• Title/Summary/Keyword: 소선원

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Frequency Distribution Characteristics of Formation Density Derived from Log and Core Data throughout the Southern Korean Peninsula (남한지역 검층밀도 자료의 특성 분석)

  • Kim, Yeonghwa;Kim, Ki Hwan;Kim, Jongman;Hwang, Se Ho
    • The Journal of Engineering Geology
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    • v.25 no.2
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    • pp.281-290
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    • 2015
  • Log density data were collected and compared with the core density data throughout the southern Korean Peninsula. The comparison reveals that the log densities obtained from gamma-gamma log are much lower than the core densities obtained from laboratory density measurement of core samples. The anomalously low log densities can be attributed to the small-source density log data. Correlation analysis reveals differences between densities derived from the two methods, indicating that a data quality problem arises when using small-source log data. The problem is probably due to the fact that small-source data have not been obtained under ideal conditions for maintaining the appropriate relationship between gamma response and formation density. The frequency distribution characteristics of formation density in the southern Korean Peninsula could be determined using the core and the standard-source log data which are well-correlated.

강내 조사용 $^192$Ir 치료선원 제조

  • 조운갑;한현수;박춘득;홍순복;최태진
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05b
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    • pp.757-762
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    • 1998
  • “하나로”를 이용하여 강내 조사용으로 사용되는 $^{192}$ Ir 선원의 제조법을 확립하였다. HTS (Hydraulic Transfer System)조사공에서 48시간 조사한 $\psi$2.5 mm x t 0.25 mm의 원판형 Ir 표적 10장을 쌓아서 방사능이 1.012 Ci인 선원을 시험제조하였다. 선원 제작에 관련된 생성방사능, 중성자 자기홉수효과 인자를 이론적으로 계산하여 시험제조에 사용하였고 ${\gamma}$선 자기흡수효과는 실험으로 측정하여 암 치료에 요구되는 10-20 Ci 선원의 상용생산에 필요한 자료를 확보하였다. 치료용 소선원 제작에 관련된 표적제작, 중성자조사, 방사능 측정, 선원조립, 밀봉용접, 품질관리 등의 제작기술을 확립하고 선원의 안전성은 밀봉시험, 표면오염검사 등을 수행하여 확인하였다. 제조된 선원은 실제 사용되는 조사장치에 장착하여 기능시험을 수행할 것이다. 이번 실험을 통하여 강내 조사용으로 사용되는 10-20 Ci 방사능의 $^{192}$ Ir 선원을 안정적으로 공급할 수 있음을 확인하였으며 하나로를 이용하여 캡슐 직경 4 mm의 치료용 소선원 제작기술을 확립하였다. 개발된 /spp 192/Ir 강내 조사용 선원은 국내 5-6개 병원에 공급할 것이며 이 기술을 바탕으로 직경 1.1-1.6 mm의 강내 조사용 선원도 개발할 예정이다.

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A study on the construction of aafer citadel (보다 안전한 선원대피처 구축에 관한 연구)

  • Ha, Weon-Jae
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.3
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    • pp.318-324
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    • 2014
  • A Citadel is a designated pre-constructed space in the ship for the crew protection, in the event of imminent boarding by pirates. A Citadel is to be designed and constructed to resist for a certain period against pirate attack. A Citadel constructed in secret place of the ship based on the provisions of international and national requirements, is the last refuge from the pirates attack. This study try to identity identify the limitation and weakness of the current Citadel and suggest to applicable improvement on the Rules for Ship's Facilities for safer and more secure Citadel.

Determination of Exposure Dose Rate and Isotropic Distributions of Substitute High Dose Rate Ir-192 Source for Co-60 Brachytherapy Source (원격강내조사용 Co-60 선원의 대체용 Ir-192 선원의 조사선량결정 및 선량 등방성조사)

  • 최태진;원철호;김옥배;김시운;김금배;조운갑;한현수;박경배
    • Progress in Medical Physics
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    • v.9 no.1
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    • pp.55-64
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    • 1998
  • In recent, the demand of development of the high dose rate brachytherapy source increased for substitute for Co-60 source by iridium source, since the supplying Co-60 source is very depressed and the high dose rate brachytherapy sources are entirely imported from the abroad. This study investigated the exposure rates and isotropic dose distributions for the Ir-192 source produced from $\^$191/Ir(n,r)$\^$192/Ir by nuclear reactor in Korea Atomic Energy Research Institute. The activity of source was obtained an 1.012 Ci (the initial activity without encapsulation was 2,87Ci) by measurement with encapsuled stainless steel. The exposure rate of provided Ir-192 source was determined on 6.36 ${\pm}$ 0.147 Rm$^2$/h-GBq (2.350 ${\pm}$ 0.054 Rcm$^2$/mCi-hr) within ${\pm}$ 2.2% discrepancy with IC-10 ion chamber (0.14 cc) which was mounted on the acrylic jig to 5, 10 and 20 cm from the center of source. The calculated doses with 22 most significant spectrum lines were corrected with intrinsic efficiency of the germanium detector were compared to measured exposure dose rates within ${\pm}$3.8 % discrepancy. The authors confirmed the high dose rate Ir-192 source could be replaced the long decayed Co-60 source via investigation of the isotropic dose distributions in lateral, source axis and diagonal direction of source center are very closed to within 3% uncertainties. Especially, this exposure rate constant and isotropic dose distribution will be fundamental to build the high dose rate source and develop the computed therapy planning system.

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