• 제목/요약/키워드: Unit Cell

검색결과 2,061건 처리시간 0.023초

Biomorphic C/SiC 복합재료의 기계적 물성 연구 (Prediction of Mechanical Property of Biomorphic Composites)

  • 정재연;우경식;이동주;홍순형;김연철
    • 한국항공우주학회지
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    • 제40권8호
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    • pp.670-677
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    • 2012
  • 본 논문에서는 Biomorphic C/SiC 복합재료에 대하여 단위구조해석을 수행하였다. 소나무와 뉴송을 탄화하고 실리콘을 함침해 제조한 복합재료의 미세조직을 사각배열과 육각배열로 가정해 단위구조를 정의하고 등가물성치를 계산하였다. 단위구조의 크기가 동일하지 않은 경우도 고려하였고, 또한 공극의 배열에 따른 물성치의 변화를 몬테카를로 시뮬레이션을 통해 조사하였다.

EDLC용 폴리머 겔 전해질 (Polymer Gel Electrolytes for EDLCs)

  • 정세일;정현철;강안수
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2003년도 추계학술대회
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    • pp.351-357
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    • 2003
  • The optimum polymer gel electrolyte composition ratio was 23 : 66 : 11 wt% of P(VdF-co-HFP) : PVP =20 : 3), (PC: EC =44 : 22) and TEABF$_4$. And the optimal thickness of polymer gel electrolyte was 50 ${\mu}{\textrm}{m}$. The electrochemical characteristics result of unit cell were 31.41 Fig of specific capacitance, and 3.21$\times$10$^{-3}$ S/cm of ion conductivity. Ion conductivity of polymer gel electrolytes decreased according to added PVP through impedance analysis, and it was higher in 7 wt%, but electrochemical characteristics of unit cell were better in 3 wt% PVP. And for excellent ion conductivity of polymer gel electrolytes, the use of a thin layer electrolyte(20 $\mu\textrm{m}$) was an effective method, but with unit cell application, the best thickness was 50 $\mu\textrm{m}$. Unit cell showed higher capacitance and more stable electrochemical performance when hot pressed between polymer gel electrolyte and electrode. This results from enhancement of the physical contact between the electrode and the polymer gel electrolyte and good accessibility of the liquid electrolyte to the electrode surface.

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MCFC 의 단위전지 발전특성 (Generation characteristics of unit cell for MCFC)

  • 김귀열;엄승욱;문성인;윤문수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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    • pp.224-226
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    • 1995
  • Molten Carbonate Fuel Cell are expected as an electric and thermal power source of the urban cogenerating system because MCFC have higher electric power efficiency and better thermal power quality. This study has examined generation characteristics of unit cell for MCFC.

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SOFC의 단위전지 특성평가 (Characteristics of Unit Cell for SOFC)

  • 김귀열;엄승욱;문성인
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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    • pp.80-83
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    • 1996
  • Among the fuel cell system, solid oxide fuel eels is constructed of ceramics, so stack construction is simple , power density is very high, and there is no corrosion problems. The purpose of this research is investigate the characteristics of unit cell for SOFC .

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Enantioselective N-Acetylation of 3-Amino-3-phenylpropionic Acid by Cell-free Extracts of Streptomyces neyagawaensis

  • Chung, Myung-Chul;Lee, Ho-Jae;Lee, Choong-Hwan;Chun, Hyo-Kon;Kho, Yung-Hee
    • Journal of Microbiology and Biotechnology
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    • 제7권5호
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    • pp.329-332
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    • 1997
  • Cell-free extracts of Streptomyces neyagawaensis SL-387 grown on a chemically defined medium supplemented with DL-3-amino-3-phenylpropionic acid (APP) produced N-acetyl-APP (Ac-APP) in the presence of APP and acetyl coenzyme A. The APP obtained by acid hydrolysis of the Ac-APP was D-configuration: $[\alpha]_D+6.5^{\circ}(H_2O)\;at\;20^{\circ}C$, optical purity 92% enantiomeric excesses (ee). These results suggest that an N-acetyltransferase exists in the cell-free extract as a novel enzyme with specificity for D-APP.

