composed of five main images that are tested in the algorithm of detection of circles in MATLAB with different values of radio for each image. The results appoint an enhancement of 300 % concerning the algorithm proposed in work [1] showed in this article. In this work also would be plotted graphs concerning the accuracy of the new proposed algorithm with relation to the algorithm proposed in work [1], indicating better results concerning the GUI interfaces and capacity of detection circles.Item Modern trends in the mathematical simulation of pressure-driven membrane processes(Sumy State University, 2020) Huliienko, S.V.; Korniienko, Y.M.; Gatilov, K.O.The presented article is an attempt to evaluate the progress in the development of the mathematical simulation of the pressure-driven membrane processes. It was considered more than 170 articles devoted to the simulation of reverse osmosis, nanofiltration, ultrafiltration, and microfiltration and the others published between 2000 and 2010 years. Besides the conventional approaches, which include the irreversible thermodynamics, diffusion and pore flow (and models which consider the membrane surface charge for nanofiltration process), the application of the methods the computational fluid dynamics, artificial neural networks, optimization, and economic analysis have been considered. The main trends in this field have been pointed out, and the areas of using approaches under consideration have been determined. The technological problems which have been solved using the mentioned approaches have also been considered. Although the question of the concentration polarization has not been considered separately, it was defined that, in many cases, the sufficiently accurate model cannot be designed without considering this phenomenon. The findings allow evaluating more thoroughly the development of the simulation of pressure-driven membrane processes. Moreover, the review allows choosing the strategy of the simulation of the considered processes.