LAUTECH Journal of Engineering and Technology (LAUJET)
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Determination of wear resistance, frictional power loss, and thermal conductivity of aluminium metal composites
No full textThis study addresses the need for lightweight, wear-resistant aluminium alloys in the automotive industry to combat climate change. Here, aluminum composites reinforced with various combinations of silicon carbide (SiC) and aluminum oxide (Al2O3) were fabricated from recycled aluminum cans using stir-casting. Wear resistance, thermal conductivity, and frictional power loss were evaluated. The serial tests of frictional power loss, thermal conductivity, and wear resistance results on PA, CS, 4% SiC-2%AO, 4% SiC-4%AO, 4% SiC-6%AO, 4% SiC-10%AO, and 6% RHA/4% PSA samples are the following: 1000, 1000, 850, 750, 550, 450, and 550 watts; 270, 260, 220, 200, 180, 125, 185, and W/m-K; and 0.24, 0.18, 0.3, 0.23, 0.12, 0.06, and 0.24 mg, respectively. The 4%SiC/10%Al2O3 composite demonstrated superior wear resistance against plastic deformation, minimal frictional power loss, and the highest thermal conductivity among the tested samples. This improvement is attributed to a wear-reacted layer formed during testing. Interestingly, the 4%RHA/6%PSA composite, utilizing alternative reinforcements, offered comparable thermal conductivity to other SiC/Al2O3 combinations, suggesting potential for further exploration. This research promotes the use of recycled materials while achieving the desired properties for sustainable automotive application
Urban soil infiltration rates on different land use types in southwest Nigeria: actual versus model estimates
Get PDFAs urban development increases and rainfall patterns become more highly variable, rainwater management issues are becoming increasingly prevalent. Given that urban soils may experience greater compaction than non-urban soils, infiltration models may not accurately represent disturbed urban soils, and this might jeopardize computations that rely on these models. Therefore, the objective of this research was to quantify the rates of soil infiltration on various urban land use types and assess the effectiveness of Horton and Green-Ampt infiltration models for application in urban soil environments. At 88 locations (23 commercial, 15 institutional, 36 residential, and 14 urban agricultural locations) spread across Akure metropolis, southwest Nigeria, soil infiltration rates and the soil's characteristics (texture, compactness, and moisture content) were examined. The highest infiltration rates were found in institutional (16.20 ± 9.73 cm hr-1) and urban agricultural (17.51 ± 10.38 cm hr-1) soils; nevertheless, all our data show that Akure's urban soils can infiltrate most rainfall episodes. The modeled and measured infiltration rates compare poorly, with both the Horton and Green-Ampt models underestimating the rates of infiltration of urban soil. When it came to estimating infiltration capacities, both models fared better in moist compared to dry soils and in loamy compared to sandy soils. Regarding the loamy soils, infiltration on the non-compacted soils was more accurately predicted compared to the compacted soils, according to both models, while the reverse was the case for the sandy soils. The models' largely below-average performance in urban soils will probably make projections from the models less reliable. The results of this study demonstrate the necessity of creating more reliable, enhanced infiltration models that work with urban soils
EFFECT OF GUM ARABIC BIOPOLYMER ON THE ATTERBERG LIMIT AND CATION EXCHANGE CAPACITY OF LEAD- CONTAMINATED LATERITIC SOIL
Get PDFLaboratory tests and regression analysis were used to assess the liquid limit, plastic limit, and plasticity index, as well as cation-exchange capacity (CEC) of the contaminated lateritic soil treated with up to 25% Gum Arabic biopolymer (GAB). Tests conducted on the soil sample include specific gravity, Atterberg limit, particle size distribution, and cation exchange capacity (CEC). The findings indicate a rise in cation-exchange capacity up to 25% GAB content, while the liquid limit, plastic limit, and plasticity of the lead-contaminated soil decreased with an increase of up to 10% GAB content. However, regression analysis of test results shows a strong correlation between the experimental and predicted values. The consistency indices for use as a subgrade material on lightly traveled roads were improved by a 10% GAB content blend with contaminated lateritic soil. 
Gas turbine bearing vibration monitoring using potable vibrometer
Get PDFThis paper focuses on the use of potable vibrometer to undertake gas turbine condition monitoring and fault detection of an industrial gas turbine power plant in Ajaokuta, Nigeria. Validation of the potable vibro-meter readings is done by comparing results obtained using the potable vibrometer with results gotten from the plant vibrometer transducers. After comparing bearing vibration amplitude results at the gas turbine exciter and generator ends, results for the test case looked at indicate that very good correlation exist between the two readings (above 90%). Conclusion reached is that measurement accuracy of the potable vibrometer reading is highly dependent on the visibility of the component measured and their corresponding vibration measurement sensors (Accelerometers and velocity meters).
