• Title/Summary/Keyword: Scanning Electron Microscope

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A Study on the Residual Stress and Microstructure of Autofrettaged SCM440 High Strength Steel (자긴가공된 SCM440 고강도강의 잔류응력 및 미세구조 분석에 관한 연구)

  • Kim, J.H.;Shim, W.S.;Lee, Y.S.;Cha, K.U.;Hong, S.K.
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.311-316
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    • 2008
  • Thick-walled cylinders, such as a cannon or nuclear reactor, are autofrettaged to induce advantageous residual stresses into pressure vessels and to increase operating pressure and the fatigue lifetimes. As the autofrettage level increases, the magnitude of compressive residual stress at the bore also increases. The purpose of the present paper is to predict the accurate residual stress of SCM440 high strength steel using the Kendall model which was adopted by ASME Code. Hydraulic pressure process was applied and thick-walled cylinders were autofrettaged up to 30% overstrain levels. Electro polishing was performed to get more accurate data. Residual stresses were measured by X-ray diffraction method. The autofrettaged surface which was plastically deformed analyzed using a scanning electron microscope(SEM). Although there were some differences in measured residual stress and numerical, there is a tendency to agree.

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Relationship of the Distribution Thickness of Dielectric Layer on the Nano-Tip Apex and Distribution of Emitted Electrons

  • Al-Qudah, Ala'a M.;Mousa, Marwan S.
    • Applied Microscopy
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    • v.46 no.3
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    • pp.155-159
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    • 2016
  • This paper analyses the relationship between the distribution of a dielectric layer on the apex of a metal field electron emitter and the distribution of electron emission. Emitters were prepared by coating a tungsten emitter with a layer of epoxylite resin. A high-resolution scanning electron microscope was used to monitor the emitter profile and measure the coating thickness. Field electron microscope studies of the emission current distribution from these composite emitters (Tungsten-Clark Electromedical Instruments Epoxylite resin [Tungsten/CEI-resin emitter]) have been carried out. Two forms of image have been observed: bright single-spot images, thought to be associated with a smooth substrate and a uniform dielectric layer; and multi-spot images, though to be associated with irregularity in the substrate or the dielectric layer.

Manufacture and Performance Estimation of Electron Detector for SEM (SEM용 전자검출기의 제작 및 성능평가)

  • Kim, Ji-Won;Jeon, Jong-Up;Boo, Kyeung-Seok
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1282-1287
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    • 2007
  • The nature of the signal collected by an SEM(Scanning Electron Microscope) in order to form images are all dependent on the detector used to collect them, and the quality of an acquired images is strongly influenced by detector performance. Therefore, the development of detector with high performance is very important for improving on the resolution of SEM. This paper presents the manufacture of secondary electron detector and the optimal position of electron detector through numerical analysis in SEM.

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Design and Control of Mini-Scanning Electron Microscope (미니형 주사전자 현미경의 설계 및 제어)

  • Park, Man-Jin;Kim, Dong-Hwan;Kim, Young-Dae;Jang, Dong-Young;Han, Dong-Chul
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1271-1276
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    • 2007
  • The most powerful analytical equipment usually comes at the cost of having the highest demand for space. Where electron microscopes has traditionally required a room to themselves, not just for reasons of their size but because of ancillary demands for pipes and service. The simple optical microscopes, of course, can occupy the desk-top, but because their performance is limited by the wavelength of light, their powers of magnification and resolution are inferior to that of the electron microscope. Mini SEM will sit comfortably on a desk-top but offers magnification and resolution performances much closer to that of a standard SEM. This new technique extends the scope of SEM as a high-resolution microscope, relatively cheap and widely available imaging tool, for a wider variety of samples.

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The Effect of Anionic Surfactants in Synthesizing Silicone Dioxide/Acrylate Core-Shell Polymer (이산화규소/아크릴계 유기물의 코어-셀 합성에서 음이온 계면활성제의 영향)

  • Kim, Duck-Sool;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.26 no.2
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    • pp.199-204
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    • 2009
  • Silicone dioxide absorbed polyoxyethylene alkylether sulfate (EU-S133D) surfactant was prepared. Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using Acrylate as a shell monomer and potassium persulfate (KPS) as an initiator. We found that when Acrylate core prepared by adding 2.0 wt% EU-S133D, silicone dioxide/Acrylate core-shell polymerization was carried out on the surface of silicone dioxide particle without forming the new silicone dioxide particle during acrylate shell polymerization in the inorganic/organic core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer and morphology of latex by scanning electron microscope(SEM).

