• 한국식품과학회지
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• 제52권3호
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• pp.284-289
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• 2020

양조용 포도인 'Doonuri', 'Narsha', 'Cabernet Sauvignon', 'Merlot' 품종에 개량일자형(MT), 주지갱신형(MTC), 이중커튼형(GDC) 수형을 적용하여 재배할 때 수체생장, 과실 품질, 와인특성의 변화를 2년(2018, 2019년)간 비교하였다. 이중커튼형(GDC) 수형으로 재배된 양조용 품종들은 수체생장(주간부 굵기, 신초 굵기, 절간장)의 대부분 조사항목이 개량일자형(MT), 주지갱신형(MTC)에 비해 유의하게 적게 이루어졌다. 이중커튼형(GDC) 수형은 수확량이 다른 수형에 비해 1.5 내지 2배로 증가하였지만, 과실 품질(당함량, 산함량, 과립크기)에는 차이가 없는 결과를 나타내었다. 와인의 anthocyanin 함량과 적색도는 모든 적색 양조용 포도 품종에서 이중커튼(GDC) 수형 처리구에서 높은 경향이었다.

• 한국분말재료학회지
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• 제15권4호
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• pp.302-307
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• 2008

$Gd_2O_3$-doped $CeO_2$(GDC) solid solutions have been considered as a promising materials for electrolytes in intermediate-temperature solid oxide fuel cells. In this study, the nano-sized GDC powder with average panicle size of 69nm was prepared by a high energy ball milling process and its sintering behavior was investigated. Heat-treatment at $1200^{\circ}C$ of nano-sized GDC powder mixture led to GDC solid-solution. The enhanced densification over 96% of relative density was obtained after sintering at $1300^{\circ}C$ for 2h. It was found that the sinterability of GDC powder could be significantly improved by the introduction of a high energy ball milling process.

• 한국세라믹학회지
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• 제52권6호
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• pp.521-526
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• 2015

$Ce_{0.8}Gd_{0.2}O_{1.9}$(GDC20) powder was prepared from a mixture of submicron-sized $CeO_2$ powder and Gd precipitates using ammonium carbonate $((NH_4)_2CO_3)$ as a precipitant. The mixture was calcined at $700^{\circ}C$ for 4 h followed by ball-milling that resulted in the GDC powder with an average particle size of $0.46{\mu}m$. The powder had a very uniform particle size distribution with particle sizes ranging from $0.3{\mu}m$ to $1{\mu}m$. Sintering of undoped GDC samples did not show a relative density of 99.2% until the temperature was increased to $1500^{\circ}C$, whereas GDC samples doped with 5 mol% CoO exhibited a significant densification at lower temperature reaching a relative density of 97.6% at $1100^{\circ}C$ and of 98.8% at $1200^{\circ}C$.

• 한국세라믹학회지
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• 제51권3호
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• pp.224-230
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• 2014

Nano-sized gadolinium-doped ceria (GDC)/nickel particle-dispersed $La_ySr_{1-y}Ti_{1-x}Fe_xO_3$ (LSFTO)-based composite solid oxide fuel cell anodes were fabricated by an infiltration method and the effects of the GDC/Ni nanoparticles on the anode polarization resistance and cell performance were investigated in terms of the infiltration time and nickel content. The anodic polarization resistance of the LSFTO anode was significantly enhanced by GDC and/or Ni infiltration and it decreased with increasing infiltration time and Ni content, respectively. It is believed that the observed phenomena are associated with enhancement of the ionic conductivity and catalytic activity in the nanocomposite anodes by the addition of GDC and Ni. Power densities of cells with the LSFTO and LSFTO-GDC/Ni nanocomposite anodes were 150 and $300mW/cm^2$ at $800^{\circ}C$, respectively.

• 한국세라믹학회지
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• 제42권12호
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• pp.816-820
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• 2005

The doped-ceria is a strong candidate material for an intermediate temperature SOFC. However, the mechanical strength and the magnitude of electrical conductivity need to be increased at low sintering temperature. In this study, to improve both properties, $1at\% $ of Mg, Ca, Cr, Fe, Co, Ni, Cu, Ga, and Zr were added to the GDC20 ($20at\%$ Gd-doped Ceria) and sintered at $1350^{\circ}C$ that is $250^{\circ}C$ lower than $1600^{\circ}C$. With addition, the relative density of the sintered sample increased. Fe, Co, Ni, Cu, Ga doped-GDC20 showed high relative density over $92\%$. Among them, Ga doped-GDC20 showed the most improved sinterability. The conductivity of doped­GDC20 increased by $\~10$ times at $300\~700^{\circ}C$.

