Nigerian Journal of Technological Development <p>The Nigerian Journal of Technological Development is now a quarterly publication of the Faculty of Engineering &amp; Technology, University of Ilorin, Ilorin, Nigeria. It publishes original high-quality articles focusing on all aspects of Engineering and Applied Sciences in March, June, September and December. Manuscripts are double-blind peer-reviewed and if found suitable, published according to the subject matter as a <strong>Research Paper, Review Paper or a Technical Note.</strong></p> <p>Other websites associated with this journal:&nbsp;<a title="" href="" target="_blank" rel="noopener"></a></p> Faculty of Engineering & Technology, University of Ilorin, Ilorin, Nigeria en-US Nigerian Journal of Technological Development 0189-9546 <p>In accordance with the Copyright Act of 1976, which became effective January 1, 1978, the following statement signed by each author must accompany the manuscript submitted: "I, the undersigned author, transfer all copyright ownership of the manuscript referenced above to the Nigerian Journal of Technological Development, in the event the work is published. I warrant that the article is original, does not infringe upon any copyright or other proprietary right of any third party, is not under consideration by another journal, and has not been published previously. I have reviewed and approve the submitted version of the manuscript and agree to its publication in the Nigerian Journal of Technological Development." A copyright transfer form may be downloaded from the NJTD Website ( Author(s) will be consulted, whenever possible, regarding republication of material. All authors must have access to the data presented and the authors and sponsor (if applicable) must agree to share original data with the editor if requested.</p> Development and Evaluation of the Operational Parameters of a Rotary Oven <p>Developing an efficient rotary oven that is capable of addressing the issue of long baking duration and uneven heating distribution during baking could aid in encouraging indigenous use of the oven by small and medium scale bakeries in developing countries. This study aimed to develop and evaluate the performance of a rotary oven. Taguchi experimental design was used to investigate the influence of oven temperature (160, 180, 200°C) and oven rack speed (0, 10, 20 rpm) on the physical properties (baking time, mass, surface area, specific volume and density) of bread produced from the rotary oven. The baking capacity and efficiency of the rotary oven were 16 kg h<sup>-1</sup> and 94%, respectively. Investigation showed that baking time ranges from 20 to 82 min, bread mass (884 to 925.7 g), surface area (1050 to 1370 cm<sup>2</sup> ), specific volume (2.36 to 3.70 cm3 g <sup>-1</sup> ) and density (0.25 to 0.39 g cm<sup>-3</sup> ), respectively. The optimum baking time (20 min) was achieved at 200°C oven temperature and 10 rpm oven rack speed. The oven could be adopted for both domestic and industrial production of bread and other bakery products.</p> <p><strong>Keywords</strong>: Bread, oven temperature, oven rack speed, taguchi, rotary oven. </p> M.S. Sanusi M.O. Sunmonu A.L. Adepoju T.O. Abodunrin H.A. Ajibade Copyright (c) 2021-03-11 2021-03-11 17 4 239 249 10.4314/njtd.v17i4.1 Effect of Thermal Pretreatment on the Yield of Biogas from <i>Microcoleous Vaginatus</i> <p>Biomass is being looked upon as one of the promising renewable energy sources for the future, with growing interest in microalgae conversion into biogas through anaerobic digestion. Recently, the ability of microalgae to treat waste water has doubled its potentials material today. However, in spite of the progress made in that regards, there are still challenges of algae conversion to biofuel, due to the presence of complex cell wall in some algae. Cell wall inhibits bacteria growth during degradation. In this research work 10 grams of <sup>Microcoleous vaginatus</sup> was treated in an oven at varying temperatures of 70, 75 and 80 <sup>o</sup>C for an hour, out of which 4 g was measured into 250 ml serum