Olufemi Koya - Academia.edu (original) (raw)
Papers by Olufemi Koya
Agricultural Engineering International: The CIGR Journal, 2019
A mathematical model for predicting the performance efficiency of an integrated palm-nut cracker ... more A mathematical model for predicting the performance efficiency of an integrated palm-nut cracker and kernel-shell separator was developed using dimensional analysis based on Buckingham’s π theorem. The developed performance model was iterated in Matrix Laboratory (MATLAB), to predict the efficiencies, by varying the parameters of the materials in contact. The predicted performance efficiencies ranged between 88.26%-99.98%, while the evaluated performance efficiencies were in the range of 56.16%-96.57%. The correlation between the predicted and experimental numerical values using MINITAB17 suggested relationship and validity of the developed model (optimum r = 99.6%).
Effective separation of palm kernel and shell is an important process in the downstream industria... more Effective separation of palm kernel and shell is an important process in the downstream industrial utilization of the constituents. In view of the limitations of the conventional wet separators, a rotary separator employing a multi-cyclic separation process was developed for the dry mixture. Machine parts were designed following standard engineering principles for part-sizing, using locally available materials. Cracked palm nut mixture was classified by sieve analysis, and the fractions retained on the 10 and 15 mm sieves were used for the evaluation of the machine performance. Operating the separator at 55 rpm yielded kernel recovery and kernel purity of 96% and 42.86%, respectively, for the mixture retained on 10 mm sieves. Corresponding shell recovery, shell purity, separation efficiency and throughput capacity, at the same speed were 100, 81.71, 78.45 % and 277 kg/h, respectively. Separation of the mixture retained on 15 mm sieve was feasible at 60 rpm with kernel recovery and k...
Effective separation of the cracked palm nut mixture is an important process in the downstream ut... more Effective separation of the cracked palm nut mixture is an important process in the downstream utilisation of the constituent palm kernel and shell in some existing and emerging agro-economy. Whilst, the conventional wet separators are sophisticated and energy inefficient, the dry systems are at experimental stages and are inadequate for separating kernel and shell of comparable sizes. However, the difference in the path variables of particles of same size, but different shapes, in circular motion, suggests the possibility of separating the dry mixture in a rotating trammel with a co-axial spout. Based on the theory, the study investigated the dispatch angles for palm kernel and shell from a friction lining on the inner curved surface of drums of different diameters and rotating speeds. A built experimental facility allowed estimation of the dispatch angle for particles placed on the lining. The results show that palm kernels oscillate and move axially with the dispatch angle increa...
Applied Engineering Letters : Journal of Engineering and Applied Sciences
Separation theory describing the motions of palm kernel and shell on rotating incline was analyse... more Separation theory describing the motions of palm kernel and shell on rotating incline was analysed. Two series of differential equations, in order to obtain the dispatch angles of kernel and shell for the separation process were developed respectively. The differences in the motions and physical features of the particles formed the premise for separation. The results obtained from the theory showed a possibility of product separation within the approximate ranges of dispatch angles between 25 and 90 0 for kernels and shells on rotating incline, with specified slide limit, angular velocity and radius of the incline, and comparisons were made between the theoretical and experimental results. The dispatch angles obtained from both theory and experiment reasonably showed significant agreement and therefore suggested validity of the developed theory.
Volume 9: Mechanics of Solids, Structures, and Fluids, 2019
This study investigates the dynamic response of AA2519 aluminum alloy in T6 temper condition duri... more This study investigates the dynamic response of AA2519 aluminum alloy in T6 temper condition during plastic deformation at high strain rates. The aim was to determine how the T6 temper condition affects the flow stress response, strength properties and microstructural morphologies of the alloy when impacted under compression at high strain rates. The specimens (with aspect ratio, L/D = 0.8) of the as-cast alloy used were received in the T8 temper condition and further heat-treated to the T6 temper condition based on the standard ASTM temper designation procedures. Split-Hopkinson pressure bar experiment was used to generate true stress-strain data for the alloy in the range of 1000–3500 /s strain rates while high-speed cameras were used to monitor the test compliance with strain-rate constancy measures. The microstructures of the as received and deformed specimens were assessed and compared for possible disparities in their initial microstructures and post-deformation changes, respe...
