• 제목/요약/키워드: Decreasing device

검색결과 231건 처리시간 0.031초

소결공정에 의한 Poly(hydroxypropyl methacrylate) Membrane 제조와 그의 투과특성에 관한 연구 (Preparation of Poly(hydroxypropyl methacrylate) Membraney by Sintering Method and Its Permeation Characteristics)

  • 심정섭;이동권;홍재민
    • 공업화학
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    • 제1권2호
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    • pp.147-153
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    • 1990
  • 소결공정에 의하여 tertiary amine을 함유하는 hydroxypropyl methacrylate 고분자막을 제조하였다. 이 막의 함수율은 수용액의 pH가 감소함에 따라 증가하였다. 인슐린의 투과도 역시 수용액의 pH가 감소함에 따라 증가하였다. 이 막의 투과도는 소결 압력이 증가함에 따라 감소하였다. 이 막에 당산화효소를 고정화시킨 acryl amide 막을 부착하여 복합 matrix device를 제조하였다. 이 막의 인슐린 투과도는 glucose의 농도가 증가함에 따라 증가하였다.

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대응탄 개방형 추진장치용 점화기개발 (Development of Ignitor of Open-Type Propulsion Device for Korean Interceptor)

  • 권순길;김창기;윤상용
    • 한국군사과학기술학회지
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    • 제14권6호
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    • pp.1166-1170
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    • 2011
  • For developing the ignition device for the interceptor of Korean active protection system, the design parameters of the ignition device which should have a short ignition delay time and sufficient energy for propellant ignition were studied. The electric primer instead of mechanical primer was adopted for deceasing delay time, and ignition code was used for decreasing the time difference of flame propagation from the flame holes. The developed ignition device showed the ignition delay time of a few ms. When the designed ignition device was applied to the open-type propulsion devices, the stable interior ballistic characteristic was showed in a firing test.

Large-Eddy Breakup Device가 수중운동체의 저항에 미치는 영향 (Influence of a Large-Eddy Breakup Device on Drag of an Underwater Vehicle)

  • 김준석
    • 한국군사과학기술학회지
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    • 제22권6호
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    • pp.773-783
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    • 2019
  • A numerical analysis of a turbulent flow with a 'large-eddy breakup device(LEBU)' was performed to investigate the influence of the device on the drag of underwater vehicle using commercial CFD code, FLUENT. In the present study, the vehicle drag was decomposed to skin-friction coefficient(Cf) and pressure coefficient(Cp). The variation of the vehicle Cf and Cp were observed with changing location of the device and Reynolds number. As a result, the device decreased the vehicle Cf because it suppressed the turbulent characteristics behind the device. The larger Reynolds number, the higher reduction effect when the device was placed in front part of, and near the vehicle. On the other hand, the device increased/decreased the vehicle Cp with increasing/decreasing turbulent kinetic energy at recirculating flow region behind the vehicle. The total drag change by the device was caused by Cp rather than Cf.

세굴보호장치에 의한 교각주위의 국부세굴 실험 (Experimental Study on Local Scour around Bridge Piers by Scour Protection Devices)

  • 최기봉;김응용
    • 한국안전학회지
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    • 제15권1호
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    • pp.126-131
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    • 2000
  • This study based on the laboratory works, analyzes factors affecting local scour in order to understand various characteristics of the local scour surrounding bridge piers. Attached with scour protection device as a method for decreasing local scour, it carries out the laboratory experiments and calculates the scour depth. From the experiments attached with the scour protection devices, it seems possible to reduce the scour depth as the protecting plate, column and sacrificial piles are built in the same height with flume bed at pier or footing upstream interrupted falling-flow. And then it could reduce scour depth. The paper presents the following research results: First, the decreasing degree of scour depth is in order of protecting column, protecting plate, sacrificial piles and non-protecting facilities. However, it shows no meaningful difference between protecting column and protecting plate. Second, when $L_p/b$=0.5~1, the decreasing effect of scour depth reached the maximum of 40 percents.

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MOD법에 의한 Sr modified $PbTiO_3$ 박막 제조 및 Tunable microwave device 응용 특성 연구 (Sr modified $PbTiO_3$ thin films for tunable microwave device application)

  • 강동헌;조수철;차훈주;조봉희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.749-751
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    • 2002
  • $(Pb_{1-x}Sr_x)TiO_3$ $(0.6{\leq}x{\leq}0.8)$ thin films were prepared by the MOD method for tunable microwave device application and their characteristics were investigated as a function of Sr content(x) and applied field. Thin films showed a homogeneous microstructure and the tetragonality(c/a) was slightly decreased with increasing Sr content. With increasing Sr content, Curie temperature of the thin films showed a decreasing tendency. For the PST thin films, the dielectric constant at room temperature, Tc, and $tan{\delta}$ were 750~1900, $-70^{\circ}{\sim}-30^{\circ}C$ and 0.025~0.04, respectively.

