ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY AND ENVIRONMENT 2020-02-11T19:46:27-05:00 Prof. N.A. Aviara Open Journal Systems <p align="justify">The Arid Zone Journal of Engineering, Technology and Environment is peer reviewed journal with the objectives to explore, develop and elucidate the knowledge of Engineering design and technology, to keep Practitioners and Researchers informed on current issues and best practices, as well as serving as a platform for the exchange of ideas, knowledge and expertise among technology researchers and practitioners. AZOJETE is published by the Faculty of Engineering, University of Maiduguri, Nigeria.</p> <p><strong>p-ISSN:</strong> 1596-2490 | <strong>e-ISSN:</strong> 2545-5818</p> <p><strong>PUBLICATIONS:</strong> MARCH, JUNE, SEPTEMBER AND DECEMBER</p> <p>AZOJETE is currently indexed in the following indexing platforms</p> <p><a href=";hl=en&amp;authuser=1" target="_blank" rel="noopener">GoogleScholar</a>, <a href="" target="_blank" rel="noopener">DOAJ</a>, <a href="" target="_blank" rel="noopener">ACADEMIA</a>, <a href="" target="_blank" rel="noopener">ResearchBib</a>, <a href="" target="_blank" rel="noopener">CosmosIF</a>, <a href="" target="_blank" rel="noopener">CiteFactor</a>, &nbsp;Bielefeld University Library, IIJIF, SIS, Cosmos Impact Factor, <a href=";subAction=subjects&amp;publisherID=34&amp;journalID=38287&amp;pageb=1&amp;userQueryID=&amp;sort=&amp;local_page=&amp;sorType=&amp;sorCol=" target="_blank" rel="noopener">JournalTOCs</a>, <a href="" target="_blank" rel="noopener">OAJI</a>,&nbsp; Journal Factor, SPARC Indexing, <a href="" target="_blank" rel="noopener">OpenAIRE</a>, Eurasian Scientific Journal Index, Electronic Journals Library, ISI, Social Science Research Centre Berlin, <a href="" target="_blank" rel="noopener">WorldCat</a>, International Institute of Organized Research (I2OR), StudyLIB,&nbsp; Journal Finder, <a href="" target="_blank" rel="noopener">University of Saskatchewan Library</a>,&nbsp; ScopeMed, Microsoft Academic, <a href=";recordsPage=2" target="_blank" rel="noopener">PKP Index</a>, <a href="" target="_blank" rel="noopener">efita</a>, JournalFinder, <a href="" target="_blank" rel="noopener">Publons</a>, <a href="" target="_blank" rel="noopener">Ghent University Library</a>, University Library of Regensburg, University of Groningen Library, University of Georgia, Berkeley Library University of California, ProQuest, <a href="" target="_blank" rel="noopener">ISSN Portal</a>, <a href="" target="_blank" rel="noopener">PIST</a>, <a href="" target="_blank" rel="noopener">DRJI</a>, <a href="" target="_blank" rel="noopener">TEEAL</a>, <a href="" target="_blank" rel="noopener">Technical University of Braunschweig</a>, <a href=";View=uba&amp;Language=de" target="_blank" rel="noopener">University Library Augsburg.</a> <a href="" target="_blank" rel="noopener">The Leipzig University Library,</a> <a href=";context=L&amp;vid=44HYG_INST:44HYG_VU1&amp;lang=en&amp;search_scope=MyInst_and_CI&amp;adaptor=Local%20Search%20Engine&amp;tab=Everything&amp;query=sub,exact,Agricultural%20Engineering%20,AND&amp;mode=advanced" target="_blank" rel="noopener">London School of Hygiene and Tropical Medicine</a>, <a href="" target="_blank" rel="noopener">EuroPub DASJ</a>, <a href="" target="_blank" rel="noopener">SJIF</a>, <a href="" target="_blank" rel="noopener">Technical University of Braunschweig</a>, <a href="" target="_blank" rel="noopener">EuroPub</a>, <a href=";R=3747465" target="_blank" rel="noopener">Toronto Public Library</a>, <a href="" target="_blank" rel="noopener">EDUINDEX Index of Education</a></p> Analytical, Numerical and Computational Multiscale Modelling Techniques for Heterogenous Materials: A Review 2020-01-14T16:04:16-05:00 O. H. Aliyu <p>This paper reviews the analytical, numerical as well as the computational homogenization multiscale modelling schemes for determining the effective material properties for heterogeneous medium at the macroscopic level. It also looked at the limitations of the analytical homogenization techniques in simulating the effective non linear heterogeneous material behaviours (for example the rapid localization of damage and so on) as well as the advancements of the computational techniques in addressing these limitations. In addition, the possible future trends for the computational technique such as the development of a fully coupled micro-macro computational scheme were also discussed. It was concluded that although, the analytical technique was quite popular and straight forward, its inability to capture rapid localization of damage limited its application and that numerical and computational schemes were able to address these limitations as they relied on the establishment of constitutive relations for the macroscopic problems in a numerical form through which the macroscopic problems were constructed and solved in a nested manner.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Evaluation of Sheanut Shell-Reinforced Automotive Brake Pad 2020-01-14T16:05:20-05:00 V. N. Haruna A. S. Abdulrahman M. S. Abolarin R. A. Muriana <p>For over a century now, asbestos has been used as friction material in the manufacture of brake pads but its use is currently been avoided due to its carcinogenic nature and potential to cause cancer. This study is focused on development of a new brake pad using sheanut shell (SNS) which is an eco-friendly material as the reinforcement and epoxy resin as the binder. Other constituents used are calcium carbonate (CaCO<sub>3</sub>), graphite and aluminium oxide (Al<sub>2</sub>O<sub>3</sub>). Five compositions were formulated with the epoxy resin and reinforcement varied at interval of 5 wt% while CaCO<sub>3</sub>, graphite and Al<sub>2</sub>O<sub>3</sub>&nbsp;remain constant at 30, 10 and 10 wt% respectively. The developed brake pads were subjected to compressive, abrasive and water absorption tests while their densities were also measured. The results showed that the compressive strength, abrasive strength and the density of the samples decreased as the reinforcement content increased while the water absorption rate increased as the reinforcement content increased. The value of the compressive strength ranged from 64.88 – 93.04Mpa, wear rate from 3.13 – 6.25mg/m, water absorption from 0.899 – 2.722% and density from 0.764 – 1.487g/m<sup>3</sup>. The result of this research indicates that SNS particles can be used as a replacement for asbestos in brake pad production.