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  • Title/Summary/Keyword: metallic structure

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Effect of Machining Characteristics Aluminium Alloy added Composition Elements (알루미늄 합금의 성분원소가 절삭 특성에 미치는 영향)

  • 채왕석;김경우;최현민;김동현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.857-860
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    • 1997
  • The purpose of this research was to study the influence of machining characteristics for aluminum alloys. The effect of metallic microstructural variables on the measures of machinability of aluminum alloys has no been adequately investigated. Machining Characteristics are influenced significantly by mechanical characteristics, composition and structure of material etcs. For improvement of machining characteristics, various studies are reported. In this paper, composition elements add to aluminum alloys within the limit of sustaining mechanical characteristics of metallic material. We have analyzed dynamic characteristics of cutting resistance, tensile strength value, hardness value etcs.

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A Study on Microstructures and Mechanical Properties of A356/coated SiC Composites Fabricated by Squeeze Casting (Squeeze Casting법에 의해 제조된 A356/coated SiC복합재료의 미세조직과 기계적 특성에 관한 연구)

  • Lee, Kyung-Ku;Lee, Doh-Jae
    • Journal of Korea Foundry Society
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    • v.14 no.5
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    • pp.429-437
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    • 1994
  • Influence of interfacial structure between matrix and particle in A356/coated SiC composite fabricated by squeeze casting method was studied. Experimental variables are types of coated metallic film on SiC particles such as Cu, Ni-P, and applied pressure for squeeze casting. It was found that coating treatment on SiC particles improves the wetting of liquid A356 alloy on SiC particles. SiC particle distribution is very homogeneous in A356 matrix alloy which is fabricated by squeeze casting. Analysing the surface morphology of fractured A356/coated SiC, it was concluded that metallic thin film by coating treatment on SiC particle improves the interfacial bonding between particle and matrix, and so does on mechanical properties such as tensile strength. However, there was on significant difference in hardness between those composite made of as-received SiC particle and coated SiC particle.

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Effect of Metallic Tungsten Concentration on Resistance Switching Behavior of Sputtered W-doped NbOx Films

  • Lee, Gyu-Min;Kim, Jong-Gi;Na, Hui-Do;Son, Hyeon-Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.288-288
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    • 2012
  • In this study, we investigated that the resistance switching characteristics of W-doped NbOx films with increasing W doping concentration. The W-doped NbOx based ReRAM devices with a TiN/W-doped NbOx/Pt/Ti/SiO2 were fabricated on Si substrates. The 50 nm thick W-doped NbOx films were deposited by reactive dc magnetron co-sputtering at 400C and oxygen partial pressure of 35%. Micro-structure of W-doped NbOx films and atomic concentration were investigated by XRD, TEM and XPS, respectively. The W-doped NbOx films showed set/reset resistance switching behavior at various W doping concentrations. The process voltage of set/reset is decreased and whereas the initial current level is increased with increasing W doping concentration in NbOx films. The change of resistance switching behavior depending on doping concentration was discussed in terms of concentration of metallic tungsten of oxygen of W-doped NbOx.

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Cost-effective structural health monitoring of FRPC parts for automotive applications

  • Mitschang, P.;Molnar, P.;Ogale, A.;Ishii, M.
    • Advanced Composite Materials
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    • v.16 no.2
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    • pp.135-149
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    • 2007
  • In the automobile industry, structural health monitoring of fiber reinforced polymer composite parts is a widespread need for maintenance before breakdown of the functional elements or a complete vehicle. High performance sensors are generally used in many of the structural health monitoring operations. Within this study, a carbon fiber sewing thread has been used as a low cost laminate failure sensing element. The experimentation plan was set up according to the electrical conductance and flexibility of carbon fiber threads, advantages of preforming operations, and sewing mechanisms. The influence of the single thread damages by changing the electrical resistance and monitoring the impact location by using carbon thread sensors has been performed. Innovative utilization of relatively cost-effective carbon threads for monitoring the delamination of metallic inserts from the basic composite laminate structure is a highlighting feature of this study.

Development of Porous Metal Materials and Applications

  • Fang, Y.;Wang, H.;Zhou, Y.;Kuang, C.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.599-600
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    • 2006
  • This paper described the state of art of porous metal materials, the typical manufacturing technologies and performances of sintered metal porous materials, with emphasis on the recent research achievements of CISRI in development of porous metal materials. High performance porous metal materials, such as metallic membrane, sub-micron asymmetric composite porous metal, large dimensional and structure complicated porous metal aeration cones and tube, metallic catalytic filter elements, lotus-type porous materials, etc, have been developed. Their applications in energy industry, petrochemical industry, clean coal process and other industrial fields were introduced and discussed.

