Multivariate and Confirmatory Factor Analysis of Vehicular Emissions in Some Parts of Benin City, Nigeria

Decline in air quality over the years has been linked to the growing rate of urbanization as well as an increase in the number of vehicles occasioned by the increased purchasing power of the people. Most of the pollutants emitted from vehicular activities have been observed to have adverse effects on individuals as well as the atmosphere. The focus of this study is to employ multivariate and confirmatory factor analysis (CFA) based on maximum likelihood estimation, to study the incidence of vehicular emissions in some parts of Benin city metropolis. Seven (7) georeferenced points (University of Benin 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 emission, namely; dinitrogen oxide (NO2), carbon monoxide (CO) including the total radiation were monitored in the morning and evening for a period (7th July to 12th August, 2020) with the aid of portable toxic gas monitors and radiation alert meters. Other measured parameters of interest include maximum temperature and wind speed. To ascertain the quality of the data, selected preliminary analysis, namely; test of normality, test of homogeneity, outlier detection and reliability test were done. With a calculated partial Eta squared based on Pillai’s trace of 0.325, it was concluded that; there exist about 32.50 % variability among the dependent variables. Based on the CFA results, it was concluded that the hypothesis formulated for multivariate analysis of variance fits the sample data. Therefore, the alternate hypothesis was rejected and it was concluded that; the difference in the concentration of vehicular emission was as a result of change in temperature occasioned by time of measurement.

Optimization of the Tungsten Inert Gas Process Parameters using Response Surface Methodology

Optimization is a very important techniques applied in the manufacturing industry that utilizes mathematical and artificial intelligence methods. The complexity associated with most optimization techniques have resulted to search for new ones. This search has led to the emergence of response surface methodology (RSM). The paper aims to optimize tungsten inert gas process parameters required to eliminate post-weld crack formation and stabilize heat input in mild steel weldment using RSM. The main input variables considered are voltage, current and speed whereas the response parameter is Brinell hardness number (BHN). The statistical design of experiment was done using the central composite design technique. The experiment was implemented 20 times with 5 specimens per experiment. The responses were measured, recorded and optimized using RSM. From the results, it was observed that a voltage of 21.95 V, current of 190.0 A, and welding speed of 5.00 mm/s produced a weld material with the following optimal properties; BHN (200.959 HAZ), heat input (1.69076 kJ/mm), cooling rate (72.07 /s), preheat temperature (150.68 ) and amount of diffusible hydrogen (12.36 mL/100g). The optimal solution was selected by design expert with a desirability value of 95.40 %.

Thermodynamic Studies on the Sorption of Lead (II), Chromium (III) and Manganese (II) ions onto Acid-Activated Shale

Shale mineral in its raw form was collected, processed, calcinated and activated using tetraoxosulphate (VI) acid. The microstructural arrangement and chemical composition of the raw, calcinated and acid-activated shale was determined using x-ray fluorescence and scanning electron microscope to verify its ability for the removal of Pb2+, Cr3+ and Mn2+ from wastewater. Batch experimental method was used to study the effect of different adsorption parameters on the sorption efficiency of shale. The effect of temperature on the sorption of Pb2+, Cr3+ and Mn2+ on acid-activated shale was investigated at varied temperature of 15 – 40 . The calculated value of enthalpy () was 12.50 kJ/mol for Pb2+ adsorption, 5 kJ/mol for Cr3+ and 11 kJ/mol for Mn2+ adsorption. The calculated values of Gibbs free energy () varies from -6.576 kJ/mol to 1.358 kJ/mol for Pb2+ adsorptions, from -2.696 kJ/mol to 0.192 kJ/mol for Cr3+ adsorptions, and -4.994 kJ/mol to 1.870 kJ/mol for Mn2+ adsorptions. The entropy () range is 38.68 – 60.946 kJ/mol for Pb2+ adsorptions, 16.69 – 24.58 kJ/mol for Cr3+ adsorptions, and 31.70 – 51.10 kJ/mol for Mn2+ adsorptions. The positive value of shows that the adsorption of Pb2+, Cr3+ and Mn2+ onto acid-activated shale was an endothermic process. The values of are negative at temperature of 298 K and above for the three metal ions studied, which confirmed that the adsorption of Pb2+, Cr3+ and Mn2+ on acid-activated shale was a spontaneous process. The decline in with increasing adsorption temperature showed that adsorptions of Pb2+, Cr3+ and Mn2+ onto acid-activated shale became better at higher temperature while the positive value of for all metal ions studied showed the amplified arbitrariness at the solid-solution interface during the fixation of the adsorbate on the active site of acid-activated shale.

