• Title/Summary/Keyword: Novel metal

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A Novel Metal Supported SOFC Fabrication Method Developed in KAIST: a Sinter-Joining Method

  • Bae, Joongmyeon
    • Journal of the Korean Ceramic Society
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    • v.53 no.5
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    • pp.478-482
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    • 2016
  • Metal-supported SOFCs have been investigated to overcome the disadvantages of ceramic-supported SOFCs, including issues related to mechanical strength and sealing. In the case of ceramic-supported cells, the mechanical support is a brittle ceramic or cermet, and it contains expensive materials. However, metal-supported cells utilize ceramic layers that are only as thick as necessary for electrochemical functioning, thereby compensating for the disadvantages of ceramic-supported cells. The mechanical support is fabricated from inexpensive and robust metals, and the electrochemically active layers are applied directly to the metal support. The metal-supported SOFCs thus can provide a reduced system cost, ease of manufacturing, and operational advantages. Owing to these features, metal-supported SOFCs are a very promising candidate for commercialization. Given the importance of studying worldwide trends in metal-supported SOFC research for performance evaluation, this paper reviews development trends with a focus on fabrication methods. Furthermore, a novel fabrication method developed in KAIST is discussed.

The Performance of Photocatalyst filter for an Air Cleaner-Effect of novel metal (공기정화기용 광촉매 필터의 성능-귀금속 담지 영향)

  • Jang, Hyun-Tae;Kim, Jeong-Keun;Cha, Wang-Seog
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.6
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    • pp.1284-1291
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    • 2006
  • This work examined improving the activity of photocatalyts by novel metal doping for the degradation of volatile organic compounds, such as formaldehyde and acetone. The activity was determined with type of dopant novel metal and volatile organic compounds. The palladium-doped $TiO_2$ was found to be improved the decomposition of acetone. The photocatalytic degradation rate for acetone was increased with decreasing temperature to $45^{\circ}C$. The optmum temperature of photocatalytic degradation rate for formaldehyde was $75^{\circ}C$. The enhancement of reaction rate with novel metal were 1.0 wt.% of palladium for acetone, 1.0 wt.% of plaitnum for formaldehyde.

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Novel-1,3-Alternate Calix[4]thiacrown Ethers

  • Sim, Won-Bo;Lee, Jai-Young;Kwon, Jong-Chul;Kim, Moon-Jib;Kim, Jong-Seung
    • Bulletin of the Korean Chemical Society
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    • v.23 no.6
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    • pp.879-884
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    • 2002
  • A series of novel 1,3-alternate calix[4]-mono-thiacrown and -bis-thiacrowns were synhesized within good yields. The three dimensional 1,3-alternate conformation was confimed by X-ray crystal structure. From the results of two phase extraction and NMR studies on the ligand-metal complex, one can conclude that the calix[4]thiacrown ethers showed the very high selectivity for silver ion over other metal ions by an electrostatic interaction between sulfur atom and silver ion and by a $\pi-metal$ complexation.

Enhanced Electrical Performance of SiZnSnO Thin Film Transistor with Thin Metal Layer

  • Lee, Sang Yeol
    • Transactions on Electrical and Electronic Materials
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    • v.18 no.3
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    • pp.141-143
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    • 2017
  • Novel structured thin film transistors (TFTs) of amorphous silicon zinc tin oxide (a-SZTO) were designed and fabricated with a thin metal layer between the source and drain electrodes. A SZTO channel was annealed at $500^{\circ}C$. A Ti/Au electrode was used on the SZTO channel. Metals are deposited between the source and drain in this novel structured TFTs. The mobility of the was improved from $14.77cm^2/Vs$ to $35.59cm^2/Vs$ simply by adopting the novel structure without changing any other processing parameters, such as annealing condition, sputtering power or processing pressure. In addition, stability was improved under the positive bias thermal stress and negative bias thermal stress applied to the novel structured TFTs. Finally, this novel structured TFT was observed to be less affected by back-channel effect.

Conducting Metal Oxide Interdigitated Electrodes for Semiconducting Metal Oxide Gas Sensors

  • Shim, Young-Seok;Moon, Hi-Gyu;Kim, Do-Hong;Jang, Ho-Won;Yoon, Young-Soo;Yoon, Soek-Jin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.65-65
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    • 2011
  • We report the application of conducting metal oxide electrodes for semiconducting metal oxide gas sensors. Pt interdigitated electrodes have been commonly used for metal oxide gas sensor because of the low resistivity, excellent thermal and chemical stability of Pt. However, the high cost of Pt is an obstacle for the wide use of metal oxide gas sensors compared with its counterpart electrochemical gas sensors. Meanwhile, relatively low-cost conducting metal oxides are widely being used for light-emitting diodes, flat panel displays, solar cell and etc. In this work, we have fabricated $WO_3$ and $SnO_2$ thin film gas sensors using interdigitated electrodes of conducting metal oxides. Thin film gas sensors based on conducting metal oxides exhibited superior gas sensing properties than those using Pt interdigitated electrodes. The result was attributed to the low contact resistance between the conducting metal oxide and the sensing material. Consequently, we demonstrated the feasibility of conducting metal oxide interdigitated electrodes for novel gas sensors.

