ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY AND ENVIRONMENT https://azojete.com.ng/index.php/azojete <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> 1596-2644 | <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="https://scholar.google.com/citations?user=M32TLtAAAAAJ&amp;hl=en&amp;authuser=1" target="_blank" rel="noopener">GoogleScholar</a>, <a href="https://doaj.org/toc/2545-5818?source=%7B%22query%22%3A%7B%22filtered%22%3A%7B%22filter%22%3A%7B%22bool%22%3A%7B%22must%22%3A%5B%7B%22terms%22%3A%7B%22index.issn.exact%22%3A%5B%222545-5818%22%5D%7D%7D%2C%7B%22term%22%3A%7B%22_type%22%3A%22article%22%7D%7D%5D%7D%7D%2C%22query%22%3A%7B%22match_all%22%3A%7B%7D%7D%7D%7D%2C%22size%22%3A100%2C%22_source%22%3A%7B%7D%7D" target="_blank" rel="noopener">DOAJ</a>, <a href="https://unimaid.academia.edu/AZOJETEUNIMAID" target="_blank" rel="noopener">ACADEMIA</a>, <a href="http://paper.researchbib.com/view/issn/1596-2490/9/1" target="_blank" rel="noopener">ResearchBib</a>, <a href="http://cosmosimpactfactor.com/page/journals_details/2486.html" target="_blank" rel="noopener">CosmosIF</a>, <a href="https://www.citefactor.org/journal/index/17181/arid-zone-journal-of-engineering-technology-and-environment#.XhqbMb5KjIU" target="_blank" rel="noopener">CiteFactor</a>, &nbsp;Bielefeld University Library, IIJIF, SIS, Cosmos Impact Factor, <a href="http://www.journaltocs.ac.uk/index.php?action=browse&amp;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="http://oaji.net/journal-detail.html?number=4371" target="_blank" rel="noopener">OAJI</a>,&nbsp; Journal Factor, SPARC Indexing, <a href="https://explore.openaire.eu/search/dataprovider?datasourceId=openaire____::b36832d2fecd50a7f78fa9fb2e565f16" target="_blank" rel="noopener">OpenAIRE</a>, Eurasian Scientific Journal Index, Electronic Journals Library, ISI, Social Science Research Centre Berlin, <a href="https://www.worldcat.org/title/arid-zone-journal-of-engineering-technology-and-environment/oclc/71193836?referer=tag_list_view" target="_blank" rel="noopener">WorldCat</a>, International Institute of Organized Research (I2OR), StudyLIB,&nbsp; Journal Finder, <a href="https://library.usask.ca/ejournals/view.php?id=3710000001424309" target="_blank" rel="noopener">University of Saskatchewan Library</a>,&nbsp; ScopeMed, Microsoft Academic, <a href="https://index.pkp.sfu.ca/index.php/browse/index/2370?sortOrderId=5&amp;recordsPage=2" target="_blank" rel="noopener">PKP Index</a>, <a href="https://www.efita.org/Environment-and-Nature/Energy/Arid-Zone-Journal-of-Engineering-Technology-and-Environment-details-31363.html" target="_blank" rel="noopener">efita</a>, JournalFinder, <a href="https://publons.com/journal/60407/arid-zone-journal-of-engineering-technology-and-en" target="_blank" rel="noopener">Publons</a>, <a href="https://lib.ugent.be/catalog/ejn01:3710000001424309" 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="https://portal.issn.org/resource/ISSN/2545-5818" target="_blank" rel="noopener">ISSN Portal</a>, <a href="http://www.pist.tn/record/22547?ln=en" target="_blank" rel="noopener">PIST</a>, <a href="http://olddrji.lbp.world/JournalProfile.aspx?jid=2545-5818" target="_blank" rel="noopener">DRJI</a>, <a href="https://teeal.org/journals" target="_blank" rel="noopener">TEEAL</a>, <a href="https://katalog.ub.tu-braunschweig.de/vufind/Record/DOAJ000069043" target="_blank" rel="noopener">Technical University of Braunschweig</a>, <a href="https://opac.bibliothek.uni-augsburg.de/TouchPoint/start.do?Query=1035%3D%22BV043983955%22IN%5B2%5D&amp;View=uba&amp;Language=de" target="_blank" rel="noopener">University Library Augsburg.</a> <a href="https://katalog.ub.uni-leipzig.de/Record/0-875829732" target="_blank" rel="noopener">The Leipzig University Library,</a> <a href="https://discover.lshtm.ac.uk/discovery/fulldisplay?docid=alma991000529439703736&amp;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="https://europub.co.uk/journals/4286" target="_blank" rel="noopener">EuroPub DASJ</a>, <a href="http://sjifactor.com/passport.php?id=19195" target="_blank" rel="noopener">SJIF</a>, <a href="https://katalog.ub.tu-braunschweig.de/vufind/Record/DOAJ000069043" target="_blank" rel="noopener">Technical University of Braunschweig</a>, <a href="https://europub.co.uk/journals/4286" target="_blank" rel="noopener">EuroPub</a>, <a href="https://www.torontopubliclibrary.ca/detail.jsp?Entt=RDM3747465&amp;R=3747465" target="_blank" rel="noopener">Toronto Public Library</a>, <a href="https://www.eduindex.org/2017/11/arid-zone-journal-of-engineering.html?m=1" target="_blank" rel="noopener">EDUINDEX Index of Education</a></p> FACULTY OF ENGINEERING, UNIVERSITY OF MAIDUGURI, NIGERIA en-US ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY AND ENVIRONMENT 1596-2644 <p>Copyright of the paper named above is hereby assigned and transferred to the Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria.