LAUTECH Journal of Engineering and Technology (LAUJET)
Not a member yet
571 research outputs found
Sort by
PROPERTIES OF LIGHT WEIGHT CONCRETE BEAM EMBEDDED WITH EMPTY CYLINDRICAL TIN WASTES
Get PDFThe search for new construction materials is on the increase due to the overwhelming environment wastes generated and dumped in the surroundings. This research is focused on environment littered with Empty Cylindrical Tin Wastes(ECTW) which poses environmental problems (pollution)and the cost of reducing such waste is alarming.This research tests the viability of these wastes as construction materials. Modulus of rupture (MoR), density, absorption and deflection tests were carried out on the samples of beams embedded with ECTW below the neutral axis. The results from the tests carried out showed a promising strength, reduced deflection and better physical properties as compared with the conventional beam samples for the curing periods of7, 14, 21, and 28days.The results also revealed that the use of ECTW as embedded materials in the concrete beam samples will yield an economy of 29.33%. It was concluded that ECTW can serve as a new construction material for light weight structures thereby reducing environmental wastes, pollution and cost of disposal of such waste
DIFFERENTIAL MATURITY ACROSS LATERITIC PROFILES FROM ILORIN, NORTH CENTRAL NIGERIA
Get PDFThis 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 performanc
EXPLORING SOURSOP KERNEL AS A SUSTAINABLE BIOFUEL: ANALYZING PHYSICAL AND SOLID FLOW PROPERTIES FOR FEASIBILITY ASSESSMENT
Get PDF Soursop kernel is an oil-bearing seed containing about 25% non-edible oil per 100 g sample making it a potential feedstock for biofuel production. However, exploring the full potential of the oil requires data to design and fabricate appropriate machines for its processing. So, this necessitates a thorough examination of its physical and solid flow behaviour in relation to moisture contents. The experiments conducted on rewetted samples revealed that as moisture content (mc) increased from 8% to 32.5% dry basis (db), the length, width, thickness, arithmetic and geometric mean diameter, volume, surface area, sphericity, and thousand kernels weight increased from 11.40-12.06 mm, 7.04-7.92 mm, 4.58-5.34 mm, 7.69-8.44 mm, 7.12-7.49 mm, 6.5–8.13 cm3, 160.19-199.05 mm2, 0.62- 0.66 and 186.4–291 g, respectively. The true density decreased from 720 to 670 kg/m³, whereas the bulk density increased from 470 to 570 kg/m³. The angle of repose linearly increased from 25.8° to 39.2° as moisture content increased. The highest mean values for coefficients of friction were observed on mild steel surfaces (0.44 for static and 0.53 for dynamic) at 8.0% mc (db) while the lowest values were recorded on stainless steel surfaces (0.20 for static and 0.37 for dynamic) at both 32.5% and 8.0%, (mc, db). The data obtained will prove beneficial to engineers in the design and development of appropriate machines, as well as other handling and processing equipment such as oil expellers, so as to explore the full industrial application of the oil for biodiesel production and other chemical productio
SELECTED MECHANICAL PROPERTIES OF BAMBARA GROUNDNUT SEEDS UNDER COMPRESSIVE LOADING
Get PDFKnowledge of mechanical properties of agricultural materials is useful in the development of equipment for processing and handling them.Selected mechanical propertiesnamely rupture force, maximum deformation at rupture point, hardness and toughness of cream and light brown varieties of Bambara groundnut (BGN) seeds were determined at four moisture levels (5, 15, 25 and 35% dry basis) under compressive loading alongaxial and longitudinal orientations.Rupture force, deformation, hardness and toughness of BGN seedswere within the ranges 45.58-438.55 N, 0.31-5.71 mm,14.61-448.55 Nmm-1 and0.01-1.02J, respectively. Rupture force, deformation and toughnessof the seeds had interplay of increasing and deceasing trends while hardness decreased consistently as moisture content increased from 5% to 35%.The cream variety withstood higher rupture force and deformed more without failure than the light brown variety within moisture content range of 5-25% along both loading orientations.Bothvarieties demonstrated greater hardness when loaded along the longitudinal orientations than the axially loaded samples. All the investigatedproperties were dependent on moisture content andorientationof loading. Predictive mathematical models forestimating the investigated properties at different moisture contents with reasonable accuracy were also established in this study
