• 제목/요약/키워드: GaN powder

검색결과 36건 처리시간 0.021초

배합사료에 크릴, 켈프, 마늘 또는 감귤 분말 첨가가 넙치 육성어의 성장, 혈액 성상 및 지방산 조성에 미치는 영향 (Growth Performance, Hematological Parameter and Fatty Acid Composition of Growing Olive Flounder (Paralichthys olivaceus) to Dietary Inclusion of Kelp Meal, Krill Meal, Garlic Powder or Citrus Meal)

  • 서주영;김경덕;손맹현;이상민
    • 한국수산과학회지
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    • 제43권5호
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    • pp.557-561
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    • 2010
  • This feeding experiment was conducted to investigate the effects of dietary inclusion of some additives on growth performance, hematological parameter and fatty acid composition of growing flounder. Triplicate groups of fish (average weight 120 g) were fed one of five diets containing 5% kelp meal (Ke), 10% krill meal (Kr), 1% garlic powder (Ga), 1% citrus meal (Ci) or control diet (Con) without supplementation for 15 weeks. After the feeding experiment, survival was not significantly different among the groups fed the different diets. Weight gain of fish fed the Ci diet was significantly higher than that of fish fed the Kr diet, but not significantly different from Con, Ke and Ga treatments. Feed efficiency and protein efficiency ratio of fish fed the Ga diet were significantly higher than those of fish fed the other diets. Total protein, glucose, GOT, GPT and total cholesterol contents in the plasma were not affected by the dietary additives. Composition of C20:4n-6 in the dorsal muscle of fish fed the Con diet was significantly higher than that of fish fed the other diets. The results of this study suggest that the dietary inclusion of garlic meal at 1% may improve feed utilization of growing flounder.

뜨거운 곁쌓기 법에 의해 성장된 MgGa2Se4 단결정 박막의 열처리 효과 (Effect of Thermal Annealing for MgGa2Se4 Single Crystal Thin Film Grown by Hot Wall Epitaxy)

  • 방진주;김혜정;박향숙;강종욱;홍광준
    • 센서학회지
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    • 제23권1호
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    • pp.51-57
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    • 2014
  • The evaporating materials for $MgGa_2Se_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $MgGa_2Se_4$ compounded polycrystal powder was deposited on thoroughly etched semi-insulated GaAs(100) substrate by the hot wall epitaxy (HWE) method system. The source and substrate temperatures of optimized growth conditions, were $610^{\circ}C$ and $400^{\circ}C$, respectively.The source and substrate temperatures were $610^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by double crystal X-ray diffraction (DCXD). The temperature dependence of the energy band gap of the $MgGa_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=2.34\;eV-(8.81{\times}10^{-4}\;eV/K)T^2/(T+251\;K)$. After the as-grown $MgGa_2Se_4$ single crystal thin films was annealed in Mg-, Se-, and Ga-atmospheres, the origin of point defects of $MgGa_2Se_4$ single crystal thin films has been investigated by the photoluminescence (PL) at 10 K. The native defects of $V_{Mg}$, $V_{Se}$ obtained by PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the Se-atmosphere converted $MgGa_2Se_4$ single crystal thin films to an optical n-type. Also, we confirmed that Ga in $MgGa_2Se_4$/GaAs did not form the native defects because Ga in $MgGa_2Se_4$ single crystal thin films existed in the form of stable bonds.

승검초분말을 첨가한 생면의 품질특성 및 항산화 활성 (Quality characteristics and antioxidant activities of wet noodle added with seunggumcho (Angelica gigas N Leaf) powder)

  • 황현주;박효남;이승주
    • 한국식품과학회지
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    • 제51권2호
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    • pp.120-126
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    • 2019
  • 본 논문에서는 승검초를 동결건조하여 분말을 제조하고 이를 각각 밀가루 중량 대비 1, 2, 3, 4% 첨가한 생면을 제조하였다. 수분함량, pH, 색도, 총 폴리페놀함량, DPPH radical 소거활성, ${\alpha}-glucosidase$ 저해활성의 다각적인 품질특성을 분석하였다. 승검초분말을 첨가한 생면의 조리 후 중량, 부피, 수분흡수율, 탁도는 승검초분말의 첨가량이 증가함에 따라 유의적으로 변화하였다. 조리면의 경도와 탄력성은 승검초분말 첨가량이 증가함에 따라 감소하였다. 총 폴리페놀 함량은 40.53-59.27 mg GA/100 g으로 나타났으며, DPPH 라디칼 저해 활성은 승검초분말 무첨가구에서 10.85%, 첨가량이 증가할수록 15.51, 27.64, 42.48과 44.84%로 증가하여 총 폴리페놀 함량과 양의 상관관계를 보였다. 생면의 ${\alpha}-glucosidase$ 저해활성도 첨가량에 따라 증가하여 혈당 상승 억제 효과를 확인하였다. 또한 조리면의 소비자 기호도 조사를 실시하여 색(color), 향(flavor)과 맛(taste), 쫄깃한 정도(chewiness)를 조사하여 승검초분말 2% 첨가군이 색, 향, 맛, 쫄깃한 정도, 전반적인 기호도에서 가장 높은 점수를 보였다. 본 연구결과 기호도가 높은 첨가군의 최적 배합비율을 제시하고 건강기능성을 포함한 식품으로서 승검초 첨가 생면의 개발 가능성과 승검초를 이용한 다양한 건강식품 개발에 기초자료를 제시하였다.

