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Improving mechanical properties of aluminium alloy through addition of coconut shell-ash
(1970) A. Apasi; D. S. Yawas; S. Abdulkareem; M. Y. Kolawole
This paper investigates the microstructure and mechanical properties of aluminum alloy (Al-Si-Fe) reinforced with coconut shell-ash particulate. The aluminium (Al-Si-Fe) alloy composite was produced by a double-stir casting process at a speed of 700 rpm for 10 and 5 minutes at first and second stirring respectively. The samples produced from addition of 0-15 wt% coconut shellash particles (CSAp) were prepared and subjected to microstructural and mechanical properties testing. The results of the microstructural analysis of the composite reveal a fairly uniform distribution of the coconut shell-ash particles in the matrix with increase in volume fraction of CSAp. The mechanical property test results revealed that, hardness of the developed composite increased with increasing percentage weight of CSAp. Also the tensile and yield strength at 0.2% offset values of Al-Si-Fe/CSAp composite increased with percentage increase in CSAp up to 9% addition above which a little decrease in both tensile and yield strength was observed.Keywords: Matrix, coconut shell, mechanical properties, stir- casting, particulate, reinforcements
DEVELOPMENTS IN AUTOMOBILE EMISSION CONTROL
(2004-10) Abdulrahim, A. T; M.L. Usmah; B. Alkali
It is widely acknowledged that automobiles are becoming dominant contributors to atmospheric pollution in most of the world’s cities. Hence, the need to find effective methods of controlling automobile emissions becomes imperative. Available automobile emissions’ control measures which include various legislations and responses to legislations such as improvement in the state of the art controls, greater attention towards automobiles growth, improvement of engine design features, periodic tune-up, the use of alternative fuels and the development of non-fossil energy sources were reviewed in this paper.
VIABILITY OF SOLAR PHOTOVOLTAIC SYSTEM FOR RURAL ELECTRIFICATION IN NIGERIA
(2004-10) Alkali, A.B; A.T. Abdulrahim; B.M. Mustapha
Electricity availability in rural areas is identified as one of the social amenities that drastically reduce poverty problem by bridging the gap between the rural area and the urban centres. A suitable, cheap and reliable source of power, which could be minimally maintained and manipulated, is necessary to transform the life of an average rural family. This paper focuses on the solar system as a possible alternative to meet the above need. The paper presents a solar photovoltaic (PV) design and cost analysis for a typical single bedroom apartment. It also recommends integration of renewable energy into national strategies to cope with the economic and technical uncertainties that may constrain the supply of conventional energy.
Effect of moisture content on crackability of bambara groundnut using a centrifugal cracker
(Institute of Agrophysics, Polish Academy of Sciences, 2007-04-17) F.A. Oluwole; A.T. Abdulrahim; R.K. Olalere
One of the most tedious operations in processing bambara groundnut is the shelling operation. However, moisture content normally affects the handling and processing of agro materials, such as nut shelling/cracking. This study was conducted to determine the effect of moisture content on shelling efficiency of bambara groundnut using a centrifugal cracker. A 50 kg bag of bambara groundnut obtained from Damboa Local Government Area of Borno State, Nigeria, was divided into three groups. These groups were prepared for tests by soaking them in ordinary water at room temperature for different periods of 0, 60 and 90 min to obtain different levels of moisture content. Moisture content of each sample was determined by oven drying at 130°C for 6 h. The moisture content levels were found to be 5.3, 9.6, and 12.2% (d.b.) for samples A, B and C, respectively. The samples were subjected to impact energy through a centrifugal impaction device operating at an angular velocity of 1920 r.p.m., using three different types of impellers. Data obtained on the percentage of fully shelled pods and unbroken seeds, fully shelled pods with broken seeds, partially shelled pods and unshelled pods were statistically analysed. Results showed that both moisture content and impeller angula tions have a significant effect on these performance indices. The most effective performance was obtained at moisture content of 5.3% (d.b.), at which the shelling efficiency, percentage of dama ged seeds, percentage of partially shelled pods and percentage of unshelled pods were 96, 3.4, 0.6 and 0, 86.6, 3.6, 5.6 and 4.2, 85, 2.4, 5.4, and 7.2% for the forward facing impeller, radially posi tioned impeller and the backward facing impeller, respectively. The study further showed that development of a centrifugal impact bambara groundnut sheller with winnower would eliminate the tediousness of the present manual pod cracking methods.
