LAUTECH Journal of Engineering and Technology (LAUJET)
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MICROBIAL FUELCELL TECHNOLOGY: PROSPECTS FOR WASTEWATER TREATMENT AND TACKLING ELECTRICITY CHALLENGES IN NIGERIA
Get PDFTreating wastewater is very critical for preserving the quality of surface and ground waters. It is estimated that there is about nine times more energy in the wastewater than was used to treat it. Nigeria’s power supply has continued to linger with its electrification rate less than half of the population and many parts of the country enmeshed in pitch darkness. Microbial Fuel Cells are an emerging technology that uses bacteria to generate electricity from wastewater. With this power source, clean sustainable energy can be produced at lower cost and thus, help to improve Nigeria’s current power supply challenges
IMPROVING THE STRENGTH PROPERTIES OF SUBGRADE SOILS WITH FLY ASH
Get PDFSubgrade soils encountered during road construction are not always good materials to respond to the imposed stresses which has become a dominating factor for the failure of pavements in Nigeria. The subgrade materials were sourced from three locations within South Africa namely, Heanertsburg Village (A), Laudium, South West of Pretoria (B), and Eskia Mphahele drive to Francis Baard Street, Pretoria (C). Fly Ash (FA) was added to samples A, B, and C at 3-12%, 5-15%, and 9-12% respectively. Sieve analysis, compaction, Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) tests were conducted on the virgin and stabilized soil samples for a curing time of 1, 7 and 28 days. The soils were classified as A-7-6, A-6 and A-2-6 according to AASHTO for samples A, B and C respectively. UCS and ITS was improved with the addition of FA to all the soil samples. The UCS results for sample A (406 kN/m2) and B (625 kN/m2) falls short of 1710 kN/m2 specified for cement stabilized base materials but 12% and 10% FA treated soils may be used as improved subgrade for flexible pavement construction. However, sample C result meets the requirement of 687-1373 kN/m2 for sub-base at 100% relative compaction. All the stabilized samples increase in ITS with respect to increasing curing days and FA. Only sample C attained to the specified ITS value. Therefore, FA can be used to improve the subgrade in order to withstand the imposed stress
EVALUATION OF ENTRANCE SKIN DOSE FOR ADULT PATIENTS UNDERGOING DIAGNOSTIC X-RAY EXAMINATION USING C-SHARP SOFTWARE IN SOME PROMINENT HOSPITALS IN OYO STATE, NIGERIA
Get PDFA total of 700 patients were surveyed using C-sharp software to determine entrance skin dose (ESD) of patients undergoing x-ray examination of the chest (PA/LAT/AP), cervical spine (AP/LAT), thoracic spine (AP/LAT), lumbar spine (AP/LAT) and pelvis (AP) in eight radiological units of both public and private owned hospitals. The study considered body weight 50-70kg adults. The patients’ characteristic and exposure parameters such as examination type, projection type, sex, age, weight, tube voltage (kV) and product of the current and time (mAs) were scripted into the software. The mean of the determined ESD were 0.27 mGy, 0.25 mGy, 0.38 mGy, 1.20 mGy, 3.07 mGy, 2.25 mGy, 2.02 mGy, 2.80 mGy, 3.35 mGy and 2.01 mGy and the mean effective doses as presented: 0.032 mSv 0.030 mSv, 0.046 mSv, 0.048 mSv, 0.015 mSv, 0.090 mSv, 0.242 mSv, 0.274 mSv, 0.402 mSv and 0.161 mSv for chest AP, chest PA, chest LAT, cervical spine AP, cervical spine LAT, thoracic spine AP, thoracic spine LAT, lumbar spine AP, lumbar spine LAT and pelvis AP respectively. The results were compared with published studies and international established diagnostic reference levels (DRLs)
ASSESSMENT OF SUBGRADE SOIL STABILIZED WITH CALCIUM CARBIDE WASTE, CEMENT KILN DUST AND STEEL SLAG
Get PDFPoor subgrade soil conditions can result to inadequate pavement support and reduce pavement life and such soil may be improved through the addition of chemical or cementation additives. This paper present assessment of weak subgrade stabilized with Calcium carbide waste (CCW), Steel slag (SS) and Cement kiln dust (CKD) in terms of Plasticity Index (PI), Maximum dry density (MDD), California bearing ratio (CBR) and Unconfined Compressive Strength (UCS). Curing was done in accordance with relevant specification for stabilized soils at 0, 7, 28, and 90 days. The result indicate that beyond 6% CCW shows no change in PI, thus 6% CCW can be designated as fixation point which was used to activate the pozzolanic effect of SS while the optimum value for CKD was at 15%. MDD decreases with increase in percentages of 0 – 20% CKD from 1.88g/cm3 to 1.74g/cm3 while it increases with increase in SS. Maximum CBR was achieved at 8% CCW corresponding to 111,119, 167 and 235% and CKD (15%) are 86, 96, 133 and 176% for 0, 7, 28, and 90 days respectively. UCS for SS and CKD at their optimum value for 7, 28 and 90 days were 1296.38, 1654.28, 2198.95 kN/m2 and 1148.04, 1364.38, 1800.99 kN/m2 accordingly. The CBR and UCS results showed that the stabilized soil at 7 days curing can be used as a sub-base material for pavement construction