bottle for digestion at mesophilic temperature of 37 <sup>o</sup>C. Based on the results of proximate analysis, 69%<br>increase in carbohydrate was attained with 72.7 – 148% reduction in moisture content. The biogas yield of untreated sample was 4.36 mLg−1 VS, while, pretreated samples at 70, 75 and 80 ℃ produced 8.39, 9.07 and 9.38 mLg−1VS (volatile solid) of biogas. This&nbsp; corresponds to 92, 108 and 115% higher than that of untreated samples. However, thermal treatment of <em>M. vaginatus</em> prior to digestion show positive effect on carbohydrate extraction and enhanced biogas and methane yield as well. Therefore, this makes the substrate a good feedstock for biogas production.</p> <p><strong>Keywords:</strong> Biomass, pretreatment, thermal, anaerobic digestion, degradation, <em>Microcoleous vaginatus.</em> </p> M. Haruna O.R. Momoh S. Bilal Copyright (c) 2021-03-11 2021-03-11 17 4 250 256 10.4314/njtd.v17i4.2 Optimization of Crude Oil Biodegradation of Fungi Isolated from Refinery Effluent Site using Response Surface Methodology <p>The activities involved in the production and exploration of crude oil has constantly polluted the environment. This study investigated the ability of an indigenous fungus to utilize petroleum hydrocarbon. Response Surface Methodology was used to optimize the effects of pH, microbial concentration (spores/ml), and contact time (days) on the crude oil removal efficiency in refinery effluent. <em>Monocillium sp</em>. was isolated and used for the treatment of refinery effluent due to its predominance in the contaminated soil. Twenty experimental runs were analyzed to determine the effect of pH, microbial concentration and contact time on the oil removal efficiency. From the<br>experimental results obtained, a maximum oil removal efficiency of 98.42 % was achieved at a pH of 6.5, contact time of 14 days, and a microbial concentration of 3 spores/ml. The results obtained showed the percentage of crude oil removal in the effluent sample&nbsp; increased with an increase in time. Optimization of the experimental result was achieved at a removal efficiency of 98.59 %, a contact time of 13.96 days, a pH of 6.85, and a microbial concentration of 3.01 spores/ml. The findings of this study revealed that <em>Monocillium sp.</em> is a viable hydrocarbon degrader, and can be used in the bioremediation of petroleum contaminated environments.</p> <p><strong>Keywords</strong>: Response surface, optimization, bioremediation, hydrocarbon, removal efficiency, <em>Monocillium sp.</em> </p> U.C. Odili F.B. Ibrahim E.M. Shaibu-modagbe H.I. Atta Copyright (c) 2021-03-11 2021-03-11 17 4 257 268 10.4314/njtd.v17i4.3 Modelling and Analysis of Photovoltaic System under Partially Shaded Conditions using Improved Harmony Search Algorithm <p>With the increasing penetration of solar electricity in residential, institutional and commercial centres around the globe, the phenomenon of partial shading (PS) in Photovoltaic (PV) power generation is gaining attention. Under Partial shading condition (PSC), cells that are shaded tends to have an equivalent current with cells that are unshaded in series-connection, due to this, the shaded cells operates in reverse bias and consequently becomes load and consumes the generated power. This causes a serious problem known as hotspot. This is characterized by the presence of excessive heat which consequently reduces the total generated power. Recently, researchers use the technique of bypass diodes across the PV cells so that the problem of partial shading can be reduced, but this solution taken alone, has made the nonlinearity and complexity of the system to increase. The shaded cells generate multiple peaks with only one global peak. Conventional Maximum Power Point Tracking (MPPT) algorithms do not differentiates the global peak from local peaks which may end up tracking local peak as global peak, this results in serious power loss. This paper seeks to solve this problem by modelling a PV system under PSC and through the application of Improved Harmony Search algorithm (IHSA) and variable step Perturb &amp; Observe (P&amp;O) to track the global peak instead of local peaks. Simulation was done in MATLAB/Simulink 2018a environment, and the results under standard test condition (STC) and PSC showed that the proposed IHSA had an improvement of 25%, 3.17% and 2.27%, 3.07% and 2.21%, 3.26% and 2.26% when compared with the improved particle swarm optimization (IPSO) under STC and PSC conditions respectively, which had a better advantage of minimizing power oscillation and improving the efficiency of the system, improved MPPT tracking, reduced error and a better tracking efficiency in both conditions.