• Title, Summary, Keyword: 방사조도

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The Moon's Spectral Irradiance Computation using Relative Positions between the Sun, Moon, and the Satellite (태양, 달, 위성의 위치를 이용한 달의 방사조도 계산)

  • Seo, Seok-Bae;Song, Young-Joo
    • Aerospace Engineering and Technology
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    • v.12 no.1
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    • pp.152-162
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    • 2013
  • The spectral irradiance of the Moon is used to monitor the performance of on-board satellite's visible channel detectors. This paper established a method to compute the spectral irradiance of the Moon using the relative positions between the Sun, Moon, and the COMS (Communication, Ocean, Meteorological Satellite), which is generated through the COMS FDS (Flight Dynamics Subsystem). The established computation method is applied to the algorithm which is developed to detect and compensate the degradations of COMS MI (Meteorological Imager) visible channel detectors.

Investigation on the Hydrodynamic Behaviors of the Clarifier with an Interior Baffle in WWTP by using of Radiotracer $^{99m}Tc$ ($^{99m}Tc$ 추적자를 이용한 하수처리 시설 내 침전조의 정류벽 설치 유무에 따른 유체거동 변화측정)

  • Kim, Jin-Seop;Kim, Jong-Bum;Kim, Jae-Ho;Jung, Sung-Hee
    • Journal of Radiation Protection and Research
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    • v.32 no.3
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    • pp.117-122
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    • 2007
  • The hydrodynamic behaviors of the clarifier with an interior baffle in a wastewater treatment plant was investigated by using a radiotracer $^{99m}Tc$(30 40 mCi) to verify the results of CFD(computational fluid dynamics) modelling in the previous study. The clarifier model was manufactured with consideration to the hydraulic similarity(1/21) of a real plant($L{\times}W{\times}H:2.6{\times}0.4{\times}0.2m$). By installation of an interior baffle to the clarifier, the strong density current at the bottom of the clarifier decreased substantially and increased the area of sludge settling zone, which were visualized successfully from the radiotracer experiment. Also the portion of short circuit stream changed from 48 % to 32 % and the mean residence time of sludge decreased from 940 sec to 810 sec, which corresponds to the results of CFD modelling. As a result, it is anticipated that radiotracer technology can be used as an important tool for designing new wastewater treatment plants and verifying their performances after structural modifications.