Browsing by Author "S. Abdulkareem"

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    Archachatina marginata bio-shells as reinforcement material in metal matrix composites
    (2017) M.Y. Kolawole; J.O. Aweda; S. Abdulkareem
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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
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    PERFORMANCE EVALUATION OF SOLAR OVEN USING KAPOK WOOL AS INSULATION MATERIAL
    (2020-12) A. T. Abdulrahim; S. Abdulkareem; M. Haruna; A. S. Abdulraheem; F. A. Oluwole; G. M. Ngala; U. A. Mukhtar
    Solar ovens are among common devices which utilize insulation materials because of their ability to retards heat transfer by acting as barriers in the path of heat flow. Previous solar box cookers have used cotton, saw dust, and fibre-glass as insulation materials but none has used Kapok wool despite its potential. This study is aimed at the performance evaluation of solar oven using Kapok wool as the insulation material. The solar box oven designed is of the size 59 x 56 x 36cm dimensions made of plywood, with an aperture area of 3304cm2 double glass cover and an oven’s floor area of 1225cm2 made of aluminum. Kapok wool was used to line the oven’s walls and floor serving as insulator. The solar box oven was tested at the University of Maiduguri, Borno State, Nigeria. It was tested without load to determine its stagnation temperature and to check its endurance under stagnation conditions. Similarly, a water boiling test was conducted to cook rice and beans. The results show that maximum stagnation temperature was 165.1°C and maximum overall daily thermal efficiency of 19.44% was achieved on a clear day test without reflector. The field test of the solar oven demonstrated its ability to cook rice and beans well with 1 kg of rice cooked under 2 hours, while 1 kg of beans was cooked under 1 hour 45 minutes on the same day. This performance demonstrated the suitability of Kapok wool as insulation material for solar ovens.
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    PHYSICAL AND MECHANICAL CHARACTERISTICS OF CHARCOAL, SAWDUST AND SUGARCANE BAGASSE AS SOLID FUEL MATERIALS
    (2017) S. Abdulkareem; H.A Badejo; I.I Ahmed; J.A. Adebisi; Y. Taiwo; T.K Ajiboye; A.T Abdulrahim
    This paper reports on the physical and mechanical characteristics of briquettes produced from charcoal, sawdust and sugarcane bagasse using molasses with sodium silicate as binders. Charcoal, sawdust and sugarcane bagasse were mixed in a respective ratio of 20:20:60, 20:30:50, 20:40:40, 20:50:30 and 20:60:20. The briquettes were produced using Budenberg dial gauge compression machine, with a pressure of 64 MPa at 120 seconds dwell time. Physical properties (relaxation ratio, compaction ratio and shattering index) and mechanical property (compressive strength) of the produced briquettes were investigated. Results show that briquette with sample composition of 20:30:50 has better physical properties with a relaxation ratio of 1.562, a compaction ratio of 7.573 and shatter index of 99.6%, while sample with ratio 20:40:40 has the highest compressive strength of 55.43 kN/m2 .
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    THERMAL AND MECHANICAL PROPERTIES OF CLAY AND DROP-OFF OF CEIBA PENTANDRA (KAPOK) PLANT WOOL MIXTURE
    (2020-06) A. T. Abdulrahim; S. Abdulkareem; S. A. Abdulraheem; W. J. Mohammed
    This study is aimed at the investigation of the effects of the addition of clay to drop-off of Ceiba pentandra (Kapok) plant wool on the thermal and mechanical properties of the materials produced. Because of the considerable increase in the use of insulations in many heat devices, process and systems, and dependence on imported insulations, the need to process natural fibre insulations to form rigid or semi-rigid material using appropriate and sustainable binding material cannot be over emphasized. For this study, Kapok wool and clay mixture were investigated. Five samples were prepared: Sample A was 100% Kapok wool while samples B, C, D, and E were mixture of Kapok wool and Clay in water with varying percentage of clay quantities (Kapok to Clay ratio; B 2:1, C 2:1.5, D 2:2.5, E 2:3.5). The samples were prepared into cylindrical shapes, compressed and dried. The Thermal conductivity meter on Armfield Heat transfer equipment was used to find the thermal conductivity of each sample, while the thermal diffusivity and thermal resistivity of samples were determined using appropriate formula. Universal Testing Machine (Model: FS 50AT) was used to determine the stress at Yield and Young Modulus of elasticity for samples B, C, D, and E. Results show that the density of sample increases with increase in clay content. Thermal conductivities of the samples after the addition of clay ranges between 0.027 (W/mK) and 0.013 (W/mK). Reversed was the case for Thermal Resistivity, the value of thermal resistivity first decreases with addition of clay content (sample B) and then started increasing with increased clay content in the samples, and the values range from 37.037 to 76.923mKW-1. Thermal diffusivity of sample decreases from 1.2762 x10-3 m2 /s to 0.2810 x10-3 m2 /s with increasing clay content. Results also show that the Stress at Yield of samples range from 0.012 N/mm2 to 0.022 N/mm2 while the Young Modulus of elasticity range from 0.113 N/mm2 to 0.222 N/mm2 . Kapok wool – Clay combination of ratio 2:3.5 (Sample E) have the highest value of thermal resistivity and lowest thermal diffusivity, though with high density, which suggests it to be the best among samples in the study for insulation purposes. The products are recommended for use as insulations of thermal storage for medium temperature applications