• Journal of Electrochemical Science and Technology
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• 제2권1호
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• pp.32-38
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• 2011

The composite barium strontium cobalt ferrite (BSCF) cathodes were investigated in the intermediate temperature range of solid oxide fuel cells (SOFCs). The characteristics and electrochemical performances of composited BSCF/samarium doped ceria (SDC); BSCF/gadolinium doped ceria (GDC); and BSCF/SDC/GDC were compared to single BSCF cathode. The BSCF used in this study were synthesized using glycine nitrate process and mechanically mixing was used to fabricate a composite cathode. Using a composite form, the thermal expansion coefficient (TEC) could be reduced and BSCF/SDC/GDC exhibited the lowest TEC value at $18.95{\times}10^{-6}K^{-1}$. The electrochemical performance from half cells and single cells exhibited nearly the same trend. All the composite cathodes gave higher electrochemical performance than the single BSCF cathode (0.22 $Wcm^{-2}$); however, when two kinds of electrolyte were used (BSCF/SDC/GDC, 0.36$Wcm^{-2}$), the electrochemical performance was lower than when the BSCF/SDC (0.45 $Wcm^{-2}$) or BSCF/GDC (0.45 $Wcm^{-2}$) was applied as cathode ($650^{\circ}C$, 97%$H_2$/3%$H_2O$ to the anode and ambient air to the cathode).

• 디지털콘텐츠
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• 5호통권132호
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• pp.58-59
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• 2004

GDC(Game Developer Conference) 2004는 지난해와 마찬가지로 미국 서부의 조용한 시골 산호세에서 개최됐다. 세션 참가를 위해 따뜻한 아침했살과 상쾌한 공기를 마시며 GDC에서 제공하는 셔틀버스를 타고 행사장으로 향할때 바깥 풍경을 통해 느낀 점은 간혹 어도비나 썬 마이크로시스템즈 같은 글로벌 기업들의 거대한 건물이 가끔식 눈에 띄긴 했지만, 도시의 전반적인 분위기는 한적한 시골의 분위기를 풍기는 조용한 도시였다. 내년부터 샌프란시스코에서 GDC행사가 진행된다고 하니 한편으로는 이제까지 산호세로의 직항로가 없어 버스나 국내선을 갈아타야 했던 번거러움이 없어져 반갑기도 하지만, 다른 한편으로는 이런 한적하고 조용한 분위기를 느낄 수 없을 것 같아 약간 아쉽기도 하다. 올해는 지난 3월 22일 부터 3월 26일까지의 일정으로 각종 엑스포와 세션들이 산호세 컨벤션 센터를 중심으로 진행됐다. 대부분의 세션들은 컨벤션센터와 주위의 호텔 세미나 룸에서 이뤄졌고 일부 많은 개발자들이 몰릴 것으로 예상됐다. 키노츠(Key notes)부분들은 컨벤션 센터의 맞은편인 시빅오디토리움(Civic Auditorium)에서 진행됐다.

• 디지털콘텐츠
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• 4호통권143호
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• pp.96-97
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• 2005

전세계 게임 개발자들을 위한 행사인 게임개발자컨퍼런스(Game Developers Conference, 이하 GDC) 2005가 지난달 7~8일 이틀간 미국 샌프란시스코에서 개최됐다. 새로운 개최 도시인 샌프란시스코만큼이나 다양하고 활기가 넘쳤던 이번 컨퍼런스에서는 게임산업의 미래를 엿볼 수 있는 발표가 연이었다.

• 한국재료학회지
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• 제18권12호
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• pp.660-663
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• 2008

Ni-GDC (gadolinia-doped ceria) composite powders, the anode material for the application of solid oxide fuel cells, were prepared by a solution reduction method using hydrazine. The distribution of Ni particles in the composite powders was homogeneous. The Ni-GDC powders were sintered at $1400^{\circ}C$ for 2 h and then reduced at $800^{\circ}C$ for 24 h in 3% $H_2$. The percolation limit of Ni of the sintered composite was 20 vol%, which was significantly lower than these values in the literature (30-35 vol%). The marked decrease of percolation limit is attributed to the small size of the Ni particles and the high degree of dispersion. The hydrazine method suggests a facile chemical route to prepare well-dispersed Ni-GDC composite powders.

• 한국세라믹학회지
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• 제47권2호
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• pp.199-204
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• 2010

A dual-phase ceramic membrane consisting of gadolinium-doped ceria (GDC) as an oxygen ion conducting phase and $MnCo_2O_4$ as an electron conducting phase was fabricated by sintering a GDC and $MnCo_2O_4$ powder mixture. The $MnCo_2O_4$ was found to maintain its spinel structure at temperatures lower than $1200^{\circ}C$. (Mn,Co)(Mn,Co)$O_4$ spinel, manganese and cobalt oxides formed in the sample sintered at $1300^{\circ}C$ in an air atmosphere. XRD analysis revealed that no reaction phases occurred between GDC and $MnCo_2O_4$ at $1200^{\circ}C$. The electrical conductivity did not exhibit a linear relationship with the $MnCo_2O_4$ content in the composite membranes, in accordance with percolation theory. It increased when more than 15 vol% of $MnCo_2O_4$ was added. The oxygen permeation fluxes of the composite membranes increased with increasing $MnCo_2O_4$ content and this can be explained by the increase in electrical conductivity. However, the oxygen permeation flux of the composite membranes appeared to be governed not only by electrical conductivity, but also by the microstructure, such as the grain size of the GDC matrix.