Faculty of Engineering

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1-Minute Rain Rate Distribution for Communication Link Design Based on Ground and Satellite Measurements in West Africa
(Begell Journal, 2020) Dairo, Oluropo
West Africa is in the tropical region and it is characterized by intense rainfall. Rain is a significant factor causing signal degradation on microwave links due to its variability; it causes scattering, absorption, and refraction of electromagnetic waves. Experimental studies have shown that rainfall intensities above 64 mm/h at 0.01% in this region result in noticeable digital television signal fading, squelching and complete outages. Hence the need for estimating rain rate distribution across West Africa. This paper analyzed the rain rate in six countries in West Africa, namely Benin, Cameroon, Cote d'Ivoire, Ghana, Nigeria, and Togo. Three locations were selected in each country. Rain data were obtained from the Tropical Rain Measuring Mission-Precipitation Radar (TRMM-PR) and the Global Precipitation Measurement (GPM) missions, and Tropospheric Data Acquisition Network (TRODAN) weather stations in Nigeria. This study used ITU-R and Moupfouma models for the conversion of the 5-minute rain rate to 1-minute integration time at a probability of exceedance ranging from 1% to 0.001%. The cumulative rain rate distribution from the measured rain rate is presented alongside the predictions of the models. ITU-R and Moupfouma predicted similar results at 0.1% probability of exceedance. ITU-R overestimates the rain rate above 0.01% probability of exceedance. On the other hand, the Moupfouma models prediction plots at 0.01% overlap for all locations, indicating that there will be a signal loss at 0.01% probability of exceedance across these locations. The result shows that the 5- minute conversion provides satisfactory performance and is suitable for estimating the 1-minute rain rate statistics required for propagation planning over West Africa.
a-Amylase inhibition, anti-glycation property and characterization of the binding interaction of citric acid with a-amylase using multiple spectroscopic, kinetics and molecular docking approaches
(Elsevier, 2022-05) Dairo, Oluropo
The quest to suppress complications associated with diabetes mellitus is ever increasing, while food addi- tives and preservatives are currently being considered to play additional roles besides their uses in food enhancement and preservation. In the present study, the protective prowess of a common food preserva- tive (citric acid, CA) against advanced glycation end-products (AGEs) formation and its binding interac- tion mechanism with a-amylase (AMY), an enzyme linked with hyperglycemia management, were examined. Enzyme inhibition kinetics, intrinsic fluorescence, synchronous and 3D fluorescence spectro- scopies, ultraviolet–visible (UV–Vis) absorption spectroscopy, Fourier transform-infrared (FT-IR) spec- troscopy, thermodynamics, and molecular docking analyses were employed. Results obtained showed that citric acid decreased a-amylase activity via mixed inhibition (IC50 = 5.01 ± 0.87 mM, Kic = 2.42 mM, Kiu = 160.34 mM) and suppressed AGEs formation (IC50 = 0.795 ± 0.001 mM). The intrinsic fluorescence of free a-amylase was quenched via static mechanism with high bimolecular quenching constant (Kq) and binding constant (Ka) values. Analysis of thermodynamic properties revealed that AMY-CA complex was spontaneously formed (DG < 0), entropy driven (TDS > DH), with involvement of electrostatic forces. UV–Vis, FT-IR and 3D fluorescence spectroscopies affirmed alterations in a- amylase native conformation due to CA binding interaction. CA interacted with His-101, Asp-197, His- 299, and Glu-233 within AMY active site. Our findings indicated that CA could impair formation of AGEs and interact with a-amylase to slow down starch hydrolysis; vital properties in management of type 2 diabetes complications.
Adaptive Network Based Fuzzy Inference System Model for Minimizing Handover Failure in Mobile Networks
(International Journal of Innovative Science and Research Technology, 2017-09) Orimogunje, Abidemi
For seamless connection between mobile users on the same and different mobile technologies there is need for the deployment of a more complex algorithm for a successful switching of mobile users. Signal to interference ratio, speed of the mobile users and traffic distance are the three input used in the Adaptive network based Fuzzy inference system (ANFIS) which is an hybrid of two techniques of artificial intelligence which make it suitable to handle complexities such as ping-pong effect and interference which impair on the quality of service (QoS) during call handover process as the mobile users move from one coverage area (cell) to another.