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Prediction of Density and Viscosity of Biodiesel Fuel from Fatty Acid Methyl Ester (FAME) Composition 2020-01-14T16:08:54-05:00 S.O. Jekayinfa A.O. Adebayo M. A. Sulaiman V.O. Ayoola <p>Viscosity and density are important properties that qualify biodiesel fuel to serve as an alternative fuel because all other properties directly or indirectly depend on them. The processes involved in determining the viscosity and density of biodiesel are relatively simple and costly and there are discrepancies in the results obtained due to the differences in the oil composition of the feed-stocks used as against the reported cause of experimental errors. This work aimed at theoretically determining and developing relationship between the density and viscosity of different feed-stocks and the fatty acid methyl ester composition at different temperatures.In the study, density and viscosity data of biodiesel fuels and the composition of FAME were collected from literatures. &nbsp;A linear regression analysis was carried out for density and viscosity on the average values of viscosity and density data obtained at different temperatures range (10°C-40°C) of FAME composition. Equations relating density and viscosity with the percentage composition by weight of FAME of biodiesel fuel were developed. Predicted mean values for kinematic viscosity and density were respectively between 4.31 - 5.64 mm<sup>2</sup>/s and 861.67 – 885.66 kg/m<sup>3</sup>. The developed equations were able to predict with up to 97.1% accuracy for viscosity and 98.5% accuracy for density. The developed equations could effectively predict the quality of biodiesel (viscosity and density) from various feedstocks based on FAME compositions.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Effect of Moisture Content on some Engineering Properties of African Mahogany (Afzelia Africana) Seed 2020-01-14T16:08:05-05:00 N. A. Aviara S. Ekaso Jr O. U. Nwanja <p>Some engineering properties of <em>Afzelia africana</em>, namely axial dimensions, one thousand seed mass, surface area, particle density, bulk density, porosity, angle of repose, static and kinetic coefficients of friction, coefficient of restitution and specific heat were determined as a function of moisture content in the moisture range of 6.1 – 32.3% (d.b). Results showed that in the above moisture range, major, intermediate and minor axial dimensions of the seed increased from 25.4 – 26.2mm, 13.2 – 13.95mm and 10.2 – 11.2mm, respectively. One thousand seed mass, surface area, particle density, porosity, angle of repose, static coefficient of friction, kinetic coefficient of friction and specific heat capacity of the seeds all increased with increase in moisture content. Seed bulk density decreased with increase in moisture content and coefficient of restitution decreased as drop height and moisture content increased. The relationship existing between the engineering properties and seed moisture content, established using regression analysis showed high coefficient of determination. These properties would be useful in the design of <em>Afzelia africana</em>&nbsp;seed handling, storage and processing equipment.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri The Potential of Bioethanol as a Viable Alternative to Fossil Fuels 2020-01-26T08:51:20-05:00 K. O. Rabiu L. K. Abidoye A. T. Oriaje <p>Environmental challenges from fossil fuel emission have global issues and have contributed immensely to climate change. Bioethanol has experienced unprecedented level of attention due to its value as substitute to fossil fuel. Besides being a renewable and sustainable source of energy, it is also efficient, available and environmentally friendly. Global production of bioethanol continues to increase and will probably continue to dominate the alternative fuels market in the next decade. It is important to emphasize that for bioethanol to be a viable alternative, it must have ecological benefits, be economically competitive and its production must be in commercial scales without affecting the food production. This paper explains the problems and possible solutions in the production of bioethanol; since biofuel produces clean energy which can reduce the emission of CO<sub>2</sub> into the atmosphere.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Development of Hydropower Turbines Powered by Dam Overflow 2020-01-26T08:57:29-05:00 O. O. Oyebode J. O. Olaoye <p>The epileptic power supply in most rural areas in Nigeria and its attendant negative impact on the economy of the Nation, Agricultural productivity and huge rural emigration, is a serious source of concern. This necessitated the development of two hydro-power turbines powered by the overflow (which was rather considered a waste) from University of Ilorin (UNILORIN) dam. A portion of the overflow was channeled into a Polyvinyl Chloride&nbsp;(PVC) pipe and the flow rate was calculated to be 0.017m<sup>3</sup>/sec using the bucket method. The change in elevation between the overflow and the point of usage was reported to be 4m. The flow (Q) and Head (h) were typical values for many streams and rivers in different rural areas of Nigeria, hence its suitability and adoption for this study. Two turbines viz: Pelton Wheel (PW) and Cross Flow (CF) were developed and tested. The PW generated a speed of 538.4rpm and a torque of 46.2kNm at off load condition while the CF generated a speed of 330.1rpm and a torque of 39.07kNm at the same condition. During loading – when the alternator had been connected to the turbine - the PW turbine speed and torque became 392.0rpm and 36.5kNm respectively, while that of the CF became 197.7rpm and 25.0kNm respectively. A belt and pulley mechanism was used to deliver the rotational speed to the alternator and this increased the alternator speed from the PW and CF turbines to 1768.6rpm and 879.24rpm respectively. The speed from the PW was enough to power the alternator as the alternator only requires 1500rpm to function optimally. The PW was thus adjudged the most suitable for use.