• Title/Summary/Keyword: coating properties

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A Study on the Test Methods of Bond Strength in Waterproofing and Anti-corrosion Materials by Reversed Pressure (역수압 작용을 고려한 방수·방식재의 부착강도 시험방법에 관한 연구)

  • Kim, Meong-Ji;Choi, Su-Young;Choi, Sung-Min;Oh, Sung-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.232-233
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    • 2014
  • Recently, water treatment facility is usually eastablished in underground, and waterproofing and anti-corrosion materials for concrete structures applied water treatment tank is developing in various ways. However, as the limit of research focused on durability improvement of top coating material, it is insufficient to study on the adhesion strength between the concrete surface and primer. Therefore, there is to confirm the adhesion of between concrete surface and the three primers used as anti-corrosion waterproofing materials, and to investigate the properties of adhesion strength according to the condition such as wet codition and water pressure condition of the concrete surface in this study.

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Capacitance-Voltage Characteristics of MIS Capacitors Using Polymeric Insulators

  • Park, Jae-Hoon;Choi, Jong-Sun
    • Journal of Information Display
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    • v.9 no.2
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    • pp.1-4
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    • 2008
  • In this study, we investigate the capacitance-voltage (C-V) characteristics of metal-insulator-semiconductor (MIS) capacitors consisting of pentacene, as an organic semiconductor, and polymeric insulators such as poly(4-vinylphenol) (PVP) orpolystyrene (PS) prepared by spin-coating process, to analyze the interfacial characteristics between pentacene and polymeric insulators. Compared with the device with PS, the MIS capacitor with PVP exhibited a pronounced shift in the flat-band voltage according to the bias sweep direction. This hysteric feature in the C-V characteristics is thought to be attributed to the trapped charges at the interface between pentacene and PVP owing to the hydrophilicity of PVP. From the experimental results, we can conclude that surface polarity of polymeric insulator has a critical effect on the interfacial properties, thereby affecting the bias stability of organic thin-film transistors.

The Crystallographic Properties of TiC Deposited on Different Substrate Steel by Chemical VaporDeposition (화학증착법에 의한 여러 가지 강들위에 증착된 TiC의 결정학적 특성)

  • 윤순길;김호기
    • Journal of the Korean Ceramic Society
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    • v.24 no.6
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    • pp.519-526
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    • 1987
  • TiC was deposited onto several substrate steels by the Chemical Vapor Deposition technique from TiCl4-CH4-H2 gas mixtures in the horizontal resistance furnace. Deposition rates and morphologies of the coatings were investigated with the carbon contents. Deposition thickness increased linearly with the deposition time in the Presence of CH4 gas. The various interlayers of coating by EDS and X-ray Diffraction were proved as Cr7C3 and Fe3C. Chromium contents did not affect the preferred orientation of TiC deposit. The deposition was controlled by a mass transport and a surface reaction in case of 1 wt% C-5.25 wt% Cr steel irrespective of deposition temperature.

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Evaluation of Thermal Durability of Thermal Barrier Coating and Change in Mechanical Behavior

  • Lee, Dong Heon;Kang, Nam Kyu;Lee, Kee Sung;Moon, Heung Soo;Kim, Hyung Tae;Kim, Chul
    • Journal of the Korean Ceramic Society
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    • v.54 no.4
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    • pp.314-322
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    • 2017
  • This study investigates changes in the mechanical behavior, such as changes in indentation load-displacement curve, wear resistance and contact fatigue resistance of thermal barrier coatings (TBCs) by thermal cycling test and thermal shock test. Relatively dense and porous TBCs on nickel-based bondcoat/superalloy are prepared; the highest temperature applied during thermal durability test is $1350^{\circ}C$. The results indicate that the porous TBCs have relatively longer lifetime during thermal cycling and thermal shock tests, while denser TBCs have relatively higher wear and contact fatigue resistance. The mechanical behavior is influenced by sintering of the TBCs by exposure to high temperature during tests.

An Overview of Research Trends in Antibacterial Coatings on Titanium Implants (임상가를 위한 특집 3 - 티타늄 임플란트의 항균코팅 동향)

  • Kim, Woo-Hyun;Kim, Kyoung-Nam
    • The Journal of the Korean dental association
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    • v.48 no.2
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    • pp.113-118
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    • 2010
  • Titanium and titanium alloys are the most common materials used for dental and biomedical implants, owing to their biocompatibility and favourable mechanical properties. However infection of the region surrounding a dental implant by pathogenic microorganisms is a significant factor in implant failure. Prevention and control of microbial colonization of implant surfaces is considerable interest to the biomedical community. One important strategy is to render the implant surface antibacterial by impeding the formation of biofilm. A number of approaches have been proposed for this purpose. Therefore, we reviewed the researches of antibacterial coatings on titanium implants in this articles.

