• 한국도로학회논문집
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• 제18권6호
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• pp.41-50
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• 2016

OBJECTIVES : In this study, microstructural components of crumb rubber modified asphalt (CRMA) binder were investigated using environmental scanning electron microscope (ESEM). To clearly understand the elemental composition of the CRMA binder, energy dispersive X-ray spectroscopy (EDX) was employed on the ESEM samples. METHODS : CRMA binders were produced using open blade mixers at $177^{\circ}C$ for 30 min. The binders were artificially aged through a series of accelerated aging processes. Sample preparation was done by making a mold shape on the glass slide. Thereafter, the morphology of the CRMA binder was observed using the ESEM coupled with the EDX. RESULTS : The images captured from the ESEM indicate that the unaged CRMA binder appears to have a single-phase continuous nonuniform structure after the addition of crumb rubber particles, whereas the artificially aged CRMA binder was observed to have two different phases. ESEM coupled with EDX shows detailed internal structure of the modified binders compared to other technologies (i.e., optical microscopy, atomic force microscopy, and conventional scanning electron microscope). CONCLUSIONS : The captured images resemble the internal structures such as the viscous properties of the unaged CRMA binder and the interaction between the rubber particles and the base binder at aged condition. ESEM is a powerful instrument and with the introduction of EDX, it provided more details of the network microstructure of the asphalt binder. ESEM coupled with EDX is recommended for use in future investigation of microstructure of asphalt binders.

• Korean Chemical Engineering Research
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• 제46권1호
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• pp.170-174
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• 2008

리튬염을 포함하는 P(VDF-HFP)계 겔 고분자에 surfactant-assisted templating process로 합성한 메조포러스 ZnS를 충전하여 다양한 ZnS 무게비를 가지는 전해질 필름을 제조하였고 겔 필름의 이온 전도도를 온도에 따라 측정하였다. 그 결과, 대체적으로 ZnS의 함량비가 증가할수록 증가하였다. 특히 20 wt%와 25 wt% ZnS를 포함하는 겔 필름은 상온에서 $10^{-4}Scm^{-1}$의 높은 이온 전도도를 보였다. 하지만 20 wt% 이상의 함량비에서는 더 이상 이온 전도도가 증가하지 않았다. 합성된 메조포러스 ZnS와 겔 전해질 필름의 특성은 XRD(x-ray diffractometer), DSC(differential scanning calorimetry), TGA(thermogravimetric analysis), FT-IR(fourier transform-infrared spectrometer), SEM(scanning electron microscopy), TEM(transmission electron microscopy)을 이용하여 분석하였다. 이온 전도도는 교류 임피던스법에 따라서 승온하면서 측정하였다.

• Applied Microscopy
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• 제15권2호
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• pp.98-110
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• 1985

This study was performed to clarify the morphological structures of the epithelia of the renal papilla, renal pelvis and ureter of the sheep (Ovis aries L.) through the light and scanning electron microscopes, Tissue specimens were taken from the renal papilla (common renal papilla and peripelvic column) and the renal pelvis (pelvis proper and pelvic pouch) of the kidney and the ureter. For the light microscopy, tissue blocks were fixed in 10 % neutral buffered formalin and embedded in paraffin wax, serially sectioned at a thickness of $6{\mu}m$. These sections were stained with hematoxylin-eosin and periodic acid-Schiff reaction. For the scanning electron microscopy, tissue blocks were prefixed in 1% glutaral-dehyde-1.5% paraformaldehyde solution and postfixed in 1% osmium tetroxide solution, dehydrated in graded alcohol, transferred to isoamyl acetate, and then dried by the critical point dryer (Polaron E 3000). These dried tissues were coated with gold and observed with a scanning electron microscope (JSM-35C), The results were as follows: The apex of the common renal papilla was lined with simple columnar epithelium having many microvilli on its luminal surface. Lateral portion of the papilla was lined with stratified epithelium $2{\sim}3$ layers thick, and its superficial cells were microvillar cells having many microvilli. The epithelium lining the peripelvic column was $1{\sim}2$ layers thick. The superficial layer was made of the microvillar cells, but a few microplica cells were appeared in the region near the pelvic pouch. The epithelium of the pelvic pouch was $1{\sim}2$ layered transitional type, and its superficial cells were microplica cells. The epithelia of the pelvis proper and ureter were $4{\sim}6$ layered transitional type, and their superficial cells were typical facet cells existing many round depressions and ridges of cell membranes of the luminal side.

• Applied Microscopy
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• 제43권1호
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• pp.34-39
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• 2013

Glandular and nonglandular trichomes on the leaf surface of Plectranthus tomentosa were investigated by variable pressure field emission scanning electron microscopy (VP-FESEM). The segments of the plant's leaves were directly mounted without any specimen preparation, and examined at ambient temperature using a variable pressure secondary electron (SE) detector under ca. 15 Pa. Foliar trichomes maintained their shapes and structures without severe surface collapse or charging. The adaxial leaf surface was abundantly covered with different types of trichome. Nonglandular trichomes consisted of a basal cell and a long (up to ca. $300{\mu}m$) stalk. Meanwhile, capitate glandular trichomes had a secretory head and a short or long stalk. Peltate glandular trichomes with globose secretory heads were observed in close contact with the leaf epidermis. Spherical projections on the secretory head showed the secretion process of glandular trichomes. In addition to the trichomes, oval stomata were distributed on the abaxial leaf surface. These results suggest that ambient VP-FESEM can be used to classify the dehydration-sensitive foliar trichomes of succulent plants by SE imaging. At the FESEM resolution, this approach facilitates the rapid and detailed morphological analysis of a variety of trichomes in diverse plant taxa with reduced labor and preparation.

