• Title/Summary/Keyword: GD

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Electrochemical Performance of LSCF Cathode with GDC lnterlayer on ScSZ Electrolyte

  • Hwang, Hae-Jin;Moon, Ji-Woong;Lim, Yongho;Lee, Seunghun;Lee, Eun-A
    • Journal of the Korean Ceramic Society
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    • v.42 no.12 s.283
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    • pp.787-792
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    • 2005
  • A symmetrical LSCF $(La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-\delta})\;ScSZ(89ZrO_2-10Sc_2O_3-1CeO_2)/LSCF$ electrochemical cell with a GDC (Gadolinium-Doped Ceria, $90CeO_2-10Gd_2O_3$) interlayer that was inserted between the LSCF cathode and ScSZ electrolyte was fabricated, and the electrochemical performance of these cells was evaluated. The GDC interlayer was deposited on a ScSZ electrolyte using a screen-printing technique. The GDC interlayer prevented the unfavorable solid-state reactions at the LSCF/ScSZ interfaces. The LSCF cathode on the GDC interlayer had excellent electrocatalytic performance even at $650^{\circ}C$. The Area Specific Resistance (ASR) was strongly dependent on the thickness and heat-treatment temperature of the GDC interlayer. The impedance spectra showed that the cell with a $15\~27{\mu}m$ thick GDC interlayer heat-treated at $1200^{\circ}C$ had the lowest ASR.

Fabrication and Properties of Porous Ni Thin Films

  • Choi, Sun-Hee;Kim, Woo-Sik;Kim, Sung-Moon;Lee, Jong-Ho;Son, Ji-Won;Kim, Joo-Sun
    • Journal of the Korean Ceramic Society
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    • v.43 no.5 s.288
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    • pp.265-269
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    • 2006
  • We have deposited NiO films by RF sputtering on $Al_2O_3/SiO_2/Si$ and 100 nm-thick Gd doped $CeO_2$ covered $Al_2O_3/SiO_2/Si$ substrates at various $Ar/O_2$ ratios. The deposited films were reduced to form porous Ni thin fllms in 4% $H_2\;at\;400^{\circ}C$. For the films deposited in pure Ar, the reduction was retarded due to the thickness and the orientation of the NiO films. On the other hand, the films deposited in oxygen mixed ambient were reduced and formed porous Ni films after 20 min of reduction. We also investigated the possibility of using the films for the single chamber operation by studying the electrical property of the films in the fuel/air mixed environment. It is shown that the resistance of the Ni film increases quickly in the mixed gas environment and thus further improvements of Ni-base anodes are required for using them in the single chamber operation.

A Magneto-Optic Waveguide Isolator Using Multimode Interference Effect

  • Yang, J.S.;Roh, J.W.;Lee, W.Y.;Ok, S.H.;Woo, D.H.;Byun, Y.T.;Jhon, Y.M.;Mizumoto T.;Lee,S.
    • Journal of Magnetics
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    • v.10 no.2
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    • pp.41-43
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    • 2005
  • We have investigated an optical waveguide isolator with a multimode interference section by wafer direct bonding, operating at a wavelength $1.55\;{\mu}m$. In order to fabricate the device for monolithic integration, the wafer direct bonding between a magnetic garnet material as a cladding layer and a semiconductor guiding layer has been achieved. We found that wafer direct bonding between InP and GGG $(Gd_3Ga_5O_{12})$ is effective for the integration of a waveguide optical isolator. The isolation ratio was obtained to be 2.9 dB in the device.

Gadolinium Complex of 1,4,7,10-Tetraazacyclododecane-N,N',N'',N'''-1,4,7-trisacetic Acid (DO3A) Conjugate of Tranexamates: A Quest for a Liver-specific Magnetic Resonance Imaging Contrast Agent