The Control of Electrostatic Characteristics in Toner Type Paper-like Display

  • Lee, S.G.;Kwon, S.H.;Cho, W.K.;Song, M.B.;Kim, Y.W.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1158-1161
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    • 2006
  • The toner type paper-like display (PLD) has been developed with two polymer particles having opposite polarity which is composed of polymer, colorant and external additives (nano-sized silica). Nano-sized silica with triboelectric charge was used for the charge control agent (CCA) and influenced on the electrostatic properties of the silica-coated polymer particles. The PLD cell using silica-coated particles (200 seconds) had shown a good white appearance and low driving voltage. The result could be explained in terms of the surface morphology and the cohesiveness depending on the silica coating time.

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Analysis of Enhancement in Phosphor Performance induced by Surface Treatments

  • Jeon, Duk-Young;Bukesov, Sergey A.;Kim, Jin-Young;Park, Zin-Min;Lee, Dong-Chin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.370-373
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    • 2003
  • A search for a new phosphor composition of excellent performance in systematic ways requires lots of research efforts, and often turns out to be very timeconsuming and difficult. Thus, usually practical ways are taken to improve the performance of phosphors. A few examples of practical surface treatments on phosphors such as $In_2O_3$ coating on $ZnGa_2O_4:Mn$, phosphoric acid treatment on ZnS:Ag,Cl, and base KOH treatment with ultrasonication on ZnS:Ag,Cl are presented. The reasons for the improvement of luminescence intensity or degradation properties after these treatments are discussed based upon careful analyses on the surface of the phosphors and a proposed model on charge carriers generated by electron beam excitation.

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The Fabrication of Ferroelectric PZT thin films by Sol-Gel Processing (졸-겔법에 의한 강유전성 PZT박막의 제작)

  • Lee, Byoung-Soo;Lee, Duch-Chool
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.51 no.2
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    • pp.77-81
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    • 2002
  • In this study, PZT thin films were fabricated using sol-gel processing onto Si/$SiO_2$/Ti/Pt substrates. PZT sol with different Zr/Ti ratio(20/80, 30/70, 40/60, 52/48) were prepared, respectively. The films were fabricated by using the spin-coating method on substrates. The films were heat treated at $450^{\circ}C$, $650^{\circ}C$ by rapid thermal annealing(RTA). The preferred orientation of the PZT thin films were observed by X-ray diffraction(XRD), and Scanning electron microscopy(SEM). All of the resulting PZT thin films were crystallized with perovskite phase. The fine crystallinity of the films were fabricated. Also, we found that the ferroelectric properties from the dielectric constant of the PZT thin films were over 600 degrees, P-E hysteresis constant. And the leakage current densities of films were lower than $10^{-8}A/cm^2$. It is concluded that the PZT thin films by sol-gel process to be convinced of application for ferroelectric memory device.

Photovoltaic Properties of Sintered Cd$_{1-x}$ZnxS/CdTe Heterojunction Solar Cells (소결체 Cd$_{1-x}$ZnxS/DdTe 이종접합 태양전기의 특성)

  • 설여송;임호빈
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1989.06a
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    • pp.56-58
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    • 1989
  • All-polycrystalline Cd$_1$-xZnxS/CdTe solar cells have been fabricated by coating CdTe slurries with 4.5 wt% of CdCl$_2$on the sintered Cd$_1$-xZnxS films and by sintering CdTe layer at 6$25^{\circ}C$ for lh in nitrogen atmosphere. Solar efficiency of the sintered Cd$_1$-xZnxS/CdTe solar cells increases as the Zn content increases up to x=0.06 and then decreases with further increase in the Zn content. A solar efficiency of 12.5% under a solar intensity of 76mW/$\textrm{cm}^2$ was observed in a Cd 0.94 Zn0.06S/CdTe solar cell. By optimizing the amount of CdCl$_2$in the slurry and sintering conditions, it is possible to produce Cd$_1$-xZnxS/CdTe solar cells with efficiency higher than 12%.

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Detection of odorants and study on the odorant sensor system by using SAW device (SAW 디바이스를 이용한 냄새물질 측정 및 냄새센서 시스템의 연구)

  • 장상목;김기영;김종민;최용성;권영수
    • Electrical & Electronic Materials
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    • v.8 no.1
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    • pp.48-55
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    • 1995
  • A surface acoustic wave (SAW) sensor for the detection of odorants has been constructed by depositing various phospholipids and fatty acids onto the surface of the SAW device. The characteristics of a SAW device operating at 310 MHz deposited with silicon monoxide were analyzed. Menthone, amylacetate, acetoin, and other organic gases show different affinities to the coated lipids. An explanation is given for different odorant affinities based on the monolayer properties of phospholipids. The identification of odorants depending on the tkpe of lipid used for coating is discussed in terms of the similarity of their normalized resonant frequency shift patterns. Using a number of different lipid-coated SAW devices, odorants can be identified by a computerized pattern recognition algorithm.

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