FACIAL EXPRESSION RECOGNITION BASED ON CULTURAL PARTICLE SWAMP OPTIMIZATION AND SUPPORT VECTOR MACHINE
Get PDFFacial expressions remain a significant component of human-to-human interface and have the potential to play a correspondingly essential part in human-computer interaction. Support Vector Machine (SVM) by the virtue of its application in a various domain such as bioinformatics, pattern recognition, and other nonlinear problems has a very good generalization capability. However, various studies have proven that its performance drops when applied to problems with large complexities. It consumes a large amount of memory and time when the number of dataset increases. Optimization of SVM parameter can influence and improve its performance.Therefore, a Culture Particle Swarm Optimization (CPSO) techniques is developed to improve the performance of SVM in the facial expression recognition system. CPSO is a hybrid of Cultural Algorithm (CA) and Particle Swarm Optimization (PSO). Six facial expression images each from forty individuals were locally acquired. One hundred and seventy five images were used for training while the remaining sixty five images were used for testing purpose. The results showed a training time of 16.32 seconds, false positive rate of 0%, precision of 100% and an overall accuracy of 92.31% at 250 by 250 pixel resolution. The results obtained establish that CPSO-SVM technique is computational efficient with better precision, accuracy, false positive rate and can construct efficient and realistic facial expression feature that would produce a more reliable security surveillance system in any security prone organization
DEVELOPMENT OF A LOW COST RICE MILLING MACHINE
Get PDFRice is generally considered as semi aquatic annual plant that survives as perennial in the tropics or subtropics. The high cost of the available rice milling machine affects the production of rice in large quantity. Therefore, there is need for a low cost rice milling machine with high efficiency and reduced operating noise. A rice milling machine was developed consisting of the feeding unit, milling unit, cleaning unit, separating unit delivery unit and the frame. The rice milling machine has a capacity of 12 kg/hr and powered by a 3hp electric motor. The process of milling involves the interaction of machine and seed for the release of grains through blown air from impeller. The performance parameters include, percentage of broken rice, milling efficiency of paddy varieties, wholeness and machine efficiency which were evaluated at five different moisture content groups namely; A, 11.00-12.99%, B, 13.00-14.99%, C, 15.00-16.99%, D, 17.00-18.99% and E, 19.00-20.99%. Four varieties of paddy, NEL-42, NE 2, F55 and OFADA were used. The highest milling efficiency of 64 % was obtained for all varieties of paddy at A. The low percentage of broken rice and milling efficiency of 64% for paddy variety NEL-42 proved the effectiveness of the machine
COMPARATIVE ANALYSIS OF QUALITY OF SERVICE OF GSM NETWORKS IN NIGERIA: CASE OF IKORODU AND BADAGRY
Get PDFThe problem of poor quality of services as well as congestion in channels includes call setup failure, call retention/call drop and traffic congestion. In this study, the quality of services (QOS) of some selected operators of global system for mobile communications (GSM) networks in Ikorodu and Badagry network regions of Nigeria were investigated for six months. A benchmarking drive test method was employed in the collection of call data which included accessibility, retainability, mobility, coverage reliability, and coverage quality and call completion rate. Erlang and poison probability distribution models of call blocking rate and congestion control respectively were employed in the analyses to determine the probability of calls blocked and profound a solution to traffic congestion. The study of quality of services and a set of dimensions for comparative evaluations were analysed and compared with NCC targets. During Ikorodu region test, a total of 90 calls were made with operator A in which 69 were established and 21 were blocked, 90 calls were made with operator B, 49 established 41 blocked, a total of 88 calls were made with operator C in which 62 established and 26 blocked, 90 calls were made with operator D, 89 established and 6 blocked. At Badagry region a total of 274 calls