• Title/Summary/Keyword: electron microscope

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미역김의 제조와 이화학적 특성에 관한 연구 - 제 1 보 : 미역김의 조직화학적 특성 - (Studies on the Manufacture of Underia pinnatifida Laver and it's Physicochemical Properties - I. Histochemical Properties -)

  • 김길환;김창식
    • 한국식품과학회지
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    • 제14권4호
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    • pp.336-341
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    • 1982
  • 미역김의 제조와 이화학적 특성에 관한 계속 연구로 실시한 미역김의 조직화학적 특성 연구 결과는 다음과 같다. 미역잎은 표층, 피층, 속층으로 구성되어 있는데 미역김의 결합단면을 광학현미경으로 관찰한 결과 피층과 속층이 완전히 파괴되었고 표층세포끼리 결합되어 있었다. 미역김 절편을 $Na_2CO_3$용액 처리로 알진산을 추출한 후 광학현미경으로 검경한 결과 알진산이 추출된 결합부위는 periodic acid schiff reagent반응이 나타나지 않았으며, 한편 미역잎을 $Na_2CO_3$용액으로 미리 처리하여 알진산을 추출한 후에는 정상적인 미역김을 제조할 수 없었고 비정상적인 결합구조이었으므로 알진산이 미역김의 결합물질임을 확인할 수 있었다. 미역김의 결합부위를 전자현미경으로 관찰한 결과 알진산의 결합위치는 미역김의 표층세포막과 세포막사이임이 밝혀졌다. $Na_2CO_3$용액을 처리한 미역잎으로 제조한 비정상적인 미역김의 결합구조는 표층세포껍질로 인지되는 물질만이 서로 엉켜 있었다.

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전자현미경을 이용한 나노셀룰로오스 물질의 형태학적 특성 분석 연구 (Electron Microscopy for the Morphological Characterization of Nanocellulose Materials)

  • 권오경;신수정
    • 펄프종이기술
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    • 제48권1호
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    • pp.5-18
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    • 2016
  • Electron microscopy is an important investigation and analytical method for the morphological characterization of various cellulosic materials, such as micro-crystalline cellulose (MCC), microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC), and cellulose nanocrystals (CNC). However, more accurate morphological analysis requires high-quality micrographs acquired from the proper use of an electron microscope and associated sample preparation methods. Understanding the interaction of electron and matter as well as the importance of sample preparation methods, including drying and staining methods, enables the production of high quality images with adequate information on the nanocellulosic materials. This paper provides a brief overview of the micro and nano structural analysis of cellulose, as investigated using transmission and scanning electron microscopy.

Tannic acid를 이용한 전자현미경 (TEM) 염색효과 (Electron Microscopic Stain Effect by Tannic acid)

  • 윤철종;한정연;김철우;지제근
    • Applied Microscopy
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    • 제24권2호
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    • pp.37-47
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    • 1994
  • Using mouse tissue, we studied electron opacity effect of tannic acid for transmission electron microscopic staining. Tannic acid-glutaraldehyde in 0.1M phosphate buffer was used as a fixative. To compare with this we have tested another method consisting of heavy metal staining after treatment of tannic acid in sodium tetraborate (borax) on glutaraldehyde-fixed sections. We have achieved equally consistent electron opacity in both methods. The elastin, collagen, basal lamina of skin and gap junctions of the epithelial cells gave excellent results, while it was good for glycogen, cilia, and plasma. Also fat cells and lipid droplets gave good preservation when tannic acid was added in the fixative. However, prolonged fixation in tannic acid-added fixative was hazardous for further processing, i.e., sectioning problem and deep electron opacity background.