</p> <p><strong>Keywords</strong>: MPPT, photovoltaic system, partial shading, tracking efficiency, Harmony search algorithm</p> S. Sani G.A. Olarinoye P.U. Okorie Copyright (c) 2021-03-11 2021-03-11 17 4 269 277 10.4314/njtd.v17i4.4 Investigating the Effects of Pentanol and Biodiesel Blends on the Performance and Emission Characteristic of Compression Ignition Engine <p>Emissions from use of fossil fuels have consistently posed significant threat to the environment and wellbeing of man. This has prompted several studies aimed at finding solution to the emissions and their effects. The aim of this research is to investigate the effect of adding pentanol and biodiesel from Moringa Oleifera seed to pure diesel content of 70% by volume. pentanol and biodiesel make up the remaining 30 percent by volume and were also varied, with pentanol percentage being increased from 2 percent to 8 percent so as to carefully monitored the effects of adding pentanol while the Moringa oleifera biodiesel made up the balance for the 30%. These blends were labelled according to the percentage composition of biodiesel and pentanol (B28P2, B26P4, B24P6, B24P6, and B22P8). The physicochemical properties of all blends such as viscosity, density, pour point, acid value and iodine value determined. From the result of the engine performance and emission tests, B24P6 blend has been noted to have the best engine performance parameters, haven shown the best engine brake power of 19.787 kW, and with the highest engine brake thermal efficiency of 19.78%.While in term of engine emission, B22P8 blend, have the lowest Nitrogen oxide (NOx) emission, with a value of 82.4994 ppm which is about 3% lower than that of pure diesel, while B26P4 have the lowest carbon monoxide (CO) emission among all the samples tested with value of 6.1556 ppm which is about 58% lower than that of Petro diesel. However, blends appeared to have good brake mean effective pressure except for B22P8 which have the lowest BMEP, that’s about 2.8% lower than that of Petro diesels. Conclusively, the addition of Moringa oleifera biodiesel with pentanol improved the diesel quality, yielding good improvement in engine&nbsp; performance and emission.</p> <p><strong>Keywords</strong>: Diesel, biodiesel, pentanol, biofuel blends, Moringa oleifera seed, engine emissions </p> I.U. Ibrahim M. Idris I.A. Hussain M.U. Kaisan I. Ajunwa A. Shitu Copyright (c) 2021-03-11 2021-03-11 17 4 278 285 10.4314/njtd.v17i4.5 Appraisal of Aggregate Technical, Commercial and Collection Losses in Nigerian Electricity Distribution System <p>From a practical point of view, no power system is free of losses. Power system losses, especially in distribution systems are usually high and result in increasing the cost of operations to the electric utilities and the price tag of electricity to the consumers. Aggregate Technical, Commercial and Collection (ATC&amp;C) losses is a reliable parameter that reveals the true energy and revenue loss conditions of distribution systems. In this paper, mathematical models were developed for the determination of billing efficiency, collection efficiency, and ATC&amp;C losses using Life Camp Area Office’s network of Abuja Electricity Distribution Company Plc Nigeria, as a case study. The average billing efficiency, collection efficiency and ATC&amp;C losses for the period under review were found to be 89.73%,<br>84.80%, and 23.79% respectively. An understanding of appraisal of these losses is important to the power system Engineers, energy policy makers, and the power firms as it enables areas of high losses in the network to be identified, which will give room for credible investment plans and subsequent monitoring of the losses.