• Title/Summary/Keyword: 라돈 위해성

Search Result 42, Processing Time 0.035 seconds

The Study on Reduction of Hazardous Materials using Eco-friendly Charcoal Composite Sheet (친환경 활성탄 복합시트의 유해물질 저감 연구)

  • Choi, Il-Hong;Kang, Sang-Sik;Lee, Su-Min;Yang, Seung-Woo;Kim, Kyo-Tae;Park, Ji-Koon
    • Journal of the Korean Society of Radiology
    • /
    • v.12 no.5
    • /
    • pp.615-621
    • /
    • 2018
  • Recently, various environmentally friendly products have been developed for improving the indoor air quality while pursuing a well-being nature-friendly healthy life as a core value. In this research, we not only solve the problems of existing environmentally friendly paints, but also developed a charcoal composite seats that can reduce radon, which is a natural radioactive substance, and evaluated the reduction effect of radon, formaldehyde and volatile organic compounds. In the charcoal composite seats, a sodium silicate emulsion and charcoal were mixed to prepare an charcoal liquid coating material, and the composite seats was fabricated by air-spray coating method. In order to analyze the hazardous substance reduction performance of the fabricated charcoal composite seats, radon was designed to comply with the Ministry of the Environment standard, formaldehyde and volatile organic compounds were designed to comply with KCL-FIR-1085 standard. As a result of the experiment, the fabricated charcoal composite seats was evaluated as having a radon reduction capability of about 90.8% from 20 hours, formaldehyde and volatile organic compounds were 3 hours, and the reduction capability of 96.7% and 96.6% was found respectively. It is considered that these results can be utilized as basic data at the time of product development for improvement of indoor air quality.

Geochemical Origins and Occurrences of Natural Radioactive Materials in Borehole Groundwater in the Goesan Area (괴산지역 시추공 지하수의 자연방사성물질 산출특성과 지화학적 기원)

  • Kim, Moon Su;Yang, Jae Ha;Jeong, Chan Ho;Kim, Hyun Koo;Kim, Dong Wook;Jo, Byung Uk
    • The Journal of Engineering Geology
    • /
    • v.24 no.4
    • /
    • pp.535-550
    • /
    • 2014
  • The origins and varieties of natural radioactive materials, including uranium and radon-222, were examined in a drilled borehole extending to a depth of 120 m below the surface in the Goesan area. In addition to core samples, eight groundwater samples were collected at different depths, using a double packer system and bailer, and their geochemical characteristics were determined. Most of the rock samples from the drilled core consisted of granite porphyry, with sedimentary rocks (slate, carbonate, or lime-silicates) and pegmatite occurring in certain sections. The pH of samples varied from 7.8 to 8.4, and the groundwater was of a Na-$HCO_3$type. Uranium and thorium concentrations in the core were < 0.2-14.8 ppm and 0.56-45.0 ppm, respectively. Observations by microscope and an electron probe microanalyzer (EPMA) showed that the mineral containing the natural radioactive materials was monazite contained in biotite crystals. The uranium, which substituted for major elements in the monazite, appeared to have dissolved and been released into the groundwater in a shear zone. Concentrations of Radon-222 in the borehole showed no close relationship with levels of uranium. The isotopes of noble gases, such as helium and neon, would be useful for analyzing the origins and characteristics of the natural radioactive materials.

Direction finding based on Radon transform in frequency-wavenumber domain with a sparse array (주파수-파수 스펙트럼과 라돈변환을 이용한 희소 배열 기반 방위추정 기법 연구)

  • Choi, Yong Hwa;Kim, Dong Hyeon;Kim, J.S.
    • The Journal of the Acoustical Society of Korea
    • /
    • v.38 no.2
    • /
    • pp.168-176
    • /
    • 2019
  • When an array receives a signal with a frequency higher than the design frequency, there is an ambiguity in beamforming due to spatial aliasing. In order to overcome this problem, Abadi proposed frequency-difference beamforming. However, there is a constraint that the minimum frequency bandwidth is required according to the value of the difference frequency. In this paper, we propose a method to find the direction of the target signal with spatial aliasing based on the frequency-wavenumber spectrum combined with Radon transform. The proposed method can estimate the direction of the target without ambiguities when the signal has nonnegligible bandwidth. We tested the algorithm by simulating a broadband signal and verified the results with the frequency-difference beamforming method using SAVEX15 (Shallow Water Acoustic Variability EXperiment 2015)'s shrimp noise data.

