• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.2
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• pp.58-72
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• 2002

The high resolution transmission electron microscope(HRTEM) is one of the most powerful methods fer investigating internal structures of various materials on an atomic scale. In fact, HRTEM images are becoming much more common in scientific papers, and are making valuable contributions to development of industrial products. With rapid improvement of current HRTEMS, their maximum resolution reaches almost 0.1 nm. In this paper we describe the fundamental formulation of the imaging process of HRTEM and their practical application f3r nano materials.

• Applied Microscopy
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• v.37 no.4
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• pp.259-269
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• 2007

In this paper we explored a possibility of observation for effects of higher-order Laue zone(HOLZ) reflections on high resolution transmission electron microscope(HRTEM) images for illumination along an off-zone axis of a crystal. The analysis of the observation could give useful three dimensional crystal structure information. For the image simulation the Howie-Whelan equation was used with modification of including HOLZ reflections. This study clearly indicates that HRTEM images for a very thin crystal tilted by a few degrees from a zone axis show the effects of HOLZ reflections and contain some information of atomic arrangements along the zone axis.

• Ceramist
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• v.10 no.5
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• pp.68-73
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• 2007

• Korean Journal of Crystallography
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• v.11 no.2
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• pp.108-122
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• 2000

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.19-19
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• 2002

• 한국전자현미경학회:학술대회논문집
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• 1998.05a
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• pp.53-55
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• 1998

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.179-186
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• 2021

In this study, we attempted to comparatively analyze the structural characteristics of soot generated from marine engines to review the possibility of recycling crankcase soot by classifying it as exhaust soot and crankcase soot. The annealing procedure was performed in an argon gas atmosphere at 2,000℃ and 2,700℃, and Raman spectroscopy and High-Resolution Transmission Electron Microscopy(HRTEM) were used to analyze the structural properties of the samples. Furthermore, digital image processing techniques were utilized to quantitatively analyze the acquired HRTEM images. The Raman analysis demonstrated a relatively high G/D ratio in the exhaust soot and annealing conditions at 2,700℃. In the HRTEM images, both soot were able to identify similar forms of graphite nanostructures, but there were limitations in that they could not quantitatively derive differences in the degree of graphite depending on the type of soot and annealing temperature. Thus, digital image processing quantitatively analyzed the length and tortuosity of the fringe of the HRTEM image, which is consistent with the Raman analysis. This meant that the exhaust soot had a more graphite structure than the crankcase soot, and that annealing at a higher temperature improved the graphite structure. This study confirmed that both the crankcase soot and exhaust soot can be recycled as a graphite materials.

• Applied Microscopy
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• v.39 no.2
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• pp.175-183
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• 2009

In this paper we present sub-50 pm resolution images of atom columns simulated with the negative of the second derivative of the exit-plane wave function (EPW). The EPW can be retrieved from a focal series reconstruction in the (high resolution) transmission electron microscopy (HRTEM). The simulated images are for Si and InAs in [114] and [116] orientations, which give about sub-50 pm separations of atom columns. The theoretical reason for the validity of this method is given from analysis based on the kinematical diffraction theory, and the limitation for applicability of this method also is discussed.

• Applied Microscopy
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• v.38 no.1
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• pp.63-72
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• 2008

The iterative wave-function reconstruction (IWFR) method developed by Allen et al. (2004) was reviewed with concern for its applicability. The high resolution transmission electron microscopy (HRTEM) studies of the materials such as GaAs, $YBa_2Cu_3O_7$ and $Al_2CuMg$ reported in the literature were utilized in this review. In this process the basis of validity, the limiting conditions and the information limit of this method were discussed. It was particularly noted that the phase contrast image of the exit plane wave evaluated from this method reveals not only $C_s$-corrected atomic resolution within information limit, but also strong tendency of contrast proportional to the magnitude of the atomic number of compositional atoms in a crystal.

• Applied Microscopy
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• v.44 no.4
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• pp.138-143
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• 2014

Transmission electron microscope (TEM) is an excellent tool for studying the structure and properties of nanostructured materials. As the development of $C_s$-corrected TEM, the direct analysis of atomic structures of nanostructured materials can be performed in the high-resolution transmission electron microscopy (HRTEM). Especially, fast Fourier transform (FFT) technique in image processing is very useful way to determine the crystal structure of HRTEM images in reciprocal space. To apply FFT technique in HRTEM analysis in more reasonable and friendly manner, we made a new circular region of interest (C-ROI) FFT script and tested it for several HRTEM analysis. Consequentially, it was proved that the new FFT application shows more quantitative and clearer results than conventional FFT script by removing the streaky artifacts in FFT pattern images. Finally, it is expected that the new FFT script gives great advantages for quantitative interpretation of HRTEM images of many nanostructured materials.