• Title/Summary/Keyword: SEM study

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Mineral Properties of Yangsan.Mulkum Clay (양산물금 점토의 광물학적 특성)

  • 정하익;이용수;진규남;진현식
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.75-80
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    • 1999
  • In this study, clay sampled from Yangsan$.$Mulkum site were used to analyze mineral properties. Mineral and chemical properties of clay were investigated through X-ray fluorescence spectrometer(XRF), X-Ray Diffraction(XRD), and Scanning Electron Microscope(SEM) analysis. The result of this test represents that Yangsan$.$Mulkum clay are composed of quartz, albite, anorthite, orthocalse and illite.

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The measurement of p-n junction depth by SEM

  • Hur, Chang-Wu;Lee, Kyu-Chung
    • Journal of information and communication convergence engineering
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    • v.5 no.4
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    • pp.324-327
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    • 2007
  • In this paper, the p-n junction depth with nondestructive method by using scanning electron microscopy (SEM) is determined and conformed. By measuring the critical short circuit current on the p-n junction which induced by electron beam and calculating generation range, the diffusion depth can be obtained. It can be seen that values destructively measured by constant angle lapping and nondestructively by this study almost concur. As this result, it is purposed that diffusion depth of p-n junction can be easily measured by nondestruction. This nondestructive method can be recommended highly to the industrial analysis.

A Study on the Characterization of Individual Particles by SEM-EDX (SEM/EDX법에 의한 개별입자 성상 및 동정에 관한 연구)

  • 염해진;전보경;최금찬
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.396-397
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    • 2003
  • 대기 중에는 가스상 물질뿐만 아니라 액적 또는 고체의 미립자도 존재하고 있다. 이러한 입자상 물질은 다른 크기와 화학적 조성을 가지는 입자들로 혼합되어 있고, 그 성상은 시간에 따라 크게 변동한다. 따라서 대기 중 미세입자에 대한 발생원 추정 및 발생원 정보를 얻기 위해서는 개개의 입자에 대한 물리ㆍ화학적 정보를 얻는 것이 중요하다. 입자상 물질을 이해하기 위해서는 물리적인 특성(size, shape 등)과 화학적인 특성이 중요한 요소이다. 입자상 물질의 형상은 그 발생원에 따라 또는 존재에 따라 매우 다양하고 불규칙적이다. (중략)

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A Study on Mass Fractions of Individual Particles by SEM/EDX in Seoul Subway Stations (SEM/EDX를 이용한 서울시 지하철 역사 내 개별입자의 질량분율에 관한 연구)

  • 한근혁;김동술
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.04a
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    • pp.249-250
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    • 2002
  • 입자상 물질은 호흡에 의해 폐 깊숙이 침착되어 인체에 피해를 줄 수 있다 같은 질량의 거대 및 미세 입자가 있을 경우, 입자의 크기가 작아짐에 따라 비표면적이 급속히 커지기 때문에 입자가 유해 중금속 성분을 함유하고 있을 경우 그 중금속의 농축 정도가 크다. 지하철 역사는 사람들이 가장 많이 생활하는 지하 공간중의 하나이며, 유동인구가 많아 입자상 물질의 발생이 심한 지역으로 외기에 비해 희석, 화산 공간이 크지 않기 때문에 역사 내 유해 환경 오염 물질의 영향과 관리 대책에 대한 연구가 진행되고 있다. (중략)

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Non-destruction and Neutralization Properties of Mortar Mixed with Non-active Hwangto and Stone Dust (비활성 황토와 석분을 혼입한 모르타르의 비파괴 및 중성화 특성)

  • 성찬용;윤준노
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.3
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    • pp.59-64
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    • 2003
  • Hwangto would be an environment-friendly material that can be readily used. The purpose of this study is to obtain the absorption ratio, ultrasonic pulse velocity and neutralization of the mortar with non-active Hwangto and stone dust. The absorption ratio and neutralization depth are increased with increase of non-active Hwangto. But, the ultrasonic pulse velocity is decreased with increase of non-active Hwangto. In results of SEM analysis, the crystals are increased with increase of non-active Hwangto.

Positron Annihilation Study of Vacancy Type Defects in Ti, Si, and BaSrFBr:Eu

  • Lee, Chong Yong
    • Applied Science and Convergence Technology
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    • v.25 no.5
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    • pp.85-87
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    • 2016
  • Coincidence Doppler broadening and positron lifetime methods in positron annihilation spectroscopy has been used to analyze defect structures in metal, semiconductor and polycrystal, respectively. The S parameter and the lifetime (${\tau}$) value show that the defects were strongly related with vacancies. A positive relationship existed between the scanning electron microscope (SEM) images and the positron annihilation spectroscopy (PAS). According to the SEM images and PAS results, measurements of the defects with PAS indicate that it was more affected by the defect than the purity.

A New Sample Preparation Technique for SEM Observation of Polyolefin Microstructure (주사전자현미경상에서의 고분자 미세구조 관찰)

  • Park, Je-Myung
    • Applied Microscopy
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    • v.29 no.4
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    • pp.405-415
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    • 1999
  • In general, transmission electron microscopy (TEM) is usually used in the investigation of polymer microstructure. Microtoming, solution casting, staining and carbon replica method are frequently introduced to the study of the polymer morphology with TEM, however the sample preparation procedure of those techniques is very difficult, and it takes a long time. The purpose of this study is to develop a new sample preparation technique which is suitable for the investigation of the various shapes and species of polyolefin microstructure by scanning electron microscopy (SEM). By modifying the conventional chemical etching method, we developed a new chemical etching technique and sample preparation procedure that are suitable for SEM study of polymer microstructure. In this study the permanganate etching method is introduced and the optimum etching condition are determined by simply adjusting the etchant formulation, concentration and etching time. This technique has shown good reproducibility and it's morphological results agree well with other works on various types of microstructures such as spherulite characterization of isotatic polypropylene $(\alpha/\beta)$, polyethylene and poly-propylene copolymer characterization, and the study of lamellar growth pattern of unsheared or oriented materials. This technique has also been applied to the industrial fields for characterization of the polyolefin film, automobile products and the others.

