• Title/Summary/Keyword: Metallic

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Synthesis of Ni-based Bulk Metallic Glass Composites (Ni계 벌크 비정질 복합재의 제조)

  • Lee, Jin-Kyu
    • Journal of Powder Materials
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    • v.15 no.4
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    • pp.297-301
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    • 2008
  • The Ni-based bulk metallic glass matrix composites were fabricated by spark plasma sintering of mixture of gas-atomized metallic glass powders and ductile brass powders. The successful consolidation of metallic glass matrix composite was achieved by strong bonding between metallic glass powders due to viscous flow deformation and lower stress of ductile brass powders in the supercooled liquid state during spark plasma sintering. The composite shows some macroscopic plasticity after yielding, which was obtained by introducing a ductile second brass phase in the Ni-based metallic glass matrix.

Influences of Trap States at Metal/Semiconductor Interface on Metallic Source/Drain Schottky-Barrier MOSFET

  • Cho, Won-Ju
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.7 no.2
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    • pp.82-87
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    • 2007
  • The electrical properties of metallic junction diodes and metallic source/drain (S/D) Schottky barrier metal-oxide-semiconductor field-effect transistor (SB-MOSFET) were simulated. By using the abrupt metallic junction at the S/D region, the short-channel effects in nano-scaled MOSFET devices can be effectively suppressed. Particularly, the effects of trap states at the metal-silicide/silicon interface of S/D junction were simulated by taking into account the tail distributions and the Gaussian distributions at the silicon band edge and at the silicon midgap, respectively. As a result of device simulation, the reduction of interfacial trap states with Gaussian distribution is more important than that of interfacial trap states with tail distribution for improving the metallic junction diodes and SB-MOSFET. It is that a forming gas annealing after silicide formation significantly improved the electrical properties of metallic junction devices.

Integrability of the Metallic Structures on the Frame Bundle

  • Islam Khan, Mohammad Nazrul
    • Kyungpook Mathematical Journal
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    • v.61 no.4
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    • pp.791-803
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    • 2021
  • Earlier investigators have made detailed studies of geometric properties such as integrability, partial integrability, and invariants, such as the fundamental 2-form, of some canonical f-structures, such as f3 ± f = 0, on the frame bundle FM. Our aim is to study metallic structures on the frame bundle: polynomial structures of degree 2 satisfying F2 = pF +qI where p, q are positive integers. We introduce a tensor field Fα, α = 1, 2…, n on FM show that it is a metallic structure. Theorems on Nijenhuis tensor and integrability of metallic structure Fα on FM are also proved. Furthermore, the diagonal lifts gD and the fundamental 2-form Ωα of a metallic structure Fα on FM are established. Moreover, the integrability condition for horizontal lift FαH of a metallic structure Fα on FM is determined as an application. Finally, the golden structure that is a particular case of a metallic structure on FM is discussed as an example.

Synthesis of Ni-based Metallic Glass Composite Fabricated by Spark Plasma Sintering (방전플라즈마소결을 이용한 Ni계 비정질 복합재의 제조)

  • Kim, Song Yi;Guem, Bo Kyeong;Lee, Min Ha;Kim, Bum Sung
    • Journal of Powder Materials
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    • v.20 no.1
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    • pp.33-36
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    • 2013
  • A bulk metallic glass-forming alloy, $Ni_{59}Zr_{20}Ti_{16}Si_2Sn_3$ metallic glass powders was used for good commercial availability and good formability in supercooled liquid region. In this study, the Ni-based metallic glass was synthesized using by high pressure gas atomized metallic glass powders. In order to create a bulk metallic glass sample, the $Ni_{59}Zr_{20}Ti_{16}Si_2Sn_3$ metallic glass powders with ball-milled Ni-based amorphous powder with 40%vol brass powder and Cu powder for 20 hours. The composite specimens were prepared by Spark Plasma Sintering for the precursor. The SPS was performed at supercooled liquid region of Ni-based metallic glass. The amorphous structure of the final sample was characterized by SEM, X-ray diffraction and DSC analysis.

Characteristics of Gold and Silver Based Bi- and Tri-metallic SPR Chip in the Intensity Measurement Mode (반사광 측정 모드에서 금과 은을 사용한 이층 금속 칩과 삼층 금속 칩의 특성 연구)

  • Kim, Hyungjin;Kim, Chang-duk;Sohn, Young-Soo
    • Journal of Sensor Science and Technology
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    • v.25 no.2
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    • pp.143-147
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    • 2016
  • Characteristics of the conventional gold (Au) surface plasmon resonance (SPR) chip, bi-metallic(Au/silver (Ag)) SPR chip, and tri-metallic(Au/Ag/Au) SPR chip were investigated and compared in the intensity measurement mode for the enhancement of SPR image sensor reactivity. Reflectance curves of the Au, bi- and tri-metallic SPR chips were acquired in phosphate-buffered saline (PBS) solution and were compared. The line width of the reflectance curve of the bi-metallic chip was the narrowest among the three different types of the chips. Also, the tangential slope of the bi-metallic chip was steeper than those of the other chips. Various concentrations of bovine serum albumin (BSA) were utilized in the SPR experiment. As a result, among the above three chips reflectance variation value of the bi-metallic chip was the largest.

