• Title/Summary/Keyword: Electron Microscopy

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Fabrication of Single Crystal Poly (3,4-ethylenedioxythiophene) Nanowire Arrays by Vapor Phase Polymerization with Liquid-bridge-mediated Nanotransfer Molding

  • 이기석;조보람;성명모
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.372-372
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    • 2012
  • We have studied a fabrication of Poly (3,4-ethylenedioxythiophene) (PEDOT) wire arrays and structures with various feature sizes from hundreds micrometers to tens nanometers. PEDOT is well-known as a conducting material, can be grown by a vapor pressure polymerization (VPP) method. The VPP technique is a bottom-up processing method that utilizes the organic arrangement of macromolecules to easily produce ordered aggregates. Also, liquid-bridge-mediated nanotransfer molding (LB-nTM), which was reported as a new direct patterning method recently, is based on the direct transfer of various materials from a mould to a substrate through a liquid bridge between them. The PEDOT nanowires grown by VPP method and transferred on a substrate to use LB-nTM method have been investigated by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED), X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and electrical properties.

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Switch-on Phenomena and Field Emission from Single-Walled Carbon Nanotubes Embedded in Glass

  • Daradkeh, Samer I.;Mousa, Marwan S.
    • Applied Microscopy
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    • 제47권3호
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    • pp.86-94
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    • 2017
  • In this study, we will describe a new design of carbon nanotubes tip. Single-walled carbon nanotubes produced using high-pressure CO over Fe particles (HiPCO) at CNI, Houston, TX used in this study. These tips were manufactured by employing a drawing technique using glass puller. Field electron microscopies with tips (cathode) to screen (Anode) separation of ~10 mm was used to characterize the electron emitters. The system was evacuated down to base pressure of (${\sim}10^{-8}$ mbar) when baked at up to (${\sim}200^{\circ}C$) over night. An electron field emission patterns, as well as current versus voltage characteristics and Fowler-Nordheim plots, are discussed.

Specimen Preparation for Scanning Electron Microscope Using a Converted Sample Stage

  • Kim, Hyelan;Kim, Hyo-Sik;Yu, Seungmin;Bae, Tae-Sung
    • Applied Microscopy
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    • 제45권4호
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    • pp.214-217
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    • 2015
  • This study introduces metal coating as an effective sample preparation method to remove charge-up caused by the shadow effect during field emission scanning electron microscope (FE-SEM) analysis of dynamic structured samples. During a FE-SEM analysis, charge-up occurs when the primary electrons (input electrons) that scan the specimens are not equal to the output electrons (secondary electrons, backscattered electrons, auger electrons, etc.) generated from the specimens. To remove charge-up, a metal layer of Pt, Au or Pd is applied on the surface of the sample. However, in some cases, charge-up still occurs due to the shadow effect. This study developed a coating method that effectively removes charge-up. By creating a converted sample stage capable of simultaneous tilt and rotation, the shadow effect was successfully removed, and image data without charge-up were obtained.

Technical Overview on the Electron Backscattered Diffraction Sample Preparation

  • Kim, Dong-Ik;Kim, Byung-Kyu;Kim, Ju-Heon
    • Applied Microscopy
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    • 제45권4호
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    • pp.218-224
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    • 2015
  • A technical overview on the various sample preparation methods for electron backscattered diffraction (EBSD) analysis is carried out. The mechanical polishing with colloidal silica finish, electro-chemical polishing, dual layer coating and ion beam milling are introduced for the common sample preparation methods for EBSD observation and some issues that are frequently neglected by the common EBSD users but should be considered to get a reliable EBSD data are discussed. This overview would be especially helpful to the people who know what EBSD technique is but do not get a reliable EBSD data because of difficulties in sample preparation.

Transparent MgO films deposited on glass substrates by e-beam evaporation for AC plasma display panels

  • Kumar, Sudheer;Premkumar, S.;Sarma, K.R.;Kumar, Satyendra
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.63-66
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    • 2004
  • Transparent MgO thin films were deposited on glass substrates by electron beam evaporation of MgO (99.99%) under $O_2$ atmosphere at 150-250 $^{\circ}C$. These films were characterized for their useful properties such as thickness, transmission, and refractive index using ultraviolet / visible (UV/VIS) spectrophotometer, scanning electron microscopy (SEM), and Spectroscopic Ellipsometry. The thickness of MgO films were measured by alpha step instrument and found to be 600 nm to 1000 nm and are meeting the stoichiometry. The transmission spectrum of these films shows transmittance values ${\sim}$92%..