  • Nam, Ki-Soo;Jeong, Hyun-Jeong;Kim, Hee-Kyung;Choi, Garam;Suh, Kyung-Jin;Chang, Yongmin;Kim, Tae-Jeong
    • Bulletin of the Korean Chemical Society
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    • v.35 no.1
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    • pp.87-92
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    • 2014
  • The work is directed toward the synthesis of a series of DO3A conjugates of tranexamates (1c-e) and their Gd complexes (2c-e) for use as a liver-specific MRI CA. All these complexes show thermodynamic and kinetic stabilities comparable to those of structurally related clinical agents such as Dotarem$^{(R)}$. Their $R_1$ relaxivities also compare well with those of commercial agent, ranging 3.68-4.84 $mM^{-1}s^{-1}$. In vivo MR images of mice with 2a-e reveal that only 2a exhibits liver-specificity. Although 2b and 2c show strong enhancement in liver, yet no bile-excretion is observed to be termed as a liver-specific agent. The rest behaves much like ordinary ECF CAs like Dotarem$^{(R)}$. The new series possess no toxicity to be employed in vivo.

특집 - 산업디자인 발전 및 경쟁력을 위한 우수디자인

  • (사)한국포장협회
    • The monthly packaging world
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    • s.215
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    • pp.55-69
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    • 2011
  • 우수디자인(GOOD DESIGN)은 산업디자인진흥법에 의거, 상품의 외관, 기능, 재료, 경제성 등을 종합적으로 심사해 디자인의 우수성이 인정된 상품에 GOOD DESIGN 마크를 부여하는 제도로 지난 1985년부터 시행하고 있다. 지식경제부가 주최하고 한국디자인진흥원이 주관하는 굿 디자인은 우수한 디자인상품을 선정 장려함으로써 상품의 디자인개발을 촉진하고 독창적이고 우수한 상품디자인을 개발하여 상품의 경쟁력 강화를 통한 수출증대와 국민경제 발전에 기여해 나가고 있다. 우수디자인(GOOD DESIGN)은 제품디자인, 포장디자인, 환경디자인, 커뮤니케이션디자인, 소재표면처리디자인, 건축디자인 패션디자인, 패션디자인 등의 부문으로 나뉘어 선정, 시상하고 있다. 포장디자인의 경우 우리 생활에 사용 및 유통되는 모든 포장상품으로 환경보호 측면과 폐기물 처리과정, 재활용성 등을 고려한 포장의 기능과 디자인이 우수한 상품을 중심으로 선정하고 있으며, 제과류, 화장품류, 의약품류, 주류, 음료, 농 축 수산물, 가전제품류, 생활용품류, 잡화 등 기타 유통 중인 상품을 대상으로 시상하고 있다. 매년 대통령상 1점을 포함해 국무총리상 2점, 대상(지식경제부장관상) 6점, 최우수상(조당청장상) 15점, 우수상(한국디자인진흥원장상) 25점이 선정되며, 특별상으로 국민참여 선정 굿디자인 상품에 대한 시상식도 있다. 또한 대통령상, 국무총리상, 지식경제부장관상을 수상한 상품의 주 디자이너 및 디자인팀을 대상으로 우수디자이너상도 시상하고 있다. 본 고에서는 지난 해 2010 우수디자인(GD)상품 455점 가운데 포장디자인 부분 수상작들을 살펴보도록 한다.

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Spectral, Electrochemical, Fluorescence, Kinetic and Anti-microbial Studies of Acyclic Schiff-base Gadolinium(III) Complexes

  • Vijayaraj, A.;Prabu, R.;Suresh, R.;Kumari, R. Sangeetha;Kaviyarasan, V.;Narayanan, V.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3581-3588
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    • 2012
  • A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around -2.15 to -1.60 V The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity.

2G HTS wire with enhanced engineering current density attained through the deposition of HTS layer with increased thickness

  • Markelov, A.;Valikov, A.;Chepikov, V.;Petrzhik, A.;Massalimov, B.;Degtyarenko, P.;Uzkih, R.;Soldatenko, A.;Molodyk, A.;Sim, Kideok;Hwang, Soon
    • Progress in Superconductivity and Cryogenics
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    • v.21 no.4
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    • pp.29-33
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    • 2019
  • 2G HTS wire with high engineering current density is desired for applications where compact, high power density superconducting equipment is important. We have succeeded in enhancing engineering current density of commercial SuperOx 2G HTS wire based on GdBCO by increasing the HTS layer thickness without fast degradation of the HTS film microstructure. This was possible after improving the temperature uniformity along the HTS film deposition zone. In particular, the wire engineering current density was increased from 700-770 A/㎟ (for a 65 ㎛-thick wire without stabilisation) or 430-480 A/㎟ (for a 105 ㎛-thick stabilised wire) at the beginning of this study to almost 1200 A/㎟ (for a 67 ㎛-thick wire without stabilisation) or 770 A/㎟ (for a 107 ㎛-thick stabilised wire) at completion of this study.

