• Title/Summary/Keyword: Ga-67

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Effects of Phytohromones on Biosynthesis of Phospholipids and Their Fatty Acid Compositions in Chlorella ellipsoidea Chloroplast (Chlorella ellipsoidea 엽록체의 인지질 생합성 및 지방산 조성에 미치는 식물호르몬의 효과)

  • 나형심
    • Journal of Plant Biology
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    • v.35 no.4
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    • pp.371-383
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    • 1992
  • The effects of IAA $(10^{-3}M)\;an;GA_3\;(2{\times}10^{-8}\;M)$ on the biosynthesis of phospholipids and their fatty acid compositions in chloroplast isolated from Chlorella ellipsidea were analyzed. Growth ratio and the levels of total lipids and phospholipids in whole cell system and chloroplast treated with phytohormones were higher than those of control, and when treated with GAl. phosphatidylcholine content was predominantly higher than that of control. It was showed that in whole cell system the fatty acid utilized for biosynthesis of phopholipids was 27.43% for palmitic acid in control, while that was 20.25% for linolenic acid in treatment with 1M. In treatment with $GA_3$, 23.17% for linolenic acid was used in phospholipid formation. The major fatty acid in the chloroplst system was analyzed to be 35.67% for palmitic acid in control and in treatment with 1M, 24.91% for linolenic acid was used in phospholipid formation, while in treatment with $GA_3$, major fatty acid of phospholipids was 22.80% for linoleic acid.c acid.

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Optical Properties of InP/InGaP Quantum Structures Grown by a Migration Enhanced Epitaxy with Different Growth Cycles

  • Oh, Jae Won;Cho, Il-Wook;Ryu, Mee-Yi;Song, Jin Dong
    • Applied Science and Convergence Technology
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    • v.24 no.3
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    • pp.67-71
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    • 2015
  • InP/InGaP quantum structures (QSs) were grown on GaAs (001) substrates by a migration-enhanced molecular beam epitaxy method. Temperature-dependent photoluminescence (PL) and emission wavelength-dependent time-resolved PL (TRPL) were performed to investigate the optical properties of InP/InGaP QSs as a function of migration enhanced epitaxy (MEE) growth cycles from 2 to 8. One cycle for the growth of InP QS consists of 2-s In and 2-s P supply with an interruption time of 10 s after each source supply. As the MEE growth cycle increases from 2 to 8, the PL peak is redshifted and exhibited different (larger, comparable, or smaller) bandgap shrinkages with increasing temperature compared to that of bulk InP. The PL decay becomes faster with increasing MEE cycles while the PL decay time increases with increasing emission wavelength. These PL and TRPL results are attributed to the different QS density and size/shape caused by the MEE repetition cycles. Therefore, the size and density of InP QSs can be controlled by changing the MEE growth cycles.

Power Supply for USN by Using SMD Type Solar Cell Array (SMD 타입 태양전지 어레이를 이용한 USN용 전원 공급 장치)

  • Kim, Seong-Il
    • New & Renewable Energy
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    • v.5 no.3
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    • pp.22-25
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    • 2009
  • For increasing the output voltage, six SMD(surface mount device) type AlGaAs/GaAs solar cells were connected in series. The electrical properties of the array were measured and compared with one sun (100 mW/$cm^2$) and indoor light (480 lux) conditions. Under one sun condition, output power was 21.57 mW and it was $14.67\;{\mu}W$ under indoor light condition. Under the indoor light condition, the intensity of the light is very low compared to one sun condition. Thus the Voc(open circuit voltage) and Isc (short circuit current) of the sample under indoor light condition decreased very much compared to that of under the one sun condition. This kind of solar cell power supply can be used as a power source for ubiquitous sensor network (USN).

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GaAs/A1GaAs HEMT구조의 2DEC 측정

  • Lee, Jae-Jin;Maeng, Seong-Jae;Park, Hyo-Hun;Kim, Jin-Seop;Ma, Dong-Seong
    • ETRI Journal
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    • v.11 no.4
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    • pp.67-74
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    • 1989
  • n-GaAs/A1GaAs계의 화합물 반도체 접합에 형성되는 이차원 전자 가스를 캐패시턴스-전압(C-V), 각도 의존 자기저항(SdH), 전자 빔 반사(EBER)등의 측정 방법을 통하여 A1GaAs 조성비(x)는 0.281, 전도대와 가전도대의 밴드 불연속은 각각 밴드 갭($E_g$)의 69%와 31%임을 알았고, 여기에 존재하는 이차원 전자가스의 면농도는 $5.4\times10^11cm^-2, 페르미 준위 $E_F$는 25mev임을 알았다. 또한 도핑 된 A1GaAs층에서 흔히 나타나는 Franz-Keldysh진동은 불순물의 활성화도가 작으면 형성되는 전기장의 약화로 나타나지 않는다는 것을 발견하였다.