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A Design Evaluation of Strained Si-SiGe on Insulator (SSOI) Based Sub-50 nm nMOSFETs

  • Nawaz, Muhammad;Ostling, Mikael
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제5권2호
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    • pp.136-147
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    • 2005
  • A theoretical design evaluation based on a hydrodynamic transport simulation of strained Si-SiGe on insulator (SSOI) type nMOSFETs is reported. Although, the net performance improvement is quite limited by the short channel effects, simulation results clearly show that the strained Si-SiGe type nMOSFETs are well-suited for gate lengths down to 20 nm. Simulation results show that the improvement in the transconductance with decreasing gate length is limited by the long-range Coulomb scattering. An influence of lateral and vertical diffusion of shallow dopants in the source/drain extension regions on the device performance (i.e., threshold voltage shift, subthreshold slope, current drivability and transconductance) is quantitatively assessed. An optimum layer thickness ($t_{si}$ of 5 and $t_{sg}$ of 10 nm) with shallow Junction depth (5-10 nm) and controlled lateral diffusion with steep doping gradient is needed to realize the sub-50 nm gate strained Si-SiGe type nMOSFETs.

Fabrication Techniques for Carbon Nanotube Field Emitters by Screen Printing

  • Yi, Mann;Jung, Hyuk;Lee, Dong-Gu;Seo, Woo-Suk;Park, Jong-Won;Chun, Hyun-Tae;Koh, Nam-Je
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.655-657
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    • 2002
  • The carbon nanotube emitters for field emission displays were fabricated by screen printing techniques. The pastes for screen printing are composed of organic binders, carbon nanotubes, and some additive materials. Then the pastes were printed on Cr-coated/Ag-printed soda-lime glass substrates. From the I-V characteristics, the turn-on field of SWNT was lower than that of MWNT. The decrease in the mesh size of screen masks resulted in decreasing the turn-on field and increasing the electron emission current. When the carbon nanotubes were mixed with glass frit, glass frit appeared to contribute to the vertically aligning of carbon nanotubes on glass.

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Deep submicrometer PMOSFET의 hot carrier 현상과 소자 노쇠화 (Hot carrier effects and device degradation in deep submicrometer PMOSFET)

  • 장성준;김용택;유종근;박종태;박병국;이종덕
    • 전자공학회논문지A
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    • 제33A권4호
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    • pp.129-135
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    • 1996
  • In this paper, the hot carrier effect and device degradation of deep submicrometer SC-PMOSFETs have been measured and characterized. It has been shown that the substrate current of a 0.15$\mu$m PMOSFET increases with increasing of impact ionization rate, and the impact ionization rate is a function of the gate length and gate bias voltage. Correlation between gate current and substrate current is investigated within the general framework of the lucky-electron. It is found that the impact ionization rate increases, but the device degradation is not serious with decreasing effective channel length. SCIHE is suggested as the possible phusical mechanism for enhanced impact ionization rate and gate current reduction. Considering the hot carrier induced device degradation, it has been found that the maximum supply voltage is about -2.6V for 0.15$\mu$m PMOSFET.

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혼합 발광층을 이용한 백색 전계발광소자의 발광특성 (White Light-Emitting Electroluminescent Device with a Mixed Single Emitting Layer Structure)

  • 김주승;서부완;구할본;조재철;박복기
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
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    • pp.606-609
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    • 1999
  • We fabricated white light-emitting diode which have a mixed single emitting layer containing poly(N-vinylcarbazole), trois(8-hydroxyquinoline)aluminum and poly(3-hexylthiophene) and investigated the emission properties of it. It is possible to obtain a blue light from poly(N-vinylcarbazole). green light from tris(8-hydroxyquinoline)aluminum and red light from poly(3-hexylthiophene). The fabricated device emits white light with slight orange light. We think that the energy transfer in a mixed layer occurred from PVK to Alq₃ and P3HT resulted in decreasing the blue light intensity from PVK. We find that the efficiency of the white light electroluminescent device can be improved by injecting electron more effectively and blue light need to improve the color purity of white light.

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2.2 inch qqVGA AMOLED drived by ultra low temperature poly silicon (ULTPS) TFT direct fabricated below $200^{\circ}C$

  • Kwon, Jang-Yeon;Jung, Ji-Sim;Park, Kyung-Bae;Kim, Jong-Man;Lim, Hyuck;Lee, Sang-Yoon;Kim, Jong-Min;Noguchi, Takashi;Hur, Ji-Ho;Jang, Jin
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.309-313
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    • 2006
  • We demonstrated 2.2inch qqVGA AMOLED display drived by ultra low temperature poly-Si (ULTPS) TFT not transferred but direct fabricated below $200^{\circ}C$. Si channel was crystallized by decreasing impurity concentration even at room temperature. Gate insulator with a breakdown field exceeding 8 MV/cm was realized by Inductively coupled plasma - CVD. In order to reduce stress of plastic, organic film was coated as inter-dielectric and passivation layers. Finally, ULTPS TFT of which mobility is over $20cm^2/Vsec$ was fabricated on transparent plastic substrate and drived OLED display successfully.

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