Impacts of Ambient Temperature Change on the Breakdown Voltage of a Distribution Transformer

The aim of this paper is to determine the effects of ambient temperature variation on the breakdown voltage of a distribution transformer. Three different insulation oil samples (naphtha mineral, paraffin mineral and silicon base transformer oil) were collected from six distribution transformers (300 – 500 kVA) across two business units (Asaba and Ugbowo) of Benin Electricity Distribution Company during May and June, 2017. The oil samples were analysed using the 60 kV Megger OST60PB portable oil tester, to determine the trend of breakdown voltage of the oil insulation under varying temperature. A 3rd order polynomial model was deduced for each sample type with coefficient of determination within the range of 96.99 – 99.95 %. The observed average breakdown voltage is 43.6 kV (for naphtha base mineral transformer oil), 42.2 kV (for paraffin base mineral transformer oil) and 46.8 kV (for silicon base transformer oil) within the temperature range (26˚C – 32˚C). The result indicates that the breakdown voltages of the considered transformer oil types are satisfactory but the silicon base transformer oil has the best breakdown voltage.

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

The 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

Determination 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.

Economic Analysis of Cassava Production: Prospects and Challenges in Irepodun Local Government Area, Kwara State, Nigeria

This study was carried out to analyse cassava production, prospects and challenges in Irepodun local government area, Kwara State, Nigeria. It aimed to examine the determinant variables and determine the profitability level of cassava enterprises. The study was based on primary data obtained with the aid of structured questionnaire from 100 cassava farmers drawn through multi-stage sampling techniques from the study area. Data were analysed using descriptive statistics, ordinary least square (OLS) regression model and gross margin analysis. The result of the OLS regression estimates showed that farm size, cost of fertilizer application, farm size, herbicides, family and hired labour were significant variable affecting cassava production in the study area. Fertilizer, farm size and hired labour are significant at 1% while herbicide and family labour are significant at 10%. The study found that the average gross margin per hectare for cassava production in the study area was ₦24,749.28 ($65.30) with a gross benefit ratio of 1.38. This shows that for every ₦1 invested in the business of cassava production, there is a corresponding profit of ₦1.38. The major challenges identified in cassava enterprise are huge transportation cost, high cost of production, lack of improved cassava cultivars, and lack of market linkages. The study concluded despite the problem encountered in the study area, cassava production is profitable and can serve as a panacea for economic improvement of households. Therefore, the study recommends that basic inputs such as improved cassava varieties, herbicides and fertilizer should be made available at affordable price. Also, infrastructural facilities such as good road network and improve marketing channels should be provided in order to sustain current cassava production rate and economic gains from the production.

Determinants of an Effective Solid Wastes Collection at the Workplace: the Experience of the Council for Scientific and Industrial Research-Institute of Industrial Research, Accra, Ghana

The inefficient collection of solid wastes is a global phenomenon that has received attention in recent years for the ever-increasing annual waste generation records. However, indicators to the effective application of the amassing routs are missing. Hence, the generally accepted source-sorting model was explored to identify the determinants that will enhance source separation of wastes at the workplace. This paper presents a foremost report on the indicators to an effective operation of solid wastes source segregation. A quantitatively examined data was collected in sixty-six working days during a monitoring and evaluation process of twenty sets of twin-dustbins that were located at the study area. The generated solid wastes were commonly sorted (65%) in comparison with the mixed collection. Most of the wastes were separated on the third month (80%) of education compared to the first (54%) and second months (61%). Wednesday displayed the working day with the utmost sorted wastes (73%) compared to the other days. All dustbins recorded impressive sorting at the different locations in the Institute. A little over one thousand Ghana cedis savings was made in the first year. Tested null hypothesis showed that, duration and timing of continuous education were significant determinants of the efficient source segregation, relative to the dustbin locations. Therefore, the daily education of waste generators on how to separate wastes at source and the economic benefits will enhance source separation irrespective of the location.