Development and performance evaluation of impact bambara groundnut sheller
(Institute of Agrophysics, Polish Academy of Sciences, 2007-09-01) F.A. Oluwole; A.T. Abdulrahim; M.B. Oumarou
A centrifugal bambara groundnut sheller was designed, constructed and evaluated. The sheller consists of a feed hopper with a flow rate control device, shelling unit, separating unit and power system. Nine different impellers were used for the investigation at three different pod moisture contents. Results of the performance tests were examined using a 3x3x3 factorial design with moisture content, impeller slot angulations and number of impeller slots as variables. Results showed that moisture content, impeller slot angulations, number of impeller slots and interaction between these variables statistically affected the per formance indicators (shelling efficiency, percentage of breakage, percentage of partially shelled pods, percentage of unshelled pods and winnowing efficiency) at the significance level of 5%. The forward facing impeller with eight slots gave the best performance of 96% shelling efficiency, 3.4% breakage, 0.6% partially shelled pods. No unshelled pods were recorded, and winnowing efficiency of 97.3% was recorded at an average feed rate of 215.8 kg h-1
DEVELOPMENT OF A WATER AIR-CONDITIONER FOR THE SEMIARID REGION OF NIGERIA
(2007-10) Aji I; ; Balami A.A.; Abdulrahim A. T
The harsh weather condition experienced in Maiduguri between the months of February and June of most years has been a problem to the populace. Buying conventional air-conditioners to ameliorate this problem is difficult for the ordinary people in Maiduguri. In an attempt to lower the temperature of an average 16m2 room, an electrically operated water supply cooling system was designed, constructed and tested and was found to make the room conducive for human comfort. Guard sponge was selected and used out of the existing sponges because it has been found to reduce the ambient temperature better than others. Weather conditions of Maiduguri for the past fifteen years and the unreliability of electricity supply were put into consideration in the design of the water air conditioner. The machine was able to reduce the temperature of an average room (16 m 2 ) by 28% over a period of 42 minutes. The efficiency of the water air-conditioner with respect to the conventional unit is 60%. Seventy five per cent the machine parts were sourced locally, this is to make its production cheap and more affordable to low income earners.
DEVELOPMENT AND PERFORMANCE EVALUATION OF A SPINDLE PRESS FOR OIL EXTRACTION
(2007-10) Oluwole, F.A; A.T. Abdulrahim; N.A. Aviara
A manually operated spindle oil press adaptable to rural areas was designed, constructed using locally available materials and tested to evaluate its performance. The spindle press, which consists of tool frame, power transmission unit made of a spindle and its lever arm, and oil expression unit comprising of the upper and lower press plates and the perforated cage, operates on the principle of power screw to express oil from milled oil seeds. Each of these components was analyzed and the results obtained were used as parameter for sizing and fabrication of the components. The raw material used for testing the developed spindle press was groundnut paste and a nylon clothing material was used as filter. Results of the performance tests carried out on the machine using groundnut paste showed a maximum oil recovery of 78.1% and the cake produced is of the same quality when compared with those produced with the traditional method. Also the oil extraction time is reduced by about 50%
Small Scale Biochar Production Technologies: A Review
(Scholarlink Research Institute, 2010-12-01) Odesola, Isaac F.; Owoseni, Tunji Adetayo
This paper is set to review the available small scale biochar production technologies. Biochar production technologies are a few of the green technologies that seek to rid the environment of green house gases (GHG). The products of this technology are biochar and biofuels (oil and syngas). Variant methods of this small scale production are known. The use of single (metal) container to two barrels is common, while some units are built of ceramic materials like fired brick. However, there is no published work stating the production of biochar in Nigeria, as at the time of this compilation.