DESIGN AND SIMULATION OF AN EFFICIENT MODEL FOR CREDIT CARDS FRAUD DETECTION
Get PDFIn this study a model which can improve the accuracy and reliability of credit card fraud detection was proposed. This is with a few to mitigating contentious issues regarding online transaction of credit card, such as amount of transactions that have resulted in payment default and the number of credit card fraud cases that have been recorded, all of which have put the economy in jeopardy. To address this challenge,sample dataset was sourced from online repository database of Kaggle. The feature extraction on the data was performed using Principal Component Analysis (PCA). The credit card fraud detection model was designed using Neuro-fuzzy logic technique, clustering was done using Hierarchical Density Based Spatial Clustering of Application with Noise (HDBSCAN) .The simulation of the proposed model was done in Python programming environment.The performance evaluation of the model was carried out by comparing the proposed model with Neuro-Fuzzy (NF) technique using performance metrics such as precision, recall, F1-score and accuracy. The simulation result showed that the proposed model (NF + HDBSCAN) had precision of 98.75%, recall of 98.70%, F1-Score of 97.65% and accuracy 99.75% . NF had Precision of 94.60%, recall of 94.50%, F1-Score of 95.50% and accuracy 95.70% using training dataset. Likewise, when test dataset were used, the proposed (NF + HDBSCAN) had precision of 93.50%, recall of 95.50%, F1-Score of 94.50% and accuracy 95.50%. NF had Precision of 92.50%, recall of 93.00%, F1-Score of 94.00% and accuracy 93.50%. The simulation results of the proposed model was viable, reliable and showed possibility of being designed as module which could be integrated into the existing credit card design for lowering fraud rate and assisting fraud investigators
EFFECT OF MECHANICAL AND PHYSICALPROPERTIES ON BRAKE PADS PRODUCED FROM BAGASSE, BANANA PEELS AND PERIWINKLE SHELL
Get PDFThe study examined the effect of some mechanical and physical properties on brake pads produced from bagasse, banana peels and periwinkle shell in order to determine the materials suitability to develop new asbestos-free brake pads.These materials were sourced locally at Ede, Osun state.Samples were produced from different mix ratios of constituents using two sieve grades of 180 and 250 ?m particle sizes. The percentage weights (wt%) of bagasse, banana peels and periwinkle shells were varied while those of crystalline silica, lead sulphide and epoxy resin were constant for both sieve grades. The density of each sample decreases from 2298 - 1199 Kg/m3 as the sieve grade increases. Also, the oil and water absorption rates increase from 0.007 - 0.022% and 0.012 - 0.037% respectively with an increase in sieve grade. Thehardness values of the brake pads produced range from 79.7 to 89.4 HRB and 77.1 to 84.8 HRB for both sieve grades, respectively. Likewise, the values of impact strength for the sieve grades ranged from 18.89 to 27.10J/mm and 17.97 to 24.85 J/mm, respectively.The samples B and C consisting of 15 wt% bagasse, 15 wt% banana peels, 30 wt% periwinkle shell, 10 wt% crystalline silica, 10 wt% lead sulphide, 20 wt% resin and 15 wt% bagasse, 30 wt% banana peels, 15 wt% periwinkle shell, 10 wt% crystalline silica, 10 wt% lead sulphide and 20 wt% resin for sieve grade of 180 ?m, respectively, were regarded as the best among others because they gave the greatest properties. Therefore, the study concluded that the use of bagasse, banana peels and periwinkle shells as reinforced materials have properties suitable for the production of brake pads
SENSITIVITY ANALYSIS OF HYBRIDIZED WIND/PV ENERGY SYSTEM FOR POWERING TELECOMMUNICATION MAST IN LAGOS SOUTH-WEST NIGERIA
