• 제목/요약/키워드: S-47

검색결과 9,217건 처리시간 0.045초

단일 모드 광섬유 표면의 비정질 Chalcogenide 열 증착 (Thermal Evaporation of Amorphous Chalcogenide on Single-mode Optical Fiber)

  • 황성태;조규만;강봉훈;주기태
    • 한국세라믹학회지
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    • 제47권2호
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    • pp.142-145
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    • 2010
  • We made a film of a few ${\mu}m$ thickness by evaporating $As_2S_3$ piece to perpendicularly cut optical fiber by thermal evaporation process. Linear refractive index(n) and linear absorption coefficient(k) of amorphous $As_2S_3$ are 2.525 and $1.727{\times}10^{-3}$, respectively. A surface roughness did not exceed 2 nm and a transmission spectrum showed that the sample of thermal evaporation was homogeneous.

The Black Hole Mass - Stellar Velocity Dispersion Relation of Narrow-Line Seyfert 1 Galaxies

  • 윤요셉;우종학
    • 천문학회보
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    • 제37권1호
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    • pp.47.1-47.1
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    • 2012
  • Given high accretion rates close to the Eddington limit, narrow-line Seyfert 1 galaxies (NLS1) are arguably the most important AGN subclass in investigating the origin of the black hole mass-galaxy stellar velocity dispersion ($M_{BH}-{\sigma}$) relation. Currently, it is highly debated whether NLS1s are offset from the local $M_{BH}-{\sigma}$ relation. The controversy mainly comes from the fact that the [OIII] line width has been used as a proxy for stellar velocity dispersion due to the difficulty of measuring stellar velocity dispersion in NLS1s. Using the SDSS spectra of a sample of 105 NLS1, we performed multi-component fitting analysis to separate stellar absorption lines from strong AGN [FeII] complex in order to directly measure stellar velocity dispersion. We will present the result of decomposition analysis and discuss whether NLS1s follow the same $M_{BH}-{\sigma}$ relation based on the direct measurements of stellar velocity dispersion.

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Cyclobutenediones 에서 Butenolides로의 이색적인 반응 (Unusual Transformation of Cyclobutenediones into Butenolides)

  • 이관희
    • 대한화학회지
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    • 제47권3호
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    • pp.229-236
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    • 2003
  • Cyclobutenedions을 lithium trimethylsilylacetylene과 반응시키고 물로 반응을 정지시키면 butenolides가 생성된다. 이 색다른 반응을 위해 allene을 intermediate로 하는 기전을 제안하였다. 이는 trimethylsilyl group이 너무 크기 때문에 보통의 diradical intermediate는 형성이 어렵고, allene이 ${\alpha}$-silyl group에 의해 안정화되기 때문이라고 사료된다.

Giant Ventral Midline Schwannoma of Cervical Spine : Agonies and Nuances

  • Mahore, Amit;Chagla, Aadil;Goel, Atul
    • Journal of Korean Neurosurgical Society
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    • 제47권6호
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    • pp.454-457
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    • 2010
  • Pure ventral midline giant schwannoma is an extremely rare entity. Spinal intradural extramedullary schwannomas commonly occur posterolateral or anterolateral to the spinal cord. A case of a pure midline ventrally situated giant pan cervical extramedullary schwannoma in an 18-year-old male patient with compressive myelopathy and sphincter involvement is presented. Spinal MR imaging showed a midline ventrally situated extramedullary tumor with severe spinal cord compression extending from clivus to C7 vertebra. It was resected through a posterolateral approach. Histology was consistent with a schwannoma. Post operative MR imaging showed no evidence of the tumor. The radiological features, pathogenesis and surgical strategies in management of these difficult tumors are discussed and the relevant literature is briefly reviewed.

The antioxidant and cytotoxic activities of Sonchus oleraceus L. extracts

  • Yin, Jie;Kwon, Gu-Joong;Wang, Myeong-Hyeon
    • Nutrition Research and Practice
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    • 제1권3호
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    • pp.189-194
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    • 2007
  • This study investigated in vitro antioxidant activity of Sonchus oleraceus L. by extraction solvent, which were examined by reducing power, hydroxyl radical-scavenging activity(HRSA) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assays. 70% MeOH extract had the greatest reducing power while EtOH extract had the greatest HRSA. The antioxidant activity of S. oleraceus extracts was concentration dependent and its $IC_{50}$ values ranged from 47.1 to $210.5\;{\mu}g/ml$ and $IC_{50}$ of 70% MeOH, boiling water and 70% EtOH extracts were 47.1, 52.7 and $56.5\;{\mu}g/ml$, respectively. 70% MeOH extract of S. oleraceus contained the greatest amount of both phenolic and flavonoid contents. The extracts tested had greater nitrite scavenging effects at lower pH conditions. The cytotoxic activity showed that EtOH extract had the best activity against the growth of stomach cancer cell. These results suggest that S. oleraceus extract could be used as a potential source of natural antioxidants.

