LAUTECH Journal of Engineering and Technology

CHARACTERISATION OF THE ELASTIC PROPERTIES OF SOILS IN SOME PARTS OF LAGOS WETLANDS FOR ENGINEERING PURPOSES

H. T. Oladunjoye — 2022-04-07

The results obtained from the evaluation of elastic properties of some part of Lagos Wetlands were presented for the determination of the competent soil for engineering structures. The study area falls within the reclaimed part of the Lagos wetlands signifying the presence of unstable geological materials. The study area is characterized with alluvium sediments which comprises of materials of low shear strength. Five (5) seismic profile lines were established via the ground rolling technique of Multi-Channel Analysis of Surface Waves (MASW). The data acquisition was carried out with twenty-four (24) channels 4.5Hz vertical geophones connected to the ABEM Mark 6 Terraloc Seismograph. The acquired MASW data were processed using SeisImager to obtain the two-dimensional (2-D) shear wave velocity (V_s) profiles which gives the contrast in the distribution of the velocity along each profile. In addition, dynamic parameters such as rigidity modulus, poisson ratio were estimated for further classification of the geo-earth materials in the study area. In the study area, the shear wave velocity (V_s) values obtained ranged between 94 – 1320 m/s representing different sediments such as saturated loose sand (163 – 204 m/s), loose silty sand (165- 225 m/s), medium – dense sand (220 – 350 m/s), medium dense sand (400 – 700 m/s) and dense-coarse sand (900 - 1380 m/s). However, based on these classification, it is found that saturated loose sand and loose silty sand are not competent for founding layer of engineering structures. Therefore, deep foundation inform of piling system is recommended for engineering structure that will devoid unexpected collapse and partial and differential settlement. The study has revealed that the area is generally comprise of problematic soil(s) that are inimical to construction of engineering structures.

DEVELOPMENT OF A CLOUD BASED STUDENT INFORMATION CHATBOT SYSTEM

K. O. Jimoh — 2022-04-07

The development of chatbot system is an algorithm that analyzes the student queries and reply messages. In this system, artificial intelligence is built to answer the query of the student. The specific objectives are to determine the required features for the construction of knowledge base, design and implement the model, evaluate the performance of the developed system. Samples of Frequently Asked Questions (FAQ) was collected from the department of Student Affairs, Admission Office and Information Management and Technology Center (IMTC) of the university. The collected sample was analyzed based on the category of question and the model was designed using Unified Modeling Language (UML). The model was implemented with python programming language, HTML, CSS, JavaScript for the client sever side, and also Artificial Intelligence Markup Language (AIML) () and MySQL for the back end. The developed system performance was evaluated using Alpha Beta testing. The proposed system was successfully tested to denote its effectiveness and achievability. It totally eliminates the manual process of retrieving information about a particular domain and reduces manpower, time, for any individual. The developed system will provide adequate assistance to the student on FAQ, thereby reducing the time in visiting the college to enquire about the information in respect of school activities. It will also provide an enabling environment for the students to keep them updated about the school activities.

DEVELOPMENT OF A RECHARGEABLE ELECTRONICALLY CONTROLLED MOTORISED WHEELCHAIR FOR DISABLED AND ELDERLY PEOPLE

K. M. Adeleke — 2022-04-07

The 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 ones

PROJECTION OF CRITERIA AIR POLLUTANTS EMISSION FROM ON-ROAD VEHICLES IN THE MEGACITY OF LAGOS, NIGERIA

R. O. Yusuf — 2022-04-07

The 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 (SO_x), particulate matter (PM), lead (Pb), carbon monoxide (CO), and nitrogen oxides (NO_x). 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: SO_x: 209–15,358t, NO_x: 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 SO_x, 22,600 – 41,300t for NO_x, 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.

