LAUTECH Journal of Engineering and Technology <p>LAUTECH Journal of Engineering and Technology (LAUJET) is a leading internationally referred journal in the fields of science, engineering and technology. It is a journal founded by academicians, educationists with substantive experience in industry. The journal is an online open access journal with a yearly print version of its volumes/issues made available to interested persons/institutions. The basic aim of the journal is to promote innovative ideas in fields relating to the sciences, engineering and technology. The basic notion of having a wide area of focus is to encourage multidisciplinary research efforts and seamless integration of diverse ideas that might be gleaned from the papers published in the journal.</p> <p>&nbsp;</p> en-US (Engr. Prof. JEKAYINFA Simeon Olatayo) Tue, 28 Jun 2022 00:00:00 +0000 OJS 60 SENSITIVITY ANALYSIS OF HYBRIDIZED WIND/PV ENERGY SYSTEM FOR POWERING TELECOMMUNICATION MAST IN LAGOS SOUTH-WEST NIGERIA <p><strong><em>Power delivery micro-grid of hybridized wind and solar system installations keep growing worldwide. There is a great economic advantage in the use of cleaner renewable energy for power generation in the telecommunication industries, especially in remote areas. This studyanalyses the effect of three wind speed fluctuationsor levels on a hybridizedwind energy system’s electricity production for a typical three (3) BTS telecommunication mast using </em></strong><strong><em>Hybrid Optimization Model for Energy Resources</em></strong><strong><em> (HOMER)PRO software in Lagos south-western Nigeria as a case study. The economic implication of energy at the different wind speed levels investigated was also derived. From the obtained results, a wind speed of 4, 4.22, and 5 m/s gave an annual electric production of 39,950, 39,050, and 39,250 kWh and energy cost of 195, 192, and ₦175, respectively. This result is useful for the techno-economic operation of hybridized wind/solar system powered by three (3) BTS telecommunication masts.</em></strong></p> O. Olaogun, A. A. Lawal, A. J. Adeyi, O. Adeyi, A. D. Ogunsola, M. O. Ibiwoye, A. A. Adegbola ##submission.copyrightStatement## Tue, 28 Jun 2022 00:00:00 +0000 AN EXPERIMENTAL INQUIRY INTO SURFACE ROUGHNESS OF PAINT-FINISHED MILD STEEL BY SOME TOP AUTOBODY SPRAY PAINTERS IN KADUNA METROPOLITAN AREA, NIGERIA <p>Body finish appeal is one of the first noticeable things about any automobile. Most factory autobody painting is highly automated, so aesthetically appealing body finishes of high quality are efficiently achievable with high production rates. However, autobody painting for maintenance or repair in Nigeria is mostly done using manual skills and minimally automated facilities, with a high chance of ending up with low-quality or unappealing body finishes. The purpose of this paper is to present an experimental comparative study about the average surface roughness of paint-finished auto bodies by three top artisanal autobody spray painters, named MA Motors, Alsarafa Body Painters, and IBK Motors in Kaduna metropolis, Nigeria, relative to factory-painted vehicles at Peugeot Automobile Nigeria (PAN) Plc and relevant engineering standards. A cold-rolled mild steel sheet was procured for the study as the most common but corrosion-susceptible autobody material. The sheet was ascertained through nominal composition analysis and was used to produce four similar-sized sheet samples. The samples were individually taken to each of the spray painters and PAN, where they were surface-cleaned, painted, and cured according to the usual methods and standards used there in paint-finishing auto bodies. The surface roughness of the paint-finished samples was measured at 20 different points on each sample with the CRV-135 surface roughness tester and analyzed statistically in terms of the mean value (Ra), root mean square, depth to peak ranges, skewness, kurtosis, and variance. The obtained results indicated that the paint finishes from IBK Motors, Alsarafa Body Painters, MA Motors, and PAN had Ra values of 1.368µm, 1.4725µm, 1.6495µm, and 1.258µm, respectively. The analysis also indicated that all the paint-finished surfaces had minimal roughness, uncharacterized by excessive variations, peaks, and valleys, about their flat average values. The analysis finally indicated that autobody paint finishes by the spray painters are of similar and high quality by engineering standards and comparable to finishes at PAN. The paper provides useful insight into the surface roughness of paint-finished auto bodies by the spray painters as a fundamental quality control parameter that should be imbibed by all in the auto-body painting business, especially in Nigeria, to meet requirements by standards, customers, and users.