• 제목/요약/키워드: Cd4GeS6

검색결과 7건 처리시간 0.019초

$Cd_{4}GeS_{6}$$Cd_{4}GeS_{6}:Co^{2+}$ 단결정의 성장 (Crystal Growth of Cd4GeS6 and Cd4GeS6:Co2+Single Crystals)

  • 김덕태;김형곤;김남오
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 추계학술대회 논문집
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    • pp.1-6
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    • 2004
  • In this paper author describe the undoped and $Co^{2+}$ (0.5mole%)doped $Cd_4GeS_6$ single crystals were grown by the chemical transporting reaction(CTR) method using high purity(6N) Cd, $GeS_2$, S elements. It was found from the analysis of X-ray diffraction that the undoped and $Co^{2+}$(0.5mole%) doped $Cd_{4}GeS_{6}$ compounds have a monoclinic structure in space grop Cc. The optical energy band gap was direct band gap and temperature dependence of optical energy gap was fitted well to Varshni equation. Impurity optical absorption peaks due to the doped cobalt in the $Cd_4GeS_6:Co^{2+}$ single crystal were observed at 3593cm-1, 5048cm-1, 5901cm-1, 7322cm-1, 12834cm-1, 13250cm-1, 14250cm-1,and 14975cm-1 at 11.3K.

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화학수송법으로 성장한 $Cd_{4}GeSe_{6}$$Cd_{4}GeSe_{6}:Co$ 단결정에서 Energy Gap의 온도의존성 및 열역학함수 추정 (Temperature Dependence of Energy Gap and Thermodynamic Function Properties of Undoped and Co-doped $Cd_{4}GeSe_{6}$ Single Crystals by Chemical Transport Reaction Method)

  • 김덕태;김남오;최영일;김병철;김형곤;현승철;김병인;송찬일
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
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    • pp.31-36
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    • 2002
  • In this work $Cd_{4}GeSe_{6}$ and $Cd_{4}GeSe_{6}:Co^{2+}$ single crystals were grown by the chemical transport reaction method and the structure of $Cd_{4}GeSe_{6}$ and $Cd_{4}GeSe_{6}:Co$ single crystals were monoclinic structure. The temperature dependence of optical energy gap was fitted well to Varshni equation. Also, the entropy, enthalpy and heat capacity were deduced from the temperature dependence of optical energy gap.

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Cobalt를 첨가한 $Cd_4GeS_6$ 단결정에서 Energy Gap의 온도의존성 및 열역학적 함수 추정 (Temperature Dependence of Energy Gap and Thermodynamic Function Properties of Coblt-doped $Cd_4GeS_6$Single Crystals)

  • 김덕태
    • 한국전기전자재료학회논문지
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    • 제11권9호
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    • pp.693-699
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    • 1998
  • In this work $Cd_4GeS_6:Co^{2+}$(0.5mole%) single crystals were grown by the chemical transporting reactiov(CTR) method using high purity(6N) elements. The grown single crystals crystallized in a monoclinic structure(space group Cc). The direct optical energy gap of this single crystals was found to be 2.445eV at 300K and the temperature dependence of optical energy gap was fitted well to Varshni equation. But at temperatures lower than 70K an anomalous temperature dependence of the optical energy gap was obtained. This anomalous temperature dependence accored well with the anomalous temperature dependence of the unit cell volume. Also, the entropy, enthalpy and heat capacity were deduced from the temperature dependence of optical energy gaps.

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Open Source를 이용한 MicroPACS의 구성과 활용 (Application of MicroPACS Using the Open Source)

