• Title/Summary/Keyword: 방사성탄소

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Preparation of Electrospun PI-based ACF Web for Electrode of Electric Double Layer Capacitior(EDLC) (정전기 방사에 의한 EDLC 전극용 폴리이미드계 활성탄소섬유 웹의 제조)

  • Choi, Young-Ok;Kim, Chan;Yang, Gab-Seung
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.134-137
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    • 2003
  • 탄소섬유나 활성탄소섬유(activated carbon fiber, ACF)는 일반적으로 출발물질에 따라 polyacrylonitrile(PAN)계, 아크릴(acryl)계, 피치(pitch)계, 페놀(phenol)계 등으로 분류할 수 있다. 보통 습식, 용융 혹은 용융분사(melt-blown) 방사 방법에 의해 섬유 형태로 형성한 다음 산화성 가스 분위기에서 불융화 과정을 거쳐 열에 대한 안정성을 부여하여 불활성 분위기에서 탄소화하여 탄소섬유를 제조하거나, 수증기나 이산화 탄소와 같은 산화성 분위기에서 활성화하여 활성탄소섬유를 제조한다. (중략)

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악티늄족 및 란탄족 원소 회수를 위한 기능성 고분자-탄소 나노 구조체

  • Jeong, Yong-Ju;Sim, Jun-Bo;Baek, Seung-U;Kim, Si-Hyeong;Gwon, Sang-Un;Kim, Gwang-Rak;Jeong, Heung-Seok;An, Do-Hui
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2009.11a
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    • pp.198-199
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    • 2009
  • 킬레이팅 고분자를 메조기공 탄소 표면 위에 흡착시킴으로써 금속이온과 착물을 형성할 수 있는 기능성 나노구조체를 제조하였다. 악티늄족 원소를 단일입자 내에 영구처분을 위한 예비연구로서 Eu을 대용물(surrogate)로 사용하여 기능성 나노 구조체에 주입한 후 메조기공 입구를 고분자반응을 통해 봉쇄함으로써 Eu의 단일입자 내 고정화를 시도하였다. 시간에 따라 침출현상을 분석한 결과, 고분자로 메조기공을 blocking 하였을 때 Eu의 침출현상이 크게 완화되는 것을 확인하였다. 이는 시멘트화나 유리화 등과 같은 고비용 공정을 거치지 않고도 단일입자 내 유해 금속의 영구처분이 가능하다는 것을 의미한다. 더 나아가, 이러한 접근방법은 지지체로 메조기공 탄소에 국한되지 않고 실리카와 같은 다른 메조기공 금속산화물에 적용될 수 있다는 점에서 큰 강점이 있다.

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Introduction of Barcelona Basic Model for Analysis of the Thermo-Elasto-Plastic Behavior of Unsaturated Soils (불포화토의 열·탄소성 거동 분석을 위한 Barcelona Basic Model 소개)

  • Lee, Changsoo;Yoon, Seok;Lee, Jaewon;Kim, Geon Young
    • Tunnel and Underground Space
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    • v.29 no.1
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    • pp.38-51
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    • 2019
  • Barcelona Basic Model (BBM) can describe not only swelling owing to decrease in effective stress, but also wetting-induced swelling due to decrease in suction. And the BBM can also consider increase in cohesion and apparent preconsolidation stress with suction, and decrease in the apparent preconsolidation stress with temperature. Therefore, the BBM is widely used all over the world to predict and to analyze coupled thermo-hydro-mechanical behavior of bentonite which is considered as buffer materials at the engineered barrier system in the high-level radioactive waste disposal system. However, the BBM is not well known in Korea, so this paper introduce the BBM to Korean rock engineers and geotechnical engineers. In this study, Modified Cam Clay (MCC) model is introduced before all, because the BBM was first developed as an extension of the MCC model to unsaturated soil conditions. Then, the thermo-elasto-plastic version of the BBM is described in detail.

