Mechanical Engineering
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Mechanical Engineering
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Item DEVELOPMENT OF ALUMINIUM ALLOY (AA6061) COMPOSITES FOR AUTOMOBILE EXHAUST PIPE(Nigerian Journal of Engineering Science and Technology Research,, 2025) A. A. Ishola, M. S. Abolarin, J. Y. Jiya, and K. T. ObanimomoThis research addresses the limitations of aluminium alloy AA6061 in withstanding the harsh conditions of automotive exhaust systems. The study aims to develop a composite material with enhanced mechanical strength and corrosion resistance by reinforcing AA6061 with kaoline ore and masquerade leaves. Using the stir casting method, the alloy was combined with the reinforcements and cast into molds. The results revealed that the developed composites showed improved properties compared to the base alloy. Hardness increased from 95.4 HBW to 102.7 HBW, tensile strength rose to 270 N/mm², and yield strength to 240 N/mm². Corrosion resistance was significantly enhanced, with potential ranging from -300 mV to -550 mV, compared to -90 mV to -250 mV for the unreinforced alloy. Microstructural analyses confirmed uniform reinforcement distribution. The study recommends further optimization of reinforcement ratios and casting parameters to maximize performance for automotive applications, particularly in exhaust systems.Item Production of Biogas from Chicken and Goat Wastes(2019) N. W. Okafor, O. Adedipe, F. J. Usman, J. Y. Jiya, and R. O. Mamman.One of the problems facing the world today is waste management, particularly those generated from animals. Examples of such wastes include goat waste and chicken droppings. This paper presents the performance evaluation of five 32 litre capacity biogas digesters that were used to investigate the anaerobic digestion of chicken and goat wastes. Biogas was produced from chicken and goat wastes with different mixing ratios: 100:0 (Sample I), 30:70 (Sample II), 70:30 (Sample III), 50:50 (Sample IV) and 0:100 (Sample V) from digesters 1, 2, 3, 4 and 5 respectively. The digesters were charged differently with these wastes and the mesophilic ambient temperature range attained during the experiment were 26-38 oC and a slurry temperature of 25-32 oC. The result showed that the samples were capable of producing a total of 17.3, 44.3, 74.3, 86.2 and 113.2 litres of biogas respectively, using the 32 litre capacity digesters for 30 days. The result obtained from the gas production showed that sample IV produced the highest methane content of 63.3% followed by sample III with 59.4% and sample II with 59.2%. Sample I produced a methane content of 59.1% while sample V had the least methane content of 57.3%.Item SECURITY MANAGEMENT: THE ENGINEERING PERSPECTIVE(IEC, 2015) H. U. Ogboo; A. Nasir; J. Y. Jiya; H. T. AbdulkarimSecurity management is a difficult task as everyone agrees that security is a problem. As such, this work aims at addressing the ever increasing security challenge confronting us as individuals from the engineering perspective. Throughout human history, engineering has driven the advance of civilization. This can be seen from the metallurgists who ended the Stone Age to the shipbuilders who united the world’s people through travels and trades; the past witnessed many marvels of engineering prowess. As civilization grew, it became pertinent that the world became confronted with the challenge of survival and relevance and hence, the desire not to be cut out from the basic necessities of life and existence gave rise to devices by humanity to remain relevance and hence, the field of engineering owes it a responsibility to the world to see that this issue is sorted out as usual as it has always provided respite to the world.Item EFFECTS OF OXIDIZED SUCROSE CROSS-LINKED CASSAVA STARCH FILM ON THE PHOTOVOLTAIC PROPERTIES OF PEROVSKITE SOLAR CELLS(The Nigerian Institution of Mechanical Engineers (A Division of Nigerian Society of Engineers), 2021-09) J. Y. Jiya; J. S. Enaburekhan; M. T. Jimoh; E. C. Egwim; I. A. JosephDespite rapid progress in the perovskite solar cell efficiency, there have been concerns about issues which could affect the measurement accuracy and/or practical applications of these devices, amongst which are stability, scaling up (large area devices), and possible environmental effects related to the use of lead-based active material. Based on the findings from previous studies, an optimized biodegradable oxidized sucrose cross-linked cassava starch film layer with zirconium oxide is introduced as a desiccant and buffer against damp heat and thermal recycling. This modified photovoltaic device is capable of resisting ingress of moisture at elevated temperatures, withstanding temperature cycling without delamination, and as such, enables efficient and stable operation. The layers in the PSC were modified by replacing the conventional metallic counter electrode with a low-cost carbon counter electrode. The PSC device with the control architecture underwent a more rapid degradation, particularly within the first 288 hours though with a higher PCE than the modified device. However, in contrast, the PSC device with the buffer layer only degraded a small amount. The best device maintained 95% of its initial efficiency after exposure for 550 hours.Item A Fundamental Review of Trends in Perovskite Solar Cells Based on Introduction of Buffer Layers to Enhance Stability(JOURNAL OF SCIENCE TECHNOLOGY AND EDUCATION, 2020) J. Y. Jiya; J. S. Enaburekhan; M. T. Jimoh; E. C. EgwimPerovskite solar cells (PSCs), as photo-electric conversion devices, exhibit adequate power conversion efficiency (PCE) and low processing cost and have thus become one of the most promising devices to replace conventional silicon-based solar cells thereby addressing current prevailing energy issues. Despite rapid progress in the perovskite solar cell efficiency, there have been concerns about issues which could affect the measurement accuracy and/or practical applications of these devices, amongst which are stability, scaling up (large area devices), and possible environmental effects related to the use of lead-based active material. Current PSCs use nonbiodegradable petroleum-based polymer substrates, discarding of which will aggravate environmental pollution. In this study, a review of the