• 제목/요약/키워드: barrier function

검색결과 588건 처리시간 0.029초

Pd-SiC 쇼트키 다이오드의 수소 가스 감지 특성 (A Study on a Palladium-Silicon Garbide Schottky Diode as a Hydrogen Gas Sensor)

  • 이주헌;이영환;김창교;조남인
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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    • pp.858-860
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    • 1998
  • A Pd-SiC Schottky diode for detection of hydrogen gas operating at high temperature was fabricated. Hydrogen-sensing behaviors of Pd-SiC Schottky diode have been analyzed as a function of hydrogen concentration and temperature by I-V and ${\Delta}I$-t methods under steady-state and transient conditions. The effect of hydrogen adsorption on the barrier height was investigated. Analysis of the steady-state kinetics using I-V method confirmed that the atomistic hydrogen adsorption process is responsible for the barrier height change in the diode.

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도로변 방음 수림대 유형별 시뮬레이션 모형개발 및 평가 (Model Development and Appraisal by Visual Simulation about Soundproof Grove Types of Street Side)

  • 김성균;정태영
    • 농촌계획
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    • 제11권2호
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    • pp.59-69
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    • 2005
  • Because of increasing numbers of cars many highways are being constructed lively, and the noise of passing cars has influenced surrounding areas. In consideration of this, some alternatives and researches for soundproof facilities are proceeding, but aesthetic approach hasn't been considered. Therefore, this research is focused on soundproof effects for each types, effectual simulation methods, visual assessment and estimation between the landscape before simulation and the landscape after. Soundproof facilities are divided largely by the soundproof barrier, the soundproof mounding, the soundproof grove. The soundproof grove has three main function. First, leaves and branches absorbs sound vibrations. Second, leaves absorbs sound, and branches obstruct sounds. Third, by means of sounds of shaking leaves, forest can offset noises. This research was proceeded by means of classification of soundproof grove types and investigation of visual simulation methods. We made visual simulation for each types, and estimated the landscape for each types.

Particle-in-Cell Simulation for the Control of Electron Energy Probability & Electron temperature of Dielectric Barrier Discharges at Atmospheric Pressure

  • Lee, Jung-Yel;Song, In-Cheol;Lee, Ho-Jun;Lee, Hae-June
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.528-528
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    • 2012
  • Recently, atmospheric pressure plasmas attract lots of interests for the useful applications such as surface modification and bio-medical treatment. In this study, a particle-in-cell Monte Carlo collision (PIC-MCC) simulation was adopted to investigate the discharge characteristics of a planar micro dielectric barrier discharge (DBD) with a driving frequency from 13.56 MHz to 162.72 MHz and with a gap distance of 80 micrometers. The variation of frequency, in the change in the electron energy probability function (EEPF). Through the relation between the ion trajectories and the frequency, results in the change of EEPFs is achievable with the turning point of frequency mode. Therefore, it is possible to categorize the efficient operation range of DBDs for its applications by controlling the interactions between plasmas and neutral gas for the generation of preferable radicals.

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Atmospheric Pressure Plasma Ashing of Photoresist Using Pin to Plate Dielectric Barrier Discharge

  • Park, Jae-Beom;Oh, Jong-Sik;Yeom, Geun-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.1500-1503
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    • 2009
  • In this paper, we studied about atmospheric pressure remote plasma ashing of photoresist(PR), by using a modified dielectric barrier discharge(DBD). The effect of various gas combinations such as $N_2/O_2$, $N_2/O_2+SF_6$ on the changes PR ashing rate was investigated as a function of power. The maximum PR ashing rate of 1850 nm/min was achieved at $N_2$ (70 slm)/ $O_2$ (200 sccm) + $SF_6$ (3 slm). We found that as the oxygen and fluorine radical peaks were increased, the ashing rate is increased, too.

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염기성 및 산성 약물의 혈액-뇌관문 투과에 관여하는 내인적 수송계 (Role of Endogenous Transport Systems for the Transport of Basic and Acidic Drugs at Blood-Brain Barrier)

  • 강영숙
    • Journal of Pharmaceutical Investigation
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    • 제23권1호
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    • pp.1-9
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    • 1993
  • The endothelial cell of brain capillary called the blood-brain barrier (BBB) has carrier-mediated transport systems for nutrients and drugs. The mechanism of the BBB transport of basic and acidic drugs has been reviewed and examined for endogenous transport systems in BBB in WKY and SHRSP. Acidic drugs such as salicylic acid and basic drugs such as eperisone are taken up in a carrier mediated manner through the BBB via the monocarboxylic acid and amine transport systems. The specific dysfunction for the choline transport at the BBB in SHRSP would affect the function of the brain endothelial cell and brain parenchymal cell. The utilization of the endogenous transport systems of monocarboxylic acid and amine could be promising strategy for the effective drug delivery to the brain.

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Polyimide 터널 장벽을 이용한 Arachidicacid 단분자막의 비탄성 터널 스펙트라 (Inelastic Electron Tunneling Spectroscopy of 1-layer Arachidicacid films using a Polyimide barrier)

  • 이원재;강도열;암본광정
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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    • pp.234-236
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    • 1994
  • We fabricated Au/PI/Pb and Au/PI/1-layer Arachidic acid/Pb structures in order to electron transport properties through the junctions. It was found that 9-layer PI LB films function as a good tunneling barrier from the I-V properties. And several peaks originating in the vibrational modes of the constituent molecules of 1-layer arachidicacid LB films were clearly observed in $d^2V/dI^2-V$ curves.