Development of local technology for a small-scale biochar production process from agricultural wastes
(Scholarlink Research Institute, 2010-12-01) Odesola, Isaac F.; Owoseni Tunji Adetayo
A charcoal fired reactor for small-scale production of biochar was successfully designed, fabricated and tested. The method of biochar production offered by this equipment was evaluated by comparing its output with a single barrel method of production. The results obtained during the test indicated that the efficiency of the equipment based on its output per kg of Cocoa pod husk was 79.9%. It has the capacity to produce 18.3 kg of Biochar from Cocoa Husk per day using 1 bag of local Charcoal. Cocoa pod Husk can be effectively used as raw material for Biochar production. The Specific Heat Capacity of Cocoa pod Husk was obtained as 3.8 kJ/kg K using the Choi and Okos model. The equipment can be afforded by small scale farmers at production cost of -24, 600.00. This machine can be easily used and maintained without any formal training. The reactor is therefore appropriate for use by subsistent farmers, and households for producing biochar on a small scale.
DEVELOPMENT OF COMPUTER INTERFACE PROGRAM FOR THE MAINTENANCE PLANNING AND SCHEDULING OF DANGOTE FLOUR MILLS, ILORIN, NIGERIA
(FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA, 2012) Ajao, K. R.; Issa, W. A.; Muhammed, B. H.
This work developed an interface for the planning and scheduling of plant maintenance operations at Dangote Flour Mills, Ilorin Nigeria. The focus of this computer based maintenance planning is to ensure continuous operations of equipment, plant and machineries and reduce operation stoppages or downtimes. It provides interactive modules whereby industrial activities can be assigned to employees by the company's management while employees can have an immediate view of job schedule, simplifies the process of requesting for work to be performed and manage the issuance of work permits, control parts and inventory, keep good record of equipment and appropriate safety management through proper documentation of accidents that may occur in plant operations among others. The paper form of planning and scheduling industrial work activities is tedious, past maintenance and scheduling records are always difficult to retrieve and in many instances when the stock level becomes zero all industrial production seizes and its attendant consequences.
Computer Aided Design and Drafting of Helical Gears
(2012) Akinnuli B. O; Ogedengbe T. I; Oladosu K. O
An interactive user friendly low cost software called “CADDgear” was developed in this study to facilitate the design and drafting of helical and spur gears thereby generating reliable data for use in manufacturing process. The software was developed, using JAVA programming language, as a tool for determining the design parameters and producing accurate and efficient 3D (three dimensional) and 2D (two dimensional) detail working drawings of helical gears. The study considered the existing approaches in use for the design of helical gears and then established a design analysis procedure for helical gear design. The established procedure was implemented through the developed software so that a substantial saving in term of time and cost of production of the design is obtained. The outcome of this research would enhance the designer’s productivity by reducing the time required to synthesis, analyze and document helical gear design. This would permit a thorough analysis of a large number of design alternatives. Results generated by the software shows very good agreement with that obtained through manual calculation using the established procedure. It was observed that the developed software successfully increase productivity over manual gear design and drafting by approximately thirty-four times in term of the time required for the design
Analysis of Two Dimensional Heat Transfer Problem Using Spreadsheet Approach
(Energy Technology and Management conference, 2012) A.A Oladosu; I.F Odesola; A.S Olawore
The storage of thermal energy in the form of sensible and latent heat has become an important aspect of energy management with the emphasis on efficient use and conservation of the waste heat and solar energy in industry and buildings. Heat storage materials absorb heat through standard heat transfer mechanisms, e.g., radiation, conduction, and convection. The need for developing software for solving these problems become imperative because it has necessary functions for solving a large class of engineering problems. The aim of this project is to demonstrate how Spreadsheet can be used for solving heat transfer problems in an arbitrary geometry. Survey was carried out on various geometries. An example considered was a chimney. The symmetry of the geometry was considered. Energy balances were obtained and finite difference formulations were made. Finite difference equations for various nodes were determined. Spreadsheet was set up for the problem. Various temperature distributions were obtained. Temperatures are highest at the inner wall (but less than 300oC) and the lowest at the outer wall (but more than 260 k), as expected. The average temperature at the outer surface of the chimney was 352.65k. The rate of heat loss through the 1m long section of the chimney was determined both manually and numerically.
