• Elastomers and Composites
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• v.47 no.3
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• pp.246-253
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• 2012

This study was carried out to prepare a type of warm mix asphalt. Through urethane foam and emulsion asphalt preparation techniques a protocol of asphalt foam was made. Then three kinds of flame retardant agents were added in there to alleviate the inherent susceptability of asphalt and foam material to flame and thus flame retardant asphalt foam was made. The internal structure of form asphalt was composed of open cell. The higher the NCO% brought the larger the cell and the stronger also. Asphalt increased the strength of the foam. Among the flame retardant agents employed tritorylphosphate was the most effective.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.268-273
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• 2016

To improve mechanical strength of carbon foams, the carbon black (CB) added carbon foams were fabricated by impregnating different contents of carbon black (CB) and mesophase pitch using polyvinyl alcohol (PVA) solution into polyurethane foam and being followed by heat treatment. The cell wall-thicknesses of carbon foams were controlled by adding amounts of CB, and it was confirmed that the compressive strength of carbon foams was increased as increasing cell wall-thickness. The compressive strength had the highest value of $0.22{\pm}0.05MPa$ with the highest bulk density of $0.44g/cm^3$ when adding 5 wt% CB in carbon foam. However, the thermal conductivity was decreased by adding CB in carbon foam. The results indicated that the thermal conductivities of carbon foams were reduced by increased interlayer spacing ($d_{002}$) with the addition of CB in carbon foams.

• Korean Journal of Construction Engineering and Management
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• v.15 no.3
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• pp.128-135
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• 2014

This paper studied design of slip form system considering the erection of a pylon mock-up. The height of the pylon is 10 m. A rectangular hollow cross-section was considered. The outer and inner dimensions of the pylons were varied with respect to the height. The thickness of 1 sides among the 4 faces were varied. Accordingly the slip form was designed to respond to continuous changes in its dimensions and thickness. Structural analysis was conducted to examine structural safety of the slip form. Virtual construction by BIM proved its practicality. The developed design technologies were successfully applied to the erection of a 10m high pylon executed for field verification test.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.157-164
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• 2021

Recently, a number of studies have been conducted on photocatalysts and adsorbents that can remove harmful substances to improve environmental problems related to fine particles. In this study, a porous foam composites were fabricated using palm-based activated carbon having a large amount of micro-pores and foam concrete with a significantly larger total pore volume compared to general construction materials. To evaluate the adsorption potential of fine particles, the pore structure of the foam composites were analyzed. For the analysis of the pore structure of the foam composite, BET and Harkins-jura theory were applied from the measured nitrogen adsorption isotherm. From the results of the analysis, the specific surface area and micro-pore volume of the foam composite containing activated carbon increased significantly compared to Plain. As thereplacement of activated carbon increased, the specific surface area and micro-pore volume of the foam composite tended to increase. It seems that the foam composite has high adsorption performance for gaseous fine particle precursor such as nitrogen oxides.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.123-127
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• 2012

In order to establish the cause of the deformation of polyurethane foam, compression set was measured according to the aging temperature and time. FT-IR, TGA, DSC and DMA were used for investigating the cause of deformation of aged PUF. The results of FT-IR and TGA reveals that no structure change occurred during deformation of PUF. Resilience of aged PUF was reduced by the increase of reduction ratio in storage modulus over the glass transition temperature of hard segment.

• Journal of the Korean Institute of Gas
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• v.20 no.2
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• pp.30-34
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• 2016

In this study, we synthesized a phenol foam using a resol-type phenol resin as a research for replacing the polyurethane foam used as an insulator for cryogenic temperature, such as LNG or LPG. Foaming agents for synthesizing a phenolic foam was used HCFC-141b or n-pentane, cyclopentane, n-hexane, cyclohexane and a mixture of HFC-365mfc and HFC-227ea respectively. Cyclohexane as a blowing agent exhibited the most superior insulating performance and compressive strength. The heat resistance of polyurethane foam and phenolic foam blown by the cyclohexane, was higher than polyurethane foam.

• The Journal of the Acoustical Society of Korea
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• v.30 no.3
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• pp.158-166
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• 2011

In the present study, copper and nickel foams with an open-celled structure as trabecular-bone-mimicking phantoms were used to investigate the dependencies of group velocity and attenuation coefficient on structural properties such as trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp) in trabecular bone. The group velocity and attenuation coefficient of the copper and nickel foams were measured by a through-transmission method in water, using a pair of broadband, unfocused transducers with a diameter of 12.7 mm and a center frequency of 1.0 MHz. The separation of the Biot's fast and slow waves was consistently observed in the ultrasonic signals transmitted through the copper and nickel foams. The group velocities of the copper and nickel foams showed highly positive correlations with Tb.Th and Tb.Sp. The attenuation coefficient of the copper foam showed a highly negative correlation with Tb.Th and Tb.Sp, whereas that of the nickle foam showed a highly positive correlation with Tb.Th and Tb.Sp. These results advance our understanding of those previously reported by other researchers using trabecular bone samples or phantoms.

• Composites Research
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• v.31 no.4
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• pp.133-138
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• 2018

Polymer foams were used to fill the void in the structure in addition to flame retardant and heat insulation. Polymer foams such as polyurethane, polyisocyanurate, poly(vinyl chloride), polyethylene terephthalate were used to weight lighting materials. In this study, epoxy foam was used to improve mechanical properties of polymer foam. Acid anhydride type hardener reacts with polyol. Using this phenomenon, if blowing agent was added into epoxy resin using acid anhydride type hardener, formation and compressive properties of epoxy foam was studied. Formation of polymer foam was compared with type of blowing agent and concentration of blowing agent via compressive test. As these results, optimized condition of epoxy foam was found and epoxy foam had better compressive property than other polymer foam.

• Transactions of Materials Processing
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• v.1 no.2
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• pp.14-19
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• 1992

분말단조 공정의 해석을 위한 기초연구로서 고용 업셋에 의한 다공질 합금강 프리폼의 치밀화와 소성 변형거동에 관하여 조사하였다. 다공질 프리폼의 소성 유동응력은 용도의 상승에 떠라 감소하였고, 변형속도의 증가에 따라 증가함을 보였다. 또한, 다공질 프리폼의 초기밀도가 더 높을수록 동일한 온도와 하중조건에서 더 높은 치밀화를 보였다. 또한, 밀도변화에 따른 프와송 비를 실험치로 부터 구하였고, 배불림 현상과 체적변화를 고려하여 온도에 따른 진응력-진변형률 관계를 구하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.5939-5944
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• 2014

The foam monitor is equipment for extinguishing fires, particularly for oil tankers or cargo areas of the carrying vessel. This equipment is installed on the cargo tank deck. Generally, the projection distance is important for designing an extinguishment. On the other hand, the form monitors in current industry have been designed by trial and error rather than by numerical analysis method. Therefore, the shape design of the new form of monitor is needed. In this study, numerical analysis was performed to determine the projection distance prediction, and experiment results were used to make a comparison with the analysis results. The proposed method was applied to the modified form of a newly designed monitor in a company.