Advanced Digital Laboratory: an FPGA-Based Remote Laboratory for Teaching Digital Electronics
(American Society for Engineering Education, 2009, 2009-06) Osasona, Oladipo
The experimentation component of most Science and Engineering curricula in Nigeria is inadequate. In Obafemi Awolowo University for example, undergraduate students typically carry out around five assignments related to digital electronics, and there is no treatment whatsoever of Field Programmable Gate Arrays(FPGAs). In the research work being reported, an attempt has been made to develop a remote laboratory though which the number of digital electronics experiments students carry out can be increased. The remote laboratory, called the Advanced Digital Lab (ADLab), allows students to synthesis digital systems on an FPGA with a hardware description language. To achieve this, a development board with an Altera Cyclone II FPGA is connected to a computer implementing the server tier of the iLab batched architecture. The client through which the remote student interacts with the ADLab is implemented with Java, which allows for a reasonable amount of platform independence. This paper discusses the software and hardware aspects of the ADLab architecture and gives some insight into some design decisions. The paper also reports that the system is being tested at Obafemi Awolowo University and that student feedback so far indicates high student satisfaction with the remote laboratory.
ARDUINO-BASED MAXIMUM POWER POINT TRACKING CHARGE CONTROLLER USING PERTURB & OBSERVE AND CONSTANT-VOLTAGE ALGORITHMS
(Begell House, Inc. www.begellhouse.com, 2023) Ilori, A. O.; Dairo, O. F.; Willoughby, A. A.; Osinowo, M. O.; Ewetumo, T.
The output power delivered by a photovoltaic (PV) module to charge a battery is dependent on solar radiation incident upon it and the ambient temperature. To reduce PV energy loss, the PV panel is kept at peak efficiency by operating the PV system at the maximum power point (MPP) to deliver maximum power to the battery under charge. In this work, Perturb & Observe (P&O) algorithm was implemented in conjunction with constant voltage (CV), using the MATLAB/Simulink tool. Results obtained from these simulations show that the tracking efficiency of the P&O algorithm decreases with solar irradiation. However, the relatively good performance of the CV algorithm at low irradiation levels augments the P&O method. Both algorithms were implemented in a maximum power point tracking (MPPT) design using an ATMega328 microcontroller operating on a minimal Arduino-compatible integrated development environment (IDE) prototype circuit.
Assessment of Five Predictive Models for Solar Radiation in Southwest Nigeria
(LivingScience Foundation, 2020-10) Dairo, Oluropo
This study compares the accuracies of five predictive models for estimating solar radiation amongst other meteorological parameters in Southwest Nigeria. Twenty-one years of monthly averages of six measured meteorological parameters obtained from six stations in southwest Nigeria have been subjected to five mathematical models for prediction purposes. Solar radiation and sunshine hours have been modelled using the sum of two-Gaussians, the sum of two-Lorentzians, Fourier on four harmonics, sine wave and fourth-order polynomial functions. The fitting accuracies of these models were tested using performance indicators; mean bias error (MBE), root mean square error (RMSE), mean percentage error (MPE), standard error (SE) and the correlation coefficient (R). An evaluation of the models showed that the Gaussian and Lorentzian models are in good agreement with the observed data. However, the Fourier on the fourth harmonics model had the lowest MBE, RMSE and MPE, consequently highest correlation coefficient values, indicating high model accuracy. Thus, the Fourier model has the best correlation with the observed data and is recommended for estimating these variables in the selected locations.
Assessment of Musculoskeletal Discomfort Among Mini-Bus Drivers In Osun State, Nigeria.