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Morphology and Chemical Composition Analysis of Human Cremated Ash by SEM/EDS (SEM/EDS를 이용한 화장 분골의 형태와 성분 분석)

  • Hwang, Kyu-Sung;An, Woo-Hwan;Kim, Jeong-Lae
    • The Journal of the Convergence on Culture Technology
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    • v.1 no.2
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    • pp.65-69
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    • 2015
  • Teeth and bones are very resistance to high temperatures and remain recognizable even after prolonged exposures to heat. The effects of heating and burning on teeth have been studied with the aim of discerning a characteristic signature withstanding high temperature, but there have been few studies about a human cremated ash, especially Korea. We are recognizable by elemental composition and can be detected in human cremated ash samples by Scanning electromicroscopy/Energy dispersive X-ray spectrometry analysis(SEM/EDS), cremated, at $800{\sim}900^{\circ}C$ for 1 hour. In this temperature range, different crystals morphologies(spherical, irregular and hexagonal) are observed in SEM. Calcium(Ca) and oxygen(O) increases steadily after cremation in EDS. We suggest that cremated bone have been provided with calcium oxide(CaO) formation at temperature above $900^{\circ}C$. This study offers basic data to assess the structure and elemental compositions of human ash and to determine if these remain identifiable after exposure to extreme temperatures.

ROLE OF SYMPATHETIC NERVE ON THE CONTROL OF MICROCIRCULATION IN THE FELINE DENTAL PULP (고양이 치수에서 교감신경에 의한 미세순환조절에 관한 기능적 연구)

  • Kim, Sung-Kyo
    • Restorative Dentistry and Endodontics
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    • v.21 no.1
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    • pp.375-384
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    • 1996
  • The purpose of this study was to investigate the functional involvement of sympathetic nerve in the control of the microcirculation in the dental pulp with the aim of elucidation of the involvement of neuropeptides and sympathetic nerve in neurogenic inflammation. Experiments were done on the 7 cats anesthetised with sodium pentobarbital, and sympathetic nerve to the' dental pulp was stimulated electrically (10 Hz, 4 V, 1.5 ms, 3.5 mins). Ana-adrenoceptor antagonist phentolamine and a neuropeptide Y antagonist D-myo-inositol-1,2,6-trisphosphate (PP56) were injected close intra-arterially into the dental pulp without changing the systemic blood pressure. The probe of laser Doppler flowmeter was placed on the buccal surface of ipsilateral canine teeth to the stimulation, and pulpal blood flow was measured. Stimulation of the sympathetic nerve decreased pulpal blood flow by $55.24{\pm}7.74\;%$ (mean${\pm}$SEM, n = 13). Stimulation of the sympathetic nerve following the injection of the ${\alpha}$-adrenoceptor antagonist phentolamine ($0.1{\mu}g$/kg) caused decrease of pulpal blood flow by $14.35{\pm}3.43%$ (mean${\pm}$SEM, n=5). Phentolamine attenuated the sympathetic nerve-induced pulpal blood flow decrease by $74.02{\pm}9.32%$ (mean${\pm}$SEM) Stimulation of the sympathetic nerve following the injection of the neuropeptide Y antagonist PP56 (2.3 mg/kg) caused decrease of pulpal blood flow by $30.64{\pm}7.92%$ (mean${\pm}$SEM, n=6). PP56 attenuated the sympathetic nerve-induced pulpal blood flow decrease by $44.37{\pm}11.01%$ (mean${\pm}$SEM). These data provide evidences of the co-contribution of nerepinephrine and neuropeptide Y on the sympathetic nerve-induced vasoconstriction in the feline dental pulp. In addition, they show functional evidences that sympathetic nerve plays an active role in controlling the microcirculation of the dental pulp.

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Archeological Chemical analysis and Characteristic Investigation on Glass Beads Excavated in Sacheon Neukdo Island, Gyeongsangnam-do (경남 사천 늑도 유적 출토 유리구슬의 고고화학적 특성 고찰)

  • Kwon, Yoon-Mi;Kim, Gyu-Ho;Shin, Yong-Min
    • Journal of Conservation Science
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    • v.20
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    • pp.105-117
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    • 2007
  • This study is examined the beads excavated in the Sacheon Neukdo ruins to investigate the features of archaeological chemistry and to compare those of the same type of beads excavated within the Gyeongsang-do area by means of scientific analysis. The samples have been observed the micro-structures by an optical microscope and SEM and confirmed the physical property by density measurement. Chemical property have been analyzed main components such as flux, stabilizers, and colorants by SEM-EDS. Besides, XRD was used to identified the characteristic materials of beads. The white opaque beads, which was initially estimated as sea-shell beads, confirm as amorphous silica material. The glass beads, which are blue type as a result of compositional analysis, it is revealed potash glass group and LCA(Low-CaO, $Al_2O_3$) system. gB ones are revealed only in LCA-A(LCA-CaO<$Al_2O_3$), while purple blue ones in LCA-B(LCA-CaO>$Al_2O_3$).

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