</p> <p><strong>Keywords:</strong> ATC&amp;C losses, billing, energy, distribution system, revenue </p> U.A. Dodo M. N. Nwohu I.N. Abubakar M.A. Dodo Copyright (c) 2021-03-11 2021-03-11 17 4 286 294 10.4314/njtd.v17i4.6 Effects of Tractorization and Organic Manure on Physical Properties of Sandy Loam Soil in Abeokuta, Nigeria <p>Soil compaction has effect on soil physical properties which could affect crop growth and yield. This study was conducted to determine the influence of incorporating organic materials and load application (tractorization) on the physical properties of sandy loamy soil in Abeokuta, Ogun State, Nigeria. Organic materials were cow dung, poultry and swine manure. Application rates of organic manures were 0 (control), 5 and 10 tonnes per hectare. Forty-five plots measuring 5 by 3 m were established in a complete randomized block experimental design with three replications making a total of 135 plots. Load application was done using an MF 435 tractor coupled with a 20-disc harrow at 0 (control), 5, 10, 15 and 20 passes. Penetration resistance, bulk density, gravimetric moisture content and<br>porosity were determined using standard procedures. Penetrometer resistance at these passes were 392.2, 293.3, 285.0, 302.0 and 224.9 kPa respectively with significant differences between treatments (P≤0.05). Mean bulk density for the passes were 1.21, 1.26, 1.31, 1.27 and 1.29 g/cm<sup>3 </sup>respectively and bulk density increased with tractor passes. The effect of tractor passes, and manure incorporation rate did not have any significant effect on gravimetric moisture content. Poultry manure increased bulk density and penetrometer resistance on plots than swine manure and cow dung hence poultry manure at 10 t/ha can be incorporated on a sandy loam soil to enhance soil fertility and sustainability.</p> <p><strong>Keywords</strong>: Tractorization, organic manure, sandy loam, penetration resistance, bulk density</p> P.O.O. Dada J.J. Musa O.O. Olla J.O. Ohu J.K. Adewumi Copyright (c) 2021-03-11 2021-03-11 17 4 295 300 10.4314/njtd.v17i4.7 Effect of Tensile Load on the Mechanical Properties of AlSiC Composite Materials using ANSYS Design Modeller <p>Aluminium Silicon Carbide (AlSiC) composite materials are used in the electronics industries and other manufacturing companies hence, manufacturing of AlSiC composite materials with the right properties for different applications are vital to most industries. The challenge of testing the same specimens for different properties remains, because most of the tests carried out are destructive. Hence, the use of ANSYS finite element simulation software for the design and analysis of a flat bar specimen. Loads between 3 kN to 21 kN were applied on the specimen since it is within the operating limit of a Universal Tensile Testing Machine (UTTM), while both ends are fixed. The AlSiC composite materials used in this study have a composition of 63 vol% Al (356.2) and 37 vol% SiC and, the results<br>showed that stress was directly proportional to strain. While the calculated Young’s modulus from the stress versus strain plot was approximately 167 GPa for the different tensile loads applied. In addition, the total deformation of the AlSiC composite material increased as the load was increased. Also, the highest deformation of the material was observed around the centre of the test specimen. This is synonymous with the failure observed in practical testing of specimens.