• 제목/요약/키워드: Ga-67

검색결과 256건 처리시간 0.028초

갈륨 신티그라피와 자기공명영상으로 진단한 근육 유육종증 (A Case of Muscular Sarcoidosis diagnosed by Gallium-67 Scintigraphy and Magnetic Resonance Imaging)

  • 손형선;김의녕
    • 대한핵의학회지
    • /
    • 제33권6호
    • /
    • pp.543-547
    • /
    • 1999
  • Gallium-67 scintigraphy is helpful in the assessment of active extrapulmonary sarcoidosis. Muscular involvement of sarcoidosis is often asymptomatic or nonspecific, and laboratory examinations do not provide convincing evidence of muscular involvement We report a case of muscular sarcoidosis, which was detected by gallium-67 scintigraphy. In a patient who was suffering from fever and arthralgia of knee joint, gallium-67 scintigraphy showed mediastinal and hilar involvement of sarcoidosis with unexpected extensive muscular uptake. Magenetic resonance imaging revealed the detailed depiction of intramuscular infiltration of sarcoid granuloma. Gallium-67 scintigraphy is useful in detecting inflammatory muscular involvement of sarcoidosis as well as other multiorgan involvement.

  • PDF

MOCVD로 성장한 Zn-doped InGaN의 광특성 연구 (Optical properties of Zn-doped InGaN grown by MOCVD)

  • 이창명;이주인;임재영;신은주;김선운;서준호;박근섭;이동한
    • 한국진공학회지
    • /
    • 제10권1호
    • /
    • pp.67-71
    • /
    • 2001
  • MOCVD법으로 성장한 Zn-doped InGaN의 광학적 특성을 photoluminescence를 사용하여 연구하였다. 상온에서 Zn와 관련한 acceptor-like conte들에 대한 넓은 스펙트럼들은 2.81 eV와 2.60 eV에서 관측되었다. 특히, 2.81 eV영역에서는 포논과의 상호작용에 의한 스펙트럼이 나타났으며, 포논 에너지가 $\omega$=92.5 meV의 값을 가짐을 확인하였다. InGaN 시료의 온도 변화에 대한 스펙트럼에서, 온도가 증가함에 따라 청색 발광을 기준으로 낮은 쪽의 에너지에 비해 높은 에너지 쪽의 발광이 빠른 감소를 가져왔으며 아울러 2.81eV 영역에 해당하는 스펙트럼은 18meV만큼 높은 에너지 쪽으로 이동함을 관측하였다. 그러므로 청색 영역에서의 발광은 Zn와 관련된 complex conte체서의 국소화된 천이에 따른 결과이다.

  • PDF

Fabrication of AlGaN-based vertical light-emitting diodes

  • Bae, Seon Min;Jeon, Hunsoo;Lee, Gang Seok;Jung, Se-Gyo;Kim, Kyoung Hwa;Yi, Sam Nyung;Yang, Min;Ahn, Hyung Soo;Yu, Young Moon;Kim, Suck-Whan;Cheon, Seong Hak;Ha, Hong-Ju;Sawaki, Nobuhiko
    • Journal of Ceramic Processing Research
    • /
    • 제13권spc1호
    • /
    • pp.75-77
    • /
    • 2012
  • The AlGaN-based vertical light-emitting diodes (LEDs) on thick GaN epilayer were fabricated by a hydride vapor phase epitaxy with multi sliding boat system. The optical and electrical characteristics of AlGaN-based vertical LEDs were evaluated using a scanning electron microscopy, electroluminescence and I-V measurements. The AlGaN-based vertical LEDs structure has hexagonal symmetry, 500 ㎛ in diameter and above 67 ㎛ in growth thickness. At the room-temperature, the broaded strong peak and relatively high intensity peak were gradually measured at 405 nm with increasing injection current. And a forward operator voltage was measured to be about 7.5 V.

