• 농업과학연구
• /
• 제10권2호
• /
• pp.345-353
• /
• 1983

수용액에 존재하는 중금속이온중의 Hg(II)을 정량적으로 분리 회수하기 위하여 DBHQ(5. 7-dibromo-8-hydroxyquinoline)을 Open-pore polyurethane foam (OPP foam)에 침윤시켜 수지의 응용성을 연구하였다. Hg(II)의 흡착은 DBHQ와 1:2 몰비의 착물형성이 이루어지며 Hg(II)의 흡착과 분리는 Batch법으로 실험하여 최적조건을 결정하였다. 가장 양호한 흡착은 DBHQ의 등전점인 pH5.0 부근에서 그리고 분리하는데는 4M-HCl, 50% 아세톤 용매를 사용하였을 경우가 비교적 정량적인 흡착과 분리가 이루어지는 조건이었으며 이와같은 결과를 기초로 DBHQ-OPP foam에 대한 Hg(II)의 흡착 및 분리에 대한 반응메카니즘을 제안했다.

• 설비공학논문집
• /
• 제8권4호
• /
• pp.497-509
• /
• 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.

• Advances in concrete construction
• /
• 제11권2호
• /
• pp.151-161
• /
• 2021

The major shortcoming of concrete in most of the applications is its high self-weight and thermal conductivity. The emerging trend to overcome these shortcomings is the use of foam-concrete, which is a lightweight concrete consisting of cement, filler, water and a foaming agent. This study aims at the development of a cost-effective high-volume fly-ash foam-concrete insulation wall cladding for existing buildings using natural fiber like rice straw in different proportions. The paper reports the results of systematic studies on various mechanical, acoustic, thermal and durability properties of foam-concrete with and without replacement of cement by fly-ash. Fly-ash replaces 60 percent by weight of cement in foam-concrete. The water-solid ratio of 0.3, the filler ratio of 1:1 by weight, and the density of 1100 kg/㎥ (approx.) are fixed for all the mixes. Rice straw at 1%, 3% and 5% by weight of cement was added to improve the thermal and acoustic efficiency. From the investigations, it was inferred that the strength properties were increased with fly-ash replacement up to 1% rice straw addition. In furtherance, addition of rice straw and fly-ash resulted in improved acoustic and thermal properties.

• 자원리싸이클링
• /
• 제29권1호
• /
• pp.43-52
• /
• 2020

본 연구는 산업부산물을 다량 활용하여 지반 함몰 발생시 긴급 복구를 위한 저강도·고유동 경량기포 콘크리트의 최적배합을 설정하고, 이를 현장에 적용하여 가능성을 평가하기 위한 연구이다. 실험의 변수로는 배합수 대비 기포제의 혼입률과 페이스트 용적대비 기포의 혼입률이며, 실험을 통하여 선정된 최적배합으로 현장적용을 통한 기초특성을 평가하였다. 실험결과 배합수 대비 최적의 기포제 혼입률은 10%가 가장 효율적이라 판단되었으며, 페이스트 대비 선발포된 기포의 혼입률은 170%에서 목표를 만족하였다. 그러나, 현장적용 시안정적인 품질확보를 위하여 기포 혼입률은 140%로 현장의 배합에 적용하였다. 친환경 결합재를 이용한 저강도·고유동 경량기포 콘크리트의 현장적용 결과 목표성능을 모두 만족하여 지반복구용 배합 및 공법으로서의 가능성을 확인하였다. 그러나 기포 및 페이스트간의 분리로 인한 상하부의 품질편차가 발생함에 따라 이의 개선을 위한 후속연구가 요구된다.

• 한국안전학회지
• /
• 제30권4호
• /
• pp.79-85
• /
• 2015

Onboard fire extinguishing system is important to protect cargo and human lives and every oil tanker has foam type fire extinguishing system. Because of environmental problem, agent which contains materials such as Perfluorinated compounds are regulated and the development of the environmental friendly agent is required. The protein foam has less environmental pollution problem and has an excellent fire extinguish performance to oil fire. In the research, bivalency metal salts were added as stabilizer to increase fire resistance and stability of the foam. Ferrous sulfate, Iron chloride and Nickel chloride were used and to adjust to vessel, sea water was applied. As a stabilizer increased, the expansion ratio was raised. However 25% drainage time was decreased over 2.0 wt.% which is knowable that the foam brokes easily. The amount of generated foam was measured to check fluidity of foam and it appeared that when $FeSO_4$ 1.2 wt.% was added, the amount of generated foam reached large and also the 25% drainage time was high. To evaluate the fire extinguishing performance for oil fire, the small scale oil fire test was executed. When $FeSO_4$ 1.2 wt.% was added, fire extinguishing time was in its shortest which informs fluidity of foam and stability are important factors on fire extinguishing efficiency.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
• /
• pp.358-365
• /
• 1996

Lightweight foamed concrete is a concrete which is lighter than normal concrete by mixing prefoamed foam in cement slurry. The objective of this study are to develop prefoamed optimal lightweight foamed concrete using polymer foam agent and to obtain its mechanical characteristics experimentally. This paper presents extensive test data on young's modulus, poisson's ratio, stress-strain curve, the characteristics of strength of the foamed concrete and also presents the mechanical characteristics of the foamed concrete according to foam sizes.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2018년도 추계 학술논문 발표대회
• /
• pp.112-113
• /
• 2018

The present feasible tests are to develop the lightweight concrete using bottom ash aggregates and performed air foam for applying to sustainable high-insulation panel. The main variables investigated are water-to-binder, foam volume ratio, and curing conditions. Test results showed that the lightweight concrete possessed the compressive strength of 5~9 MPa at the air dry density of 951~1,139 kg/m3.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2016년도 추계 학술논문 발표대회
• /
• pp.22-23
• /
• 2016

This study analyzes the properties of foam according to the concentration of vegetable foaming agent that is used in traditional and mixed foaming agent of developing stage, and confirms how the foams influence foamed concrete by searching for properties of foamed concrete according to replacing ratio of vegetable foaming agent and mixed foaming agent. This is for the purpose of providing basic data for the use of foamed concrete through improvement on the problem such as unstability, falling in fluidity and the strength of existed foaming agent.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
• /
• pp.52-53
• /
• 2018

In this study, viscosity analysis of the lightweight foamed mortar was conducted to evaluate the foam stability. According to a series of experiment, void volume related with density of the mixture and viscosity of the mixture were infleunced by water-to-binder ratio and addition of viscosity modifying admixture (VMA). Especially, the stability of the foam inside the mortar was confirmed with adding VMA.

• 한국화재소방학회논문지
• /
• 제10권3호
• /
• pp.29-40
• /
• 1996

포 소화약제는 물보다 비중이 가벼운 액체 가연물 또는 입체면이 많은 건물에서 포 수용액을 팽창 발포시켜 대상물을 덮어 씌우거나 봉쇄해서 질식소화 시킬 수 있다. 포 소화약제로 소화성능이 탁월한 수성막포(AFFF) 소화약제를 노즐에 의해 공기와의 혼합으로 포를 형성하는 기존의 방법과 다른 방법으로 본 연구에서 는 Halon 1301 및 Halon 대체 소화약제를 기포제로 사용하여 소화성능과 팽창비를 향상시킨 소화약제를 개발하게 되었다. 개발한 Halon 1301과 Halon대체 소화약제를 기포제로 사용한 수성막포 소화약제는 적은 양의 수성막포 수용액으로 많은 양의 포를 형성하므로 휴대용 포 소화기 또는 포 소화설비 등에 유용하게 사용할 수 있다.