Scholarly works in Agricultural and Environmental Engineering
Permanent URI for this collectionhttps://repository.ui.edu.ng/handle/123456789/568
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Item Physical Characterisation of Two Varieties of Bambara Groundnut Seeds(Adeleke University, 2022) Aremu, A. K.; Ojo-Ariyo, A. M.; Oyefeso, B. O.Some physical attributes of two selected varieties of Bambara groundnut seeds grown in Nigeria were determined in this study. Standard methods were used to determine the selected properties which include linear dimensions, surface area, mass, volume, density, sphericity, porosity and coefficients of friction of the seeds on plywood, galvanized iron and aluminium surfaces. Length, width and thickness were within the ranges of 13.41-14.40 mm, 12.00-12.89 mm and 11.36- 11.99 mm, respectively for cream variety and 12.54-13.91 mm, 11.16-12.28 mm and 10.51-11.46 mm, respectively for light brown variety. Surface area of the seeds and volume were within the ranges of 507.94-588.45 mm2 and 1077.59-1351.79 mm3, respectively for cream variety, and 443.05-880.63 mm2 and 541.47-1191.18 mm3, respectively for light brown variety. The thousand seed mass ranged from 833.20 to 1116.93 g and 718.97 to 863.83 g for cream and light brown varieties respectively. Bulk density ranged from 0.71 to 0.79 g/cm3 and 0.71 to 0.77 g/cm3 for cream and light brown varieties respectively. The results showed that that the cream variety is larger and heavier than the light brown. Variations in true density and porosity of the seeds were sinusoidal in nature as moisture content increased for both varieties. Frictional coefficients on the three surfaces increased with moisture content. The investigated physical attributes were dependent on the amount of moisture in the seeds. The results from this study are useful in the development of handling and processing equipment for Bambara groundnut seeds.Item Selected mechanical properties of Banbara groundnut seeds under compressive loading(LAUTECH, 2022) Aremu, A. K.; Ojo-Ariyo, A. M.; Oyefeso, B. O.Knowledge of mechanical properties of agricultural materials is useful in the development of equipment for processing and handling them.Selected mechanical propertiesnamely rupture force, maximum deformation at rupture point, hardness and toughness of cream and light brown varieties of Bambara groundnut (BGN) seeds were determined at four moisture levels (5, 15, 25 and 35% dry basis) under compressive loading alongaxial and longitudinal orientations.Rupture force, deformation, hardness and toughness of BGN seedswere within the ranges 45.58-438.55 N, 0.31-5.71 mm,14.61-448.55 Nmm-1 and0.01-1.02J, respectively. Rupture force, deformation and toughnessof the seeds had interplay of increasing and deceasing trends while hardness decreased consistently as moisture content increased from 5% to 35%.The cream variety withstood higher rupture force and deformed more without failure than the light brown variety within moisture content range of 5-25% along both loading orientations.Bothvarieties demonstrated greater hardness when loaded along the longitudinal orientations than the axially loaded samples. All the investigatedproperties were dependent on moisture content andorientationof loading. Predictive mathematical models forestimating the investigated properties at different moisture contents with reasonable accuracy were also established in this study.Item Design, construction and performance evaluation of a rice destoner(CIGR, 2018) Aremu, A. K.; Oyefeso, B. O.; Ajao, T. O.; Ojo, K.; Egbunu, J. O.The market price of local rice in the market is significantly determined by its quality which is dependent on the level of cleaning and some other processing operations. Hence, the need to improve the quality of rice, increase production and reduce human labour has brought about the development of rice destoning machine. Therefore, this study aimed at designing, fabricating and evaluating the performance of a rice destoner. The design was based on the principle of material separation and was constructed from locally-available materials. The machine was powered by a 2hp electric motor and three vibrating screens of varying apertures were used for the upper, middle and lower screens. The machine had an average capacity of 130 kg/h. The performance of the machine was evaluated with 10 kg of Ofada rice at 11, 21 and 25% moisture content (dry basis) and 10 kg of Faro 55 rice at 14, 22 and 27% moisture content (dry basis). The results showed that separation efficiency decreased as the moisture content of rice decreased for both varieties. Cleaning of rice at low moisture content is recommended for optimum performance of the destoner.Item COMPARATIVE EVALUATION OF NOVEL LOW-COST MOISTURE METERS SUITABLE FOR GRAIN MOISTURE MEASUREMENT(Department of Zoology, University of Ibadan, Nigeria, 