• 제목/요약/키워드: Ke

검색결과 1,707건 처리시간 0.03초

Measurement of Energy Dependent Neutron Capture Cross Sections of $^{197}Au$ in Energy Region from 0.1 eV to 10 keV using a Lead Slowing-down Spectrometer

  • Yoon, Jung-Ran
    • 한국방사선학회논문지
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    • 제4권4호
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    • pp.29-32
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    • 2010
  • 본 연구는 교토대학 원자로실험소의 46-MeV전자선형가속기에서 발생된 전자선을 Ta표적에 충돌시켜 발생된 중성자를 이용하였다. 발생된 중성자는 납감속측정장치(LSDS:Lead Slowing-down Spectrometer))속에서 감속되었고 중성자비행시간법(TOF:Time-of-Flight)을 이용하여서 중성자에너지를 선별하여 $^{197}Au$의 중성자포획단면적을 중성자에너지 0.1 eV에서 10 keV범위에 걸쳐 측정하였다. 발생된 중성자속을 측정하기 위하여 $BF_3$검출기속의 $^{10}B(n,{\gamma})$반응을 이용하였고 이것을 이용하여 중성자 반응 단면적을 상대적으로 얻었다. TOF방법으로 얻어진 결과는 1 eV에서의 결과(24.5 b)에 규격화되었다. 기존의 실험결과들과 평가결과들인 JENDL/D-99 Dosimetry File과 비교하였다.

Ar 이온빔 조사에 따른 SnO2 박막의 물성 연구 (Effect of Ar Ion Irradiation on the Hydrogen Gas Sensitivity of SnO2 Thin Films)

  • 허성보;이영진;김선광;유용주;최대한;이병훈;김민규;김대일
    • 열처리공학회지
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    • 제25권6호
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    • pp.279-282
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    • 2012
  • $SnO_2$ thin films were prepared on the Si substrate by radio frequency (RF) magnetron sputtering and then surface of the films were irradiated with intense Ar ion beam to investigate the effect of Ar ion irradiation on the properties and hydrogen gas sensitivity of the films. From atomic force microscope observation, it is supposed that intense Ar bombardments promote rough surface and increase gas sensitivity of $SnO_2$ films for hydrogen gas. The films that Ar ion beam irradiated at 6 keV show the higher sensitivity than the films were irradiated at 3 keV and 9 keV. These results suggest that the $SnO_2$ thin films irradiated with optimized Ar ion beam are promising for practical high-performance hydrogen gas sensors.

도전성 카본블랙/PVdF 복합재의 제조 및 전기적 특성 (Fabrication and Electrical Properties of Conductive Carbon Black filled Poly(Vinyliden Fluoride) Composite)

  • 김명찬;문승환;임재석;함현식;박홍수;김명수
    • 한국응용과학기술학회지
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    • 제20권3호
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    • pp.212-220
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    • 2003
  • Electrical properties of carbon filler/PVdF [poly(vinylidene fluoride)] composite were investigated as a funtion of carbon filler/PVdF ratio in the range of 0.2${\sim}$0.5. Three kinds of comercialzied conductive carbon blacks such as Hiblack 41Y, KE300J, and KE600J, and carbon nanofibers prepared by the catalytic chemical vapor deposition of $C_2H_4$ over Ni-Cu catalysts were used as the carbon fillers. The electrical conductivity of carbon filler/PVdF composites were in the range of 0.65 to 13.5 S/cm depending the fillers' electrical conductivity ranging from 5.6 to 23.1 S/cm. Among the carbon fillers used, the KE600J carbon black showed the highest conductivity both in the composite and filler itself because of its high degree of graphitization due to the high-temperature thermal treatment and its high surface area due to the activation treatment.

Simultaneous Observation of FUV Aurora with Precipitating Electrons on STSAT-1

  • Lee, C.N.;Min, K.W.;Lee, J.J.;Kim, K.H.;Kim, Y.H.;Han, W.;Edelstein, J.
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2008년도 한국우주과학회보 제17권2호
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    • pp.31.2-31.2
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    • 2008
  • We present the results offar ultraviolet (FUV, 1350-1750 ${\AA}$) auroral observations made by the Far-ultraviolet IMaging Spectrograph (FIMS) instrument on the Korean microsatellite STSAT-1. The instrument was capable of resolving spatial structures of a few kilometers with the spectral resolution of 2-3 ${\AA}$. The observations were carried out simultaneously with the measurement of precipitating electrons using an electrostatic analyzer (ESA, 100 eV-20 keV) and a solid state telescope (SST, 170 keV-360 keV) on board the same satellite. With a careful mapping of the field lines, we were able to correlate the particle spectrum to the corresponding FUV spectrum of the footprints of the FIMS image that varied significantly in fine scales. We divided the FIMS spectral band into the LBH long (LBHL, 1640-1715 ${\AA}$) and LBH short (LBHS, 1380-1455 ${\AA}$) bands, and compared the electron energies with the intensities of LBHL and LBHS for the well-defined inverted-V structures. The result shows a strong correlation between the total LBH intensity and the energy flux measured by ESAwhile the peak energy itself does not correlate well with the LBH intensity. On the other hand, it was observed that the ratio of the LBHL intensity to that of LBHS increased significantly as the peak electron energy increased, primarily due to a smaller absorption by O2 at LBHL than at LBHS.