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논우렁이 촉수(觸手) 칼라세포(Collar Cell)의 미세구조(微細構造)에 관한 연구(硏究) (The Fine Structure of Collar Cell in Tentacles of Chinese Mystery Snail, Cipangopaludina chinensis malleata Reeve)

  • 송용직;김우갑;김창환
    • Applied Microscopy
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    • 제17권2호
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    • pp.23-30
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    • 1987
  • There are groups of large monopolar cells containing numerous secretory inclusions in the muscular and connective tissue. These cells contain the electron-lucent vesicles in the size of $0.5{\sim}0.9{\mu}m$, which are secreted to the exterior of the tentacle through their cytoplasmic processes projected to the epithelial layer. Secretory material can be seen accumulating in swollen portions of the granular endoplasmic reticulum. It is postulated that this material is transported to the Golgi-complex and thus the limiting membrane of the inclusions is derived from the Golgi-membrane. An electron lucent material secreted from these cells seems to be similar to fibrous electron lucent material filled in the brush border of the epidermis.

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수종(數種) Rhizobium의 편모에 대한 전자현미경적(電子顯微鏡的) 관찰(觀察) (Electron Microscopical Observation on the Flagella of Several Species of the Genus Rhizobium)

  • 안경준;이웅직
    • Applied Microscopy
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    • 제8권1호
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    • pp.9-15
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    • 1978
  • Five strains of the Genus Rhizobium were isolated from the nodules of five leguminous plants respectively. They were identified according to Bergey's Manual together with the results of Vincent. The flagella of each strains were observed by electron microscope using negative staining with PTA and metal shadowing with chromium. Five host plants and identified Rhizobium strains were as. follows. Pisum sativum.....R. leguminosarum Phaseolus vulgaris.....R. phaseoli Trifolium repens.....R. trifolii Glycine max.....R. japonicum Lupinus grandiflorus.....R. lupini Electron micrographs showed that R. leguminosarum and R. phaseoli had 4 peritrichous flagella, where as R. trifolii had 5 peritrichous flagella. On the other hand, R. japonicum and R. lupini had 1 subpolar flagellum.

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Improvement of Alignment Accuracy in Electron Tomography

  • Jou, Hyeong-Tae;Lee, Sujeong;Kim, Han-Joon
    • Applied Microscopy
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    • 제43권1호
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    • pp.1-8
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    • 2013
  • We developed an improved method for tilt series alignment with fiducial markers in electron tomography. Based on previous works regarding alignment, we adapted the Levenberg-Marquardt method to solve the nonlinear least squares problem by incorporating a new formula for the alignment model. We also suggested a new method to estimate the initial value for inversion with higher accuracy. The proposed approach was applied to geopolymers. A better alignment of the tilt series was achieved than that by IMOD S/W. The initial value estimation provided both stability and a good rate of convergence since the new method uses all marker positions, including those partly covering the tilt images.

위 황색종의 광학 및 전자현미경적 관찰 (Light and electron microscopic studies of a gastric xanthoma)

  • 권태정;김정숙;문영명
    • Applied Microscopy
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    • 제11권1호
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    • pp.21-28
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    • 1981
  • Gastric xanthoma which is not a true neoplasm and clinically insignificant consists of the small yellowish lesion of the gastric mucosa, frequently of multiple occurrence. Histologically the lesion shows chronic superficial gastritis with intestinal metaplasia and occasional collections of foam cells within the lamina propria. Electron microscopically. the xanthoma, cells are composed of. lipid-laden histiocytes with. many autophagocytic Iysosomes surrounding the cytoplasmic lipid vacuoles. Many residual bodies are also noted. The pathogenesis of the gastric xanthoma is obscure, however it is thought that a previous focal lesion of the gastric mucosa may have been a factor. One case of gastric xanthoma is reported here and a brief review of literature is also made.

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HU-125C 전자현미경에 있어서 카메라 상수의 변화 및 상의 회전에 대한 조사 (Variation of Camera Constant and Image Rotation in HU-125C Electron Microscope)

  • 최주;예길촌
    • Applied Microscopy
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    • 제4권1호
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    • pp.1-4
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    • 1974
  • Hitachi HU-125C 전자현미경에 있어서 각 렌즈 전류의 연동에 따른 카메라 상수의 변화를 주사하였다. 시료의 높이 변화가 카메라 상수의 변동에 현저한 영향을 끼치고 있음도 알 수 있었다. 전자회절상과 시편상의 회전은 결정시료를 사용하여 측정하였다. 금속박막을 조사연구함에 있어서 전자현미경의 실제석인 조작방안을 적정화하기 위한 몇 가지 문제를 조사하였다. 본 실험진행을 전자현미경 작업을 통하여 크게 도와 준 김수철씨에게 진심으로 감사드립니다.

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