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Item DEVELOPMENT AND EVALUATION OF PINEAPPLE (Ananas comosus [L.] Merr.) POMACE BASED EXTRUDER(2014-03) ODUNTAN, OLUWAFEMI BABATUNDEIn large scale juice processing, about 65% of the pineapple is extracted as juice, while the remaining 35% is the by-product called pineapple pomace. Pomace generated from juice processing constitutes a disposal problem and environmental pollution and there is no processing equipment designed in addressing this problem through the utilisation of this byproduct. This study was designed to develop a mash extruder for pineapple pomace based flour. Pineapple pomace was analysed for its proximate composition using standard methods. Pomace flour was produced by drying and grinding fresh pomace from a juice processing plant. The physical and mechanical properties of the pineapple pomace flour using cassava flour as the binder were carried out by standard methods. An experimental laboratory press was used to evaluate the extrusion point pressure at different pineapple pomace/cassava flour ratio mash (5:1, 6:1 and 7:1), the moisture content of the mash (50, 55 and 60%), die size (4, 6 and 8 mm) and temperatures (60, 80, 100 and 120oC). Response Surface Method was employed to optimise the experimental data with extrusion point pressure as the response variable while temperature, moisture content, die size and pomace ratio were the independent variables. The results obtained were used to design and test a single screw pineapple pomace extruder. Operational power, compression ratio, throughput and efficiency of the extruder were determined using standard methods. Data were analysed using ANOVA. Pineapple pomace contained 12.4% moisture content, 4.8% ash, 1.4% fat, 9.2% crude protein, 6.0% crude fibre and 66.2% carbohydrate. The static angle of repose and coefficient of friction at various combinations of pomace and cassava flours increased linearly for the entire surface with moisture content and varied with structural surface in the moisture range of 12.4 to 26.3% (d.b). The minimum value of coefficient of friction for stainless iron steel was 0.44 for pineapple pomace based flour. The extrusion point pressure was 7.51 ± iv 0.62MPa, temperature, die sizes and pomace ratio significantly (p < 0.05) influenced extrusion point pressure. Optimum conditions for the extrusion point pressure were 100oC; 4.0 mm die size, 55.0% moisture content and 6:1 pomace ratio at maximum desirability of 1:00. The power required to operate the extruder was 4.0 kW at a compression ratio of 3:1. Machine throughput was 26.1 kg/h with the extruding efficiency of 87.9%. An efficient 4.0 kW pineapple pomace based extruder has been developed, which can be used to process and conserve pineapple pomace. Keywords: Pineapple pomace-flour, Extruder-development, Point-pressure. Word count: 400Item 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 CAUSES OF ROOF FAILURE AND MODELLING OF PITCHED ROOF BLOW -OFF IN SOUTHWESTERN NIGERIA(2011-08) ADESOGAN, SUNDAY OLUFEMIThe increasing incidences of roof failures especially blow-off in recent times in Southwestern Nigeria has become worrisome in view of the damage done to adjacent structures and danger posed to building occupants and owners. There is the urgent need to devise methods to curtail failures and minimize the incidences of blow-off. This study was designed to investigate the causes and patterns of roof failures, recommend curtailment measures and develop a model to predict roof blow-off. Using purposive sampling technique, a survey of 3,780 roofs spread across Ekiti (450), Lagos (450), Ondo (360), Ogun (570), Osun (780) and Oyo (1,170) states was undertaken to establish the causes and patterns of roof failure. During the survey, timber samples at the point of roof construction (780), and those from failed (2000) and unaffected roofs (1000) were collected for moisture content determination in accordance with American Standard for Testing Materials (ASTM) D442 while the common nails used in construction were subjected to corrosion test in accordance with ASTM 1977. The integrity of nail joints was tested in accordance with ASTM 1761. Physical measurements of attic space and ambient temperatures, roof slopes, building dimensions and orientation were taken and combined with topography and courtyard effect to develop aerodynamic model to predict roof blow-off. The model was validated using post-model survey captured data. Data were analysed using descriptive statistics and regression analysis. Causes of roof failures included poor workmanship (30.5%), materials inadequacies (18.6%), design errors (14.8%), roof geometry (14.0%), topographical location (11.8%), age and environment (10.3%). Timber‟s moisture contents were 12.0% to 24.0% during construction. Natural seasoning of these moisture contents to 7.0% in service, induced stresses on roof members. Temperature fluctuations between 20.0oC and 40.0oC promoted moisture condensation and dimensional changes in roofs‟ wooden members. Poorly fitted joints reduced joint load from 103.1 ± 8.3 kg to 82.6 ± 5.1 kg. Nail diameter reduced from 21 ± 0.2 mm to 14.7 ± 0.3 mm within 90 days of exposure to water indicating potential reduction in joint strength. Blow-off occurred when ≤ 0; where MR and MO are resisting and overturning moments respectively. The model revealed that while gable roof could be adequate