Browsing by Author "Olawole OC"

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    A GIS – based method for assessment and mapping of noise pollution in Ota metropolis, Nigeria
    (2019) Oyedepo SO; Adeyemi GA; Olawole OC; Ohijeagbon OI; Fagbemi OK; Solomon R; Ongbali SO; Babalola OP; Dirisu JO; Efemwenkiekie UK; Adekeye T; Nwaokocha CN
    A detailed method used for assessing and mapping noise pollution levels in Ota metropolis, Nigeria using ArcGIS 10.5 Software is presented in this paper. Noise readings were measured at a time interval of 30 min for each site considered using a precision grade sound level meter. The noise map developed was based on the computed values of average equivalent noise (LAeq) for the selected locations. Results of this study show that the A weighted sound level (LAeq), the background noise level (L10) and the peak noise level (L90) vary with location and period of the day due to traffic characteristics especially traffic volume, vehicle horns, vehicle mounted speakers, and unmuffled vehicles at road Junctions, major roads, motor parks and commercial centres. Based on the U.S. Department of Housing and Urban Development (HUD) recommendations and standards, only one (1) out of the 41 locations considered is under normally acceptable situation, while 12 locations are under normally unacceptable and the noise levels of the rest locations are clearly unacceptable. Results of this study are useful as reference and guideline for future planning and regulations on noise limit to be implemented for urban areas like Ota Metropolis. •Instrumentation used in this study for the environmental noise measurements consisted of a precision-grade sound-level meter – Model 8922 RS232.•The Geographical Positioning System (GPS) device (model: Magellan eXplorist 310) was used to obtain the exact coordinates of each location where noise level readings were recorded.•ArcGIS 10.5 software was used in this study to develop noise map for Ota Metropolis.
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    Assessment of background radionuclides and gamma dose rate distribution in Urban-setting and its radiological significance
    (2020) Joel ES; De DK; Omeje M; Adewoyin O; Olawole OC; Akinwumi A; Erubami S; Adeyemi GA
    Background Awareness of the dangers associated with exposure to high radiation in the environment is necessary to avoid its health impact, especially when staying in-door. Method Assessment of gamma dose rate and radionuclides in urban settings of Ota has been carried out using a hand-held gamma detector to determine the hotspot of high radionuclides concentration in the study area. In this study, eighteen (18) stations were covered, gamma dose rate and radio-nuclides (Uranium-238, Thorium-232, and Potassium-40) emitting from the subsurface were measured. Results The result showed that the mean value for the measured dose rate of 45.06 nGh−1 is below the suggested value of 84 nGh−1 while the estimated mean values for the radionuclides are were 23.81, 45.35 and 77.82 Bq/kg respectively. The evaluated radium equivalent (Raeq), internal index (Hin), external index (Hex) and gamma index (Iy) ranges from 70.92 to 128.70 Bq/kg, 0.24 to 0.41, 0.19 to 0.35 and 0.25 to 0.46 respectively. Furthermore, the estimated value of the alpha index ranged between 0.05 and 0.15, and an annual effective dose rate from 0.33 to 0.55. The estimated mean value of excess cancer lifetime risk is 0.0015. Conclusions Therefore, the study suggests that the study area is safe for the residents. However, radioactivity concentration emanating from the subsurface of the setting should be monitored to avoid the environmental-health implication of accumulation of low gamma-dose, which can cause cancer of the lung due to anthropogenic activities.
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    Dataset on noise level measurement in Ota metropolis, Nigeria
    (2019) Oyedepo SO; Adeyemi GA; Fayomi OS; Fagbemi OK; Solomon R; Adekeye T; Babalola OP; Akinyemi ML; Olawole OC; Joel ES; Nwanya SC
    Datasets contained in this article are noise level measurement carried out at 41 different locations in Ota metropolis, Nigeria. The noise readings were measured at a time interval of 30 min for each site considered using a precision grade sound level meter. The analysis was based on the noise descriptors LAeq, L10, L90, LD, TNI and NEI. Results from the study reflects that the highest and lowest equivalent noise levels (LAeq) were recorded at commercial areas (96 dB (A)) and residential areas (52 dB (A)), respectively, the background noise level (L90) has the highest and lowest values at commercial areas (77 dB (A)) and residential areas (44 dB (A)), respectively and the peak value (L10) has the highest value and lowest value at the commercial areas (96 dB (A)) and residential areas (56 dB (A)). Based on the WHO recommendations and standards, only 2 out of the 41 locations considered are under normally acceptable situation while the noise levels of other areas are not acceptable. Noise map developed in this study provides enough information for technical controls and interim legislation against environmental noise pollution in the metropolis. Moreover, considering the noise emission standards, planning and promoting the citizens awareness about the high noise risk could help to mitigate the effect of noise in Ota, Metropolis. The noise data in this study are useful as reference and guideline for future regulations on noise limit to be implemented for urban areas in Nigeria and developing countries at large.
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    Geo-investigation on groundwater control in some parts of Ogun state using data from Shuttle Radar Topography Mission and vertical electrical soundings
    (2020) Joel ES; Olasehinde PI; Adagunodo TA; Omeje M; Oha I; Akinyemi ML; Olawole OC
    Groundwater is a vital natural resource that plays a significant function in sustainability of living things on earth. Its exploration requires special skill for optimum exploitation. Shuttle Radar Topography Mission (SRTM)and Vertical Electrical Sounding (VES) were used to detectthe stratigraphy and subsurface structures controlling the groundwater system around Iju – Ota, Ogun State, Southwestern Nigeria. Nineteen (19) VES points were carried out where there were dense concentrations of lineaments and interconnected to establish the connection of the observed lineaments with groundwater occurrence in the study area using Schlumberger array, with electrode spacing of AB/2 varying from 180 to 320 m. The analysis of SRTM data revealedthe dominating structural NE-SW and NW-SE trends, which control aquifer structure. The geoelectrical parameters from the VES results were used to map the stratigraphic sequences in the study area. Six (6) units that comprisethe topsoil, lateritic clay, clayey sand, mudstone, sand (main aquifer), and shale or clay were identified in the study area. The aquiferous unit around Iju – Ota axis ranged from 30 to 80 m. Theextracted from the hill shaded SRTM data and the result of VES revealed that the thickness of the aquifer is as a result of interconnectivity of the lineaments observed in the SRTM data suggesting that the groundwater occurrence in the study area is chiefly controlled by these fractures.
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    Response surface methodology and artificial neural network analysis of crude palm kernel oil biodiesel production
    (2020) Ayoola AA; Hymore FK; Omonhinmin CA; Babalola PO; Fayomi OS; Olawole OC; Olawepo AV; Babalola A
    Response surface methodology (RSM) and Artificial neural network (ANN) analysis of crude palm kernel oil (CPKO) biodiesel production, using KOH and NaOH catalysts, were carried out in this research work. The four process parameters considered during the production process and modelling stages were 6–12 mol ratio of methanol/oil, 0.7–1.7 wt/wt% catalyst concentration, 48–62 °C reaction temperature and 50–90 min reaction time. Log sigmoid function and Levenberg marquardt technique were adopted in ANN while Box-Benkhen method was utilised for RSM. The results revealed that KOH catalyst process produced higher yield of biodiesel (87 – 99%), compared to the yield obtained from NaOH catalysed process (79 – 91%). The regression coefficients for RSM models were 0.9324 for KOH catalysed process and 0.8935 for NaOH catalysed process, while the overall correlation coefficients for ANN models were 0.82921 for KOH catalysed process and 0.89396 for NaOH catalysed process, an implication that RSM is a better analytical tool (compare to ANN) in models formulation.