• Title/Summary/Keyword: Dip-Coating

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The effect of the initial BSCCO 2212 grain size on the final grain size and the formation of BSCCO 2223

  • Yoo, Jai-Moo;Park, Myoung-Je;Kim, Hai-Doo;Chung, Hyung-Sik;Ko, Jae-Woong
    • 한국초전도학회:학술대회논문집
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    • v.10
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    • pp.285-288
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    • 2000
  • The effect of the initial BSCCO 2212 grain size on the final gain size and the formation of the BSCCO 2223 was studied using a powder precursor synthesized by two-powder method. 2212 and CaCuO$_2$ tapes were prepared by dip coating and joined by pressing and then followed by the repeated thermo mechanical treatment. The samples were characterized by XRD and SEM analysis. The formation and grain size of the BSCCO 2223 depended on the initial BSCCO 2212 grain size.

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Sloshing Flow of Highly-Viscous Fluid in a Rectangular Box (사각용기에서 발생하는 고점성 유체의 슬로싱 유동)

  • park, Jun Sang
    • Journal of the Korean Society of Visualization
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    • v.17 no.3
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    • pp.39-45
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    • 2019
  • A study on the sloshing flow of highly-viscous fluid in a rectangular box was made by both of theoretical approach and experimental visualization method. Assuming a smallness of external forcing to oscillate the container, it was investigated a linear sloshing flow of highly-viscous fluid utilizing asymptotic analysis by Taylor-series expansion as a small parameter Re (≪1) in which Re denotes Reynolds number. The theory predict that, during all cycles of sloshing, a linear shape of free surface will prevail in a bulk zone and it has confirmed in experiment. The relevance of perfect slip boundary condition, adopted in theoretical approach, to the bulk zone flow at the container wall was tested in experiment. It is found that quasi-steady coated thin film, which makes a lubricant layer between bulk flow and solid wall, is generated on the wall and the film makes a role to perfect slip boundary condition.

Effect of Film Thickness on the Tribological Characteristics of Zdol Lubricant on Silicon Surface

  • Kim, Yong-Sik;Yang, Ji-Chul;Kim, Dae-Eun
    • International Journal of Precision Engineering and Manufacturing
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    • v.5 no.1
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    • pp.13-18
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    • 2004
  • In precision mechanical components that experience sliding, it is important to reduce the friction to minimize surface damage. Particularly, new lubrication methods are needed to reduce friction in silicon based micro-systems applications. In this work, the tribological characteristics of PFPE (Perfluoropolyether) Zdol lubricant on silicon were investigated based on the thickness of the film. The lubricant was coated on silicon wafer specimens by the dip coating method. It was shown that the friction coefficient as well as stiction decreased as the thickness of the film increased. The results of this work may be applied to improve the tribological performance of silicon based micro-system components.

Fabrication of Solid Oxide Fuel Cells by Decalcomanie Methode (전사법을 이용한 고체산화물 연료전지 셀 제조)

  • An, YongTae;Choi, ByungHyun;Ji, MiJung;Gu, JaBin;Shin, SangHo;Hwang, HaeJin
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.83.1-83.1
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    • 2011
  • 고체산화물 연료전지는 전해질의 양쪽에 cathode층과 anode층으로 구성되어 있다. 이러한 셀을 제작하기 위한 구성소재 코팅법으로는 EVD, CVD, sputter등의 기상공정과 screen printing, tape casting, dip coating등의 습식공정이 있다. 이중 현재 가장 널리 사용되고 있는 screen printing법은 코팅기판의 크기와 형태에 제한을 받아 원통형, 평관형에는 적용이 어렵다. 이러한 문제점을 해결하기 위해 본 연구에서는 electrolyte 지지체 위에 전사법을 통해 연료극(NiO-YSZ), 공기극(LSCF-GDC) 코팅층의 두께 및 형상을 제어할 수 있었으며 button cell을 제작하여 실제 SOFC에 적용이 가능함을 확인하였다.

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Development of 590MPa Grade Galvannealed TRIP Steel Sheets containing Low Silicon Contents for High Strength and Formability (차량구조용 고강도 고성형성 590MPa급 Si 저감형 변태유기소성 합금화 용융아연 도금강판의 개발)

  • Chi, Kwang-Sub;Kim, Yong-Hee;Kim, Byoung-Il
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.6
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    • pp.141-147
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    • 2008
  • Hot-dip galvannealed sheet (GA) with high strength of 590MPa grade in tensile strength, has developed for automotive applications. However, for a successful application, the microstructure and galvannealing behavior of galvannealed TRIP steel sheets must be strictly controlled. High silicon contents steel has problems with weld-ability, zinc coating and reduction of retained austenite volume fraction after galvannealing process. The main purpose of this study is to solve the problem as indicated above.

