Measurement and Analyses of indoor radon level at a University in South-Eastern Nigeria (Published)
Lung cancer has been linked to exposure to the naturally occurring ionizing radiation, radon gas (22Rn). Radon is ubiquitous in our environment. However, the level of concentration of this gas is influenced by the geological, geographical, meteorological conditions of a particular environment. The indoor radon concentration is also influenced by factors such as air-conditioning system, ventilation, age of building etc. In this study, the level of indoor radon was measured in 55 offices located within Abia State University, Uturu in South Eastern Nigeria using a Corentium digital radon detector. Uturu is well known for vegetation with high granitic and sedimentary rocks. Offices were chosen to vary between those that are furnished with air conditioning systems and those that are without such facility. Measurements were taken between December 2017 to June 2018. The result of the measurements showed that the indoor radon concentration for all the offices varied between. This value is lower than the intervention level of recommended by International Commission on Radiological Protection (ICRP). The annual effective dose for the offices ranged from which is below the recommended ICRP intervention level of. Hence, there is low risk of adverse health effect and lung cancer induction to the staff of Abia State University.
Keywords: Effective dose, Nigeria, exposure, indoor radon, lung cancer
Lighting Discharge on Power Lines- Case Study of Afam Power Plant, Nigeria (Published)
This study reports on the effects of lightning discharge on power lines in Afam Power Plant, Nigeria. Unstable electrical power transmission is one of the myriads of problems facing the energy sector in Nigeria. The possible consequences of the lightning effect on the consumers are felt in the increased power blackouts in the affected areas. This leads to loss of revenue from the power transmission companies, consumers and the society at large. This paper x-rays the possible causes, and proffers solution and recommendations on the way forward.
Keywords: Afam power plant, Lightning, Nigeria, power lines
SURVEY OF THE REFLECTIVITY OF THE EARTH’S ATMOSPHERE OVER SOME SELECTED CITIES IN NIGERIA (Published)
Solar radiation is rapidly gaining ground as a supplement to the non renewable sources of energy, which have a finite supply. But the amount of solar radiation reaching the Earth’s surface depends on the climatic and atmospheric conditions of the locations. This work evaluates the temporal and spatial variability of the reflectivity of the Earth’s atmosphere over Ibadan, Enugu, Sokoto and Kano, in order to access the effect of the atmospheric conditions on solar radiation in the areas. The data used for this study were obtained from the International Institute of Tropical Agriculture, Ibadan (1980-2010). The model for shortwave solar energy balance at the edge of the Earth’s atmosphere was adopted in this work. The results show that seasonally, the reflectivity obtained in this work ranged from 0.52 – 0.64, 0.46-0.55, 0.38-0.53, and 0.41-0.57 for Oyo, Enugu, Sokoto and Kano respectively. Annually, the reflectivity obtained ranged from 0.48-0.65, 0.36-0.64, 0.22-0.50 and 0.36-0.60 for Ibadan, Enugu, Sokoto and Kano respectively. This result may be due to the influence of the dry, dusty tropical-continental air mass and the warm, tropical-maritime air mass which control the atmospheric conditions of Nigeria. The atmospheric conditions of the selected cities for the period under review vary from being cloudy, heavily laden with harmattan dust, cloudless (clear) to dustless (clean), hence there is high prospect of solar technology in the areas. This information is useful to solar energy technology, environmental engineers and for climatic modeling. The results obtained were compared with the results of other places having almost latitudinal location and co-ordinates similar to the selected cities.
Keywords: : Reflectivity, Earth’s atmosphere, Nigeria, Renewable Energy, Solar Radiation
TRENDS AND VARIATIONS OF MONTHLY MEAN MINIMUM AND MAXIMUM TEMPERATURE DATA OVER NIGERIA FOR THE PERIOD 1950-2012. (Published)
The monthly mean maximum and minimum temperature data were analysed with the aim of revealing spatial and temporal pattern of long-term trends in the variables. The study is based on the data collected from Nigeria Meteorological Agency’s network of meteorological stations spread across Nigeria spanning from 1950-2012. A total of 20 meteorological stations spread across Nigeria were used for the analysis. Statistical techniques such as time-series plots, correlation analysis, descriptive statistics and Mann-Kendall’s test were used for the analysis. These analyses were executed using the R programming language, MATLAB and SPSS computer software packages. The results show latitudinal dependence of basic temperature characteristics with the northern part of the country exhibiting higher temperature variability than the south. The Mann-Kendall tests indicate that 17 stations (representing 85%) show significant increasing trends in the minimum temperature at the 0.01 level of significance while 16 stations (representing 80%) show significant increasing trends in the maximum temperature at the 0.01 and 0.05 significance levels. Port Harcourt and Ikeja have greatest trend coefficients among the 20 stations. The minimum temperatures have higher trend coefficients than the maximum temperatures for almost all the stations. The interstation spatial coherence revealed by correlation coefficients indicates that almost all the station’s minimum and maximum temperatures are positively correlated with others at the 0.01 level of significance. The Mann-Kendall’s test results show a general warming trend across the stations.
Keywords: Mann-Kendall, Nigeria, Trends, maximum temperature, minimum temperature, variability