(International Journal of Progressive Sciences and Technologies (IJPSAT), 2022) Sanyaolu, Olufemi
There have been many reports on the physical factors contributed to the development of work-related musculoskeletal disorders (WMSD) which have a negative influence on the health of employee across different occupations including bus drivers. This study focuses on the assessment of musculoskeletal disorders among mini-bus drivers popularly called “Korope” in the Osun State of Nigeria. This research is based on questionnaires extracted from the standard Nordic questionnaire for the assessment of musculoskeletal disorders (MSDs). The results obtained from the questionnaire showed that the low back, knee and the ankle/feet were found to be the most common areas of discomfort among the population. The elbow showed the least area of musculoskeletal discomfort while the shoulder,upper back, neck, thigh/hips and the wrist/ hands showed moderate discomfort. Some of the subjects experienced at least two of the discomforts
Cathode Materials for Lithium-ion Batteries: A brief review
(International Information and Engineering Technology Association (IIETA), 2021) Dairo, Oluropo
Layered lithium cobalt oxide (LiCoO2) as a pioneer commercial cathode for lithium-ion batteries (LIBs) is unsuitable for the next generation of LIBs, which require high energy density, good rate performance, improved safety, low cost, and environmental friendliness. LiCoO2 suffers from structural instability at a high level of delithiation and performance degradation when overcharged. Besides, cobalt, a significant constituent of LiCoO2 is more costly and less environmentally friendly than other transition metals. Therefore, alternative cathode materials are being explored to replace LiCoO2 as cathode materials for high-performance LIBs. These new cathode materials, including lithiated transition metal oxides, vanadium pentoxides, and polyanion-type materials, are reviewed in this study. The various challenges hampering the full integration of these cathode materials in commercial LIBs and viable solutions are emphasised.
Characteristics of rain fade slopes on microwave communication in Mowe, Nigeria
(IOP Publishing, 2021) Dairo, Oluropo
In this paper, the rain fade characteristics at Ka-band (30 GHz) in Mowe (Lat 6.80o N, Lon 3.40o E) Nigeria have been presented. The analysis includes both the first- and second- order statistics of rain rate and rain attenuation, and fade duration and fade slope, respectively. Both parameters are useful for planning the point-to-point microwave link for various communication feeder networks. The estimated fade duration and the fade slope were compared with the ITU-R P.837-5 model. The results of this study would be valuable for improving rain fade mitigation techniques in Nigeria.
Corrosion Protection by Novel Conversion Coatings on Structural Al 6061
(Applied Science and Engineering Progress, 2022-02-03) Adesina, Olanrewaju
Chromate conversion coatings have witnessed limited acceptability in recent times. The coatings contain Cr (VI) species that have been classified as environmental hazards and injurious to human health. Thus, the use of environment-friendly and non-carcinogenic novel inorganic-inorganic hybrid conversion coatings are being explored. Vanadate (VCC), hybrid Vanadate/Molybdate (HCC) conversion coatings on Al6061 have been classified in terms of corrosion and adhesion performance with reference to the untreated alloy. Natural exposure tests in the atmosphere and stagnant near-neutral 3.5% sodium chloride solution, as well as potentio-dynamic polarization measurements showed that the corrosion rate for HCC is lower for Vanadate, which in turn outclassed the ‘bare’ alloy. However, clusters of passive incipient pits were revealed on the former after 120 h of exposure in stagnant chloride solution. Both conversion coatings outperformed the untreated aluminium alloy after atmospheric corrosion and adhesion tests.
Co‑pyrolysis of Cassava Peel with Synthetic Polymers: Thermal and Kinetic Behaviors
(Elsevier: Waste Disposal & Sustainable Energy, 2021-10) Adedoja, Adedotun
This research efort focuses on the co-pyrolysis of cassava peels waste and some synthetic polymers towards energy conversion and reducing the volume of these waste fractions dumped on dumpsites. The co-pyrolysis behavior and pyrolysis kinetics of various synthetic polymer wastes/cassava peel blends were investigated by blending cassava peel waste with low-density polyethylene (LDPE), polyethylene terephthalate (PET), and polystyrene (PS) at diferent weight ratios. The physical characteristics of each sample were investigated and the co-pyrolysis experiments were conducted at a heating rate of 10 °C/min from room temperature to 800 °C in N2 atmosphere in a thermogravimetric analyzer. Subsequent to thermal decomposition, kinetic analysis was done using the thermogravimetric data. Results from physicochemical characterization showed that cassava peel has a relatively lower calorifc value of 15.92 MJ/kg compared with polystyrene (41.1 MJ/kg), low-density polyethylene (42.6 MJ/kg), and polyethylene terephthalate (21.1 MJ/kg). The thermal decomposition behavior of cassava peel was seen to be signifcantly diferent from those of the synthetic polymers. The decomposition of the biomass material such as cassava peel generally occurs in two stages while the decomposition of LDPE, PS, and PET occurred in a single stage. The activation energy required for thermal degradation in cassava peel was also found to be lower to that of the plastic material. The co-pyrolysis of cassava peel and diferent synthetic polymers afected the thermal and kinetic behaviors of the blends, reduce the activation energy and residue after pyrolysis.