• 폴리머
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• 제35권6호
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• pp.553-557
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• 2011

전기방사법을 이용하여 폴리(비닐 알코올)(poly(vinyl alcohol), PVA)/수분산 폴리우레탄(waterborne polyurethane, WBPU)/montmorillonite clay(MMT) 나노복합섬유를 제조하고 특성을 분석하였다. Scanning electron microscopy(SEM), transmission electron microscopy(TEM), X선 회절, thermal gravimetric analyzer(TGA) 의 분석장비들을 이용하여 제조된 나노복합섬유의 형태와 구조적, 열적특성을 확인한 결과, 평균직경이 600~900 nm인 나노복합섬유들이 성공적으로 제조되었으며, MMT가 나노섬유 내에 완전박리되어 기존의 고분자 나노섬유에 비해 열적성질이 향상되었음을 확인할 수 있었다. 본 연구를 통해 제조된 나노복합섬유는 친수성이고 생체친화적인 재료들을 이용하여 제조되었으며, 의료 분야를 비롯하여 의류 및 산업용 코팅제, 필터 등의 분야로 이용이 가능할 것으로 보인다.

• 한국공작기계학회논문집
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• 제17권5호
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• pp.52-57
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• 2008

Most of the electrons emitted from the filament, are captured by the anode. The portion of the electron current that leaves the gun through the hole in the anode is called the beam current. Electron beam probe is called the focused beam on the specimen. Because of the lenes and aperture, the probe current becomes smaller than the beam current. It generate various signals(backscattered electron, secondary electron) in an interaction with the specimen atoms. Backscattered electron provide an useful signal for composition and local specimen surface inclination. Secondary electron is used far the formation of surface imagination. The steady electron beam probe is very important for the imagination formation and the brightness. In this paper, we show the results of developed elements that create electron beam probe and the measured beam probe in various acceleration voltages by Faraday cup. These data are used to analysis and improve the performance of the system in the development.

• 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.

• Applied Microscopy
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• 제46권2호
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• pp.76-82
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• 2016

Aloe vera has been used in the pharmaceutical, food and cosmetic industry for its therapeutic properties. However, there are not many current studies on the microstructure of A. vera compared to studies on the chemical constituents and health efficacy of A. vera. Therefore, we compared the morphology of an A. vera leaf using an optical microscope, a conventional scanning electron microscope (SEM) and a cryo-SEM. Especially, this study focused on observing the gel in the inner leaf of A. vera, which is challenging using standard imaging techniques. We found that cryo-SEM is most suitable method for the observation of highly hydrated biomaterials such as A. vera without removing moisture in samples. In addition, we found the optimal analytical conditions of cryo-SEM. The sublimation conditions of $-100^{\circ}C$ and 10 minutes possibly enable the surface of the inner leaf of A. vera to be observed in their "near life-like" state with retaining moisture. The experiment was repeated with A. arborescens and A. saponaria to confirm the feasibility of the conditions. The results of this study can be applied towards the basic research of aloe and further extend previous knowledge about the surface structures of the various succulent plants.

• Applied Microscopy
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• 제30권2호
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• pp.205-212
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• 2000

Present study was performed to observe the surface ultrastructures of Stictadora furcatum (Trematoda: Heterophyidae). Adult worms were recovered from the cat experimentally infected with metacercariae, and were prepared for scanning electron microscopy. The body was leaf-like and ventrally concave. The oral sucker armed with prominent tegumental spines on the inner surface, and it's lips were obscure. Sensory papillae (type I) in single or grouped forms symmetrically arranged around the oral sucker. The ventrogenital opening retained protruding gonotyl spines and sperms discharged from the genital pore . The body surface was covered with scale-like multipointed tegumental spines. The density and digitated point of spines were gradually decreased toward the posterior end of the body. The digitated points of spines on the anterior portion were 9-12, on the middle were 7-8 and 5-6, and on the posterior were 2-3 and peg-like. Although the tegumental ultrastructure of S. fuscatum was generally similar to those of other heterophyid flukes , the oral sucker with tegumental spines on the inner surface and without obvious lips, and the ventrogenital opening with protruding gonotyl spines were suggested to be the characteristic features.

• Macromolecular Research
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• 제16권7호
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• pp.604-608
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• 2008

Color dye-doped silk fibroin nanoparticles were successfully fabricated using a microemulsion method. An aqueous silk fibroin solution was prepared by dissolving cocoons (Bombyx mori) in a concentrated lithium bromide solution followed by dialysis. A color dye solution was also mixed with the aqueous silk fibroin solution. The surfactants used for the microemulsion were then removed by methanol and ethanol, yielding color dye-doped silk fibroin nanoparticles, approximately 167 nm in diameter. The secondary structure of the nanoparticles showed a $\beta$-sheet conformation, as characterized by Fourier transform infrared spectroscopy. The morphology of the nanoparticles was determined by field emission scanning electron microscopy, transmission electron microscopy and atomic force microscopy, and their size and size distribution were measured by dynamic light scattering. The color dye-doped silk fibroin nanoparticles were examined by confocal laser scanning microscopy.