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> en-US <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> (Dr. M. F. Akorede) (Professor A. A. Adedeji) Thu, 29 Oct 2020 18:24:23 +0000 OJS 60 Optimisation of Artificial Lifts Using Prosper Nodal Analysis for BARBRA-1 Well in Niger Delta <p>Hydrocarbon exploration basically requires effective drilling and efficient overpowering of frictional and viscosity forces. Normally, frictional power losses occur in deep well systems and it is essential to analyse each component of any well system to determine where exactly pressure is lost, and this can be done using Nodal Analysis. In this study, nodal analysis has been carried out with the use of PROSPER, a software for well performance, design and optimisation. Artificial lifts can then be used to solve the problem of frictional power losses. To increase the production of Barbra 1 well in the Niger Delta and hence extend its functional life, we have applied nodal analysis. Modelling results for three artificial lift methods; continuous gas lift, intermittent gas lift and electrical submersible pump were found to be 1734.93 bbl/day, 451.50 bbl/day and 2869 bbl/day respectively. The output from the well performance without artificial lift was 1370.99 bbl/day by applying Darcy’s model. Meanwhile, the output from the well without artificial lift is 89.90 bbl/day when aided with productivity index (PI) entry, the normal model for intermittent gas lift. Hence, from the comparative analysis of the results obtained from this study, it was deduced that when artificial lifts are employed, the well output increases significantly from 1370.99bbl/day to 2869 bbl/day (electrical submersible pump). This study concludes that wells such as Barbra 1 are good candidates for artificial lift, and this is evidenced by increasing productivity.</p> <p><strong>Keywords</strong>: Production optimisation, nodal analysis, prosper simulator and barbra well.</p> Tega Odjugo, Yahaya Baba, Aliyu Aliyu, Ndubuisi Okereke, Lekan Oloyede, Olabisi Onifade Copyright (c) Thu, 29 Oct 2020 00:00:00 +0000 Experimental Investigation of Temperature Effects on Low Salinity Enzyme Enhanced Oil Recovery Process <p>In this paper, the effect of temperature on low salinity brine and combined low salinity enzyme oil recovery processes in sandstone rock sample was experimentally investigated. The core flooding displacement tests were conducted with the injection of the enzyme in post-tertiary mode after secondary high salinity brine and tertiary low salinity brine injection processes. Effluents analyses of each of the flooding were carried out and used to evaluate the effect of temperature on rock-fluid interactions and enhanced oil recovery processes. The results showed that tertiary low salinity brine injection and post-tertiary enzyme injection increased recovery by 2.4-8.72% over the secondary high salinity brine flooding at 25 oC. Also, increase in oil recovery (0.57-13.18%) was observed with increase in the system temperature from 25 oC to 70 oC. Furthermore, the effluent of the 70 oC flooding was associated with the earliest low salinity brine ionic breakthrough front at 10 injected pore volume, while the 25 oC flooding breakthrough front occurred at 22 pore volume. However, no obvious effect of temperature on pH of the effluents was observed with all the floodings, but temperature effects were observed with the conductivity and ionic concentrations of all the effluents as evident by varied breakthrough times. Hence, the observed increased recovery in this study is attributable to combined effects of electric double-layer expansion, oil viscosity reduction and interfacial tension reduction. This novel study of the combined low salinity enzyme injection process is significant for the design of enzyme enhanced oil recovery processes.</p> <p><strong>Keywords</strong>: Enhanced oil recovery, enzyme, sandstone, low salinity, core flooding, temperature.</p> Tinuola H. Udoh Copyright (c) Thu, 29 Oct 2020 00:00:00 +0000 Mobile Robot Path Planning in an Obstacle-free Static Environment using Multiple Optimization Algorithms <p>This article presents the implementation and comparison of fruit fly optimization (FOA), ant colony optimization (ACO) and particle swarm optimization (PSO) algorithms in solving the mobile robot path planning problem. FOA is one of the newest nature-inspired algorithms while PSO and ACO has been in existence for a long time. PSO has been shown by other studies to have long search time while ACO have fast convergence speed. Therefore there is need to benchmark FOA performance with these older nature-inspired algorithms. The objective is to find an optimal path in an obstacle free static environment from a start point to the goal point using the aforementioned techniques. The performance of these algorithms was measured using three criteria: average path length, average computational time and average convergence speed. The results show that the fruit fly algorithm produced shorter path length (19.5128 m) with faster convergence speed (3149.217 m/secs) than the older swarm intelligence algorithms. The computational time of the algorithms were in close range, with ant colony optimization having the minimum (0.000576 secs).