• Title/Summary/Keyword: Radon measure

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Concentration Distributions and A Reduction Strategy of Airborne Radon in Seoul Metropolitan Subway Stations (서울시 지하철역내의 라돈 농도분포 및 저감대책)

  • 김동술;김윤신;김신도;신응배;김성천;유정석
    • Journal of Korean Society for Atmospheric Environment
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    • v.9 no.4
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    • pp.271-277
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    • 1993
  • Indoor radon has been known as one of the notorious carcinogens. However, a safe environmental criterion of radon has not yet been established in Korea, The main objectives of this study were to study concentration distributions of radon, to trace radon sources in subways, and to obtain a strategy for radon reduction in Seoul metropolitan area. Radon concentrations had been extensively determined by several steps. The first step was to survey radon levels in all of 83 subway stations from October to November in 1991. The second step was to select 40 out of 83 stations and then to study seasonal variations in 1991 and 1992. The third step was to monitor radon levels by hourly-basis plans. The fourth step was to seek a radon reduction strategy by altering ventilation at Ankuk station where had the highest radon concentration during the first measurement step. Each underground floor in the station was divided into 10 sites to measure hourly radon variations. The final step of the study was to measure radon concentrations in groundwater that is one of the possible main sources radon place. The result of the various measuring approaches showed short-and long-term radon variation and indicated radon reduction schemes.

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Fuzzy Measure and Integration

  • Stojakovic, Mila
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1418-1421
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    • 1993
  • The main purpose of this paper is to introduce and develop the notion of a fuzzy measure in separable Banach space. This definition of fuzzy measure is a natural generalization of the set-valued measure. Radon-Nikod m theorems for fuzzy measure are established.

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A Survey of Indoor and Outdoor Radon Concentrations by Alpha Track Detector in Korea (Alpha Track Detector를 이용한 실내외 라돈 농도조사에 관한 연구)

  • ;;;Takao Iida
    • Journal of Environmental Health Sciences
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    • v.28 no.5
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    • pp.71-76
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    • 2002
  • A survey of radon concentrations in both indoor and outdoor atmospheres was carried out using EIRM and Cup Monitor for the period of February 1996 to March 1997. EIRM were used to measure the indoor and outdoor radon concentration at five major cities university. Cup Monitor were also used to measure the indoor radon concentrations at shopping store, office building, apartment, hospital and house in Seoul. The mean indoor and outdoor radon concentrations at the five major cities(Seoul, Daegu, Daejon, Cwangiu and Busan) were 24.1 Bq/m$^3$and 8.62 Bq/m$^3$, respectively. The ratio of indoor to outdoor radon concentrations ranged front 1.7 to 3.9. Inspection of its seasonal distribute pattern indicates the enhancement during winter relative to summer, consistently for both indoor and outdoor air. The results of the survey showed that the concentrations in basements were clearly higher than those in usual living/working places.

The Design and Implementation of IoT-Based Radon Measurement Control System (IoT 기반 라돈 측정 제어시스템 설계 및 구현)

  • Ahn, Heuihak;Gu, Jayeong;Lee, Sangyoon
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.16 no.1
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    • pp.1-10
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    • 2020
  • This paper is a IoT-based radon meter control system and a radon meter control method using it. The IoT-based radon meter control system is control system for controlling a radon meter by network-connecting radon meter and a user terminal. The radon measuring device may be provided with a radon sensor to measure a radon value of a preset management target area, it collect and store numerical data. The radon meter control system monitors the condition of the radon meter, it includes control center configured to deliver radon meter management information generated to a user terminal. Also radon measurements to determine the exact amount of radon gas. Therefore, the situation-specific actions based on radon numbers can be promptly implemented to ensure adequate protection for those who are vulnerable to radon and those who live in the area. Condition monitoring allows the radon meter to respond quickly to failure or failure of the radon meter. In addition, it is possible to secure a baseline of radon's influence and to obtain research data to cope with radon by establishing big data with radon measurements.

A preliminary study on real-time Rn/Tn discriminative detection using air-flow delay in two ion chambers in series

  • Sopan Das ;Junhyeok Kim ;Jaehyun Park ;Hojong Chang;Gyuseong Cho
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4644-4651
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    • 2022
  • Due to its short half-life, thoron gas has been assumed to have negligible health hazards on humans compared to radon. But, one of the decay products with a long half-life can make it to be transported to a long distance and to cause a severe internal dose through respiration. Since most commercial radon detectors can not discriminate thoron signals from radon signals, it is very common to overestimate radon doses which in turn result in biased estimation of lung cancer risk in epidemiological studies. Though some methods had been suggested to measure thoron and radon separately, they could not be used for real-time measurement because of CR-39 or LR-115. In this study, an effective method was suggested to measure radon and thoron separately from the free air. It was observed that the activity of thoron decreases exponentially due to delay time caused by a long pipe between two chambers. Therefore from two ion chambers apart in time, it was demonstrated that thoron and radon could be measured separately and simultaneously. We also developed a collimated alpha source and with this source and an SBD, we could convert the ion chamber reading to count rate in cps.