Get PDFPower 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 Hybrid Optimization Model for Energy Resources (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
PROJECTION OF CRITERIA AIR POLLUTANTS EMISSION FROM ON-ROAD VEHICLES IN THE MEGACITY OF LAGOS, NIGERIA
Get PDFThe increase in the mode of transportation has become a serious environmental threat that has resulted in the emission of criteria air pollutants (CAPs) into the atmosphere. These CAPs are sulphur oxides (SOx), particulate matter (PM), lead (Pb), carbon monoxide (CO), and nitrogen oxides (NOx). This study examined the emission of CAPs from road traffic use in Lagos State. Data for the inventories of the production of these five sources were taken from 1997–2011 and were used to forecast CAPs emissions from 2012–2030. The petroleum products consumption data were sourced from the Nigerian National Petroleum Corporation (NNPC). Five categories of CAPs were studied and their corresponding emissions from 1997–2011 were computed as follows: SOx: 209–15,358t, NOx: 2,038–25,692t, CO: 24,996–186,202t, PM: 155–995t, Pb: 0.8 4.5t. Projection and forecasting of CAPs emissions from 2012 to 2030 were carried out using the Box Jenkins ARIMA method. There were close similarities between the observed and forecast values. The predicted CAPs emissions between 2012 to 2030 will be 309t for SOx, 22,600 – 41,300t for NOx, 100,000 – 300,000t for CO, 414t for PM, and 0.7t for Pb. The study concluded that there is tendency for these CAPs emissions to increase if the authorities and stakeholders do nothing. Several mitigation measures aimed towards reducing future CAPs emissions in Lagos State were recommended for the various sources
DEVELOPMENT OF A RECHARGEABLE ELECTRONICALLY CONTROLLED MOTORISED WHEELCHAIR FOR DISABLED AND ELDERLY PEOPLE
Get PDFThe physically challenged, old-age people, and most paralysed patients need means of transportation from place to place to ease their movement. The earlier available wheelchairs are manually driven that need extra effort of either the physically challenged or an assisting person to move. Nowadays, the level of communication and socialization strongly depends on easy access to mobile transportation. This paper presents a developed motorized wheelchair that facilitates movement of physically challenged people both in the hospital and in their home by taking into account aesthetics, low cost, ease on maintenance with market competitive advantage using locally sourced materials. The developed wheelchair is designed to work for 3 hours under a maximum load of 90 kg with navigation buttons. A working efficiency of 65 % was obtained under full operation. This design brings a new competition into the wheelchair market and gives more comfort to the physically challenged peoples’ mobility than the existing manually driven one
MODELLING OF GROUND LEVEL CONCENTRATION OF PARTICULATE MATTER IN MAJOR NIGERIAN UNIVERSITY AIRSHED
Get PDFModelling of air pollutants for air quality assessment has been an important landmark achievement by environmentalists especially in areas where on-the-field monitoring is not economical. Models have proven to be cost-efficient and predicts better with different sample sizes. The objective of this study was to model the particulate matter pollutants of a major Nigerian university airshed and to compare of the predicted results with regulatory standards. Dispersion modelling analysis using for line and point sources study of the university airshed was carried out. Prior to the use of the modelling tool, vehicular counts, emission estimation and loads for the two pollution sources was done. The predictions revealed that concentration levels of PMs to emission source and receptor environments for the line source study were extremely high due to factors such as emission height and meteorological conditions of the university. The predicted concentrations from the point source were moderate and the reason is due to the emission height (stack height), wind speed and direction. Other contributing sources could be as a result of biomass burning, bush burning and pollutant transport. This study will be a bedrock for institutional-based air quality assessment that checkmate the anthropogenic contribution to deteriorating ambien