• Title/Summary/Keyword: Binary Gas Mixtures

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Analysis of Electron Transport Coefficients in Binary Mixtures of TEOS Gas with Kr, Xe, He and Ne Gases for Using in Plasma Assisted Thin-film Deposition

  • Tuan, Do Anh
    • Journal of Electrical Engineering and Technology
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    • v.11 no.2
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    • pp.455-462
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    • 2016
  • The electron transport coefficients in not only pure atoms and molecules but also in the binary gas mixtures are necessary, especially on understanding quantitatively plasma phenomena and ionized gases. Electron transport coefficients (electron drift velocity, density-normalized longitudinal diffusion coefficient, and density-normalized effective ionization coefficient) in binary mixtures of TEOS gas with buffer gases such as Kr, Xe, He, and Ne gases, therefore, was analyzed and calculated by a two-term approximation of the Boltzmann equation in the E/N range (ratio of the electric field E to the neutral number density N) of 0.1 - 1000 Td (1 Td = 10−17 V.cm2). These binary gas mixtures can be considered to use as the silicon sources in many industrial applications depending on mixture ratio and particular application of gas, especially on plasma assisted thin-film deposition.

Pridiction of Adsorption Equilibrium for Binary Gas Mixtures on Cation Exchanged Forms of ZSM-5

  • Going Yim;Chai Suck Yim
    • The Journal of Engineering Research
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    • v.6 no.2
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    • pp.85-98
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    • 2004
  • The adsorption equilibrium data for the binary gas mixture system from the pure gas adsorption data of carbon dioxide and ethylene on ZSM-5 prepared were predicted. The binary gas mixture adsorption data have been examined against predicted values by two models-the vacancy solution model(VSM) and the statistical thermodynamic model(STM), using parameters obtained from the single component isotherm. The binary gas mixture data for the carbon dioxide-ethylene system were obtained for cation exchanged forms of ZSM-5 for the gas phase carbon dioxide mole fraction of 0.752 at $37^{\circ}C$ and 1 atm. The experimental adsorption phase diagrams were obtained for carbon dioxide-ethylene on sodium form ZSM-5 synthesized. The single component adsorption isotherms for carbon dioxide and ethylene were also obtained for this zeolite. The single component data were used to obtain parameters derived in two models. These parameters were, in turn, used to predict the binary mixture isotherms for this zeolite. Both the vacancy solution and the statistical thermodynamic models give satisfactory predictions of adsorption phase diagrams for the binary gas mixtures of carbon dioxide and ethylene on sodium exchanged ZSM-5. Also the correlation between the experimental data and the predicted values is generally in good agreement. The system appears to show ideal behavior with a relatively constant separation factor. The slight increase in adsorption capacity with an increase in ionic radius is due, in part, to the higher polarizability associated with larger cations.

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Binary and ternary gas mixtures of He-Ne-Xe for improvement of vacuum ultraviolet luminous efficiency in ac-PDPs.

  • Jung, Kyu-Bong;Lee, Jun-Ho;Park, Won-Bae;Jeon, Wook;Oh, Phil-Young;Cho, Guang-Sup;Uhm, Han-Sup;Choi, Eun-Ha
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.522-524
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    • 2004
  • The improvement of luminance and luminous efficiency is the one of the most important part in AC-PDPs. To achieve high luminance and luminous efficiency, high VUV emission efficiency is needed. We measured the emission spectra of vacuum ultraviolet(VUV) rays in surface discharge AC-PDP with binary and ternary gas mixtures of Ne-Xe and He-Ne-Xe. The influence of He-Ne-Xe gas-mixture ratio on excited $Xe^{\ast}$ resonant atoms and $Xe_2$$^{\ast}$ dimers has been investigated. It is found that luminous efficiency of ternary gas mixture, He-Ne-Xe, is shown to be much higher than that of binary gas mixture of Ne-Xe.