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Characterization of $Cu(In_xGa_{1-x})Se_2$ Solar Cells with Ga Content (Ga 함량에 따른 $Cu(In_xGa_{1-x})Se_2$ 태양전지의 특성분석)

  • Kim, Seok-Ki;Kwon, Se-Han;Lee, Doo-Yeol;Lee, Jeong-Churl;Kang, Ki-Whan;Yoon, Kyung-Hoon;Ahn, Byung-Tae;Song, Jin-Soo
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1264-1267
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    • 1998
  • $Cu(In_xGa_{1-x})Se_2$ thin films were prepared and characterized with various Ga contents. As the Ga content increased, the grain size of CIGS film became smaller. The 2 $\theta$ values in XRD patterns were shifted to larger values and the overlapped peaks were splitted. The energy bandgap increased from 1.04 to 1.67 eV and the resistivity decreased. The solar cell fabricated with ZnO/CdS/$Cu(In_{0.7}Ga_{0.3})Se_2/Mo$ structure yielded an efficeincy of 14.48% with an acitive area of 0.18 $cm^2$. The efficiency decreased with further increase of Ga content.

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Properties of HVPE prepared GaN substrates (HVPE법으로 제작한 GaN 기판의 특성)

  • 김선태;문동찬
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.67-70
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    • 1998
  • In this work, the freestanding GaN single crystalline substrates without cracks were grown by hydride vapor phase epitaxy (HVPE). The GaN substrates, having a current maximum size of 350 $\mu\textrm{m}$-thickness and 10${\times}$10 $\textrm{mm}^2$ area, were obtained by HVPE growth GaN on sapphire substrate and subsequent mechanical removal of the sapphire substrate. A lattice constant of c$\_$0/=5.18486 ${\AA}$ and a FWHM of DCXRD was 650 arcsec for the single crystalline freestanding GaN substrate. The low temperature PL spectrum consist of excitonic emission and deep donor to acceptor pair recombination at 1.8 eV. The Raman E$_2$ (high) mode frequency was 567 cm$\^$-1/ which was the same as that of strain free bulk single crystals. The Hall mobility and carrier concentration was 283 $\textrm{cm}^2$/V$.$sec and 1.1${\times}$10$\^$18/ cm$\^$-3/, respectively. The freestanding and crack-free GaN single crystalline substrate suitable for the homoepitaxial growth of GaN, and the HVPE method are promising approaches for the preparation of large area, crack-free GaN substrates.

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Analysis of Trends and Contents of Ancestral Ritual Foods of Korean Jong-ga - Focus on Domestic Thesis - (한국 종가 제례음식 논문의 내용과 동향분석 - 국내 학술지를 중심으로 -)

  • Lee, Changhyeon;Kim, Young;Hwang, Young;Kim, Hyeonmi
    • Journal of the Korean Society of Food Culture
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    • v.31 no.4
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    • pp.286-299
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    • 2016
  • This study analyzed trends and contents of ancestral ritual foods of Korean traditional Jong-ga as a domestic thesis. In searching the keywords related to ancestral ritual foods using a thesis search site, a total of 15 theses in seven journals were selected for analysis. Three theses from 1996 to 1999, six theses from 2005 to 2008, and another six theses from 2012 to 2016 were announced. In measuring frequency by dividing case families analyzed in the thesis into region, there were 83 families, including seven families from Gyeonggi (8.4%), seven families from Chungcheong (8.4%), two families from Honam (2.4%), and 67 families from Yeongnam (80.8%). Fifty-four families out of 67 families from Yeongnam were located in Andong-si, occupying 65.1% of the 83 families. The family showing the highest frequency was 'Seoae Jong-ga' (12 times). The family clan with the highest frequency was eight families of the 'Jinseong Lee clan' In the future, it would be necessary to understand the research flow through analysis of research trends in ancestral ritual foods of Jong-ga as well as interdisciplinary research and methodological diversification of studies on ancestral ritual foods of Jong-ga.

A femtosecond Cr:LiSAF laser pumped by semiconductor lasers (반도체 레이저 여기 펨토초 Cr:LiSAF 레이저)

  • 박종대
    • Korean Journal of Optics and Photonics
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    • v.11 no.5
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    • pp.360-364
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    • 2000
  • We demonstrate self-starting passIve mode locking of a Cr:LiSAF laser, using a SCIDlconduclor Saturable Absorber Mirror (SESAM), Two high-power red semiconductor lasers (Coherent S-67-500C-100-H) of wavelength 667 nm and maximum power of 500 mW were used as pump lasers, The cavity has 10 cm radius-ai-curvature folding minors, two SF 10 prisms, a 99% reflectivity output coupler and a SESAM at dIe focus of a 10 cm radIus-at-curvature mirror. We used the laser crystal in BrewsterBrewster shape with 1 5% $Cr^{+3}$ ion concentration and the length of 6 mm, An X-shaped resonator was used to compensate the astigmatism induced by tile crystal. The structure of the SESAM cOllSists of 30 pmr of $AlAs/Al_{0.15}Ga_{0.85}As$ layer, wi1l1 a 10 nm GaAs quantum well situated in the topmost layer Output spectra were centeled at 833 nm, with 4 nm spectral bandwidth and pulse width was measured to be 220 fs, Output power of 3 mW is obtained at a pump power of 800 mW. 00 mW.

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