at the plain, hip roof with pitch angle between 40o and 60o would be appropriate on 5o and 10o slope hills respectively, with coefficient of multiple regression of 0.91 (p < 0.05). The model also revealed that optimum UNIVERSITY OF IBADAN LIBRARY xviii pitch angle was 55o and presence of courtyard reduced the wake and drag effects on roof. There were no statistical differences between the roof blow-off model predictions and post model survey data. The overturning moments for the rest were also greater than the resisting moment but they did not experience blow-off because of adequate anchorage of the sill. Roof failures in Southwestern Nigeria were caused by weakened joints resulting from corroded nails, interface gaps and wind effect. Remedial measures could include appropriate building orientation, proper anchorage, high pitch and adequate openings. Keywords: Roof failure, Blow-off, Pitched Roof, Modeling, Southwestern Nigeria Word Count: 497 wordsItem Influence of Ageing on Selected Engineering Properties of Cassava [Manihot Esculenta (Crantz)] Roots(2014) Oriola, K. O.Postharvest processing of cassava roots is faced with problem of ineffective machines in Nigeria. Physiological changes associated with the common practice of leaving matured roots un harvested until when needed may affect their engineering properties which determine design parameters. Information on the engineering properties of cassava as affected by age, needed for appropriate machine design is scarce. This study was conducted to investigate the influence of ageing on some engineering properties of cassava roots. Three cassava varieties, TME 419, TMS 30572 and TME 7, were each harvested at 12, 15 and 18 Months After Planting (MAP). Root mass, length, diameter and peel thickness at the top, middle and bottom sections, Peel Proportion by Weight (PPW) and Moisture Content (MC) were determined. In addition, Coefficient of Friction (COF), Coefficient of Internal Friction (CIF), Coefficient of Rolling Resistance (CRR), and strength properties (stress, stiffness and toughness) were also determined at the ages. The COF and CRR were determined on Stainless Steel (SS), Galvanized Sheet (GS) and wood surfaces. All were done according to ASABE standards. Data were analyzed using descriptive statistics, regression and ANOVA at p = 0.05. Mass of TME 419 and TME 7 increased from 262.7±143.4 and 229.9±147.0 to 483.5±245.2 and 489.1±274.3 g between 12 and 18 MAP respectively, while TMS 30572 reduced after 15 MAP. Length and diameters of TME 419 and TMS 30572 reduced after 15 MAP while peel thicknesses increased with age. The TME 419 produced lowest PPW at 12 MAP and highest at 15 MAP while the moisture contents of roots ranged from 70.0% to 74.0% (wet basis). The COF of TMS 30572 across ages (12 to 18 MAP) ranged from 0.16 to 0.29, 0.42 to 0.53 and 0.61 to 0.79 on SS, GS and wood respectively. The TME 419 and TME 7 had the least COF on GS and wood at 15 MAP. The CIF peaked at 15 MAP for all the varieties. On all the surfaces, CRR peaked at 15 MAP for TMS 30572, decreased for TME 419, and decreased on SS and wood surfaces for TME 7, at this same age. The CIF decreased while COF increased with increase in MC. Age and MC significantly affected COF and CIF while peel significantly affected CRR. High COF on wood suggested high angle of inclination in wooden container design and storage structures. Low CRR implied that the roots would not slide but roll on all the surfaces. Peak stress, stiffness and toughness ranged from 0.41 to 1.30 N/mm2, 3.22 to 9.28 N/mm2 and 3.23 to 9.82 N.m respectively across ages and increased with increase in MC showing that roots require low power during processing. Influences of age and MC on the strength properties of TMS 30572 were not significant whereas TME 419 strength properties depended on age. Neither age nor MC significantly influenced the strength properties of TME 7. Root age and variety strongly influenced the engineering properties of cassava roots. Machine designers therefore need to take into consideration the properties of cassava roots across ages and variety for effective mechanical processing operationsItem Utilization of oil palm wastes in south western Nigeria(The Nigeiran Society of Engineers, 2003) Mijinyawa, Y.; Ogunbanjo, O. I.A survey involving the use of questionnaires and personal communication during field visits was undertaken in Ekiti, Ogun, Ondo, Osun and Oyo states of Nigeria to ascertain the level of utilization of the inedible portions of oil palm products often referred to as wastes. Items identified as wastes and their present uses include trunk for bridges and roof trusses; fronds and leaves for brooms, thatching of roofs and fences, staking of creeping and climbing plants, weavmg of baskets and cages and cordage materials; fruit bunches for black soap production; kernel shells for soil erosion control and furnace fuel; and mill effluents for sludge cake used as fuel, A substantial amount of these wastes are unutilized which has resulted in their constituting nuisance in plantations and mill sites. Incineration is the only disposal method employed to create space for other activities. It is recommended that the use of these wastes be popularized among urban dwellers to create market for them. Fruit harvesting and conversion of the trunk are tedious; hence the development of appropriate technology for improved efficiency