Browsing by Author "James, U. E."

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Environmental assessment of radionuclide exposure in packaged borehole water exploited from crystalline rocks in Ogbomoso
(ICSAEES-2024, Lagos, Nigeria, 2024) Oladipo, A. E.; Aremu, A. A.; Adeniji, A. A.; Ayinla, T. O.; Babarimisa, I. O.; Morakinyo, R. O.; Araka, I. O.; James, U. E.
The amounts of naturally occurring radionuclides (40K, 238U and 232Th) in packaged borehole water manufacture have been investigated in this work. Furthermore, the buildup of radioactive materials in drinking water presents a direct path for human population exposure to internal radiation. The amount of radioactivity in the processed and unprocessed water samples was measured using gamma spectrometry and a computer-resident quantum multichannel analyser (MCA 2100R) connected to a well-calibrated and shielded NaI (Tl) detector. From the results, it was revealed that the values of activity concentration of processed water ranges between 50.46 ± 3.14 Bq/L to 102.18 ± 14.07 Bq/L, 7.92 ± 4.46 to 16.71 Bq/L, and 10.00 ± 0.84 Bq/L to 14.87 ± 4.03 Bq/L for 40K, 238U and 232Th, respectively. Also, the results obtained for the activity concentration of unprocessed water ranges between 74.51 ± 3.51 Bq/L to 102.21 ± 7.23 Bq/L, 14.86 ± 1.91 Bq/L to 19.87 ± 3.10 Bq/L and 10.00 ± 3.36 Bq/L to 17.79 ± 4.43 Bq/L for 40K, 238U and 232Th, respectively. The results confirmed the presence of40K as a principal occurring radionuclide in the water samples. The annual effective dose for processed water ranges from 0.012 to 0.017 mSyr-1, while it ranges between 0.015 and 0.020 mSyr-1 for unprocessed water. Results in the present study fall below 0.1 mSyr-1, which is the acceptable limit recommended by International Commission on Radiological Protection standard value.
Environmental Impact of Pre-occupational radon level measurements in medical imaging facilities of a tertiary hospital in south-west Nigeria
(ICSAEES-2024, Lagos, Nigeria, 2024) Aremu, A. A.; Oni, O. M.; Oladipo, A. E.; Oladapo, O. O.; Obafemi, Y. D.; Oniha, M. I.; Babarimisa, I. O.; James, U. E.
Radiation facilities are placed in an enclosed environment to prevent scattered radiation from getting out of the room, by so doing the rooms foil gas exchange from the outdoor environment, thereby increasing the radon concentration in the indoor air. This study aimed at estimating the occupational radon exposure level in medical facility room in order to estimate the radiological risk in such environment. RAD7 electronic device was used to measure theindoor radon concentration in the five proposed roomsin the newly built Radiology department of a University Teaching Hospital while a digital thermometer was used to measure the ambient temperature. The radon concentrations ranged between 12.09Bq/m3and 58.52 Bq/m3. The ultrasound room has the least average value of 12.09 Bqm-3 and the Fluoroscopy room has the maximum average value of 58.52 Bqm-3. The radon level translated into the effective dose, working level and excess life-time cancer risk for any worker staying for a period of nine hours per day, over a year. Fluoroscopy facility was estimated to present the highest annual absorbed dose and annual effective dose with 0.73 mSvy-1 and 0.8858 mSv y-1, respectively.The mean radon concentration for the five rooms was 41.96Bq/m3. The calculated annual effective dose rate and the mean annual absorbed dose rate to the lung within the radiation facilities rooms were 0.529 mSvy- 1and 0.6350 mSv y-1, respectively.The indoor radon concentrations measured and the effective dose value of 200 Bq/m3 and 1 mSvy-1 respectively is below the reference limitset by International Commission Radiation Protection (ICRP) Agency.This implies that the radiation facility rooms are in conformity with international best practices and this is in agreement with SDG 3 (Good Health and well –being)
Theoretical Study of Quantum Efficiency and Spectral Response of Solar Cells
(7th International Conference on Science and Sustainable Development and Workshop, 2024) James, U. E.; Dim, C. C.; Akinyemi, M. L.; Ogunrinola, I. E.
A theoretical study of Quantum Efficiency (QE) and Spectral Response (SR) of solar cells was done in order to suggest ways in which related parameters could be optimized for maximum conversion efficiency of solar cells. Secondary data for the base, emitter and total parameters of QE and SR were obtained. MATLAB was employed in plotting and analysing these data across different diffusion lengths. From the results obtained, it was observed that when the value of the Emitter Diffusion Length (EDL) was varied from 0.3µm to 0.5µm, the emitter and total values of QE increased by about 700% at wavelength 300nm – 400nm. In the case of SR, it was observed that when there was an increase in the Base Diffusion Length (BDL) from 20µm to 50µm, there was an increase of about 26% at wavelength 800nm – 900nm. A rise in the diffusion length was seen to increase both the QE and SR of the cell. Thus, it can be suggested that an increase in the emitter and base diffusion length of a solar cell leads to a decrease in the recombination charges in the cell, giving more time for the charge carriers to exit the cell.