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Emission dispersion modeling and geospatial analysis of vehicular emissions in some parts of Benin City, Nigeria
Get PDFOver the years, decline in air quality has been connected to the growing rate of urbanization and increasing number of vehicles on the roads. Most of the pollutants emitted from vehicular activities have been observed to have adverse effects on individuals as well as the atmosphere. Although, the focus of this study is to develop an emission dispersion model to predict the concentration of specific air pollutants with distance, the application of geostatistical technique such as Kriging interpolation to study the spatial distribution of pollutants from vehicular emissions around the study area was also exemplified. Seven (7) georeferenced points, namely, Ugbowo main gate, Ekosodin junction, Agen junction, Super D junction, Nitel junction, Okhunmwun junction and Oluku market junction were used for data collection. Pollutants from vehicular emissions, namely, nitrogen dioxide (NO2), carbon monoxide (CO) including the total radiation were monitored in the morning and evening for a period of 35 days (7th July to 12th August 2020) with the aid of portable toxic gas monitors and radiation alert meters. Other parameters of interest, which were also measured include maximum temperature and wind speed using infra-red thermometers and portable anemometer respectively. To ascertain the quality of the data, selected preliminary analysis, namely, test of normality, test of homogeneity, outlier detection and reliability test were done. Result of the study showed a high concentration of NO2, CO and total radiation around Ugbowo main gate and Okhunmwun community and environs especially during the peak hours of evening (5.0 p.m. – 6.0 p.m.) when the traffic load is high
Estimated billing system is the bane of grid electric power supply and development in Nigeria: An empirical analysis
Get PDFThe estimated billing system for electricity was introduced in Nigeria by the Nigerian Electricity Regulatory Commission (NERC) in 2012 for billing customers without meters or with faulty or inaccessible meters. But instead of following the guidelines and formula provided by NERC for the estimation, the electricity Distribution Companies (DisCos) resorted to billing these customers arbitrarily and frustrated efforts by NERC to ensure the proper metering of electricity consumers. This research evaluates the incentive, which makes the DisCos in Nigeria prefer the estimating billing system to a much more efficient smart prepaid metering system. To carry out the research, four Enugu Electricity Distribution Company (EEDC) customers were selected. The estimated bills of these customers, which they received before they got smart prepaid meters, were compared with their prepaid meter bills for an equal period. EEDC was found to be over-billing these customers under the estimated billing system by a yearly average per customer of 64,901.67 Nigerian Naira (170.79 USD)
Numerical analysis of steel columns subject to eccentric loadings
Get PDFBuckling of framed and plated structures has been a great concern that researchers try to handle over the past decades. In most developing nations such as ours, fewer or no experimental trials are available to obtain requisite information for the proper understanding of this phenomenon. It is on this premise that an attempt is made to conduct a preliminary study to numerically evaluate the buckling of steel columns under eccentric loadings. To achieve this, a static, linear perturbation analysis was initially performed on a pin-ended steel column using the subspace Eigen solver for the different buckled mode shapes to illustrate the likely behaviour of the column when subjected to compressive actions. Then, the static, general analysis was conducted with the column subjected to varying magnitudes of eccentric loadings. It was required to determine the load level at which the column would fail when subjected to these eccentric loadings. Consequently, a base load value equivalent to 10 % of Euler's critical buckling load was used. This load value was thereafter increased by 20 % in sequence. It was discovered that 10 % of the Euler's critical buckling load can alter the stiffness of the column when loaded eccentrically. It was further observed that the steel column finally failed at a load greater than 20 % of the Euler's critical buckling load and 40.1% of Rankine's critical buckling load. This is because the permissible deflection for unbraced columns may be taken as the quotient of effective length of column to 250, which translates to 13.8 mm. Therefore, the maximum deflection of 14.72 mm reached by applying an eccentric load of 514 kN exceeds the allowable limit of 13.8 mm
Investigation of the spatial variation of sediments heavy metals along the Nun River using kriging interpolation technique