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국내외 방음벽 관련 연구동향 분석 및 개발 방향 (Analysis of Research Trend and Development Direction on Domestic and International Noise Barriers)

  • 안호상;김일호;박종빈;이주행;김광수
    • 대한환경공학회지
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    • 제34권12호
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    • pp.847-854
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    • 2012
  • 최근 국내 거주지역의 다변화와 고속도로와의 근접성을 고려한 선호되는 위치의 변화로 인해 방음벽에 대한 수요 및 설치에 대한 필요성이 그 어느 때보다 증대되고 있다. 하지만, 방음벽의 설치에도 불구하고, 도로로부터 발생되는 소음에 대한 민원은 지속되고 있는 실정이다. 또한, 이미 설치된 방음벽에서도 황변, 먼지침착, 충격파괴 등의 유지, 보수에 대한 어려움이 제기되고 있다. 이로 인해 위에서 제시된 문제점을 해결하기 위한 방법으로 새로운 소재를 이용 또는 새로운 개념의 방음벽에 대한 연구필요성이 제시되고 있다. 본 연구는 새로운 소재의 개발, 부가기능의 첨가, 또는 설계의 다변화를 통해 기존의 방음벽이 안고 있는 기술적, 경제적 문제점을 해결하기 위한 새로운 방음벽 개발의 첫 단계로 기존의 국내외 방음벽과 관련된 기 수행된 연구동향을 분석하고 이에 따라 향후 개발방향에 대해서 모색하였다.

태반이 피부장벽에 미치는 영향 (The effects of the Hominis placenta on skin barrier)

  • 남혜정;박외숙;김희정;김규석;차재훈;김윤범
    • 한방안이비인후피부과학회지
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    • 제19권2호
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    • pp.99-107
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    • 2006
  • Objectives : This experimental study was performed to investigate the effects of the Hominis placenta extracts on skin barrier. Methods : Male hairless mice, average weight 20g, were divided into two groups, intact and treatment group(paired, n=15). Intact group was not applied YB-301(an ointment including Hominis placenta). Treatment group was applied YB-301(an ointment including Hominis placenta) two times a day for 8 days. We observed skin melanin, skin erythema, skin pH, skin humidity, transepidermal water loss. Statistical analysis was performed by using paired sample T-test. Statistical significance was achieved if the probability was less than 5%(p<0.05) or 1%(p <0.01) Results : 1. YB-301(an ointment including Hominis placenta) showed statistically significant effect on skin melamin, skin pH, skin humidity(p<0.05). 2. YB-301(an ointment including Hominis placenta) showed statistically significant inhibitory effect on transepidermal water loss(p<0.01). 3. YB-301(an ointment including Hominis placenta) showed statistically no significant effect on skin erythema(p<0.05). conclusions : YB-301(an ointment including Hominis placenta) was effective m skin melanin, skin pH, skin humidity, transepidermal water loss in our study, so we suggest that Hominis placenta can be used as a ointment ingredient for strengthening the function of skin barrier.

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삼원계 산화 절연층을 가진 자기터널접합의 자기·구조적 특성에 관한 연구 (Magnetoresistance and Structural Properties of the Magnetic Tunnel Junction with Ternary Oxide Barrier)

  • 박성민;이성래
    • 한국자기학회지
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    • 제15권4호
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    • pp.231-235
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    • 2005
  • Al에 Zr과 Nb 또는 Zr과 Ti을 첨가한 삼원계 산화층을 절연층으로 사용한 자기터널접합(Magnetic Tunnel Junction, MTJ)에서, 각 원소의 비율에 따른 자기적 특성과 절연층의 미세구조 특성을 연구하였다. $(ZrNb)_{0.1}Al_{0.9}$$(ZrTi)_{0.1}Al_{0.9}$ 삼원계 산화 절연층을 가진 자기터널접합의 자기저항비는 Nb, 또는 Ti과 Zr의 첨가 비율이 1 : 1에 가까워질수록 낮아졌으며, Zr과 비교해 Nb 또는 Ti의 첨가량이 많아질수록 자기터널접합의 저항이 감소하였다. 이는 ZrNbAl, ZrTiAl 삼원계 합금 박막은 비정질인 ZrAl 이원계 합금박막과는 달리 다결정체로서 불균일한 산화 절연층을 형성하여 자기저항 및 전기적 특성을 감소시키는 역할을 하기 때문이다. 그러나 삼원계 산화 절연층의 경우 이원계 경우보다 낮은 터널 저항을 특성을 나타내었으며 이는 Nb 또는 Ti이 벤드갭 내에 국부적 에너지 준위를 만들어 에너지 장벽이 감소된 효과로 추측된다.

W-C-N 확산방지막의 격자상수 변화 분석을 통한 특성 연구 (Analysis of Lattice constants change for study of W-C-N Diffusion)

  • 김수인;이창우
    • 한국진공학회지
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    • 제17권2호
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    • pp.109-112
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    • 2008
  • 고집적화된 반도체 소자 기술은 나날이 발전하고 있다. 특히 금속 배선을 위한 박막제조 공정에서 배선 선폭은 감소하고 있으며, 그 길이는 더욱 증가하게 되었다. 이러한 상황에서 금속 배선 물질에 대한 연구가 진행 되었고 그 결과 Cu가 그 대안으로 인식되었다. 하지만 Cu는 저온에서도 Si기판과 반응하므로 인하여 접촉면의 저항이 급격히 증가하여 소자로써의 기능이 불가능하게 되는 단점이 있다. 따라서 이러한 Cu와 Si기판 사이의 반응을 효과적으로 방지할 확산방지막의 개발이 필수 요건이 되었다. 본 연구는 Cu의 확산을 방지하는 W-C-N 확산방지막에 대한 연구로 질소비율과 열처리 온도를 변화하여 실험하였으며, 특히 격자상수 변화를 통하여 W-C-N 확산방지의 특성에 대하여 연구하였다.