</p> Assessment of Regulation Compliance and Quality of Sachet Water Factories in Ibadan North Local Government, Oyo State, Nigeria https://azojete.com.ng/index.php/azojete/article/view/586 <table> <tbody> <tr> <td> <p><em>Provision of clean drinking water is one of the basic human necessities for healthy livelihood. In Nigeria, many people relied on sachet waters as an alternative source of clean drinking water. However, complaints abound regarding lack of proper water quality standard being used which is a major health concern. This study assessed the regulatory compliance of some sachet water production companies and water quality standard in Ibadan North Local Government Area, Oyo State, Nigeria. Questionnaires were administered on factory’s organisational structure and staffing; facilities and equipment; water treatment processes and sanitation practices, Also, Sachet water samples were analysed for the contaminants of Turbidity, Colour, Odour, pH, Nitrate, Chloride, Iron, Electrical conductivity and E-coli count. From the questionnaire analysis, the adherence level with the regulations was poor as majority (60%) of the sachet water factories have poor organisational structure and only 33% have adequate facilities and equipment. However, water quality analysis showed that most of the sachet water parameters tested were within the standard range except for pH values and E Coli count which majority (70%) falls below standard for both. The study concludes that most sachet water brands produced are unsafe for human consumption. There is need for proper monitoring by relevant agencies towards ensuring sachet water factories continuously complied with standard operations for better public health in the study area</em><em>.</em></p> </td> </tr> </tbody> </table> <p>&nbsp;</p> O. R. Durowoju A. Desogan M. Mustapha S. A. Waziri U. A. Ibrahim Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 169 182 Design, Analysis and Construction of an Impressed Current Electric Device for Cathodic Protection https://azojete.com.ng/index.php/azojete/article/view/592 <p><em>This paper aimed at designing, analyzing and fabricating an impressed current electric device. Cathodic protection is a means to prevent corrosion by applying a flow of electrical current from an external source (anode) through the environment and to the metallic structure that is being protected. The protective current changes the environment around the metal thus halting the corrosion reaction. Cathodic protection is used to prevent corrosion in a wide range of applications where the structure being protected is surrounded by an environment that allows current flow. The impressed current cathodic protection systems have the benefit of using an external power supply to drive current. The study used sea water as electrolyte with locally constructed transformer rectifier and to select a proper material for the construction so as to illustrate the effect and how the impressed current system functions. The general performance evaluation was found that the device has a net driving potential of 10.5V and a life expectancy of 128 years of the anode. In conclusion, the construction was successful and easy to operate which can be used to protect metal structure against corrosion.</em></p> A. A. Hammajam M. A. Ibrahim M. K. Adam Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 183 196 An Independent Framework for Off-Grid Hybrid Renewable Energy Design Using Optimal Foraging Algorithm (OFA). https://azojete.com.ng/index.php/azojete/article/view/587 <table> <tbody> <tr> <td> <p><em>The rapidly increase in electrical energy demand from residential, commercial and industrial sectors is one of the major challenge in power system, especially in the current period of high oil prices, steadily reducing energy sources and increased concerns about environmental pollution. Renewable energy is considered as one of the solution to this increase in power demand. The conventional method of power system cannot meet the power demand for many reasons such as environmental effects, location of the consumer, price of fuel and others. This paper presents the design of an off-grid Hybrid Renewable Energy System (HRES) for electrification of a typical remote area. The designed hybrid system consists of three different configurations of PV/Battery, Wind/Battery and PV/Wind/Battery systems. The system components are modelled and the objective function is designed as a function of total annualized cost of the system subject to some constraints binding the decision variables. The total annual cost is formulated as a function of annual capital cost and annual maintenance cost of the system subject to some operational constraints. In order to determine the optimal number of the decision variables that