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한의학(韓醫學) 외과(外科) 용어(用語) 마도(馬刀)의 의미에 관한 소고(小考) (A Study on Meaning of Mado(馬刀) (Terms of Surgery in Korean Medicine))

  • 구인모;박찬영;이병욱;금기욱
    • 대한한의학원전학회지
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    • 제27권2호
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    • pp.153-162
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    • 2014
  • Objectives : We can discover 'Madohyeobyeong(馬刀挾癭)' and 'Madohyeobyeong(馬刀挾纓)' in LingShu(靈樞). But the meaning of them are not clear. Especially mean of 'Mado(馬刀)' is thoroughly confused. Someone had regarded 'Mado' as a neck region of human body, someone had regarded 'Mado' as a lump of neck region, the others had regarded that mean of 'Mado' is 'longish'. So we would like to find out clear mean of 'Maso'. Methods : We have found out examples of 'Mado' from ancient books and recent research. We have used books in the field of acupuncture, moxibustion and surgery(YangYiDaQuan(瘍醫大 全), WaiKeDaCheng(外科大成), HuangDiNeiJingLingShu(黃帝內經靈樞), ZhenJiuDaQuan(鍼灸大全), ZhenJiuDaCheng(鍼灸大成), WaiKeLiLi(外科理例), ZhenJiuWenDui(鍼灸問對), WaiKeQuanShengJi (外科 全生集), etc.). Results & Conclusions : Generally part of speech of 'Mado' is adjective. So 'Mado' plays the role of modifying shape of lump and abscess. In some cases, 'Mado' had used as abbreviation of longish shaped skin disease.

저에너지 집속이온빔리소그라피(FIBL)에 의한 미세패턴 형성 (Micropatterning by Low-Energy Focused ton Beam Lithography(FIBL))

  • 이현용;김민수;정홍배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 추계학술대회 논문집
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    • pp.224-227
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    • 1995
  • The micro-patterning by a Bow energy FIB whish has been conventionally utilized far mask-repairing was investigated. Amorphous Se$\_$75/Gee$\_$25/ resist irradiated by 9[keV]-defocused Ga$\^$+/ ion beam(∼10$\^$15/[ions/$\textrm{cm}^2$]) resulted in increasing the optical absorption, which was also observed also in the film exposed by an optical dose of 4.5${\times}$10$\^$20/[photons/$\textrm{cm}^2$]. The ∼0.3[eV] edge shift for ion-irradiated film was about twice to that obtained for photo-exposed. These large shift could be estimated as due to an increase in disorder from the decrease in the sloop of the Urbach tail. For Ga$\^$+/ FIB irradiation with a relatively low energy, 30[keV] and above the amount of dose of 1.4${\times}$10$\^$16/[ions/$\textrm{cm}^2$], the irradiated region in a-Se$\_$75/Ge$\_$25/ resist was perfectly etched in acid solution for 10[sec], which is relatively a short development time. A contrast was about 2.5. In spite of the relatively low incident energy,∼0.225[$\mu\textrm{m}$] pattern was clearly obtained by the irradiation of a dose 6.5${\times}$10$\^$16/[ions/$\textrm{cm}^2$] and a scan diameter 0.2[$\mu\textrm{m}$], from which excellent results were expected fur incident energies above 50[keV] which was conventionally used in FIBL.

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Application of an Energy Sensitive CZT Detector to a DXA Type of Bone Densitometer

  • Yoon, Je-Woong;Lee, Hyung-Koo;Lee, Heung-Kyu
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.422-424
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    • 2002
  • The accuracy of DXA(Dual Energy X-ray Absorptiometry) highly depends on the detection and separation capability of dual energy X-ray X-ray photons. In addition both of scan time and patient exposure are affected by detection efficiency. A CZT detector with a good energy resolution and high detection efficiency was evaluated for the application of bone densitometry. Its performance was compared to a photomultiplier tube with a NaI(T1) scintillator in terms of energy resolution, detection efficiency and the accuracy of bone mineral density measurement. The comparison study was performed with CZT detector and PM tube using DXA equipments(OSTEO Plus, OSTEO Prima, ISOL Technology). The energy spectrum was acquired using MCA(Multi-Channel Analyzer). The used X-ray energy ranged from 20keV to 86keV. The MCA result of the CZT detector showed a slightly sharper energy spectrum than that of NaI(T1). Detection efficiency of the CZT detector at 59.5keV was 1.4 times better. Remarkably the final results of bone mineral density measurements demonstrate only less than 1% difference. The CZT detector appears to have many benefits for the application of bone densitometry. Its excellent energy resolution can enhance the counting accuracy of dual energy X-ray spectrum. Furthermore its compactness in physical dimension and no cooling requirement will be additional benefits for a more compact and accurate bone densitometer.

