• 제목/요약/키워드: protective film

검색결과 259건 처리시간 0.027초

변류기(p-CT)를 적용한 YBCO 초전도 저항형 한류기의 ?치 특성 (Quench Behaviors of Superconducting YBCO film for Fault Current Limiters applying Protective Current Transformer)

  • 박권배;이방욱;강종성;오일성;현옥배
    • Progress in Superconductivity
    • /
    • 제5권2호
    • /
    • pp.128-131
    • /
    • 2004
  • The resistive superconducting fault current limiters (SFCLs) are very attractive devices for the electric power network. But they have some serious problems when the YBCO thin films were used for the current limiting materials due to the in homogeneities caused by manufacturing process. When the YBCO films have some inhomogeneities, simultaneous quenches are difficult to achieve when the fault current limiting units are connected in series for increasing operating voltage ratings. Magnetic field application is one of the prospective way of inducing simultaneous quenches far the series-connected resistive FCL components. Magnetic field was typically generated by the fault current thorough a coil, which is connected to components of the fault current limiter in series, leaving the problem, which provides significant inductance to the power line and suppresses critical current density of the superconducting components. In this article we investigated the possible application of the protective current transformer (p-CT), which is available current source to the magnetic coil. This system inductively coupled to the circuit, therefore, remarkably reducing impedance to the circuit. The current by the protective current transformer was directly fed to the coil, generating magnetic field large enough to reduce critical current density of the components. This successfully induced simultaneous quenches of the series-connected resistive FCL components.

  • PDF

A Study on the Fluoro-polymer Composite Coatings for Protecting the Corrosion of Fossil-fuel Power Plants

  • Kang, Min Soo;Lee, Byung Seung;Chang, Hyun Young;Jin, Tae Eun;So, Il Soo
    • Corrosion Science and Technology
    • /
    • 제6권2호
    • /
    • pp.62-67
    • /
    • 2007
  • Several heavy duty coatings at an every kind industry facilities to various systems currently have been applied review to the many industry fields. Corrosion-protective characteristics in the case of novolac epoxy among them and unsaturated polyester have been applied most widely. epoxy and flake heavy duty coatings are applied for such reason in an every kind facilities(stack, FGD, cooler, chemical tank etc) of a fossil-fuel power plants Cases of the fossil-fuel power plants are exposed to more severe corrosion environment compared with other facilities and It is difficult to display the performance of long-term method at apply to be the partial. Our study shows fluoro-polymer composite coating method to overcome of the limit. The comparison did previous method and heavy duty coating about FGD plants most at a corrosion environment among fossil-fuel power plants. Additionally, other facilities examined different heavy duty method. The design mode of fluoro-polymer composite coating according to an every kind facilities show extensive methods that are characteristic revelation of film(top, middle and primer layer) composition of the paint, film thickness in accordance with a facilities corrosion and the corrosion protective effectiveness to come into being use fluoro-polymer composite with heavy duty paint(epoxy).

평판 유리로 봉인된 다층 무기 박막을 갖는 OLED 봉지 방법 (Encapsulation Method of OLED with Inorganic Multi-layered Thin Films Sealed with Flat Glass)

  • 박민경;주성후;양재웅;백경갑
    • 한국전기전자재료학회논문지
    • /
    • 제24권11호
    • /
    • pp.905-910
    • /
    • 2011
  • To study encapsulation method for large-area organic light emitting diodes (OLEDs), red emitting OLEDs were fabricated, on which LiF and Al were deposited as inorganic protective films. And then the OLED was attached to flat glass by printing method using epoxy. In case of direct coating of epoxy onto OLED by printing method, luminance and current efficiency were remarkably decreased because of the damage to the OLED by epoxy. In case of depositing LiF and Al as inorganic protective films and then coating of epoxy onto OLED, luminance and current efficiency were not changed. OLED lifetime was more increased through inorganic protective films between OLED and flat glass than that without any encapsulation (8.8 h), i.e., 47 (LiF/Al/epoxy/glass), 62 (LiF/Al/LiF/epoxy/glass), and 84 h (LiF/Al/Al/epoxy/glass). The characteristics of OLED encapsulated with inorganic protective films (attached to flat glass) showed the possibility of application of protective films.