</p> <p><strong>Keywords</strong>:&nbsp; Swarm intelligence, Fruit Fly algorithm, Ant Colony Optimization, Particle Swarm Optimization, optimal path, mobile robot.</p> C.O. Yinka-Banjo, U. Agwogie Copyright (c) Thu, 29 Oct 2020 00:00:00 +0000 Diversity Control in Evolutionary Computation using Asynchronous Dual-Populations with Search Space Partitioning <p>Diversity control is vital for effective global optimization using evolutionary computation (EC) techniques. This paper classifies the various diversity control policies in the EC literature. Many research works have attributed the high risk of premature convergence to sub-optimal solutions to the poor exploration capabilities resulting from diversity collapse. Also, excessive cost of convergence to optimal solution has been linked to the poor exploitation capabilities necessary to focus the search. To address this exploration-exploitation trade-off, this paper deploys diversity control policies that ensure sustained exploration of the search space without compromising effective exploitation of its promising regions. First, a dual-pool EC algorithm that facilitates a temporal evolution-diversification strategy is proposed. Then a quasi-random heuristic initialisation based on search space partitioning (SSP) is introduced to ensure uniform sampling of the initial search space. Second, for the diversity measurement, a robust convergence detection mechanism that combines a spatial diversity measure; and a population evolvability measure is utilised. It was found that the proposed algorithm needed a pool size of only 50 samples to converge to optimal solutions of a variety of global optimization benchmarks. Overall, the proposed algorithm yields a 33.34% reduction in the cost incurred by a standard EC algorithm. The outcome justifies the efficacy of effective diversity control on solving complex global optimization landscapes.</p> <p><strong>Keywords</strong>: Diversity, exploration-exploitation tradeoff, evolutionary algorithms, heuristic initialisation, taxonomy.</p> H.A. Bashir Copyright (c) Thu, 29 Oct 2020 00:00:00 +0000 Cost Reduction of Fluid Catalytic Cracking Unit in Kaduna Refining and Petrochemical Company using Pinch Technology <p>Pinch technology is one of the most powerful methodologies of process integration that allows industries to increase their profitability through reductions in energy, water and raw materials consumption. In this study, reduction in the total annual cost of heat exchanger network (HEN) of Fluid Catalytic Cracking (FCC) unit in Kaduna Refining and Petrochemical Company (KRPC), Kaduna was determined. With the help of pinch technology, the reduction was achieved by first determining optimum minimum temperature difference by trading off energy cost and capital cost targets as a function of minimum temperature difference. Thereafter, the total annual cost obtained at the optimum minimum temperature difference was compared with total annual cost of existing design. The results of the analysis showed that the optimum minimum temperature difference was 12℃, the total annual costs of the existing design and the optimum-minimum-temperature-difference based cost were $8.7 and $7.1 Million respectively. This amounted to percentage reduction in the total annual cost of 18.4% which means that about $1.6 Million would been saved annually using the optimum minimum temperature difference to design the HEN of the FCC unit.</p> <p><strong>Keywords</strong>: Pinch technology, FCC unit, Cost targeting, Area targeting, Trade-off</p> Abdulkareem Abubakar Copyright (c) Thu, 29 Oct 2020 00:00:00 +0000 Effect of Changing Cement Grade on the Properties of Structural Concrete <p>Many research efforts have been carried out, in a quest to produce mix design information that will guide the concrete and construction industry on how to achieve different concrete strengths, using the different grades of cement available. This is with a view to arresting the rampant collapse of buildings in Nigeria. The work presented in this paper is the result of investigation carried out to determine effects of changing cement grade, while casting a structural member, on the strength behaviour of the concrete. Two types of cement grades: 32.5 R and 42. 