2013 Africon, 2013
ABSTRACT This paper discusses the design of a low-cost educational robot arm system. The robotic ... more ABSTRACT This paper discusses the design of a low-cost educational robot arm system. The robotic arm was developed as an undergraduate project at the Obafemi Awolowo University. The robotic arm system is a five Degree of Freedom (DOF) system and is fully functional having all of its joints (apart from the gripper) capable of 360° movement. The paper shows how cost was reduced in the design of the robot. The paper posits that through the process of building such a robot system, students can be introduced to sustainability, machine design, basic mechanics, electronics, and computing. A cost breakdown and analysis of the robotic arm developed is also given. In conclusion, the studies show that an educational robotic arm made using locally-available materials is not only feasible and viable for teaching robotics especially at early stages, but can be low-cost.
Public Universities in Southwestern Nigeria are densely populated student-resident campuses, so t... more Public Universities in Southwestern Nigeria are densely populated student-resident campuses, so that provision of regular potable water and electricity are important, but power supply is not optimally available for all the necessary activities. This study assesses the hydropower potential of the water distribution networks in the Universities, with the view to augmenting the inadequate power supplies. The institutions with water distribution configuration capable of accommodating in-pipe turbine are identified; the hydropower parameters, such as the flow characteristics and the pipe geometry are determined to estimate the water power. Global positioning device is used in estimating the elevations of the distribution reservoirs and the nodal points. The hydropower potential of each location is computed incorporating Lucid ® Lift-based spherical turbine in the pipeline. From the analysis, the lean and the peak water power are between 1.92-3.30 kW and 3.95-7.24 kW, respectively, for re...
The work evaluates the response of the heart rate of non-mechanics handling some specific loads i... more The work evaluates the response of the heart rate of non-mechanics handling some specific loads in the common postures employed during road-side repair of automobile and later, the result was validated with the auto-mechanics during repair activities. The purpose is to specify the safe work-impulse of auto-mechanics in the common postures, such as, bending, stooping and supine posture, used during roadside repair. The safe work-impulse was determined for preselected healthy non-mechanics of the classified age groups who gave informed consent. Increase in heart rates at exhaustion of non-mechanics in each age group, in lifting predetermined loads were measured using digital premium pressure monitor with a comfit cuff. Consequently, the work-impulse charts for the load classifications and different age-groups were developed for the different postures. The heart rates of the auto-mechanics performing specific tasks during engine repairs were then measured to determine the equivalent wo...
Applied engineering letters, 2020
Separation theory describing the motions of palm kernel and shell on rotating incline was analyse... more Separation theory describing the motions of palm kernel and shell on rotating incline was analysed. Two series of differential equations, in order to obtain the dispatch angles of kernel and shell for the separation process were developed respectively. The differences in the motions and physical features of the particles formed the premise for separation. The results obtained from the theory showed a possibility of product separation within the approximate ranges of dispatch angles between 25 and 90 0 for kernels and shells on rotating incline, with specified slide limit, angular velocity and radius of the incline, and comparisons were made between the theoretical and experimental results. The dispatch angles obtained from both theory and experiment reasonably showed significant agreement and therefore suggested validity of the developed theory.
Aim: The study evaluated the relevant/corresponding anthropometric characteristics of the people ... more Aim: The study evaluated the relevant/corresponding anthropometric characteristics of the people involved in engine-repair activities. The study was carried out on the selected roadside auto-engine repairers along Lagos-Ibadan express way, in Nigeria. This was with a view to providing ergonomic design data for optimal working condition among this set of workforce and redesigning the mechanics inspection-pit. Material and methods: The static and the functional anthropometric characteristics of the mechanics were measured. The data obtained from 110 auto-mechanics, randomly selected, were employed to evaluate efficient design parameter for roadside workstations. Results: The results indicated that inspection-pit is about 1626 mm deep; seat height ranges between 375 mm and 405 mm; optimal work posture sitting is between 483 mm and 622 mm. Conclusions: Adopting the data presented in this paper in optimizing the auto-mechanics working conditions for effective workplace comfort and produc...