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The Study of Physical Properties for the Organic Compounds and their Binary Mixture according to Molecular Connectivity Method (Molecular Connectivity法을 이용한 有機化合物과 二成分 混合物에 對한 物理化學的 性質에 關한 硏究 (Ⅱ))

  • Ui-Rak Kim;Kyung-Sub Min;Myung-Jae Lee;Sang-Hae Kim;Bong-Jin Jeong
    • Journal of the Korean Chemical Society
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    • v.36 no.4
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    • pp.485-495
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    • 1992
  • The viscosities of organic compounds (alcohols, acetates, alkanes, acids, substituted $NH_2$) in liquid states, gas states and the binary mixtures of n-alkane / 1-chloroalkane were calculated by molecular modeling techniques. The molecular descriptors of molecular modeling technique are Molecular connectivity indices, Wiener indices and ad hoc descriptors, which can encode the information of compound properties about the effect of size, branching, cyclization, unsaturation, heteroatom content, polarizability, and so on. The successful results among method have been Molecular connectivity indices, binary mixtures of n-alkane / 1-chloroalkane, Wiener indices for gas state and ad hoc descriptor for liquid states. Also we obtained the regression equations for viscosities using molecular modeling indices for gas, liquid states and binary mixtures of n-alkane / 1-chloroalkane. The calculated viscosity values for organic compounds are in good agreement with experimental results.

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Sensing Characterization of Metal Oxide Semiconductor-Based Sensor Arrays for Gas Mixtures in Air

  • Jung-Sik Kim
    • Korean Journal of Materials Research
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    • v.33 no.5
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    • pp.195-204
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    • 2023
  • Micro-electronic gas sensor devices were developed for the detection of carbon monoxide (CO), nitrogen oxides (NOx), ammonia (NH3), and formaldehyde (HCHO), as well as binary mixed-gas systems. Four gas sensing materials for different target gases, Pd-SnO2 for CO, In2O3 for NOx, Ru-WO3 for NH3, and SnO2-ZnO for HCHO, were synthesized using a sol-gel method, and sensor devices were then fabricated using a micro sensor platform. The gas sensing behavior and sensor response to the gas mixture were examined for six mixed gas systems using the experimental data in MEMS gas sensor arrays in sole gases and their mixtures. The gas sensing behavior with the mixed gas system suggests that specific adsorption and selective activation of the adsorption sites might occur in gas mixtures, and allow selectivity for the adsorption of a particular gas. The careful pattern recognition of sensing data obtained by the sensor array made it possible to distinguish a gas species from a gas mixture and to measure its concentration.

Thermal Decomposition Characteristics on Sodium Azide and Metallic Oxide Mixtures (나트륨 아지드와 금속산화물과의 혼합물에 대한 열분해 특성)

  • 이내우;최재욱;박광수;설수덕;왕석주
    • Journal of the Korean Society of Safety
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    • v.12 no.3
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    • pp.106-113
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    • 1997
  • The thermal characteristics of two binary mixtures by sodium azide/manganese dioxide and ferric oxide, two ternary mixtures by sodium azide/silicon dioxide/manganese dioxide and ferric oxide were studied to obtain the basic data of gas-generating agents for air bags. The thermal reaction for all mixtures started at about $420^{\circ}C$, but the temperature at which the reaction rate reached a maximum was different with the states of samples. According to reaction results, nitrogen, nitrogen oxide and nitrogen dioxide were detected by GC-MS and so many kinds of new chemicals from sodium azide and metal oxide mixtures by XRD. NMS is considered as most stable and reasonable mixture for this types of gas-generating agents.

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Breakdown Characteristics of $SF_6/CF_4$ Mixtures under AC Voltages in Uniform, Nonuniform Field (평등, 불평등 전계에서 AC전압의 $SF_6/CF_4$ 혼합가스 절연내력 특성)

  • Sung, Heo-Gyung;Hwang, Cheong-Ho;Kim, Nam-Ryul;Huh, Chang-Su
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1334-1335
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    • 2008
  • Although many studies have been carried out about binary gas mixtures with $SF_6$, few studies were presented about breakdown characteristics of $SF_6/CF_4$ mixtures. At present study the breakdown characteristics of $SF_6/CF_4$ mixtures in uniform and nonuniform field was performed. The experiments were carried out under AC voltages. The sphere-sphere electrode whose gap distance was 1 mm was used and the point-plane electrode whose gap distance was 3 mm was used in a test chamber. $SF_6/CF_4$ mixture contained 20% $SF_6$ and 80% $CF_4$ and the experimental gas pressure ranged from 0.1 to 0.5 MPa. The results show that addition of $SF_6/CF_4$ mixtures increase AC breakdown voltages. In uniform field the breakdown voltages of gas were linearly increased according to the pressure. However in nonuniform field the breakdown voltages of gas were increased nonlinearly.

