AGRICULTURAL & ENVIRONMENTAL ENGINEERING
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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 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 Suitability of chrysophyllum albidum wood for fabrication of howe truss for use in simple roof systems(Forestry Association of Nigeria, 2010) Adewole, N. A.; Baruwa, M. A.Chrysophyllum albidum being fruit tree still has dearth of information about its wood properties. Its use for making roof truss components have become fashionable in low cost building in emerging areas of Akinyele Local Government, Ibadan, Oyo State, Nigeria because of its abundance. This study was initiated to investigate the suitability of C. albidum wood for Howe truss fabrication. A survey was conducted to obtain on the application status of C. albidum wood in the study location. Structured questionnaire, oral interview and on-spot assessment were used to collect data while simple descriptive statistical tools were used for the data analysis. 10-meter-span Howe-truss was designed but scaled down to 2-meter for prototype production. Six prototypes were fabricated using C. albidum wood bought from a plank market in the area. The deflection characteristics of the fabricated truss was investigated under three points loading system using dial-gauge. Modified Howe truss was predominantly used in low cost building in the emerging areas of Akinyele Local Government that were hitherto villages. About 90.1% of such houses combined C. albidum wood with other available wood species to make its roof trusses. C. albidum wood was relevant for its availability and cost. The gusset plate made from 6.5mm structurally graded plywood was used at the joint with 8d nail as fastener. The fabricated Howe truss weighs 1.2KN. A load of 2.2KN (about triple of the design load) was only able to cause maximum of 3.3mm deflection as against maximum tolerable deflection of 6.6mm. The test result indicates suitability of C. albidum wood for Howe truss production despite it been perishable when used in contact with soil.Item Production of Bamboo-Lam from bamboo strip prepared from Bambasa Vulgaris Schrad(Material Science and Technology Society of Nigeria, 2011) Adewole, N. A.; Olayiwola, H. O."This study addressed the problem of producing bamboo-lam from flat strips prepared from Bambusa vulgaris Schrad. Such bamboo-lam is suitable for making bamboo-based products for interior use. Bambusa vulgaris samples were sourced from 4 years old stock, at the same time of harvest, from within the University of Ibadan, Oyo State, Nigeria. The harvested matured culms were reduced to 780mm long each with a minimum diameter and wall thickness of 30mm and 5mm respectively. The short culms were split, rough planed to remove nodal protrusion and green epidermal layer before soaked in hydrogen peroxide treated hot water for 24 hours to improve strips resilence to insect and fungal attack. The dried strips were dressed, glued, cured and finished to produce bamboo-lam. For the flat bamboo strips produced, the percentage recovery index (RI) after splitting was 75% and reduced to between 50-57% after surface planed. Untreated strip was prone to attack while soaking in hot hydrogen peroxide treated water for 24 hours-improved their resilience to degradation and insect attack. The dimensions, percentage RI and durability of strips produced from Bambusa vulgaris thus depend on its culm features, handling skill, equipment and treatment. Bamboo laminates of width 25 x (5-8)mm were produced from the flat bamboo strips produced. This study has been able to produce durable bamboo strips and laminates from Bambusa vulgaris Schrad using common carpentry tools and machines. The bamboo-lam produced is suitable for manufacturing bamboo-based products for interior use. "Item Assessment of Kwara state tractor hiring unit(The Nigerian institution of Agricultural Engineers, 2010) Mijinyawa, Y.; Adebayo, S.A survey was undertaken to assess the Kwara State Tractor Hiring Unit using fleet of equipment, personnel and workshop facilities, and its impact on the farming populace in the state as assessment criteria. The study adopted the use of a questionnaire and interview schedules, focused group discussion and personal observation for data collection. Records available at the headquarters of the unit provided additional source of information. The unit has a total of 38 tractors which comprises of 29 Ursus 5312, six New Holland 5635, three heavy duty tractors, 22 disc ploughs, seven mouldboard ploughs, 18 disc harrows, eight disc ridgers, 10 trailers, two rice shellers, five multipurpose shellers, two maize shellers and one fourwheel drive jeep car. Majority (81%) of the equipment were functional, a few (13%) required minor repairs to be used on the farm and 6% were scraps. The unit has neither a workshop nor an implement shed thus exposing the machinery to inclement weather. Personnel in the unit are adequate but the maintenance culture is service driven. There has been a general increase in farm sizes since the introduction of the unit even though only a few farmers have been able to access the services rendered by the unit. Several reasons accounted for the limited beneficiaries from the activities of the unit prominent among which are inability to raise the cost of hiring, delay in service delivery, remoteness of farms and small holdings.The unit has great potentials for improving the agricultural productivity of the state if the equipment available can be effectively utilized. Towards achieving this, it is recommended that a functional workshop and implement sheds be provided at the headquarters and area offices, the activities should be decentralized while adopting a regular maintenance culture. As an agency of the government, there should be adequate funding by the state government.Item Analysis of climatic factors for the selection of greenhouse glazing materials in Ilorin, Nigeria(The Nigerian institution of Agricultural Engineers, 2011) Mijinyawa, Y.; Ajayi, S. A.The effect of climate change in recent times has necessitated the need for a controlled environment for the cultivation of many crops which were hitherto cultivated under natural tropical condition. An appropriate method of accomplishing this is through the use of greenhouses which modify the environment to produce a micro-climate suitable for optimum plant growth. The successful use of greenhouses depends on the choice of appropriate glazing material. Tomatoes are precious crop demanded all year round but the production of which is being reduced by the effect of climate change. Desirous to increase the level of production, the study attempts to identify appropriate glazing material for greenhouse: for the production of tomatoes in Ilorin, Nigeria. Climatological data were collected from the Ilorin International Airport and analyzed in order to identify appropriate - covering materials for the development of greenhouse structures in Ilorin. Double layer polyethylene and white corrugated polyvinylchloride were the two glazing materials that have the lowest inner surface temperatures arid also satisfy the condition of heat load. To derive the maximum benefits of greenhouses, in addition to using these materials, Proper ventilation and shading of the greenhouses are recommended.Item Preliminary investigation of emission characteristics of shaving from three wood species utilized for furniture production in Ibadan, Oyo State(International Commission of Agricultural and Biosystems Engineering, 2012) Adewole, N. A.; Oyewola, M. O.; Salau, T. A. O.; Bello, R. O.; Raji, T. O.Carpentry workshop is among the prominent and active components of the Nigerian wood industrial sector. The activity in carpentry workshop inevitably generates different categories of wastes. Shavings is among the wood wastes generated in large quantity and the common means of disposing it in major town like Ibadan in Oyo State is by combusting. Large percentage often finds its way to household where it's often used to subsidize fuel for domestic cooking. However, this means of disposal may be prone to health hazard due to the emission released during its combustion. This work examines the combustion characteristics of three typical wood species that are commonly use for furniture production in Ibadan, Oyo state. The species were combusted in Bubbling Fluidized Bed (BFB) combustion under various operating conditions. The result shows that Carbon monoxide (CO) emission is pronounced in the combustion of all the wood species. In all the three cases, Milicia excelsa (Iroko) and Tectona grandis (Teak) have the lowest and highest CO emission respectively. It is suggested that if this waste must be used as fuel for domestic cooking, appropriate technology must be employed especially where low combustion temperature is desirable. However, proper disposition of this waste should be encouraged.