• 제목/요약/키워드: Nano-tube

검색결과 275건 처리시간 0.026초

전자파 흡수체를 위한 전도성 소재로서의 탄소나노소재의 특성에 대한 연구 (A Study on Carbon Nano Materials as Conductive Oilers for Microwave Absorbers)

  • 이상관;김천곤;김진봉
    • Composites Research
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    • 제19권5호
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    • pp.28-33
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    • 2006
  • 본 논문에서는 카본 블랙, 탄소나노섬유, 탄소나노튜브를 혼합한 유리섬유/에폭시 복합재료 적층판의 복소 유전율과 그 특성이 전자파 흡수체 설계에 미치는 영향에 대한 연구를 수행하였다. 실험은 벡터회로망분석기와 7 mm 동축관을 이용하여 0.5 GHz$\sim$18 GHz의 주파수 영역에서 수행하였다. 실험결과는 복합재료의 복소 유전율이 첨가된 탄소나노소재의 함유율과 그 특성에 강하게 영향을 받는 것으로 나타났다. 복소 유전율의 실수부와 허수부는 탄소나노소재의 함유량에 따라 증가하지만, 탄소나노소재의 형태에 따라서 그 증가율이 모두 다르게 나타났다. 이러한 상이한 증가율은 단층형 흡수체의 설계에 있어서 두께에 영향을 준다. 이러한 영향은 단층형 흡수체를 설계하기 위한 복소 유전율의 해와 실험으로부터 얻은 세가지 종류의 복합재료의 복소 유전율을 함께 배치한 Cole-Cole 선도를 이용하여 평가되었다. 설계결과를 바탕으로 각각의 탄소나노소재를 이용하여 -10 dB의 흡수대역이 모두 3 GHz이면서 두께가 서로 다른 흡수체를 개발하였다.

배리어 유전체 방전을 이용한 전기 집진부에서의 나노 입자 집진 효율 (Collection Efficiency of Nano Particles by Electrostatic Precipitator using Dielectric Barrier Discharge)

  • 강석훈;지준호;변정훈;황정호
    • 대한기계학회논문집B
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    • 제27권11호
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    • pp.1542-1547
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    • 2003
  • Although dielectric barrier discharge (DBD) in air has been applied to a wider range of aftertreatment processes for HAPs (Hazardous Air Pollutants), due to its high electron density and energy, its potential use as precharging dust particles is not well known. In this work, we measured size distributions of bimodal aerosol particles and estimated collection efficiency of the particles by an electrostatic precipitator (ESP) using DBD as particle charger. To examine the particle collection with DBD charger, nano size particles of NaCl(20∼100nm) and DOS (50∼500nm) were generated by a tube furnace and an atomizer, respectively. For experimental conditions of 60㎐, 11㎸ and 60 lpm, the particle collection efficiency for the hybrid system was over 85%, based on the number of particles captured.

첨단 유동가시화 기법들과 Blue Ocean 전략 (Advanced Flow Visualization Technologies and Blue Ocean Strategy)

  • 이상준
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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    • pp.145-146
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    • 2006
  • Recently, the next-generation advanced flow visualization techniques such as holographic PIV, dynamic PIV, echo-PIV, micro/nano-PIV, and X-ray PIV have been introduced. These advanced measurement techniques have a big potential as the core technology for analyzing outmost thermo-fluid flows in future. These would be indispensable in solving complicated thermo-fluid flow problems not only in the industrial fields such as automotive, space, electronics, aero- and hydro-dynamics, steel, and information engineering, but also in the research fields of medical science, bio-medical engineering, environmental and energy engineering etc. Especially, NT (Nano Technology) and BT (Bio Technology) strongly demand these advanced measurement techniques, because it is impossible for conventional measurement methods to observe most complicated nano- and bio-fluidic phenomena. In this presentation, the basic principle of these high-tech flow visualization techniques and their practical applications which cannot be resolved by conventional methods, such as blood flows in a micro-tube, in vivo analysis of micro-circulation, and flow around a living body will be introduced as a blue ocean strategy.

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배리어 유전체 방전을 이용한 전기 집진부에서의 나노 입자 집진 효율 (Collection Efficiency of Nano Particles by Electrostatic Precipitator using Dielectric Barrier Discharge)

  • 강석훈;변정훈;지준호;황정호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1435-1440
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    • 2003
  • Although Dielectric Barrier Discharge (DBD) in air has been applied to a wider range of aftertreatment processes for HAPs(Hazardous Air Pollutants), due to its high electron density and energy, its potential use as precharging dust particles is not well known. In this work, we measured size distributions of bimodal aerosol particles and estimated collection efficiency of the particles by electrostatic precipitator(ESP) using DBD as particle charger. To examine the particle collection with DBD charger, nano size particles of NaCl($20{\sim}100$ nm) and DOS($50{\sim}800$ nm) were generated by tube furnace and atomizer, respectively. For experimental conditions of 60 Hz, 11 kV, and 60 lpm, the particle collection efficiency for the hybrid system comprising DBD charger and ESP was over 85 %, based on the number of particles captured.

