scholarly works

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Classification and evaluation of crop storage structures in Western Nigeria
(The Nigerian Society of Engineers, 1993-12) Mijinyawa, Y.
A survey involving the use of questionnaires and personal communication during field trips was carried out in Western Nigeria with the aim of classifying and assessing the efficiency of the existing structures for the storage of crops. Barns; cribs; trenches; platforms; warehouses and silos are among the important Storage structures. The existing structures could be efficient with proper management but a major limitation of most of them is the low unit capacity which is inadequate to cope with the present volume of agricultural production. Research efforts should concentrate more on improving the existing structures rather than their replacement.
The design, construction and testing of a wooden silo for grain storage
(The Nigerian Society of Engineers, 1996-03) Lucas, E. B.; Mijinyawa, Y.
A hexagonal, double-walled, wooden silo of sides 1.2m, height 1.8m and of 7m3 capacity was designed. The walls and floor were taken as stressed skin panels. These were fabricated using Mansonia altissima for the ribs, while exterior grade structural plywood was used as sheathing. The silo was subjected to nondestructive testing in accordance with the British Standard Code of Practice CP: 112 and joints separation, consolidation movement of the foundation and floor deflection were periodically measured over a period of two weeks during which the structure was under load. At the end of the test period there was no measurable consolidation movement and the joints remained intact while the floor deflection was within permissible limit of ∆ ≤ L/180. Further testing and evaluation including subjecting the silo to loading for longer duration and taking measurements of stresses induced on the silo components are to be undertaken.
Problems and prospects of metal silos for grain storage in Western Nigeria
(The Nigerian Society of Engineers, 1997-06) Mijinyawa, Y.
A survey involving the use of structured questionnaires and personal communication was carried out in Western Nigeria to ascertain the type and extent of use of silos for the storage of grains. Steel and Aluminium were found to be the predominant materials used for the construction of the silos. They are mainly used to store shelled corn and in a few instances, rice, cowpea and soybean. The prohibitive cost of silo acquisition limits their ownership and use to the Ministries of Agriculture, Co-operative Societies, agro-based industries, Teaching and Research Institutes and a few large scale private farms. Silos are not used by the small to medium scale farms. The withdrawal of the Ministries of Agriculture from direct grain production and the collapse of co-operative grain storage programmes have resulted in the abandonment of many silos. The metal silos experience the problem of moisture condensation on the roofs and walls which leads to the deterioration of stored grains through moulding, caking and rapid multiplication of insects. Losses of as much as 10% of total storage through these sources have been recorded for some silos. Adequate funding of current research efforts to develop local materials for grain silo construction is recommended.
The use of local building materials for the construction of farm structures in western Nigeria
(The Nigerian Society of Engineers, 1997-09) Mijinyawa, Y.; Dahunsi, D.
A Survey of the pattern of usage of building materials in the small - to - medium farms in Western Nigeria was undertaken. Wood was the commonest construction material in use, followed by earth products and natural fibers. Decay and weathering of natural fibers including timber; arid the erosion of earth products were the major problems experienced with their uses. Treatment of the natural products before use was found wanting. Adequate seasoning and preservative treatment of natural fibers’ and earth stabilization are recommended for durability. Cost is a vital consideration in the choice of construction materials for farm structures. The choice of local materials goes some way to reduce cost. Numerous improvements on performances of some local materials have been devised in the Research Institutes. There is a need for effective extension linkage between the research institutions and the farmers.
Comparative studies of temperature fluctuations within wooden and steel silos in Ibadan
(The Nigerian Society of Engineers, 1997-12) Lucas, E. B.; Mijinyawa, Y.
Temperature fluctuations and moisture condensation within the interiors of a steel and wooden silos were determined experimentally. The steel silo is of 1mm thickness while the wooden silo is a two-layered wall panel of 12mm and 6mm thick plywood separated by 50mm air-gap. Measurements taken during the hotter months of March and April in Ibadan showed that temperature fluctuations in the steel and wooden silos were 9°C and 7°C respectively. Corresponding maximum temperature in the silos were 38.5°C and 37.2°C. While the interior of the wooden silo remained dry, the steel silo had condensed moisture droplets lining its inner walls. Since moisture condensation in a silo contributes to grain spoilage by biological agents, wooden silos are rated superior in respect of reducing this adverse feature.
A survey of livestock structures in south western Nigeria
(Research Communications, 1998) Mijinyawa, Y.
A survey involving the use of structured questionnaires and personal communication was undertaken in South Western Nigeria to identify the livestock in the area, and their housing methods. Chicken, pigs, rabbits, goats, sheep and cattle were the major animals found while the housing structures include baskets, battery cages, deep litter houses, cages, hutches, pens, sheds and yards. In about half of the sites surveyed animals kept were not provided with housing, while in the other places where they were provided the structures were poorly equipped and overstretched to cope with the population of animals kept. Wood products are the predominant materials of construction accounting for as much as 50 to 70% of the total volume of materials used in the construction of some of these structures. Others are natural fibers, concrete, wire mesh and corrugated roofing sheets. Poor waste management, decay in wood members, and pitting and cracking of concrete were some of the flaws identified. Integrated designs to reduce the burden of waste collection and increase its effective utilization, use of durable timber species and preservative treatment to further improve the length of service, and the use of good quality concrete constituents and mixture are recommended.