  • 유연욱;김용근;김영석;원우재;김태성;김석기
    • 핵의학기술
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    • 제13권1호
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    • pp.51-56
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    • 2009
  • 목적 : Small-scalled PACS, Pc-based PACS로 표현되는 MicroPACS 시스템 구축에 대한 관심도가 급격하게 증가하고 있는 추세이다. MicroPACS 시스템은 PACS를 작은 규모에서 사용할 수 있도록 구성해놓은 것이고, 이 시스템을 구성하기 위해서는 DICOM viewer나 연결프로그램 등이 필요하다. 이것은 공개소스프로그램(Open Source Program)을 통해서 어느 누구나 쉽게 무료로 다운로드를 받을 수 있게 되어있다. 본 논문은 Open source program으로 MicroPACS를 직접 구성해보았고, 저장매체로서의 활용가치를 측정하기위하여 성능, 안정성 측면에서 기존의 광 저장매체(CD, DVDRAM)와 비교 분석하였다. 실험재료 및 방법 : 1. 소형 PACS를 구축하기 위해서 먼저 다음 기준에 맞는 DICOM Server Software를 검색한다. (1) 윈도우체제에서 사용가능할 것. (2) Free ware일 것. (3) PET/CT scanner와 호환되어야 할 것. (4) 사용하기 쉬워야 할 것. (5) 저장의 한계가 없어야 할 것. 2. (1) MicroPACS의 성능을 평가하기 위해 환자 1명의 Data ($^{18}F$-FDG Torso PET/CT)를 현재 Back-up장치로 쓰이는 광 저장매체(CD, DVD-RAM)와 MicroPACS에 저장하는데 소요되는 시간(Back up time)과 workstation으로 복구되기까지의 시간(Retrieval time)을 비교해 보았다. (2) PET/CT 검사를 시행했던 환자 1명의 병록번호와 검사 시행날짜를 핵의학과 직원 7명을 대상으로 알려주고 Data를 찾는데 소요되는 시간을 MicroPACS와 광 저장매체(CD, DVD-RAM)에서 각각 측정하여 비교하였다. 3. 기존의 백업장치로 쓰였던 CD들 중에서 2004년부터 2006년까지 500장을 무작위로 뽑아서 loading을 하였고 그중에서 얼마만큼의 에러가 발생하였는지를 측정하여 MicroPACS의 안정성을 비교평가하였다. 결과 : 1. Server와 DICOM viewer 기능을 갖춘 11개의 open source software 중에서 Conquest DICOM Server를 선택하였다. 2. (1) Backup과 Retrieval 시간 비교(단위 : 분)는 다음과 같다; DVD-RAM(5.13,2.26)/Conquest DICOM Server (1.49,1.19) by GE DSTE (p<0.001), CD (6.12,3.61)/Conquest (0.82,2.23) by GE DLS (p<0.001), CD (5.88,3.25)/Conquest (1.05,2.06) by SIEMENS. (2) CD ($156{\pm}46$초), DVD-RAM ($115{\pm}21$초) and Conquest DICOM Server ($13{\pm}6$초). 3. 1년간 MicroPACS에서의 데이터손실은 없었으며(0%), 500장의 CD 중에서 14개(2.8%)가 Loading하는데 실패하였다. 결론 : 현재 많은 병원에서 도입되고 있는 Full PACS를 open source software를 통하여 소규모의 PACS로 재현해 보았고, 그 결과 가능하다는 결론이 나왔다. 데이터 저장의 유용성을 평가한 결과에서 MicroPACS를 이용하는 것이 기존의 광저장매체를 사용하는 것보다 효율적이고 작업속도가 향상 된다는 것을 확인할 수 있다.

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Evaluation of Some Agri-industrial By-products Available in Samoa for Goats

  • Aregheore, E.M.;Abdulrazak, S.A.;Fujihara, T.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권11호
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    • pp.1593-1598
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    • 2003
  • Nutritional evaluation of some agro-industrial byproducts available in Samoa [dry brewers' grains (DBG), cocoa shell (CS), cocoa dust (CD) and desiccated coconut waste meal (DCWM)] available in Samoa was carried out using both the in vivo and in vitro techniques. In the in vivo study 24 Anglo-nubian goats were offered by-products with other feed ingredients to compound four different diets. The goats were randomly allocated to 4 diets on the basis of liveweight (18.7-0.3kg). The ADF content of the byproducts followed a similar trend to NDF. The byproducts have a high content of organic matter (91.0-95.4%). Gross energy (GE) content was higher in DCWM (25.1 MJ/kg DM), closely followed by CD (23.2 MJ/kg DM). Concentrate intake was significantly different (p<0.05) among the goats. Average daily live weight gains were 105, 92, 88 and 97 g/goat/day for DBG, CS, CD and DCWM, respectively. Daily live weight gains were higher (p<0.05) in the goats that received DBG, while the least gain was obtained in the goats that received CS byproduct diet. DM digestibility was significantly higher (p<0.05) in the goats on DBG diet than in the other goats. The least DM digestibility was obtained in the goats that received CD diet (p>0.05). CP digestibility followed a similar pattern to DM digestibility. The digestibility of NDF and ADF was influenced by the nature of the diets. The digestibility of OM and GE were best (p<0.05) in the goats that received DBG, DCWM and CS byproduct diets than in CD. Significant differences (p<0.05) among the byproducts were recorded for net gas production. Potential gas production (a+b) ranged from 7.064 to 42.17 ml. Organic matter digested (OMD) from gas production value at 24 h was higher in DBG (47.6 g/kg DM) and this was followed by DCWM (42.5 g/kg DM). The least OMD was obtained in CD (17.9 g/kg DM). A significant difference (p<0.05) in DM disappearance after 4, 8, 16, 24, 48 and 72 h was recorded. The potential and effective degradability varied significantly (p<0.05) from 85.95-99.6 g/kg DM and from 39.9-65.8%, respectively. The digestibility of the byproducts in both the in vivo and in in vitro techniques demonstrated that they are potential source of feed ingredients for ruminant livestock in Samoa and possibly in the other small Pacific Island countries. On the basis of their potential degradability the byproducts could be ranked in the following order:DCWM>DBG>CD>CS. In conclusion, the results obtained suggest that all the byproducts can contribute to ruminant livestock diets without adverse effects on feed intake, growth rate and apparent nutrient digestibility coefficients.

