Browsing by Author "Alemayehu, Bemenet"

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    Measuring Radon Concentration using Filtered air Samples
    (Addis Ababa University, 2006-07) Alemayehu, Bemenet; Tesfaye, Tilahun (PhD)
    Suction pump was used to pass a known volume of air through Whatman glass fiber filter (> 90 % filtration efficiency). Aerosols deposited on the filter were placed under end-window GM tube with in a minute after the end of sampling, and gross β- count was recorded for successive intervals of time over a period of 7 to 10 hours. The activity concentration of radon daughters was determined by fitting the observed gross β- count to a mathematical model. The diurnal variation of EEC of 222Rn and 220Rn in the nuclear physics lab was observed. It was found that the highest EEC was during the morning hours and the lowest in the afternoon. The daily average equilibrium equivalent concentrations were 23.9 Bq/m3 and 5.2 Bq/m3 for 222Rn and 220Rn respectively