Journal of Engineering Studies and Research
This paper presents the results from experimental validation of numerical simulation of a concept... more This paper presents the results from experimental validation of numerical simulation of a concept wave energy converter for low amplitude sea waves. The device was conceived to contain a wave amplifying device (WAD) to magnify the wave height of incident waves while point absorber buoy(s) efficiently harness the wave energy for electricity production. The validation results show that the optimum aperture angle for the WAD is 45±2 degree, and wave height magnification of 170% is possible. The optimal buoy shape for the device was confirmed as concave wedge buoy. The combination of the two in a single device shall make economical the harnessing of low amplitude waves.
Applied Engineering Letters : Journal of Engineering and Applied Sciences
Nigeria is currently experiencing energy deficit in terms of electrification. Development of rene... more Nigeria is currently experiencing energy deficit in terms of electrification. Development of renewable energy sources such as Sea wave energy may help augment this deficit. This paper set to investigate wave energy potential of the coast of Nigeria. Data required for estimating the wave energy potential of the coastal waters of Nigeria were obtained from WAVEWATCH III © wave generation model. The wave climate data were analyzed using basic statistical analysis such as average, mean, and range. Due to the scarcity of reliable measured wave climate data, an effort was made to investigate the relationship the mean monthly wave power may have with mean monthly rainfall. Establishing a good level of correlation will provide an alternative mean of forecasting wave power for the coastal region. The results show that the mean annual wave power magnitude generally decreases from the west coast (at 10.74 kW/m) to the east coast (at 5.64 kW/m) for the reference points considered. The most energetic months occurs during the rainy season while the least energetic months occur during the dry season. There is a strong positive correlation between mean monthly wave power and mean monthly rainfall at 5% significant level.
International Journal of Marine Engineering Innovation and Research
⎯ this research investigates the optimal buoy shape for a conceptual point absorber Wave Energy C... more ⎯ this research investigates the optimal buoy shape for a conceptual point absorber Wave Energy Converter (WEC) for harnessing low amplitude sea waves characteristic of the Gulf of Guinea coast. It has been established that shape of buoy is one of the main parameter affecting the efficiency of a point absorber WEC. Based on best buoy shapes as reported in literature, two shapes are selected for comparison: cone-cylinder composite buoy and Concave wedge shaped buoy. The WEC's buoy and the power take off were mathematically modelled as a mass-spring-damper system. The buoys hydrodynamic coefficients were computed using strip theory, while the simulation in the time domain was executed using MATLAB. Impute parameters referred to as the sea states, in five levels, were described by the significant wave height Hs and the corresponding energy period Te, typical of the gulf. Output parameters are displacement, velocity, acceleration and force of the buoys, as well as the instantaneous power output of the WEC. For the levels considered, the optimum sea state for the two buoys peaked at level 4 (Hs = 1.5 m, Te = 14 s), with concave wedge buoy having an optimal power output of 8 kW while that of cone-cylinder being 3.7 kW. For the other levels the wedge buoy also consistently gives relatively greater power output than the cone cylinder buoy.
Research in Agricultural Engineering
This paper reports on the design of fabrication and testing of a machine for cottage level produc... more This paper reports on the design of fabrication and testing of a machine for cottage level production of pellets from cassava mash. The pelletizer consists of a barreled screw auger which compresses cassava mash against perforated end plate, through which the pellets are pelletized. The result derived from the calculated design parameters (shaft diameter, tensile stress, torque, screw length, volumetric capacity mass flow rate and power rating) were used for the fabrication. The testing of the pelletizer was determined in terms of throughput of the machine, against the moisture content of the mash (18, 20 and 22% w.b.), die size (4, 6 and 8 mm) and the auger speed (90, 100 and 120 rpm). Test results showed that the pellets with the best quality attributes were obtained from cassava mash at 18% moisture content (w.b.) through the 4 mm die at 90 rpm and a maximum throughput of 54 kg/h.
