• Journal of Magnetics
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• 제22권1호
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• pp.49-54
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• 2017

The significant reduction of the image quality caused by the magnetic field of samples is a major problem affecting the application of SEM (scanning electron microscopy) in the analysis of electronic devices. The main reason for this is that the electron trajectory is deflected by the Lorentz force. The usual solution to this problem is degaussing the sample at high temperatures. However, due to the poor heat resistance of some electronic components, it is imperative to find a method that can reduce the impact of magnetic field on the image quality and is straightforward and easy to operate without destroying the sample. In this paper, the influence of different magnetic field directions on the imaging quality was discussed by combining the experiment and software simulation. The principle of the method was studied, and the best observation direction was obtained.

• 펄프종이기술
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• 제44권4호
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• pp.16-24
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• 2012

To characterize the coating structure, diverse methods such as mercury intrusion, nitrogen adsorption and oil absorption methods have been developed and widely employed. These indirect techniques, however, have some limitation to explain the actual coating structure. Recently microscopic observation methods have been tried for analyzing structural characteristics of coating layers. Preparation of the undamaged cross section of a coating layer is essential for obtaining high quality image for analysis. In this study, distortion-free cross-section of the coating layer was prepared using a grinding and polishing technique. The coated paper was embedded in epoxy resin and cured. After curing the resin block it was ground with abrasive papers and then polished with diamond particle suspension and nylon cloth. Polished coating layer was sufficient enough to obtain undamaged cross sectional images with scanning electron microscope under backscattered electron image mode. In addition, the SEM images allowed distinction of the coating layer components. Also S/B latex film formed between pigment particles was visualized by osmium tetroxide staining. Pore size distribution and pore orientation were evaluated by image analysis from SEM cross-sectional images.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 춘계학술발표회 논문집
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• pp.151-159
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• 2003

This study presents method for self-calibration of the SEM(Scanning Electron Microscope) stereo image using the standard microprobe with same grid pattern and using parallel and central perspective projection equation. Result showed that parallel projection method is more suitable for standard microprobe. The maximum error of 3D coordinates acquired by this method did not exceed 5 $\mu\textrm{m}$, and DSM(Digital Surface Model) for three dimensional measurement of the rock sample was generated by the digital photogrammetry. This result can be used for quantification of micro scale change of shape and analysis of the micro morphology of rock due to weathering.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집
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• pp.1-2
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• 2008

Thick films of Carbon fiber were prepared by a heating element of plan shape made in Darin co.. We have investigated surface morphology of the specimen depending on second heat-treatment temperatures. X-ray diffraction patterns of Carbon fiber thick films show that the specimen heat treated below $600^{\circ}C$ was an amorphous phase and the one heat treated above $1100^{\circ}C$ forms a poly-crystallization. Scanning electron microscope(SEM) image of Carbon fiber thick films of the specimen heat treated in between 900 and $1100^{\circ}C$ shows a grain growth. At $1100^{\circ}C$, the specimen stops grain-growing and becomes a poly-crystallization.

• Geomechanics and Engineering
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• 제17권6호
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• pp.565-572
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• 2019

Spatial variability is an inherent characteristic of soil, and auto-correlation length (ACL) is a very important parameter in the reliability or probabilistic analyses of geotechnical engineering that consider the spatial variability of soils. Current methods for estimating the ACL need a large amount of laboratory or in-situ experiments, which is a great obstacle to the application of random field theory to geotechnical reliability analysis and design. To estimate the ACL reasonably and efficiently, we propose a micro-structure based numerical simulation method. The quartet structure generation set algorithm is used to generate stochastic numerical micro-structure of soils, and scanning electron microscope test of soil samples combined with digital image processing technique is adopted to obtain parameters needed in the QSGS algorithm. Then, 2-point correlation function is adopted to calculate the ACL based on the generated numerical micro-structure of soils. Results of a case study shows that the ACL can be estimated efficiently using the proposed method. Sensitivity analysis demonstrates that the ACL will become stable with the increase of mesh density and model size. A model size of $300{\times}300$ with a grid size of $1{\times}1$ is suitable for the calculation of the ACL of clayey soils.

• Applied Microscopy
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• 제40권4호
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• pp.267-270
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• 2010

The skin is the largest organ of the integument system whose surface is closely related with many physiological and pathological conditions. Various methods are used to understand the structural and functional status of human skin. We would like to present usefulness of scanning electron microscopic (SEM) observation of skin replica and its significance of training module for a novice. The silicon replicas from several regions of the body (hand, finger, forearm, lip, and face) were casted by applying Exafine$^{(R)}$ mixture. The positive replicas were prepared by applying EPON 812 mixture on negative silicon replicas. Some of the negative silicon replicas were cut with a razor blade and surface profiles were observed. The negative and positive replicas were coated with platinum and were observed under the scanning electron microscope. We could investigate the detailed structures of the human skin surface without any physical damage to the subject. The positive replicas depicted real surface structure of the human skin vividly. The cross sectional view of the negative silicon replicas provided surface profile clearly. The scanning electron microscopic observation of the human skin replicas would be useful to study skin surface structures and to evaluate medical and esthetical applications.