미끄럼운동을 하는 면에 윤활 조건에 따라 발생하는 보호막의 형성과 파괴에 관한 연구

  • 이영재
    • 한국윤활학회:학술대회논문집
    • /
    • 한국윤활학회 1990년도 제12회 학술강연회초록집
    • /
    • pp.16-35
    • /
    • 1990
  • The mechanism of failure of lubricated surfaces at high sliding speeds was Investigated. Experiments were performed with the ball-on-flat and cylinder-on-flat geometries, using lubricants of four different chemical reactivities. Surface failure was found to not be predictable using the ratlo, $\lambda$, of fluid film thickness to composite surface roughness except when chemically inert lubricants are used. Even then the influence of temperature rise on fluid film thickness does not adequately explain the low load carrying capacity of lubricants at high sliding speeds. which causes surface failure. The protective layers on sliding surfaces that form by chemical reaction with the lubricant were found to reduce the surface roughentrig and Increase the load carrying capacity of surfaces to values of $\lambda$ as low as 0.03. Neither the surface toughening nor the formation of the protective layers have been incorporated Into failure models for lubricated systems.

  • PDF

Changes in the electrochemical properties of air-formed oxide film-covered AZ31 Mg alloy in aqueous solutions containing various anions

  • Fazal, Basit Raza;Moon, Sungmo
    • 한국표면공학회:학술대회논문집
    • /
    • 한국표면공학회 2017년도 춘계학술대회 논문집
    • /
    • pp.96.2-96.2
    • /
    • 2017
  • This research was conducted to investigate the electrochemical properties of the thin air-formed oxide film-covered AZ31 Mg alloy. In this work, native air-formed oxide films on AZ31 Mg alloy samples were prepared by knife-abrading method and the changes in the electrochemical properties of the air-formed oxide film were investigated in seven different electrolytes containing the following anions $Cl^-$, $F^-$, $SO{_4}^{2-}$, $NO_3{^-}$, $CH_3COO^-$, $CO{_3}^{2-}$ and $PO{_4}^{3-}$. It was observed from open circuit potential (OCP) transients that the potential initially decreased before gradually increasing again in the solutions containing only $CO{_3}^{2-}$ or $PO{_4}^{3-}$ ions, indicating the dissolution or transformation of the native air-formed oxide film into new more protective surface films. The Nyquist plots obtained from electrochemical impedance spectroscopy (EIS) showed that there was growth of new surface films with immersion time on the air-formed oxide film-covered specimens in all the electrolytes; the least resistive surface films were formed in fluoride and sulphate baths whereas the most protective film was formed in phosphate bath. The potentiodynamic polarization curves illustrated that passive behaviour of AZ31 Mg alloy under anodic polarization appears only in $CO{_3}^{2-}$ or $PO{_4}^{3-}$ ions containing solutions and at more than $-0.4V_{Ag/AgCl}$ in $F^-$ ion containing solution.

  • PDF

프랑스의 신인감독 지원 정책 (Support of CNC for French Young Film Makers)

  • 김이석
    • 한국콘텐츠학회:학술대회논문집
    • /
    • 한국콘텐츠학회 2005년도 춘계 종합학술대회 논문집
    • /
    • pp.208-214
    • /
    • 2005
  • 프랑스는 문화영역에서 강력한 보호정책을 채택하고 있는 국가 중 하나다. '문화적 다양성' 혹은 '문화적 예외'라는 원칙을 내걸고 프랑스는 미국의 '세계화' 정책에 맞서고 있다. 시청각 콘텐츠 영역에서도 마찬가지로 프랑스는 헐리우드 영화의 침범에 맞서 자신의 영화적 영역을 보호하기 위해 보호정책을 채택하고 있다. 프랑스 정부의 다양한 지원 가운데서, 특히 우리는 신인감독에 대한 지원체계와 이 체계 안에서 CNC의 역할에 패해 주목한다. 따라서 이글에서는 정부기관으로서 CNC가 어떻게 프랑스의 시청각영역에 대해 영향력을 행사하는지를 살펴보고, 어떤 과정을 통해 신인감독들의 작업에 실질적인 지원을 제공하는 지를 살펴볼 것이다.