required.Item The influence of post-cracked exposure period on some physical properties of palm kernel shells(The Nigeiran Society of Engineers, 2000) Mijinyawa, Y.; Falayi, F. R.A series of experiments were conducted to measure the influence of the duration of exposure to inclement weather after cracking on the bulk density, solid or true density, porosity, and water absorption characteristics of palm kernel shells (PKS). The results showed that the bulk and true densities decreased respectively from 0.60g/cm3 and 1.37g/cm3 for freshly cracked shells to 0.53g/cm3 and 1.25g/cm3 for shells that have been exposed to inclement weather for over ten years after cracking. The porosity and ability to hold moisture increased with the duration of exposure. These experimental observations are attributable to the organic nature of the shells as a result of which there is a gradual biodeterioration especially of the adhering fibers. This reduces the dry matter content and increase the void. Density values obtained are comparable with other materials of construction such as earth and wood which is an indication that PKS has potentials for use as a material for construction. Further work on the mechanical properties of the material is recommended.Item Farm structures and environment: The indispensable but unappreciated specialization of agricultural engineering in Nigeria.(The Nigeiran Society of Engineers, 2011) Mijinyawa, Y.Farm structures, a vital component of agricultural engineering is given very little recognition because of conflicts and ignorance. Neglected in terms of man power and facilities, its numerous potentials for agricultural development remain untapped. Climate change and noise from increasing farm mechanization activities are becoming threats to agricultural practice and a challenge to the farm structures experts. To appropriately respond to these challenges, due attention need to be given to the theory and practice of the profession while collaboration and information exchange among the experts need to be strengthened.Item Coefficient of static friction of palm kernel shell on selected structural surfaces(The Nigeiran Society of Engineers, 2000) Mijinyawa, Y.; Falayi, F. R.An experiment was conducted to measure the static coefficient of friction of palm kernel shell (PKS) on plywood, galvanized iron and glass. The results of the test showed that the coefficient of static friction of PKS increases with moisture content irrespective of the surface employed. The .values of coefficient of static friction obtained varied from 0.42 to 0.75 on plywood, 0.34 to 0.62 on galvanized iron and 0.32 to 0.56 on glass for moisture contents ranging from bone dry to 18.4% wet basis. This implies that PKS is most resistant to flow on plywood and least on glass. A statistical analysis showed that these variations with structural surfaces were Significant. Further similar work using the cracked palm kernel is recommended.Item Farm structures and rural electrification palm kernel shells as coarse aggregates for light weight concrete(The Nigeiran Society of Engineers, 1999) Mijinyawa, Y.; Okedoku, O. W.The escalating cost of conventional building material has given rise to the need to source for alternative ones. In souring for such alternatives, the durability, availability and cost of the potential material should be considered. Palm kernel shell (PKS), a by-product in the process of palm kernel oil extraction found in abundance in southern and grossly underutilized was considered of potential as a coarse aggregate for light weight concrete. In order to confirm the assumed potential, it was considered necessary to determine the density and compressive strength of concrete cubes manufactured from PKS. Coarse aggregates made us of crushed granite and PKS mixed in varied proportions were used to cast 150mm x 150 mm concrete cubes of 1: 3: 6 mix batch by weight. The cubes were removed from moulds 24hr after casting and immersed in water for seven days to cure. The density and compressive strength of the cubes were then decreased. Expectedly, the density and crushing strength of cubes decreased with increase in the amount of PKS in the cubes but the density range of 1520 to 2234kg/m3 and strength values of 0.44 to 3. 89N/mm2 obtained were good enough for light weight concrete. PKS has great potential as a material for coarse aggregate in concrete work; the use of which could considerably reduce the construction cost of building and promote environmental sanitation.Item Determination of some physical properties of palm kernel(The Nigeiran Society of Engineers, 2005) Mijinyawa, Y.; Omoikhoje, S.Experiments were carried out to determine the dimensions of palm kernel, the shell thickness, kernel and nut densities as useful parameters in its handling and processing. The major, intermediate and minor diameters of the kernel were found to vary from 26.5 to 44, 21.5 to 34.5 and 16.5 to 28mm respectively. Sphericity was calculated to be between 76 and 80 and was independent of the size of the kernel. Nut densities varied from 0.8 to 2g/cm3 while kernel densities varied from 0.93 to 1.33g/cm3. The nut densities were generally higher than the kernel densities and the variation is attributed to the large volume but lightweight of the shell. The shell thickness varied from 2 to 6.5mm. These parameters are useful in the design of handling and processing equipment for palm kernel