</p> T. N. Guma, Josiah Gana ##submission.copyrightStatement## Tue, 28 Jun 2022 00:00:00 +0000 THE STRENGTH CHARACTERISTICS OF GLULAM AND BOLT- LAMINATED BEAM <p>This research presents the strength characteristics of Glulam and Bolted Beam timber specimens. The most common connection method in timber construction is the nail. It is imperative to explore other methods such as glue and bolt in order to avert the disadvantages of nails such as labour intensive and increase in cost. Experimental investigation was carried out on three selected Nigeria timbers; Ceiba Pentandra, Terminalia ivorensis and Tectona grandis. The specimen was prepared in sizes as either glued, bolted or solid connection. Moisture content, density, compression parallel and perpendicular to grain and flexural tests were carried out in the laboratory. The glulam beam specimen; Ceiba Pentandra, Terminalia ivorensis and Tectona grandis showed some positive potentials for application than the bolt-laminated beam connection. It was concluded that bolted connection can be improved by increasing bolt sizes and connection points.</p> John Wasiu, Okore Kalu Nnamdi Eric, Akintade Olufemi Ezra ##submission.copyrightStatement## Tue, 28 Jun 2022 00:00:00 +0000 MODELLING AND OPTIMIZATION OF COEFFICIENT OF PERFORMANCE OF LOWER TEMPERATURE CYCLE OF TWO-STEP REFRIGERATION SYSTEMS <p>The coefficient of performance (COP) of a single-stage refrigeration system is low, thus there is a need for two-step refrigeration systems when there is a desire to have an evaporator temperature that is below -25 oC. The COP of the lower temperature cycle of the two-step refrigeration systems is a function of the COP of the refrigeration systems.This research aimed at optimizing COP of the lower temperature cycle of two-step refrigeration systems using eco-friendly refrigerants.Thermodynamic analysis of these refrigeration systems was performed by varying seven operating parameters. R-134a was used in the high-temperature cycle (HTC) and R-23 was used in the low-temperature cycle (LTC). The coefficient of performance of the lower temperature cycle (COP.REF[LTC]) of the refrigeration systems was optimized using Half Factorial Design of Design-Expert 12.0.1. The influence of the condensing temperature (TC,HTC),evaporating temperature (TE,HTC), cascade temperature difference (∆TCAS,DIFF), evaporating temperature (TE,LTC), superheating temperature (TSUP,LTC), sub-cooling temperature (TSUB,LTC), and refrigerant mass Flow rate (ṁHTC)was investigated on the values of COP.REF[LTC] of the refrigeration systems. The highest value of COP.REF[LTC] (18.1) was obtained under optimum conditions of the 30 TC,HTCoC , -40 TE,HTCoC, 0 ∆TCAS,DIFFoC, -50 TE,LTCoC, 0 TSUP,LTCoC, 20 TSUB,LTCoC and 0.01 ṁHTC kg/s.The study revealed that all the factors having interaction with TC[HTC] and TE[HTC] have a great influence on the value of COP.REF[LTC]</p> A. D. Ogunsola, M. Y. Kolawole, A. A. Aderibigbe, O. Olaogun, A. J. Adeyi, O. Adeyi, M. O. Ibiwoye, M. O. Adetunji ##submission.copyrightStatement## Tue, 28 Jun 2022 00:00:00 +0000 FILE ENCRYPTION AND HASH SYSTEM USING JAVA PROGRAMMING LANGUAGE FOR IMAGE STEGANOGRAPHY <p>Due to the rapid development and rapid popularization of the information technology, internet and digital media have become an important tool for military, commercial, individuals and many other organizations to obtain and transmit information. However, digital communication via the Internet is vulnerable to eavesdropping, malicious interference and other activities. As a result, data transmission protection and information security issues become a bottleneck than ever before. This paper presents file encryption and Hash system (Image Steganography) via Least Significant Bit (LSB) approachto increase the amount of text file the cover image can conceal. The software used consists of two sections: the Encode section (embedded text file by using an image as cover) and the Decode section (extract the embedded text from the cover image) which is implemented through NetBeans IDE using Java Programming Language.The different results obtained when the proposed device was tested revealed that it worked according to the design specifications.