CONSTRUCTIONS OF SEGAL ALGEBRAS IN L1(G) OF LCA GROUPS G IN WHICH A GENERALIZED POISSON SUMMATION FORMULA HOLDS

  • Inoue, Jyunji;Takahasi, Sin-Ei
    • Journal of the Korean Mathematical Society
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    • v.59 no.2
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    • pp.367-377
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    • 2022
  • Let G be a non-discrete locally compact abelian group, and 𝜇 be a transformable and translation bounded Radon measure on G. In this paper, we construct a Segal algebra S𝜇(G) in L1(G) such that the generalized Poisson summation formula for 𝜇 holds for all f ∈ S𝜇(G), for all x ∈ G. For the definitions of transformable and translation bounded Radon measures and the generalized Poisson summation formula, we refer to L. Argabright and J. Gil de Lamadrid's monograph in 1974.

Measurement of the radon and thoron exhalation rates from the water surface of Yixin lake

  • Jiulin Wu;Shuaibin Liu;Tao Hu;Fen Lin;Ruomei Xie;Shuai Yuan;Haibo Yi;Yixiang Mo;Jiale Sun;Linquan Cheng;Huiying Li;Zhipeng Liu;Zhongkai Fan;Yanliang Tan
    • Nuclear Engineering and Technology
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    • v.56 no.4
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    • pp.1538-1543
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    • 2024
  • The importance of determining the radon exhalation rate from water surface is emphasized by the increased use of radon and its daughter products as tracers in large-scale circulation studies of the atmosphere. There were many methods to measure radon exhalation from water surface. With the development of radon exhalation rate measurement methods and instruments on the surface of the soil, the rock and building materials, so the radon exhalation rate from water surface can be more accurately measured by applying these improved methods and instruments. In this paper, a cuboid accumulation chamber surrounded by foam boards and a RAD7 were used to measure the radon exhalation rate on the water surface at three different positions by Yixin lake. Each measurement was performed 2 h. The radon exhalation rate from the water surface was about 6 × 10-3 Bq m-2s-1. The thoron exhalation rate from the water surface also can be estimated, it is about 0.16 Bq m-2s-1. These results hint that the radon transmission from the lake bottom soil to water and then into the atmosphere.

Prediction for the Lifetime Effective Dose and Radon Exposure Risk by using Dose Conversion Convention: Base on the Indoor Radon Concentration of Lecture Room in a University (선량 환산 관례를 이용한 생애유효선량 및 라돈피폭 위험도 예측: 대학 강의실 라돈농도 중심으로)

  • Lee, Jae-Seung;Kweon, Dae Cheol
    • Journal of Biomedical Engineering Research
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    • v.39 no.6
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    • pp.243-249
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    • 2018
  • The indoor radon concentration was measured in the lecture room of the university and the radon concentration was converted to the amount related to the radon exposure using the dose conversion convention and compared with the reference levels for the radon concentration control. The effect of indoor radon inhalation was evaluated by estimating the life effective dose and the risk of exposure. To measure the radon concentration, measurements were made with a radon meter and a dedicated analysis Capture Ver. 5.5 program in a university lecture room from January to February 2018. The radon concentration measurement was carried out for 5 consecutive hours for 24 hours after keeping the airtight condition for 12 hours before the measurement. Radon exposure risk was calculated using the radon dose and dose conversion factor. Indoor radon concentration, radon exposure risk, and annual effective dose were found within the 95% confidence interval as the minimum and maximum boundary ranges. The radon concentration in the lecture room was $43.1-79.1Bq/m^3$, and the maximum boundary range within the 95% confidence interval was $77.7Bq/m^3$. The annual effective dose was estimated to be 0.20-0.36 mSv/y (mean 0.28 mSv/y). The life-time effective dose was estimated to be 0.66-1.18 mSv (mean $0.93{\pm}0.08mSv$). Life effective doses were estimated to be 0.88-0.99 mSv and radon exposure risk was estimated to be 12.4 out of 10.9 per 100,000. Radon concentration was measured, dose effective dose was evaluated using dose conversion convention, and degree of health hazard by indoor radon exposure was evaluated by predicting radon exposure risk using nominal hazard coefficient. It was concluded that indoor living environment could be applied to other specific exposure situations.