Get PDFThis study employs geospatial statistical technique to assess the spatial distribution of heavy metals along the Nun River. Core sediment samples were collected from relatively undisturbed areas (twenty-five different stations) using Uwitec Triple sediment cutter. The rectangular coordinates of the sediment sample location were determined with the aid of Germin handheld GPS receiver. The concentrations of cadmium, lead chromium and zinc present in the sediments was determined with the aid of an atomic absorption spectrophotometer. For geospatial analysis, five semi-variogram models (stable, circular, spherical, exponential and K-Bessel) were fitted for each of the four critical parameters (heavy metals). In addition, four goodness-of-fit statistics (mean square error, root mean square error, root mean square standardized error and average standard error) were utilized to decide the most suitable model used to develop the final prediction map for each parameter. From the results obtained, it was observed that; regions with red color codes signify higher concentrations of cadmium, lead, chromium and zinc. Further assessment of the results showed that Otuan, Obeleli, Angiama, Odobio, Kasama, Akedda and Akele experienced high concentration of cadmium while Tombia, Ewoi, Abilabio, Agudama and Yenikpa experienced high concentration of lead
Development of an RFID-based security door system
Get PDFThis paper describes the development of a two-factor radio frequency identification (RFID)-based security door authentication scheme that can provide efficient control facilities to restrict the entry of an unauthorised door user. The developed system consists of the RFID unit, a microcontroller programmed to control the operation of the door using a synchronous motor. The multiplexers that comprise integrated circuits combined with the liquid crystal display was utilized for displaying the status of the card user while the alarm system informs the public of an intruder. The experimental results are presented and discussed
Reliability optimization on power systems network using genetic algorithm
Get PDFIn this study, reliability optimization of a non-linear transmission network using Genetic Algorithm (GA) based optimization approach is presented and proposed. A GA based algorithm was developed for Koko, Guinness, Nekpenekpen, Ikpoba-Dam, Switch station, Etete and GRA 33kV tertiary transmission feeders within Benin Metropolis, Nigeria and was used to determine the optimal performance of the feeders’ reliability and availability through the minimization of downtime and the Mean Time between Failure (MTBF) by the appropriate selection of the objective functions and constraints. The equality and inequality constraints for each feeder on the network were defined, thereafter, codes were written on the Matlab 2016a environment to optimize the selected parameters. The results from the study showed a reduction in downtime of 5.63%, 26.87%, 34.20%, 5.42% 8.37%, 5.18% and 10.97% and an increment increased in MTBF by 4.95%, 19.87%, 4.58%, 3.85%, 4.88%, 5.77% and 13.56% for Guinness, Etete, Nekpenekpen, GRA, Switch station and Ikpoba-Dam feeders respectively. The obtained results, therefore, yielded an average corresponding improvement on the network’s reliability and availability by 1.85% and 2.83% respectively. Conclusively, the desired result reached in this paper validates the robustness of the GA tool in reliability studies. However, conscious effort must be geared concerning the ways and manners the system is operated in order to achieve desired results
Extraction of the pulse width and pulse repetition period of linear FM radar signal using time-frequency analysis
Get PDFA common technique used by military to realize low probability of intercept (LPI) is linear frequency modulation (LFM) in the field of electronic intelligence (ELINT). This paper estimates the pulse width (PW) and the pulse repetition period (PRP) of LFM signal using instantaneous powers. The instantaneous powers were obtained either using time-marginal or power maxima approximated from a modified version of the Wigner-Ville distribution (WVD). The instantaneous power was also gotten directly from the signal by multiplication with its conjugate. Measurement was then carried out when the instantaneous power is ‘ON’ (the PW) and when it is ‘OFF’ (the PRP) at carefully selected thresholds. Thereafter, the mWVD-based algorithm was tested in the presence of additive white Gaussian noise (AWGN) at various signal-to-noise ratios. Results obtained during the test showed that the time marginal method emerged the best with minimum signal-to-noise ratio (SNR) of -5dB followed closely by the direct method with minimum SNR of -1dB at different thresholds. The results show that the proposed algorithm based on this modified WVD can be deployed in the practical field to determine radar’s performance and functio
Comparative studies of surfactant-enhanced-water, WAG and surfactant-enhanced-WAG injections in concurrent development of thin oil rim reservoir