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri A Review of TV White Space Technology and its Deployments in Africa 2020-01-26T09:05:06-05:00 I. Mustapha Mala U. M. Bakura D. Mustapha M. Abbagana <p>The emergence of bandwidth-driven applications in the current wireless communication environment is driving a paradigm shift from the conventional fixed spectrum assignment policy to intelligent and dynamic spectrum access. Practical demands for efficient spectrum utilization have continued to drive the development of TV white space technology to provide affordable and reliable wireless connectivity. It is envisaged that transition from analogue transmission to Digital Terrestrial Television (DTT) creates more spectrum opportunity for TV white space access and regulatory agencies of many countries had begun to explore this opportunity to address spectrum scarcity. To convey the evolutionary trends in the development of TV white space technology, this paper presents a comprehensive review on the contemporary approaches to TV white space technology and practical deployments of pilot projects in Africa. The paper outlines the activities in TV white space technology, which include regulations and standardization, commercial trials, research challenges, open issues and future research directions. Furthermore, it also provides an overview of the current industrial trends in TV white space technology which demonstrates that cognitive radio as an enabling technology for TV white space technology.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Stabilization of Laterite Soil with Eggshell Powder and Sodium Silicate used as fill Material in Road Construction 2020-02-11T19:46:27-05:00 J. A. Oke M. K. Olowoyo <p>The investigation carried out in this paper was to evaluate the effect of eggshell powder and sodium silicate as stabilizers to laterite soil used as fill material for the purpose of constructing light traffic pavement. The laterite soil used in this study was collected from Ikorodu North Local Government Area in Lagos State, Nigeria and treated with eggshell powder (ESP) and sodium silicate (SS) blend in stepped concentrations of 3% ESP + 2% SS, 6% ESP + 4% SS, 9% ESP + 6% SS, 12% ESP + 8% SS and 15% ESP + 10% SS by dry weight of the soil. Results from the tests carried out showed a general improvement on the engineering properties of the laterite treated with ESP and SS blend. Optimum California Bearing Ratio (CBR) tests results for un-soaked and soaked samples were recorded as 51% and 22% at 12% ESP + 8%SS content. Peak Unconfined Compressive Strength (UCS) values of 355 KN/m<sup>2</sup>&nbsp;and 570 KN/m<sup>2</sup> were recorded at 7- and 28-days curing periods respectively at an optimum blend of 12% ESP + 8%SS content. &nbsp;From the results obtained in this research, an optimum blend of 12% ESP and 8% SS using the West African Standard (WAS) compactive effort can be used to stabilize laterite soil material for use as fill material for the construction of light traffic roads. An advantage of applying the ESP is the decrease in the deleterious environmental impact of eggshell waste.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Mechanical and Microstructural Characterization of Alkali-Activated Coconut Shell Ash Mortar 2020-01-26T09:18:23-05:00 K. A. Olonade T. Bello <p>In this paper, potential of alkaline activation of coconut shell ash (CSA) as binder in mortar was investigated. Coconut shells were collected and calcined at temperature ranges between 500 and 900°C at interval of 100 for 30, 60 and 90 minutes to determine optimum burning condition that produces ash of higher silica content. Chemical composition of the ashes was then determined using X-ray Florescence (XRF) technique. Sodium hydroxide (NaOH) of different concentrations of 10, 12, 14 and 16 Molar (M) was used as alkaline activator, while mortar of mix ratio 1:3 was produced, while ratio of the alkali to CSA was of 0.5. &nbsp;Mortar prisms of size 40 mm &nbsp;40 mm &nbsp;160 mm were cast and cured in an oven at a temperature of 80 &nbsp;for 7, 28, 56, 90 and 120 days. Thereafter, flexural and compressive strengths were determined at the end of each curing ages, following standard procedures. Scanning Electron micrographs of the hydrated mortar at 120 days were obtained using scanning electron microscopy (SEM) The results showed the oxide composition did not follow any pattern with increase in temperature but CSA produced at 800&nbsp;for 1h gave the highest combined silica, alumina and ferric oxides above 70%, which is accepted as minimum value for pozzolanic materials. &nbsp;Both compressive and flexural strengths of the activated mortar samples were found to increase with increase in activator concentration up to 14M and decline thereafter. At 120 days, the compressive strength was 13.9 N/mm<sup>2</sup>&nbsp;while the flexural strength was 6.88 N/mm<sup>2</sup>. These values were higher than the strengths recommended by Nigerian Industrial Standard (NIS) for load bearing blocks. It was concluded that activation of CSA with NaOH could be used as binder for non-structural use. The SEM results indicated that mortar made from 14 M had structure that was densely packed compared to other mortar samples produced from other concentrations.