FUOYE Journal of Engineering and Technology (FUOYEJET - Federal University Oye-Ekiti)
Not a member yet
287 research outputs found
Sort by
Design of Fuzzy Logic Based Relay for Distance Protection
Get PDFThe safe generation and distribution of power is the most desirable factor targeted by utility companies. Therefore, there is a serious concern for protection of the transmission line as well as the equipment involved. Several works have been carried out on protection to protect mostly human lives while some aimed at the use of microcontrollers to optimize the performance of a relay. Part of the conventional relay operation works was the work by IEEE Working Group I17 Incorrect Operation Reporting in which for 20 total events, for voltage above 400V, unnecessary trips during fault is 30%, unnecessary trip other than fault is 5%, and total misoperation is 35%. These results could be improved upon. As new technology surfaces more application areas also evolve such as the use of artificial intelligence tool like fuzzy logic to enhance the performance of a relay which is the key element in the switching operation of a power network. This fuzzy logic based relay shows considerable improvement on false trip phenomenon usually associated with the operations of a relay in which a total of 25 events were used to form the rule base for voltage ranging from 480V to 15kV, unnecessary trip fault is 2%, and total misoperation is less than 10%. In this work, the protection scheme proposed is for transmission line's distance protections relay whose operation is adaptive and directly controlled using fuzzy logic controller which is fault tolerant, directional, and least affected by power swing
Variable Structure Controller for Surface Ship Steering
Get PDFA Lyapunov approach to constructing switching surfaces for variable structure systems is investigated in this paper. The method guarantees sliding mode for any initial condition of the state vector and asymptotic stability is always achieved during sliding motion. An application for the design of a variable structure ship steering controller is carried out and simulation results are presented. The designed controller exhibits robustness as applied to a linear time-invariant ship model and a time varying non-linear ship model operating in an uncertain and time-varying environment
Construction and Leakage Detection of a Dome-Type Biogas Digester in a Village at Abuja, Nigeria
Get PDFThis work presents construction and leakage detection of dome-type biogas digester. The constructed biogas digester with local materials is rated at 10m3 capacity. The biogas digester foundation, cylindrical wall and dome vault were about 10 cm thick and made of high strength concrete in kilogram at ratio of cement, sharp sand and aggregate of 12 mm size as 111:1:1.2. The constructed biogas digester was pressure tested by using liquid manometer. The pressure gauge level difference of 48 cm (4.7 KN/m2) was obtained, which later dropped to less than 20 cm (1.96 KN/m2)indicating presence of leakage in the biogas digester. Cracks in the biogas digester were located after a careful examination at the cylindrical wall and dome top, which were scaled and sealed with wet cement. The pressure test wasagain conducted and yielded pressure gauge level difference of 60 cm(5.88 KN/m2), without dropping for over 20 minutes, which implies no leakage in the biogas digester
Kinetics of Gelatinized White Yam (Dioscorea Rotundata, Poir) During Convective Drying
Get PDFGelatinized white yam cubes, having a moisture content of 196% dry basis were dried in a convective dryer under different conditions of air temperature (40, 50, 60 and 70°C) and relative humidity (20 - 50%). There was no constant rate period throughout the entire drying period as drying took place entirely during a falling rate period. The effect of temperature was more pronounced than that of relative humidity. The drying data were fitted to five thin-layer drying models. The goodness of fit of the models were evaluated by comparing the percent mean relative deviation modulus (E%), RMSE, χ2 and R2 between their observed and predicted moisture ratio. The Binomial approximation of Fick's diffusion equation gave the best fit to the drying data as the highest values of R2 and the lowest values of χ2 and RMSE were consistently obtained with the Binomial model equation
Effects of Magnesium Variation and Heat Treatment on Mechanical and Micro-Structural Properties of Ductile Cast Iron
Get PDFThe effects of magnesium variation and austempering heat treatment on mechanical and microstructural properties of ductile iron produced using the rotary furnace were investigated. Varied quantity of magnesium-ferrosilicon in the range of 0.03 % to 0.06 % were used as nodulirizer to treat 4 kg mass of molten metal per ladle by sandwich process and poured into sand mould. Mechanical test (tensile, hardness, fatigue, impact and wear) and micro-structural examinations were carried out on the four samples produced. Samples C and D of 0.056% and 0.061% magnesium showed an improvement in their micro-structural properties due to the presence of more graphite nodules. Hence, they were observed to have exhibited better tensile strength of 598.07MPa and 609.03MPa. The fatigue strength also increased to 501.91MPa and 509.27MPa respectively. These two samples were further subjected to austempering heat treatment by heating to 850ºC for austenitization and soaked for homogenization for one hour at the temperature before quickly transferred into a salt bath of 50 % NaNO3 : 50 % NaCl maintained at 3600C and quenched for transformation for 1 hour before finally air cooled. Mechanical tests and micro-structural examinations were thereafter carried out. Sample C had an outstanding increase in tensile strength, from 598.07MPa to 891.22MPa, while specimen D increased from 609.03MPa to 898.76MPa. The results of abrasion test indicated that samples C and D had abrasion resistance increase from 2.20×10¹¹m² and 2.39×10¹¹m² to 2.35×10¹¹m² and 2.68×10¹¹ m² respectively after austempering. There were also relative increase in fatigue resistance and impact toughness for the two samples but with relative reduction in hardness from 47.7 to 44.2 and 50.3 to 47.4
Energy Audit of Asejire Community for a Small Hydropower Scheme