  • PDF

Corrosion Protection of Plasma-Polymerized Cyclohexane Films Deposited on Copper

  • Park, Z.T.;Lee, J.H.;Choi, Y.S.;Ahn, S.H.;Kim, J.G.;Cho, S.H.;Boo, J.H.
    • 한국표면공학회지
    • /
    • 제36권1호
    • /
    • pp.74-78
    • /
    • 2003
  • The corrosion failure of electronic devices has been a major reliability concern lately. This failure is an ongoing concern because of miniaturization of integrated circuits (IC) and the increased use of polymers in electronic packaging. Recently, plasma-polymerized cyclohexane films were considered as a possible candidate for a interlayer dielectric for multilever metallization of ultra large scale integrated (ULSI) semiconductor devices. In this paper the protective ability of above films as a function of deposition temperature and RF power in an 3.5 wt.% NaCl solution were examined by polarization measurement. The film was characterized by FTIR spectroscopy and contact angle measurement. The protective efficiency of the film increased with increasing deposition temperature and RF power, which induced the higher degree of cross-linking and hydrophobicity of the films.

보호필름용 자외선경화형 점착제 (UV-cured Pressure Sensitive Adhesive for Protective Film Application)

  • ;이명천
    • 접착 및 계면
    • /
    • 제18권3호
    • /
    • pp.134-140
    • /
    • 2017
  • 본 연구에서는 포호필름 코팅 용도를 목적으로 silicone-urethaneacrylate (SUA) 올리고머를 포함하는 자외선 경화형 점착제를 제조하였으며 SUA올리고머의 양과 자외선조사량이 접착물성에 미치는 영향을 조사하였다. 그 결과, 올리고머의 양과 자외선조사량이 증가 할 수 록 박리강도는 감소하였으나 응집력은 증가하였다. 자외선 조사가 시작되면서 젤함량은 초기에 급속히 증가하였으나 이후 일정량을 유지하였다. 탈착시험 결과 70%의 올리고머 함량의 시편 S70이 다른 S50(올리고머 50%함량)과 S60(올리고머 60%함량)과 비교하여 가장 우수한 탈착성을 보였으며 탈착 후 기재에 아무런 잔사를 남기지 않았다. S70의 경우 1857 자외선 조사량과 $2270mJ/cm^2$에서 $26mJ/m^2$ 이하의 표면에너지를 보였으며 95% 이상의 광투과도를 보였으며 이러한 물성은 보호용 필름이 요구하는 물성에 적절하다.

인쇄회로기판 감광층 보호필름의 레이저 유도 박리 (Laser-Driven Peeling of the Photoresist-Protective Film of a Printed Circuit Board)

  • 민형석;허준연;이지영;이명규
    • 한국광학회지
    • /
    • 제26권5호
    • /
    • pp.261-264
    • /
    • 2015
  • 본 논문에서는 인쇄회로기판의 감광층 보호필름을 532 nm 파장의 나노초 레이저의 단일펄스로 박리할 수 있음을 보여준다. 인쇄회로기판의 가장자리를 9 mm 크기의 레이저 빔으로 국부적으로 박리시킨 후 스카치테이프를 레이저 조사에 의해 초기 박리 된 영역에 붙여 전체 보호필름을 떼어내었는데, 160 - 170 mJ의 펄스에너지 범위에서는 10회의 반복된 실험 모두에서 감광층 손상 없는 박리에 성공하였다. 보호필름 초기 박리에 레이저를 사용하는 방식은 기계적 압착에 바탕을 둔 기존의 널링방식과는 달리 감광층에 손상을 유발하지 않는 비접촉 방식으로써, 인쇄회로기판 제조공정에 보다 효율적으로 사용될 수 있을 것으로 판단된다.

SiC 복합체 보호막 금속 피복관의 개발 및 고온산화 특성 분석 (Development of a Metal Cladding with Protective SiC Composites and the Characteristics on High temperature Oxidation)

  • 노선호;이동희;박광헌
    • 한국표면공학회지
    • /
    • 제48권5호
    • /
    • pp.218-226
    • /
    • 2015
  • The goal of this study is to investigate a metal cladding that contains SiC composites as a protective layer and analysis the characteristics of the specimens on high temperature oxidation To make SiC composites, the current process needs a high temperature (about $1100^{\circ}C$) for the infiltration of fixing materials such as SiC. To improve this situation, we need a low temperature process. In this study, we developed a low temperature process for making SiC composites on the metal layer, and we have made two kinds: cladding with protective SiC composites made by polycarbosilane(PCS), and a PCS filling method using supercritical carbon dioxide. A corrosion test at $1200^{\circ}C$ in a mixed steam and Ar atmosphere was performed on these specimens. The result show that the cladding with protective SiC composites have excellent oxidation suprression rates. This study can be said to have developed new metal cladding with enhanced durability by using SiC composite as protective films of metal cladding instead of simple coating film.