• 한국안전학회지
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• 제25권4호
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• pp.25-29
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• 2010

Foam concentrate is used for fire-extinguishing purposes, occurring foam, mixed with air. In huge oil-fire or the efficiency of fire-extinguishing with small quantity of water, Foam concentrate is used widely. However, perfluorooc tanoicsulfonate and nonylpenol that are included in Foam concentrate could be exposure in danger while they were discharged. The purpose of the research is the development of environment-friendly high expansion foam that exclude the dangerous substances and improvement of danger of the existing foam concentrate. The developed foam is analyzed as the environment-friendly foam in indexes of the environment-toxicity, the biodegradation appraisal, and the dangerous substances-detecting. In addition, the performances of expansion rate, discharge rate, and fire-extinguishing are suitable in the domestic regulation, so it is useful for fire-extinguishing in real fire situation.

• International Journal of Air-Conditioning and Refrigeration
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• 제15권1호
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• pp.17-24
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• 2007

An experimental investigation was carried out for 4 different types of the aluminum foam heat sinks which were inserted into the annulus. The purpose of this study is to examine the feasibility of a heat sink with high performance forced convective water cooling in the annulus. The local wall temperature distribution, inlet and outlet pressures and temperatures, and heat transfer coefficients were measured for heat flux of 13.6, 18.9, 25.1, 31.4 $kW/m^2$ and Reynolds number ranged from 120 to 9,000. Experimental results show that the departure from the Darcy's law is evident from the pressure loss and the friction factor is much higher while the significant enhancement in Nusselt number is obtained, and average Nusselt number of aluminum foam with high pore density is much higher than that of aluminum foam with low pore density. Correlations for the friction factor is proposed and used for design of thermal applications.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2004년도 추계학술대회 논문집
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• pp.163-165
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• 2004

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.19-20
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• 2018

As energy related problems continue to arise, Korea's thermal insulation market for the zero energy homes is also demanding major changes, but there are no realistic countermeasures. Also, interest in inorganic insulation is growing as damage from multifamily housing fire using flammable insulation materials is increasing. On the other hand, many studies have been conducted on lightweight foam concrete, which implies a sufficient possibility as an insulation material by generating a large amount of air bubbles. However, studies of existion bubble concrete are not quantified by the experimental difficulty of using bubbles when compared. Therefore, in this study, the change in strength due to air pressure using a bubble foam, one of the types of air bubbles for the development of light foam concrete.

• 한국해양공학회지
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• 제20권1호
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• pp.7-15
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• 2006

In this research, the behavior characteristics of cement mixing lightweight soil (CMLS) for recycling of dredged soil in the Nakdong River estuary are experimentally investigated. CMLS is composed of the dredged soil from Nakdong River estuary, cement, and air foam. For this purpose, uniaxial compression tests are carried out for artificially prepared specimens of CMLS, with various initial water contents, cement contents, and mixing ratio of dredged soils. The experimental results of CMLS indicated that the compressive strength is strongly influenced by the cement contents, rather than water contents and air foam. Compressive strength of CMLS increased with an increase in cement content, while it decreased with an increase in water content and air foam content. It was also found that the modulus of deformation E50 was in a range of 44 to 128 times greater than the value of uniaxial compressive strength, cured in 28 days.

• 생물환경조절학회지
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• 제21권3호
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• pp.199-206
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• 2012

본 연구는 새롭게 개발된 무기물인 phenolic foam 배지를 이용한 토마토 파종용 플러그 묘의 생산 가능성을 평가하기 위하여 수행되었다. 토마토 'Madison' 품종을 Grodan 암면, UR 암면, phenolic foam LC, phenolic foam LC-lite 4종류의 펠릿 배지를 플러그 트레이에 파종하였다. 파종 후 7일 동안 발아율을 조사하였다. 묘의 생육은 파종 후 19일째에 측정하였다. Phenolic foam LC와 LC-lite 배지에서 가장 높은 발아율을 보였다. 초장, 하배축, 엽면적, 건물중, 생체중은 암면배지에서 유의적으로 양호한 결과를 나타냈다. 하지만 T/R율과 경경은 phenolic foam LC 배지에서 양호한 결과를 나타냈으며, 총공극과 용기용수량 또한 다른 배지와 비하여 가장 높게 측정되었다. 기상률은 phenolic foam LC 배지에서 가장 낮았다. 전체적으로 phenolic foam 배지인 LC와 LC-lite는 암면배지와 비교하여 유사한 생육을 보였다. 본 연구에서 'Madison' 토마토의 공정 묘 생산을 위한 배지로서 phenolic foam LC와 LC-lite 배지의 이용 가능성이 입증되었다.

