Journal of Engineering Sciences / Журнал інженерних наук
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Item Controlled synthesis of TiB2-TiC composite: Substantiation of the homogenizing Joule thermostatting efficiency and improvement of SHS-compaction technology in a vacuum(Sumy State University, 2024) Jandieri, G.; Sakhvadze, D.This research aims to improve and substantiate the efficiency of homogenization heat-stabilizing Joule heating on ceramic-matrix composites of TiB2-TiC system with a 2:1 component ratio during its synthesis. For this purpose, an improved technological approach is proposed, which is based on the known method of SHS-compacting but differs by the possibility of controlled Joule influence on the synthesis products, which is achieved by the use of a special electrothermal vacuum press-mold functioning according to a particular control algorithm. The task of controlled Joule heating is a compensation of the temperature gradient formed in the synthesized workpiece, which is solved by passing in it a direct current directed in line with the vector of propagation of the combustion wave. An indicator of assessment of the degree of compensation of the noted temperature gradient is the Seebeck effect, excited between the upper and lower surface of the SHS workpiece, which should be brought to zero in the process of Joule thermostatting. It was experimentally revealed that compensation of the noted temperature gradient with heat released predominantly by electrically conductive and Joule-heated TiC grains leads to their softening, which contributes to more uniform compaction of the workpiece due to diffusion coalescence of these grains around prism-shaped hard TiB2 crystals. Such consolidation leads to a significant increase in the quality of structural packaging and a reduction in the number and volume of micropores, as a result of which the performance properties of the composite improve on average by 10–15 %.Item Kinematic analysis of 3-PRPPS spatial parallel manipulator with circularly guided base for singularity-free robotic motions(Sumy State University, 2024) Shaik, H.S.Robot manipulators are classified as serial manipulators and parallel manipulators. Parallel manipulators are classified into planar and spatial parallel manipulators (SPMs). The parallel manipulators have moved and fixed platforms connected with serial chains. The parallel manipulators have many linkages, which create a singularity problem. The singular positions of SPMs have also gained substantial attention in various industrial applications due to their intrinsic advantages in precision, flexibility, and load-bearing capabilities. The 3-PRPPS SPM has three prismatic joints, one spherical joint, and one revolute joint. This work changed the fixed base with a circular guided base to avoid singularity issues. The manipulator was modeled with direct kinematic relations. The Jacobian matrix for position and orientation was derived. The workspace was taken as the common area of the three circles, whose radius was the maximum arm length. The position and orientation of the end effector were traced. In the form of the end effector traces, no singularities in the mechanism were observed. The path of the robot manipulator was observed in all the possible positions and orientations. The multi-body simulation was also conducted on the 3-PRPPS manipulator, the main findings of which are presented in this article.Item Efficiency Investigation of Coffee Production Waste Drying by Filtration Method(Sumy State University, 2024) Ivashchuk, O.S.; Atamanyuk, V.M.; Chyzhovych, R.A.This article presents the results of determining the technologically feasible parameters of filtration drying of coffee production waste based on experimental data on the kinetics of material drying and the hydrodynamics of thermal agent filtration. The lowest total energy costs were observed with the following process parameters: the material layer height of 120 mm, the thermal agent temperature of 90 °C, the velocity through the stationary layer of 1.76 m/s, and the specific energy consumption of 5857 kJ per 1 kg of water. Based on the determined technologically feasible process parameters, an evaluation of the filtration drying method for coffee production waste was performed at an industrial installation. According to the calculation, using the filtration method, 1164 kW h of energy was required to dry about 1000 kg of coffee production waste. A total energy of about 1.65 kW h/kg was required to remove 1 kg of moisture from the material in an industrial filtration drying installation. The results were compared with a drying material with similar initial parameters. It was calculated that to dry 1000 kg of coffee production waste in a rotary dryer, it is necessary to spend about 1625 kW h, and the total energy consumption for removing 1 kg moisture from the studied material is approximately 2.37 kW h/kg. Thus, for a similar output of about 1000 kg/h, filtration drying can reduce energy consumption by about 465 kW·h and reduce the required drying time by more than 20 times. The overall economic effect of using the filtration drying method in industry is expected to be higher, given the significant heat losses to the environment for a rotary dryer due to its large size, long drying time, design features, and the need for energy-intensive auxiliary equipment. After calculating the energy consumption per 1 kg of dry material, it is necessary to spend 12 950 kJ/kg of dry matter, about 41.5 % less than the higher calorific value for experimental samples of briquetted solid fuel made from this material. This result makes it economically feasible to further dry coffee production waste to produce