• 제목/요약/키워드: Film formation

검색결과 1,841건 처리시간 0.035초

가시화를 이용한 가솔린 엔진의 실린더 벽면에서의 연료액막 거동 분석 (Investigation of the Liquid Fuel Film Behavior on the Cylinder Liner in an SI Engine)

  • 조훈;황승환;이종화;민경덕
    • 대한기계학회논문집B
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    • 제27권10호
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    • pp.1370-1376
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    • 2003
  • The investigation of liquid fuel film on the cylinder liner is an essential to understand the engine-out hydrocarbon emissions formation in SI engines. In this research, two-dimensional visualization was carried out to investigate the liquid fuel film on the quartz liner in the optical engine. For this, the optical engine with hydraulic system was designed based on the commercial SI engine. The visualization was based on the laser-induced fluorescence with total reflection technique. Using a quartz liner and a special lens, only the liquid fuel film on the liner was visualized. With using this technique, the distribution of the fuel film on the cylinder liner was measured for different engine conditions and injection timing in the optical engine.

3C-SiC 버퍼층위에 ZnO 박막 형성 (Formation of ZnO ZnO thin films 3C-SiC buffer layer)

  • 이윤명;정귀상
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.237-237
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    • 2009
  • Zinc oxide (ZnO) thin film was deposited on Si substrates using polycrystalline (poly) 3C-SiC buffer layer, in which the ZnO film was grown by sol-gel method. Physical characteristics of the grown ZnO film was investigated experimentally by means of SEM, XRD, FT-IR (Furier Transform-Infrared spectrum), and AFM. XRD pattern was proved that the grown ZnO film on 3C-SiC layers had highly (002) orientation with low FWHM (Full width of half maxium). These results showed that ZnO thin film grown on 3C-SiC buffer layers can be used for various piezoelectric fields and M/NEMS applications.

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리튬 표면의 부동태 피막에 미치는 공용매의 영향 (Effects of Co-solvent on Passivation Film of Lithium Surface)

  • 강지훈;정순기
    • 한국수소및신에너지학회논문집
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    • 제25권3호
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    • pp.305-310
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    • 2014
  • This study examined the morphological changes in lithium surface immersed in 1mol $dm^{-3}$ (M) $LiPF_6 $ dissolved in propylene carbonate (PC) containing different 1,2-dimethoxyethane (DME) concentrations as a co-solvent. A passivation film was formed on the surface of lithium metal by electrolyte decomposition. The passivation film formation reactions were significantly affected by the amount of co-solvent, DME, in electrolyte solution. A stable film was obtained from the 1 M $LiPF_6 $ / PC:DME (67:33) solution in which lithium electrode showed good electrochemical performances. Atomic force microscope (AFM) and electrochemical impedance spectroscopy (EIS) results revealed that there were no direct correlations between changes in the surface morphology of lithium metal and the resistance behavior of its passivation film.

INVESTIGATION OF ENERGETIC DEPOSITION OF Au/Au (001) THIN FILMS BY COMPUTER SIMULATION

  • Zhang, Q. Y.;Pan, Z. Y.;Zhao, G. O.
    • 한국진공학회지
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    • 제7권s1호
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    • pp.183-189
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    • 1998
  • A new computer simulation method for film growth, the kinetic Monte Carlo simulation in combination with the results obtained from molecular dynamics simulation for the transient process induced by deposited atoms, was developed. The behavior of energetic atom in Au/Au(100) thin film deposition was investigated by the method. The atomistic mechanism of energetic atom deposition that led to the smoothness enhancement and the relationship between the role of transient process and film growth mechanism were discussed. We found that energetic atoms cannot affect the film growth mode in layer-by-layer at high temperature. However, at temperature of film growth in 3-dimensional mode and in quasi-two-dimensional mode, energetic atoms can enhance the smoothness of film surface. The enhancement of smoothness is caused by the transient mobility of energetic atoms and the suppression for the formation of 3-dimensional islands.

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단일 액적의 고체 표면 액막과의 충돌 현상에 관한 연구 (A Study on the Phenomena of Droplet Impact onto a Liquid Film)

  • 고천석;유준호;최낙완;강보선
    • 한국분무공학회지
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    • 제18권1호
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    • pp.1-8
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    • 2013
  • In this paper an experimental study is presented to investigate the dynamic behavior of impacting droplet onto a liquid film. The main parameters are the droplet velocity and the thickness of the liquid film. Photographic images are presented to show the formation of crown, central jet and disintegrating droplet from the central jet. The emphasis is on presenting the time evolution of crown diameter, crown height, central jet height and the size of disintegrating droplet from the central jet. The diameter and height of crown are higher for faster droplet and thinner liquid film. On the other hand, the height of central jet are higher for faster droplet and thicker liquid film. The size of disintegrating droplet from the central jet heavily depends on the droplet velocity; Larger droplet is produced with faster falling droplets.

CVD법으로 합성된 알루미나 박막 및 분말의 열처리에 따른 특성 (Properties of the Chemically Vapor Deposited Alumina Thin Film and Powder on Heat Treatment)

  • 최두진;정형진
    • 한국세라믹학회지
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    • 제26권2호
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    • pp.235-241
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    • 1989
  • A study on the APCVD(atmospheric pressure chemical vapor deposition) Al2O3 was done by using the aluminum-tri-isopropoxide/N2 reaction system at 40$0^{\circ}C$. When the flow rate of the carrier gas(N2) was over 2SLPM, heterogeneous reaction was observed. However, when the flow rate of the carrier gas was below 2SLPM, a porously deposited film or powder formation was observed. The film formed by a heterogeneous reaction was optically dense. The dense film is thought to be a kind of a hydrated alumina. After a thermal treatment of the film in the range of temperature from $600^{\circ}C$ to 1, 20$0^{\circ}C$, properties of the film seems to be changed due to dehydration and densification process. In the case of the powder on heat treatment(600~1, 20$0^{\circ}C$), both a phase transformation and the change of OH peak was observed.

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운모기판을 이용한 다결정 Si 전이막 성장 연구 (Growth of Transferable Polycrystalline Si Film on Mica Substrate)

  • 박진우;엄지혜;안병태;정영권
    • 한국재료학회지
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    • 제14권5호
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    • pp.343-347
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    • 2004
  • We investigated the growth feasibility of polycrystalline Si film on mica substrate for the transfer of the layer to a plastic substrate. The annealing temperature was limited up to $600^{\circ}C$ because of crack development in the mica substrate. Amorphous Si film was deposited on mica substrate by PECVD and was crystallized by furnace annealing. During the annealing, bubbles were formed at the Si/mica interface. The bubble formation was avoided by the Ar-plasma treatment before amorphous Si deposition. A uniform and clean polycrystalline Si film was obtained by coating $NiCl_2$ on the amorphous Si film and annealing at $500^{\circ}C$ for 10 h. The conventional Si lithography was possible on the mica substrate and the devices fabricated on the substrate could be transferred to a plastic substrate.