5 R were used for this research. In this investigation, the chemical and physical properties of the cement were determined. Consistency and setting times of mortar specimens from the two cement grades were also determined. Concrete samples made from the two cement grades 32.5 R and 42.5 R were evaluated for workability, density, compressive and tensile strengths at water/cement ratios of 0.40, 0.50 and 0.60. The results showed that the cement grade 42.5 consistently developed higher densities at all the water/cement ratios considered. This may be as a result of unforeseen additional dead load at the design stage, which would now amount to underestimation of dead load and thus design load. The results also showed that at higher water/cement ratios, the cement grade 42.5 R has densities exceeding the 2400 kg/m3 recommended by BS 8110. Furthermore, the concretes produced with cement grades of 32.5 R and 42.5 R have different strength development pattern and developed different 28-day compressive strength. Thus, it can be concluded that the action of changing the cement grade during concreting, for the same structural member is not supported by the national code, and will not result in safe and durable concrete.</p> <p><strong>Keywords</strong>: Cement grades, Compressive strength, Density, Portland limestone cement, Tensile strength, Workability</p> C.A. Fapohunda, B.I. Famodimu, B.C. Adigo, A.S. Jeje Copyright (c) Thu, 29 Oct 2020 00:00:00 +0000 Effect of Tillage Practices on Selected Engineering Properties of Cassava (<i>Manihot esculenta</i>) Tubers <p>The main objective of this study was to determine the influence of tillage practices on selected engineering properties of cassava tubers. Two field tests were conducted between May 2014 to April 2015 and May 2015 to April 2016. Eight tillage practices utilized for the experiment were coded as; Ploughing + Harrowing (A), Ploughing + Harrowing + Ridging (B), Manual Ridging (C), Minimum Tillage (D), Ploughing + Harrowing + Manual Digging to a depth of 30 cm + Sawdust of 10 cm depth set at the base (E), Ploughing + Harrowing + Ridging + Sawdust of 10 cm depth set at the base (F), Manual Ridging + Sawdust of 10 cm depth put at the base (G) and Manual Digging to a depth of 30 cm + Sawdust of 10 cm depth put at the base (H). TMS 0581 improved cassava variety and two fertilizer rates 622.50 kg/ha and control were used. Randomized Complete Block Design was used. The experiment was 8x2x1 factorial combinations in split-split plot design with three replications. The effect of different treatments on selected engineering properties of cassava tubers were determined. The results showed that Ploughing + Harrowing (A) tillage practice was significantly different from other tillage practices and gave the most suitable selected engineering properties of size 10.53±0.64<sup>c</sup> cm, surface area 371.15±45.53<sup>bc</sup> cm<sup>2</sup>, sphericity 39.26±1.74a cm, roundness 21.40±3.29<sup>ab</sup> , bulk mass 21.43h kg, coefficient of static friction 2.73±0.06<sup>abc</sup>, compressive strain at break of 2.16±0.03<sup>e</sup> mm/mm, compressive load at break of 11698.90±178.71<sup>f</sup> N, compressive stress at break of 2.72±0.04<sup>d</sup> MPa, energy at break of 191.62±2.93<sup>e</sup> J, modulus automatic of 1.89±0.031<sup>c</sup> MPa, followed by F, G, D, C, E, H and B tillage practices respectively. The study had provided some engineering properties for engineers to develop efficient agricultural machines for handling and processing of fresh cassava tubers.</p> <p><strong>Keywords</strong>: Evaluation, influence, tillage practices, engineering properties, cassava tubers.</p> O.A. Adetola, O. J. Olukunle, A.P. Olalusi, O.O. Olubanjo Copyright (c) Thu, 29 Oct 2020 00:00:00 +0000 Evaluating the Quality Assurance and Control of Hot-Mix Asphalt from Selected Plants in South West, Nigeria <p>Roads are essential necessity of every nation and it is possible that even with proper designs, the roads might not be constructed to the design standard due to poor quality assurance and control resulting in poor pavement quality. This study presents experimental results carried out on various hot - mix asphalt (HMA) samples obtained across different Asphalt plants in South West Nigeria. This was done to determine the extent to which the HMA used in the construction and rehabilitation of Nigerian roads affect their service