would satisfy the load demand in the most cost effect manner, Optimal Foraging Optimization (OFA) algorithm was used. Finally, a simulation experiment shows that </em><em>the total annual cost obtained by each algorithm for the PV/Battery system is $</em><em>9,340.42 or N3,876,274.30, $9,446.77 or N3,920,409.55</em><em> and $</em><em>10,076.34 or N4,181,681.1 for OFA, GA and PSO respectively. For the Wind/Battery configuration, the total annual cost obtained by OFA, GA and PSO are $17,508.20 or N7,265,903, $12,493.27 or N 5,184,707.05 and $16,535.93 or N6,862,410.95 respectively. Similarly, the PV/Wind/Battery configuration showed that the OFA, GA and PSO obtained an annualized cost of $15,926.07 or N6,609,319.05, $18,167.09 or N7,539,342.35 and $16,535.93 or N6,862,410,95 respectively. From the results obtained by OFA are compared with that of Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) algorithm. Results showed that all the algorithm can efficiently size the hybrid system with OFA obtaining the most economical design. Therefore, for economically and efficiently electrification of a remote area in Abuja using an off-grid hybrid renewable energy system, GA optimization algorithm is recommended for wind/Battery system and OFA optimization algorithm is recommended for PV/Wind/Battery system.</em></p> </td> </tr> </tbody> </table> <p>&nbsp;</p> M. M. Muhammad J. Usman I. Mustapha M. U. M. Bakura A. T. Salawudeen Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 197 208 Numerical Analysis of a Micro Horizontal Axis Wind Turbine Tower Under Extreme Loads https://azojete.com.ng/index.php/azojete/article/view/588 <p><em>One of the major challenges in the development of horizontal axis wind turbine is the selection of appropriate and cost effective tower that will elevate the rotor meters above the ground for wind energy harvest. In this work a tubular structural steel material having an external diameter of 0.1 m, internal diameter of 0.092 m and height of 10 m was selected based on cost, mechanical properties and market availability for the tower. Response of this tower material due to simultaneously applied extreme static, dynamic and aerodynamic loading conditions was analyzed in terms of frequency of vibration, deformation and stress using the numerical code COMSOL Multi-physics 5.2. Three dimensional model of the structural steel tower was developed and boundary conditions defined in the numerical code’s model wizard interface. The tower was considered as a cantilever and a static load of 2128.77 N was applied at 10 m height in the </em> <em>&nbsp;plane.&nbsp; Dynamic load of 413.96 N was applied on the tower in the x,y,z planes and an aerodynamic load of 4967.58 N&nbsp; was applied as uniformly distributed loads in the x plane. Extra fine regular quadrilateral mesh was generated for the computation. Frequency response result of the transfer function at 110 GHz excitation shown in terms of electric field norm was uniformly distributed at the outer boundary layer of the tower with a minimum value of 3.7 x 10<sup>-79</sup> V/m.&nbsp; The result of the deformation analysis under the predefined extreme loading conditions shows a maximum deflection value of 197 mm at 10 m height and 0 mm at 0 m height of the tower. Additionally, the stress analysis result shows a predicted maximum value 3.28 x 10<sup>6</sup> N/m<sup>2</sup>&nbsp;&nbsp; between 0 m and 1.98 m height of the tower in the wind direction. The deformation was within the elastic limit of the tower material, because the total exerted extreme loads without the self-weight of the tower (2,397.54 N) was less than the determined safe load of the tower (7,107.96 N). The study has established that the selected horizontal axis wind turbine (HAWT) tower material was reliable under the predefined simultaneously applied extreme loads, thus the structural steel tower can function in areas this or similar loading conditions.</em></p> M. Shuwa A. B. Muhammad M. B. Maina Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 209 216 Production of Biocomposite from Parinari Polyandra Fruit Shell Using Waste Low Density Polyethylene as Matrix https://azojete.com.ng/index.php/azojete/article/view/589 <p><em>Enormous wastes that are continuously being generated from low-density polyethylene (LDPE) film sachet water have remained an environmental challenge in Nigeria. These might require urgent action due to the non-biodegradability of LDPE.