were made with operator A in which 255 were established and 19 were blocked, 274 calls were made with operator B, 212 established 62 blocked, a total of 274 calls were made with operator C in which 191 established and 83 blocked, 274 calls were made with operator D, 205 established and 69 blocked. All calls event were recorded by the TEMS software, Molina lost calls held trunking formula (poison formulas) were established to compare and confirm these calls value. Generally the quality of services of the operators met up to NCC targets as well as that of the Molina lost call formulas in some KPI while some performs below the expected NCC targets, The overall ranking of operator’s KPI revealed that operator C, operator D, operator B and operator A performed in every category of the key performance index (KPI) in that order
SEDIMENT QUALITY ASSESSMENT OF OKE-ITOKU RIVER, ABEOKUTA, SOUTHWEST NIGERIA
Get PDFThis research investigated contamination of sediments due to continuous tie and dye effluents discharge into Oke-Itoku River, Abeokuta, Nigeria. Surface and subsurface sediment samples were collected upstream, at point of discharge and downstream. The contamination factor (Cf), degree of contamination (Cd) and geo-accumulation index (Igeo) were also determined. Physico-chemical parameters such as Temperature, Total Dissolve Solids (TDS), Electrical Conductivity (EC), pH, Dissolved Oxygen (DO) and five selected heavy metals: Chromium (Cr), Copper (Cu), Cobalt (Co) and Lead (Pb) were measured. Results revealed mean TDS, EC, Temperature and DO pollution of 485.6±134.66 mg/L, 2153.6±1122.19 µS/cm, 32.46±0.570C and 4.01±0.43 mg/L respectively at the discharge point. The heavy metal concentrations for the surface and subsurface sediments obtained had a range of 11.5-18.3, 30.1-39 mg/L for Cr; 12.6-27.0, 23.8-42 mg/L for Cu; 16.2-31.0, 23.8-42.0 for Co and 1.8-3.2, 1.8-3.5 mg/L for Pb in surface and subsurface sediment respectively. Heavy metal contamination in the sediments of Oke-Itoku river showed order of enrichment of Co>Cu>Cr>Pb according to Cf, Cd and Igeo for the study area. There are only natural inputs of chromium and copper into the river while Cd, Co and Pb concentrations are due to anthropogenic input mainly from tie and dye by-products
SUITABLE PARTNER SELECTION IN A DECENTRALISED COOPERATIVE COMMUNICATION VIA THE BUYER-SELLER GAME
Get PDFThe performance and efficiency of a cooperative diversity scheme depend, largely on proper allocation of resources like power and bandwidth. Another important factor to consider is the selection of a proper partner by the source node to help in forwarding information to the destination. In this letter, we look at the concept of relay selection for a distributed communication networks, rather than the more common centralized system where precise channel state information data has to be available at the base station. Also coded cooperation is used as the cooperative scheme rather than the more common amplify-and-forward or decode-and-forward system. A type of game known as non-cooperative game is employed in this analysis so as to jointly consider the utilities of the source and relay nodes, where in this case, the source is the buyer while the relay is the seller. The approach enables the source to maximize its benefit (or utility) by selecting to buy power from the relay that would enable it do so. Results show that at a low price, the source node buys more power from the relay, which also increases the utility of the relay itself. It also shows that among a set of relays competing for the attention of a source node, the source will only select a partner (relay) that gives it the highest utility in terms of the resource, i.e power. In this paper, partner and relay are used interchangeably
EVALUATION OF SUITABLE PROPAGATION MODEL FOR 4G LTE COMMUNICATION IN NIGERIA
Get PDFThis paper concerns about the radio propagation models used for the 4th Generation (4G) of cellular networks known as Long Term Evolution (LTE). The radio wave propagation model or path loss model plays a very significant role in planning of any wireless communication systems. In this paper, a comparison is made between different proposed radio propagation models that would be used for LTE, like Egli model, Ecc-33 path loss model, Log- Normal Shadowing model, Lee model, Stanford University Interim (SUI) model, Cost 231 Hata Model and Experimental Measured path loss. The comparison is made using different terrains such as urban (Victoria Island, Lagos, Nigeria) and suburban (Kurudu, F.c.t. Nigeria). Egli model shows the lowest path loss in all the terrains while illustrates highest path loss in the urban area and model has highest path loss for the suburban environments.