• 제목/요약/키워드: Nano-Wall

검색결과 167건 처리시간 0.027초

A study of static characteristics of New gas mixture in AC-PDP

  • Kwon, Shi-Ok;Kim, Ji-Sun;Joung, Bong-Kyu;Hwang, Ho-Jung
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
    • /
    • pp.1191-1194
    • /
    • 2005
  • The effects of addition of $D_2$ to conventional gases on the discharge characteristics were investigated in this work with the aim of improving the voltage margin, the wall charge and the jitter. The addition of an extremely small gas-inlet amounts of $D_2$ increased the number of electrons which improves the $Xe^{\ast}$ density and $Xe_2^{\ast}$ density. As a result, the voltage margin, the jitter and the wall charge increased.

  • PDF

Measurement of Brownian motion of nanoparticles in suspension using a network-based PTV technique

  • Banerjee A.;Choi C. K.;Kihm K. D.;Takagi T.
    • 한국가시화정보학회:학술대회논문집
    • /
    • 한국가시화정보학회 2004년도 Proceedings of 2004 Korea-Japan Joint Seminar on Particle Image Velocimetry
    • /
    • pp.91-110
    • /
    • 2004
  • A comprehensive three-dimensional nano-particle tracking technique in micro- and nano-scale spatial resolution using the Total Internal Reflection Fluorescence Microscope (TIRFM) is discussed. Evanescent waves from the total internal reflection of a 488nm argon-ion laser are used to measure the hindered Brownian diffusion within few hundred nanometers of a glass-water interface. 200-nm fluorescence-coated polystyrene spheres are used as tracers to achieve three-dimensional tracking within the near-wall penetration depth. A novel ratiometric imaging technique coupled with a neural network model is used to tag and track the tracer particles. This technique allows for the determination of the relative depth wise locations of the particles. This analysis, to our knowledge is the first such three-dimensional ratiometric nano-particle tracking velocimetry technique to be applied for measuring Brownian diffusion close to the wall.

  • PDF

EFFECT OF THE WATER-WALL INTERACTION POTENTIALS ON THE PROPERTIES OF AQUEOUS SOLUTIONS CONFINED WITHIN A UNIFORMLY CHARGED NANO-CHANNEL

  • Hoang, H.;Kang, S.;Suh, Y.K.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2009년 춘계학술대회논문집
    • /
    • pp.368-376
    • /
    • 2009
  • Studies on the effect of the wall-ion, wall-water, water-ion and ion-ion interaction on properties of water and ions in nano-channels have been performed through the use of different kinds of ions or different models of potential energy between wall-ion or wall-water. On this paper, we address the effect of water-wall interaction potential on the properties of confined aqueous solution by using the molecular dynamics (MD) simulations. As the interaction potential energies between water and wall we employed the models of the Weeks-Chandler-Andersen (WCA) and Lennard-Jones (LJ). On the MD simulations, 680 water molecules and 20 ions are included between uniformly charged plates that are separated by 2.6 nm. The water molecules are modeled by using the rigid SPC/E model (simple point charge/Extended) and the ions by the charged Lennard-Jones particle model. We compared the results obtained by using WCA potential with those by LJ potential. We also compared the results (e.g. ion density and electro-static potential distributions) in each of the above cases with those provided by solving the Poisson-Boltzmann equation.

  • PDF

Room Temperature Ferromagnetism on Co and Fe Doped Multi-wall Carbon Nano-tube

  • Chae, K.H.;Gautam, S.;Yu, B.Y.;Song, J.H.;Augustine, S.;Kang, J.K.;Asokan, K.
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
    • /
    • pp.171-171
    • /
    • 2011
  • Co and Fe doped multi-wall carbon nano-tubes (MWCNTs) synthesized by microwave plasma enhanced chemical vapor deposition (PECVD) technique are investigated with synchrotron radiations at Pohang Light Source (PAL) and European Synchrotron Radiation Facility (ESRF). Near edge x-ray absorption spectroscopy (NEXAFS) measurement at C K, Co $L_{3,2}$ and Fe $L_{3,2}$-edges, and x-ray magnetic circular dichroism (XMCD) at Co and Fe $L_{3,2}$-edges have been carried at 7B1 XAS KIST and 2A MS beamline, respectively, to understand the electronic structure and responsible magnetic interactions at room temperature. X-ray absorption spectroscopy (XAS) at C K-edge shows significant p-bonding and Co and Fe L-edges proves the presence of $Co^{2+}$ and $Fe^{2+}$ in octahedral symmetry. Co and Fe doped MWCNTs show good XMCD spectra at 300K. The effect on the magnetism is also studied through swift heavy ion (SHI) radiations and magnetism is found enhanced and change in the electronic structure in Co-CNTs is investigated.