Get PDFThe goal of this paper is the comparative analysis of three injection fluid options: Surfactant-enhanced-Water (SeW), Water Alternating Gas (WAG) and Surfactant-enhanced-WAG (SeWAG). The objectives are to identify the best option with the highest oil and gas displacement efficiency and the best development strategy for optimum recoveries in concurrent development of an oil rim reservoir. The Eclipse simulator was used because of its robust ability in simulating various injection options of an oil rim reservoir in a green field. Four scenarios (base case/no injection, SeW, WAG and SeWAG injections) were simulated under the same conditions to determine injection option with the best displacement efficiency and recoveries of oil and gas. Statistical analysis using Pareto chart was performed for proper identification of the option with the best recoveries. The result showed that SeWAG injection ratio 1:4:2 and injection cycles 56 gave the best recoveries for oil and gas with displacement efficiency of 0.08 and 0.332 respectively, followed by SeW injection with values of 0.073 and 0.331 respectively, while WAG has the least performance. On the Pareto chart, SeWAG simulation result has the highest percentage among the options with the best recoveries of 3.35 MMSTB oil and 16.05 BSCF gas, which is 12.53% and 16.12% of oil and gas in place after 9.6% of oil and 15.1% of gas have been recovered by natural depletion. Hence, this study has shown that two stages of development strategy (combination of natural depletion and SeWAG injection when the reservoir pressure is depleted) give cumulative effect for optimal recoveries in concurrent development of oil rim reservoir
Attempt on Magnification of the Mechanism of Enzyme Catalyzed Reaction through Bio-geometric Model for the Five Points Circle in the Triangular Form of Lineweaver-Burk Plot
Get PDFThe bio-geometrical model is dealing with correlation between the “five events for enzyme catalyzed reaction” and “triple point event serving groups on the circle” in triangle obtained for the graphical presentation of the double reciprocal for magnification of the mechanism of enzyme catalyzed reaction. This model is based on the nine point circle in triangle of the double reciprocal plot. The five significant points (B, D, E, F and G) resulted for the circle with x – and y – coordinates. The present attempt is considering interactions among enzymes and substrates for the successful release of product through each and every point on the circle in triangle. The controlling role of the point, “O”, center of circle in each and every event of the biochemical reaction is obligatory. The model is allotting specific role for the significant events in the biochemical reaction catalyzed by the enzymes. The enzymatic catalysis is supposed to be completed through five events, which may be named as, “Bio-geometrical events of enzyme catalyzed reaction”. These five events for enzyme catalyzed reaction include: (1) Initial event of enzymatic interaction with the substrates; (2) Event of the first transition state for the formation of “enzyme-substrate” complex; (3) Event of the second transition state for the formation of “enzyme-product” complex; (4) Event of release of the product and relieve enzyme and (5) The event of directing the enzyme to continue the reaction. The model utilizes the “triple point serving group on the circle” for the success of each and every event in the biochemical reaction. Thus, there is involvement of the three points including the point “O” for each event in the enzyme catalyzed reaction. The group of points serving for carrying out the event may be classified into five conic sections like: B-O-E; E-O-G; G-O-D; D-O-F and F-O-B. The bio-geometrical model is correlation between the “five events for enzyme catalyzed reaction” and “triple point event serving groups on the circle” in a triangle of the double reciprocal plot
Analysis of Annual Maximum Rainfall Series using Method of L-Moments in Some Selected Sites in South-South Geographical Zone, Nigeria
Get PDFDetermination of the extent of peak rainfall for different return periods is an essential ingredient for the accurate design of hydraulic structures such as drains, dams and culverts as well as detection of flood risk areas. The focus of this study is to analyze annual maximum daily rainfall series in some selected sites within the coastal region of Nigeria using three parameter probability distribution models, namely, Generalized Logistics (GLO), Generalized Extreme Value (GEV) and Generalized Pareto (GPA) with the view of identifying the best fit probability distribution model per station that can be employed to estimate the rainfall magnitude for selected return periods. Specific time series analysis test, namely, detection of outlier and homogeneity test were performed to certify that the data utilized are adequate and suitable. Descriptive statistics such as sample mean, variance, standard deviation, kurtosis, skewness, and coefficient of variation were computed using basic statistical equations. The probability weighted moment parameters (b0, b1, b2 and b3), L-moment values (λ1, λ2, λ3 and λ4) and ratios (τ2, τ 3 and τ4) including the distribution parameters, namely, shape (k), scale (α) and location (ξ) parameters were computed based on L-moments procedures. To select the best-fit probability distribution model per station, carefully chosen goodness-of-fit statistics, namely, root mean square error, relative root mean square error, maximum absolute deviation index, maximum absolute error and probability plot correlation coefficient were employed since they can adequately assess the fitted distribution at a site. Results obtained indicate that the GLO is the best fit distribution for analyzing annual maximum daily rainfall series from Warri and Calabar while GPA for Port Harcourt and Uyo