Key words: Ajaokuta, Potable Vibrometer, Fluke, Geregu power
Efficiency of water hyacinth and cattail for wastewater treatment using constructed wetland
No full textABSTRACTConstructed wetlands have emerged as a cost-effective, eco- friendly and sustainable solution to enhance water quality by effectively removing nutrients. The objective of this study is to compare water hyacinth (Eichhornia crassipes) and Cattail (Typha latifolia) as wetland plants for wastewater treatment at the National Water Resources Institute (NWRI) situated in Kaduna State, Nigeria. The percentage removal of various parameters including pH, Total Dissolved Solids (TDS), Turbidity, Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Phosphorus, Nitrate, Ammonia, Sulphate, Oil and Grease, Total Coliform, Feacal Coliform, Copper, Zinc, Iron and Lead were compared for cattail and water hyacinth. The results of the analyzed parameters were compared with the Food and Agricultural Organization of United Nations (FAO, 2015) limits for irrigation purposes. Results showed pH, TDS, Turbidity, TSS, Sulphate, Nitrate, BOD, COD, FC, and Iron, Copper, Lead and Zinc were within permissible limit of the standard for irrigation water quality according to FAO, while EC and Total Phosphorous were above the maximum permissible limit. The result of the percentage removal efficiency showed that water hyacinth had higher performance in removing the pH (13.34%), Turbidity (97.24%), Sulphate (100%), Nitrate (18.51%), Total Phosphorous (96.34%), COD (86.21%), BOD (77.92%), Oil and Grease (73.80%), FC (78.48%), TC (36.24%), Copper (81.84%), Lead (89.69%) and Zinc (79.38%) compared to typha latifolia. For 82.61% EC, 82.09% TDS, 94.51% TSS, 97.31% Iron and removal, efficiency of typha latifolia was higher. Constructed Wetland vegetated with typha latifolia and Eichhornia crassipes showed high contaminant removal efficiency with water hyacinth showing superior removal efficiency
Investigating the impact of solvent extraction parameters on oil yield and oil properties: a review
No full textOilseeds are rich in fatty acids, proteins, fibers, minerals, and vitamins that are necessary for human health. It mainly comprises triglycerides and other minor components, including phytosterols, phenols, carotenoids, tocopherols, and phospholipids. Oils can be extracted using a variety of extraction methods including but not limited to the conventional mechanical and solvent method, and novel methods like supercritical fluid extraction. However, the quality and quantity of extracted oil depends on the process parameters. Among many process parameters temperature is the main parameter which controls the yield and its quality. Temperature range depends upon the nature and type of oilseed. High temperature leads to increased yield while relatively low temperature results in low oil yield and longer extraction time. Large particle size of the solid creates a temperature gradient between the inner and outer surface of the seeds which in turn lowers oil yield. Based on this review, an extraction temperature slightly below the boiling point of the solvent is recommended.  
Performance evaluation and redesign of Offa garage roundabout in Ilorin, Nigeria using microscopic simulation
Get PDFAn urban traffic system is a composite network, which consists of varying types of intersections. In this paper, the focal point is on a heterogeneous traffic system, In this paper, the focus is on a heterogeneous traffic system featuring a non-signalized intersection (roundabout), with the aim of replacing it with a signalized one
It has always been a difficult process to carry out Traffic analysis, with the ever increasing volume of vehicles and densely populated roadways. it is definitely difficult to suggest an alternative answer especially in developing countries like Nigeria. This paper analyses an intersection in the city of Ilorin Kwara State Nigeria. The intersection is modelled with the VISSIM 21, which is a traffic microscopic simulation software that has been extensively used in assessing traffic conditions. The paper also simulates the modelled intersection and determines the possibility of installing a traffic signal at the skewed T- intersection and checks its usefulness by comparing the Level of service, Queue length and carbon emission when the signals is installed and after
A Simulation study of the output characteristics of freestanding Triboelectric nanogenerators with interdigitated electrodes for self-powered sensing application
No full textDiverse forms of mechanical energy are available in environmental routine activities. These energy forms can be harvested, measured and converted to produce electricity at nanogenerator (NG) and micro-scale levels based on the phenomenon of triboelectrification. These motivate this work to develop a self-powered sensing device to detect and monitor static and dynamic processes associated with mechanical activities. The significance is to study the output characteristics of freestanding mode triboelectric nanogenerator (TENG) with multiple units of metal and dielectric electrodes. The integrated modeling environment of COMSOL Multiphysics software was employed for the simulation study of the proposed TENG. The system output responses considered for analysis includes, open circuit electric potential and short circuit surface charge density. For the open circuit, the electric potential was achieved at maximum value of 10kV, while for short circuit surface charge density, the electric potential was achieved at maximum value of 27 Cm-2. The study results revealed that the input parameter of contact displacement of electrodes is proportional to the output electrical potential of the system. Hence, the efficiency of TENG can be deployed for energy harvesting and sensing of mechanical variables
DEVELOPMENT OF A DECENTRALISED MODEL FOR ELECTRONIC EXAMINATION PASS USING BLOCKCHAIN TECHNOLOGY
Get PDFConventional examination pass systems face persistent challenges of security breaches and administrative inefficiencies due to the centralised nature of these systems. There is need to address the problem of centralisation to enhance the security of these system and fortify the integrity of the examination process by mitigating the risks of data manipulation and unauthorized access. This study introduces a decentralised framework, powered by Hyperledger Fabric private blockchain, to revolutionize examination pass management
APPLICATION OF MACHINE LEARNING TO TEXT CLASSIFICATION
Get PDFThe information superhighway provides important principles for giving out information to various consultations. Organizations depend on knowing customer observations about products and services. Data can be enormous to process physically. This study investigates a technique applying Python programming to collect datasets instinctively. The use of machine learning models evolves by applying Random Forest and Naïve Bayes algorithms. These techniques are applied to the data collected for text classification purposes. This process distributes data into; positive, negative, slightly negative, slightly positive, or neutral. The results from the study show the Random Forest classifier is more efficient than the Naïve Bayes algorithm, resulting in an accuracy rate of 76.5% about Naïve Bayes (70.01%). This technique enables organizations to receive insights into customer ways of thinking