Photoelectrochemical Properties of TiO2 Electrode Prepared by the Sol-Gel Method (Sol-Gel법으로 제조된 TiO2 전극의 광전기 화학적 특성)

  • 김진희;이재훈;설용건;이태희
    • Journal of Energy Engineering
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    • v.3 no.1
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    • pp.36-43
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    • 1994
  • 광전기화학전지의 전극으로 TiO2 반도체 전극을 선택하여, sol 용액을 dip-coating 방법으로 티타늄 금속위에 입혀 만든 TiO2 필름의 광전기화학특성을 연구하였다. Dipping 횟수와 TiO2 필름의 두께간에는 선형적인 비례관계가 나타났으며, 15회 코팅하여 얻은 5.5$\mu\textrm{m}$에서 가장 큰 광전류값을 얻을 수 있었다. 전극의 최종열처리를 50$0^{\circ}C$에서 20분간 행하였을 때 광전류값이 가장 컸고, 열처리시간을 증가시키고, 열처리 온도가 50$0^{\circ}C$ 이상이 되면 광전류는 감소하였다. 유기첨가제로 HPC를 사용한 경우 sol 용액의 점도 및 제조된 전극의 광전류값이 가장 크게 나타났다.

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A study on the electrophotographic properties of ${\tau}-H_2P_c$/oxadiazole photoreceptor (III) (${\tau}-H_2P_c$/oxadiazole 유기이층막의 감광특성 연구 (III))

  • Oh, S.H.;Park, J.K.;Shin, T.H.;Kim, Y.J.;Park, G.B.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1397-1399
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    • 1994
  • The purpose of this study is to measure the electrophotographic characteristics of double-layered organic photoreceptor made by dip-coating method, and to evaluate an application for the laser beam printer drum. From the result, electrophotographic characteristics of the photoreceptor were depend on the thickness of the CTL and the initial surface potential.

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Fabricatoin and electrochemical property of 3-dimesional $LiMn_2O_4$ thin film (3차원 구조의 $LiMn_2O_4$ 박막전극의 제조 및 전기화학적 특성)

  • Park, Bo-Gun;Ryu, Jea-Hyeok;Park, Yong-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.64-65
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    • 2008
  • 3D microbattery에 사용할 수 있는 $LiMn_2O_4$ 3차원 박막전극을 제조하여 그 전기화학적 특성을 관찰하였다. 3차원 구조의 형성을 위하여 먼저 polystyrene(PS) microsphere를 platinum이 증착된 Si/$SiO_2$ 기판위에 dip-coating 방식으로 코팅시켜 template로 사용하였다. 그 위에 sol-gel법을 이용, 박막을 형성시킨 후 template 를 제거하는 방식으로 $LiMn_2O_4$ 3차원 박막전극을 형성하였는데 이때 solution은 Lithium acetylacetonate[$LiCH_3CO-CHCOCH_3$], Manganese(III) acetylacetonate [Mn$(CH_3COCHCOCH_3)_3$]를 source 물질로 1-butanol과 acetic acid를 solvent로 활용하여 제조하였다.

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Fabrication of 3-Dimensional LiMn2O4 Thin Film

  • Park, Bo-Gun;Ryu, Jea Hyeok;Choi, Won Youl;Park, Yong-Joon
    • Bulletin of the Korean Chemical Society
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    • v.30 no.3
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    • pp.653-656
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    • 2009
  • 3-Dimensionally ordered macroporous $LiMn_2O_4$ thin film was prepared by a sol-gel and dip coating method on Pt/Ti/$SiO_2$/Si substrate. An opal structure consisting of mono dispersed polystyrene beads (300 nm) was used as a template. After solution containing Mn and Li precursors was coated on the template-deposited substrate, the template and organic materials in the precursors was removed by calcination at 400 ${^{\circ}C}$. And then the 3-dimensional $LiMn_2O_4$ thin film with spinel structure was fabricated by heat treatment at 700 ${^{\circ}C}$. The structural and electrochemical property was investigated by XRD, SEM and charge-discharge cycler.

Structural Characteristics of Barium Ferrite Thin Film (바륨페라이트 박막의 구조적 특성)

  • Byeon, Tae-Bong;Kim, Tae-Uk
    • Korean Journal of Materials Research
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    • v.7 no.5
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    • pp.423-430
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    • 1997
  • 졸-겔 dip coating법에 의해 제조한 바륨페라이트 박막의 미세구조와 결정학적인 구조 특성에 관해 조사하였다. 기판에 형성된 바륨페라이트 입자는 침상 형태의 입자들로 구성되어 있었으며, C축은 장축 방향이었고, 막 두께가 증가함에 따라 침상형 입자들은 기판에 평행하게 배향하는 경향을 나타내었다. 박막은 바륨페라이트층, Ba, Fe, SiO$_{2}$로 구성되어 있는 중간층, 그리고 기판층인 SiO$_{2}$층으로 구성되어 있었으며, 중간층과 SiO$_{2}$층간의 계면은 Ba 와 SiO$_{2}$간의 화합물로 구성되어 있었다. 침상 형태의 입자는 95$0^{\circ}C$에서 3시간 열처리하므로써 완전히 소실하였고, 130$0^{\circ}C$에서 3시간 열처리하므로써 c면이 기판에 평행하게 위치하는 완전한 육각판상 형태의 입자로 변화되었다.

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