life. Six samples of the asphalt binder (bitumen) were obtained from each plant over a period of six months and tested. The tested properties were assessed based on the level of conformance with the specifications and requirements from the FMWH General Specification (Roads and Bridges). The results revealed that HMA from plant B had a specific gravity of 1.01, penetration of 65.00 mm, softening point of 53 <sup>o</sup>C, flash point of 237.00 <sup>o</sup>C, peak Marshall Stability of 18.25 kN, flow of 3.87 mm and voids in total mixture peak value of 5.08 %. HMA from plant E had a specific gravity of 1.03, penetration of 65.00 mm, softening point of 51 <sup>o</sup>C, flash point of 239.00 <sup>o</sup>C, peak marshall stability of 18.26 kN, flow of 3.67 mm and voids in total mixture peak value of 4.99 % and these were adjudged the best in conformance with the FMWH specifications. Adequate monitoring of HMA quality for either binder or wearing courses by carrying out quality control and assurance tests is thereby recommended as it affects pavement durability and performance.</p> <p><strong>Keywords</strong>: Hot-mix asphalt, quality assurance, quality control, marshall stability, flow test</p> A.O. Olutaiwo, A. Adanikin Copyright (c) Thu, 29 Oct 2020 00:00:00 +0000 Rainfall Intensity Analysis for Synoptic Stations in Northern Nigeria <p>With the large inter-annual variability of rainfall in Northern Nigeria, a zone subject to frequent dry spells which often result in severe and widespread droughts, the need for intense study of rainfall and accurate forecast of rainfall intensity duration frequency (IDF) curves cannot be over emphasized. The Intensity Duration Frequency relationship is a mathematical relationship between the rainfall intensity and rainfall duration for given return periods. Using a subset of the network of fifteen continuous auto recording rain gauges available in Northern Nigeria, a total of seven different time durations ranging from 12 minutes to 24 hours were developed for return periods of 2, 5, 10, 25, 50 and 100 years. The maximum data series so obtained was fitted to Gumbel’s Extreme Value Type 1 distribution. Linear Regression Analysis was then used to obtain the intensity-duration relationships for the various locations from which Intensity-Duration Frequency (IDF) curves were generated using Microsoft Excel for various return periods.</p> <p><strong>Keywords</strong>:&nbsp; Extreme rainfall, intensity, duration, frequency, Northern Nigeria</p> S.O. Oyegoke, A.S. Adebanjo, H.J. Ododo Copyright (c) Thu, 29 Oct 2020 00:00:00 +0000 Thermodynamic and Optimization Studies of Castor Leaf Extract as Corrosion Inhibitor on Stainless Steel (301) <p>Inhibition of stainless steel corrosion in acidic medium with castor leaf extract was studied using the Gravimetric measurement. The mechanisms of inhibition, influence of temperature on inhibition efficiency and weight loss were determined for temperature range 40 <sup>o</sup>C – 80 <sup>o</sup>C at 7 hours&nbsp; immersion time. An increased in temperature showed a decreased in the inhibition efficiency of the castor leaf extract which resulted to increase in weight loss of the stainless steel. The value of rate constant for the corrosion process ranges from 0.333 – 1.225 hr<sup>−1</sup>, this is seen to be directly relative to the inhibitor concentrations. Activation energy, enthalpy of activation, and entropy values ranges from 74.000 - 136.377 kJ/mol, 71.820 – 133.620 kJ/mol, and 9.860 – 178.110 J/molK respectively. Rise in activation energy with inhibitor concentration confirmed physisorption adsorption mechanism for stainless steel surface corrosion. In order to obtain the optimum weight loss, optimization of the process variables was carried out using the Box – Behnken Design plan and desirability function of response surface methodology (RSM). Four parameters were varied viz; time of immersion, HCl concentration, inhibitor’s concentration, and temperature alongside their effects on weight loss of the stainless steel were verified. The optimal conditions predicted from the second order quadratic model were time (9.10 hours), HCl concentration (3.97 M), concentration of inhibitor (240.90 ppm), and temperature (78.67 <sup>o</sup>C) with 2.978 g as the weight loss. Statistically, the results showed that 95.03% of the variation in total weight loss of stainless steel can be connected to the experimental variables examined.</p> <p><strong>Keywords</strong>: Weight loss, activation parameters, adsorption, optimization, stainless steel, castor leaf</p> A.O. Okewale, A.T. Adebayo Copyright (c) Thu, 29 Oct 2020 00:00:00 +0000