&nbsp; Biocomposite samples were produced using waste LDPE sachets and Parinari polyandra shells, where filler sizes (0.420 mm, 0.841mm) and filler loading (10%, 20%) were varied. In this study, a melt mixer was designed and fabricated for the production of bio composite samples. Biocomposite samples were characterized using tensile tests, compression test, flexural and impact strength test, water absorption test, biodegradability, fourier transform infrared spectroscopy and scanning electron microscopy tests. Viscosity of the bio composite mix was a major constrain in the design of the melt mixer. The results revealed that the optimum value of tensile strength was obtained with particle size 0.42mm at a 10% filler to matrix loading which produced a Young’s modulus of 320.321 N/mm<sup>2</sup>. Higher particle size and filler loading elicited a higher value for compressive strength based on a force at peak value of 27552.500 N. Flexural, impact and tensile strength decreased with increasing filler loading and particle size, while increased immersion time gave increased percentage of water absorbed.</em></p> P. O. Odiase T. E. Odetoye Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 217 230 Load Frequency Control using Classical controllers https://azojete.com.ng/index.php/azojete/article/view/590 <p><em>This paper presents a solution to the problem of load frequency control of a two area power system using PI and PID controllers. In electric power systems, the load demand varies at different times of the day and these load variations lead to changes in frequency of the power system. In an interconnected power system, the tie-line power also varies in addition to the frequency variations. These changes in frequency and tie-line power causes instability in the power system network and make it unreliable. Load frequency control therefore ensures that these changes in the tie-line power and frequency of the control areas are minimized with acceptable level of overshoot and settling time. The method used involves the modeling of the two area interconnected power system using Matlab/Simulink software, the PI and PID controllers were then tuned using the Ziegler-Nichols tuning rule and used to simulate the two area power system when a load change of 0.2pu occurred in control area one. The simulation results showed that both the PI and PID controllers were able to restore the changes in tie line power and frequency of the control areas caused by the change in load to their steady state values of zero but the PID controller has better dynamic performances of overshoot, rise time and settling time than the PI controller.</em></p> U. I. Isemin A. J. Onah Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 231 242 Potential of Jesse Clay as Drilling Mud https://azojete.com.ng/index.php/azojete/article/view/593 <p><em>The high bottom hole pressure normally encountered during drilling, poses serious challenges during drilling operations of oil and gas wells. The unavoidable quest for crude oil source of energy by man, required for running its home and industries, makes the high risk pose by the underground hole pressure a risk-worth taking for new discovery of oil and gas reserve. The fear of encountered formation pressure is conquered by the use of drilling fluid (drilling mud). The drilling mud is a mixture of clay, water and chemicals. The drilling clay possesses certain properties that distinguished, and earmarked it as a drilling fluid, highest economy clay that is highly sorted/hunted for, either as purely for export for economic purpose by countries where it is found but have no oil or for oil and gas exploration activities in countries where hydrocarbon exploration takes pace. Nigeria as a country is a practical scenario of the above case the drill-mud–clay is being imported for the exploration of its large oil and gas reserve. Therefore, this paper seeks address the lingering unresolved challenges of the inability to establish Nigeria’s local drilling mud-clay with properties comparable with the existing imported drilling mud-clay through laboratory analysis of Nigeria clay. In searching for suitable Nigerian clay for to be used as drilling mud, two properties (mud density and sand content) of local clay extracted from Jesse, in Ethiope-West local government area of Delta State was analyzed and the results were recorded and compared with those of imported foreign clay. For their densities, the result was recorded as 8.41kg/m<sup>3</sup>, 8.50kg/m<sup>3</sup>, 8.50kg/m<sup>3</sup> and 8.67 kg/m<sup>3</sup> for local clay, and 8.60 kg/m<sup>3</sup>, 8.66 kg/m<sup>3</sup>, 8.67 kg/m<sup>3</sup> and 8.83 kg/m<sup>3</sup> for foreign /imported Bentonite. The percentage of sand content in both the local and imported foreign drilling mud after analysis, were recorded as 0.1%, 0.1%, 0.2%, 0.2% and1%, 1.5 %, 1.5 % and 2% respectively. The little differences noticed between the sand value of in the drilling mud prepared with local clay and imported clay, indicates that the local drilling mud can be at its best as drilling mud like the conventional drilling mud, which is in accordance with the API recommended value range of between 0.25% -1.2% if the experimented properties are further enhanced.