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Impact of Different Fine Aggregates on the Compressive Strength of Hollow Sandcrete Blocks 2020-01-26T09:25:20-05:00 S.O. Odeyemi R. Abdulwahab M. A. Anifowose R. J. Ibrahim <p>Sandcrete blocks are walling materials that are made of fine aggregates and cement. Though, sandcrete blocks are being used as building materials in many parts of Nigeria, it has been discovered that many of the blocks produced do not conform to the minimum compressive strength requirement for such blocks. This study, therefore, examined the effect of using four (4) different fine aggregates (quarry dust, river sand, shocking sand and plastering sand) with binder to aggregate mix ratios of 1:6 and 1:4 on the compressive strength of sandcrete blocks. Specific gravity and particle size distribution analyses were conducted on the fine aggregates to determine their properties while water absorption capacity and compressive strength tests were carried out on the hollow sandcrete blocks. Five samples from each aggregate of size 450 mm x 225 mm&nbsp;x 225 mm were moulded and subjected to compressive strength tests. The water absorption capacity results revealed that shocking sand has the highest capacity to absorb water with a value of 8.69 %. River sand, with a value of 6.67 % has the lowest water absorption capacity. The 28th day compressive strength test results of 1.31 N/mm<sup>2</sup>, 1.10 N/mm<sup>2</sup>, 0.78 N/mm<sup>2</sup>&nbsp;and 0.50 N/mm<sup>2</sup>&nbsp;for the sandcrete blocks produced from quarry dust, river sand, shocking sand and plastering sand respectively, with mix ratio 1:6, did not meet the minimum requirement of 2.5 N/mm<sup>2</sup>&nbsp;specified by NIS 87:2007 for non-load bearing walls. However, with mix ratio of 1:4, the compressive strength of 2.52 N/mm<sup>2</sup>&nbsp;and 2.50 N/mm<sup>2</sup>&nbsp;for sandcrete blocks made with quarry dust and river sand respectively met this minimum requirement. It was concluded that only quarry dust and sharp sand at mix ratio 1:4 are suitable in the production of sandcrete blocks.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Effect of Number of Beaters on the Performance of Household Hammer Mill 2020-01-26T09:37:14-05:00 F. A. Oluwole A. Gujja A. K. Abubakar <p>A hammer mill with three different hammers having 2, 4 and 6 beaters was developed and evaluated. Maize and guinea corn were crushed at 3 different angular speeds of the hammer rotations (2600 rpm, 3000 rpm and 3400 rpm). Each beater was fixed on the shaft at a time and machine was started. As soon as the machine reached the required speed, 500g of sample was fed into the crushing chamber through the feed hopper. The final product was collected, weighed. Fuel consumed during the operation and the time taken were recorded. The process was replicated 3 times for both maize and guinea corn using the 3 hammers. The result obtained during the evaluation revealed that the average milling efficiency and specific fuel consumption (sfc) for 6 beaters, 4 beaters and 2 beaters were 83.5 % and 3.8 l/h, 72.47 % and 2.07 l/h and 60.19 % and 0.94 l/h respectively. The average milling efficiency and sfc for maize and guinea corn were 72.18 % and 2.45 l/h and 71.93 %, 2.09 l/h respectively. Number of beaters and angular speed of beaters and their interactions significantly affected the milling efficiency at 5 % level. Number of beaters, angular speed of beaters, sample type and their interactions significantly affected the sfc at 5 % level.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Evaluation of Geotechnical and Structural Performance of Cement-Stabilized Soil with Saw Dust Ash (SDA) 2020-01-26T09:51:00-05:00 C. A. Fapohunda O. O. Amu O. F. Babarinde <p>Availability of good soils for the construction of Civil engineering works is pivotal to the development and progress of any nation. Where good soils are lacking, it is necessary to make the soil fit through soil improvement methods. This study investigates the geotechnical performance of soil stabilized with the blend of cement and saw dust ash (SDA). The blend consists of 9% cement by weight and up to 10% of SDA at interval of 2%. The tests conducted on both stabilized and unstabilized soils samples at three different locations, identified as A, B, and C were: particle size distribution, natural moisture content, Atterberg’s limits, compaction, California Bearing Ratio (CBR) and Unconfined Compression Strength (UCS). The results showed decrease in plasticity index from high to medium, increase in CBR values: 4 – 10% for sample A, 2 – 12% for sample B and 5 – 8% for sample C, and increase in unconfined compression strength values: 45.23 – 65.88 kN/m<sup>2</sup>&nbsp;for sample A, 34.01 – 59.18 kN/m<sup>2</sup>&nbsp;for B and 41.80 – 63.94 kN/m<sup>2</sup>&nbsp;for C. The results of this investigation showed that improvement of soil for construction purpose can be achieved when SDA is applied as a stabilizer in a cement-stabilized soil, up to 6% by weight of cement. Specifically, improved shear stress demonstrated up to 6% replacement is an indication of fitness for application of such soil in the design of footing, especially for columns, where shear stresses usually control the footing thickness.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Effect of Number of Passengers [Loading] on Centre of Gravity of a Three Wheeled Vehicle [Keke-Napep] 2020-01-26T09:45:24-05:00 B. Sunday U. Thomas I. S. Ityokumbul A. Nasir <p>In order to combat insecurity and to reduce the rate of accidents caused by commercial motorcyclist; many States Government in Northern Nigeria have substituted the use of motor cycles commonly known as Okada, with the use of three wheeled vehicle commonly known as keke-napep. The Static and dynamic characteristics of these vehicles are not as those of the usual vehicles. Therefore, the need to know more about the effects loading on these vehicles is highly needed by Nigerians in order to ensure good road and passengers’ safety. This paper uses simple approach to highlight the effects of number of passengers (loading) on the position of Centre of Gravity (CG) of the three wheeled vehicles. It will serve as a measure for ensuring safe riding and reducing road clashes. As the load on the three wheeled vehicle increases from 3505N to 5410N, the Static Stability Factor decreases. This reduces the safety margin against rollover of the three wheeled vehicles compared to those of the four wheeled vehicles. The keke-napep is a rear wheel drive vehicle with rear engine and rear passenger arrangement. It subjects the vehicle to high weight transfer during braking. This causes the change in position of Centre of Gravity and the instability of the three wheeled vehicles. Therefore, it is hereby recommended that the wheelbase, track length, loading space and the Centre of Gravity position should be given a critical consideration during chassis design in order to improve the static and dynamic stability of these vehicles. Also, Components such as the engine and transmission system should be rearranged to obtain a more reliable position of the Centre of Gravity.