• Nuclear Engineering and Technology
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• v.38 no.7
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• pp.689-696
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• 2006

For a perforated plate, it is challenging to develop a finite element model due to the necessity of the fine meshing of the plate, especially if it is submerged in fluid. This necessitates the use of a solid plate with equivalent material properties. Unfortunately, the effective elastic constants suggested by the ASME code are deemed not valid for a modal analysis. Therefore, in this study the equivalent material properties of a perforated plate are suggested by performing several finite element analyses with respect to the ligament efficiencies.

• The Korean Journal of Cytopathology
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• v.9 no.1
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• pp.89-94
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• 1998

A case of fine needle aspiration cytology of an osteoclastic giant cell tumor of pancreas, which is an uncommon variant of ductal adenocarcinoma, is described. Aspirated tumor cells were characterized by three populations: (1) bland osteoclast like giant cells with multiple small, round nuclei with distinct nucleoli, and abundant cytoplasm, (2) Individually scattered or loosely clustered medium sized mononuclear tumor cells, having fine chromatin, smooth nuclear membrane, often prominent nucleoli, and high N/C ratio, (3) bland or atypical spindle shaped cells. Osteoid like lacy material was also seen on cell block section. The immunohistochemical studies using paraffin embedded cell block section showed positivities for vimentin and lysozyme in both giant and mononuclear turner cells. However, they were negative for cytokeratin, epithelial membrane antigen, S-100 protein, carcinoembryonic antigen, and p53.

• Proceedings of the Korea Concrete Institute Conference
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• 1990.04a
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• pp.24-28
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• 1990

The purpose of this study is to examine through the experimental study whether the water cooled unprocessed blast furnace slag produced in the country is useful for the fine aggregate of concrete or not. The results of this study show that the quality of the water cooled blast furnace slag is inferior to that of natural river sand and that the concrete made by substituting the water cooled blast furnace slag for fine aggregate have a tendency to decrease to some extent in strength. But if the water cooled blast furnace slag is transformed into more hardened state material, to use it as the fine aggregate of concrete will be possible.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.107-113
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• 1992

This paper is the part of fundamental study considering whether the unprocessed water cooled blastfurnace slag, by-product of iron works, can be useful for some fine aggregate of mortar and concrete. The acquired results in this study show that the qualities of the water cooled blastfurnace slag produced in the state of raw material in the country in not good for using as a fine aggregate of mortar and concrete. To be used as a fine aggregate of concrete the qualities need to be improved in the process of manufacture.

• Geomechanics and Engineering
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• v.6 no.1
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• pp.33-45
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• 2014

Use of geotextile as reinforcement material to improve the weak soil is a popular method these days. Tensile strength of geotextile and the soil-geotextile interaction are the major factors which influence the improvement of the soil. Change in fine content within the sand can change the interface behavior between soil and geotextile. In the present paper, the bearing capacity of unreinforced and geotextile-reinforced sand with different percentages of fines has been studied. A series of model tests have been carried out and the load settlement curves are obtained. The ultimate load carrying capacity of unreinforced and reinforced sand with different percentages of fines is compared. The interface behavior of sand and geotextile with various percentages of fines is also studied. It is observed that sand having around 5% of fine is suitable or permissible for bearing capacity improvement due to the application of geosynthetic reinforcement. The effectiveness of the reinforcement in load carrying capacity improvement decreases due to the addition of excessive amount of fines.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.219-220
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• 2009

The PillPose of this study, powder containing the recycled fine aggregate is appropriate for developing high strength and liquidity, the characteristic of the SCC and it was increased the ratio of mixing the recycled fine aggregates resulted from waste concrete and the natural fine aggregates by 25%, making differential in total 5 levels and applied to SCC. After all, this study was reviewed the physical properties of the fresh concrete, mechanics and durability of the hardened concrete and tried to ensure the possibility of utilizing the recycled fine aggregates as a material for SCC.

• Carbon letters
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• v.11 no.2
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• pp.117-121
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• 2010

The composites of alginate, carbon nanotube, and iron(III) oxide were prepared for the removal of heavy metal in aqueous pollutant. Both alginate and carbon nanotube were used as an adsorbent material and iron oxide was introduced for the easy recovery after removal of heavy metal to eliminate the secondary pollution. The morphology of composites was investigated by FE-SEM showing the carbon nanotubes coated with alginate and the iron oxide dispersed in the alginate matrix. The ferromagnetic properties of composites were shown by including iron(III) oxide additive. The copper ion removal was investigated with ICP AES. The copper ion removal efficiency increased greatly over 60% by using alginate-carbon nanotube composites.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.587-588
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• 2006

Drop-on-Demand (DOD) inkjet printing technology, especially piezo-typed, has been paid attention by industries due to its inherent nature of unbeatable material usage and low cost manufacturing cost. Despite of these key advantages over any other competing manufacturing technologies, the primary disadvantage has been considered as its limited capability to produce fine resolution patterns with a commercially available DOD inkjet print head. Although the main effort has been focused on the production of a DOD inkjet print head with smaller nozzles to overcome this challenging issue, an alternative approach could be taken and it would enable to expand the employment of DOD inkjet printing technology to applications requiring fine patterns further more.

• Carbon letters
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• v.1 no.1
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• pp.12-16
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• 2000

Carbon fiber was reacted with gaseous silicon monoxide which is produced from pack-powder mixture at elevated temperature. As a result of the reaction, two kinds of SiC fiber were obtained. The first one was SiC fibers which were converted from carbon fiber. The fiber is constituted with polycrystal like fine grains or monolithic crystals that have a size from sub-micron to $10\;{\mu}m$. Their size depends on the temperature during the conversion reaction. The second one was ultra-fine SiC fibers that were found on the surface of the converted SiC fibers. The ultra-fine fibers have diameters from 0.08 to $0.2\;{\mu}m$ and their aspect ratio were larger than 100. The chemical composit ion of the ultra-fine fibers was analyzed using an Auger electron spectroscopy. In result, the fibers consist of 51% silicon, 38% carbon and 11% oxygen by weight.

• Journal of the Speleological Society of Korea
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• no.78
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• pp.1-8
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• 2007

The combination of mechano-chemical activation (MCA)and Self-propagating High-temperature Synthesis (SHS) has widened the technical possibilities for both methods. For YBCO systems the investigation showed that a short-term MCA of initial powders before SHS leads to single-phase and ultra-fine products. A new technique for preparation ultra-fine high-temperature superconductors (HTS) of YBCO composition with a grain size d <1m is developed using combination of MCA and SHS. The specific feature of the technique is formation of the $YBa_2Cu_3O_7-$ crystalline lattice directly from an X-ray amorphous state arising as a result of mechanical activation of the original oxide mixture. The technique allows the stage of formation of any intermediate reaction products to be ruled out. X-ray and magnetic studies of ultra-fine high temperature superconductors are carried out. Dimension effects associated with the microstructure peculiarities are revealed. A considerable enhancement of inter-grain critical currents is found to take place in the ultra-fine samples.