alternative solid fuels.Item Optimal Layout of the Head Drive for a Self-Supporting Bucket Elevator of High Productivity(Sumy State University, 2024) Kurhan, V.; Sydorenko, I.; Kurgan, V.; Dudko, R.; Bershak, S.The article deals with bucket elevators of high productivity. The demand for grain crops is growing worldwide, requiring transportation, transshipment, and storage in huge volumes. Based on this, it is urgent to solve the problem of increasing the productivity of bucket elevators in the self-supporting version. The problem is that increasing performance requires increasing the drive’s power, leading to a significant weight increase. This imposes a limit on the height of the bucket elevator. A considerable weight at a high altitude significantly reduces the stability of the structure itself. For the most part, this problem was solved by limiting the height or productivity of the bucket elevator. The construction of a self-supporting bucket elevator, possible layouts of the head drive, and advantages and disadvantages were considered. Three bucket elevators with different heights, productivity, and belt width were selected to determine the optimal layout. Four drive options were calculated for each design, and a comparative analysis was carried out using a graphical method. The analysis showed that one of the biggest problems is the displacement of the center of mass relative to the central plane of the bucket elevator. As a result, means to ensure the smallest displacement coefficient relative to the vertical axis of the bucket elevator were presented. Advantages, disadvantages, and the possibility of constructive implementation of the layouts were also considered.Item Improvement of the ecological efficiency of synthetic motor fuel production in Ukraine(Sumy State University, 2024) Shulga, I.; Kyzym, M.; Kotliarov, Y.; Khaustova, V.Solving the problem of improving energy security is one of Ukraine’s challenges in modern conditions. One of the ways to solve this problem is to organize the production of synthetic motor fuel from the available domestic carbon-containing raw materials. The relevance of developing the production of synthetic motor fuel in Ukraine from non-oil raw materials is associated with the shortage of deposits of traditional crude hydrocarbon and the destruction of the last processing capacities due to russian aggression. The article aims to substantiate the possibility of efficiently producing synthetic motor fuels from the available mineral hydrocarbon raw materials. Analyzing the existing deposits of hydrocarbons allowed for determining low-metamorphosed coal as the most expedient raw material base. A comparative analysis of various technologies made it possible to suggest the organization of the production of synthetic motor fuel through indirect hydrogenation, followed by fuel synthesis in the Fischer–Tropsch process. Calculations performed for low-metamorphosed Ukrainian coal showed the technical and environmental efficiency of the hydrogen enrichment of synthesis gas. To enrich synthesis gas with hydrogen, it was proposed to cooperate with producing synthetic motor fuel with coal mines (suppliers of raw materials, including methane for the production of additional hydrogen) or coke ovens and by-product enterprises that produce hydrogen-rich coke oven gas.Item Optimization of technological parameters for cold spraying using the response surface method(Sumy State University, 2024) Hu, W.J.; Shorinov, O.Cold spray technology can obtain coatings in a solid state, which is suitable for deposition protective and restorative coatings. Currently, most of the research in cold spraying is based on a single-factor analysis to explore the law. However, the interaction effect of multiple factors is more scientific. In this study, the response surface method (RSM) was used to optimize the technological parameters of cold spraying. A multi-factor and multi-level quadratic regression model was established for gas temperature, pressure, and particle diameter of outlet velocity, and the process parameters were optimized. The results showed that the gas temperature, particle diameter, and gas pressure have significant effects under a single factor. Also, under the interaction of multiple factors, the P-value of the quadratic regression model was less than 1·10–4 , and the R2 of the model was 0.9626, indicating that the curve fitting is good and the model has good credibility. The interaction between gas pressure and gas temperature is significant, while the interaction between gas temperature and powder diameter, gas pressure, and powder diameter are insignificant. Moreover, the parameter error between the optimized parameters through response surface analysis and the actual numerical simulation is 0.76 %, indicating high accuracy.Item Mechanical properties and stress analysis of natural fiber reinforced polymer composite spur gear(Sumy State University, 2024) Jayaraj, M.; Ashok, S.K.; Thirumurugan, R.; Shanmugam, D.; Mahendran, M.This research study investigates the mechanical properties of polymer composites reinforced with natural fibers, specifically Palmyra palm leaf stalk fiber (PPLSF) and Palmyra palm primary leaf stalk fiber (PPFLSF). Tensile, flexural, and impact strength were among the composites’ mechanical parameters generated by integrating these fibers into a polymer matrix and assessing them experimentally. Additionally, stress analysis of a spur gear was conducted using the finite element analysis software ABAQUS. The composite material properties obtained from the experimental investigation were used in the analysis to evaluate the gear’s stress distribution and deformation behavior. The bending stress at the pitch point