An Analysis of Carbon-14 Metabolism for Internal Dosimetry at CANDU Nuclear Power Plants (중수로 원전 종사자의 방사선량 평가를 위한 $^{14}C$ 인체대사모델 분석)

  • Kim, Hee-Geun;Lee, Hyung-Seok;Ha, Gak-Hyun
    • Journal of Radiation Protection and Research
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    • v.28 no.3
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    • pp.207-213
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    • 2003
  • Carbon-14 is one of the major radionuclides released by CANDU Nuclear Power Plants(NPPs). It is almost always emitted as gas through the stack. From CANDU NPPs about 95% of all carbon-14 is released as carbon dioxide. Carbon-14 is a low energy beta emitter which, therefore, gives only a small skin dose from external radiation. As carbon dioxide Is physiologically rather inert gases for man's metabolism, the inhalation dose is probably less than 1 % of the ingestion dose. But this source of carbon-14, formed in a closed, nor-oxidative environment, was subsequently released into the workplace as an insoluble particulate when these systems were opened lip for re-tubing at CANDU NPPs. As a part of the improvement of dosimetry program at Wolsong Nuclear Power Plants, the carbon-14 metabolism based on references was investigated and studied to setup the internal dosimetry program due to inhalation of carbon-14.

Radio-Carbon Age Determination by Tandem Accelerator Mass Spectrometry Technique and Its Application To The Korean Sea (탄뎀가속기에 의한 방사성탄소 년대측정과 한국해에의 적용)

  • Suk, Bong-Chool;Toshio Nakamura;Nobuyuki Nakai;Asahiko Taira
    • The Korean Journal of Quaternary Research
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    • v.4 no.1
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    • pp.27-40
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    • 1990
  • $^{14}C$ age dating by AMS (accelerator mass spectrometry) technique was performed on twenty five small sized fossil shells and one peat taken from the sixteen piston cores in the southern and southeastern Korean Sea. AMS technique is available to date only a few milligram of amorphous carbons compare than conventional dating technique. It is described in detail of sample pre-treatment and experimental, and applied to the reconstruction of the sea level changes since the late Pleistocene in the Korean Sea. Dated age ranges from 520$\pm$100 to older than 33,500 years. Sedimentary facies in the study area represents a different environmental set which is affected by sea level fluctuation since the late Pleistocene.

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Monitoring and Analytical Techniques for the Discharged Radiocarbon from Nuclear Facility (핵시설로부터 발생되는 방사성탄소 분석기술 및 감시)

  • Chun, Sang-Ki;Kim, Nak-Bae;Kim, Kun-Han;Choi, Su-Young;Park, Chan-Jo;Lee, Joung-Dae;Shin, Jang-Sik
    • Analytical Science and Technology
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    • v.13 no.6
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    • pp.693-698
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    • 2000
  • The object of this series of experiments was aimed for the systematic and long-term radioactivity monitoring through indirect search of C-14 concentration level changes in the natural conditions around the operating nuclear facilities. The result of environmental radioactivity level through tree-ring analysis is increased after operating nuclear facilities and such a level can be proved to relate power generation closely. The measured result of ${\delta}^{13}C$ through the treatment of cellulose can be showed the level -30‰. This figure is very different from one which is measured the -17‰ of air sample by passive air sampling and -8‰ of air sample by active air sampling. And these differences can be assumed as isotope fractionation by photosynthesis, but the problem is more study as needed.

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토륨 핵연료의 핵적 타당성 연구 - 가압경수로용 탄소피막 핵연료 적용 -

  • 임재용;김명현;주형국
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.10a
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    • pp.171-176
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    • 1997
  • Th-232를 Fertile로 사용한 핵연료는 U-238을 Fertile로 사용한 핵연료보다 핵확산 저항성, 방사성 폐기물 생성면에서 유리하다. 본 연구에서는 MHTGR의 핵연료에 사용된 탄소피막 입자 기술을 토륨 핵연료에 적용하여 새로운 가압경수로용 핵연료로 개념 설계하였다. 핵연료의 설계안을 울진 3,4호기 집합체 설계안에 적용하여 해적 타당성을 살펴보았다.

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