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Assessment of Workers’ Level of Exposure to Work-Related Musculoskeletal Discomfort in Dewatered Cassava Mash Sieving Process 2020-01-26T12:34:19-05:00 A. A. Ahiakwo K. J. Simonyan A. B. Eke <p>This study was undertaken to assess the level of exposure of processors to work-related musculoskeletal disorder when using the locally developed traditional sieve in the sieving process. Quick ergonomic checklist (QEC) &nbsp;involving the researcher’s and the processors’ assessment using the risk assessment checklist, was used in this assessment and data was obtained from a sample of one hundred and eight (108) processors randomly selected from three senatorial districts of Rivers State. Thirty-six processors from each zone comprising of 14 males and 22 females, were selected., and assessed on the bases of their back, shoulder/arm, wrist/hand and neck posture and frequency of movement during traditional sieving process. The result of the assessment showed that the highest risk of discomfort occurred at the region of the wrist/hand, followed by back, shoulder/arm, and neck. The posture used in the sieving process exposed the processors, not only to the discomfort of pain but also put them at high risk of musculoskeletal disorder at indicated by &nbsp;a high level of percentage exposure of 66% QEC rating. The result indicated a need for immediate attention and change to an improved method that will reduce the discomfort on the body parts assessed. identified parts.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Properties of Asphalt Concrete Containing Waste Foundry Sand (WFS) as Filler Material 2020-01-26T13:13:40-05:00 A. A. Shuaibu H. S. Otuoze A. Mohammed M. A. Lateef <p>The high cost of primary construction materials such as cement, and increase in waste generation due to human activities coupled with environmental concerns has led to the incorporation of wide range of waste materials into asphalt concrete. Waste foundry sand (WFS) which is a by-product of ferrous and non-ferrous metal casting industry, has accumulated in stockpiles and landfills, occupying valuable space and causing nuisance in the environment. Consequently, it is imperative to devise a safe and economical solution to manage and utilize the waste. One way of achieving this is by recycling and using it for asphalt concrete production. This study investigated the strength and durability properties of asphalt concrete containing waste foundry sand (WFS) as alternative filler material in asphalt concrete. Marshall design method was adopted for the sample preparation and testing. Fifteen (15) compacted samples were prepared for strength and volumetric properties testing at varying bitumen contents of 4.5%, 5.0%, 5.5%, 6.0% and 6.5%, in accordance with Asphalt Institute and Nigeria General Specification for Road and Bridges to determine optimum bitumen content (OBC). OBC of 5.5% was obtained and used for the asphalt concrete mixes in the study.&nbsp; Eighteen (18) other briquettes were prepared to determine the optimum WFS content in asphalt concrete necessary for strength and durability of wearing course of flexible pavement. Cement as filler in asphalt concrete was partially replaced with WFS using the obtained OBC in the order of 10%, 20%, 30%, 40%, 50% and 60%. A total of thirty-three (33) standard specimens were prepared. From the Marshall stability-flow and void-density results, the sample prepared with 60% WFS as filler with OBC of 5.5% satisfies the provision of the Nigerian General Specification for Road and Bridges (NGSRB) for use in wearing course of flexible pavement. Based on the analysis of results obtained in this study and a logical comparison made with standard specifications, addition of up to 60% waste foundry sand (WFS) in asphalt concrete would lead to significant conservation of primary construction materials, divert substantial quantities of waste from landfills and present a cheap alternative of filler material necessary for sustainable asphalt concrete construction.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Seasonal Variation in Rates of Dust Fall at Motor Parks of University of Ilorin, Ilorin, Nigeria 2020-01-26T13:22:07-05:00 F. O. Nwosu O. D. Olayinka C. O. Akoshile <p>The enormous vehicular activities on the commercial motor parks of University of Ilorin, Nigeria called for concern as a result of noticeable level of particulate matter in the atmosphere of the area. &nbsp;This study was carried out to indicate the seasonal variation in the rate of dust fall at three motor parks in the permanent site of the University campus by using the single bucket sampling method. The study was carried out for five months each of wet and dry season periods. The sampling sites were First Motor Park (PK1), New Motor Park (PK2) and Clinic Area (Cl). Gravimetric method was used to quantify the soluble, insoluble, volatile matter and ash content of the dust. Volatile matter and ash were the component of insoluble dust and the highest rate of insoluble dust deposition was observed in January (2043.12 ± 41.4 and 284.1 ± 35.5 mg/m<sup>2</sup>/day) for PK2 and Cl and in November (1282.7 ± 64.9 mg/m<sup>2</sup>/day) for PK1 when their respective traffic density (1509.5 ±72.1, 29.8 ± 1.2 and 1000.8 ± 48.3 vehicles per hour) was highest. The highest (32713.0 ± 1290.1 mg/m<sup>2</sup>/day) and lowest (70.6 ± 6.9 mg/m<sup>2</sup>/day) rate of soluble dust deposition in the study were observed at PK1 for September and February respectively which was suspected to be due to increase and decrease in the amount of rain fall. The Pearson Correlation showed that increases in traffic density were correlated with increases in the rate of insoluble dust fall at various sites and the relationship was in the stronger order of PK2 &gt; PK1 &gt; Cl. The motor parks ambient air was highly contaminated with soluble dust in the wet season and insoluble dust in the dry season their being values are more than the recommended 133 mg/m<sup>2</sup>/day.