Browsing by Author "Rabiu, A. B."
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Item Assessment of wind resource for possibility of small wind turbine installation in Ilorin, Nigeria(KKU ENGINEERING JOURNAL, 2015) Ajao, K. R.; Rabiu, A. B.; Gbadeyan, A. A.; Ajibola, G. O.; Olabiyi, A. I.This work presents an evaluation of the wind characteristics of a particular location in University of Ilorin, Nigeria. The daily wind data for this location (lat. 8.48N, long. 4.67E) at three different heights of 10 m, 20 m and 30 m were measured over a period of six months. Although there seems to be flashes of higher wind speed at H = 20 m due to not too far away trees having more leaves up there and causing occasional turbulence, consistent wind availability still occurs at H = 30 m. The mean wind speed obtained at H = 30 m was 5.5 m/h (2.5 m/s) which is close to the cut-in wind speed of most modern commercially available small wind turbines. The results obtained ascertained that the wind speed increases with height that produces more power and the resulting wind profile may be useful in determining the type of wind turbine that may be suitable for this location. The adoption of wind energy technology will improve electricity supply, ensure greater energy mix and enhance the overall economic development in Nigeria.Item Combustion characteristics of selected tropical wood residues in relation to particle size(Published by Journal of Solid Waste Technology and Management, Department of Civil Engineering, Widener University, United States, 2018) Rabiu, A. B.; Lasode, O. A.; Ajimotokan, H. A.; Afolayan, V. A.Evaluation of combustion properties of biomass wood species is becoming more needful to improve and enhance the development of their utilisation as energy fuels. The study evaluates the particle size effect on energy potentials of commercially available tropical wood residues - Teak (Tectona grandis, TG), Apa (Afzelia africana, AA) and Ara (Albizia pedicellaris, AP), collected from Ilorin, Nigeria. These tropical wood species were pulverised into different particle sizes of less than 0.25 mm, 0.25 - 0.5 mm and 0.5 - 1.0 mm. The moisture content, volatile matter, ash content, fixed carbon, calorific (heating) value and elemental composition of these wood species samples for different particle sizes were evaluated in accordance to ASTM standards. The particle size of 0.5 - 1.0 mm presented the best quality within the considered particle sizes. Sample AA has the highest calorific value of 30.03 MJ/kg at particle size of 0.5 - 1.0 mm, while sample TG has lowest energy value at less than 0.25 mm with energy content of 8.84 MJ/kg. The results obtained revealed that particle size plays a significantly role in combustion properties of woody biomass residues as solid fuel.Item Densification of tropical wood residues for the development of solid fuels(Proceedins of International Conference on Sustainability, Energy & Environment-Hawaii 2019, 2019) Rabiu, A. B.; Lasode, O. A.; Popoola, O. T.; Babatunde, O. P.; Ajimotokan, H. A.Densification of materials through pelletisation, briquetting and cubing to form strong and durable bonding products with greater structural homogeneity, better handling and durability properties has attracted the attention of researchers in recent past. The present work focused on conversion of residues of some tropical wood species to energy fuel through pelletisation. The woody-biomass species studied were Apa (Afzelia Africana, AA), Iya (Daniella oliveri, DO) and Arira (Detarium microcarpum, DM) which were sourced in Nigeria. The samples were prepared in different sizes of less than 0.50 mm, 0.50 - 1.00 mm and 1.00 - 1.70 mm after drying in a laboratory environment. The different particle sizes were forced into a prepared die using gelatinised starch as binder. Higher heating value (HHV), impact resistance index (IRI) and water resistance test were obtained for all samples with and without binder. The average HHV of pellets produced from DM was found to be 26.53 MJ/kg without binder, which is the highest among the three samples, showing that DM may have higher lignin content. However, pellet samples AA produced with binder has average HHV of 25.41 MJ/kg which is highest among the three samples. Result showed that IRI increases as particle size decreases for pellets produced without binder, while for pellet with binder, IRI increases as the particle size increases. Result of water resistance test showed that the disintegration time increases as particle size decreases. The basic physical properties that enhance handling and transportation operations of wood pellets have been achieved when compared with standard.Item Effect of using vegetable oils as quenching media for pure commercial aluminium(Proceedings of International Conference on Clean Technology & Engineering Management, 2012) Adekunle, A. S.; Odusote, J. K.; Rabiu, A. B.This paper presents the effects of rate of heat extraction by groundnut, melon, palm kernel, shea butter and palm oils on the mechanical properties of various samples of pure commercial aluminium heat treated at 200°C, 250°C, 300°C and 350°C. Muffle furnace equipped with digital thermometer and thermocouple was used for the heat treatment. Tensile strength and hardness tests were carried out using Instron Universal Tester and Vickers hardness methods, respectively. Results obtained from the experiment were