Engineering Science and Technology, an International Journal
The research models and simulates in-pipe turbine hydropower harnessing possibilities in water di... more The research models and simulates in-pipe turbine hydropower harnessing possibilities in water distribution networks of the sites under investigation considering in-pipe lift-based spherical turbine. The hydrofoil profile of the turbine is generated using National Advisory Committee for Aeronautics (NACA) aerofoil generator. Consequently, a Computer-Aided Design (CAD) model of the in-line lift-based spherical turbine is then developed and simulated, based on the peak and lean period of the vol-umetric discharge rates using commercial computational fluid dynamics software (Autodesk Simulation CFD Ò). The time series of power outputs are computed from the time series of discharge variations. A lift-based spherical turbine with NACA 0020 foil cross-section appears appropriate for extraction of energy in the water distribution pipelines. Furthermore, the minimum and maximum percentage head loss due to insertion of the turbine is about 1.94% at lean flow rates and 9.70% at the peaks for 250 mm pipelines. The available power was found out to depend on the density of the turbine blades material, flow rate, and the pipe diameter. The estimated lean and the peak electric power are about 415 and 1663 W, respectively, using aluminium foil blades while stainless steel foil produces about 242 and 1080 W in the 250 mm pipe. Ó 2018 Karabuk University. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. SUMMARY 1.0. Abstract It is proposed to explore the use of open distance learning modules in p... more 1. SUMMARY 1.0. Abstract It is proposed to explore the use of open distance learning modules in promoting skills acquisition in two vocational areas – motor vehicle repairs and building maintenance by artisans-in-training at the vocational enterprise institutions (VEIs) being set up by the Federal Ministry of Education and university undergraduates to be apprenticed to master artisans. The strategic objectives of the project are to develop and place on the project website ODL modules for promoting the acquisition of vocational skills, enhancing the theoretical knowledge of artisans in motor vehicle repairs and building maintenance through the provision of ODL instruction via video conferencing by university lecturers to vocational enterprise institutions in Osun and Oyo States and improving the practical skills of university undergraduates in mechanical engineering and civil engineering departments through apprenticeships to master artisans located in Osun and Oyo States with consta...
The development of an electromechanical device employing a novel single unit operation to agglome... more The development of an electromechanical device employing a novel single unit operation to agglomerate chocolate drink powder is reported. The machine admits cocoa powder and sugar granules into an electrically heated chamber, whereby a ribbon conveyor stirs and moves the mixture to the discharge chute. Optimal process conditions were: barrel temperature, 180oC; cocoa powder to sugar ratio, 1:4; and sugar particle sizes, 260 m and 360 μm.The experimental agglomerates had shorter reconstitution times, superior degrees of consolidation, the same range of bulk and tap densities, and similar sensory quality compared with some commercial (international) brands of chocolate beverage products. The machine provides a simple yet viable technology for agglomeration of chocolate drink powders
Agricultural Engineering International: The CIGR Journal, 2019
A mathematical model for predicting the performance efficiency of an integrated palm-nut cracker ... more A mathematical model for predicting the performance efficiency of an integrated palm-nut cracker and kernel-shell separator was developed using dimensional analysis based on Buckingham’s π theorem. The developed performance model was iterated in Matrix Laboratory (MATLAB), to predict the efficiencies, by varying the parameters of the materials in contact. The predicted performance efficiencies ranged between 88.26%-99.98%, while the evaluated performance efficiencies were in the range of 56.16%-96.57%. The correlation between the predicted and experimental numerical values using MINITAB17 suggested relationship and validity of the developed model (optimum r = 99.6%).
Effective separation of palm kernel and shell is an important process in the downstream industria... more Effective separation of palm kernel and shell is an important process in the downstream industrial utilization of the constituents. In view of the limitations of the conventional wet separators, a rotary separator employing a multi-cyclic separation process was developed for the dry mixture. Machine parts were designed following standard engineering principles for part-sizing, using locally available materials. Cracked palm nut mixture was classified by sieve analysis, and the fractions retained on the 10 and 15 mm sieves were used for the evaluation of the machine performance. Operating the separator at 55 rpm yielded kernel recovery and kernel purity of 96% and 42.86%, respectively, for the mixture retained on 10 mm sieves. Corresponding shell recovery, shell purity, separation efficiency and throughput capacity, at the same speed were 100, 81.71, 78.45 % and 277 kg/h, respectively. Separation of the mixture retained on 15 mm sieve was feasible at 60 rpm with kernel recovery and k...
Effective separation of the cracked palm nut mixture is an important process in the downstream ut... more Effective separation of the cracked palm nut mixture is an important process in the downstream utilisation of the constituent palm kernel and shell in some existing and emerging agro-economy. Whilst, the conventional wet separators are sophisticated and energy inefficient, the dry systems are at experimental stages and are inadequate for separating kernel and shell of comparable sizes. However, the difference in the path variables of particles of same size, but different shapes, in circular motion, suggests the possibility of separating the dry mixture in a rotating trammel with a co-axial spout. Based on the theory, the study investigated the dispatch angles for palm kernel and shell from a friction lining on the inner curved surface of drums of different diameters and rotating speeds. A built experimental facility allowed estimation of the dispatch angle for particles placed on the lining. The results show that palm kernels oscillate and move axially with the dispatch angle increa...
