LAUTECH Journal of Engineering and Technology (LAUJET)
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Three phase microcontroller based automatic change-over selection switch
Get PDFThe significance of electricity in a developed country cannot be underestimated because power instability problem affects the economy growth, productivity and infrastructure development. The issues of phase failure, losses and phase imbalance earth fault are main causes that lead to unstable and erratic power supply. Most homes and office complexes where single-phase supply is needed are supplied with three phases of power supply to allow change from one phase to another when there is fluctuation or complete outage of power supply on a particular phase. This operation is normally done manually and has caused a setback in terms of time wastage, strenuous operation, susceptibility to fire outbreak, electric shock and high maintenance frequency. When voltage supply on a phase is below 220V or above 415V, this system automatically disconnects the load from the phase and connects to another where the required condition is met. Therefore, this paper presents a Microcontroller Based Automatic Transfer Switching System which is made up of voltage sensing circuit, Hall Effect current sensor, relays, LEDs and LCD of PIC16F877A microcontroller. A system flow chart was developed, programmed with MikroC software and simulated using Proteus electrical software design. A 10KVA single phase generator was used as alternate power source. The load capacity of the design was determined by decoupling Maxwell’s Equations of 8KW and power loss using pointing vector equation as 0.25% of the peak load. The switch is tested to have function optimally within ±5% nominal voltage of 220 - 415V supply and produced approximately 20 seconds elapses during the entire process of power supply changeover. Hence this device is suitable for Industrial and Domestic use where 3-phase power supply is available with a stand-by power source
IOT in Smart Villages: Challenges and Prospects
Get PDFSmart villages, which use the Internet of Things (IoT), offer a viable solution to the issues that rural communities confront around the world. This study provides a complete overview of the role of IoT technology in transforming rural communities into long-term, technologically advanced centers. It investigates the fundamental elements of smart villages, such as renewable energy, digital connection, agriculture, healthcare, and community interaction. It also addresses the benefits, constraints, and future prospects of using IoT in smart village programs. This research will analyze existing literature and case studies to provide insights into the potential benefits and best practices for using IoT solutions in rural development
Electromechanical analysis of a machine
Get PDFOutput performances such as induced-voltage and torque of an electric machine are investigated in this study, with particular reference to its pole number effects. The analyses are made using 2D-finite element method. The study revealed that the investigated machine having 6 stator slots and 11 pole number i.e. 6S/11P has the highest amount of magnetic remanence, coercive force and flux linkage amongst the compared machine types. Consequently, these highest values would yield the largest output torque in the machine. Desirably, high output torque is also relatively realized in the 6S/13P machine type. Nevertheless, both the 6S/11P and 6S/13P machine types would be adversely affected by large effect of magnetic force on its rotor. The greatest field-weakening ability, determined as a measure of the machine’s speed ratio is provided by 6S/13P machine topology and this trait is desired in traction and propulsion systems. The most competitive torque is also obtained from 6S/13P machine, considering its yield with respect to the employed magnet volume
Synthesis and characterisation of CaO nanoparticle from oyster shell using sol-gel method