MODELLING OF GROUND LEVEL CONCENTRATION OF PARTICULATE MATTER IN MAJOR NIGERIAN UNIVERSITY AIRSHED

R. O. Yusuf — 2022-04-07

Modelling 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 ambient

DEVELOPMENT OF A MODIFIED EMPIRICAL MODEL FOR NEW MOBILE RADIO NETWORK AT 28 GHZ MILLIMETER WAVE SPECTRUM

Akinyinka Olukunle Akande — 2022-04-07

Quality of received signal depends partly on the degree of loss the signal experiences along its path. Different models are available for network path loss (PL) prediction. The issues of poor network in some urban area need special attention especially during the deployment of 5G new radio network. It is believed that 4G and 5G networks will coexist for a very long time. 5G network will work in conjunction with the existing 4G network, and 4Gnetwork is not going away any time soon. Hence, it is important to develop a suitable model to mitigate the outcome of signal attenuation and signal interference in 5G network. This paper presented a modified particle swarm algorithm model in 4G network at 28 GHz millimeter wave spectrum. Some existing PL models are unsuitable for PL prediction in certain environments necessitating the development of an appropriate model. To achieve this, existing models and measured data were compared to find out the closest model to the measured value. The environmental loss exponent was obtained to modify Okumura-Hata which is the closest model to the measured path loss (PL) data. A new modified model for the terrain was enhanced by the developed Autoregressive Particle Swarm Optimization (APSO) Algorithm. Root Mean Square Error (RMSE) results obtained are 4.499 dB, 1.050 dB and 0.872 dB for Okumura-Hata, Modified and Enhanced model, respectively. The corresponding values for Mean Absolute Percentage Error (MAPE) are 0.254 %, 0.058 % and 0.048 %. The result showed that Enhanced APSO is a suitable model for predicting 4G network in Abuja, Nigeria

DESIGN, FABRICATION AND EVALUATION OF DIGITAL TILT TEST DEVICE

Musa A. Idris — 2022-04-07

Due to the high and fluctuating exchange rate, obtaining devices and equipment for practical demonstration of theoretical contents of engineering and applied science courses in developing countries is becoming a herculean task. To sustain the practical aspect of these courses, some of the devices have to be locally manufactured. In this study, a digital tilt test device for determining the basic friction angle and joint roughness coefficient (JRC) of rock samples was designed and fabricated using majorly local materials. Comparing the device's results with those obtained from the Profilometer, there was a satisfactory correlation between the two results. The device is much cheaper to manufacture locally than the imported onesTherefore, it is recommended that the device be used for estimating the friction angle and JRC of rock samples. Similar devices with simple mechanisms should be manufactured locally in higher institutions to reduce dependency on foreign devices, which are expensive.

SELECTED MECHANICAL PROPERTIES OF BAMBARA GROUNDNUT SEEDS UNDER COMPRESSIVE LOADING

A. K. Aremu — 2022-04-07

Knowledge 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.

TEXTURE MODELING AND SIMULATION FOR SYNTHETIC PALM VEIN IMAGE GENERATION SYSTEM

Olajide Y. Adebayo — 2022-04-07

Unavailability of large-scale palm vein databases due to their intrusiveness have posed challenges in exploring this technology for large-scale applications. Hence, this research modelled and generated synthetic palm vein images from only a couple of initial samples using statistical features. Variations were introduced to the three optimized statistical features (S5; the original images were employed as training images and the best variation in the first experiment as training images, S4; the best variation in the first experiment as training images while the original images were used as testing images, S3; mean vectors, covariance matrices and correlation coefficient, S2; mean vectors and covariance matrices, S1; mean vectors, Non-Synthetic; acquired image) which were used to generate synthetic palm vein images employing statistical and Genetic Algorithm (GA) approaches and were evaluated based on Equal Error Rate (EER), Average Recognition Accuracy (ARA) and Average Recognition Time (ART). The results obtained from the experiment showed that EERs were 0.22, 0.51, 0.58 and 4.36 for S3, S2, S1 and NS respectively. S3 had superior ARA (99.83%) compared with S2 (99.77 %), S1 (99.70 %) and NS (98.33 %). The ARTs obtained were 84.97s, 75.55s, 84.04s and 681.74s for S1, S2, S3 and NS respectively with S2 (75.55s) having significantly least value. Furthermore, EER, ARA and ART for S4 were 0.43, 99.00%, and 12.13s, respectively while the corresponding values for S5 were 1.43, 97.50%, and 680.13s, respectively. The research outcome justifies the extraction of mean vectors, covariance matrices and correlation coefficient.