2013) Ajao S.K.Monitoring grain quality is an importa. * postharvest activity which starts at harvest, continuing during stcage and up to the point of sale. High moisture in stored maize can be detrimental to food safety because of the likelihood of aflatoxin contamination and other forms of deterioration. Moisture meters are devices which provide real-time access to measuring moisture levels thereby allowing farmers .' m eet grain quality requirements. A newly developed low- co ^ moisture meter known as the Post-Harvest Loss (PHL) moisture meter is a device with potentials for massive deployment among smallholder farmers. This study was therefore set up to compare the efficiencies of some existing moisture meters co m’ ared with this newly developed device. Two commercially available moisture meters — Dickey john GAC 2100 and John Deere me ters were compared with the PHL moisture meter and oven- dried method (ASABE standards) used as control. Maize grains from a bagged storage experiment were used as samples over a 12- month period. Results showed that the moisture meters had a positive difference of <3% MCwb relative to oven-dried method. Average measurements showed variances of 2.34, 1.08 and 0.56% MCwb for John Deere, PHL and GAC 2100 meters respectively, when compared with the oven-dried method. Thus, it was concluded that the low cost PHL moisture meter may serve as an effective alternative to the more expensive types and may be relatively easy to adopt for laboratory and field use among smallholder farmers in sub-Saharan Africa.Item OPTICAL PROPERTIES OF TIGERNUT (CYPERUS ESCULENTUS) AS INFLUENCED BY MOISTURE CONTENT AND WAVELENGTH(Department of Agricultural Engineering, Faculty of Technology, University of Ibadan, Ibadan, Oyo state, 2016) omale A.Tigemut (Cyperus esculentus) is one among the underutilized crops in Nigeria despite its high economic value. This study investigated the absorbance, transmittance and colour of yellow tigernut as influenced by moisture content at 8%, 16%, 24%, 32% and 42% (db) respectively. The tigernut samples were collected directly from a farm in Minna, Niger state and cleane d to remove all foreign materials, initial moisture content w, ’ determined using ASAE standard after which samples were conditioned to the desired moisture levels following standard method. Using a spectrophotometer, the absorbance ranged from 3.04 to 6.35 and transmittance ranged from 0.00 to 0.19 within a wavelength range of 320nm to 720nn. while he colour using a Chroma meter ranged from 3.73 to 4.14, 5.19 to 8.18 and 13.1 to 19.0 for L (brightness), a (red) and b (yellow) respectively. ANOVA also revealed that moisture has significant effect at p<0.05 on abs, 'bance, transmittance and colour of the tigernut. Correlation and regression analysis revealed a positive linear relationship between all moisture contents with absorbance, transmittance and colour.Item UNIVERSITY OF IBADAN LIBRARY i INFLUENCE OF MOISTURE ON SOME ENGINEERING PROPERTIES OF BUSH MANGO SPECIES’ [Irvingia gabonensis AND Irvingia wombolu (HOOK, F.)] SEED AND KERNEL(2015-03) IKOTUN, Taibat OlusolaIrvingia gabonensis and Irvingia wombolu are species of bush mango commonly found in Africa whose kernel are processed into soup. Literature generally abounds on the nutritional composition of the fruits and kernel but there is dearth of information on the engineering properties which are very important in the design of processing equipment and machines. This study was designed to investigate the influence of moisture on some engineering properties of seeds and kernels of I. gabonensis and I. wombolu. Irvingia gabonensis sourced from Oyo, Ogun, Osun and Irvingia wombolu sourced from Edo, Ondo and Imo states, Nigeria were used for the study. Based on moisture content at harvest and storage, their seeds were conditioned to moisture content of 10.0%, 20.0%, 30.0%, 40.0% and 50.0% and kernel to 2.2%, 3.7% and 5.3% (dry basis) using ASABE method. Properties studied include dimension, sphericity, true and bulk densities, porosity and angle of repose on commonly used material such as plywood, glass and steel for seed and kernel. Deformation, rupture force, failure stress, stiffness and Young’s moduli for seed were determined. Specific heat, thermal conductivity and diffussivity of kernel were studied. All properties were evaluated using ASABE standards and data analysed using ANOVA at p = 0.05. Kernel length, width, thickness and sphericity increased respectively from 25.9 to 30.4 mm, 15.7 to 19.2 mm, 3.5 to 4.3 mm and 43.3 to 44.6% with increase in moisture content. Length and width of seed decreased from 53.5 to 34.7 mm and 38.4 to 30.3 mm respectively with increase in moisture content while, thickness and sphericity increased from 3.5 to 4.2 mm and 66.7 to 78.0% respectively, indicating that seeds swell only in the lateral