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주사 투과 전자현미경을 활용한 음극형광 분석법 (Introduction to Cathodoluminescence Spectroscopy Using Scanning Transmission Electron Microscopy)

  • 김성대
    • 한국전기전자재료학회논문지
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    • 제36권4호
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    • pp.326-331
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    • 2023
  • The utilization of scanning transmission electron microscopy (STEM) in conjunction with cathodoluminescence (CL) has emerged as a valuable tool for the investigation of material optical properties. In recent years, this technique has facilitated significant advancements in the fields of plasmonics and quantum emitters by surpassing prior technical restrictions. The review commences by providing an outline of the diverse STEM-CL operating modes and technical aspects of the instrumentation. The review explains the fundamental physics of light production under electron beam irradiation and the physical basis for interpreting STEM-CL experiments for different types of excitations. Additionally, the review compares STEM-CL to other related techniques such as scanning electron microscope CL, photoluminescence, and electron energy-loss spectroscopy.

반도체 장치의 결함해석 (Fault Analysis of Semiconductor Device)

  • 박석준;최성배;오창섭
    • 에너지공학
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    • 제25권1호
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    • pp.192-197
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    • 2016
  • 새로운 재료가 개발되어 점점 반도체 디바이스의 적용으로 인해 반도체 장치 구조의 미세화를 촉진하고 있고 반도체 디바이스의 제조공정에서는 초기불량이나 일정시간 가동 후의 고장이 끊이지 않고 발생하고 있어 그 결함에 대한 해석은 날이 갈수록 중요해지고 있다. 여기서는 반도체 디바이스의 전기적 고장 검출과 디바이스 결함부의 물리해석에 대해 서술한다. 물리해석에는 주사전자현미경이나 투과전자현미경, 집속이온빔가공장치와 같은 전자나 이온을 이용한 장치가 사용되는데 여기서는 그 사용기술과 특성에 대해 서술하고자 한다.

불소 표면 개질 고분자 분리막의 제조와 노블가스 분리특성 (Fabrication of Fluorinated Polymeric Membranes and Their Noble Gas Separation Properties)

  • 김기범;윤국로
    • 공업화학
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    • 제21권4호
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    • pp.475-478
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    • 2010
  • 불소화 반응을 통하여 PDMS을 질소 분위기 하에서 $50{\sim}2000\;{\mu}mol/mol$ 농도의 불소 가스($F_2$)를 사용하여 직접적인 방법으로 복합막 표면개질을 하였고 이를 OM (Optical Microscope), AFM (Atomic Force Microscope), SEM (Scanning electron microscope), FT-IR (Fourier transform infrared spectroscopy)을 측정하여 막 표면을 연구하였고 GC (Gas chromatography)로 혼합 노블가스의 기체 거동을 조사하였다. 다양한 노블 혼합 가스를 사용하여 표면 개질된 PDMS 멤브레인의 선택도가 50% 향상 되었다.

A study on the fine structure of marine diatoms in Korean coastal waters: Genus Thalassiosira 5

  • Park, Joon-Sang;Lee, Jin-Hwan
    • ALGAE
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    • 제25권3호
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    • pp.121-131
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    • 2010
  • Thalassiosira species were collected from October 2007 to January 2009 in an attempt to better understand species diversity of the genus Thalassiosira in Korean coastal waters. A total of 5 Thalassiosira species (T. concaviuscula, T. oceanica, T. partheneia, T. simonsenii and T. nanolineata) were identified here. Most species in this study were of small size, and 5 species were recorded for the first time in Korean coastal waters. Using a scanning electron microscope (SEM), we described distinctive characteristics of fine structure that proved to be important diagnostic characteristics for the identification of each species. The most important diagnostic characteristics for Thalassiosira species identification were the marginal strutted processes, the position of labiate processes, and the areolation. The differential characteristics of the species studied were: T. concaviuscula has a double layered external tubes on the marginal strutted processes; T. oceanica shows marginal ridges that are interlinked between the marginal strutted processes; the valve face of T. partheneia is fairly convex and its labiate process is positioned midway between two strutted processes; T. simonsenii is characterized by two labiate processes and somewhat coarse areolae; and, T. nanolineata has several central strutted processes and linear areolation.

