• Title/Summary/Keyword: cross-diffusion

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The study of electron transport coefficients in pure Xe by 2-term approximation of the Boltzmann equation (2항근사 볼츠만 방정식을 이용한 Xe분자가스의 전자수송계수의 해석)

  • Ma, Su-Young;Jeon, Byung-Hoon;Kim, Song-Gang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.05c
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    • pp.174-177
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    • 2001
  • The electron transport coefficients, the electron drift velocity W, the longitudinal diffusion coefficient $ND_L$ and $D_L/{\mu}$, in pure Xe were calculated over the wide E/N range from 0.01 to 500 Td at 1 Torr by two-term approximation of the Boltzmann equation for determination of electron collision cross sections set and for quantitative characteristic analysis of Xe molecular gas.

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The study of electron transport coefficients in pure Ne by 2-term approximation of the Boltzmann equation (2항근사 볼츠만 방정식을 이용한 Ne분자가스의 전자수송계수의 해석)

  • Jeon, Byung-Hoon;Gang, Myung-Hee;Kim, Song-Gang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.05c
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    • pp.182-185
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    • 2001
  • The electron transport coefficients, the electron drift velocity W, the longitudinal diffusion coefficient $ND_L$ and $D_L/{\mu}$, in pure Ne were calculated over the wide E/N range from 0.01 to 300 Td at 1 Torr by two-term approximation of the Boltzmann equation for determination of electron collision cross sections set and for quantitative characteristic analysis of Ne molecular gas.

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The study of electron transport coefficients in pure $CO_2$ by 2-term approximation of the Boltzmann equation (2항근사 볼츠만 방정식을 이용한 $CO_2$분자가스의 전자수송계수의 해석)

  • Jeon, Byung-Hoon;Kim, Ji-Yeon;Kim, Song-Gang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.05c
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    • pp.164-167
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    • 2001
  • The electron transport coefficients, the electron drift velocity W, the longitudinal diffusion coefficient $ND_L$ and $D_L/{\mu}$, in pure $CO_2$ were calculated over the wide E/N range from 0.01 to 500 Td at 1 Torr by two-term approximation of the Boltzmann equation for determination of electron collision cross sections set and for quantitative characteristic analysis of $CO_2$ molecular gas. And for propriety of two-term approximation of Boltzmann equation analysis, the calculated results compared with the electron transport coefficients measured by Nakamura.

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A Study on the electron energy diffusion function of the sulphur hexaflouride (SF_6 가스의 전자에너지 분포함수에 관한 연구)

  • ;金相南
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.13 no.2
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    • pp.227-227
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    • 1999
  • The electron energy distributions function were analysed in sulphur hexaflouride at E/N : 500~800(Td) for a case of non-equilibrium region in the mean electron energy. This paper describes the electron transport characteristics in $SF_6$ gas calculated for range of E/N values from 150~800(Td) by the Monte Carlo simulation and Boltzmann equation method using a set of electron collision cross sections determined by the authors and the values of electron swarm parameters. The results gained that the value of ane1ctron swarm parameter such as the e1ectron drift velocity, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients agree with the experimental and theoretical for a range of E/N. The properties of electron avalanches in an electron energy non-equilibrium region.

고집적회로에서 TiN/Ti Diffusion Barrier의 열처리에 따른 계면반응 및 구조변화에 대한 연구

  • Yu, Seong-Yong;Choi, Jin-Seog;Paek, Su-Hyon;Oh, Jae-Eung
    • ETRI Journal
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    • v.13 no.4
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    • pp.58-69
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    • 1991
  • 고집적회로에서 A1 금속공정의 diffusion barrier로 널리 사용되는 titanium nitride의 성질을 조사하였다. 실제 회로 구조의 열적 안정성을 관찰하기 위하여 준비된 TiN/Ti다층 barrier를 $600^{\circ}C$까지 열처리하여 x-ray photoelectron spectroscopy (XPS), cross-sectional transmission electron microscopy(XTEM) 등으로 분석하였다. 열처리 온도가 증가됨에 따라 oxygen은 TiN 층의 표면과 pure-Ti 층에 pile up 된다. TiN 층의 표면에서는 $600^{\circ}C$열처리시 TiN이 분해되어 완전히 $TiO_2$가 형성되며, TiN 층 내에서는 oxygen 함량은 열처리 온도의 증가에 따라 커지고 이때 형성되는 Ti-oxide는 $TiO_2$ 보다 TiO, $Ti_2$$O_3$ 상태로 존재하게 된다. Pure-Ti 층은 열처리시 두개의 층으로 나누어 지는 데, 표면에서 침투하는 oxygen과 pure-Ti이 반응하여 Ti-oxide 층이 생기며 실리콘 기판과의 반응으로 Ti-silicide를 형성한다. $600^{\circ}C$에서 모든 Ti 층이 반응으로 소모되고 열적 stress, Ti-silicide의 grain growth, oxygen의 침입으로 TiN 층에 blistering이 발생한다.