Si이 첨가된 $Al_{0.33}Ga_{0.67}As$에서의 Electroreflectance에 관한 연구 (A Study on Electroreflectance in Si-Doped $Al_{0.33}Ga_{0.67}As$)

  • 김근형;김동렬;김종수;김인수;배인호;한병국
    • E2M - 전기 전자와 첨단 소재
    • /
    • 제10권7호
    • /
    • pp.692-699
    • /
    • 1997
  • The silicon doped $Al_{0.33}$G $a_{0.67}$As were grown by molecular beam epitaxy. The electroreflectance(ER) spectra of Schottky barrier Au/n-Al/suu x/G $a_{1-x}$ As have been measured at various modulation voltage( $V_{ac}$ ) and dc bias voltage( $V_{bias}$). From the observed Franz-Keldysh oscillations(FKO) peak, the band gap energy of the $Al_{x}$G $a_{1-x}$ As is 1.91 eV which corresponds to an Al composition of 33%. The internal electric field( $E_{i}$)of this sample is 2.96$\times$10$^{5}$ V/cm. As the modulation voltage( $V_{ac}$ ) is changed, the line shape of ER signal does not change but its amplitude varies linearly. The amplitude as a function of modulation voltage has saturated at 0.8 V. The internal electric field has decreased from 6.47$\times$10$^{5}$ V/cm to 2.00$\times$10$^{5}$ V/cm as the dc bias voltage( $V_{bias}$) increases from -3.5 V to +0.8 V. The values of built-in voltage( $V_{bi}$ ) and carrier concentration(N) determined from the plot of $V_{bias}$ from the plot of $V_{bias}$ versus $E_{i}$$^{2}$ are 0.855 V and 3.83$\times$10$^{17}$ c $m^{-3}$ , respectively.ively.y.y.y.

  • PDF

MgGa$_2$Se$_4$신반도체 단결정을 사용한 광전도도 소자 제작에 관한 연구 (A Study on the Photoconductive Cell Production of New Semiconductor Using MgGa$_2$Se$_4$Single Crystals)

  • 김형곤;김형윤;이광석;이기형
    • 한국통신학회논문지
    • /
    • 제17권1호
    • /
    • pp.58-67
    • /
    • 1992
  • MgGa2Se4 및 MgGa2Se4 : Co2+단결정을 bridgman 방법으로 성장하여 광흡수와 광발광을 가시광 영역과 근적외선 영역에서 조사하였다. 광흡수 스펙트럼은 MgGa2Se4단결정의 Td Symmetry를 갖는 host lattice에 점유하여 바닥상태와 여기상태의 Co2+ ion 에너지 ㅣlevel간 전자전이에 의해서 760nm, 1640nm, 그리고 2500nm에서 3개의 흡수피크를 관측하였다. 광발광 스펙트럼에서 이 단결정은 가시광 발광ㄸ들을 관찰하였다.가시영역의 발광 band들은 에너지 준위도에서 제안된 바와 같이 자전자대의 우의 꼭대기 acceptor 준위에서 전도대 아래의 밑에 분포된 trap으로부터 끊임없이 전자전에 의한다고 볼수 있다. 한편, 이들은 적외선 발광 band가 deep level에서 acceptor level부터 전자전이에 기인한다고 고려할 수 있다. 광전이의 mechanism은 MgGa2Se4 결정의 에너지 diagram의 항으로 잘 설명되고 있다.

  • PDF

"동무선사사상약성상험고가(東武先師四象藥性嘗驗古歌)"의 연원(淵源)과 의의(意義)에 대한 연구(硏究) (A Study on the ${\ulcorner}$DongMuSunSaSaSangYakSungSangHumGoGa${\lrcorner}$'s Origin and Meaning)

