• 한국전기전자재료학회논문지
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• 제31권3호
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• pp.156-159
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• 2018

Inductively coupled plasma (ICP) treatment with argon and a mixture of argon and oxygen gases has been used to modify the surface of polycarbonate (PC) substrates. The results showed that the surface contact angle was inversely proportional to the plasma discharge power and that the mixed-gas plasma (gas flow 10:10 sccm, discharge power 60 W) decreased the surface contact angle as low as $18.3^{\circ}$, indicating a large increase in the surface hydrophilicity. In addition, $SnO_2$ thin films deposited on the PC substrate effectively enhanced the ICP plasma treatment, and could also enhance the usefulness of PC in the inner parts of automobiles.

• 한국안전학회지
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• 제27권5호
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• pp.9-15
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• 2012

The ignition characteristics in a confined axisymmetric coflow $CH_4$ jet were investigated numerically with the Fire Dynamics Simulator(FDS). The $CH_4$ fuel stream was diluted with main combustion product gases, such as $O_2$, $N_2$, CO, $CO_2$, and $H_2O$, and the mixed fuel stream was heated up to the sufficient temperature where a supplying fuel stream can be ignited. For the calculation of chemical reaction in the simulation, a 2-step global finite chemistry model was considered. Boundary condition for confined wall was optimized by investigating the effects of wall temperature on the ignition characteristics of fuel stream. In addition, the effects of composition of diluents in the fuel stream and fuel stream temperature on the ignition of fuel steam were investigated. The ignition characteristics of $CH_4$ stream with diluents were very sensitive to the wall temperature, composition of diluents in the fuel stream and fuel stream temperature.

• 한국디지털건축인테리어학회논문집
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• 제11권4호
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• pp.21-27
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• 2011

These materials in architecturally glass or metal have weaknesses such as inadequate insulating quality, combustibility and toxic gases in fires substance. However, Autoclaved Lightweight Concrete(ALC) has excellent thermal insulation properties and seem to possess the superb insulating quality as substitute of existing exterior materials. This research is to compare experimentally to the kind of the strength properties of ALC materials which mixed with blast furnace slag pounder and silica fume. For the purpose of increasing the strength, the plastic states of ALC evaluate the physical characteristics as microstructure and strength according to various specific gravity. According to the quicklime quantity the compressive strength is proportionate depend on the absolute dried specific gravity. When not putting in 10% quicklime, the compressive strength appeared most lowly with 14.0MPa. When putting in the quicklime, the strength appeared higher with 15.1MPa. And strength of specimen containing 2.25% silica fume is 15.6MPa increased 10.3% than reference specimen 14.0MPa.

• 한국세라믹학회지
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• 제37권2호
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• pp.164-167
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• 2000

Flue gases in the iron foundry consist of 15~20% CO2 as an air pollution gas whose emission should be mitigated in order to protect the environment. In the present study, ultrafine powders of NixZn1-xFe2O4 as a potential catalyst for the CO2 decomposition were prepared by the coprecipitation methods. Oxygen deficient ferrites (MeFe2O4-$\delta$) can decompose CO2 as C and O2 at a low temperature of about 30$0^{\circ}C$. The XRD result of synthesized ferrites showed the spinel structure of ferrites and ICP-AES and EDS quantitative analyses showed the composition similar with initial molar ratios of the mixed solution prior to reaction. The BET surface area of the (Ni, Zn)-ferrites was about 77~89.5$m^2$/g and their particle size was observed about 10~20 nm. The CO2 decomposition efficiency of the oxygen deficient (Nix, Zn1-x)-ferrites was the highest at x=0.3, and the ternary (Ni, Zn)-ferrites was better than that of binary Ni-ferrites.

• 한국분말재료학회지
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• 제17권4호
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• pp.295-301
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• 2010

Multi shell graphite coated Ag nano particles with core/shell structure were successfully synthesized by pulsed wire evaporation (PWE) method. Ar and $CH_4$ (10 vol.%) gases were mixed in chamber, which played a role of carrier gas and reaction gas, respectively. Graphite layers on the surface of silver nano particles were coated indiscretely. However, the graphite layers are detached, when the particles are heated up to $250^{\circ}C$ in the air atmosphere. In contrast, the graphite coated layer was stable under Ar and $N_2$ atmosphere, though the core/shell structured particles were heated up to $800^{\circ}C$. The presence of graphite coated layer prevent agglomeration of nanoparticles during heat treatment. The dispersion stability of the carbon coated Ag nanoparticles was higher than those of pure Ag nanoparticles.