The study on the quality standards of groundwater in Korea in comparing to the developed countries (우리나라와 선진국간의 지하수 수질기준에 관한 고찰)

  • Bang, Sang-Weon;Jung, Jae-Hyun
    • Journal of Environmental Policy
    • /
    • v.4 no.2
    • /
    • pp.57-82
    • /
    • 2005
  • In this study, we propose methods for. the efficient management and integrity of groundwater in response to a diminishing supply. As an alternative water resource for the future. we investigated and comparatively analyzed the quality standards of groundwater in the US (New York, Wisconsin and Texas), Austria, Netherlands, Canada, Japan and United Kingdom. These developed countries heavily depend on groundwater, more than 70%, for drinking water and apply those drinking water standards to groundwater quality. However, there exists few differences in the quality standards of groundwater among the countries, because each country possesses its own individual environment and management. In Korea, surface water pollution is getting serious and its water resources are diminishing. Therefore we propose several new quality criteria that many countries regulate at these days for their efficient management of groundwater. There is a need to divide BTEX criterion into Benzene, Toluene, Ethylbenzene and Xylene, individually. In. addition, it is needed to establish BTEX criteria into agricultural water and industrial water use standards as well as daily life use standards. Also, regulations for some PAHs, showing carcinogenicity, are required. Due to rapid industrialization various hazardous chemicals were utilized and their uses are increasing each year. Therefore, there is a strong need to introduce n~w standards and tighter regulations of the levels. At the same time, the criterion of nitrogenous compounds need' to be regulated individually in order to prevent the damage incurred by the compounds. Several developed countries have established standards for radon, previously caused environmental accidents in Korea. Therefore, we propose the necessity of groundwater quality standards for radon in this study.

  • PDF

Synthesization and Characterization of Pitch-based Activated Carbon Fiber for Indoor Radon Removal (실내 라돈가스 제거를 위한 Pitch계 활성탄소섬유 제조 및 특성연구)

  • Gwak, Dae-Cheol;Choi, Sang-Sun;Lee, Joon-Huyk;Lee, Soon-Hong
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.15 no.3
    • /
    • pp.207-218
    • /
    • 2017
  • In this study, pitch-based activated carbon fibers (ACFs) were modified with pyrolysis fuel oil (PFO). Carbonized ACF samples were activated at $850^{\circ}C$, $880^{\circ}C$ and $900^{\circ}C$. A scanning electron microscope (SEM) and a BET surface area apparatus were employed to evaluate the indoor radon removal of each sample. Among three samples, the BET surface area and micropore area of ACF880 recorded the highest value with $1,420m^2{\cdot}g^{-1}$ and $1,270m^2{\cdot}g^{-1}$. Moreover, ACF880 had the lowest external surface area and BJH adsorption cumulative surface area of pores with $151m^2{\cdot}g^{-1}$ and $35.5m^2{\cdot}g^{-1}$. This indicates that satisfactory surface area depends on the appropriate temperature. With the above scope, ACF880 also achieved the highest radon absorption rate and speed in comparison to other samples. Therefore, we suggest that the optimum activation temperature for PFO containing ACFs is $880^{\circ}C$ for effective indoor radon adsorption.

Development of Infrared Imaging Measurement Device for Internal Red Ginseng Analysis. (홍삼 내부 분석을 위한 적외선 영상 측정기기 개발)

  • Park, Jaeyoung;Kim, Taehoon;Jung, Seokhoon;Kim, Donggeun;Cho, Se-Hyoung;Han, Chang Ho;Lee, Sangjoon;Lee, Ji Yeon;Ko, Kuk Won
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2017.04a
    • /
    • pp.573-576
    • /
    • 2017
  • 본 연구는 홍삼 등급판정 과정에서 내부 조직 치밀도 분석을 위해 의료 영상 분석 방법을 이용하여 적외선 영상 측정기기를 개발하였다. 기존 홍삼 내부분석방법은 수동으로 암실환경에서 강한 조명을 홍삼에 투과하여 사람 눈으로 직접 판별하는 과정을 거친다. 이러한 기존 검사 과정은 작업 비효율성과 불균일한 검사기준으로 제품 품질 신뢰도 저하의 단점을 가져온다. 이러한 문제점을 해결하기 위해 본 연구는 적외선 조명환경에서 자동 측정이 가능한 홍삼 내부 측정기기를 개발하였다. 개발된 장치는 홍삼의 빛 투과 특성을 응용한 920nm 파장대역의 적외선 조명기구, 조명 제어회로, 적외선 대역 촬영이 가능한 영상 측정 카메라 장치, $0.9^{\circ}$의 간격으로 $360^{\circ}$ 홍삼 영상취득이 가능한 회전 엑츄에이터로 구성이 된다. 본 연구에서 제안 하는 홍삼 단층 영상분석 방법은, 홍삼을 $0.9^{\circ}$ 간격으로 회전시키어 $360^{\circ}$ 홍삼 내부영상을 취득하여 라돈 변환(Radon transform)을 통해 사이노그램(Sinogram)으로 재구성 하였으며, 역 라돈 변환(Inverse Radon transform)을 통해 단층 영상복원(Back-projection)알고리즘을 구현하였다. 이 결과 홍삼을 절단하지 않고 홍삼 내부 단면영상 획득이 가능하였으며 내공(內空), 내백(內白)의 유무를 판단하고 직경을 파악할 수 있었다. 이를 토대로 등급 판별 공식을 산출하면 신뢰성 있는 홍삼 등급 자동화 측정기기를 개발할 수 있을 것으로 기대된다.