Design of Aluminum Eco-composite for Sustainable Engineering Application by the Valorization of Municipal Wastes:
(Elsevier, 2024-01-14) Adesina, Olanrewaju
Reprocessing municipal wastes into useful engineering components is one way to reduce their environmental impact. This paper presents a report on an alternative experimental approach to reprocessing common envi ronmental wastes like aluminum scraps, steel shavings, and coconut shells into eco-friendly engineering com posite. Equally, response surface analysis was incorporated in the development and validation of predictive models fit for future prediction of response properties. Aluminum scrap was heated into a liquid state and reinforced with recycled steel particles (RSP) and coconut shell ash particles (CSP) at varying proportions. Specimen design involves three group mixes: A, B, and C. Each of the three groups mixes comprised 0, 1, and 2 % RSP at constant dosage, respectively. Meanwhile, each mix was incorporated with 4, 8, and 12 wt % CSP. The microstructural features, physical (porosity, density, and relative density), and mechanical (tensile strength, hardness, elastic modulus, fracture toughness, impact strength, and percentage ductility) properties were appraised. The outcome revealed that the combination of the two reinforcements (RSP and CSP) contributed to microstructural evolution within the specimens. The porosities of the composite specimens were reported to marginally increase with the reinforcement combination. Interestingly, the composite exhibited lighter weight with improved mechanical performance. Mathematical models derived for the response properties were certified fit for future analysis and predictions. Meanwhile, the optimization procedure revealed that the combination of 1.3 % RSP and 6.7 % CSP was suitable for the design of optimal recycled aluminum composites for sustainable engineering designs. The results clarified that the reinforcement particles (RSP and CSP) are low-cost alternatives to synthetic ceramic reinforcements in the aluminum composite."
Development of a face recognition system using hybrid Genetic-principal component analysis
(1st International Conference on Electrical, Electronic, Computer Engineering & Allied Multidisciplinary Field, 2021-12) Ibikunle, Akinola
Humans have been using physical attributes such as face, voice gait and fingerprints to recognize each other for ages. With the recent technological advancement, face recognition is a branch of biometrics system which has received considerable interest because of its ease in collecting, analysing and recognising face images. It is a system which compares an unknown image against the trained images in a database in order to identify the image. It has a number of applications such as Automatic Teller Machine (ATM), credit card, physical access control, National Identity card and correctional facilities. It has been found to be one of the ways of controlling and reducing crime rate. The development and evaluation of the performance of a face recognition system using hybrid Genetic- principal component Analysis technique is presented. The system consists of three major subsystems. Initial preprocessing procedures are applied on the input face images selected from the ORL Database. Consequently, face features are extracted from the processed images by principal component analysis and finally face identification is carried out using Genetic algorithm. Image resolutions of 50 x 50, 70 x 70, 100 x 100 and 140 x 140 are used in training and testing the system. The identification rates obtained were 100%, 96.36%, 93.63% and 90.90% for 50 x 50, 70 x 70, 100 x 100 and 140 x 140 respectively. This experimental result revealed that the lower the resolution of the cropped images, the higher the number of the correctly identified face images. The reason is attributed to the fact that there is variation in the features considered for recognition for each resolution. Hence, this technique has been proved to be more robust and suitable for low resolution.
Development of a High Efficient Manual Furnace Blower of the Local Charcoal-Fired Furnace for Aluminium Recycling
(Iconic Research and Engineering Journals, 2022-05) Sanyaolu, Olufemi
The charcoal-fired furnace is usually used for Aluminium recycling for the production of cooking utensils in local small-scale Aluminium recycling industries. The performance of such a furnace and manual operated blower was carried out to determine the efficiency and energy consumption in the cause of electrical power failure. Towards this objective, measurements were taken of the quantity of charcoal used for different melts and their corresponding melting times and temperatures. The wheel gear speed ratio of 1:16 was calculated, the energy used was determined and the efficiency calculated. The efficiency obtained for the furnace and the manual-operated blower was 11.6%. The value was obtained as a result of variable atmospheric conditions, non-uniform speed, and the open nature of the environment and the furnace.