direction. Sphericity of seed was high indicating tendency to roll easily while low sphericity of kernel indicates sliding on structural surfaces. True density increased from 825.6 to 1216.4 kgm-3 and 697.7 to 1092.0 kgm-3 for seed, and kernel respectively. Their densities appear close to that of water hence may be difficult separating them using water. Angle of repose increased from 30.4 to 52.9o and 18.9 to 29.0o for seed and kernel respectively and was significantly affected by moisture content and species. Based on existing design, hopper and inclined discharge chute can be used for seed and flat bed for kernel. Deformation and Young’s modulus increased linearly from 1.4 to 3.9 mm and UNIVERSITY OF IBADAN LIBRARY iii 5978.0 to 26098.0 Nmm-2 respectively for seed and were significantly affected by moisture and species. Specific heat and thermal conductivity of the two species increased with moisture and those of I. wombolu (982.8 JkgK-1, 0.2 Wm-1K-1) were significantly higher than I. gabonensis (795.9 JkgK-1, 0.1 Wm-1K-1) kernel. Thermal diffussivity also increased with moisture content and was significantly higher in I. wombolu than I. gabonensis; hence I. wombolu kernels will dry faster. Mechanical properties of the seeds evaluated at the selected moisture content showed that more energy would be required in cracking of Irvingia wombolu during kernel extraction than the same quantity of Irvingia gabonensis at the same processing condition. Keywords: Bush mango, Moisture content, Engineering properties Word count: 498Item INFLUENCE OF MOISTURE ON SOME ENGINEERING PROPERTIES OF BUSH MANGO SPECIES’ [Irvingia gabonensis AND Irvingia wombolu (HOOK, F.)] SEED AND KERNEL(2015-03) IKOTUN, T. O.Irvingia gabonensis and Irvingia wombolu are species of bush mango commonly found in Africa whose kernel are processed into soup. Literature generally abounds on the nutritional composition of the fruits and kernel but there is dearth of information on the engineering properties which are very important in the design of processing equipment and machines. This study was designed to investigate the influence of moisture on some engineering properties of seeds and kernels of I. gabonensis and I. wombolu. Irvingia gabonensis sourced from Oyo, Ogun, Osun and Irvingia wombolu sourced from Edo, Ondo and Imo states, Nigeria were used for the study. Based on moisture content at harvest and storage, their seeds were conditioned to moisture content of 10.0%, 20.0%, 30.0%, 40.0% and 50.0% and kernel to 2.2%, 3.7% and 5.3% (dry basis) using ASABE method.Properties studied include dimension, sphericity, true and bulk densities, porosity and angle of repose on commonly used material such as plywood, glass and steel for seed and kernel. Deformation, rupture force, failure stress, stiffness and Young’s moduli for seed were determined. Specific heat, thermal conductivity and diffussivity of kernel were studied. All properties were evaluated using ASABE standards and data analysed using ANOVA at p = 0.05. Kernel length, width, thickness and sphericity increased respectively from 25.9 to 30.4 mm, 15.7 to 19.2 mm, 3.5 to 4.3 mm and 43.3 to 44.6% with increase in moisture content. Length and width of seed decreased from 53.5 to 34.7 mm and 38.4 to 30.3 mm respectively with increase in moisture content while, thickness and sphericity increased from 3.5 to 4.2 mm and 66.7 to 78.0% respectively, indicating that seeds swell only in the lateral direction. Sphericity of seed was high indicating tendency to roll easily while low sphericity of kernel indicates sliding on structural surfaces. True density increased from 825.6 to 1216.4 kgm-3 and 697.7 to 1092.0 kgm-3 for seed, and kernel respectively. Their densities appear close to that of water hence may be difficult separating them using water. Angle of repose increased from 30.4 to 52.9o and 18.9 to 29.0o for seed and kernel respectively and was significantly affected by moisture content and species. Based on existing design, hopper and inclined discharge chute can be used for seed and flat bed for kernel. Deformation and Young’s modulus increased linearly from 1.4 to 3.9 mm and 5978.0 to 26098.0 Nmm-2 respectively for seed and were significantly affected by moisture and species. Specific heat and thermal conductivity of the two species increased with moisture and those of I. wombolu (982.8 JkgK-1, 0.2 Wm-1K-1) were significantly higher than I. gabonensis (795.9 JkgK-1, 0.1 Wm-1K-1) kernel. Thermal diffussivity also increased with moisture content and was significantly higher in I. wombolu than I.gabonensis; hence I. wombolu kernels will dry faster. Mechanical properties of the seeds evaluated at the selected moisture content showed that more energy would be required in cracking of Irvingiawombolu during kernel extraction than the same quantity of Irvingia gabonensis at the same processing condition.