• Journal of Korean Society for Atmospheric Environment
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• v.8 no.1
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• pp.84-91
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• 1992

Hydrodesulfurization of thiophene was studied over $Ni-W/TiO_2-ZrO_2$ catalysts in a fixed bed flow reactor. The ranges of experimental conditions were at the temperatures between 200$^\circ$C and 360$^\circ$C, the pressures between 20 X $10^5$ Pa. The catalysts were reduced with the flow of 10 L/hr of $H_2$ at the temperature of 350$^\circ$C. It was found that $TiO_2-ZrO_2$ supported catalysts had similar activity to $\gamma-Al_2O_3$ supported. The largest surface areas and the highest acidity occured as the binary oxides were mixed with equal molar ratios. The HDS increased with increasing temperatures, pressures and contact times.

• Journal of the Korean Ceramic Society
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• v.33 no.12
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• pp.1380-1386
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• 1996

The effects of urea addition and reaction conditions were examined in the prepareation of zirconia coated SiC whiskers through surface precipitation taking place during high-temperature aging of Zr(SO4)2 solutions containing the whiskers. More dense zirconia-hydrate was precipitated on the surfaces of the whiskers in the presence of urea. The ratio of the concentration of Zr(SO4)2 to the amount of added whiskers was the most important factor to confine the precipitation of zirconia-hydrate only at the surfaces of the whiskers The from of the coating layers was unchanged after heat-treatment leading to the dehydration and crystallization of the layers.

• The Korean Journal of Ceramics
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• v.3 no.4
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• pp.253-256
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• 1997

Epitaxially grown Pb(Zr, Ti)O$_3$thin films were prepared on LaAlO$_3$substrates by the dipping pyrolysis process using metal naphthenates as starting materials Homogeneous Pb-Zr-Ti solutions with toluene were spin-coated onto the substrates and pyrolyzed at 50$0^{\circ}C$ Highly oriented Pb(Zr, Ti)O$_3$films confirmed by X-ray diffraction $\theta$-2$\theta$ scans were obtained by heat-treated at 75$0^{\circ}C$ in air The X-ray pole-figure analysis and reciprocal-space mapping of the resulting 0.6$\mu\textrm{m}$ films showed that the thin films comprising the c-axis oriented tetragonal phase have an epitaxial relationship with the LaAlO$_3$substrates.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.117-117
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• 2014

Thin $ZrO_2/Al_2O_3$ films were deposited on a tool steel substrate using Zr and Al cathodes in a cathodic arc plasma deposition system (CAPD), and then oxidized at $600-900^{\circ}C$ in air for up to 50 h. They effectively suppressed the oxidation of the substrate up to $800^{\circ}C$ by acting as a barrier layer against the outward diffusion of the substrate elements and inward diffusion of oxygen. However, rapid oxidation occurred at $900^{\circ}C$ due mainly to the increased diffusion and subsequent oxidation of steel as well as the crystallization of amorphous $Al_2O__3$.

• Journal of the Korean Ceramic Society
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• v.29 no.2
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• pp.119-126
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• 1992

3 mol% Y2O3-doped ZrO2 powders were prepared by hydrolysis with 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 mol/ιH2O/ethanol into 0.1 mol/ι zirconium and yttrium alkoside/ethanol. Spherical monodispersed yttria-partially stabilized zirconia particles with an average diameter of about 0.5 ${\mu}{\textrm}{m}$ were prepared by hydrolysis with 0.2 mol/ιH2O/ethanol. The as-prepared powder was amorphous and with heating it transformed into cubic up to 80$0^{\circ}C$ and into tetragonal over 100$0^{\circ}C$. 3 mol% Y2O3-doped ZrO2 powders calcined over and up to 80$0^{\circ}C$ were a mixture of tetragonal and monoclinic and only tetragonal as determined by X-ray diffraction, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.72-72
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• 2007

Ni 단일박막과 Ni-Zr 합금박막을 단결정 Si 기판위에 증착한 후 RTP를 이용하여 Ni 실리사이드 형성반응을 관찰하였고, $500^{\circ}C$에서 형성된 Ni 실리사이드 박막에 $600^{\circ}C,\;650^{\circ}C$에서 후속 열처리 공정을 수행하여 열 안정성을 평가하였다. RTP를 이용하여 실리사이드를 형성할 경우, Ni/Si 계의 경우, 고온 열처리에서 $NiSi_2$ 결정립의 과대 성장 및 단락이 발생하였지만, Ni-Zr/Si 계의 경우 첨가된 내열금속 원소가 NiSi에서 $NiSi_2$ 로의 상전이와 핵생성을 지연시켜 Ni 실리사이드 박막의 열 안정성 개선 효과를 확인하였다.