• 한국전기전자재료학회논문지
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• 제16권12S호
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• pp.1232-1236
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• 2003

In this work, we fabricated a gas-sensing device based on porous silicon(PS), and its C-V properties were investigated for sensing alcohol vapor. The structure of the sensor consists of thin Au/oxidized PS/PS/P-Si/Al, where the p-Si is etched anisotropically to be prepared into a membrane-shape. We used alcohol gases vaporized from different alcohol (or ethanol) solutions mixed with pure water at 36$^{\circ}C$, similarly with an alcohol breath measurement to check drunk driving. As the result, I-V curves showed typical tunneling property, and C-V curves were shaped like those of a MIS (metal-insulator-semiconductor) capacitor, where the capacitance in accumulation was increased with alcohol vapor concentration.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 영호남 합동 학술대회 및 춘계학술대회 논문집 센서 박막 기술교육
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• pp.91-95
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• 2006

In whole world consciousness of environment maintenance have increased very quickly for the end of the 20th century. To use and disuse toxic substances have been controled at the field of industry. Also the field of lighting source belong to environmental control. And in the future the control will be strong. In radiational mechanism of fluorescence lamp mechanism is the worst environmental problem. In radiational mechanism of fluorescence lamp mercury is the worst environmental problem root. In the mercury free lighting source system the Xe gas lamp is one type. And the Ne:Xe mixing gas lamp improvements firing voltage of Xe gas lamp. Purpose and subject of this study are understand, efficiency, ideal of Ne:Xe plasma which mercury free lamp. Before ICP was designed, basic parameters of plasma, which are electron temperature and electron density, were measured and calculated by Langmuir probe data. Property of electron temperature and electron density were confirmed by changing ratio of Ne:Xe.

• 대한화학회지
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• 제35권3호
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• pp.204-210
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• 1991

Citrate 공침법으로 합성한 여러가지 perovskite형 복합산화물 흡착제에 대한 질소와 아르곤의 흡착등온곡선을 액체질소 온도에서 BET 중량 흡착장치를 사용하여 측정하였다. 여러 universal adsorption isotherm을 이용하여 흡착층의 통계적 두께 t를 구한 후, 측정한 흡착량을 각각의 통계적 두께 t에 대해서 도시하였다. 이 V-t plot으로부터 얻은 t-method 표면적과 BET 표면적을 비교하였다. 그리고 이 도시 결과에 입각해서 여러 universal adsorption isotherm의 적합성을 고찰하였다.

• 한국재료학회지
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• 제24권3호
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• pp.140-144
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• 2014

The contact mechanism of devices is usually researched at electrode contacts. However, the contact between a dielectric and channel at the MOS structure is more important. The graphene was used as a channel material, and the thin film transistor with MOS structure was prepared to observe the contact mechanism. The graphene was obtained on Cu foil by the thermal decomposition method with $H_2$ and $CH_4$ mixed gases at an ambient annealing temperature of $1000^{\circ}C$ during the deposition for 30 min, and was then transferred onto a $SiO_2/Si$ substrate. The graphene was doped in a nitrogen acidic solution. The chemical properties of graphene were investigated to research the effect of nitric atoms doping. The sheet resistance of graphene decreased after nitrogen acidic doping, and the sheet resistance decreased with an increase in the doping times because of the increment of negative charge carriers. The nitric-atom-doped graphene showed the Ohmic contact at the curve of the drain current and drain voltage, in spite of the Schottky contact of grapnene without doping.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.342-347
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• 2011

Solar energy is attenuated by absorbing gases (ozone, aerosol, water vapour and mixed gas) and cloud in the atmosphere. And these are measured with solar instruments (pyranometer, phyheliometer). However, solar energy is insufficient to represent detailed energy distribution, because the distributions of instruments are limited on spatial. If input data of solar radiation model is accurate, the solar energy reaches at the surface can be calculated accurately. Recently a variety of satellite measurements are available to TERA/AQUA (MODIS), AURA (OMI) and geostationary satellites (GMS-5, GOES-9, MTSAT-1R, MTSAT-2 and COMS). Input data of solar radiation model can be used aerosols and surface albedo of MODIS, total ozone amount of OMI and cloud fraction of meteorological geostationary satellite. The solar energy reaches to the surface is calculated hourly by solar radiation model and those are accumulated monthly and annual. And these results are verified the spatial distribution and validated with ground observations.