• 제목/요약/키워드: Scanning Electron Microscope

검색결과 2,916건 처리시간 0.194초

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

  • 김재훈;심우성;이영신;차기업;홍석균
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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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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    • 제46권3호
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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.

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

  • 김지원;전종업;부경석
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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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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미니형 주사전자 현미경의 설계 및 제어 (Design and Control of Mini-Scanning Electron Microscope)

  • 박만진;김동환;김영대;장동영;한동철
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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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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이산화규소/아크릴계 유기물의 코어-셀 합성에서 음이온 계면활성제의 영향 (The Effect of Anionic Surfactants in Synthesizing Silicone Dioxide/Acrylate Core-Shell Polymer)

  • 김덕술;박근호
    • 한국응용과학기술학회지
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    • 제26권2호
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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).

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

  • 김덕술;박근호
    • 한국응용과학기술학회지
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    • 제27권1호
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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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    • 제10권1호
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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.

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

  • 권상희;김병환
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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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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계면활성제에 의해 손상된 피부의 Geranium essential oil 미용증진 효과 (Effectiveness for Beauty Improvement of Geranium essential oil on Skin Troubles by Surfactant)

  • 최정숙
    • 한국패션뷰티학회지
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    • 제2권2호
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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
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2009년도 추계학술대회
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    • pp.428-430
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    • 2009
  • 본 논문은 RF 마그네트론 스퍼터링 시스템을 이용하여 p-Si (100) 기판위에 증착된 C축 배향을 가지는 ZnO 박막의 특성을 분석하고 있다. 증착 전력, 공정 압력, 반응가스로 사용된 산소 가스의 비율과 같은 증착 조건들을 변화시켰을 때, ZnO 박막의 결정구조의 변화를 분석한다. 증착된 ZnO 박막의 결정 구조는 주사 전자 현미경(scanning electron microscope, SEM)을 이용하여 조사되었다. 분석 결과 증착 파라미터들은 증착된 ZnO 박막의 결정(grain) 크기와 배향 특성에 강한 영향을 미친다는 사실을 알 수 있다.

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