• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.462-462
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• 2010

Glass fiber is widely used in architectural acoustics or building acoustics for sound absorption since it was introduced into China for about 50 years. But recent years, with people pay more attentions to the air cleansing and their health which may be affected by the tiny fiber of the glasswool, a voluntary tendency opposing glass fiber of room using is gradual appeared in China. This paper discusses both the main opinions towards the question whether there are harmful impacts on people health from glassfiber, and the application circumstance of it's applying in china. This paper focuses on another substitute sound absorbing material, melamine foam, to discuss the strong environmental friendly tendency opposing glass fiber of room using in China now.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1372-1377
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• 2008

Since metallic foam will increase the performance of heat exchanger, it have caused many researcher's attention recently. Our research base on the model that metallic foams applied to heat exchanger. In this case, there is three kind of heat transfer mechanisms, heat conduction in fibers, heat transfer by conduction in fluid phase, and internal heat change between solid and fluid phases. In this paper, we first discuss the acceptance of applying thermal equilibrium among the two phases. then to calculate the dimensionless temperature profile along 7 metallic foams. The 7 samples have different characteristics, such as area ratio, effective conductivity, porosity, etc.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.1012-1018
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• 2006

In this study, the insulation performance of thermal insulation materials such as glass wool, polyetylene and flexible lastomeric foam according to water vapor permeance was estimated by using experimental correlation equation. The results showed the conductivity increment of flexible lastomeric foam which has very low-permeability (${\le}0.15[ng/{\cdot}s{\cdot}Pa]\;or\;{\mu}{\ge}1,000$) is about 50% lower than that of glass wool with the lapse of ten years. The conclusion is that moisture inevitably accumulated in permeable Insulations reduces insulation performance and also accelerates surface condensation in the case of cold water system.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.82-84
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• 2006

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.22-29
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• 2015

In this study, we tested to develop and apply structural insulation performance improvement concrete to field, which had compressive strength in 24 MPa and thermal conductivity twice as much as normal concrete. After experiment about slump and air contents, combination product of Plain and calcined diatomite powder showed reduction of slump and air contents and combination product with micro foam cell admixture, we cannot find result of slump and air contents reduction. Unit weight of combination product with insulation performance improvement materials decreased more than that of Plain. In the test of compressive strength, compressive strength of insulation performance improvement concrete decreased more than that of Plain but was content with 24 MPa. thermal conductivity of insulation performance improvement concrete tended to decrease. Freezing and thawing resistance of insulation performance improvement concrete was similar to that of Plain. In carbonation resistance test, combination product with calcined diatomite powder showed the result which was similar to that of Plain. In carbonation resistance test, combination product with micro foam cell admixture showed a increase compared to that of Plain and length variation of combination product generally increased.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.163-166
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• 1997

Aluminium foam material is a highly porous material having complicated cellular structure defined by randomly distributed air pores in metallic matrix. this structure gives the aluminium a set of properties which cannot be achieved by any of conventional treatments. The properties of aluminium foam material significantly depend on its porosity, so that a desired profile of properties can be tailored by changing the foam density. Melting method is the one of foaming processes, which the production has long been considered difficult to realize becaues of such problems as the low foamability of molten metal, the varying size of. cellular structures, solidification shrinkage and so on. These problems, however, have gradually been solved by researchers and some manufacturers are now producing foamed aluminum by their own methods. Most of all, the parameters of solving problem in electric furnace were stirring temperature, stirring velocity, foaming temper:iture, and so on. But it has not considered about those in induction heating, foaming velocity and foaming temperature in semi-solid state yet. Therefore, this paper presents the effects on these parameter to control cell size, quantity and distribution.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.1
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• pp.11-23
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• 2010

A sacrificial member with aluminum foam of excellent energy absorption capacity was proposed for the protection of significant structures. Parametric studies of explicit finite element analyses were performed to investigate the pressure mitigation of close-range air-blasts. The scaled distance of the blast had a range of Z=0.48~0.95 and an empirical blast load function was utilized. The analytical parameters of the aluminum foam were density, thickness and the existence of a cover sheet. Analytical results showed that the transmitted pressure can be controlled to have a similar level of yield values of the foam by using a foam with low density and higher thickness. As the blast load increased, the sacrificial member needed to have higher density and thickness. A cover sheet of the foam clearly showed its effect on the wider distribution of blast pressure. It is necessary to determine the design parameters of sacrificial foams considering different energy dissipation capacities according to the scaled distance.

• Fire Science and Engineering
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• v.10 no.3
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• pp.29-40
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• 1996

The AFFF(Aqueous Film Forming Foam : 3M Company's Light Water) agent are synthetic compounds that foams which are similar to those produced by protein based materials. The foam extinguishing agent was used In the extinguisher was the AFFF agent. We sought, however, to make other foams by using halon 1301 (CF$_3$Br) and halon alternatives, such as HCFC Blend A($CHCIF_2$ 82%, $CF_3$CHCIF 9.5%m $C_{10}$$H_{16}$ 3.75%), HFC-227ea ($CF_3$ $CHFCF_3$) We selected these alternatives instead of air in order to raise the expansion ratio of the AFFF agent. By these means we discovered that it is possible to increase the expansion ratio of the AFFF agent up to 44:1 and up to 24:1 when HFC-227ea was used as a halon alternatives. Therefore our new foam extinguishing agents can be used in a portable extinguish agents can be used in a portable extinguishers.

• Polymer(Korea)
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• v.32 no.5
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• pp.433-439
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• 2008

An atmospheric plasma pre-treatment method was applied to polyurethane foam (density: 0.27) and rubber (butadiene rubber) to improve its contact angle and adhesion using atmospheric plate type reactor. In order to investigate the optimum reaction condition of plasma treatment, type of treatment gas (nitrogen, argon, oxygen, air), rate of gas flow ($30{\sim}100\;mL/min$), and treated time ($0{\sim}30\;s$) were examined in a plate plasma reactor. The result of the surface modification with respect to the treatment procedure was characterized by using SEM and ATR-FTIR. Due to a decrease of the contact angle of various materials, the greatest adhesion strength was achieved at optimum condition such as flow rate of 100 mL/min, reaction time of polyurethane foam 10 s and rubber 3 s for an atmosphere nitrogen gas. Consequently, the atmospheric plasma treatment reduced the wettability of the polyurethane foam and rubber also resulted in the improvement of the adhesion.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.6
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• pp.120-127
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• 2022

Nitrogen oxide(NOx) is a major cause of air pollution, exists in the form of nitrogen monoxide and nitrogen dioxide, and is harmful to the human body. Recently, a number of studies to reduce NOx in the atmosphere have been conducted, and these efforts have been the same in the field of construction materials. It is known that NOx can be efficiently removed by using a photocatalytic reaction. In this study, the NOx removal performance of the foam composite using activated carbon(AC) and titanium dioxide(TiO₂) was investigated. AC was used to enhance the photocatalytic reaction of TiO₂ by increasing the internal specific surface area of the foam composite. In this study, foam composites were prepared using the substitution rate of AC as the main variable. The NOx removal performance of specimen was evaluated according to the test method presented in ISO-22197-1. The specific surface area of the foam composite showed a tendency to increase according to the AC content, but decreased at 15% or more. Also, when the AC substitution rate was 15%, the NOx removal efficiency was the highest.