of the natural composite gears for PPLSF, PPFLSF, and nylon synthetic material is analyzed using analytical and experimental methods by ABAQUS software. Finally, the results are compared with each other. The results show that stress induced by nylon is comparatively higher than that of PPLSF and PPFLSF fiber. By analyzing these composites’ strength, durability, and stress distribution under operating environments, the study aims to determine whether they are suitable substitutes for conventional materials.Item Multi-performance optimization of the mechanical characteristics of basalt fiber and silicon carbide-filled aluminum matrix composites(Sumy State University, 2024) Veeranaath, V.; Dinesh, S.G.; Natarajan, G.In the existing state, aluminum metal matrix composites (AlMMCs) are a category of materials that have successfully fulfilled the majority of demanding requirements in applications where moderate strength, high stiffness, and lightweight are necessary. This paper is focused on processing aluminum hybrid composites by reinforcing the aluminum alloy with a novel combination of fillers: basalt fibers and silicon carbide via stir casting. The main aim is to study the impact of processing conditions on the properties of the developed composite. Nine samples are produced by varying the reinforcement content, stirring rate, and duration based on the L9 Taguchi Array. SEM analysis is utilized to examine the microstructure of the developed composites. The samples were also machined and tested for their mechanical, physical, and wear behavior as per ASTM standards. The maximum density and hardness of 2883.3 kg/m3 and 45.6 HRB, respectively, are observed at higher filler content conditions. In contrast, the minimum specific wear rate, maximum ultimate tensile, and impact strength of 1.86·10–5 mm3 /(N·m), 263.5 MPa, and 93 N/mm are observed in higher stirring duration conditions. So, to avoid conflicting combinations of optimal input factors, grey relational analysis (GRA) tied with principle component analysis (PCA) is employed to determine the multi-objective performance parameter and the optimal combination of input factors for better response. Confirmatory tests were also performed to verify and validate the same. ANOVA analysis is also utilized to assess the significance of the process parameters on the responses.Item Simultaneous optimization of delamination and thrust force during drilling of GFRP laminate with a core drill by E-PIV method(Sumy State University, 2024) Babu, J.; Ramana, M.V.; Vivek, D.; Reddy, C.H.S.Aeronautical applications are permanently improving because of the excellent mechanical capabilities of glass-fiber-reinforced polymers (GFRP). Drilling is a vital machining task required to put the structures made of these composites together. However, these GFRP composites need more precise machining than metallic materials. This machining procedure causes delamination in the composite composition. Delamination at the exit and entry of drilled holes is a severe problem for composite materials. By maximizing the controlling variables of the drilling process, superior-drilled holes can be generated. The present study aims to optimize the drilling settings by considering various performance aspects using the entropy weight-coupled proximity indexed value method. For this study, Taguchi’s L25 5-level orthogonal array was employed. The responses are at the exit, entry delamination, and thrust force, while the control variables are feed rate and spindle speed. The findings indicate that more significant spindle speeds and smaller feed rates improve drilling success. Furthermore, current research indicates that feed rate has a more significant impact on the quality of the drilling holes.Item Adsorptive removal of lead (II) pollutants from wastewater using corncob-activated carbon(Sumy State University, 2024) Aliyu, S.A.; Salahudeen, N.; Rasheed, A.A.The level of contamination in industrial wastewater has been a serious environmental challenge of our time. Various researchers have reported that the adsorption process using different adsorbents is a promising technique for treating heavy metal-contaminated wastewater. This study investigated the adsorptive removal of lead (II) from wastewater using corncob-activated carbon. Activated carbon was synthesized from a raw corncob. The synthesized activated carbon was applied as a sorbent in batch lead (II) adsorption in an aqueous lead (II) solution. Scanning electron microscopy, Fourier transformed infrared (FTIR), and Brunauer–Emmett–Teller (BET) theory characterized the synthesized activated carbon. A batch adsorption study investigated the effects of dosage, contact time, and the initial concentration of lead (II) on the sorption of Pb2+ on the synthesized activated carbon. The highest removal of lead recorded was 95 % at an adsorbent dosage of 2.5 g/L in 2 h. The highest adsorption capacity was 16.46 mg/g at the same conditions. The results showed that percentage removal increased with dosage and contact time but decreased with the initial metal ion concentration. Adsorption kinetics were best described with the pseudo-second-order kinetics, while the Langmuir isotherm model best fitted equilibrium adsorption in the study. The FTIR results showed the presence of several functional groups like carboxyl, hydroxyl, and amino, indicating good interaction with lead metal ions. The BET characterization revealed the activated corncob’s specific surface area and pore volume to be 249 m2 /g and 0.164 cm3 /g. This work shows that activated carbon can be synthesized from agricultural waste such as corncob and be used as an effective adsorbent for heavy metal removal, such as lead, from wastewater.