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A 6-bit 3.3GS/s Current-Steering DAC with Stacked Unit Cell Structure

  • Kim, Si-Nai;Kim, Wan;Lee, Chang-Kyo;Ryu, Seung-Tak
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제12권3호
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    • pp.270-277
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    • 2012
  • This paper presents a new DAC design strategy to achieve a wideband dynamic linearity by increasing the bandwidth of the output impedance. In order to reduce the dominant parasitic capacitance of the conventional matrix structure, all the cells associated with a unit current source and its control are stacked in a single column very closely (stacked unit cell structure). To further reduce the parasitic capacitance, the size of the unit current source is considerably reduced at the sacrifice of matching yield. The degraded matching of the current sources is compensated for by a self-calibration. A prototype 6-bit 3.3-GS/s current-steering full binary DAC was fabricated in a 1P9M 90 nm CMOS process. The DAC shows an SFDR of 36.4 dB at 3.3 GS/s Nyquist input signal. The active area of the DAC occupies only $0.0546mm^2$ (0.21 mm ${\times}$ 0.26 mm).

Sesquicillin, an Extracellular Matrix Adhesion Inhibitor, Inhibits the Invasion of B16 Melanoma Cells In vitro

  • Lee, Ho-Jae;Chun, Hyo-Kon;Chung, Myung-Chul;Lee, Choong-Hwan;Kho, Yung-Hee
    • Journal of Microbiology and Biotechnology
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    • 제9권1호
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    • pp.119-121
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    • 1999
  • Tumor cell interaction with the extracellular matrix is defined as the critical event of tumor invasion that signals the initiation of a metastatic cascade. Sesquicillin has been identified as an inhibitor of melanoma cell adhesion to the components of the extracellular matrix (ECM) in cultured broth of fungal strain F60063. Sesquicillin strongly inhibited the adhesion of B16 melanoma cells to laminin, fibronectin, and typeIV collagen. It also inhibited B16 melanoma cell invasion of reconstituted basement membrane Matrigel in vitro in a dose-dependent manner. These results suggest that sesquicillin is a new class of nonpeptidic ECM adhesion inhibitor having anti-invasive activity.

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초저온 보존된 오이 배발생세포 현탁배양으로부터 식물체 재분화 (Plant Regeneration from Cryopreserved Embryogenic Cell Suspension Cultures of Cucumber)

  • 김석원;인동수;정원중;우제욱;정민;유장렬
    • 식물조직배양학회지
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    • 제25권6호
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    • pp.501-505
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    • 1998
  • 오이의 국내 F1 품종인 조생낙합의 하배축 유래 배발생 현탁배양 세포의 초저온 보존 시스템을 개발하였다. 액체질소 저장 후 캘러스 재생률은 2M DMNSO와 0.4 M sucrose를 혼용 처리하였을 때 캘러스 재생률이 85%로 가장 높았다. 그러나 glycerol 처리구에서는 처리농도에 상관없이 모든 처리구에서 캘러스 재생이 이루어지지 않았다. 또한 고농도의 삼투용액에서 배양세포의 전처리 과정은 필요하지 않았다. 재생된 캘러스를 1 mg/L 2,4-D가 첨가된 MS 배지로 이식하여 배양하였을 때 다수의 체세포배가 발달하였으며, 체세포배를 MS 기본배지로 옮겨 명배양한 결과 다수의 소식물체가 발달하였다.

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Chiral Compound $[C_{24}H_{22}N_4O_4S]_2HCl$로 확인한 결정학적 단위포 변환시의 한 조언 (A Tip for Crystallographic Unit Cell Transformation Verified by a Chiral Compound $[C_{24}H_{22}N_4O_4S]_2HCl$)

  • Suh, Il-Hwan;Kim, Jin-Gyu;Park, Ji-Cheol;Park, Young-Soo;Park, Kyung-Lae
    • 한국결정학회지
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    • 제11권2호
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    • pp.89-94
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    • 2000
  • A crystallographic unit cell can be transformed into another one by a 3×3 transformantion matrix. If the determinant of the transformation matrix has a negative value, the newly transformed unit cell becomes a left-handed cell. The best way of transforming the left-handed cell to the right-handed one is to multiply each element of the transformation matrix by-1, and its corresponding transformation matrix must be applied tot he atomic coordinates of a noncentrosymmetric crystal so as to maintain the absolute configuration unchanged. The behaviour of absolute configuration caused by transforming the crystallographic unit cell was examined theoretically and experimentally on the compound (S)-(+)-4-phenyl-1-[4-aminobenzoyl) indoline-5-sulfonyl]-4,5-dihydro-2-imidazolone hydrochloride.

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