Get PDFBecause human activity is constantly increasing the content of heavy metals, heavy metal removal becomes a major challenge in wastewater treatment. In an attempt to provide an innovative and sustainable option for addressing the said challenge, this study is aimed at the synthesis and characterization of nano-based CaO biosorbent from oyster shell. The sol- gel method was used to synthesize the biosorbent, characterized using FTIR, XRD, SEM and BET respectively. From the analysis conducted, the developed CaO nanoadsorbent has a point of zero charge of 5.6, indicating stable charge balance. The biosorbent was chemically characterized by the presence of a number of functional groups, most notably the –OH and C-H. The CaO nanoadsorbent was found to be crystalline in nature as revealed by XRD analysis. Findings from the BET indicated the material has a surface area of 344.528 m2/g, specific pore volume of 0.170cc/g and pore diameter of 2.118nm, indicating that it is mesoporous structurally. The results of the characterization reveal that the CaO nanoadsorbent present a suitable option for treatment of wastewater based on its associated attributes
Implementation of a sustainable real-time air quality monitoring system using the Internet of Things for Kaduna metropolis, Nigeria
Get PDFThe environment is sustainable if it is free of air, water, and soil pollution. This agrees with the United Nations Sustainable Development Goal Three (SDG3). However, urbanization and industrialization have aggravated the rise of air pollution which are hazardous to both human health and society. Ingestion of large quantities of air pollution gases is one of the greatest health risks in the environment which often leads to death, brain damage, and loss of consciousness at high doses. Some common sources of carbon monoxide (CO), the most severe of these gases, can be traced to the incomplete combustion of cars’ fuel, malfunctioning equipment, clogged chimneys and vents, and interior use of portable generators. Traditional ways of monitoring pollution are laborious and involve inefficient processes. To address this challenge, this paper implemented a real-time Air Quality Monitoring System using the Internet of Things (IoT) to measure the concentration of CO. The IoT devices were used to collate data within specific areas. The data collected, by the sensor, were processed using software which is then trained in the system to predict air pollution levels based on historical data. The system also includes a user interface that allows users to view real-time air pollution data and receive alerts when pollution levels exceed the safe threshold. The system was tested in different environments, Air Force Institute of Technology and Kawo; densely populated areas of Kaduna State, Nigeria. This was done to demonstrate the high level of accuracy and reliability of the system. The correct implementation of the developed system has the potential to be used as a tool for researchers, and for the general public to better understand and address the problem of air pollution
31W Linear broadband 3.4 to 4.4 GHZ high power class-j GaN HEMT amplifier
Get PDFThe recent upsurge in wireless communication systems requiring high-power transmitters for numerous applications such as electronic warfare (EW), RADAR, Satellite and optical communications has further underscored the importance of linear broadband high-power Class-J power amplifiers. This paper proposes a 31W linear broadband 3.4 to 4.4 GHz high-power Class-J GaN HEMT(gallium nitride high electron mobility transistor)amplifier. The power amplifier was designed based on Cree's commercially available 10WGaN HEMT power transistor device (CGHV40010F) using Keysight Advanced Design System (ADS) software and simulated. The transistor was biased withadrain supply voltage of 48V at aquiescent drain-to-source current of 0.58A,which makes the power transistor suitable for high voltage transmitter operations and foreclosed the need for voltage upgrade, thereby reducing thecost of operation. The power amplifier (PA) operates from 3.4 to 4.4 GHz with a centre frequency of 3.9 GHz. The PA has an output power of 31W, drain efficiency of 36.3%, power added efficiency of 35.3% and power gain of 12.9 dB at an input power of 32 dBm. The PA small signal gain stood at 10.6 dB at acentre frequency of 3.9 GHz. The PA maintained a peak envelope power of 56.2W at aninput power of 31 dBm at atwo-tone Frequency of 3.895 GHz. The proposed PA will find applications in wireless communications, military and aviation transmitters
AN IMPROVED CRYPTO-STEGANOGRAPHIC TECHNIQUE FOR DATA HIDING USING MODIFIED LEAST SIGNIFICANT BIT AND RIVEST SHAMIR ADLEMAN ALGORITHMS
No full textThis study is aimed at developing an improved LSB technique by overcoming the standard LSB technique's high imperceptibility and transparency, especially in JPEG and BMP formats which are the characteristics of a truly secure and reliable security technique for remote data transmission.
