oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 88 )

2018 ( 519 )

2017 ( 449 )

2016 ( 637 )

Custom range...

Search Results: 1 - 10 of 262815 matches for " E. O. Oladiran "
All listed articles are free for downloading (OA Articles)
Page 1 /262815
Display every page Item
The Influence of Atmospheric Parameters on Production and Distribution of Air Pollutants in Bayelsa: A State in the Niger Delta Region of Nigeria  [PDF]
E. I. Njoku, O. E. Ogunsola, E. O. Oladiran
Atmospheric and Climate Sciences (ACS) , 2019, DOI: 10.4236/acs.2019.91011
Abstract: Air pollution is a primary environmental problem in the Niger Delta region of Nigeria due to oil spills including the gas emissions associated with industrial effluents. However, a good understanding and quantification of atmospheric parameters (wind speed, wind direction, temperature, relative humidity, solar radiation and cloud cover) that influence air pollution (CH4, NO2 and O3) concentrations in this region could assist in the mitigation and distribution of these pollutants. This work examines the influence of atmospheric parameters on the production and distribution of air pollutants in the Niger Delta region of Nigeria for the development of control strategies that will enhance the mitigation and amelioration of the significant impacts that these atmospheric pollutants could have on the populace in this part of the country. The CH4 and NO2 data utilized in this study were sourced from the European Space Agency (ESA), while that of tropospheric ozone (O3) was obtained from the National Aeronautics and Space Administration (NASA), and the atmospheric parameters data were provided by the Nigeria Meteorological Agencies (NIMET), Lagos. The analysis of the daily pollutants (CH4, NO2 and O3) including the atmospheric parameters in this region of the Niger Delta for the period 2003 to 2010 was carried out using standard statistical approach including the graphical method, stepwise regression model, least-square method, and correlation analysis. The Mann-Kendal rank statistics was also utilized in identifying the meaningful long-term trends, validation and testing of the homogeneity of the concentrations of the pollutants. The results of the correlations of CH4, NO2 and O3 concentrations with their previous day’s concentrations showed a strong significance in regression analysis for both CH4 and O3. The coefficient of determination of CH4 and O3 was obtained as 0.654 and 0.810 respectively, while a very weak correlation was obtained for NO2. However, despite that a very strong negative correlation of -0.809 and -0.900 was obtained between wind speed and both the CH4 and O3 pollutants respectively, a moderate correlation was obtained between the wind speed and NO2. This implies that amongst the atmospheric parameters considered in this study for the region of the Niger Delta in Nigeria, wind speed has much influence on the
Comparison of Return Stroke Current Profiles for Transmission-Line-Type and Traveling-Current-Source-Type Models
J.O. Adepitan,E.O. Oladiran
Research Journal of Environmental and Earth Sciences , 2012,
Abstract: The study is aimed at determining the dependence of the current along a channel on the model used, assuming the same base current. We compared three transmission-line-type models, namely: Transmission Line (TL), Modified Transmission Line with Linear decay, Modified Transmission Line with Exponential decay and two traveling-current-source-type models: Bruce-Golde (BG) and Traveling Current Source (TCS) models. The current profiles along the channel at different heights predicted by these models are presented and discussed. Comparison is based on the assumption that all the models have the same base current. It was found that at low heights and within a time window frame of 15 :s, the currents of the transmission-line-type models predict a zero value at one time or the other with a maximum turning point following some 1:s after. A linear relationship is predicted between the current peak and the channel height. A discontinuity of current peak was observed at high heights. No zero value of current was recorded in case of TCS both at low and high channel heights.
Analysis of the Dependence of Power Outages on Lightning Events within the Ijebu Province, Nigeria
J.O. Adepitan,E.O.Oladiran
Research Journal of Environmental and Earth Sciences , 2012,