Design and development of vapor absorption refrigeration system for rural dwellers
(Covenant University, 2012) Adekeye, T; Oyedepo, S.O; Oyebanji, J.A
Heat Stress as A Measure of Human Level of Comfort in A Semi-Arid Zone, Maiduguri, Nigeria
(Research | Reviews | Publications, 2012) Abdulbaqi T ABDULRAHIM; Richard B MSHELIA; Olajide G STEPHEN; Emmanuel T KYAUTA
This study examined thermal stress and physiological comfort in Maiduguri, Nigeria using thermal heat stress index as a measure of human comfort. Dry-bulb temperature, Relative humidity, and Air velocity were measured in three observatory sites (class room, under neem (azadirachta indica) tree and under direct sunlight) within the Faculty of Engineering University of Maiduguri, Nigeria between the hours of 7.00 am and 5.00 pm on some days from October to December 2010 in order to establish the physiological responses to thermal stress and disorder. The data were analyzed using Effective Temperature (ET) and Relative Stress Index (RSI). The mean ET mean ET obtained vary from 23.58oC to 31.18oC, while the RSI values vary from 0.12 to 0.49 for the period just after the raining season. And for the hammatan period, the mean ET mean ET vary from 19.31oCto 29.09oC , while the RSI values vary from-0.01 to 0.38. The results showed that the three locations are generally comfortable during the morning hours and become uncomfortable as the day progresses. The class room was found to be the most comfortable during the period of the investigation while the location under the sun recorded the highest level of discomfort in both seasons.
Computer Application for Maintenance Planning and Scheduling of Industrial Plant
(International Institute for Science, Technology and Education, 2012-01) Ajao, K. R.; Issa, W. A.; Muhammed, B. H.
Plant maintenance involves all activities carried out on a machine to ensure a zero downtime of operation. Maintenance activities vary from one industry to the other but the basic maintenance activities are mainly to ensure continuous operations of equipment, plant and machineries. Over the past few decades, the various industrial work activities and maintenance operations are performed without a concrete plan (schedule) or are performed via manual paper work. Industrial operations are usually complex and recurrent activities. Analysis has shown that lack or insufficient maintenance coordination, has accounted for the poor performances and inefficiencies of many industries. Thus, it is pertinent to deduce a planned maintenance organizer or a computer aided design for the planning and scheduling of industrial work activities. This becomes important as computer has revolutionalized industrial activities with the development of modern high level computer programming languages such as visual basic by Microsoft among others.
Design analysis of solar bi-focal collectors
(2012-02-02) Abdulrahim A; Diso I. S; Abdulraheem A. S
This study carried out the design analysis of solar bi-focal collectors with the basic units comprising the paraboloid concentrators, receivers and support/connectors. The design of the receivers is such that it works on thermo-siphon principle while the heat energy requirement for each receiver is 650 kJ. Solar energy required to provide the needed power input in the collector’s receiver is amounted to 0.967 kJ/s. The results of the analysis revealed that each collector has diameter of the receiver of 0.3 m, aperture diameter of 1.4 m and internal surface area of 1.53 m2. The materials and dimensions of parts were selected based on the design specifications. The design analysis will serves as basis for the development of a solar tracking bi-focal collector system for possible steam generation.
