• Title/Summary/Keyword: barrier function

Search Result 588, Processing Time 0.025 seconds

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

  • Lee, Joo-Hun;Lee, Young-Hwan;Kim, Chang-Kyo;Cho, Nam-Ihn
    • Proceedings of the KIEE Conference
    • /
    • 1998.11c
    • /
    • pp.858-860
    • /
    • 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.

  • PDF

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

  • Kim, Sung-Kyun;Jeong, Tae-Young
    • Journal of Korean Society of Rural Planning
    • /
    • v.11 no.2 s.27
    • /
    • pp.59-69
    • /
    • 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
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2012.02a
    • /
    • pp.528-528
    • /
    • 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.

  • PDF

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

  • Park, Jae-Beom;Oh, Jong-Sik;Yeom, Geun-Young
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.1500-1503
    • /
    • 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.

  • PDF

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

  • Kang, Young-Sook
    • Journal of Pharmaceutical Investigation
    • /
    • v.23 no.1
    • /
    • pp.1-9
    • /
    • 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.

  • PDF

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

  • Lee, Won-Jae;Kang, Dou-Yol;Iwamoto, Mitsumasa
    • Proceedings of the KIEE Conference
    • /
    • 1994.11a
    • /
    • pp.234-236
    • /
    • 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.

  • PDF

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

  • Ahn, Hosang;Kim, Ilho;Park, Jong-Bin;Lee, Ju Haeng;Kim, Gwang Soo
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.34 no.12
    • /
    • pp.847-854
    • /
    • 2012
  • The demand for noise barriers and necessity for the installation are highly growing because residential areas have become diverse and locational priority is changed to consider how to approach highway easily. However, public annoyance to the noise generated from highway is continued despite lots of noise barrier are installed. Moreover, there are growing concerns to maintain noise barriers to be free from losing transparency, dust stack, and shock fracture. To resolve these issues, it is suggested to develop new polymer materials and conceptually new noise barrier. In this study, as a first step to develop a new noise barrier to overcome current technological challenges as well as economic issues, recent research trends have been analyzed and found the direction for the future research in terms of material, supplementary function, and patterning.

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

  • Nam, Hae-Jung;Park, Owe-Suk;Kim, Hee-Jeong;Kim, Keoo-Seok;Cha, Jae-Hoon;Kim, Yoon-Bum
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
    • /
    • v.19 no.2
    • /
    • pp.99-107
    • /
    • 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.

  • PDF

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

  • Park, Sung-Min;Lee, Seong-Rae
    • Journal of the Korean Magnetics Society
    • /
    • v.15 no.4
    • /
    • pp.231-235
    • /
    • 2005
  • We studied the microstructural evolution of ZrTM-Al (TM=Nb and Ti) alloy films, MR and electrical properties of the MTJ with $ZrTM-AlO_x$ barrier as a function of Zr/TM ratio. We observed that the ternary-oxide barrier reduced the TMR ratio due mainly to the structural defects such as the surface roughness. The change in TMR ratio and $V_h$ with Zr/TM ratio exactly corresponds to the systematic changes in the microstructural variation. Although the MTJ with ternary oxide reduced the TMR and the electrical stabilities, the junction resistances decreased as the Ti and Nb concentration increased due to the band-gap reduction caused by the formation of extra bands

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

  • Kim, Soo-In;Lee, Chang-Woo
    • Journal of the Korean Vacuum Society
    • /
    • v.17 no.2
    • /
    • pp.109-112
    • /
    • 2008
  • The miniaturization of device size and submicron process causes serious problems in conventional metallization due to the solubility of silicon and metal at the interface, such as an increasing contact resistance in the contact hole and interdiffusion between metal and silicon. Moreover, the interaction between Cu and Si is so strong and detrimental to the electrical performance of Si even at temperatures below $200^{\circ}C$. Therefore it is necessary to implement a barrier layer between Cu and Si. So we study W-C-N diffusion barrier for prevent Cu diffusion as a function of $N_2$ gas flow and thermal stability. Especially, we also study the W-C-N diffusion barrier for analyzing the change of lattice constants.