EFFECTS OF AMMONIATION, IODINATION AND SUPPLEMENTATION OF AVOPARCIN ON THE NUTRITIONAL VALUE OF RAPESEED MEALS

  • Paik, I.K.;Chung, J.S.;An, M.S.;Um, J.S.;Namkung, H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제4권1호
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    • pp.47-57
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    • 1991
  • Supplementation of iodine at the level of 3.5mg/kg reduced weight gain of the rats fed rapeseed oil meal (ROM) diets. Treatment of ROM with ammonia at the level of 2 or 4% tended to increase metabolizable energy value and availability of dry matter, crude protein and crude ash of ROM in the chicken. Potential goitrin level of ROM was reduced by ammoniation at 6% level, while the level of potential isothiocyanates was increased by ammoniation. Treatment of ROM with ammonia at the level of 3% and above reduced weight gain of the chickens fed treated ROMs. Weight of thyroid glands of the birds increased as the level of ammoniation of ROM increased. Supplementation of Avoparcin to the diets containing ROM improved weight gain and dressing percentage of the broiler chickens.

꽃사슴(Formosan deer)의 Hemoglobin형(型)에 관한 연구(硏究) (Studies on the Hemoglobin Phenotype in Formosan Deer (Cervus nippon))

  • 임영재;스즈키 쇼조
    • 대한수의학회지
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    • 제24권1호
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    • pp.31-35
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    • 1984
  • The hemoglobin phenotype and the gene frequencies of 44 Formosan deer(Cervus nippon) in Kyung-Gi area were examined by using cellulose acetate and starch gel electrophoresis. 1. The method of cellulose acetate electrophoresis was simplier, more clear and preserative than starch gel electrophoresis. 2. The hemoglobin phenotype was appeared 3 types as $Hb^F$ $Hb^{FS}$ and $Hb^S$. The frequencies of appearance were $Hb^F$ 47.7%, $Hb^{FS}$ 47.7% and $Hb^S$ 4.5%, respectively. 3. The genetic factors of hemoglobin were observed as $Hb^F$ and $Hb^S$ and the rates of gene frequencies were 71.6% and 28.4%, respectively.

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CrN/AlSiN multilayer coatings의 고온안정성 및 특성에 관한 연구

  • 김영수;김광석;김성민;허용강;이상율
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2008년도 추계학술대회 초록집
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    • pp.47-47
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    • 2008
  • Cr and AlSi (Si=20 and 66 at.%) target들을 이용하여 Closed-field unbalanced magnetron sputtering (CFUBMS)으로 증착된 주기($\Lambda$)가 2.3 nm에서 8.0nm인 CrN/AlSiN multilayer coatings의 crystal structure, 화학적 조성, 및 기계적 특성을 glow discharge optical emission spectroscopy (GDOES), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and nano-indenter 등의 분석장비를 이용하여 분석하였다. 고온안정성을 시험하기 위하여 $800^{\circ}C$$1000^{\circ}C$ 공기중 에서 30분 열처리하였다. CrN/AlSiN multilayer coatings의 고온안정성은 Si조성이 증가함에 따라 향상되었다. Si이 18.2 at.%함유된 coating이 가장 우수한 고온안정성을 갖고 있다.

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누전차단기 하우징의 내후성에 관한 연구 (A Study on the Weathering of RCD'S Housing)

  • 김창환;신진용;강병철;김상명
    • 한국표면공학회지
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    • 제47권6호
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    • pp.335-340
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    • 2014
  • This study selected an outdoor RCD'S and verified behavior of change in the housing with time. Weathering tests were carried out as outdoor exposure test (90 degrees, 37 degrees) and laboratory test (xenon lamp), and the results were evaluated based on color difference, gloss, contact angle, and optical microscope. This study can provide basic data for standardization of development and performance evaluation on RCD'S housing products.

New protocol for simplified reduction and fixation of subcondylar fractures of the mandible: a technical note

  • Kamat, Saurabh Mohandas;Dhupar, Vikas;Akkara, Francis
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제47권5호
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    • pp.403-406
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    • 2021
  • The dilemma regarding the management of condylar fractures generally revolves around the surgical approach, implant design, and the surgeon's experience. Zide and Kent's guidelines streamlined the decision making process for condylar fractures. However, there exists no standardized protocol for reduction and fixation of condylar fractures. Here, we have described a detailed and stepwise protocol, common to any surgical approach, that would lead to predictable, reproducible, and repeatable results in every surgeon's hands.