• Journal of the Korean Vacuum Society
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• v.8 no.3A
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• pp.245-248
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• 1999

Recently low resistance of gate line or data line is required for large screen size TFT-LCD panels. As a result, lower resistance Al-alloy is currently reviewed extensively and the resistivity is required smaller than 10$\mu\Omega$cm. In this paper, Al-Nd and Al-Zr thin film were deposited on glass substrated by D.C. magnetron sputtering system under various condition. Its properties were characterized by SEM, AFM, XRD and 4-point-probe. The optimal condition was $120^{\circ}C$, 125W, 0.4Pa, 30sccm (Ar) and $350^{\circ}C$, 20min. annealing. At that condition the resistivity of Al-Zr(0.9%wt.) is about 4$\mu\Omega$cm.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.144-150
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• 2003

When WC and group IV elements are added to Ti(C,N)-Ni substrate, microstructures of the cermet is changed. The microstructure gives direct effect on the property of the material. In this study, the amount of WC and group W elements of Ti(C,N) cermet tool was investigated. The composition of WC was changed from 5 to 20wt% to determine the effect of WC on the cutting performance of cermet tool. The more WC was added, the longer the tool life of the cermet tool was. The cermet with 20wt% WC showed the best fracture toughness. The effect of group W elements; ZrC, ZrN and HfC was also investigated by adding each of them to manufacture the cermet tool with fixed l4wt% WC composition. The cermet with 1wt% ZrC and 14wt% WC showed the best cutting performance among the investigated cermet tools.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.119-119
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• 2003

탄화규소나 열분해 탄소는 고온 특성 및 화학적인 안정성 이 우수하여 단미 혹은 코팅재로로 소재의 성능을 향상시키기 위하여 에너지 관련 분야, 반도체 치구 분야, 방위산업 및 항공우주 분야와 원자력 분야에서 다양하게 사용된다. 특히 원자력 분야에서는 고온형 원자로의 노심 요소 부품으로 적용 및 개발을 고려하고 있으며, 대표적인 예로 수소생산용 초고온 가스냉각로의 코팅 핵연료 입자를 들 수 있다. 일반적으로 TRISO라 불리는 가스냉각로 핵연료는 구형 $UO_2$ kemel의 주변을 PyC-SiC -PyC의 삼중 코팅층으로 둘러싸는 구조를 하고 있으며, 이 코팅층들은 kernel물질이 분열하는 동안 발생되는 내부 기체 압력을 견디는 압력용기 역할과 기체나 금속 핵분열 생성물들을 가두는 확산 장벽 역할을 하게 된다. 본 연구에서는 구형의 $UO_2$대신 선행연구를 위하여 구형 ZrO$_2$를 이용하여 증착온도나 시간 및 입력기체비 등의 화학증착 변수로 조절하여 SiC 및 PyC을 코팅하고, 각 변수들에 의한 증착층의 거동을 고찰하고자 하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.6
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• pp.267-271
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• 2003

In this work, chemical solution derived Ca-doped zirconia fiber has been prepared by using calcium- and zirconium-naphthenate. Fibrous $ZrO_2$-CaO was drawn from a sticky mixture. Dried gel fibers were finally annealed at $1000^{\circ}C$ for 1 h in argon. 91 mol%$ZrO_2$-9 mol%CaO fiber consisted of tetragonal, monoclinic and $CaZrO_3$ phases after annealing at $1000^{\circ}C$. On the other hand, samples annealed at $500^{\circ}C$ consisted of almost tetragonal single phase. Homogeneous fibers surface at $500^{\circ}C$ became rougher after $1000^{\circ}C$-annealing. The sample annealed at $1000^{\circ}C$ with relatively rough surface structure showed a high Calcium phocphate forming ability.