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Prediction Modeling of 28-Day Concrete Compressive Strength using Artificial Neutral Network 2020-01-26T13:30:07-05:00 O.A.U. Uche M.T. Abdulwahab A. Suleiman Y. Ismail <p>Compressive strength of concrete at the age of 28 days is an important parameter for the design of concrete structures and waiting for that length of time to obtain the value can be tasky. This study developed an alternative approach using Artificial Neutral Network (ANN) to estimate or predict the compressive strength of concrete at 28th day from early age results. In the study concrete cubes of mix ratio 1:2:4 were cast with different water-cement ratios (0.4, 0.5, 0.6 and 0.65) and their seventh (7th) and twenty-eighth (28th) day strength were measured in the laboratory. In all, 400 cubes of 150 x 150 x 150mm of 200 sets were subjected to compressive strength test using Avery Denison Universal Testing Machine of 2000 kN load capacity at a constant load application of 15kN/s. ANN model was then developed using the time series tool of ANN in MATLAB 7.12.0 (R2011a) applying back propagation algorithm. Out of the 200 sets of results, 110 sets (55%) were used for the training of the network while 30 sets (15%) were used to validate and 60 sets (30%) to test the network. The result of the crushing test shows that the higher the compressive strength at seventh (7th) day the higher it will be at twenty-eighth (28th) day. The result of the ANN model shows a good correlation between the seventh (7th) day compressive strength and the twenty-eighth (28th) day compressive strength with training and validation correlation coefficients of 0.99751 and 0.99736 respectively. It was also found that the ANN model&nbsp;is quite efficient in determining the twenty-eighth (28th) day compressive strength of concreteas the predicted strength values match very well with those obtained experimentally with a correlation coefficient of 0.99675.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Design, Construction and Performance Evaluation of Chicken De-Feathering Machine 2020-01-28T09:52:41-05:00 M. Abubakar A. Zakariyah A. Usman <p>The demand for poultry meat world-wide has imposed great responsibility on poultry processing industry, and especially in de-feathering operation which is usually achieved manually in Nigeria. Being a core stage of poultry processing, de-feathering when carried out manually attracts low production rate (the number of birds produced per hour), high time consumption and labour intensity. This study was focused on design, construction and performance evaluation of chicken de-feathering machine using locally available materials. The design was based on market weight of chicken. The selected materials used to fabricate the machine were trimmed tyre rubber, sheet metals, angle iron and shaft. The rubber cross section was 20 mm×20mm and were arranged both on the shaft length (50mm, 70mm, 90mm, 110mm, 130mm and150mm in length) and at the wall of the bottom cone (80mm length). The height of the machine was 1400mm and 500mm×500mm square area. The performance evaluation result showed that chicken variety had effect on the de-feathering efficiency, throughput capacity and energy consumption of the machine. Scalding time and scalding temperature did not significantly affect throughput capacity and energy consumption but scalding temperature had significant effect on de-feathering efficiency. Maximum mean throughput capacity of 1034 chickens per hour was obtained at 96 % de-feathering efficiency.</p> 2020-01-28T09:52:41-05:00 Copyright (c) 2020 ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY AND ENVIRONMENT Effect of Moisture Content Variation on Thermo-Physical Properties of Brown Variety Tigernut (Cyperus esculentus) 2020-01-28T10:00:25-05:00 D. D. Usman E. O. Adanu B. G. Jahun K. Ibrahim <p>Knowledge of thermophysical properties is essential to the food processing industries. The properties are useful in modeling of thermal behavior of seeds during processing operations such as frying, baking, boiling fermentation and drying. To this end, the thermo physical properties (bulk density, porosity, surface area, thermal conductivity, thermal diffusivity and specific heat capacity) of brown variety tigernut (<em>Cyperus esculentus</em>) were investigated as a function of moisture content. In this study, thermal conductivity and specific heat capacity were determined by transient state heat transfer (line heat source) and mixture methods respectively, whereas, thermal diffusivity, bulk density, porosity and surface area were determined using formula methods. The evaluation was conducted at 5 moisture levels (20, 25, 30, 35 and 40% w.b) with 5 replications. The thermal conductivity and diffusivity increased from 0.03Wm<sup>-1</sup>k<sup>-1</sup>&nbsp;to 0.13Wm<sup>-1</sup>k<sup>-1</sup>&nbsp;and from 7.24 x 10<sup>-7</sup>m<sup>2</sup>s<sup>-1</sup>&nbsp;to 11.06 x 10<sup>-7 </sup>m<sup>2</sup>s<sup>-1</sup>&nbsp;as the moisture content increased from 20 to 40% respectively. The specific heat increased from 10.55 Jkg<sup>-1</sup>K<sup>-1</sup>&nbsp;to 18.75 Jkg<sup>-1</sup>K<sup>-1</sup>, while the bulk density and surface area showed an increase from 421.40 kg/m<sup>3</sup>&nbsp;to 639.80 kg/m<sup>3</sup>&nbsp;and from 197.26 mm<sup>2</sup>&nbsp;to 413.21 mm<sup>2</sup>&nbsp;as moisture content increased. However, porosity decreased in value from 61.84 to 32.33% with an increase in moisture. Moisture content variation was statistically significant (p&lt;0.05) on all properties. The obtained results will find use in the selection of suitable methods for processing of tigernut products, in a quality assessment of optimal modes of technological processes, and in the development of modern processing and handling equipment.