Hall voltage measurement with respect to internal layout of REBCO coated conductors in an external magnetic field

  • Kim, Young Gon;Baek, Geonwoo;Han, Seunghak;Choi, Yojong;Kim, Junseong;Jeon, Haeryong;Ko, Tae Kuk
    • Progress in Superconductivity and Cryogenics
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    • v.21 no.4
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    • pp.48-52
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    • 2019
  • Recently, many studies have been reported on the magnetoresistance and Hall effect of REBCO thin films and bulk. The voltage interferes quench detection of high-temperature superconducting magnet and generates leakage current in no insulation high-temperature superconducting coil. Therefore, in this paper, experiments on magnetoresistance and Hall effect of commercial YBCO and GdBCO tapes have been carried out. As a result, anomalous voltages expected for the magnetoresistance and Hall effect of REBCO tapes were observed and analyzed. In addition, the voltage characteristics of REBCO have been identified, and the Hall coefficient are calculated for use in high magnetic field magnet applications.

Experimental investigation on the room temperature active magnetic regenerator with permanent magnet array (영구자석 배열을 이용한 능동형 자기재생 냉동기에 대한 실험적 연구)

  • Kim, Young-Kwon;Jeong, Sang-Kwon
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.186-191
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    • 2008
  • In this study, a room temperature AMRR (Active magnetic regenerative refrigerator) was fabricated, and experimentally investigated. Gadolinium (Gd) was selected as a magnetic refrigerant with Curie temperature of 293 K. Permanent magnet was utilized to magnetize and demagnetize the AMR. To produce large magnetic field above 1 T in the magnetic refrigeration space, a special arrangement of permanent magnets, so called Halbach array, is employed. Sixteen segments of the permanent magnets magnetized different direction, constitute a hollow cylindrical shaped permanent magnet. The AMR is reciprocated along the bore of the magnet array and produces cooling power. Helium is selected as the working fluid and a helium compressor is utilized to supply helium flow to the regenerator. The fabricated AMRR has different structure and compared to a convectional AMRR since it has an additional volume after the regenerator. Therefore, the cooling ability is generated not only by magnetocaloric effect of magnetic refrigerant but also by the pulse tube effect. It is verified that the cooling ability of AMR is increased due to the magnetocalric effect by the fact that the temperature span becomes $16^{\circ}C$ while the temperature span is only $8^{\circ}C$ when the magnetic field is not applied to the regenerator.

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Genetic Variation of Rice Populations Estimated Using nrDNA ITS Region Sequence

  • Wang, Dong;Hong, Soon-Kwan
    • Korean Journal of Plant Resources
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    • v.27 no.3
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    • pp.249-255
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    • 2014
  • The rice belonging to Oryza sativa is not only has significant economic importance, for it is the major source of nutrition for about 3 billion all around the world. But also plays a vital role as a model organism, because it has a number of advantages to be a model plant, such as efficient transformation system and small genome size. Many methods and techniques have been conducted to attempt to distinguish different Oryza sativa species, such as amplified fragment length polymorphism (AFLP), random amplified polymorphic DNA (RAPD), simple sequence repeat (SSR) and so on. However, studies using sequence analysis of internal transcribed spacer (ITS), a region of ribosomal RNA has not been reported until now. This study was undertaken with an aim to understand the phylogenetic relationships among sixteen isolates of Oryza sativa collected from abroad and fifteen isolates collected from Korea, using ribosomal RNA (rRNA) internal transcribed spacer (ITS) sequences to compare the phylogeny relationships among different Oryza sativa species. The size variation obtained among sequenced nuclear ribosomal DNA (nrDNA) ITS region ranged from 515bp to 1000bp. The highest interspecific genetic distance (GD) was found between Sfejare 45 (FR12) and Anapuruna (FR15). Taebong isolate showed the least dissimilarity of the ITS region sequence with other thirty isolates. This consequence will help us further understanding molecular diversification in intra-species population and their phylogenetic analysis.