Tripod Polishing을 이용한 불균질 재료의 TEM 시편준비 방법과 미세조직 관찰 (TEM Sample Preparation of Heterogeneous Materials by Tripod Polishing and Their Microstructures)

  • 김연욱;조명주
    • Applied Microscopy
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    • 제34권2호
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    • pp.95-102
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    • 2004
  • 본 실험에서는 tripod polishing 방법을 이용하여 Pd/GaN/Sapphire 박막, PZT/MgO/Si 박막, 304 stainless steel 분말, $Mo_5Si_3/Mo_2B$ diffusion couple의 매우 다양한 물성이 포함된 불균질 재료의 TEM 시편을 제작하고 분석하였다. Tripod polishing을 사용하여 시편을 준비하면 시편의 종류에 관계없이 시편의 선단부에 매우 광범위한 전자빔 투과 영역을 지닌 TEM 시편을 얻을 수 있었으며, Pd/GaN/Sapphire 박막, PZT/MgO/Si 박막과 같이 기판이 경한 반도체 재료의 경우에는 연마 정도가 균일하며 연마과정 동안 오염이 심하지 않기 때문에 ion milling으로 cleaning 없이 TEM 관찰이 가능하다. 한편 304 stainless steel 분말과 같은 금속재료의 경우 짧은 시간의 ion milling 은 시편의 오염 제거에 도움된다. $Mo_5Si_3/Mo_2B$ diffusion couple에 형성된 실리사이드는 큰 취성 때문에 polishing 동안 시편이 깨지는 현상으로 전자가 투과할 수 있을 정도의 연마가 불가능하여 1시간 정도 ion milling 연마가 필요하다. Tripod polishing으로 TEM 시편을 준비하면 분석하고자 하는 지역을 정확하고도 넓게 연마할 수 있다. 또한 비교적 짧은 시간 내에 ion milling 없이 TEM 시편을 제작할 수 있기 때문에 ion milling에서 유발되는 여러 가지 문제점들을 해결할 수 있는 장점이 있었다. 그러나 tripod polishing은 전부 수작업으로 시편을 준비하기 때문에 시편을 제작하는 과정 동안 매우 세심한 주의가 요구되며 제작자의 숙련도와 경험을 필요로 하는 단점이 있다.

고온 안정성이 우수한 자동차 LED용 Red CaAlSiN3:Eu2+ 형광체/Glass 세라믹 복합체 개발 (Development of Red CaAlSiN3:Eu2+ Phosphor in Glass Ceramic Composite for Automobile LED with High Temperature Stability)

  • 윤창번
    • 한국전기전자재료학회논문지
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    • 제31권5호
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    • pp.324-329
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    • 2018
  • Red phosphor in glasses (PiGs) for automotive light-emitting diode (LED) applications were fabricated with 620-nm $CaAlSiN_3:Eu^{2+}$ phosphor and Pb-free silicate glass. PiGs were synthesized and mounted on high-power blue LED to make a monochromatic red LED. PiGs were simple mixtures of red phosphor and transparent glass powder. After being fabricated with uniaxial press and CIP at 300 MPa for 20 min, the green bodies were thermally treated at $550^{\circ}C$ for 30 min to produce high dense PiGs. As the phosphor content increased, the density of the sintered body decreased and PiGs containing 30% phosphor had a full sintered density. Changes in photoluminescence spectra and color coordination were studied by varying the thickness of plates that were mounted after optical polishing. As a result of the optical spectrum and color coordinates, PiG plate with $210{\mu}m$ thickness showed a color purity of 99.7%. In order to evaluate the thermal stability, the thermal quenching characteristics were measured at temperatures of $30{\sim}150^{\circ}C$. The results showed that the red PIG plates were 30% more thermally stable compared to the AlGaInP red chip.

전력반도체 접합용 천이액상확산접합 기술 (Transient Liquid Phase Diffusion Bonding Technology for Power Semiconductor Packaging)

  • 이정현;정도현;정재필
    • 마이크로전자및패키징학회지
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    • 제25권4호
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    • pp.9-15
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    • 2018
  • This paper shows the principles and characteristics of the transient liquid phase (TLP) bonding technology for power modules packaging. The power module is semiconductor parts that change and manage power entering electronic devices, and demand is increasing due to the advent of the fourth industrial revolution. Higher operation temperatures and increasing current density are important for the performance of power modules. Conventional power modules using Si chip have reached the limit of theoretical performance development. In addition, their efficiency is reduced at high temperature because of the low properties of Si. Therefore, Si is changed to silicon carbide (SiC) and gallium nitride (GaN). Various methods of bonding have been studied, like Ag sintering and Sn-Au solder, to keep up with the development of chips, one of which is TLP bonding. TLP bonding has the advantages in price and junction temperature over other technologies. In this paper, TLP bonding using various materials and methods is introduced. In addition, new TLP technologies that are combined with other technologies such as metal powder mixing and ultrasonic technology are also reviewed.