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Novel Ignition Method for Automotive HID lamp Ballast System (자동차 헤드라이트용 고압방전등 안정기 시스템의 새로운 점등방식)

  • Kim, Yoon-Ho;Um, Tae-Wook;Lee, Jae-Hak
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.4
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    • pp.238-243
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    • 2006
  • This paper presents novel ignition method for automotive 35W metal halide discharge lamp electronic ballast. At this study, the novel method of ignition is developed to reduce costs and size of the ballast. By use of the novel method, the voltage needed in ignition is decreased, which result in use of the lower voltage rating power devices compared with conventional method and product compactness was achieved by deleting a circuit generating negative voltage needed in ignition at an conventional circuit. In terms of luminosity, color rendering, light efficiency(lm/W) and lifespan, the metal halide lamp is superior to, but unlike halogen lamp, it have more complicated transient characteristics to reach its steady state than the conventional halogen lamp. Therefore, in this paper, the electronic ballast was designed such that the metal halide lamp could be optimized for the automotive, by applying a method of microcontroller-based digital control. The results of the proposed system is verified through various experiment results.

A SDR/DDR 4Gb DRAM with $0.11\mu\textrm{m}$ DRAM Technology

  • Kim, Ki-Nam
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.1 no.1
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    • pp.20-30
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    • 2001
  • A 1.8V $650{\;}\textrm{mm}^2$ 4Gb DRAM having $0.10{\;}\mu\textrm{m}^2$ cell size has been successfully developed using 0.11 $\mu\textrm{m}$DRAM technology. Considering manufactur-ability, we have focused on developing patterning technology using KrF lithography that makes $0.11{\;}\mu\textrm{m}$ DRAM technology possible. Furthermore, we developed novel DRAM technologies, which will have strong influence on the future DRAM integration. These are novel oxide gap-filling, W-bit line with stud contact for borderless metal contact, line-type storage node self-aligned contact (SAC), mechanically stable metal-insulator-silicon (MIS) capacitor and CVD Al process for metal inter-connections. In addition, 80 nm array transistor and sub-80 nm memory cell contact are also developed for high functional yield as well as chip performance. Many issues which large sized chip often faces are solved by novel design approaches such as skew minimizing technique, gain control pre-sensing scheme and bit line calibration scheme.

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Highly Miniaturized and Low impedance Wilkinson Power Divider on RFIC/MMIC for application to IT components of Ocean Engineering (해양 IT 소자에의 응용을 위한 RFIC/MMIC용 초소형 저임피던스 윌킨슨 전력분배기 설계)

  • Kim, Choong-Ryul;Yun, Young
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.412-416
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    • 2005
  • In this paper we propose low-impedance and miniaturized a wilkinson power divider on MMIC passive component which was fabricated by a novel microstrip line structure employing periodically perforated ground metal (PPGM). The novel microstrip line structure showed much lower impedance and shorter guided-wavelength than conventional one. Using the novel microstrip line with periodically perforated ground metal, a miniaturized 17 ${\Omega}$ power divider was fabricated. The line width of the power divider was 20 ${\mu}m$, and the size of it was 0.110 $mm^2$, which is 21 % of conventional one. The power divider exhibited good RF performances from 10 to 20 GHz.

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Electrochemical Properties of Novel Metal Powder Electrodes for Polymer Electrolyte Membrane Electrolysis

  • Kim, Chang-Hee;Kang, Kyung-Soo;Park, Chu-Sik;Hwang, Gab-Jin;Bae, Ki-Kwang
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1227-1228
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    • 2006
  • The electrochemical properties of novel metal powders were investigated for the electrode materias of polymer electrolyte memebrane electrolysis. Two types of Pt black and $IrO_2$ powder electrodes were hot-pressed on the polymer electrolyte membrane to form membrane electrode assembly. The galvanodynamic polarization methode was used to characterize the electrochemical properties of both electrodes. From the experimental results, we concluded that the $IrO_2$ powder electrode exhibits better electrochemical performance than Pt black as cathode material for the electrolysis.

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Novel solvothermal approach to hydrophilic nanoparticles of late transition elements and its evaluation by nanoparticle tracking analysis

  • Dutilleul, Marion Collart;Seisenbaeva, Gulaim A.;Kessler, Vadim G.
    • Advances in nano research
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    • v.2 no.2
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    • pp.77-88
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    • 2014
  • Solvothermal treatment of late transition metal acetylacetonates in a novel medium composed either of pure acetophenone or acetophenone mixtures with amino alcohols offers a general approach to uniform hydrophilic metal nanoparticles with high crystallinity and low degree of aggregation. Both pure metal and mixed-metal particles can be accesses by this approach. The produced materials have been characterized by SEM-EDS, TEM, FTIR in the solid state and by Nanoparticle Tracking Analysis in solutions. The chemical mechanisms of the reactions producing nanoparticles has been followed by NMR. Carrying out the process in pure acetophenone produces palladium metal, copper metal with minor impurity of $Cu_2O$, and NiO. The synthesis starting from the mixtures of Pd and Ni acetylacetonates with up to 20 mol% of Pd, renders in minor yield the palladium-based metal alloy along with nickel oxide as the major phase. Even the synthesis starting from a mixed solution of $Cu(acac)_2$ and $Ni(acac)_2$ produces oxides as major products. The situation is improved when aminoalcohols such as 2-aminoethanol or 2-dimethylamino propanol are added to the synthesis medium. The particles in this case contain metallic elements and pairs of individual metals (not metal alloys) when produced from mixed precursor solutions in this case.