Applied Engineering Letters : Journal of Engineering and Applied Sciences
Separation theory describing the motions of palm kernel and shell on rotating incline was analyse... more Separation theory describing the motions of palm kernel and shell on rotating incline was analysed. Two series of differential equations, in order to obtain the dispatch angles of kernel and shell for the separation process were developed respectively. The differences in the motions and physical features of the particles formed the premise for separation. The results obtained from the theory showed a possibility of product separation within the approximate ranges of dispatch angles between 25 and 90 0 for kernels and shells on rotating incline, with specified slide limit, angular velocity and radius of the incline, and comparisons were made between the theoretical and experimental results. The dispatch angles obtained from both theory and experiment reasonably showed significant agreement and therefore suggested validity of the developed theory.
Volume 9: Mechanics of Solids, Structures, and Fluids, 2019
This study investigates the dynamic response of AA2519 aluminum alloy in T6 temper condition duri... more This study investigates the dynamic response of AA2519 aluminum alloy in T6 temper condition during plastic deformation at high strain rates. The aim was to determine how the T6 temper condition affects the flow stress response, strength properties and microstructural morphologies of the alloy when impacted under compression at high strain rates. The specimens (with aspect ratio, L/D = 0.8) of the as-cast alloy used were received in the T8 temper condition and further heat-treated to the T6 temper condition based on the standard ASTM temper designation procedures. Split-Hopkinson pressure bar experiment was used to generate true stress-strain data for the alloy in the range of 1000–3500 /s strain rates while high-speed cameras were used to monitor the test compliance with strain-rate constancy measures. The microstructures of the as received and deformed specimens were assessed and compared for possible disparities in their initial microstructures and post-deformation changes, respe...
2013 Africon, 2013
ABSTRACT This paper discusses the design of a low-cost educational robot arm system. The robotic ... more ABSTRACT This paper discusses the design of a low-cost educational robot arm system. The robotic arm was developed as an undergraduate project at the Obafemi Awolowo University. The robotic arm system is a five Degree of Freedom (DOF) system and is fully functional having all of its joints (apart from the gripper) capable of 360° movement. The paper shows how cost was reduced in the design of the robot. The paper posits that through the process of building such a robot system, students can be introduced to sustainability, machine design, basic mechanics, electronics, and computing. A cost breakdown and analysis of the robotic arm developed is also given. In conclusion, the studies show that an educational robotic arm made using locally-available materials is not only feasible and viable for teaching robotics especially at early stages, but can be low-cost.
Public Universities in Southwestern Nigeria are densely populated student-resident campuses, so t... more Public Universities in Southwestern Nigeria are densely populated student-resident campuses, so that provision of regular potable water and electricity are important, but power supply is not optimally available for all the necessary activities. This study assesses the hydropower potential of the water distribution networks in the Universities, with the view to augmenting the inadequate power supplies. The institutions with water distribution configuration capable of accommodating in-pipe turbine are identified; the hydropower parameters, such as the flow characteristics and the pipe geometry are determined to estimate the water power. Global positioning device is used in estimating the elevations of the distribution reservoirs and the nodal points. The hydropower potential of each location is computed incorporating Lucid ® Lift-based spherical turbine in the pipeline. From the analysis, the lean and the peak water power are between 1.92-3.30 kW and 3.95-7.24 kW, respectively, for re...
The work evaluates the response of the heart rate of non-mechanics handling some specific loads i... more The work evaluates the response of the heart rate of non-mechanics handling some specific loads in the common postures employed during road-side repair of automobile and later, the result was validated with the auto-mechanics during repair activities. The purpose is to specify the safe work-impulse of auto-mechanics in the common postures, such as, bending, stooping and supine posture, used during roadside repair. The safe work-impulse was determined for preselected healthy non-mechanics of the classified age groups who gave informed consent. Increase in heart rates at exhaustion of non-mechanics in each age group, in lifting predetermined loads were measured using digital premium pressure monitor with a comfit cuff. Consequently, the work-impulse charts for the load classifications and different age-groups were developed for the different postures. The heart rates of the auto-mechanics performing specific tasks during engine repairs were then measured to determine the equivalent wo...