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri An Assessment of some of the Poisonous Plant Species to Animals found in Delta State, Nigeria 2020-01-28T10:09:26-05:00 A.H. Erhenhi E.E. Lemy <p>This study investigated some poisonous plants to animals in three communities viz; Ebor-Orogun in Ughelli North Local Government Area; Kwale in Ndokwa West Local Government Area and Ozoro in Isoko South Local Government Area, all in Delta State, Nigeria. Dried leaves, roots and tubers of Dennettia tripetala, Cola nitida, Dracaena marginata, Cucumis melo, Terminalia catappa, Persea americana, Manihot esculenta, Telfaira occidentalis and Vernonia amygdalina were grounded to coarse powders and 16g of each powder was weighed into a conical flask. &nbsp;Distilled water (120cm3) was added and the content was shaken and kept for 48hours at room temperature. Filtration of the extract was carried out using whatman No1 filter paper and concentrated using vacuum evaporator. Phytochemical analysis was carried out using standard methods. The results revealed that there were nine (9) indigenous plants with poisonous effects to animals as reported by the community dwellers, among the selected plants and these include: D. tripetala, C. nitida, D. marginata and C. melo, T. catappa, P. americana, M. esculenta (tuber), T. occidentalis (root) and V. amygdalina (root). Qualitative analysis showed the presence of alkaloid, anthocyanines, cardiac glycoside, flavonoid, glycoside, phenol, reducing sugar, saponin, saponin, tannin and terpenoid in low, moderate and high level in the plants. The chemical quantification revealed the presence of tannin (26.90%, 22.95%, 27%) in C. melo, D. tripetala and C. nitida, saponin (13%) in N. laewis, cyanogenic glycoside (3.24mg/l, 1.11mg/l) in M. esculenta and V. amygdalina followed by hydrogen cyanide (0.76mg/l, 0.75mg/l, 6.41mg/l) in P. americana, T. catappa and T. occidentalisas the major cause of poisoning in the plants encountered.There is need for evaluation of the effects of these substances on the organs and systems of animals in order to ascertain the actual site of toxicity of these substances.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Review of Agricultural Waste Utilization as Improvement Additives for Residual Tropical Soils 2020-01-29T02:39:18-05:00 K. Ishola O. A. Olawuyi A. A. Bello R. K. Etim P. Yohanna J. E. Sani <p>The development of a nation partially depends on sustainable materials obtained from agricultural products. Increased agricultural products could increase the amount of waste generated yearly. This paper presents a review on the use of agricultural waste with pozzolanic properties (rice husk ash, Locust bean waste ash, Palm oil fuel&nbsp;ash, Banana leaf ash, Bagasse ash, Coconut shell ash, Bamboo leaf ash, Corn cob ash, Cassava peel ash and Palm kernel shell&nbsp;ash) in various geotechnical engineering applications. Interestingly, these wastes were subjected to various laboratory tests such as (particle size distribution, Compaction, Atterberg, unconfined compressive strength (UCS) and California bearing ratio (CBR)) to assess their effectiveness in soil improvement. In all these, the percentages of the materials required for soil improvement were discussed. The reports from various researchers have shown that agricultural waste having pozzolanic properties improves the engineering properties of soil. For instance, palm oil fuel ash (POFA) is mostly used as an admixture in concrete as reported elsewhere. Few studies have been carried out on the use of banana leaf ash and palm oil fuel ash as soil improvement materials. It is recommended that further researches should focus on the possibility of using other agricultural waste from Cocoyam, Yam peel, maize trunk, Cashew and Guava that have limited reporting researches for use as soil improvement materials.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Simulation of Prototype Active Agricultural Solar Dryer with Slit-Type Transpired Solar Collector 2020-01-29T02:44:42-05:00 A. Kuhe J. S. Ibrahim L. T. Tuluen S. A. Akanji <p>This paper presents a functional and easy method for simulation of thin bed drying of maize in an active solar dryer with slit-type transpired collector using TRNSYS software. Thin layer solar drying model written in TRNSYS equation blocks in combination with existing components in the software library were used to build a solar mixed mode dryer system in TRNSYS environment for simulation. Experimental data for thin-bed solar dryer drying of maize obtained at different air mass flow rates of 0.026, 0.033, 0.034, 0.035 and 0.038 kg/sec, respectively, were used for model verification. There was good agreement between simulation results and experimental dryer temperatures for thin-bed solar dryer drying of maize with root mean square error (RMSE) and Nash- Sutcliffe efficiency coefficient (NSE) of 0.95, 0.57, 0.65, 1.15, 1.32 and 0.92, 0.93, 0.92, 0.85, 0.89 respectively for the air mass flowrates investigated. The results further confirmed that TRNSYS software can be a useful tool in the design and optimization of solar dryer systems.