fundamentals and progress in the perovskite solar cell (PSC) is discussed. The processing cost of metal electrode deposition in PSC is very costly, hence, the replacement of the metal electrode by some other low-cost counter electrode is discussed.Item TIMISATION OF PLASMA ARC CUTTING PROCESS OF AISI 304 STAINLESS STEEL USING DESIGN OF EXPERIMENT(The Nigerian Institution of Mechanical Engineers (A Division of Nigerian Society The Nigerian Institution of Mechanical Engineers (A Division of Nigerian Society), 2021) A. O. Nasir; R. O. Medupin; J. Y. Jiya; K. Okon; C. C. Ozoh; I. S. Sule; S. A. LawalOwing to its corrosion resistance capability, stainless steel stands out as a material of choice in food processing and other allied industries. However, cutting, during manufacturing activities, poses enormous challenge with regular thermal cutting processes. This study has optimized plasma arc cutting process of AISI 304 stainless steel using a full factorial experimental design. The input process parameters were Cutting Speed (CS), Cutting Current (CC) and Gas Pressure (GP) while the response variables were Material Removal Rate (MRR) and surface roughness. Analysis of Variance (ANOVA) was performed in order to identify the effect of each input process parameters on the response variables. ANOVA revealed that whereas CS made 31.1% contribution to surface roughness of the stainless steel, CC and GP only contributed as much as 31.7% and 28.2% respectively. CC had the most significant effect of 36.07% on MRR followed by GP and CS with 28.02% and 27.11% respectively. While the optimal cutting conditions for surface roughness were found to be 4000 mm/m for CS, 80 A for CC and 6 bar for GP, the optimal values for MRR were 4000 mm/m, 60 A and 6 bar for SC, CC and GP respectively. It can, therefore, be concluded that increase in cutting current favours increased material removal rate during plasma arc cutting processes of AISI 304 stainless steel.Item Heat Transfer Analysis of a Concentrated-Type Solar Dryer for Ginger(Journal of Science, GU J Sci, Part A,, 2024) I. Bori; J. Y. Jiya; A. M. Orah; S. Bako; M. O. OyebamijiIn recent years, global concern about the preservation of agricultural products for usage and exports through drying has been outstanding. Solar Parabolic Trough Collectors (SPTC) are used to dry various agricultural products for effective moisture removal. A heat transfer fluid (HTF) flows through a receiver tube pipe that absorbs solar radiation reflected from the stainless-steel sheet surfaces of the SPTC. In order to reduce the heat losses, the pipe was linked through a flexible, thermally insulated cross-linked polyethene pipe to the copper tubes inside the drying chamber. The heat transfer analysis of the SPTC is essential to understand the thermal behavior and its performance during the drying process. This paper examined the heat exchanges developed in the designed concentrated-type solar dryer, and the heat transfer rates in the receiver tube and the drying chamber, as well as the heat transfer coefficients for the solar drying of ginger, were determined. The thermal analysis of the convective heat exchanges within the receiver tube and the drying chamber is presented. The heat transfer coefficients hRec and hDC for the convective heat transfer process in the receiver tube and the drying chamber were 1372.48W/m.K and 17.60W/m.K, respectively. The dryer’s thermal efficiency was 30%, showing considerable moisture removal from the ginger samples. The mean temperature difference between the drying chamber and the ambient showed a considerable increase of about +11oC. This resulted in considerable moisture removal, and the final moisture content achieved by the concentrated solar dryer for the ginger samples was 11.1%, compared to the 23.74% achieved by the open-air solar (OAS) drying methodItem Statistical Optimization of Optical Property (Transparency) of Bleached, Oxidized Sucrose Cross-Linked Cassava Starch Film(AFIT Journal of Science and Engineering Research, 2022) J. Y. Jiya; J. S. Enaburekhan; M. T. Jimoh; E. C. Egwim; I. A. JosephThe present environmental pollution caused by non-degradable polymer films has prompted researches into the development of biodegradable polymer films. This study was able to develop a bleached, cross-linked film from native cassava starch. Hydrogen peroxide (H2O2) was added for bleaching to improve the transparency, oxidized sucrose was added for cross-linking and further oxidation while a moderated concentration of glycerol helps to improve the plasticity. In order to have a wider area of application of the film, the transparency was optimized using Box-Benkhen method under the response surface methodology (RSM) in Design Expert 11.0 software. UV-visible spectrophotometer analysis shows that the cassava starch film produced at the above process conditions retained 91.8 % of its transparency after 24 hours water immersionItem Effect of Cutting Speed and Feed Rate on Tool Wear Rate and Surface Roughness in Lathe Turning Process(International Journal of Engineering Trends and Technology (IJETT), 2015) O. A. Olugboji; M. S. Abolarin; J. Y. Jiya; S. O. Popoola; C. K. AjaniMachining is a vital part of the production process in the manufacturing industries. Turing operation was carried out on the mild steel to produce shaft of various diameters. The conditions applied during the turning operation include varying the cutting speed and feed rate while keeping other cutting variables like depth of cut constant. The results affirms that an increase in the cutting speed causes a decrease in the tool life, increase in the feed rate also affects the surface finish obtained.Item Development of a Test Rig for the Determination of Headloss and Friction Factor of Polyvinyl Chloride (PVC) Pipes(Journal of Energy Technologies and Policy, 2016) N. A. Musa; J. Y. Jiya; T. K. AderojuThis paper reports the design, construction and performance evaluation of a test rig for determining the head loss and friction factor of PVC pipes of different diameters (13mm, 19mm and 25mm) transporting water. On performance evaluation, friction factors of 0.0121, 0.0396 , 0.0171 and head losses of 37.8mm, 25.2mm and 12.6mm for 13mm, 19mm, and 25mm diameter PVC pipes respectively were obtained. Keywords: Head loss, friction factor, PVC pipes, test rig, water