• Journal of the Korean Graphic Arts Communication Society
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• v.21 no.2
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• pp.67-74
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• 2003

Barrier ribs for PDP(plasma display panel) are commonly utilized to have uniform height and width and to prevent opical crosstalk between adjacent cells. The requirements for such barrier ribs are uniform height and shape, low outgassing rate and low porosity, high aspect ratio, and fine resolution. In this study, we are studied about that to make efficiency of material and high quality barrier ribs for PDP. As a result, could got high barrier ribs of $140{\mu}m$ evenly in 1th phenomenon using watersoluble UV curing resin and know that flatness of upper part is also very good.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.21-24
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• 2005

A computational analysis of hygro-thermal and mechanical behaviour of concrete column at high temperature is presented. The objective of this study is to develop a finite difference model that simulates coupled heat and transport phenomena in reinforced concrete structures exposed to rapid heating conditions such as fires. The theoretical basis for the integrated finite difference method is presented to describe a powerful numerical technique for solving of fluid flow in porous media. The numerical results predict the phenomena of 'moisture clog' and the explosive spalling of concrete under fire. The investigations show that high-strength concrete(HSC) and normal-strength concrete(NSC) exposed to high temperature have different pore pressure buildup dependent on porosity, permeability and moisture contents. HSC has more possibility than NSC on spalling.

• Nuclear Engineering and Technology
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• v.50 no.7
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• pp.1190-1197
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• 2018

Analysis of the GRSW-A model coupled into the FALCON code is extended by simulation of central void formation in fuel pellets due to high-temperature fuel restructuring. The extended calculation is verified against published, well-known experimental data. Good agreement with the data for a central void diameter in pellets of the rod irradiated in an Experimental Breeder Reactor is shown. The new calculation methodology is employed in comparative analysis of modern BWR fuel behavior under assumed high-power operation. The initial fuel porosity is shown to have a major effect on the predicted central void diameter during the operation in question. Discernible effects of a central void on peak fuel temperature and Pellet-Cladding Mechanical Interaction (PCMI) during a simulated power ramp are shown. A mitigating effect on PCMI is largely attributed to the additional free volume in the pellets into which the fuel can creep due to internal compressive stresses during a power ramp.

• Archives of Metallurgy and Materials
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• v.64 no.3
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• pp.917-920
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• 2019

Usually porous metals are known as relatively excellent characteristic such as large surface area, light, lower heat capacity, high toughness and permeability for exhaust gas filter, hydrogen reformer catalyst support. The Ni alloys have high corrosion resistance, heat resistance and chemical stability for high temperature applications. In this study, the Ni-based porous metals have been developed with Hastelloy powder by gas atomization and water atomization in order to find the effects of powder shape on porous metal. Each Hastelloy powder is pressed on disk shape of 2 mm thickness with 12 tons using uniaxial press machine. The specimens are sintered at various temperatures in high vacuum condition. The pore properties were evaluated using Porometer and microstructures were observed with SEM.

• The Korean Journal of Ceramics
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• v.2 no.3
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• pp.142-146
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• 1996

The molten carbonate fuel cell matrices, which are usually made of high surface, fine particle size ${\gamma}-LiAlO_2$ are reinforced with coarse particles of the same material and alumina fibers. An the effects of reinforcing materials on pore characteristics, sintering properties and mechanical properties of the matrices are examined.Among the matrices examined, the highest mechanical reinforcement has been achieved in the one containing 10 wt.% coarse particles and 20 wt.% alumina fibers.

• Journal of the Korean Ceramic Society
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• v.27 no.7
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• pp.891-898
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• 1990

This study deals with the porous sintered body which is obtained by blending solid naphthalene with fine particles of Hwasun flint clay. Apparent porosity is increased, and bulk density, thermal conductivity, strength and thermal expansion are decreased according to the additiion of naphthalene. Pore shape of sintered body showed elliptical form and median size and capilary percentage are increased by adding more naphthalene.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.311-313
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• 2004

WC-12-17%Co powders with nano- and micro-structures were deposited by cold spray process using nitrogen and helium gases. The results show that there is no detrimental phase transformation and/or decarburization of WC by cold spray deposition as expected. It is also observed that nano-sized WC in the feedstock powder is maintained in the cold spray deposition. It is demonstrated that it is possible to fabricate the nano-structured WC-Co coating with low porosity and very high hardness (-2050 HV) by cold spray deposition with reasonable powder preheating.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.225-226
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• 2016

Bottom ash generated in thermoelectric power plants could be used as substitutional fine aggregate such as pearlite of fireproof mortar due to its lightweight and porosity. Development of substitutional materials is necessary because pearlite has several problems such as production of carbon dioxide during manufacturing process and high price. This study is to confirm the possibility of air cooling process bottom ash for fireproof mortar as substitutional material of pearlite through basic experiment.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.231-232
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• 2006

Aluminum Alloys with a content of 22 wt.-% $Mg_2Si$ were spray formed. This alloy features by a low density and is therefore a superior material for leightweight applications. The main problem in spray forming of this type of alloy was the occurance of high porosities. First process optimizations have been performed to decrease porosity under a certain level, so that it can be closed by an extrusion process

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.657-658
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• 2005

Flame retard of polymers was studied for prevention from burning by various additives stimulated the char formation during heating and thermal degradation of polymer materials. Forming char have high porosity, low thermal conductivity and act as thermal shield for heat transmission from the flame to the polymer and. oxygen towards the polymer. The results showed that various additives may regulate the processes of intumecsence. The efficient fire protective intumescent char was result of processes of melting, gas evolution, cross-linking, carbonization etc.