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Computational Fluid Dynamics (CFD) Analyses of Energy and Exergy in Thin Layer Drying of Okra (Abelmoschus esculentus) Slices using Centre Shaft Rotary Tray Cabinet (CSRTC) Dryer 2020-01-29T02:53:34-05:00 S. K. Oyeniyi O. S. Olatunbosun A. K. Aremu N. A. Aviara I. J. Iyilade <p>This paper presents a simulation of the drying process of okra (<em>Abelmoschus esculentus</em>) in a Center Shaft (CS) Rotary Tray Cabinet Dryer using three drying temperatures (50, 60 and 70 °C). ANSYS 14.5 Workbench was used to simulate the dryer model in 2D (2 Dimensional). The detail of the CFD simulation was utilized to investigate the energy and exergy of the dryer. The ANSYS Design Modeler was used to model the 2D representation of the dryer and the meshing was done using ANSYS ICEM. ANSYS Fluent CFD solver was then used to calculate the alternative using the normal turbulence-realizable k-epsilon model in a steady-state system with improved wall temperature treatment. The simulation outcome was used in calculating the dryer's exergy and energy analysis based on the thermal efficiency. It was noted that the simulated temperature from the experiment is greater than that of the experiment. The results indicated that the experimental energy utilization (EU), energy utilization ratio (EUR) and energy efficiency increased from 14.1 to 57.93 J/s, 0.15 to 0.20 and 18.89 to 33.98 percent, while the simulated energy utilization ratio increased from 23.91 to 57.68 J/s, 0.19 to 0.20 and 26.21 to 33.40 percent, respectively, and as the drying air temperature increased from 50 °C to 70 °C. Experimental exergy inflow, outflow, exergy loss and exergy efficiency increased from 4.01 J/s to 6.98 J/s, 1.83 J/s to 1.9 J/s, 3.18 J/s to 5.07 J/s and 21 to 27%, while simulated air temperatures increased from 5.01 J/s to 7.49 J/s, 1.33 J/s to 2.20 J/s, 3.66 J/s to 5.29 J/s and 27 to 29% respectively with respect to the drying air temperature range (50–70 °C). Model equations were derived from the plotted graphs to express the energy and exergy parameters as a function of drying temperature.</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Effects of Soil Properties and Operational Variables on the Compactibility of a Sandy Loam Soil 2020-01-29T03:01:06-05:00 D. Audu O. S. Balogun F. A. Adeniji Y. Musa <p>The evaluation of an empirical equation for the determination of degree of compaction of a sandy loam soil was carried out using seven soil physical properties and four compaction operational variables. The soil used was obtained from a borrow pit in Gombe. Five levels of compactive effort, E/A, using a drop-weight type compactor varying from 107.91 to 539.55 Nm was used to compact each of seven pairs of embankment and slice thicknesses (Z, z respectively) with Z varying from 210 to 450 mm and z from 30 to 210 mm. The developed empirical equation, π<sub>1</sub>&nbsp;= Gπ<sub>2</sub><sup>k</sup>&nbsp;in which π1 is the dimensionless degree of compaction and π<sub>2</sub>&nbsp;is a dimensionless combination of the soil properties and the compaction operational variables, has a very high coefficient of determination, r<sup>2</sup>&nbsp;varying from 98.8% to 98.9%. G and k are each polynomial functions of compactive effort per loading, e<sub>L</sub>. that is, G = α<sub>G</sub>e<sub>L</sub><sup>2</sup>+β<sub>G</sub>&nbsp;e<sub>L</sub>&nbsp;+ λ<sub>G</sub>&nbsp;and k=α<sub>k</sub>e<sub>L</sub><sup>2</sup>+β<sub>k</sub>e<sub>L</sub>+ λ<sub>k</sub>. The values of the respective α, β and λ are highly statistically significant at 99.95 confidence level. The “dependent” variables (G and k) are highly correlated at 99.95% confidence level of statistical significance with the “independent” variable (e<sub>L</sub>). The multivariate expression of the degree of compaction obtained in this study shows that compaction depends, not only on cumulative compactive effort, E/A, but also on the compactive effort per loading (e<sub>L</sub>), embankment and slice thicknesses (Z and z respectively) as well as on easy-to-measure soil properties (i.e. soil texture, soil uniformity coefficient, antecedent soil moisture and antecedent bulk density).</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri Drag Reduction with Polymer Mixtures in Pipes of Different Diameters 2020-01-29T03:07:58-05:00 M. M Gimba L. C. Edomwonyi-Otu N. Yusuf A. Abubakar <p>Transporting crude oil and other fluid in pipelines of different sizes over long distances in process industries require high amount of energy which results to high cost of installing pumping stations and maintenance. Addition in part per million (ppm) of high molecular weight polymeric solution reduce such cost. The effect of pipe diameter, oil input volume fraction and flow rate (superficial velocity) on drag reduction (DR) in horizontal oil-waterflows was investigated in unplasticised polyvinylchloride (uPVC) horizontal pipe with two different pipe diameters (0.012 and 0.02 m IDs). The two liquids used were diesel oil (ρ = 832 kg/m<sup>3</sup>, µ = 1.66 cP) and water (ρ = 1,000 kg/m<sup>3</sup>, µ = 0.89 cP) as test fluids at ambient conditions (25°C, 1 atm). Partially hydrolyzed polyacrylamide (HPAM; magnafloc 1011), polyethylene oxide (PEO) and Aloe Vera Mucilage (AVM) separately, as well as mixture of HPAM-AVM and PEO-AVM at different oil input volume fraction (δ<sub>o</sub>; 0,0.25, 0.5, 0.75 and 1) and flow rate (Q; 0.65, 1.28, 1.90 and 2.46 m<sup>3</sup>/hr) were used. The master solution of 2,000 ppm, 2,000 ppm and 20,000 ppm for HPAM, PEO and AVM respectively and their respective mixtures were used to achieve the required concentrations. Mercury U-tube manometer was used to measure the pressure drop. DR of 62%, 65%, 54% for HPAM, PEO and AVM; 69 and 71% for HPAM-AVM and PEO-AVM respectively at mixing ratio of 3:1 and 1:19 in 0.012 m ID. Also, DR of 58%, 62%, 43% for HPAM, PEO and AVM; 67% and 68% for HPAM-AVM and PEO-AVM respectively in 0.02 m ID were obtained at the same condition. The pressure drops observed in the smaller pipe (0.012 m ID) was higher than that of the larger pipe diameter (0.02 m ID). From the experimental results, DR decreased with increase in the pipe diameter at the same conditions. This result implies that, DR in oil-water pipeline flow is a function of oil input volume fraction, superficial velocity and pipe diameter</p> 2019-09-02T00:00:00-04:00 Copyright (c) 2019 Faculty of Engineering, University of Maiduguri