</em></p> <p>&nbsp;</p> F. E. Otitigbe Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 243 254 Application of SEM/EDS in Fractographic Investigation of TIG Welded AISI 1020 Fusion Zones at Distinct Welding Current Steps https://azojete.com.ng/index.php/azojete/article/view/594 <p><em>Higher arc length is a function of increasing welding current (amperage). It increases the intensity of welding heat, thereby, influencing the microstructure and mechanical properties of the welded material. In this this study, fractographical variations in TIG welded AISI 1020 fusion zones at different welding current steps were investigated using Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) techniques. The fracture morphologies showed a fibrous appearance indicating ductile fracture with initiation of a river pattern of branching cracks, forming cleavages along the crystals plains and intergranular fracture occurring along the grain boundaries, indicating brittle fracture as a result of stepwise increase in welding current. It was observed that the ultimate tensile strength of the welded samples decreased correspondingly from 583.3 MPa, 540 MPa, 530.7 MPa, 506.7 MPa to 473.3 MPa as the resulting heat input due to welding current increased from 96.14 A, 120 A, 155 A, 190 A to 213 A. This indicated that the lowest welding current (96.14A) produced fusion zone with the highest ductility when compared to other welding currents which produced fusion zones that tended to be brittle as a result of increasing heat inputs. It was observed that fusion zone with the lowest welding current showed the appearance of a fibrous structure produced by stretching of crystals in their lattice during heat application. Micro-hardness on the surface of the welds revealed that hardness increased with increase in welding current. Therefore, proper control measures should be put in place to ensure that welding input parameters are optimum.</em></p> <p>&nbsp;</p> I. B. Owunna A. E. Ikpe J. U. Ohwoekevwo Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 255 266 Modelling the Performance Characteristics of Four Stroke Internal Combustion Renault Engine Cycle using Matlab Simulation Tool https://azojete.com.ng/index.php/azojete/article/view/595 <table> <tbody> <tr> <td> <p><em>The trends in Internal Combustion Engine (ICE) cycle is gradually changing due to the quest for optimum performance, efficiency and zero emission level which are often achieved through a series of experimental procedures. To reduce the huge experimental cost, time and resources, MATLAB 2018b was employed in the modelling and simulation process of a four stroke internal combustion Renault engine (Mercedes-Benz 250SE) W108 model. The displaced volume was 4.65x10<sup>-4</sup> mm<sup>3</sup> (4.65x10<sup>-7</sup> cm<sup>3</sup>) while the minimum volume occupied by the charge was 0.5x10<sup>-4</sup> mm<sup>3</sup> (5x10<sup>-8</sup>). Moreover, the maximum velocity occurred at a crank angle of 72º, having a value of 19.65 m/s while the minimum velocity occurred at a crank angle of 288º with a value of -19.65 m/s. However, maximum cylinder pressure of 28 bar was observed at crank angle of 20º, followed by gradual decline up to 0.2 bar at subsequent crank angles of 100, 200, 300º. The results showed that maximum peak pressure between simulated data and experimental data were 5347 and 5320 KPa, while maximum spark pressure in cylinder before combustion between simulated data and experimental data were 1849 and 1730 KPa. In addition, highest crank angle at maximum pressure for simulated and experimental data were 30 and 22º. It has been established that developing mathematical models to simulate IC engine operation cycles can help offset the cost, time and resources required for experimental set up, testing and data acquisition from the engine.</em></p> </td> </tr> </tbody> </table> <p>&nbsp;</p> A. E. Ikpe I. B. Owunna Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 267 280 Best-Fit Probability Distribution Model for Annual Monthly Maximum Rainfall in Calabar City, Nigeria https://azojete.com.ng/index.php/azojete/article/view/596 <p><em>The choice of a suitable model that could predict the possibility of occurrence of rainfall event of a specified magnitude depends mainly on the characteristics of rainfall data at a particular site. This study was aimed at determining the best-fit probability distribution model for annual maximum monthly rainfall. Fifty years rainfall data (1969-2018) obtained from Nigerian Meteorological Agency (NIMET), Calabar, were collated to form an annual series ranked in a decreasing order of magnitude. The data were then evaluated with 6 probability distributions namely; Normal, Log-Normal, Pearson Type III, Log-Pearson Type III, Gumbel Extreme Value Type I and Log-Gumbel probability distributions. The