분광타원해석법을 이용한 $Ge_2Sb_2Te_5$ 의 복소굴절율 결정 (Determination of the complex refractive index of $Ge_2Sb_2Te_5$ using spectroscopic ellipsometry)

  • 김상준;김상열;서훈;박정우;정태희
    • 한국광학회지
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    • 제8권6호
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    • pp.445-449
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    • 1997
  • 비정질상과 결정상으로 가역변화하는 특성을 이용하여, 기존의 읽기전용 기록매체인 Compact Disk(CD)를 대체할 차세대 광기록매체로 주목받고 있는 Ge$_{2}$Sb$_{2}$Te$_{5}$(GST)의 상태변화에 따른 굴절율과 소광계수, 박막의 두께와 밀도 등 박막상수들을 구하였다. DC 스퍼터링방법으로 제작한 두꺼운 GST의 복소굴절율을 양자역학적 분산식을 이용한 모델링방법으로 구하고, 한편으로는 표면미시거칠기를 AFM(Atomic Force Microscopy)으로 결정한 다음, 타원해석 스펙트럼들을 수치해석적 역방계산하여 구한 복소굴절율과 비교하였다. 결정상과 비정질상일 때의 GST의 복소굴절율을 각각 구하고 이로부터 계산된 반사율을 측정된 반사율과 비교함으로써 수치해석적인 방법이 실제 GST의 복소굴절율과 더 일치하는 값ㅇㄹ 가지게 됨을 확인하였다. 이렇게 구한 GST의 복소굴절율을 기준데이터로 사용하여 실제 설계두께를 가지는 GST박막의 두께 및 표면거칠기층을 정량적으로 구하였다.다.

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$Zn_{4}SnSe_{6}$$Zn_{4}SnSe_{6}:Co^{2+}$ 단결정에서 광학적 에너지 띠 및 열역학적 함수의 온도의존성 연구 (Temperature dependence of optical energy gaps and thermodynamic function of $Zn_{4}SnSe_{6}$ and $Zn_{4}SnSe_{6}:Co^{2+}$ single crystals)

  • 김덕태;김남오;최영일;김병철;김형곤;현승철;김병인;송찬일
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
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    • pp.25-30
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    • 2002
  • The ternary semiconducting compounds of the $A_{4}BX_{6}$(A=Cd, Zn, Hg; B=Si, Sn, Ge; X=S, Se, Te) type exhibit strong fluorescence and high photosensitivity in the visible and near infrared ranges, so these are supposed to be materials applicable to photoelectrical devices. These materials were synthesized and single crystals were first grown by Nitsche, who identified the crystal structure of the single crystals. In this paper. author describe the undoped and $Co^{2+}$-doped $Zn_{4}SnSe_{6}$ single crystals were grown by the chemical transport reaction(CTR) method using iodine of $6mg/cm^{3}$ as a transport agent. For the crystal. growth, the temperature gradient of the CTR furnace was kep at $700^{\circ}C$ for the source aone and at $820^{\circ}C$ for the growth zone for 7-days. It was found from the analysis of x-ray diffraction that undoped and $Co^{2+}$-doped $Zn_{4}SnSe_{6}$ compounds have a monoclinic structure. The optical absorption spectra obtained near the fundamental absorption edge showed that these compounds have a direct energy gaps. These temperature dependence of the optical energy gap were closely investigated over the temperature range 10[K]~300[K]

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