• Title/Summary/Keyword: CNT-

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A New Structure of Triode-type CNT-FEAs for Enhanced Electron Emission and Beam Focusing

  • Jun, Pil-Goo;Kwak, Byung-Hwak;Noh, Hyung-Wook;Lee, Soo-Myun;Uh, Hyung-Soo;Park, Sang-Sik;Ko, Sung-Woo;Cho, Euo-Sik;Lee, Jong-Duk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.456-458
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    • 2004
  • We proposed a novel triode-type carbon nanotube field emitter arrays in which extracted gate is surrounded by CNT emitters. We carried out 3-dimensional numerical calculations of electrostatic potential for the proposed CNT-FEAs using the finite element method and compared the results with those obtained from the structure of conventional CNT-FEAs. It was found that the proposed structure could reduce the turn-on voltage for electron emission and improve beam focusing.

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A comparative study of grinding mill type on aluminium powders with carbon nano tube: traditional ball mill and planetary ball mill

  • Choe, Hui-Gyu;Choe, Gyeong-Pil;Bae, Dae-Hyeong;Lee, Seung-Baek;Lee, Ung;Kim, Seong-Su
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.11a
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    • pp.27.2-27.2
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    • 2009
  • Grinding characteristics for aluminium and carbon nanotubes (CNTs) powder during traditional and planetary ball milling investigated from the viewpoint of particle behaviour with the aimat developing CNT-dispersed samples ground based on powder metallurgy routes.In this work, a comparison between the pure aluminium and CNT input aluminium grinding was carried out to determine grinding time effect on size reduction.We observed that the use of the curly small-diameter multi-walled carbon nanotubes (MWCNTs) attributed to the beneficial role of the MWCNTs as grinding aids. It is suggested that careful choices of the sizes of CNTs and Al powders would allow fine-grinding of composite particles with uniformly distributed CNT reinforcements thereby ensuring improved properties of the final composites produced by low-temperature compacting.

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A Study on the Actuating Voltage of a Nanotweezer (나노 트위져의 구동 전압에 관한 연구)

  • Lee, Jun-Sok;Choi, Jai-Seong;Kang, Gyung-Soo;Kwak, Yoon-Keun;Kim, Soo-Hyun
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.986-990
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    • 2004
  • In this paper, we propose a method to estimate the actuating voltage of the nanotweezer made by manual assembly using carbon nanotube. The nanotweezer is composed of two CNT arms that are made by the multiwalled carbon nanotube and tungsten tip. Since the each CNT arm has the macro actuator, the nanotweezer can manipulate a large particle and it is possible to close and open the CNT arm repeatedly. The closing voltage, i.e., actuating voltage is calculated using the capacitance between the carbon nanotubes in CNT arm. We demonstrate the actuation of the nanotweezer using the voltage calculated with the electrostatic force.

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SWCNT/Nafion Composite Development for Improvement of Mechanical Properties of IPMC (IPMC의 기계적 특성향상을 위한 SWCNT/Nafion 복합체 개발)

  • Kwon, Hui-June;Lee, Heon-Sang;Lee, Jung-Hwa;Jun, Chan-Bong;Kang, Jung-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.1
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    • pp.47-53
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    • 2011
  • From recent research, it has revealed that Electroacitve polymer(EAP) has a physical limitation. Carbon nanotube(CNT) is known as the promising material which has excellent electro-mechanical characteristics and is mostly defect-free. It is expected that a successful synthesis of CNT and Nafion known as a primary material for IPMC would make a great improvement on its electro-mechanic feature. In this paper, we suggest the method of synthesis of CNT with Nafion which improves electro-mechanical characteristic. Using mechanical dispersion with Nafion and Isopropyl Alcohol(IPA), we disperse Single-walled carbon nanotubes(SWCNT). For a uniformly layer of CNT, we used a spray gun on a hot plate by a simplified method. In the result, we fabricated a disperse SWCNT/Nafion composite uniformly.