</p> O. K. Adejumobi, M. O. Ayeni, A. H. Adeyeye, O. A. Ogundeji ##submission.copyrightStatement## Tue, 28 Jun 2022 00:00:00 +0000 DIFFERENTIAL MATURITY ACROSS LATERITIC PROFILES FROM ILORIN, NORTH CENTRAL NIGERIA <p>This study characterizes the three distinct horizons of the lateritic profiles within the study location with the view to determining their relative degrees of laterization. The three distinct horizons (the upper crustal, middle gravelly and basal less/non gravelly) were subjected to series of geotechnical tests to determine parameters such as Grain size distribution, Atterberg limits, Specific gravity, California bearing ratio, Compaction and Shear strength. The results of the tests elucidated a useful connection between the parameters determined and the degree of laterization. The middle horizon, which is the gravelly horizon, has the highest specific gravity out of the three horizons and a lower clay content than the basal less/non gravelly horizon, both of which are indicative of a higher degree of laterization.It also shows relatively improved and enhanced values for the other parameters such as California bearing ratio, Shear strength and Atterberg limits, which further indicates that the gravelly horizon has attained a higher degree of maturity compared to the others. It is thus expected to have the best engineering performance</p> O. A. Odediran ##submission.copyrightStatement## Tue, 28 Jun 2022 00:00:00 +0000 MODIFICATION OF BLADE CHORD INFLUENCE ON THE PERFORMANCE AERODYNAMICS OF VERTICAL AXIS WIND TURBINES <p>Performance aerodynamics of VAWTs is given important considerations whenchoosing design parameters for the manufacturing of VAWT to effectively and efficiently perform after installation. Blade chord is amongst the many design parameters that can affect the CP of VAWTs in relation to wind harvest and energy yield. This study examines the influenceblade chord modification can have on the PA of wind turbines. The VAWT blade chord of NACA0022 was modified and two configurations of rotors, one with C = 0.03m and the other of C = 0.04m were tested in a low speed and low turbulent intensitytunnel at several wind speeds. An appropriate performance measuring techniques was used to conduct the tests on the two VAWT configurations. The results showed substantial differences in the measured performance efficiency of the two configurations. The two rotorsreached peak performances at the highest tested freestream speed of 8 m/s. The VAWT configuration of C = 0.04m attained higher performance with peak CP = 0.326 at λ = 3.75 while the C = 0.03m showed lower peak CP = 0.26. Changes in the CPwere seen in relation to changes in the free wind speeds.Also the peakperformanceschanged positively as the wind speed is increased. The curves of plot of the CP - λ is observed to close up at region of the peak performances. The CP, the performance efficiency and aerodynamics of the two rotors and configurations are shown tohave been visibly affected bythe modification of the blade chord.</p> Okeoghene Eboibi ##submission.copyrightStatement## Tue, 28 Jun 2022 00:00:00 +0000 Efficacy and Effect of Selected Bio-Cogulant on Treatment of Aponmu River <p><strong><em>&nbsp;</em></strong><strong><em>In the wastewater treatment process of coagulation-flocculation-sedimentation, natural coagulants may be used to reduce turbidity. Manihot Esculenta (cassava peel) and Citrus Aurantium Dulcis (orange peel) were employed as natural coagulants for the treatment of Aponmu river. The best overall results were obtained when alum was partially replaced with cassava peel (70% AL30% CA), with all parameters (BOD; 6.1mg/L, COD; 9.9mg/L, hardness; 85.6mg/L, and Cu; 0.07mg/L, at pH of 6.3) meeting WHO drinking water standards and accepted practices for water and wastewater examination. However, alum's negative environmental effects on the production of non-biodegradable sludge and lingering effects on treated water are greatly reduced by partial substitution.</em></strong></p> E. O. Fakorede, O. K. Akinmusere, A. D. Babajide, T. T. Bamgboye ##submission.copyrightStatement## Tue, 28 Jun 2022 00:00:00 +0000