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A study on the development of the high efficiency condensing heat exchanger (고효율 응축형 열교환기 개발에 관한 연구)

  • Lee, Geum-Bae;Park, Sang-Il;Park, Jun-Tae
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.5
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    • pp.589-601
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    • 1997
  • A computer simulation program of a high efficiency condensing heat exchanger is developed. The flue gas flows outside bare tube bundles both in strong cross flow and in weak counter flow and the cooling water inside the tubes. Condensing heat exchangers achieve high efficiency by reducing flue-gas temperatures to a level at which most of the water vapor in the flue gas is condensed and the latent heat associated with phase change of the water is recovered. The computer model has been verified by comparison with measured data. To verify the model, heat transfer coefficient was adjusted, along with the mass transfer diffusion coefficient and pressure drop coefficient, to achieve agreement between predicted and measured data. The efficiencies of heat exchanger increase 2.3 ~ 8.1% by condensations of 6.3 ~ 62.6% of the water vapor in the flue gas.

Micro-Structural Enhancement of XLPE Insulation Using Additive Diffusion Method

  • Park, Se-Eun;Shim, Sung-Ik;Cho, Dae-Hee;Youn, Bok-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.238-239
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    • 2005
  • With the aim of developing XLPE insulation for extra high voltage cable, we investigated the morphology of cross-linked polyethylene. We used a kind of base materials and additives, and controlled curing condition and amount of additives. The effect of addition of additives on morphology of XLPE such as lamellar density, orientation and additive layer were analyzed using TEM analysis. We applied this result to diffused additive amount was analyzed using FT-IR analysis, and the change of microstructure as the degree of additive diffusion was analyzed using TEM analysis.

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Synthesis of Hexagonal Boron Nitride Nanosheet by Diffusion of Ammonia Borane Through Ni Films

  • Lee, Seok-Gyeong;Lee, Gang-Hyeok;Kim, Sang-U
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.252.1-252.1
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    • 2013
  • Hexagonal boron nitride (h-BN) is a two dimensional material which has high band-gap, flatness and inert properties. This properties are used various applications such as dielectric for electronic device, protective coating and ultra violet emitter so on. 1) In this report, we were growing h-BN sheet directly on sapphire 2"wafer. Ammonia borane (H3BNH3) and nickel were deposited on sapphire wafer by evaporate method. We used nickel film as a sub catalyst to make h-BN sheet growth. 2) During annealing process, ammonia borane moved to sapphire surface through the nickel grain boundary. 3) Synthesized h-BN sheet was confirmed by raman spectroscopy (FWHM: ~30cm-1) and layered structure was defined by cross TEM (~10 layer). Also we controlled number of layer by using of different nickel and ammonia borane thickness. This nickel film supported h-BN growth method may propose fully and directly growing on sapphire. And using deposited ammonia borane and nickel films is scalable and controllable the thickness for h-BN layer number controlling.

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Glucose Diffusion Limiting Membrane Based on Polyethyleneimine (PEI) Hydrogel for the Stabilization of Glucose Sensor

  • Kim, Suk-Joon;Shin, Woonsup
    • Journal of Electrochemical Science and Technology
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    • v.12 no.2
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    • pp.225-229
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    • 2021
  • Commercially available continuous glucose sensors require the operation stability for more than two weeks. Typically, the sensor comprises a sensing layer and an over-coating layer for the stable operation inside the body. In the sensing layer, enzymes and mediators are cross-linked together for the effective sensing of the glucose. The over-coating layer limits the flux of glucose and works as a biocompatible layer to the body fluids. Here, we report the simple preparation of the flux-limiting layer by the condensation of polyethyleneimine (PEI), tri-epoxide linker, and trimethylolpropane triglycidyl ether (PTGE). The sensor is constructed by a layer-by-layer drop-coating of the sensing layer containing glucose dehydrogenase and the PEI-derived blocking layer. It is stable for more than 14 days, which is enough for the sensor in the continuous monitor glucose monitoring (CGM) system.

Monte Carlo Simulation of the Electron transport coefficients using Electron collision cross sections for $SP_{6}$ Gas ($SP_{6}$ 가스의 전자충돌단면적을 이용한 전자수송계수에 대한 몬테칼로 시뮬레이션)

  • 서상현;전병훈;하성철
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.11a
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    • pp.152-157
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    • 1995
  • The electron transport coefficients in $SP_{6}$ gas is calculated and analysed for range of E/N values from 150∼800(Td) by a Monte Carlo simulation, using a set of electron collision cross sections determined by the authors. The result of the Monte Carlo simulation such as electron drift velocity, ionization and electron attachment coefficients, longitudinal and transverse diffusion coefficients in neatly agreement with the respective experimental and theoretical for a range of E/N. The validity of the results obtained has been confirmed by a Monte Carlo simulation carried out parallel to the analysis.

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