• Title/Summary/Keyword: Cobalt Oxide

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Middle-Temperature Desulfurization Using Cobalt Oxide (코발트를 이용한 중온 영역에서의 탈황반응에 관한)

  • Bin, Jeong-Jae;Sik, Jeong-Jong
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.443-444
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    • 2003
  • The developments on desulfurization have been focused on the application to the advanced power generation systems such as integrated gasification-combined cycle (lGCC) and the gasification-molten carbonate fuel ceil (MCFC). The gas produced from the coal gasification contains H$_2$S and other hazardous sulfur compounds, which must be removed to avoid corrosion and environmental problems. (omitted)

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Electrical Properties of Cobalt Polycide Gate (코발트 폴리사이드 게이트의 전기적 특성)

  • 정연실;정시중;김주연;배규식
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.473-476
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    • 1999
  • PMOS capacitors with Ce-policide electrode were fabricated by the SADS method to study the effects of activation condition on the C-V characteristics. For the activation temperature of $600^{\circ}C$ , the capacitor using CoSi$_2$ formed from Co/Ti bilayer as diffusion source showed excellent C-V properties and the increase in V$_{th}$ with the increasing activation time. But impurties into the oxide.e.

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Inhibition of Apoptosis by Nitric Oxide in MCF-7 Cells (유방암 세포(MCF-7)에서 nitric oxide에 의한 apoptosis 억제)

  • Kim, Kyun-Ha;Roh, Sang-Geun;Park, Hae-Ryun;Choi, Won-Chul
    • Journal of Life Science
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    • v.19 no.2
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    • pp.157-162
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    • 2009
  • Nitric oxide (NO) is a diffusible, multifunctional and transcellular messenger that has been implicated in numerous physiological and pathological conditions. It has been reported that NO induced apoptosis in tumor cells, macrophage cells and inhibited apoptosis in normal cells, endothelial cells. To examine whether NO could induce apoptosis in MCF-7 cells, cells were treated with SIN-1 (3-morpholinosydnonimine), NO donor. Cell viability did not change in SIN-1 treated cells for 48 h and there was no significantly changes in cell cycle progression or growth pattern by FACS analysis. But p53 protein, an apoptosis-related factor, increased SIN-1 treatment time dependently. Bcl-2, MDM2 and p21 were also accumulated. Bax level did not change. A major role of inhibiting apoptosis by NO in MCF-7 cells, cobalt chloride ($CoCl_2$) was added to cells preincubated with SIN-1. Whereas $CoCl_2$ treated cells underwent apoptosis, for 24 h SIN-1 preincubated cells were not induced apoptosis. Inactivated proteins, MDM2 and bcl-2, by $CoCl_2$ levels also increased in SIN-1 pre-treated cells. These results suggested that SIN-1 blocked p53 by MDM2 activation and inhibited apoptosis by inducing p21 and bcl-2 expression.

Synthesis of Ultrafine TiC-15%Co Powder by Thermochemical Method (열화학적 방법에 의한 초미립 TiC-15%Co 분말의 합성)

  • 홍성현;탁영우;김병기
    • Journal of Powder Materials
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    • v.10 no.4
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    • pp.281-287
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    • 2003
  • Ultrafine TiC-15%Co powders were synthesized by a thermochemical process, including spray drying, calcination, and carbothermal reaction. Ti-Co oxide powders were prepared by spray drying of aqueous solution of titanium chloride and $Ti(OH)_2$ slurry, both containing cobalt nitrate, fellowed by calcination. The oxide powders were mixed with carbon powder to reduce and carburize at 1100~125$0^{\circ}C$ under argon or hydrogen atmosphere. Ultrafine TiC particles were formed by carbothermal reaction at 1200~125$0^{\circ}C$, which is significantly lower than the formation temperature (~1$700^{\circ}C$) of TiC particles prepared by conventional method. The oxygen content of TiC-15%Co powder synthesized under hydrogen atmosphere was lower than that synthesized under argon, suggesting that hydrogen accelerates the reduction rate of Ti-Co oxides. The size of TiC-15%Co powder was evaluated by FE-SEM and TEM and Identified to be smaller than 300 nm.