The standard LSB was modified to create a balance between the algorithm's exploration and exploitation stages so as to improve quantity solution in detecting high energy coefficient (optimal wavelet coefficient) of DWT and to resolve conflicting requirements of different parameters and properties of digital images. The techniques achieved improved Average difference, Mean Square Error (MSE), Root Mean Square Error (RMSE), Peak Signal to Noise Ratio (PSNR), Image Fidelity and Normalized Cross Correlation (NCC), indicating a higher quality measurement between the original and compressed images using different formats
Estimation and forecast of methane emission from Solid Waste Generation within LAUTECH, Ogbomoso, using IPCC Model and LANDGEM
Get PDFEstimation and prediction of methane emissions from various sources have become crucial for understanding their environmental impacts, preparing effective reduction plans against their hazards or converting them to be useful. This project examined the emission of methane gases from solid waste in open dumps at Ladoke Akintola University of Technology (LAUTECH), Ogbomoso, Southwest Nigeria. Methodologies from the well-established Landfill Gas Emission Model (LandGEM) and the Intergovernmental Panel on Climate Change (IPCC Model) were used for calculating the production of methane (CH4) gas, a greenhouse gas, with defined data, study areas, and assumptions clarifications. The results from the calculations and points for consideration are then laid out. Several open dumps were defined for these two models based on zones. The results revealed that there is a negligible existence of methane emissions in LAUTECH campus, with the IPCC model and LandGEM showing 1.5617E-04 Mg/year and 3.877E-07 Mg/year, respectively, at the end of the study years
A viable prototype device for air quality and heart rate monitoring using Internet of Things (IoTs)
Get PDFAir pollution poses a serious risk to everyone's health and well-being, especially the health of young people, the elderly ones, and people who have trouble breathing. All contaminants, such as gases, particulate matter, carbon monoxide, sulfur dioxide and biologically generated particles that are found in the atmosphere are referred to as air pollutants. The traditional ways of monitoring pollution are quite laborious and inefficient enough. It is pertinent to mitigate the excessive air pollution that is detrimental to people's and other living things' health. This bring motivation to carried out the objective of developing a device, an air pollution detector (APD) that monitors and measures both the quality of air and heart rate in a given environment. The IoT devices were used to collate data within a geographical area. The air data collected through MQ 135 sensor were calibrated and processed using Arduino programming language. The LCD module displays the air pollution data with the pulse of heartbeat in beats per minute (BPM) once the air gets denser. The system was tested in different five location on school's campus environments at Lead City University, Ibadan, Nigeria. Two sets of tests were carried out to measure air quality index (AQI) and the pulse. The tests carried out were based on the effect of time of day on AQI and heart rate (HR) in action and resting heart rate (RHR) respectively taking one-hour intervals from 8am to 8pm. The obtained sensitivity results showed that, a higher concentration of air pollution leads to an increase in heart rate and a lower concentration of pollution leads to a decrease in heart rate. Hence, the affordable and eco-friendly developed system has the potential to be used as a tool to explore for researchers, students and bringing awareness on the types of air pollutants for the general public
CHARACTERIZATION OF PELLETS PRODUCED FROM RICE BRAN AND CORNCOB
Get PDFProduction of pellet from biomass as gained interest of researchers in recent times due to their carbon-neutral characteristics. Problems such as low density and bulkiness inhibit their use as solid biofuels. This study produced and characterized pellets from rice bran (RB) and corncob using a pelleting machine. RB was collected from a rice milling factory in Ilorin, Nigeria and corncob was collected from a farm in Ogbomoso, Nigeria. The corncobs were hammer milled. Then both the hammer milled corncob and RB were sieved with BS 14 sieve and mixed with starch additive at 5% by weight. Pellets were then produced from the starched RB and corncob. The pellets produced from both materials were evaluated for pellet length, bulk density, proximate composition (moisture, ash, volatile matter and fixed carbon contents) and higher heating value. The mean values of pellet length, bulk density and moisture, ash, volatile matter and fixed carbon contents and higher heating values were: (39.90 mm, 0.367 g/cm3, 14.30%db, 32.60%, 18.20% 34.90% and 17.69MJ/kg) and (14.90 mm, 0.166g/cm3, 11.60%db, 72.10%, 14.30%, 2.00% and 16.92 MJ/kg) for RB and corncob pellets, respectively. The results revealed that both materials can be used as raw material for solid biofuels