The development and evaluation of a flat-type wooden incubator
(School of Agriculture and Agricultural Technology (SAAT), Federal University of Technology, Akure, 1998) Ewemoje, T. A.; Olorunnisola, A. O.
"A flat-type, 60-egg capacity incubator was designed, constructed and tested. The incubator differs from existing designs in that the cabinet was made from a 3-ply, 4mm thick interior grade plywood to reduce cost and at the same time enhance heat insulation. Also, two domestic kerosene lanterns were provided to supplement heat generation by three 40 W electric bulbs during electricity outages as commonly experienced in Nigeria.When tested with 30 eggs of a commonly sold chicken breed, incubated at average temperature of 38° C and relatively humidity of 58%, the chicks were hatched within 20 days. Relatively high percentages of fertility and hatchability of 86.2% and 76% respectively, as well as a relatively low chick mortality rate of 18.5% were recorded. "
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.
Wood products for grain silo construction in Nigeria
(Research Communications, 1999) Mijinyawa, Y.
Metal silos used for the storage of grains under warm humid climate experience the problem of moisture condensation on the roofs and walls, and its redistribution within the grain bulk results in the deterioration of the stored grains. This is occasioned by the high thermal conductivity of the material of construction which offers very little resistance to the flow of solar heat into the silo enclosure. Experimentation with various grades of rubber as material for silo construction proved unsuccessful while little success was recorded with the use of various forms of concrete construction as the incidence of moisture condensation was still noticed, Wood products are tested as materials for silo construction aimed at reducing the temperature fluctuations and moisture condensation within the silo. Results show that the material has the potential of significantly reducing the temperature fluctuations within the silo and eliminating moisture condensation on the silo walls when compared to metal type. The use of local materials of construction will reduce the cost of the silo, while the simple construction and maintenance technologies, and the possibility of small unit capacity renders it of advantage to the Nigerian small-scale farmers. Mass production to reduce cost to what can be accommodated by small scale farmers is recommended.
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.
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.
Determination of discharge coefficient of rectangular side weirs
(2001) Ogedengbe, K; Ewemoje, T. A.
The characteristics of flow over side weirs are taken into consideration to verify the discharge coefficient for suberitical flow conditions under the assumption of constant- specific energy. The main channel discharge, length of weir crest and sill height of the weir are treated as controlled variables. The discharge coefficient Cd is found to depend on the upstream Froude No F1 and also on the ratio of sill height to upstream flow depth S/Y1. Simple linear regression analysis was conducted to establish the relationship of Cd with both F1 and S/Y1 taken separately while multiple regression analysis was conducted to establish the relationship of Cd with both F1 and S/Y1 taken together. Cd decreases with increase in F1 while Cd increases with increase in S/Y1 ratio when taken separately. When taken together, it was clearly evident that variation in Cd was largely due to S/Y1 ratio while the effect of F1 was relatively negligible.
Assessment of tractor hiring services in Lagos State
(The Nigerian Society of Engineers, 2001) Akinoso, R.; Mijinyawa, Y.
Various agricultural mechanization techniques have been introduced to aid crop production. One of such is intensive use of tractors. Expensive capital and maintenance costs have limited the private ownership of tractors by Nigerian farmers. To promote the use and availability of tractors for farmers, tractor-hiring units were established. Tractor hiring units rent out tractors and other farm implements to farmers at affordable prices. Contrary to expectation, the aim of the program had been defeated due to technical laxity, poor management and the current economic situation of the country. Recognizing the necessity of tractor hiring units, efforts are made on ways of improving performances. Good organization and proper management are needed for effective operation.
Trial Production and Testing of cement-bonded particles board from rattan furniture waste
(Society of Wood Science and Technology, 2002) Olorunnisola, A. O.; Adefisan, O. O.
An investigation was conducted on the use of rattan (cane) furniture waste as furnish material for the manufacture of cement-bonded particleboard (CBP). Laboratory scale CBPs were fabricated from hot water pretreated chopped strands of mixed rattan waste obtained from rattan furniture workers in Ibadan, Oyo State, Nigeria. Three-layered boards of 6-mm thickness were made comprising coarse core and tine surfaces at two density levels of 1,050 kg/mi and 1,200 kg/m3, three CaCl2 concentration levels of: 2.5%, 3.0% and 3.5% and using Portland cement-cane mixing ratios of 2.5:l .0, 2.75: 1 .0, 3.0: 1 .0, and 3.25: 1 .0. After board manufacture, ASTM D 1037 (1998) test procedures were employed to obtain strength and moisture absorption properties. Average properties for bending modulus of rupture (MOR) and modulus of elasticity (MOE) of the boards ranged between 0.5 and 1.6 N/mm2, and 480 and 3,563 N/mrn2, respectively. Mean thickness swelling (TS) and water absorption (WA) values ranged between 1.1 and 8.6%, and 31 and 51%, respectively. Analysis of variance showed that except for MOE, the levels at which the density, CaCI2 concentration, and cement-cane mixing ratio were used and their interaction had no significant effects on properties of the board. The relatively low strength and water resistance properties of the boards make them suitable only for use in low stressed interior applications. Further investigations are, however, required on the effects of different cane preparation procedures and other fabrication variables on board properties. This is necessary to provide the guidelines required to adequately control the fabrication process and optimize material properties.