Synthesis of Ultrafine TaC-5%Co Composite Powders using Tantalum Oxalate Solution (수산 탄탈륨 용액을 이용한 초미립 TaC-5%Co 복합 분말의 합성)

  • 권대환;홍성현;김병기
    • Journal of Powder Materials
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    • v.10 no.4
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    • pp.255-261
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    • 2003
  • Ultrafine TaC-5%Co composite powders were synthesized by spray conversion process using tantalum oxalate solution and cobalt nitrate hexahydrate(Co($(NO_3)_2$ . 6$H_2O$). The phase of Ta-Co oxide powders had amorphous structures after calcination below 50$0^{\circ}C$ and changed $Ta_2O_5$, $TaO_2$ and $CoTa_2O_6$ phase by heating above $600^{\circ}C$. The calcined Ta-Co oxide powders were spherical agglomerates consisted of ultrafine primary particles <50 nm in size. By carbothermal reaction, the TaC phase began to form from 90$0^{\circ}C$. The complete formation of TaC could be achieved at 105$0^{\circ}C$ for 6 hours. The observed size of TaC-Co composite powders by TEM was smaller than 200 nm.

Electrochemical Characteristics of supercapacitor using organic-inorganic electrode (유-무기 복합전극을 이용한 수퍼커패시터의 전기화학적 특성)

  • Kim, Hong-Il;Kim, Sang-Gil;Yuk, Gyung-Chang;Park, Soo-Gil
    • Proceedings of the KIEE Conference
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    • 2002.11a
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    • pp.164-166
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    • 2002
  • Over the past two decades, the electrochemical supercapaictors are receiving growing attention due to their possible applications as power backup in electronic equipment and electrical vehicles. Both of amorphous cobalt oxide and manganese dioxide were prepared by sol-gel process reported in our previous work. Nano-structured supramolecular oligomer of 1,5-diamino anthraquinone(DAAQ) coated metal oxides were successfully prepared by electrochemical oxidation from an acidic non-aqueous medium. We established process parameters of the technique for the formation of nano-structured materials. Furthermore, improved the capacitive properties of the nano structured metal oxide electrodes using controlled solution chemistry. $CoO_2$ and $MnO_2$-based composite electrode showed relatively good electrochemical behaviors in acidic electrolyte system with respect to specific capacity and scan rate dependency

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P123-Templated Co3O4/Al2O3 Mesoporous Mixed Oxides for Epoxidation of Styrene

  • Jung, Mie-Won;Kim, Young-Sil
    • Korean Journal of Materials Research
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    • v.22 no.6
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    • pp.316-320
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    • 2012
  • $Co_3O_4$, $Al_2O_3$ and $Co_3O_4$/$Al_2O_3$ mesoporous powders were prepared by a sol-gel method with starting matierals of aluminum isopropoxide and cobalt (II) nitrate. A P123 template is employed as an active organic additive for improving the specific surface area of the mixed oxide by forming surfactant micelles. A transition metal cobalt oxide supported on alumina with and without P123 was tested to find the most active and selective conditions as a heterogeneous catalyst in the reaction of styrene epoxidation. A bBlock copolymer-P123 template was added to the staring materials to control physical and chemical properties. The properties of $Co_3O_4$/$Al_2O_3$ powder with and without P123 were characterized using an X-ray diffractometer (XRD), a Field-Emission Scanning Electron Microscope (FE-SEM), a Bruner-Emmertt-Teller (BET) surface analyzer, and $^{27}Al$ MAS NMR spectroscopy. Powders with and without P123 were compared in catalytic tests. The catalytic activity and selectivity were monitored by GC/MS, $^1H$, and $^{13}C$-NMR spectroscopy. The performance for the reaction of epoxidation of styrene was observed to be in the following order: [$Co_3O_4$/$Al_2O_3$ with P123-1173 K > $Co_3O_4$/$Al_2O_3$ with P123-973 K > $Co_3O_4$-973 K>$Co_3O_4$/$Al_2O_3$-973 K > $Co_3O_4$/$Al_2O_3$ with P123-1473 K > $Al_2O_3$-973 K]. The existence of ${\gamma}$-alumina and the nature of the surface morphology are related to catalytic activity.

0.6 mAh All-Solid-State Thin Fim Battery Fabricated on Alumina Substrate (알루미나 기판상에 구현된 0.6mAh급 전고상 박막전지)

  • Park, H.Y.;Nam, S.C.;Lim, Y.C.;Choi, K.G.;Lee, K.C.;Park, G.B.;Cho, S.B.
    • Journal of the Korean Electrochemical Society
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    • v.8 no.4
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    • pp.181-185
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    • 2005
  • Lithium cobalt oxide thin film cathode, having thickness of $2.9{\mu}m$ with area of $4cm^2$, was deposited on platinum patterned alumina substrate by radio frequency magnetron sputtering. Li/Co molar ratio, which is an important factor for battery performance, was measured as a function of argon working pressure and applied R.F. power. Constant current charge and discharge performances were characterized with high rate discharge and cycling behavior. Using AC impedance analysis, internal resistance of the thin film battery was measured and simulated by proposed equivalent circuit model.