3D Flow around a Rectangular Cylinder: a review
(AFRREV STECH, Vol. 1 (2) April-July, 2012, 2012-04-01) Odesola, Isaac F.; Olawore, Ayodeji
Turbulent flows around three-dimensional obstacles are common in nature and occur in many applications including flow around tall buildings, vehicles and computer chips. Understanding and predicting the properties of these flows are necessary for safe, effective and economical engineering designs. This paper presents the review of 3D flow around a rectangular cylinder using large eddy simulation as the turbulence model and the computational study is developed in the frame of the Benchmark on the Aerodynamics of a Rectangular Cylinder (BARC). Different simulations around bluff bodies were reviewed and the results obtained through different methodologies are presented. The effect of change by vortex shedding on the magnitude of fluid forces of rectangular cylinders are examined and reported. The aerodynamic integral parameters obtained from different papers are compared.
Random vortex element modelling of groundwater flow
(World Academy of Science, Engineering and Technology, 2012-06-01) Kareem, M.W.
Exploitation of groundwater for both domestic and industrial uses has continuously been undertaken in different parts of the world. The proper harnessing of available water required adequate analysis of the flow in the aquifer. Successful attempts have been made using finite difference and finite element methods. However, the possibility of vortex element method as an alternative technique was considered in this work. A model was developed using random vortex element method to simulate groundwater flow with constant head at the aquifer boundary. This was carried out by transforming the governing equation for groundwater flow into a typical vorticity equation for vortex method. The model was then used to determine groundwater head at varying time for Lagos basement complex with transmisivity and storativity of 5.5 X 10-5 m and 6.840796 X 10-2 respectively. The aquifer thickness varied from 4.0 m to 7.0 m. At the aquifer thickness of 4.0m the predicted groundwater heads varied from 0.0 m to 0.024833690 m, while at the aquifer thickness of 7.0m the predicted heads varied from 0.0m to 0.159134 m for varying time step at 0.1 s. The head differs only from literature value by 2.44%. Random vortex element method is therefore a viable numerical tool for predicting the groundwater flow parameters of the aquifer at any desired location.
Modelling and Simulation of Low Calorific Value Municipal Solid Waste Incineration
(Research | Reviews | Publications,, 2012-09) Mohammed B OUMAROU; Abdulbaqi T ABDULRAHIM; Mohammed DAUDA
The paper focused on the mathematical modelling and simulation of low calorific value municipal solid waste incineration in semiarid region. Municipal solid wastes were collected and analysed; from which wood samples were taken and incinerated using a prototype incinerator. A mathematical model, based on Fourier series (FS) and finite elements method (FEM) was developed, ran and validated using experimental and literature data. Critical minimum volume of 4.93 m3 or about 6 % of the total volume of the incinerator would be needed at 20% moisture content refuse and a critical maximum volume of 51.10 m3 or 69.21% of the total volume, would be needed at 50% moisture content. The ignition time and the time at which the combustion becomes self-sustaining are greatly influenced by the moisture content. Critical drying temperature was found to be 711.44 K. The grid size had little or no effect on the simulated results. The developed model can accurately predict the critical sizes and performance of the actual plant even at its virtual stage. There is need to optimize the critical drying temperature and mathematical model /physical model correlation which would help improve the efficiency of the process and better understand the drying mechanism involved.
Municipal Solid Waste Generation, Recovery and Recycling
(Research | Reviews | Publications, 2012-10) Mohammed B OUMAROU; Mohammed DAUDA; Abdulbaqi T ABDULRAHIM; Alhaji B ABUBAKAR
The paper presents a case study focused on waste generation, material recovery, and the recycling potential of municipal solid waste in Maiduguri, Nigeria. The municipal solid waste (MSW) generation was estimated using a fuzzy logic based mathematical model followed by a collection scenario thought of, adopted and tested within two planned residential areas; the University of Maiduguri campus and the 202, 303 housing estates of the Maiduguri metropolis. Data obtained were analyzed using simple statistical methods. The mathematical model predicted 255 tonnes of MSW against 226.63 tonnes by collection estimates. An important amount of recyclable materials was found to be generated within the study area. Incurred fuels expenses on the trucks alone, do exceed the monthly wages of 400 waste collectors. MSW collection, material recovery and recycling are alternatives to fight poverty, and contribute immensely towards social re-insertion of marginalized people. Further research is needed on the waste production equation for estimates of waste generation in not well planned areas.

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