Development of an Operational Amplifier Virtual Laboratory based on iLab Architecture and NI ELVIS
(American Society for Engineering Education, 2008) Osasona, Oladipo
We have developed and deployed ‘OpAmp Lab’, a pedagogic operational amplifier virtual laboratory based on the MIT iLab architecture. The architecture is a three-tier architecture that abstracts the various parts of a remote laboratory system into different functional domains. This architecture makes the new virtual Lab experiments scalable and reduces the development and deployment time of new experiments through component reuse. OpAmp Lab uses the National Instrument ELVIS hardware platform for experimental set-up. Basic Op-amp circuits are realized through reconfigurable Dozen Impedance Op-amp configuration mounted on a multimode switch array. The front end or Client is implemented as a Winform Client, written in C# and uses connectible nodes as a metaphor for back-end hardware configuration. Strong emphasis is placed on the realism of the user interface, as we argue, the user interface is the most important determinant of the quality of a user’s educational experience. We discuss the various components of OpAmp Lab and the lessons learnt in the development of the system as well as the development of pedagogical experiments developed for it. OpAmp Lab has been in use at Obafemi Awolowo University, NIGERIA for the last two years. Faculty and students response has been strongly positive. We provide data showing that the Lab offers a viable means of augmenting the laboratory component of electrical engineering curricula in developing countries.
Development of Sacrificial Anode from Al, Mg, and Ti from Iron Ore Tailings
(Taylor & Francis Group, 2024-03-07) Adesina, Olanrewaju
This investigation used aluminium, magnesium, iron ore tailings, and low-carbon steel. Iron ore tailings (5–30 wt% Mg and 50 μm in size) in an aluminium matrix formed the anode. In 0.5 M NaCl solution, the weight loss, corrosion rate, and electrochemical properties were measured. Samples A to E have corrosion rates of 0.43, 0.28, 0.36, 0.08, and 0.11 mm/yr, respectively. SEM/ EDS examination revealed the presence of elemental Al, Mg, O, and Si in the anode. The XRD patterns indicate intermetallic compounds such as iron nitride (Fe3N), aluminium silver (Ag-Al), and manganese zirconium (Mn2Zr). In samples A, B, and C, Al and Mg formed a protective coating on the anode, while C and Si reduced passivation and released electrons to protect the steel. IOTs and Mg in the aluminium matrix improve the anodic corrosion resistance. The observed improvements in corrosion resistance highlight the potential of these sacrificial anodes for practical applications in corrosion protection systems
Development of Ultra Low-Cost Data Acquisition System (DAS) for Developing Countries
(Walailak University, 2022-07-01) Dairo, Oluropo
The Data Acquisition System (DAS) is an important equipment in measurement systems, especially in weather monitoring and also very crucial in many areas such as agricultural, communication, transportation, sport and industrial processes. This work proposes a weather monitoring system based on an Arduino Mega 2560 microcontroller board. The microcontroller has the ability to monitor, record and display the information of atmospheric sensor parameters connected to its analogue and digital pins. The outputs of analogue sensors are connected to the microcontroller through separate ADC for sampling. An LCD attached to the microcontroller displays the measured parameters. For analysis, the data is stored in excel format and can be copied directly from a microSD card. The DAS was tested and examined through intensive experimental work. From the tables and plots obtained from the experiment for standardizing the sensors, it is clear that there is close conformity between the data collected by the developed system and the existing standard systems. The need for extra cost baud rate and expensive third-party computer software for interfacing to download data from the logger has been eliminated. There is no need for the internet for any linking or configuration. It is evident that the DAS is of better choice in terms of cost and maintenance. The system will be helpful in monitoring and recording atmospheric parameters.