</p> <p><strong>Keywords</strong>: AlSiC, tensile load, aluminium MMC, stress analysis, deformation, ANSYS</p> Mathias Ekpu Copyright (c) 2021-03-11 2021-03-11 17 4 301 305 10.4314/njtd.v17i4.8 Mechanical Performance of Recycled Aggregate Concrete Containing Lathe Waste Steel Fibre <p>The increasing demand, diminishing supplies, and growing pressure on natural resources have necessitated recycling and reusing waste. Several kinds of research have been done on the reuse and recycling of debris from building projects. Thus, with a view to the reuse of waste materials, the elimination of environmental contamination, the reduction of overhead costs of concrete, and the extension of the service life of concrete structures, this research aimed to study the feasibility of utilizing recycled concrete aggregate (RCA) with constant inclusion of waste steel fibre (LWSF) in concrete by evaluating its workability, compressive and splitting tensile strengths. A concrete mix ratio of 1:2:4 by weight of cement, sand, and granite was adopted with a water-cement ratio of 0.45. Five different concrete mixes were prepared in this study; one normal aggregate concrete (NAC) and four (4) other mixes with 25%, 50%, 75%, and 100% recycled aggregate content with a constant 1.5% addition of LWSF. The result of workability shows a reduction with an increase in the percentage replacement level. The recycled aggregate concrete (RAC) was characterized by lower compressive strength as compared with the NAC. When the replacement ratio increased from 25% to 50%, a significant reduction of about 14% and 30% were observed in the compressive strength at 7-days, but at 28-days slight increase in the compressive strength was observed. Also, a decrease in splitting tensile strength as the percentage replacement of crushed granite (CG) with RCA is increased was observed. Overall, the findings showed that the RAC-containing LWSF is environmentally sustainable and would significantly reduce the global greenhouse impact and building materials' overall quality.</p> <p><strong>Keywords</strong>: Recycled concrete, lathe waste, steel fibre, compressive strength, tensile strength </p> S.A. Alabi C. Arum Copyright (c) 2021-03-12 2021-03-12 17 4 306 311 10.4314/njtd.v17i4.9 Adsorptive and Photocatalytic Properties of Green Synthesized ZnO and ZnO/NiFe<sub>2</sub>O<sub>4</sub> Nanocomposites for Tannery Wastewater Treatment <p>This study investigated adsorptive and catalytic behaviour of ZnO and ZnO/NiFe<sub>2</sub>O<sub>4</sub> nanocomposites for the removal and degradation of organic pollutants in tannery wastewater. ZnO and ZnO/NiFe<sub>2</sub>O<sub>4</sub> nanomaterials were synthesized via a green method using Zn, Fe and Ni salts precursor and leaves extract of Anacardium occidentale (linn.). Subsequently, the synthesized samples were characterized by different analytical tools. The adsorptive and catalytic performance of the prepared nanomaterial were assessed using reduction in Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and Total Organic Carbon (TOC) in tannery wastewater as indicator parameters. High Resolution Scanning Electron Microscope (HRSEM), High Resolution Transmission Electron Microscope (HRTEM), and X-Ray Diffraction (XRD) analysis of ZnO and ZnO/NiFe2O4 confirmed the formation of hexagonal wurtzite nanoparticle and cubic spinel phase with an average crystallite sizes in the range of 13- 28 nm and 30.44 – 42.53 nm respectively. XRD analysis confirmed no change in the polymorph of ZnO upon the addition NiFe<sub>2</sub>O<sub>4</sub>. XPS spectrum showed the existence of the elements in the following oxidation state (+2) for Zn, (+1, +2) for Ni and (+2 and +3) for Fe. BET analysis revealed order of the specific surface area of ZnO/NiFe2O4 (44.61 m<sup>2</sup>/g) &gt; NiFe<sub>2</sub>O<sub>4</sub> (40.39 m<sup>2</sup>/g) &gt; ZnO (8.91 m<sup>2 </sup>/g). The adsorptive and photocatalytic results revealed that 3% ZnO/NiFe<sub>2</sub>O<sub>4</sub> exhibits higher efficiency compared to ZnO and NiFe<sub>2</sub>O<sub>4</sub> nanoparticles alone and in the order of 3% ZnO/NiFe<sub>2</sub>O<sub>4</sub> &gt; NiFe<sub>2</sub>O<sub>4</sub> &gt; ZnO. The study revealed that the prepared nanomaterial behaved better as photocatalyst than as nanoadsorbent.</p> <p><strong>Keywords</strong>: Adsorption, photocatalytic technology; ZnO; ZnO/NiFe<sub>2</sub>O<sub>4</sub>, tannery wastewater </p> J.O. Tijani U.A. Aminu M.T. Bankole M.M. Ndamitso A.S. Abdulkareem Copyright (c) 2021-03-12 2021-03-12 17 4 312 322 10.4314/njtd.v17i4.10