배추흰나비 옆홑눈의 미세구조 (Ultrastructure of Stemmata in Cabbage Butterfly, Pieris rapae L.)

  • 김창식
    • Applied Microscopy
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    • 제25권4호
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    • pp.9-16
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    • 1995
  • Ultrastructure of stemmata(larval eye) of 5th-instar larval in cabbage butterfly, Pieris rapae L, was morphologically investigated with light microscope, scanning electron microscope and transmission electron microscope Six stemmata are on each side of the head. Stemmata V and VI have a Y-shaped sulcus on the surface of their corneal lenses, the others have a columnar shaped process and smooth globular surface. The visual type of stemmata is resembled a single ommatidium of compound eye. The dioptric apparatus are a biconvex shaped cornea and crystalline cone. As a photoreceptor, each stemmata consists of 7 retinular cells arranged into 2 tiers. The first ceil tier of 3 distal retinular cells has formed a V-shaped cup rhabdome and the second cell tier of 4 basal retinular cells has formed a H-shaped fused rhabdome. Each retinular cell filled with pigment granules and contained multivesiclular bodies, coated vesicle and common organelles. The peripheral parts of retinular cells are enveloped by neuroglia cells and retinular cells are surrounded by 3 corneagenous cells. The distal portions of the 3 corneagenous cells contact each other, but the Y-shaped stemmata is separated from each other immediately under the cornea. The 7 axons from each stemma congregate into a bundle and each 7-axon group joins to form a stemmatal nerve, consisting of 42 retinular axons.

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Parametric Study of Methanol Chemical Vapor Deposition Growth for Graphene

  • Cho, Hyunjin;Lee, Changhyup;Oh, In Seoup;Park, Sungchan;Kim, Hwan Chul;Kim, Myung Jong
    • Carbon letters
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    • 제13권4호
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    • pp.205-211
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    • 2012
  • Methanol as a carbon source in chemical vapor deposition (CVD) graphene has an advantage over methane and hydrogen in that we can avoid optimizing an etching reagent condition. Since methanol itself can easily decompose into hydrocarbon and water (an etching reagent) at high temperatures [1], the pressure and the temperature of methanol are the only parameters we have to handle. In this study, synthetic conditions for highly crystalline and large area graphene have been optimized by adjusting pressure and temperature; the effect of each parameter was analyzed systematically by Raman, scanning electron microscope, transmission electron microscope, atomic force microscope, four-point-probe measurement, and UV-Vis. Defect density of graphene, represented by D/G ratio in Raman, decreased with increasing temperature and decreasing pressure; it negatively affected electrical conductivity. From our process and various analyses, methanol CVD growth for graphene has been found to be a safe, cheap, easy, and simple method to produce high quality, large area, and continuous graphene films.

펄스전해가공을 이용한 인바 박판의 가공 형상 및 Overcutting 현상에 관한 연구 (A Study on Processing Shape and Overcutting of Invar Sheet by Pulse Electrochemical Machining)

  • 양부열;김성현;최승건;최웅걸;전광호;이은상
    • 한국생산제조학회지
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    • 제24권3호
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    • pp.314-319
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    • 2015
  • Invar is a compound metal of Fe-Ni system contained 36.5% Ni. The characteristic of invar is that the coefficient of thermal expansion is $1.0{\times}10^{-6}cm/^{\circ}C$. It is approximately 10 times smaller than series of steel. Because of this low thermal expansion characteristic of Invar, it is used to shadow mask of display device such as UHDTV or OLED TV. In this study, pulse current from pulse generator instead of DC current is used to overcome the disadvantages of the conventional electrochemical machining. Pulsed current with different duty factor in PECM affect the precise geometry. Pulse electrochemical machining is conducted to machine the micro hole to the invar sheet with different duty factor. The machined shape and overcut of invar sheet with different duty factor is observed by optical microscope and scanning electron microscope (SEM).