Get PDFEnergy is an important infrastructure for national development. In Nigeria the erratic power supply experienced, and especially in rural areas is an important concern. Energy audit is the assessment of the energy need and efficiency of a building. Hence, energy audit of Asejire community was conducted for developing a small hydropower scheme (SHP) for power generation. The household appliances used were determined, the appliances consuming the most energy in a rural setting were identified, buildings with high energy consumption were identified; and their energy need was evaluated. 1817 kW h was the daily energy consumption of the Asejire community with houses being the most energy consuming buildings by the community, while Nigerian Bottling Company (NBC) an industry in Asejire town had an average daily energy consumption of 29700 kW h. This gave a daily total energy consumption of 31517 kW h with a rated power of 1.389 MW. The energy need of the Asejire Community can be solved with the incorporation of a Small Hydropower Scheme (SHP) by utilizing the Asejire dam and thereby matching their energy demand with the energy supply from the Small Hydropower Scheme (SHP)
Production of Ductile Iron from Waste Sleeve Scraps for Automobile Applications
Get PDFThere is continuous demand for local production of quality automobile spare parts in the country nowadays. The current economic condition of the nation has placed more challenges on the indigenous foundry to improve on their technology to make automobile spare components accessible and affordable to the nation. This study examined the possibility of converting the indiscriminately dumped sleeve scraps from state of waste to ductile iron useful products thereby adding value to it. The mechanical properties of ductile iron produced from the sleeve scraps using local technology were determined and found comparable to that of international standard (ISO). Sleeve scraps were charged with graphite and FeSi into a rotary furnace and melted. Nodularization was achieved ising MgFeSi as an indigenous technology of the production process. The hypotheses of the study were tested and compared with the ISO standard of the grade of ductile iron and the findings revealed that Ductile iron that corresponds with the standard was successfully produced from solid waste (automobile sleeves scraps). It was recommended among others that the effort be made towards the conversion of sleeve scraps to ductile iron automobile components, in order to minimize the menace of environmental pollution which leads to numerous health hazards and mortality. Also, making automobile spare parts available to the end users and reduce its importatio
Determination of Hardness and Tensile Properties of Dissimilar Phase Structured Steel Weld
Get PDFThis work involves the use of submerged arc welding (SAW) technique in joining heat treated steel in alternate arrangement. The selected as-received steel was initially cut, machined and heat treated to develop a conventional microstructure prior to joining operation. All samples were subsequently characterized to investigate the effect of the process on the mechanical behaviors. 3360 Instron Universal Tensile testing machine was used for the tensile properties evaluation; Vickers’ microhardness testing machine was also used for the hardness evaluation at various zones. From the result, it was found that interchanging arrangement of the microstructures during welding yield better combined properties of the ultimate tensile strength, yield strength and with improvement in the strain-to-fracture of some of the samples. The adopted mechanism was also observed to yield better hardness property on the sample. This led to the recommendation of this technique to the oil and gas industry that need to transport their products via the giant water bodies to clients
Design, Fabrication and Performance Evaluation of Awning/Canopy for Thermal Comfortability
Get PDFThis paper presents the design, fabrication and performance evaluation of retractable awning/canopy system for thermal comfortability. It consists of frame (mild steel bars), linear actuator, fabric (acrylic), adapter, roller pathways and photo sensor (for easiness of control). After fabrication and coupling of the whole components of the retractable awning system, it was connected to the adapter and power source for performance test evaluation. It was observed that, the actuator arm which was coupled to the fabric began projecting outward and once the photo sensor was shaded from sunlight using a dark material, the fabric retracted into the roller. Also a reduced solar heat gain factor of 28.16 W was achieved by shading the window compared to the solar gain factor of 498.54 W before shading with a cooling load of 415.37 W. This can be incorporated into building plans especially those at the sunheating direction and tropical region to reduce inner-house temperature air-conditioner loading for longer life and efficient operation
Effect of Thermal Conductivity on Magnetohydrodynamic Heat and Mass Transfer in Porous Medium Saturated with Kuvshinshiki Fluid
Get PDFThe effects of Kuvshinshiki fluid on Magnetohydrodynamic (MHD) heat and mass transfer flow over a vertical porous plate with chemical reaction of nth order and thermal conductivity was carried out. The governing partial differential equations were solved numerically using implicit Crank-Nicolson method. A parametric study was performed to illustrate the impact of visco-elastic parameter, radiation parameter, thermal conductivity parameter, magnetic parameter, Prandtl number on the velocity,temperature and concentration profiles.The results were presented graphically with tabular presentations of the skin-friction,rate of heat and mass transfer which were all computed and discussed for different values of parameters of the problem. The numerical results revealed that the visco- elastic of Kuvshinshiki fluid type is growing as concentration profile increases, while the velocity and temperature profile falls ,then the radiation and thermal conductivity were growing as velocity and temperature increases. Also Sherwood number decreases as radiation increases but Sherwood number remains unchanged as thermal conductivity growing