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첨단 유동가시화 기법들과 Blue Ocean 전략 (Advanced Flow Visualization Technologies and Blue Ocean Strategy)

  • 이상준
    • 한국가시화정보학회지
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    • 제4권2호
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    • pp.3-5
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    • 2006
  • Recently, the next-generation advanced flow visualization techniques such as holographic PIV, aynni.c PIV, echo-PIV, micro/nano-PIV, and X-ray PIV have been introduced. These advanced mea-surement techniques have a big potential as the core technology for analyzing outmost thermo-fluid flows in future. They would be indispensable in solving complicated thermo-fluid flow problems not only in industrial fields such as automotive, space, electronics, aero- and hydro-dynamics. steel, and information engineering, but also in the research fields of medical science, bio-medical engineering, environmental and energy technology etc. Especially, NT (Nano Technology) and BT (Bio Technology) strongly demand these advanced measurement techniques, because it is impossible for conventional measurement methods to observe the nano- and bio-fluidic flow phenomena. In this article, the basic principle of these high-tech flow visualization techniques and their practical applications which cannot be resolved by conventional methods, such as blood flows in a micro-tube, in vivo analysis of micro-circulation, and flow around a living body are introduced as a blue ocean strategy.

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유전체 베리어 방전형 2단 전기집진기의 인가전압 파형별 나노 및 서브마이크론 입자 집진 특성 (Nano and Submicron Sized Particle Collection with Various Voltage Waveforms for Dielectric Barrier Discharge Type 2-Stage ESP)

  • 박재홍;변정훈;황정호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1261-1266
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    • 2004
  • Dielectric Barrier Discharge (DBD) in air, which has been established for the production of large quantities of ozone, is more recently being applied to a wider range of aftertreatment processes for HAPs (Hazardous Air Pollutants). Although DBD has high electron density and energy, its potential use as precharging nano and submicron particles are not well known. In this work, we measured I-V characteristics of DBD and estimated collection efficiency of the particles by DBD type 2-stage ESP. To examine the particle collection with various applied voltage waveforms of DBD for nano and submicron sized, bimodal particles were generated by a electrical tube furnace and an atomizer.

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Effects of mixed contents of carbon nanoreinforcements on the impact resistance of epoxy-based nanocomposites

  • Ayatollahi, M.R.;Naeemi, A.R.;Alishahi, E.
    • Structural Engineering and Mechanics
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    • 제56권2호
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    • pp.157-167
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    • 2015
  • The impact behavior of epoxy-based nanocomposites reinforced with carbon nano tube (CNT), carbon nano fiber (CNF) and mixed contents of these nanoparticles was investigated using Izod impact test. The results showed that while the impact strength of nanocomposites containing 1 wt% of CNT and 1 wt% of CNF increased 19% and 13% respectively, addition of mixed contents of these nanofillers (0.5-0.5 wt%) demonstrated higher improvement (21%) in the impact resistance. The trend of the results is explained on the basis of different fracture mechanisms of nanocomposites. Furthermore, the fracture surface of specimens and the dispersion state of nanoenhancers have been studied using scanning electron microscopy (SEM) photographs.

질화붕소 나노피포드 기반 나노분자 메모리 시스템

  • Lee Jun-Ha;Lee Hoong-Joo;Kwon Oh-Keun;Byun Ki-Ryang;Kang Jeong-won
    • 한국반도체및디스플레이장비학회:학술대회논문집
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    • 한국반도체및디스플레이장비학회 2005년도 추계 학술대회
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    • pp.31-34
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    • 2005
  • 분자 위치제어 메모리 시스템에 대하여 고전적인 분자동역학을 이용하여 결합에너지 및 다양한 외부전압의 형태에 따른 셔틀 풀러렌 동작에 관하여 연구하였다. 단일 나노피포드 형(single-nanopeapod type)은 질화붕소 나노튜브(boron-nitride nano tube) 속에 세 개의 엔도풀러렌(endo-fullerene)과 양쪽 끝에 구리 전극이 채워져 있는 구조를 갖고 있는 구조를 갖고 있다. 결론적으로, 분자동역학 시뮬레이션 결과로부터 이 나노메모리 시스템은 비휘발성임을 알 수 있었다. 안정적인 bit 변화를 위해서는 단일 나노피포드 형은 0.1 eV/$\AA$ 외부전압이 필요로 함을 알 수 있었다.

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