Synthesis of Inorganic/Organic Core-Shell Polymer Using Polyoxyethylene Alkylether Sulfate as a Surfactant (Polyoxyethylene Alkylether Sulfate 계면활성제를 사용한 무기/유기 코어-셀의 합성)

  • Kim, Duck-Sool;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.27 no.1
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    • pp.93-97
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    • 2010
  • Silicone dioxide absorbed polyoxyethylene alkylether sulfate (EU-S75D) surfactant was prepared. The core-shell composite of inorganic/organic were polymerized by using styrene(St) as a shell monomer and potassium persulfate(KPS) as an initiator. We studied the effect of surfactants on the core-shell structure of silicone dioxide/styrene in the presence of an anionic surfactant lauryl sulfate(SLS). The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer(TGA) and morphology of latex by scanning electron microscope(SEM).

Tensile Properties of Hybrid Fiber-Reinforced Reactive Powder Concrete After Exposure to Elevated Temperatures

  • Li, Haiyan;Liu, Gang
    • International Journal of Concrete Structures and Materials
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    • v.10 no.1
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    • pp.29-37
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    • 2016
  • The paper presents a research project on the tensile properties of RPC mixed with both steel and polypropylene fibers after exposure to $20-900^{\circ}C$. The direct and the indirect tensile strength (in bending) were measured through tensile experiment on dog-bone specimens and bending experiment on $40{\times}40{\times}160mm$ prisms. RPC microstructure was analyzed using scanning electron microscope. The results indicate that, steel fibers can significantly improve the tensile performance of hybrid fiber-reinforced RPC, whereas polypropylene fibers have no obvious effect on the tensile performance. With increasing temperature, the flexural and axial tensile strength of hybrid fiber-reinforced RPC substantially decrease linearly, which attributes to the deteriorating microstructure. Based on the experimental results, equations are established to express the decay of the flexural and tensile strength with increasing temperature.

Statistical Factor Analysis of Scanning Electron Microscope (주사전자 현미경의 통계적 인자 해석)

  • Kwon, Sang-Hee;Kim, Byung-Whan
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.335-337
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    • 2009
  • A scanning electron microscope(SEM) is a system that visualizes complex surface features. The resolution of SEM is affected by each of equipment components. In this study, we examined the effects of the four factors including the beam current, magnification, voltage and working distance. A statistical analysis was conducted to investigate the main and interaction effects. For a systematic characterization, a $2^4$ full factorial experiment was conducted. The $R^2$ of constructed statistical model was 88.9%. The main effect revealed that the current and working distance are dominant factors. Of the interactions, those between the current and voltage yielded the highest interaction. 3D plots generated from the model were used to explore various parameter effects.

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Effectiveness for Beauty Improvement of Geranium essential oil on Skin Troubles by Surfactant (계면활성제에 의해 손상된 피부의 Geranium essential oil 미용증진 효과)

  • Choi, Jeung-Suk
    • Journal of the Korean Society of Fashion and Beauty
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    • v.2 no.2 s.2
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    • pp.101-106
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    • 2004
  • Allergic contact dermatitis is a common skin disease resulting from specific immunologic sensitization to topically applied various allergen. The Purpose of this study was to investigate skin morphologic cahnges by light microscopic and scanning electron Microscope, changes of protein band by SDS-PAGE(SDS-polyacrylamide gel electrophoresis) in the skin effectiveness for beruty improvement of Geranium essential oil on skin troubles by surfactant. The results of the study are as follows, 1. From the observed result of FE-Scanning Electron Microscope, groups treated by Geranium essential oil in group treated Geranium essential oil during 1 week in surfactant treated group during 1 week, the group was repaired in irregularity surface of tissue by alleviate-keratinization of Geranium essential oil. 2. As a result of protein analysis the group treated on surfactant was rised protein upper range of 97,0004a11on by hyper-keratinization and group treated during 1 week by surfactant was decreased protein below range of 43,000dalton.

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Characterization of Nano-Grained ZnO Piezoelectric Thin Films Deposited under Various Sputtering Conditions

  • Zhang, Ruirui;Lee, Eunju;Yoon, Giwan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.428-430
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    • 2009
  • C-axis-oriented ZnO thin films were successfully deposited on p-Si (100) in an RF magnetron sputtering system. Deposition conditions such as deposition power, working pressure, and oxygen gas ratio were varied. Crystalline structures of the deposited ZnO films were investigated by a scanning electron microscope (SEM) technique. Results show that the deposition parameters can have a strong impact on the preferred orientations and grain sizes of the deposited ZnO films.

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