Physical Performance of Metallic Jacquard Fabrics (메탈릭 자카드 직물 물리적 성능평가)

  • Kang, Duck-Hee;Lee, Jung-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.1
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    • pp.149-159
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    • 2009
  • The purposes of this study are to evaluate physical performance of metallic Jacquard fabrics, and to contribute to the research and development of the women's suit made of the metallic Jacquard fabrics. First, eight fabrics were woven with two kinds of warp yarns(nylon and rayon) and weft yarn blended with various contents(0, 7, 14, 21%) of metallic yarn. Second, the mechanical properties were measured by using the KES-FB system, and physical properties such as tensile strength, tearing strength, abrasion resistance, drape, pilling, snagging, degree of crease resistance, flexural stiffness, specular gloss, folding endurance and electrostatic propensity were measured. The results were as follows. As the metal fiber content increased, bending, shear, thickness and weight increased, which imply low recovery of wrinkles. It means that metallic Jacquard fabrics enable to use as a memory fabric. 7% metallic Jacquard fabric showed a low value at total hand value, but there was little change. As the metal fiber content increased, tensile strength, tearing strength, drape coefficient, specular gloss and flexural stiffness increased, however the degree of crease resistance, electrostatic propensity and folding endurance decreased. The metallic Jacquard fabrics were excellent in snagging, abrasion resistance and pilling.

Properties of the metallic glass thin films fabricated by multicomponent single alloying target and its applications in various industrial fields

  • Shin, S.Y.;Moon, K.I.
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.05a
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    • pp.77-77
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    • 2015
  • Metallic glass alloys having dense packing structure have short range ordered structure with long range homogeneity. Therefore, they can provide complete corrosion protection and unique electrical properties. Recently, metallic glass thin films have received much attention to extend its application fields combining with PVC coating technologies. The metallic glass thin films can change the surface properties of the conventional bulk materials which need anticorrosion properties. However, multi-component alloying targets are required to fabricate the metallic glass thin films because metallic glass alloys contain more than three elements. Recently, many researchers have been reported the properties of the metallic glass thin films synthesized with multi-cathode systems or amorphous target. But, it is difficult to fabricate the large sized sputtering targets for mass production equipment with high toughness and thermal stability. In this study, newly developed sputtering target with glass forming ability and the properties of the metallic glass thin films will be introduced with respect to the various application fields such as bipolar plate in PEM fuel cell and decorative coatings for electric device and construction fields.

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A methodology for design of metallic dampers in retrofit of earthquake-damaged frame

  • Zhang, Chao;Zhou, Yun;Weng, Da G.;Lu, De H.;Wu, Cong X.
    • Structural Engineering and Mechanics
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    • v.56 no.4
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    • pp.569-588
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    • 2015
  • A comprehensive methodology is proposed for design of metallic dampers in seismic retrofit of earthquake-damaged frame structures. It is assumed that the metallic dampers remain elastic and only provide stiffness during frequent earthquake (i.e., earthquake with a 63% probability of exceedance in 50-year service period), while in precautionary earthquake (i.e., earthquake with a 10% probability of exceedance in 50-year service period), the metallic dampers yield before the main frame and dissipate most of the seismic energy to either prevent or minimize structural damages. Therefore by converting multi-story frame to an equivalent single-degree-of-freedom system, the added stiffness provided by metallic dampers is designed to control elastic story drifts within code-based demand under frequent earthquake, and the added damping with the combination of added stiffness influences is obtained to control structural stress within performance-based target under precautionary earthquake. With the equivalent added damping ratio, the expected damping forces provided by metallic dampers can be calculated to carry out the configuration and design of metallic dampers along with supporting braces. Based on a detailed example for retrofit of an earthquake-damaged reinforced concrete frame by using metallic dampers, the proposed design procedure is demonstrated to be simple and practical, which can not only meet current China's design codes but also be used in retrofit design of earthquake-damaged frame with metallic damper for reaching desirable performance objective.

Behavior of Some Metallic Ions in the Process of Ginseng Extracts Preparation (인삼(人蔘) Extract 제조과정(製造過程)중 무기금속(無機金屬)이온의 동태(動態))

  • Cho, Yung-Hyun;Lee, Joung-Sook
    • Korean Journal of Food Science and Technology
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    • v.15 no.2
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    • pp.133-134
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    • 1983
  • Some metallic ions such as copper, manganese, iron, zinc and cadmium in ginseng extract, originated from white ginseng, were determined by atomic absorption spectrophotometry. The extracts were prepared with water, 35% ethanol, 50% ethanol or 75% ethanol solution followed by filtration or centrifugation. Greater amounts of metallic ions were found in the solution filtrated by filter paper (Toyo No. 5A) or by filter cloth than in that of centrifugation. The residual amount of metallic ions in the extract decreased with increasing concentration of ethanol. The percentages of each metallic ion in ginseng extracts on the basis of original amount of metallic ions were as follows: Cu, 10.4-31.9%, Fe,5.1-19.0%, Mn,3.0-12.2% Zn,7.4-12.0%, Cd,5.9-11.8%.

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