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Hydrogen Separation from Binary and Quaternary Gas Mixtures Using Organic Templating Silica Membrane (유기템플레이팅 실리카막을 이용한 이성분 및 사성분 수소 분리)

  • Moon, Jong-Ho;Bae, Ji-Han;Chung, Jong-Tae;Lee, Jae-Wook;Lee, Chang-Ha
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.9-12
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    • 2007
  • The transport mechanisms of the MTES (methyltriethoxysilane) templating silica/a-alumina composite membrane were evaluated by using four binary and one quaternary hydrogen mixtures through permeation experiments at unsteady- and steady-states. Since the permeation flux in the MTES membrane, through the experimental and theoretical studies, was affected by molecular sieving effects as well as surface diffusion properties, the kinetic and equilibrium separation should be considered simultaneously according to molecular properties. In order to depict the transient multi-component permeation on the templating silica membrane, the GMS (generalized Maxwell-Stefan) and DGM (dust gas model) were adapted to unsteady-state material balance.

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Analysis of Insulating Characteristics of Cl2-He Mixture Gases in Gas Discharges

  • Tuan, Do Anh
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1734-1737
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    • 2015
  • Insulating characteristics of Cl2-He mixture gases in gas discharges were analysed to evaluate ability of these gases for using in medium voltage and many industries. These are electron transport coefficients, which are the electron drift velocity, density-normalized longitudinal diffusion coefficient, and density-normalized effective ionization coefficient, in Cl2-He mixtures. A two-term approximation of the Boltzmann equation was used to calculate the electron transport coefficients for the first time over a wide range of E/N (ratio of the electric field E to the neutral number density N). The limiting field strength values of E/N, (E/N)lim, for these binary gas mixtures were also derived and compared with those of the pure SF6 gas.

SLI, AC Breakdown Voltage Characteristics of $SF_6/CF_4$ Mixtures Gas in Nonuniform Field (불평등전계에서 $SF_6/CF_4$ 혼합 가스의 SLI, AC 절연내력 특성)

  • Hwang, Cheong-Ho;Sung, Heo-Gyung;Huh, Chang-Su
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.2
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    • pp.245-251
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    • 2008
  • Although many studies have been carried out about binary gas mixtures with $SF_6$, few studies were presented about breakdown characteristics of $SF_6/CF_4$ mixtures. At present study the breakdown characteristics of $SF_6/CF_4$ mixtures in non-uniform field was performed. The experiments were carried out under AC voltage and standard lightning impulse(SLI) voltage. Breakdown characteristics were investigated for $SF_6/CF_4$ mixtures when AC voltages and standard lighting impulse voltage was applied in a needle-plane. The needle-plane electrode whose gap distance was 3 mm were used in a test chamber. $SF_6/CF_4$ mixtures contained from 0 to 100% $SF_6$ and the experimental gas pressure ranged from 0.1 to 0.5 MPa. The breakdown characteristics of $SF_6/CF_4$ mixtures in non-uniform field may be influenced by defects like needle-shaped protrusions. In case of slowly rising SLI voltage and AC voltage it is enhanced by corona-stabilization. This phenomena caused by the ion drift during streamer development and the resulting space-charge is investigated. In non-uniform field under negative SLI voltage the breakdown voltage was increase linearly but under positive SLI voltage the breakdown voltage increase non-linearly. The breakdown voltage in needle-plane electrode displayed N shape characteristics for increasing the content of $SF_6$ at AC voltage. $SF_6/CF_4$ mixture has good dielectric strength and arc-extinguishing properties than pure SF6. This paper presents experimental results on breakdown characteristics for various mixtures of $SF_6/CF_4$ at practical pressures. We could make an environment friendly gas insulation material with maintaining dielectric strength by combing $SF_6\;and\;CF_4$ which generates a lower lever of the global warming effect.