• 청정기술
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• 제10권4호
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• pp.203-213
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• 2004

천연가스의 열분해법은 천연가스 (CH4)를 고온에서 분해 시켜 수소와 탄소로 전환시키는 기술이다. 천연가스 열분해법의 가장 큰 장점은 이산화탄소의 발생 없이 수소와 탄소를 만드는 것이다. 본 연구에서는 이와같이 천연가스 고온 열분해법을 이용하여 메탄으로부터 수소와 탄소의 생성을 연구하였다. 실험을 통하여 메탄의 고온 열분해시 pyrocarbon이 반응관 내벽에 생성되며 그 위에 탄소가 퇴적되는 plugging 현상이 발생한다는 것을 알 수 있었다. 이 문제를 해결하기 위하여 본 연구에서는 이중관 반응기법, 반응 중간에 주기적으로 $O_2$나 $CO_2$로 퇴적된 탄소를 산화시키는 방법 등을 시도하였으며, 그 결과 어느 정도의 탄소 퇴적 현상을 해결할 수 있었다. 또한 SEM (Scanning Electron Microscope) image를 사용하여 탄소 입자의 크기를 측정하였으며 그 크기는 약 200 nm정도였다.

• 대한디지털의료영상학회논문지
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• 제12권2호
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• pp.145-150
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• 2010

Thick films of carbon fiber were prepared by a heating element of plan shape made in Darin co., We have investigated surface morphology of the specimen depending on heat-treatment temperatures. Scanning electron microscope(SEM) image of carbon fiber thick films of the specimen heat treated shows a grain growth at $1200^{\circ}C$ and becomes a poly-crystallization at $1350^{\circ}C$. The variation of resistivity at the thermally annealed specimen above $600^{\circ}C$ depends on type of the substrates. It may be due to a variation of film thickness and a difference of interfacial phenomena. A heating element of features was affected significantly by skin blood and quantity of heat of the body physiological function. After radiation of farinfrared for plate heating element, the function of biometric physiological is considered of skin blood flow and calorie which greatly affects on individuals. Electromagnetic wave was not influence on the body.

• 한국산학기술학회논문지
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• 제18권2호
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• pp.95-101
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• 2017

본 논문에서는 복합재료로 만들기 위한 전처리 단계에서 수행한 사이징 제거 상태를 영상처리 알고리즘을 적용하여 수치적으로 나타내었고, 전자파 차폐 성능을 높이기 위해서 건식 공정 방식으로 니켈도금 탄소섬유를 제작하였다. 탄소섬유 제조에서 폴리머 종류로 감싸져 나온 사이징은 건식 코팅을 위해서는 제거해야 한다. 사이징이 제거된 상태를 주사 전자현미경(scanning electron microscope, SEM)으로 촬영한 이미지에서 탄소 섬유의 규칙적인 패턴, 즉 상관성을 구함으로써 수치적인 값으로 나타낼 수 있다. 사이징의 제거 방식은 용액, 압축 공기와 용액과 압축공기(하이브리드)로 제거한 SEM 영상에 대하여 제안된 방법을 적용한 결과 하이브리드 방식이 우수함을 확인 할 수 있었다. 그리고 사이징이 제거된 스프레딩 탄소 섬유 롤을 롤투롤 스퍼터 방식으로 니켈도금 탄소 섬유를 제작할 수 있었다. 제작된 30um, 40um과 100um 니켈코팅 탄소섬유에 대해서 전자파 차폐 성능을 측정하였다. 한국산업기술시험원에서 100um 니켈코팅 탄소섬유의 전자파 차폐 성능을 평가한 결과 최저 66.7(dB)에서 최고 73.2(dB)의 전자파 차폐 성능을 보였다. 이것은 구리의 전자파 차폐율과 유사하여 EV/HEV자동차의 케이블로 사용될 수 있다.

• 한국염색가공학회지
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• 제26권4호
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• pp.305-310
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• 2014

In this study, we presented a newly synthesized pyrene-naphthalene diimide(NDI)-pyrene triad. The optical and structural properties were examined using various characterization techniques. A donor-acceptor-donor triad molecule exhibited a strong charge transfer, though there existed neither intramolecular nor intermolecular hydrogen bonding sites, due to the formation of preferential complementary complex between pyrene and NDI. Powder XRD measurement revealed a sharp and distinctive X-ray patterns, indicating the presence of microcrystalline-like structure. POM images showed anisotropic fingerprint texture similar to that of cholesteric phase, and SEM images showed numerous columnar structures with length of 1 to $10{\mu}m$. Above observation clearly demonstrated that ${\pi}$-complementary NDI-pyrene interactions in the traid was strong enough to form columnar aggregates in the long range.