Abstract: The study aimed at developing a model for lightning-induced outages in Nigeria from results obtained on determining the proportion and rate of lightning-induced outages out of the total power outages experienced in Ijebu province of Nigeria. Power outage records for Ijebu province, comprising Ijebu-Ode and Sagamu areas, Ogun state, Nigeria for the years 2002-2006 were collected from Power Holding Company of Nigeria (PHCN). Unintentional stochastic outages were separated from those due to deliberate load shedding. Lightning events records were collected from Nigeria Meteorological Agency for the same period. The two sets of time series were superimposed. Outages with time, t<1 min after lightning events were classified as ‘Lightning-Induced’ (LI). Those with 1≤t≤6 min were classified as ‘Possibly Lightning-Induced’ (PLI) while those with t>6 min were classified as ‘Others’ (OT). The two sets of data were analyzed in order to determine percentage of lightning-induced outagfes. Also, thunderstorm days and power line parameters were used as input data for modified FLASH 1.7 software (considering tropical region) to estimate the rate of lightning induced outages. The five-year period, 2002 to 2006, experienced no significant difference (p<0.05) in the mean of percentage of LI outages for both areas, calculated as 8.6 for Ijebu-Ode and 9.5 for Sagamu. The corresponding values for PLI being 1 and 2%; whereas OT had values 90.4 and 88.5%. Where earth wires were available on the transmission lines, the mafn lightning-induced outage rate was 1/100 km-year. The mean flashover rate for unshielded lines was 22/100 km-year. A linear relationship was established between the annual lightning-induced outages and the annual lightning days for the province. Lightning accounted for approximately 10% of the random outages experienced in Ijebu province. Lightning-induced outages are linearly related to lightning days. Lightning-induced outage rate is much higher over unshielded than shielded transmission lines.
Temporal and Spatial Variability of Ozone Concentration over Four African Stations
M.L. Akinyemi,E.O. Oladiran
Journal of Applied Sciences , 2007,
Abstract: The temporal and spatial variability of ozone at four different locations over Africa were studied using satellite data from 1997 to 2002. The stations were Lagos and Dakar in the northern tropics, Kinshasa and Nampula in the southern tropics. The analysis revealed both high and low frequency time component. The temporal variation of ozone was of the high frequency component, while the seasonal oscillations were either annual or biannual. Annual seasonal oscillations were observed at Lagos and Dakar with oscillation period varying between 295 and 375 days, while biannual seasonal oscillations were observed at Kinshasa and Nampula with oscillation period varying between 120 and 200 days. Ozone temporal oscillation periods in all the four locations were between 2 and 6 days. The temporal amplitude varied between 1.0 and 6.5 DU. The observation of the effect of the Quassi Biennial Oscillation (QBO) was more prominent at Lagos than the other three stations. In the years of QBO occurrences, the annual mean of ozone concentration at Lagos were higher than those of Dakar by an average value of 10 DU. While the difference in the years of non-QBO were marginal with an average value of ±1.4 DU. Seasonal and annual variations of ozone concentration over the tropics had higher correlation with location than the temporal variation. Temporal variation was found to be less dependent on the spatial variation.
Variability and Probabilistic Extremes of Some Climatic Elements over Ibadan
T.A. Otunla,E.O. Oladiran,M.O. Adeniyi
Online Journal of Earth Sciences , 2012,
Abstract: Data on different climatic elements, like monthly rainfall monthly mean relative humidity, monthly lowest relative humidity; monthly mean temperature, monthly mean maximum and minimum temperatures with their monthly extremes values and monthly mean prevailing wind speeds over Ibadan for the months of January through to December during the period of 1979 through to 2005 have been considered to study their variability and to determine the probabilistic extreme values of these elements. The probabilistic extremes values have been computed for 3 time scales: In 1 year out of 4 years, in 1 year out of 10 years and in 1 year out of 25 years-representing relative more frequent events, moderately extreme events and extreme events, respectively.
Biodiesel for Sustainable Energy Provision in Developing Countries  [PDF]
Moses Tunde Oladiran, Jerekias Gandure
Low Carbon Economy (LCE) , 2011, DOI: 10.4236/lce.2011.23017
Abstract: Consumption of fossil fuel resources has been growing over the years and it is the kernel of economic development. However combustion which takes place principally in automobiles, power generation and industrial plants produces greenhouse gases (GHG) that are harmful to the environment. The release of GHG such as carbon dioxide is contributing to global warming. Biofuels can lower carbon footprint, reduce dependence on imported fossil fuels and increase energy security. Integrating biofuels into the national energy mix also has good socio-economic and sustainability potential. Therefore this paper discusses factors for successful diffusion of biodiesel technology in developing economies.
The Use of Greenhouse Gases as Climate Proxy Data in Interpreting Climatic Variability  [PDF]
Oluseyi Enitan Ogunsola, Ezekiel Oluyemi Oladiran
Atmospheric and Climate Sciences (ACS) , 2013, DOI: 10.4236/acs.2013.31002
Abstract:

Greenhouse gas data were utilized as proxy data in interpreting climate variability. These greenhouse gases were related to temperature records using standard deviation (SD) as the transfer function based on observed correlations between them and global warming records. The annual SD used as warming index for the concentrations of these greenhouse gases for the period 1996 to 2005 at the various stations considered showed good correlation with 1998 as the warmest for these stations.

Natural Radionuclide Concentrations and Radiological Impact Assessment of River Sediments of the Coastal Areas of Nigeria  [PDF]
Olatunde Michael Oni, Idowu Peter Farai, Ayodeji Oladiran Awodugba
Journal of Environmental Protection (JEP) , 2011, DOI: 10.4236/jep.2011.24047
Abstract: This work was carried out to measure the radioactivity level in the coastal areas of Nigeria by gamma counting of river sediment samples and assess the radiological impact associated with the use of the river sediments as building material. The method of gamma spectrometry with a 7.6 cm by 7.6 cm NaI(Tl) detector was employed in determining 40K, 238U and 232Th levels in 95 and 38 sediment samples respectively collected from representative sites in the oil producing and non oil producing coastal areas of Nigeria. Results of the samples assayed showed that the radioactivity concentrations of 40K, 226Ra and 228Ra in the sediment samples of oil producing areas range from 95.4 to 160.0; 7.6 to 31.0 and 9.5 to 41.6 Bq kg–1, respectively. The respective means were calculated as 122.39 ± 47.49; 18.93 ± 12.53 and 29.31 ± 18.67 Bq kg–1. In the sediment samples from the non oil producing areas, the respective mean values are 88.48 ± 8.22, 14.87 ± 3.51 and 16.37 ± 3.87 Bq kg–1. Statistical analysis of the results showed that there is no significant difference between the radionuclide concentration of the sediment samples from different rivers in the oil producing and non oil producing coastal areas, except for 40K. The values of the natural radionuclide concentrations however translate to the determina-tion of the radiological impact assessment values. The values of the radiological assessment indices obtained were ob-served to be lower than limits internationally reported and recommended for building materials. It could therefore be reported that the operations of the oil companies in the coastline, involving use of radioactive materials have not contributed adversely to the radioactivity level of the river sediments and that the use of river sediments as building mate-rial in the coastal areas of Nigeria poses no radiological risk.
Community screening and treatment of asymptomatic carriers of Plasmodium falciparum with artemether-lumefantrine to reduce malaria disease burden: a modelling and simulation analysis
Steven E Kern, Alfred B Tiono, Michael Makanga, Adama Gbadoé, Zulfiqarali Premji, Oumar Gaye, Issaka Sagara, David Ubben, Marc Cousin, Fiyinfolu Oladiran, Oliver Sander, Bernhards Ogutu
Malaria Journal , 2011, DOI: 10.1186/1475-2875-10-210
Abstract: Using computer simulation, this analysis explored the impact of community screening campaigns (CSC) followed by systematic treatment of P. falciparum asymptomatic carriers (AC) with artemether-lumefantrine (AL) on disease transmission. The model created by Okell et al (originally designed to explore the impact of the introduction of treatment with artemisinin-based combination therapy on malaria endemicity) was modified to represent CSC and treatment of AC with AL, with the addition of malaria vector seasonality. The age grouping, relative distribution of age in a region, and degree of heterogeneity in disease transmission were maintained. The number and frequency of CSC and their relative timing were explored in terms of their effect on malaria incidence. A sensitivity analysis was conducted to determine the factors with the greatest impact on the model predictions.The simulation showed that the intervention that had the largest effect was performed in an area with high endemicity (entomological inoculation rate, EIR > 200); however, the rate of infection returned to its normal level in the subsequent year, unless the intervention was repeated. In areas with low disease burden (EIR < 10), the reduction was sustained for over three years after a single intervention. Three CSC scheduled in close succession (monthly intervals) at the start of the dry season had the greatest impact on the success of the intervention.Community screening and treatment of asymptomatic carriers with AL may reduce malaria transmission significantly. The initial level of disease intensity has the greatest impact on the potential magnitude and duration of malaria reduction. When combined with other interventions (e.g. long-lasting insecticide-treated nets, rapid diagnostic tests, prompt diagnosis and treatment, and, where appropriate, indoor residual spraying) the effect of this intervention can be sustained for many years, and it could become a tool to accelerate the reduction in transmissio
ASSESSMENT OF PINE BIOMASS DENSITY THROUGH MID-INFRARED SPECTROSCOPY AND MULTIVARIATE MODELING
Brian Via,Oladiran Fasina,Hui Pan
BioResources , 2011,
Abstract: The assessment of wood biomass density through multivariate modeling of mid-infrared spectra can be useful for interpreting the relationship between feedstock density and functional groups. This study looked at predicting feedstock density from mid-infrared spectra and interpreting the multivariate models. The wood samples possessed a random cell wall orientation, which would be typical of wood chips in a feedstock process. Principal component regression and multiple linear regression models were compared both before and after conversion of the raw spectra into the 1st derivative. A principal component regression model from 1st derivative spectra exhibited the best calibration statistics, while a multiple linear regression model from the 1st derivative spectra yielded nearly similar performance. Earlywood and latewood based spectra exhibited significant differences in carbohydrate-associated bands (1000 and 1060 cm-1). Only statistically significant principal component terms (alpha less than 0.05) were chosen for regression; likewise, band assignments only originated from statistically significant principal components. Cellulose, lignin, and hemicelllose associated bands were found to be important in the prediction of wood density.
Page 1 /262815
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.