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Field Testing Center Design of Cathodic Protection System for Maritime Metallic Structures (해양구조물 전기방식시스템 현장적용실험장 설계)

  • Ha, Tae-Hyeon;Bae, Jeong-Hyo;Lee, Hyeon-Gu;Ha, Yun-Cheol;Kim, Dae-Gyeong
    • Proceedings of the KIEE Conference
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    • 2003.11c
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    • pp.633-636
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    • 2003
  • Most of maritime metallic structures are adopted a CP(Cathodic Protection) System for protection of corrosion in advanced country. So, we had been developed a remote corrosion monitoring control system. And we want to know the characteristics of efficiency, reliability, durability and so on. On the view point of it, we have to test in real field. in terms of design, cathodic protection systems, corrosion monitoring systems and optimal corrosion control systems compare to general commercial products. So, these systems have being studied to improve their capability. In this paper, the result of field testing center design of intelligent cathodic protection system including anodes, a real-time wireless remote corrosion monitoring and corrosion control system are described in naval ports.

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Effect of Change of Sleeve Type on Fireproofing Performance of Through-Penetration Firestop System on Metallic Pipes (금속관 설비관통부 내화채움 시스템의 슬리브 종류 변화가 내화시험에 미치는 영향)

  • Choi, Hong-Beom;Jeong, A-Yeong;Lee, Hyung-DO;Park, Jin-O;Ok, Chi-Yeol
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.327-328
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    • 2023
  • In this paper, the effect of change of sleeve type on fireproofing performance of through-penetration firestop system on metallic pipes was analyzed. As a result, if the material of the sleeve is high in thermal conductivity and thick, a large amount of heat is transferred to the top of the support structure.

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Thermal Annealing Effect on Delta-doped P-type Nanolayer for Silicon Interconnection of Tandem Solar Cells (텐덤 태양전지의 실리콘 배선용 델타도핑된 P형 나노층의 열처리 효과에 관한 연구)

  • Inseung Lee;Keunjoo Kim
    • Journal of the Semiconductor & Display Technology
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    • v.23 no.4
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    • pp.65-71
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    • 2024
  • We investigated the thermal activation of the boron delta-doped tunneling diode for the silicon interconnection of the tandem solar cell applications. The tandem cell with two serial pn junctions for the charge carrier collection needs the metallic interconnection between two junctions. Instead of metallic thin film deposition, the boron delta-doped layer can be sandwiched in the interface region by plasma-enhanced chemical vapor deposition. In this work, the ptype delta-doped sample was formed as a tunneling junction diode and showed the Ohmic behavior at a low voltage and Schottky characteristics at a high bias. This indicates that the boron dopant nanolayer forms the bonding structure with the Si lattice for the hole carrier formation by showing the electron spin resonance.

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A Study on Optimization of a Multi-Layered Metallic Disk Array Structure for Shaping of Flat-Topped Element Patterns (구형 빔 패턴 형성을 위한 다층 원형 도체 배열 구조의 최적화 연구)

  • 엄순영;박한규
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.10
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    • pp.985-995
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    • 2003
  • In this paper, a study on optimization of three dimensional multi-layered metallic disk array structure(MDAS) excited by circular waveguides was performed to shape efficient flat-topped element patterns(FTEP) of ±20 beam width. Each radiating element of the MDAS is composed of input, transition and radiation circular waveguides and finite metal disks stacked on radiation circular waveguide. It has an array structure of a hexagonal lattice appropriate for the conical beam scanning. The analytic algorithm for the MDAS was proposed and the code was also programmed using it. Optimal design parameters of the MDAS were determined through the optimal simulation process to obtain ±20 FTEP. Also, bandwidth characteristics for FTEP and reflection coefficients of the MDAS were investigated and, as the results, it was shown that the MDAS could shape good FTEPs of ±20 beam width in main planes at least within a 5.6 % frequency band.

Influence of Crystal Structure on the Chemical Bonding Nature and Photocatalytic Activity of Hexagonal and Cubic Perovskite Compounds

  • Lee, Sun-Hee;Kim, In-Young;Kim, Tae-Woo;Hwang, Seong-Ju
    • Bulletin of the Korean Chemical Society
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    • v.29 no.4
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    • pp.817-821
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    • 2008
  • We have investigated the influence of the crystal structure on the chemical bonding nature and photocatalytic activity of cubic and hexagonal perovskite A[Cr1/2Ta1/2]O3 (A = Sr, Ba) compounds. According to neutron diffraction and field emission-scanning electron microscopy, the crystal structure and particle size of these compounds are strongly dependent on the nature of A-site cations. Also, it was found that the face-shared octahedra in the hexagonal phase are exclusively occupied by chromium ions, suggesting the presence of metallic (Cr-Cr) bonds. X-ray absorption and diffuse UV-vis spectroscopic analyses clearly demonstrated that, in comparison with cubic Sr[Cr1/2Ta1/2]O3 phase, hexagonal Ba[Cr1/2Ta1/2]O3 phase shows a decrease of Cr oxidation state as well as remarkable changes in interband Cr d-d transitions, which can be interpreted as a result of metallic (Cr-Cr) interactions. According to the test of photocatalytic activity, the present semiconducting materials have a distinct activity against the photodegradation of 4-chlorophenol. Also the Srbased compound was found to show a higher photocatalytic activity than the Ba-based one, which is attributable to its smaller particle size and its stronger absorption in visible light region.