• Title/Summary/Keyword: Scanning Electron Microscope

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Possibility of cementation of soft soil using Bacteria (Bacteria를 이용한 연약한 흙의 고결화 가능성)

  • Kim, Dae-Hyeon;Kim, Ho-Chul;Park, Kyoung-Ho
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.379-391
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    • 2010
  • In order to understand the mechanism of cementation of soft soils treated with bacteria, three types of specimens(untreated, normal bacteria concentration treated, and high bacteria concentration treated) were made. Scanning Electron Microscope(SEM), EDX and X-ray diffraction(XRD) analyses were performed on the soft silt and loose sand specimens. Compared with the untreated specimen, a clearer cementation between particles was observed in the high bacteria concentration treated specimen. Based on the scanning electron microscope(SEM) EDX analyses, more calcium carbonate was observed in the specimen treated with high bacteria concentration than other specimens. On the basis of the preliminary results, it appears that microbial cementation can occur in the soft soil. Further study on the cementation of soils using bacteria is necessary to validate this result.

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Establishment of Column Unit for Electron Beam Machining System (전자빔 가공시스템용 경통의 구축)

  • 강재훈;이찬홍;최종호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.1017-1020
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    • 2004
  • It is not efficient and scarcely out of the question to use commercial expensive electron beam lithography system widely used for semiconductor fabrication process for the manufacturing application field of various devices in the small business scope. Then scanning electron microscope based electron beam machining system is maybe regarded as a powerful model can be used for it simply. To get a complete suite of thus proper system, column unit build up with several electo-magnetic lens is necessarily required more than anything else to modify scanning electron microscope. In this study, various components included several electro-magnetic lens and main body which are essentially constructed for column unit are designed and manufactured. And this established column unit will be used for next connected study in the development step of scanning electron microscope based electron beam machining system.

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Analysis of Ceramics Using Scanning Electron Microscopy (주사전자현미경을 활용한 세라믹의 분석)

  • Lee, Sujeong
    • Ceramist
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    • v.22 no.4
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    • pp.368-380
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    • 2019
  • A ceramic is used as a key material in various fields. Accordingly, the use of scanning electron microscopy is increased for the purpose of evaluating the reliability and defects of advanced ceramic materials. The scanning electron microscope is developed to overcome the limitations of optical microscopy and uses accelerated electrons for imaging. Various signals such as SE, BSE and characteristic X-rays provide useful information about the surface microstructure of specimens and, the content and distribution of chemical components. The development of electron guns, such as FEG, and the improved lens system combined with the advanced in-lens detectors and STEM-in-SEM system have expanded the applications of SEM. Automated SEM-EDS analysis also greatly increases the amount of data, enabling more statistically reliable results. In addition, X-ray CT, XRF, and WDS, which are installed in scanning electron microscope, have transformed SEM a more versatile analytical equipment. The performance and specifications of the scanning electron microscope to evaluate ceramics were reviewed and the selection criteria for SEM analysis were described.

DIMENSIONAL STABILITY AND SURFACE MORPHOLOGY OF VARIOUS DENTURE RESINS (의치상 레진의 중합 방법에 따른 크기의 안정성 및 표면 형태에 관한 연구)

  • Chae Sook-Young;Vang Mong-Sook
    • The Journal of Korean Academy of Prosthodontics
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    • v.30 no.3
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    • pp.401-410
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    • 1992
  • The purpose of this study was to investigate the dimensional changes and surface morphology of dentures processed by various polymerization conditions. The measurements were done by taking radiograph and using vernier calipers and each specimen was observed on scanning electron microscope. Results obtained were as follows. 1. The difference of dimensional stability was not recognized between various polymerization conditions(heat-cured resin, pour-type resin, microwave-cured resin, and injection molding resin). 2. There were expansion and shrinkage in the occlusal dimension, shrinkage in the frontal dimension, and expansion in the lateral dimension. 3. Scanning electron microscope pictures of heat-cured resin showed dense and regular surface morphology. 4. Microwave-cured resin surface appeared more regular and smooth than pour-type resin but less dense and more irregular than heat-cured resin. 5. Scanning electron microscope pictures of pour-type resin with the lowest dimensional change showed the most irregular surface morphology.

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Focused ion beam-scanning electron microscope examination of high burn-up UO2 in the center of a pellet

  • Noirot, J.;Zacharie-Aubrun, I.;Blay, T.
    • Nuclear Engineering and Technology
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    • v.50 no.2
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    • pp.259-267
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    • 2018
  • Focused ion beam-scanning electron microscope and electron backscattered diffraction examinations were conducted in the center of a $73\;GWd/t_U\;UO_2$ fuel. They showed the formation of subdomains within the initial grains. The local crystal orientations in these domains were close to that of the original grain. Most of the fission gas bubbles were located on the boundaries. Their shapes were far from spherical and far from lenticular. No interlinked bubble network was found. These observations shed light on previous unexplained observations. They plead for a revision of the classical description of fission gas release mechanisms for the center of high burn-up $UO_2$. Yet, complementary detailed observations are needed to better understand the mechanisms involved.

Analysis of Damaged Instance and Forming Fault for Disc Part in Automotive Steel Wheel (자동차용 스틸휠 디스크부품의 성형불량 및 파손사례분석)

  • Lee, Sung-Hee;Kim, M.Y.;Kim, T.G.;Yun, H.Y.;Kang, S.W.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.234-238
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    • 2006
  • In this research, an analysis of damaged instance and forming fault for disc part in automotive steel wheel was performed. Rolled steel material, which had been used in the manufacturing of the damaged disc part, was prepared for tensile test, quantitative analysis of chemical component and acquirement of scanning electron microscope images. Although the results of mechanical properties and chemical component ratio for the material satisfied the suggested specification, some material inherent problem was found in the scanning electron microscope images. Finally, in an analysis of chemical component for the damaged disc part used in road condition, mismatching of chemical component ratio between the suggested specification and test result was found.

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Plasma Diagnosis by Using Scanning Electron Microscope and Neural Network (신경망과 주사전자현미경을 이용한 플라즈마 진단)

  • Bae, Jung-Gi;Kim, Byung-Whan
    • Proceedings of the KIEE Conference
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    • pp.96-98
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    • 2006
  • A new ex-situ model to diagnose a plasma processing equipment was presented. The model was constructed by combining wavelet, scanning electron microscope, ex-situ measurement of etching profile, and neural network. The diagnosis technique was applied to a tungsten etching process, conducted in a $SF_6$ helicon plasma. The wavelet was used to characterize detailed variations of plasma-etched surface. The diagnosis model was constructed with the vertical wavelet component. For comparison, a conventional model was built by using the estimated profile data. Compared to the conventional model, the wavelet-based model, demonstrated a much improved diagnosis.

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A Study on the Ignition and Molten Mark Analysis of Ballast for Fluorescent Lamp (형광등용 안정기의 발화 및 용융흔 분석에 관한 연구)

  • 최충석;박창수;김혁수;김향곤;정재희
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • pp.173-177
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    • 1998
  • In this paper, we reported an outbreak of fire hazard of ballast for fluorescent lamp. The surface structure and composition of ballast coil analyzed by using metallurgical microscope, scanning electron microscope(SEM) and energy dispersive x-ray spectroscopy(EDX). The surface of molten mark appeared columnar structure and void. EDX analysis indicated that the molten mark spectra were composed not only of the corresponding original spectra but also of several new lines.

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