Radionuclides of Ground waters in Busan (부산지역 지하수의 방사성물질 특성)

  • Jeon, Dae-Young
    • Journal of Soil and Groundwater Environment
    • /
    • v.14 no.5
    • /
    • pp.51-61
    • /
    • 2009
  • This study was performed to research the characteristic of radionuclides of 80 groundwater monitoring networks in Busan. According to the research, average concentration of Uranium was $4.33\;{\mu}g/L$, maximum concentration of Uranium was $171.55\;{\mu}g/L$ among the 80 sampling sites. One sample exceeded the Proposal standard of drinking water in USA in Uranium ($30\;{\mu}g/L$) and four samples exceeded the recommendatory value of WHO about Uranium ($15\;{\mu}g/L$). Radon and gross-$\alpha$ concentration of all samples were far less than the Proposal standard of drinking water in USA. In this study average concentration of radionuclides in underground water wasn't too high, but needed to control the concentration of them to prevent exposure to the people. And it needs to be taken measures in some sites with high concentration of Uranium by closing the pipe line or etc through more studies.

Relationship of Radon-222 and Chemical Composition of Groundwater as a Precursor of Earthquake (지진 전조인자로서 지하수내 라돈 및 화학성분의 상관성 연구)

  • Jeong, Chan Ho;Park, Jun Sik;Lee, Yong Cheon;Lee, Yu Jin;Yang, Jae Ha;Kim, Young Suk;Ou, Song Min
    • The Journal of Engineering Geology
    • /
    • v.28 no.2
    • /
    • pp.313-324
    • /
    • 2018
  • In order to study the earthquake precursor in the Korean peninsula, long-term variations of chemical composition, radon-222, and water level were measured at depths (-60 m, -100 m) in the groundwater monitoring wells of the Daejeon and the Cheongwon area. The pH and electrical conductivity of groundwater in the monitoring wells showed some relationship with the Pohang earthquake. The ${HCO_3}^-$ and $Cl^-$ concentration of groundwater in the Daejeon and $Mg^{2+}$, $Cl^-$ and ${NO_3}^-$ in the Cheongwon showed some relation with the Pohang earthquake. However, it is not distinct to find the relationship between their variation and earthquake. The radon-222 concentration in Daejeon was observed a significant increase from a minimum of 162 Bq/L prior to the earthquake to 573 Bq/L right after the earthquake, that indicating a strong correlation with earthquakes. In the case of groundwater levels, it can not find some correlation between earthquakes and continuous decreasing trend in the monitoring wells of Daejeon and Cheongwon area. However, water level of a national groundwater observation well within 10 kilometers of Pohang epicenter was recorded as an abrupt drop right before the earthquake. Conclusively, although the location of monitoring wells is more than 180 kilometers apart from the epicenter of the Pohang earthquake, the radon gas in groundwater can be considered as a reliable candidate among earthquake precursors. The pH, electrical conductivity, ${HCO_3}^-$ and $Cl^-$ among hydrochemicals showed some correlation with earthquake should be monitored during a longer term to recognize distinctly as a precursor of earthquake.

Investigation on the petroleum contamination by using Rn-222 tracer (라돈 추적자를 이용한 유류오염에 대한 연구)

  • Yoon, Yoon-Yeol;Koh, Dong-Chan;Lee, Kil-Yong;Cho, Soo-Young;Ko, Kyung-Seok
    • Analytical Science and Technology
    • /
    • v.25 no.1
    • /
    • pp.14-18
    • /
    • 2012
  • Rn-222 was used as a natural radioactive isotope tracer to evaluate non-aqueous phase liquid(NAPL) contaminated soil and aquifer. In the case of soil sample, Rn-222 concentration was inversely decreased with diesel concentration in the granite soil sample and it was decreased about 30% at the 13% diesel contaminated soil. For evaluating trichloroethylene (TCE) contaminated aquifer, the natural radioisotope Rn-222 was used as naturally occurring partitioning tracer for the approximate localization and semiquantitative assessment of the TCE source zone. Rn-222 was analyzed for the estimation of TCE contamination ranges of the acquifer in the contaminated site at Wonju in Korea.