Applied engineering letters, 2020
Separation theory describing the motions of palm kernel and shell on rotating incline was analyse... more Separation theory describing the motions of palm kernel and shell on rotating incline was analysed. Two series of differential equations, in order to obtain the dispatch angles of kernel and shell for the separation process were developed respectively. The differences in the motions and physical features of the particles formed the premise for separation. The results obtained from the theory showed a possibility of product separation within the approximate ranges of dispatch angles between 25 and 90 0 for kernels and shells on rotating incline, with specified slide limit, angular velocity and radius of the incline, and comparisons were made between the theoretical and experimental results. The dispatch angles obtained from both theory and experiment reasonably showed significant agreement and therefore suggested validity of the developed theory.
Aim: The study evaluated the relevant/corresponding anthropometric characteristics of the people ... more Aim: The study evaluated the relevant/corresponding anthropometric characteristics of the people involved in engine-repair activities. The study was carried out on the selected roadside auto-engine repairers along Lagos-Ibadan express way, in Nigeria. This was with a view to providing ergonomic design data for optimal working condition among this set of workforce and redesigning the mechanics inspection-pit. Material and methods: The static and the functional anthropometric characteristics of the mechanics were measured. The data obtained from 110 auto-mechanics, randomly selected, were employed to evaluate efficient design parameter for roadside workstations. Results: The results indicated that inspection-pit is about 1626 mm deep; seat height ranges between 375 mm and 405 mm; optimal work posture sitting is between 483 mm and 622 mm. Conclusions: Adopting the data presented in this paper in optimizing the auto-mechanics working conditions for effective workplace comfort and produc...
Journal of Engineering Studies and Research
This paper presents the results from experimental validation of numerical simulation of a concept... more This paper presents the results from experimental validation of numerical simulation of a concept wave energy converter for low amplitude sea waves. The device was conceived to contain a wave amplifying device (WAD) to magnify the wave height of incident waves while point absorber buoy(s) efficiently harness the wave energy for electricity production. The validation results show that the optimum aperture angle for the WAD is 45±2 degree, and wave height magnification of 170% is possible. The optimal buoy shape for the device was confirmed as concave wedge buoy. The combination of the two in a single device shall make economical the harnessing of low amplitude waves.
Applied Engineering Letters : Journal of Engineering and Applied Sciences
Nigeria is currently experiencing energy deficit in terms of electrification. Development of rene... more Nigeria is currently experiencing energy deficit in terms of electrification. Development of renewable energy sources such as Sea wave energy may help augment this deficit. This paper set to investigate wave energy potential of the coast of Nigeria. Data required for estimating the wave energy potential of the coastal waters of Nigeria were obtained from WAVEWATCH III © wave generation model. The wave climate data were analyzed using basic statistical analysis such as average, mean, and range. Due to the scarcity of reliable measured wave climate data, an effort was made to investigate the relationship the mean monthly wave power may have with mean monthly rainfall. Establishing a good level of correlation will provide an alternative mean of forecasting wave power for the coastal region. The results show that the mean annual wave power magnitude generally decreases from the west coast (at 10.74 kW/m) to the east coast (at 5.64 kW/m) for the reference points considered. The most energetic months occurs during the rainy season while the least energetic months occur during the dry season. There is a strong positive correlation between mean monthly wave power and mean monthly rainfall at 5% significant level.
International Journal of Marine Engineering Innovation and Research
⎯ this research investigates the optimal buoy shape for a conceptual point absorber Wave Energy C... more ⎯ this research investigates the optimal buoy shape for a conceptual point absorber Wave Energy Converter (WEC) for harnessing low amplitude sea waves characteristic of the Gulf of Guinea coast. It has been established that shape of buoy is one of the main parameter affecting the efficiency of a point absorber WEC. Based on best buoy shapes as reported in literature, two shapes are selected for comparison: cone-cylinder composite buoy and Concave wedge shaped buoy. The WEC's buoy and the power take off were mathematically modelled as a mass-spring-damper system. The buoys hydrodynamic coefficients were computed using strip theory, while the simulation in the time domain was executed using MATLAB. Impute parameters referred to as the sea states, in five levels, were described by the significant wave height Hs and the corresponding energy period Te, typical of the gulf. Output parameters are displacement, velocity, acceleration and force of the buoys, as well as the instantaneous power output of the WEC. For the levels considered, the optimum sea state for the two buoys peaked at level 4 (Hs = 1.5 m, Te = 14 s), with concave wedge buoy having an optimal power output of 8 kW while that of cone-cylinder being 3.7 kW. For the other levels the wedge buoy also consistently gives relatively greater power output than the cone cylinder buoy.