Investigation of Electrostatic Force in Carbon Nanotube for the Analysis of Nonlinear Dynamic Behavior (카본 나노 튜브의 동역학 거동 해석에 필요한 정전기력 연구)

  • Lee J.K.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.840-843
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    • 2005
  • For an analysis of nonlinear dynamic behavior in carbon nanotube(CNT) an electrostatic force of CNT was investigated. The boundary condition in the CNT was assumed to clamped-clamped case at both ends. This type of CNT is widely used as micro and nano-sensors. For larger gaps in between sensor and electrode the van der Waals force can be ignored. The electrostatic force can be expressed as linear form using Taylor series. However, the first term of the series expansion was investigated here. The electrostatic force From this study we can conclude that for larger gaps the electrostatic force play an important role in determining the deflections as well as the pull-in voltage of simply supported switches.

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Field emission properties of tip-type carbon nanotube emitters with substrate interlayer (기판 삽입층을 갖는 팁 구조 탄소 나노튜브 이미터의 전계방출 특성)

  • Chang, Han-Beet;Kim, Jong-Pil;Kim, Bu-Jong;Park, Jin-Seok
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1410-1411
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    • 2011
  • Tip-type carbon nanotube(CNT) based electron emitters were fabricated by forming a hafnium(Hf) interlayer between the CNT and the substrate. The CNTs were deposited by using the electrophoretic deposition method and thermally treated. No significant change in the microscopic structure of the CNTs, such as the ratio of length to diameter, was observed after the deposition of Hf interlayer and thermal treatment. As compared with the CNT emitter without the Hf-interlayer and thermal treatment, the CNT emitter with the Hf-interlayer and thermal treatment showed noticeably improved electron-emission properties due to the enhanced adhesion.

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Nano Visual Servoing Loop Using SEM Image (전자현미경 영상을 이용한 나노 비주얼 서보잉)

  • Choi, Jin-Ho;Ahn, Sang-Jung;Park, Byong-Chon;Lyou, Joon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.10
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    • pp.1876-1882
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    • 2008
  • Nano manipulator is used to manufacture Carbon NanoTube(CNT) tips. Using nano manipulator, operator attaches a CNT at the apex of Atomic Force Microscope(AFM) tip, which requires a mastery of mechanics and long manufacture time. Nano manipulator is installed inside a Scanning Electron Microscope(SEM) chamber to observe the operation. This paper presents a control scheme for horizontal axes of nano manipulator via processing SEM image. Edges of AFM tip and CNT are first detected, and the position information so obtained is fed to control horizontal axes of nano manipulator. That is, a visual servoing loop is realized to control the axes more precisely in nano scale.

A Study on the Property of Semiconductive Shield Composite through Karl Fischer Method in Power Cable (Karl Fischer를 통한 전력케이블용 반도전 Composite 특성 연구)

  • Yang, Hoon;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.187-188
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    • 2008
  • In this paper, we have investigated water content of semiconductive shield materials for power cables, EEA(Ethylene Ethyl Acrylate) is used polymer matrix. And filler is used CNT(Carbon Nanotube) and CB(Carbon Black). EEA, CNT and CB is favor moisture. In case of EEA, it has polyolefin resin that strong polarity combination. To research water content, experimental method used KF(Karl Fischer). KF method is Electrochemical titration based on chemical reaction. As a result, specification by KEPCO(Korea Electric Power Corporation) is lower than 800ppm. CNT and CB ratio of 80 versus 20 is best specimen that had lowest moisture content. It seem likely to increase crosslinking rate, CNT between CB.

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Nonlinear forced vibrations of multi-scale epoxy/CNT/fiberglass truncated conical shells and annular plates via 3D Mori-Tanaka scheme

  • Mirjavadi, Seyed Sajad;Forsat, Masoud;Barati, Mohammad Reza;Hamouda, AMS
    • Steel and Composite Structures
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    • v.35 no.6
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    • pp.765-777
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    • 2020
  • In the context of classic conical shell formulation, nonlinear forced vibration analysis of truncated conical shells and annular plates made of multi-scale epoxy/CNT/fiberglass composites has been presented. The composite material is reinforced by carbon nanotube (CNT) and also fiberglass for which the material properties are defined according to a 3D Mori-Tanaka micromechanical scheme. By utilizing the Jacobi elliptic functions, the frequency-deflection curves of truncated conical shells and annular plates related to their forced vibrations have been derived. The main focus is to study the influences of CNT amount, fiberglass volume, open angle, fiber angle, truncated distance and force magnitude on forced vibrational behaviors of multi-scale truncated conical shells and annular plates.