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Geant4 코드를 사용한 인체팬텀 선량평가 검증 (Verification of Dose Evaluation of Human Phantom using Geant4 Code)

  • 장은성;최지훈
    • 한국방사선학회논문지
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    • 제14권5호
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    • pp.529-535
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    • 2020
  • Geant4는 C++ 언어사용에서 windows 운영체계와 호환이 가능해져, DICOM이나 소프트웨어를 연계하는 인터페이스 기능이 가능해졌다. 기하학적 고형물에 의해 인체 장기를 나타내는 팬텀은 치료나 진단에서 선량 계획과 같은 의학 용도에 널리 사용된다 방사선 방호 목적을 위해서는 에너지가 몇 keV의 일때 설명의 유효성을 보여주는 것일 여전히 필요하다. 본 연구에서는 Geant4 시뮬레이션을 통해 저 keV부터 고 keV까지 다양하게 에너지를 선택하여 인간 팬텀중 일부분을 선택하여 광자 병렬 평면 필드에서 조사했을 때 그 장기에 대한 방사선량을 구하고 Zankl의 승인된 방법에 의해 얻은 결과에 대해 결과를 비교 검증하고자 한다. 몬테카롤로 코드를 사용하여 장기 선량을 평가하는 것의 중요성은 시뮬레이션의 다양한 묘사 및 특성에 의해 중성자, 양성자, 파온 등과 같은 빔의 여러 가지 유형의 입자와 Gev와 같은 높은 에너지에도 적합하다는 것을 확인하였다.

이온 주입과 기판 온도 효과에 의한 Al-1%Si 박막의 Hillock 형성 특성 (Characteristics of Hillock Formation in the Al-1%Si Film by the Effect of Ion Implantation and Substrate Temperature)

  • 최창억;이용봉;김정호
    • 한국전기전자재료학회논문지
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    • 제27권1호
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    • pp.8-13
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    • 2014
  • As packing density in integrated circuits increases, multilevel metallization process has been widely used. But hillock formed in the bottom layers of aluminum are well known to make interlayer short in multilevel metallization. In this study, the effects of ion implantation to the metal film and deposition temperature on the hillock formation were investigated. The Al-1%Si thin film of $1{\mu}m$ thickness was DC sputtered with substrate ($SiO_2/Si$) temperature of $20^{\circ}C$, $200^{\circ}C$, and $400^{\circ}C$, respectively. Ar ions ($1{\times}10^{15}cm^{-2}$: 150 keV) and B ions ($1{\times}10^{15}cm^{-2}$, 30 keV, 150 keV) were implanted to the Al-Si thin film. The deposited films were evaluated by SEM, surface profiler and resistance measuring system. As a results, Ar implanting to Al-Si film is very effective to reduce hillock size in the metal deposition temperature below than $200^{\circ}C$, and B implanting to an Al-Si film is effective to reduce hillock density in the high temperature deposition conditions around $400^{\circ}C$. Line width less than $3{\mu}m$ was free of hillock after alloying.

-중성자 TOF법에 의한 $^{99}Tc$의 에너지의존 중성자 포획단면적측정- (Measurement of the Energy-Dependent Neutron Capture Cross Section of $^{99}Tc$ by Using the Neutron TOF Method)

  • 윤정란;이상복;이준행;이삼열
    • 한국콘텐츠학회논문지
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    • 제5권5호
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    • pp.133-139
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    • 2005
  • 교토대학 원자로실험소의 46-MeV 전자선형가속구를 이용하여 $^{99}Tc$의 중성자포획단면적을 중성자에너지 0.007 eV에서 47 keV에 걸쳐 중성자 비행시간법을 이용하여 측정을 하였다. 이 중성자포획 결과는 $^{10}B(n,\gamma)$반응의 중성자 반응 단면적에 상대적으로 얻어졌다. 얻어진 결과를 확인하기 위해서 교토대학 원자로실험소의 납감속장치를 이용한 결과를 확인하였다. TOF방법으로 얻어진 결과는 0.0253 eV에서의 결과(20.01 b)에 규격화되었다. 기존의 실험결과들과 평가결과들인 ENDF/B-VI, JENDL-3.2, and JEF-2.2은 본 연구에서 TOF와 납감속장치로 얻어진 결과들과 비교 및 검토하였다.

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