  • 박성식
    • 사상체질의학회지
    • /
    • 제14권2호
    • /
    • pp.1-9
    • /
    • 2002
  • I think that the study on the ${\ulcorner}$DongMuSunSaSaSangYakSungSangHumGoGa${\lrcorner}$ of ${\ulcorner}$DongMuYooGo${\lrcorner}$ is basic material explaining the character of sasang-herb and prescription. Through the study on the ${\ulcorner}$DongMuSunSaSaSangYakSungSangHumGoGa${\lrcorner}$'s origin and meaning, I can take the result as follows. The first, that is composed of total 237 herbs of 90 spleen-herb (Soeumin-herb), 61 kidney-herb (Soyangin-herb), 67 lung-herb (Taeeumin-herb) and 19 liver-herb (Taeyangin-herb). The second, the origin of that is ${\ulcorner}$JeJungSinPyun${\lrcorner}$, ${\ulcorner}$BangYakHapPyun${\lrcorner}$ and ${\ulcorner}$EuiHakIpMum${\lrcorner}$. And DongMu classified traditional YakSungGa as spleen-herb, kidney-herb, lung-herb and liver-herb which is suitable to Sasangin, not created that. So we can know that the first understanding for DongMu' s herb is focused on the traditional YakSungGa. The third, DongMu's unique terminology of spleen-herb, kidney-herb, lung-herb and liver herb show his sight of symptom, disease and pharmacology, that is focused on small JangBu. The forth, through herb-nature gathered from traditional YakSungGa, that purposed to classfying each constitutional herb. So we can know his idea that the choice of herb is not in general efficacy but in personal constitution. As mentioned abovet, that can refer to an herbal argument of DongMu and ${\ulcorner}$DongMuYooGoYakSungGa${\lrcorner}$ that make known to be common can refer to an prescriptional argument of DongMu.

  • PDF

마그네슘이 도핑된 GaN 공간층과 양자장벽층을 이용한 무분극 GaN 발광다이오드의 전기적/광학적 특성 향상 (Improvement of Electrical/optical Characteristics Using Mg-doped GaN Spacers and Quantum Barriers for Nonpolar GaN light-emitting Diodes)

  • 김동호;손성훈;김태근
    • 대한전자공학회논문지SD
    • /
    • 제48권7호
    • /
    • pp.10-16
    • /
    • 2011
  • 본 논문에서는 고효율 고출력 무분극 GaN LED의 구현을 위하여 Mg이 도핑된 GaN spacer층 및 GaN quantum barrier(QB)층을 삽입한 구조를 제안하였다. 제안한 구조에 대한 물리적 해석을 위하여 일반적인 무분극 LED 에피구조와 본 연구에서 제안한 p-GaN spacer층 및 p-GaN QB층이 삽입된 무분극 LED 에피구조에 대해 상용화된 $SimuLED^{TM}$ 시뮬레이터를 이용하여 전기적/광학적 특성을 비교 분석하였다. 실험 결과, 본 연구에서 제안한 무분극 LED는 20 mA의 전류주입 하에서 동작전압($V_f$)이 일반적인 무분극 LED에 비해 약 3.7% 감소된 3.67 V의 전기적 특성을 갖는 것을 확인하였고, 광출력은 약 7% 향상된 2.13 mW의 광학적 특성을 갖는 구조임을 확인하였다. 또한, 내부양자효율(Internal quantum efficiency, IQE)과 광방출세기(emission peak intensity) 역시 각각 9.1% 및 170% 향상된 우수한 특성을 갖는 에피구조임을 확인하였다.

A new model approach to predict the unloading rock slope displacement behavior based on monitoring data

  • Jiang, Ting;Shen, Zhenzhong;Yang, Meng;Xu, Liqun;Gan, Lei;Cui, Xinbo
    • Structural Engineering and Mechanics
    • /
    • 제67권2호
    • /
    • pp.105-113
    • /
    • 2018
  • To improve the prediction accuracy of the strong-unloading rock slope performance and obtain the range of variation in the slope displacement, a new displacement time-series prediction model is proposed, called the fuzzy information granulation (FIG)-genetic algorithm (GA)-back propagation neural network (BPNN) model. Initially, a displacement time series is selected as the training samples of the prediction model on the basis of an analysis of the causes of the change in the slope behavior. Then, FIG is executed to partition the series and obtain the characteristic parameters of every partition. Furthermore, the later characteristic parameters are predicted by inputting the earlier characteristic parameters into the GA-BPNN model, where a GA is used to optimize the initial weights and thresholds of the BPNN; in the process, the numbers of input layer nodes, hidden layer nodes, and output layer nodes are determined by a trial method. Finally, the prediction model is evaluated by comparing the measured and predicted values. The model is applied to predict the displacement time series of a strong-unloading rock slope in a hydropower station. The engineering case shows that the FIG-GA-BPNN model can obtain more accurate predicted results and has high engineering application value.