best-fit probability distribution model at the study area was selected based on the results of 4 goodness of fit tests namely; Mean Absolute Deviation Index (MADI), Chi-Squared</em> <em>) test, Root Mean Square Error (RMSE) and Relative Root Mean Square Error (RRMSE). The performance of the 6 distributions were ranked and the total scores of 8, 23, 16, 12, 21 and 4 were allocated to Normal, Log-Normal, Pearson Type III, Log-Pearson Type III, Gumbel Extreme Value Type I and Log-Gumbel probability distributions, respectively. The results indicate that the best-fit probability distribution model was Log-Normal, which was used to predict rainfall values of 566.8, 664.0, 721.6, 788.1, 834.4, 878.4, 920.7, 974.8 and 1014.4 mm for different return periods of 2, 5, 10, 25, 50, 100, 200, 500 and 1000 years, respectively. It is, therefore, recommended that Log-Normal distribution is the preferred model for frequency analysis of rainfall data for the planning and design of hydraulic structures in the study area. This is necessary for effective flood prevention and mitigation interventions</em><em>.</em></p> <p>&nbsp;</p> G. D. Akpen I. D. Ijasini G. N. Ekwo Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 281 294 Biolubricant Production from Parinari Polyandra and Azadirachta Indica Seed Oils using Trimethylolpropane Polyol. https://azojete.com.ng/index.php/azojete/article/view/597 <p><em>Environmental pollution over time has raised challenges that elicit concerns for the nearest future. Synthetic lubricants, especially those obtained from petroleum products, contribute to environmental pollution. Thus, there is a need for the production of environmentally friendly lubricant as an alternative to petroleum-based lubricant currently being used. This work explored the potential of Parinari and Neem oils for the production of biolubricant using double transesterification method. Parinari oil was extracted from parinari seed using Sohxlet extraction method, and neem oil was purchased from Akande market in Ogbomoso, Oyo state, Nigeria. Both oils were pre-analysed for physico-chemical properties based on American Society for Testing and Materials (ASTM) methods. Trimethylolpropane (TMP) was used to increase the lubricating property of the transesterified parinari seed oil. The results showed that, the kinematic viscosity for Parinari based lubricant produced ranged between 12.1 – 67.4 cP at 40 ℃ and 15.5-28.6 cP at 100 ℃, while the kinematic viscosity for Neem-based lubricant produced ranged between 55.7 – 647.3 cP at 40 ℃ and 122.9 – 171.6 cP at 100 ℃. Parinari based lubricant had a viscosity index ranging from 159.7-174.4 and neem-based lubricant ranged from 326-365. Viscosities were all compared against SAE standard. SAE 30, 40 and 50 had kinematic viscosities ranging between 9.3-12.5, 12.5-16.3 and 16.3-21.9 respectively. Furthermore, all the biolubricants showed relatively high viscosity indexes with potentials for application in heavy equipment. NBL showed higher kinematic viscosity with longer transesterification reaction time. NBL gave random outputs for each run for biolubricants produced. Therefore, Parinari and Neem oil-based lubricants are potential lubricants as an alternative to petroleum-based lubricant.</em></p> <p>&nbsp;</p> L. N. Bulus T. E. Odetoye Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 295 306 Kinetic Modeling of Ethylbenzene Isomerization using Bodenstein Approximation Technique https://azojete.com.ng/index.php/azojete/article/view/599 <p><em>Ethylbenzene isomerization reaction is a significant reaction employed in the production of xylene isomers which are used as petrochemical feedstocks. The reaction which proceeds over Pt/Al<sub>2</sub>O<sub>3 </sub>catalyst is multi-pathway and multi-cycle in topology. Kinetic model for the reaction was developed in this study using the general rate equation approach. Bodenstein approximation, cross-to-square, and Y-to-delta transformation techniques were used to reduce the complex reaction network to a single cycle network. In addition, the general rate equation for reduced single cycle networks was applied to derive the model for the reaction. The Nelder-Mead simplex optimization technique was used to estimate the kinetic parameters in the model. The structure of the model developed indicates that the model reasonably represents the mechanism of the reaction although few anomalies were observed in the values of the kinetic parameters estimated. The activation energy obtained for the rate constants follows the expected trend for multi-step reactions.</em></p> <p>&nbsp;</p> A. S. Kolo A. S. Grema I. I. Maina Copyright (c) 2022 Arid Zone Journal of Engineering, Technology and Environment published by University of Maiduguri, Nigeria https://creativecommons.org/licenses/by-nc-nd/4.0/ 2022-06-01 2022-06-01 18 2 307 318