Developmentof a Propagation Model for IEEE 802.11 Wireless Networks: Case of GidanKwano Campus, FUT MINNA
(Ahmadu Bello University Zaria Proceedings of the 1st National Communication Engineering Conference 2018, 2018-10-18) Ogunjide, Sunday
Wireless propagation modeling is an essential task in planning wireless networks. In the last few decades, the use of Wireless Local Area Network (WLAN) popularly referred to as Wi-Fi(Wireless Fidelity) in communication system has been on the increase with the exponential usage of handheld cell phones, laptops, and palm-tops to mention but a few. Notwithstanding, WLAN faces a peculiar propagation issue which lies in its changing propagation environment and this affects the quality of service. Poor quality of service is experienced on WLAN of GidanKwano campus of Federal university of technology, Minna. This arises due to signal propagation impairment caused by the terrain and the structures within the campus. Received Signal Strength (RSS) measurements were conducted at different locations away from the selected Access Points (APs) both in Line of Sight (LOS) and Non- Line of Sight (NLOS) situations. The path loss exponent (n) and standard deviation (σ) were estimated for the environment. The obtained results were contrasted with the already published work to show the level of agreement. The empirical models were developed for LOS and NLOS situations and compared with the existing standard models.
Effect of SiC addition on Laser‑based CoNi Binary Alloy Coatings on Ti‑6Al‑4V alloy
(Springer, 2024-04-25) Adesina, Olanrewaju
This research explores the impact of variations in laser scanning speed and the incorporation levels of SiC-Ni-Co powders on Ti-6Al-4V alloy using laser surface cladding technique. Key parameters, including a consistent laser power of 700 W, a 4 mm beam spot size, a powder feed rate of 1.0 g/min, and a gas fow rate of 3 L/min, along with fxed powder composi tions, were maintained. The laser scanning speeds were adjusted to 0.4 m/min, 0.8 m/min, and 1.2 m/min. Microstructural analyses were carried out using scanning electron microscopy (SEM) while Vickers microhardness was employed to assess coating hardness, and corrosion properties were evaluated using a linear potentiodynamic polarization technique. Follow ing the corrosion attack, the protective oxides formed were identifed through SEM and X-ray difractometer (XRD). The results revealed a strong metallurgical relationship between the clad layer and the substrate, demonstrating the efectiveness of the laser-clad technique. Particularly, the highest laser scan speed exhibited the most signifcant improvements in hardness and corrosion resistance. The coatings displayed an average hardness value of 1269.20 HV0.1, a notable fourfold increase compared to the substrate's value of 334 HV0.1. Concerning corrosion, a clear correlation emerged between scan speed and polarization resistance, confrming that higher scan speeds could lead to enhanced polarization resistance
Effect of Varying Cathode–Anode Parameters on Performance of Mild Steel Cathodically protected by the Aluminum Anode in 0.5 m NaCl Environment
(Springer, 2024-01-19) Adesina, Olanrewaju
This work investigates the efect of varying cathode–anode parameters on the performance of mild steel cathodically pro tected by the aluminum anode in 0.5 M NaCl environment. The study aimed to assess the corrosion protection efcacy of the cathodic protection system and identify optimal parameters for maximizing protection while minimizing energy con sumption. Impressed current system was employed to drive the aluminum electrons from the anode to the cathode to achieve cathodic protection of the mild steel cathode. Using Optical Electron Microscope, Scanning Electron Microscope with an electron difraction spectrometer, and X-ray difraction, the cathodically treated mild steel samples were characterized. The rate of mild steel corrosion was determined by adopting the potentiodynamic polarization method together with the weight loss method in a 0.5 M NaCl environment. Certain parameters including the working voltage, exposure time and electrode separation distance were also used to analyze the optimal features of the cathodic protection during the experiment. The fndings demonstrated that, across the distances and exposure times, an aluminum anode operating at working voltages of 3 and 4 V in a 0.5 M NaCl environment provided sacrifcial protection for the mild steel (cathode). The working voltage of 4 V yielded the best cathodic protection in 0.5 M NaCl at 5 cm for 15 min. Furthermore, at a working voltage of 5 V, efcient protection of the mild steel was achieved only at electrodes separation distances above 15 cm, while overprotection of the cathode which could possibly cause cathodic disbondment was observed at electrodes separation distances of 5 cm, 10 cm and 15 cm. The results of this experiment have practical implications for the development and improvement of cathodic protection systems for mild steel structures in environments with high levels of chloride. This highlights the signifcance of considering cathode–anode parameters to efectively reduce corrosion and ensure the long-term structural stability in the maritime industry and sub-sea operations

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