• 설비공학논문집
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• 제8권4호
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• pp.497-509
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• 1996

Evacuated powder insulations have long been known to have better thermal performance than existing commercially available insulators, such as fiber glass and CFC-blown foam. To make a composite powder panel, a series of individually evacuated panels was encapsulated in a rigid closed cell foam matrix. The panels were encapsulated in a thin glass sheet barrier to preserve the vacuum. The thermal conductivity of the individual panel was found to be $0.0062W/m^{\circ}K$ by experiment and the polyurethane foam above had a thermal conductivity of $0.024W/m^{\circ}K$. In this study, numerical analysis using finite element method was carried out to investigate insulation performance of rigid foam/evacuated powder composite panel with respect to panel geometries such as panel pitch, panel aspect ratio and panel area ratio. Numerical analysis has indicated that more optimal vacuum panel geometries, much lower overall thermal conductivities can be achieved.

• 한국분말재료학회지
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• 제19권4호
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• pp.278-284
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• 2012

$Al_2O_3$ foam is an important engineering material because of its exceptional high-temperature stability, low thermal conductivity, good wear resistance, and stability in hostile chemical environment. In this work, $Al_2O_3$ foams were designed to control the microstructure, porosity, and cell size by varying different parameters such as the amount of amphiphile, solid loading, and stirring speed. Particle stabilized direct foaming technique was used and the $Al_2O_3$ particles were partially hydrophobized upon the adsorption of valeric acid on particles surface. The foam stability was drastically improved when these particles were irreversibly adsorbed at the air/water interface. However, there is still considerable ambiguity with regard to the effect of process parameters on the microstructure of particle-stabilized foam. In this study, the $Al_2O_3$ foam with open and closed-cell structure, cell size ranging from $20{\mu}m$ to $300{\mu}m$ having single strut wall and porosity from 75% to 93% were successfully fabricated by sintering at $1600^{\circ}C$ for 2 h in air.

• 설비공학논문집
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• 제17권9호
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• pp.855-862
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• 2005

An experimental investigation has been carried out for aluminum foam heat sink inserted into the annulus to examine the feasibility as a heat sink for high performance forced water cooling in the annulus. The local wall temperature distribution, inlet and outlet pressures and temperatures, and heat transfer coefficients were measured for heat flux of 13.6, 18.9, 25.1, 31.4 $kw/m^2$ and Reynolds number ranged from 120 to 2000. Experimental results show that the friction factor is higher than clear annulus without aluminum foam, while the significant augmentation in Nu is obtained. This technique can be used for the compactness of the heat exchanger.

• Computers and Concrete
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• 제33권4호
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• pp.471-479
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• 2024

In urban areas, appropriate backfilling design is necessary to prevent surface subsidence and subsurface cavities after excavation. Expandable foam grout (EFG), a mixture of cement, water, and an admixture, can be used for cavity filling because of its high flowability and volume expansion. EFG volume expansion induces a porous structure that can be quantified by the entrapped air content. This study observed the unit weight variations in the EFG before and after expansion depending on the various admixture-cement and water-cement ratios. Subsequently, the air content before and after expansion and the gravimetric expansion ratios were estimated from the measured unit weights. The air content before expansion linearly increased with an increase in the admixture-cement ratio, resulting in a decrease in the unit weight. The air content after the expansion and the expansion ratio increased nonlinearly, and the curves stabilized at a relatively high admixture-cement ratio. In particular, a reduced water-cement ratio limits the air content generation and expansion ratio, primarily because of the short setting time, even at a high admixture-cement ratio. Based on the results, the relationship between the maximum expansion ratio of EFG and the mixture ingredients (water-cement and admixture-cement ratios) was introduced.