Research in Agricultural Engineering
This paper reports on the design of fabrication and testing of a machine for cottage level produc... more This paper reports on the design of fabrication and testing of a machine for cottage level production of pellets from cassava mash. The pelletizer consists of a barreled screw auger which compresses cassava mash against perforated end plate, through which the pellets are pelletized. The result derived from the calculated design parameters (shaft diameter, tensile stress, torque, screw length, volumetric capacity mass flow rate and power rating) were used for the fabrication. The testing of the pelletizer was determined in terms of throughput of the machine, against the moisture content of the mash (18, 20 and 22% w.b.), die size (4, 6 and 8 mm) and the auger speed (90, 100 and 120 rpm). Test results showed that the pellets with the best quality attributes were obtained from cassava mash at 18% moisture content (w.b.) through the 4 mm die at 90 rpm and a maximum throughput of 54 kg/h.
Engineering Science and Technology, an International Journal
The research models and simulates in-pipe turbine hydropower harnessing possibilities in water di... more The research models and simulates in-pipe turbine hydropower harnessing possibilities in water distribution networks of the sites under investigation considering in-pipe lift-based spherical turbine. The hydrofoil profile of the turbine is generated using National Advisory Committee for Aeronautics (NACA) aerofoil generator. Consequently, a Computer-Aided Design (CAD) model of the in-line lift-based spherical turbine is then developed and simulated, based on the peak and lean period of the vol-umetric discharge rates using commercial computational fluid dynamics software (Autodesk Simulation CFD Ò). The time series of power outputs are computed from the time series of discharge variations. A lift-based spherical turbine with NACA 0020 foil cross-section appears appropriate for extraction of energy in the water distribution pipelines. Furthermore, the minimum and maximum percentage head loss due to insertion of the turbine is about 1.94% at lean flow rates and 9.70% at the peaks for 250 mm pipelines. The available power was found out to depend on the density of the turbine blades material, flow rate, and the pipe diameter. The estimated lean and the peak electric power are about 415 and 1663 W, respectively, using aluminium foil blades while stainless steel foil produces about 242 and 1080 W in the 250 mm pipe. Ó 2018 Karabuk University. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. SUMMARY 1.0. Abstract It is proposed to explore the use of open distance learning modules in p... more 1. SUMMARY 1.0. Abstract It is proposed to explore the use of open distance learning modules in promoting skills acquisition in two vocational areas – motor vehicle repairs and building maintenance by artisans-in-training at the vocational enterprise institutions (VEIs) being set up by the Federal Ministry of Education and university undergraduates to be apprenticed to master artisans. The strategic objectives of the project are to develop and place on the project website ODL modules for promoting the acquisition of vocational skills, enhancing the theoretical knowledge of artisans in motor vehicle repairs and building maintenance through the provision of ODL instruction via video conferencing by university lecturers to vocational enterprise institutions in Osun and Oyo States and improving the practical skills of university undergraduates in mechanical engineering and civil engineering departments through apprenticeships to master artisans located in Osun and Oyo States with consta...
The development of an electromechanical device employing a novel single unit operation to agglome... more The development of an electromechanical device employing a novel single unit operation to agglomerate chocolate drink powder is reported. The machine admits cocoa powder and sugar granules into an electrically heated chamber, whereby a ribbon conveyor stirs and moves the mixture to the discharge chute. Optimal process conditions were: barrel temperature, 180oC; cocoa powder to sugar ratio, 1:4; and sugar particle sizes, 260 m and 360 μm.The experimental agglomerates had shorter reconstitution times, superior degrees of consolidation, the same range of bulk and tap densities, and similar sensory quality compared with some commercial (international) brands of chocolate beverage products. The machine provides a simple yet viable technology for agglomeration of chocolate drink powders