presented graphically. The results showed that palm kernel oil cools faster at 200°C and 250°C, while palm oil and shea butter oil quench faster at 300°C and 350°C, respectively. Palm kernel oil offers the highest elongation at 200°C, while at 350°C shea butter oil gave the best result. The best among the bio-quenching oils in providing good ductility is shea butter oil at 200°C, while at 300°C and 350°C groundnut oil give the best result. Highest hardness values were obtained from samples quenched in melon oil between 200°C-300°C. However, these values decreased with increased heating temperature probably due to density and viscosity variation with temperature rise. Similar observations were made on most of other samples quenched in other bio-quenching oils used in this experiment. This study shows that these locally available vegetable oils have promising potentials to serve as a possible replacement for non-biodegradable mineral oils in many applicationsItem EFFECT OF VEGETABLE OIL QUENCHANTS ON THE PROPERTIES OF ALUMINUM DURING SOLUTION HEAT TREATMENT(Journal of Mechanical Engineering and Sciences (JMES), 2015) Odusote, J. K.; Adekunle, A. S.; Rabiu, A. B.Proper selection of appropriate quenching media can result in improved mechanical properties of pure commercial aluminum after solution heat treatment. This paper presents the effect of heat extraction by groundnut, melon, palm kernel, shea butter and palm oils on the mechanical properties of various samples of pure commercial aluminum heat treated at 200 °C, 250 °C, 300 °C and 350° C. A muffle furnace equipped with a digital thermometer and a thermocouple was used for the solution heat treatment. Tensile strength and hardness tests were carried out using an Instron Universal Tester and Vickers hardness methods, respectively. The results showed that palm kernel oil cools faster at 200 °C and 250 °C, while palm oil and shea butter oil quench faster at 300 °C and 350 °C, respectively. Solution heat treatment with palm kernel oil offered the highest percentage elongation at 200 °C, while at 350 °C shea butter oil gave the best percentage elongation. The best among the bio-quenching oils in providing good ductility is shea butter oil at 200 °C, while at 300 °C and 350 °C groundnut oil gives the best result. Highest hardness values were obtained from samples quenched in melon oil between 200 °C and 300 °C. However, these values decreased with increased heating temperature, probably due to the density and viscosity variation with temperature rise. Similar observations were made on other samples quenched in other bio-quenchant oils used in this experiment. This study shows that locally available vegetable oils have promising potential to serve as a possible replacement for nonbiodegradable mineral oils in many applications.Item The effects of storage time on fuel properties of Jatropha biodiesel blends(Journal of Bioresources and Bioproducts, 2018) Ajimotokan, H. A.; Rabiu, A. B.; Lawal, A. R.This study investigates the effects of storage time on fuel properties of biodiesel made from Jatropha oil and its blends with mineral diesel at different percentage compositions. The influence of storage stability on selected fuel properties such as kinematic viscosity, density, pour, cloud and flash points for Jatropha biodiesel and its blends at varying storage times were investigated using standard test methods. The biodiesel obtained through trans-esterification of Jatropha oil was blended with mineral diesel to obtain fractional samples of B20 (20% biodiesel blend), B40 (40% biodiesel blend), B60 (60% biodiesel blend) and B100 (100% neat biodiesel). Results show that kinematic viscosity and density increase for each blend over the 12 weeks of storage period. Flash, cloud and pour points decrease for each blend over the period of study. B20 was observed to be the optimum blend mix as its fuel properties were relatively unchanged over the storage period when compared to that of mineral diesel. It can be implied from the research that while properties like kinematic viscosity and density deteriorate with time; flash, cloud and pour points are observed to have improved with storage time.Item Evaluation of Mechanical Properties of Medium Carbon Steel Quenched in Water and Oil(AU Journal of Technology, 2012) Odusote, J. K.; Ajiboye, T. K.; Rabiu, A. B.Samples of medium carbon steel were examined after heating between 900ºC980ºC and soaked for 45 minutes in a muffle furnace before quenching in palm oil and water separately. The mechanical behavior of the samples was investigated using universal tensile testing machine for tensile test and Vickers pyramid method for hardness testing. The microstructure of the quenched samples was studied using optical microscope. The tensile strength and hardness values of the quenched samples were relatively higher than those of the as-cast samples, suggesting improved mechanical properties. However, samples quenched in palm oil displayed better properties compared with that of water-quenched samples. This behavior was traced to the fact that the carbon particles in palm oil quenched samples were more uniform and evenly distributed, indicating the formation of more pearlite structure, than those quenched in water and the as-received samples.Item Use of hand tools(University of Ilorin Publishing House, University of Ilorin, Ilorin, Nigeria, 2017) Ajao, K. R.; Rabiu, A. B.