• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.461-464
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• 2004

The reduction effect of floor impact noise depends on the various factors such as stiffness and thickness of the concrete slab, finishing If ceiling materials and the composition method. Among the rest it is well known that floating floor system is more effective. Standard floating floor(SFF) type-2 consisted of 50mm lightweight aerated concrete(LAC) and 20mm damping material has been widely used. But LAC construction problem on dry damping material occurred and the reduction effect of floor impact noise has bare minimum qualifications. Thus the aim of this study is to develop 40mm composite damping material(Soundzero Plus) for SFF type-5 which substitute LAC and damping material. 'Soundzero Plus' is satisfied with quality requirement for damping material for SFF. The heat transition rate, $0.45W/m^2{\cdot}K$ is more effective 55% about than the regulation. The test results of floor impact noise by using 'Soundzero Plus' are showed good improvement about 12dB (tested by tapping machine) and 4dB (tested by bang machine) between before and after.

• Conservation Science in Museum
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• v.12
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• pp.19-24
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• 2011

This study presents an investigation into the conservation process of an iron dagger and scabbard, which are a lacquered scabbard and a dagger inserted in it, excavated in the Daho-ri relic of Changwon by Gimhae National Museum. The bronze dagger whose condition was poor due to corrosion was coated with Incralac, an intensifier, to reveal the surface patterns through a microscope. The lacquered scabbard was removed of foreign substances on the surface and coated with HPC 2%(in water) to protect the film. Applied onto the surface from which foreign substances were removed was Caparol Binder 5%(in water) two to three times to form a protective film and then faced with Korean paper. Once it was fixed in a polyurethane foam in a stable manner, it was turned over to receive the same process on the back. Three layers of Korean paper were attached to the back of the scabbard to support the thin artifact. HPC 2%(in water), which was applied to the scabbard, was also applied to the iron dagger inside for cementing effect. After all the processes were completed, the artifact was put in a transparent acrylic box for future display.

• Fire Science and Engineering
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• v.15 no.3
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• pp.7-13
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• 2001

In this paper, we had analyzed comsbustion gases according to pyrolysis $600^{\circ}c$, $800^{\circ}c$ and $1000^{\circ}c$ for polymeric material using a GASTEC colorimetric gas detector tube in order to combustion gases toxicity evaluation for flame retardant untreated ply wood, flame retardant treated ply wood, flexible polyvinyl chloride and flexible polyurethane foam of polymeric material. As a result, comsbustion gases producted from small specimens of polymeric material had reached fatal to man at a 30 minute exposure time that had possesed toxicity index. Toxicity index at pyrolysis $800^{\circ}c$ of flexible polyvinyl chloride was 31.74. Flexible polyvinyl chloride was the highest toxicity index of flame retardant untreated ply wood, flame retardant treated ply wood, flexible polyvinyl chloride and flexible polyurethane foam. The comsbustion gases producted commonly no concern with pyrolysis temperature had analyzed carbon dioxide($CO_2$) and carbon monoxide(CO). Toxicity index had investigated differently according to pyrolysis temperature even a similar materal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2846-2851
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• 2012

Effects of ground tire rubber(GTR) and unexpanded $Expancel^{(R)}$ powders on the thermal conducting characteristics of rigid polyurethane foams(PUFs) were studied. Sub-micron sized GTR powders and $Expancel^{(R)}$ powders were used as the foam nucleating agents to improve the thermal insulating properties of the rigid PUFs. As the results, while the thermal conductivities of the GTR filled-PUF samples were increased linearly with GTR contents, those of $Expancel^{(R)}$ filled-PUF samples were decreased a little bit. It was considered from the results that GTR powders might predominantly play a role as the extending fillers. On the other hand, $Expancel^{(R)}$ powders could act as the foam nucleating agents based on the polar surface, showing smaller cell sized PUF with improved insulating characteristics.

• Fire Science and Engineering
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• v.17 no.4
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• pp.117-123
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• 2003

In this study; the ignition and heat release rate characteristics of rigid polyurethane foam were investigated in accordance with setchkin ignition tester and cone calorimeter which is using oxygen consumption principle. In the ignition temperature study; flash-ignition temperature was $383^{\circ}C$-$390^{\circ}C$, self-ignition temperature was$ 493^{\circ}C$∼495$^{\circ}C$. The self-ignition temperature of rigid polyurethane foam was about $100^{\circ}C$ higher than the flash-ignition temperature. In the cone calorimeter study, the time to ignition of rigid polyurethane foam was faster as the external heat flux increase. In the same heat flux level, the time to ignition was faster as the density of rigid polyurethane foam decrease. Also the heat release rate was the largest value at the heat flux of /$50 ㎾\m^2$ and had a tendency of increase as the heat flux level and density increase. In the standpoint of time to ignition and heat release rate, the fire performance of rigid polyurethane foam was influenced by the applied heat flux level and density and the flashover propensity classified by Petrella's proposal was high.