  • PDF

전자빔 증발법 박막 증착을 이용한 양극 산화 알루미늄 템플릿의 나노 포어 가공 연구 (Study on the narrowed nanopores of anodized aluminum oxide template by thin-film deposition using e-beam evaporation)

  • 이승훈;이민영;김천중;김관오;윤재성;유영은;김정환
    • 한국표면공학회지
    • /
    • 제54권1호
    • /
    • pp.25-29
    • /
    • 2021
  • The fabrication of nanopore membrane by deposition of Al2O3 film using electron-beam evaporation, which is fast, cost-effective, and negligible dependency on substance material, is investigated for potential applications in water purification and sensors. The decreased nanopore diameter owing to increased wall thickness is observed when Al2O3 film is deposited on anodic aluminum oxide membrane at higher deposition rate, although the evaporation process is generally known to induce a directional film deposition leading to the negligible change of pore diameter and wall thickness. This behavior can be attributed to the collision of evaporated Al2O3 particles by the decreased mean free path at higher deposition rate condition, resulting in the accumulation of Al2O3 materials on both the surface and the edge of the wall. The reduction of nanopore diameter by Al2O3 film deposition can be applied to the nanopore membrane fabrication with sub-100 nm pore diameter.

Quantitative Evaluation of Non-Carbon Content in the Single Wall Carbon Nanotube Soot using Thermogravimetric Analysis

  • Han, J.H.;An, K.H.;Lee, N.S.;Goak, J.C.;Jeong, M.S.;Choi, Y.C.;Oh, K.H.;Kim, K.K.;Lee, Y.H.
    • Carbon letters
    • /
    • 제10권1호
    • /
    • pp.5-8
    • /
    • 2009
  • We measured the non-carbon content of single-walled carbon nanotubes (SWCNTs) in SWCNT soot using thermogravimetric analysis. The weight increased percentage by the oxidation of metal in the raw soot is well obtained by TGA graph which was confirmed with ICP-AES, XRD, and XPS. This work will be very useful for the purity precise evaluation of SWCNT with UN-vis-NIR spectroscopy.

원자간력 현미경 탄소 나노튜브 팁을 이용한 플러렌 나노 구조물 제작에 관한 분자동역학 시뮬레이션 (Molecular Dynamics Simulations of Fullerene Nanostructure Fabrications by Atomic Force Microscope Carbon Nanotube tip)

  • 이준하;이홍주
    • 한국전기전자재료학회논문지
    • /
    • 제17권8호
    • /
    • pp.812-822
    • /
    • 2004
  • This paper shows that carbon nanotubes can be applied to a nanopipette. Nano space in atomic force microscope multi-wall carbon nanotube tips is filled with molecules and atoms with charges and then, the tips can be applied to nanopipette when the encapsulated media flow off under applying electrostatic forces. Since the nano space inside the tips can be refilled, the tips can be permanently used in ideal conditions of no chemical reaction and no mechanical deformation. Molecular dynamics simulations for nanopipette applications demonstrated the possibility of nano-lithography or single-metallofullerene-transistor array fabrication.

잉크젯 프린팅에 의한 단일벽 탄소나노튜브의 패터닝 (Patterning of Single-wall Carbon Nanotube using Ink-jet Printing)

  • 송진원;윤여환;한창수
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2007년도 제38회 하계학술대회
    • /
    • pp.236-237
    • /
    • 2007
  • A single-wall carbon nanotube (SWNT) transparent conductive film (TCF) was fabricated using a simple inkjet printing method. The TCF could be selectively patterned by controlling the dot size to diameters as small as 34${\mu}m$. In thisrepeatable and scalable process, we achieved 71% film transmittance and a resistance of 900 ohm/sq sheet with an excellent uniformity, about $\pm$5% deviation overall. Inkjet printing of SWNT is substrate friendly and the TCF is printed on a flexible substrate. This method of fabrication using direct printing permits mass production of TCF in a large area process, reducing processing steps and yielding low-cost TCF fabrications on a designated area using simple printing.

  • PDF

폴리카보실란으로부터 제조된 탄화규소 중공사의 미세구조제어 (Nano-Structure Control of SiC Hollow Fiber Prepared from Polycarbosilane)

  • 신동근;공은배;조광연;권우택;김영희;김수룡;홍준성;류도형
    • 한국세라믹학회지
    • /
    • 제50권4호
    • /
    • pp.301-307
    • /
    • 2013
  • SiC hollow fiber was fabricated by curing, dissolution and sintering of Al-PCS fiber, which was melt spun the polyaluminocarbosilane. Al-PCS fiber was thermally oxidized and dissolved in toluene to remove the unoxidized area, the core of the cured fiber. The wall thickness ($t_{wall}$) of Al-PCS fiber was monotonically increased with an increasing oxidation curing time. The Al-PCS hollow fiber was heat-treated at the temperature between 1200 and $2000^{\circ}C$ to make a SiC hollow fibers having porous structure on the fiber wall. The pore size of the fiber wall was increased with the sintering temperature due to the decomposition of the amorphous $SiC_xO_y$ matrix and the growth of ${\beta}$-SiC in the matrix. At $1400^{\circ}C$, a nano porous wall with a high specific surface area was obtained. However, nano pores grew with the grain growth after the thermal decomposition of the amorphous matrix. This type of SiC hollow fibers are expected to be used as a substrate for a gas separation membrane.