Evaluation of some farm structure in South Western Nigeria
(2003) Mijinyawa, Y.; Oyebamiji, I. O.
A survey involving the use of questionnaires, personal communication, physical observation and photographic recording was undertaken in South western Nigeria comprising of Ekiti, Ogun, Ondo, Osun and Oyo states to identify the farm structures popularly used; materials used in their construction, their durability and maintenance culture adopted by the users. Farmhouses, cribs, barns, platforms, warehouses, silos, pens, yards and sheds, deep litter houses, palm fronds woven baskets, hutches and cages were the popular farm structures identified. Although a catalogue of materials is available for construction, cost was found to be a major factor in the selection of materials. There was extensive use of locally sourced materials such as wood, natural fibers and earth for the construction of the identified structures. The factors, which tend to reduce the service life and efficiency of these facilities, include roof leaks, abrasion of mud walls, decay and breakage of wooden members, corrosion of metal components, and pitting and cracking of concrete floors. Remedial measures taken include replastering of mud walls and cracked floors, addition of natural fibers to roofs and sealing of leaking points in galvanized roofing sheets, and replacement of broken wood components. These measures where adopted have proved quite useful in improving the efficiency and longevity of the structures. A culture of regular inspection and timely repair of damaged components to prolong the service life and reduce maintenance cost is recommended.
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.
Design, construction and performance evaluation of a drip irrigation system
(2004) Ewemoje, T. A.; Adewole, O. A.; Enujowo, O. O.
A gravitational drip irrigation system was designed and constructed using available materials; and tested for the use of small-scale farmers. The system has 4 laterals each 4m long, with each of the laterals having pressure-compensating emitters. This was evaluated based on its efficiency. Tests show that discharge per lateral is 8 1/hr And each of the emitters can deliver 2.1 1/hr with an operating head of 0.97m. The crop water requirement was based on the evapotranspiration rate for Ibadan climatic zone that was given as 5 mm/day. Water conveyance efficiency was 99%; Application efficiency approximates to 94.5% while overall system efficiency was 94.05 %. These results corroborate with Jess (2001) who put the overall efficiency of drip irrigation system at 90 % and above. The total cost of ownership was estimated at N10,030 while the total operating and maintenance cost was N308, as at February 2004.The efficiency of the system coupled with the cost of installation, maintenance and repair show that it is cost effective and viable.
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
Design of a gravitational drip irrigation system
(2005-02) Ewemoje, T. A.
The design and cost analysis of gravitational drip irrigation system was carried out in the Department of Agricultural Engineering Faculty of Technology University of Ibadan. This irrigation system was designed to suit farmlands not more than one hectare for small-scale farmers to irrigate vegetable crops. Before the design proper, preliminary studies were carried out and climatological data were collected, which was used to determine the rate of crop evapotranspiration used for the system's design i.e. 4.56mm/day for Ibadan climatic zone. The system has 100 laterals each of which is 50m long with each lateral having pressure-compensating emitters to distribute water and the mainline also 100m long. A model of the gravitational drip irrigation system was designed and tested. The test carried out on the model system shows that it can deliver 2.1-liter/hour of water with an operating head of 0.969m and the overall system's efficiency was found to be 94%. The efficiency of the system coupled with the installation and cost analysis shows that the system can be acquired and maintained by peasant farmers and still performs creditably well, when compared to the conventional drip irrigation system.
Agricultural engineering education in Nigeria
(CIGR Journals, 2005-08) Mijinyawa, Y.
Early agricultural engineering services required on Nigerian farms were provided by civil engineers and agronomists some of who later retrained to form the first crops of Nigerian agricultural engineers. Agricultural engineering training was substantially done overseas until about the early 1960s when local opportunities started to be available. Agricultural engineering education started with training in farm mechanization laying emphasis on tractorization in the colleges of agriculture and polytechnics, and later expanded to cover all aspects of agricultural engineering. Agricultural engineering education in Nigeria is offered by the universities, polytechnics and colleges of agriculture. Ownership and funding of tertiary institutions include the federal and state governments, private individuals and religious organizations. Quality assurance is achieved through setting of minimum academic standards and occasional programme accreditations by the Nigerian universities commission, the national board for technical education and the council for the regulation of engineering in Nigeria. Agricultural engineers are engaged in virtually all sectors of the economy. This paper discuses the historical development of agricultural engineering education in Nigeria highlighting the entry requirements, training and regulations, professional bodies and the sectors where the products are making their contributions towards the national development. It concludes by calling on all stake holders to understand and appreciate the role of the profession in national development and give it the desired support.