• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.99-108
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• 2018

An oil-tolerant and salt-resistant aqueous foam system was screened out as a possible lubricant to enable cold heavy oil transportation. The microstructures and viscoelasticity and effects of heavy oil, salt and temperature on the foam stability were investigated and new rheological and drainage models were established. The results indicate the foam with multilayered shells belongs to a special microcellular foam. The viscoelasticity could be neglected due to its low relaxation time. The drainage process can be divided into three stages. The foam with quality of 67.9% maintains great stability at high oil and salt concentrations and appropriate elevated temperature.

• Fire Science and Engineering
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• v.23 no.2
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• pp.78-84
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• 2009

We carried out fire extinguishing experiments with three kinds of water mist nozzle system. Fire extinguishing experiment according to installed nozzle height and fuel pan location was done. And fire extinguishing performance was compared with plain water and foam agent mixed solution. Water mist nozzle height was varied with 4m, 3.5m and 3m and position of fuel fan was varied 0.5m and 1m from the center of water mist nozzle. Foam agent that used in this experiment is 3% type of AFFF (Aqueous Film Forming Foam) solution. Experimental result showed the door opening effect was little. Fire extinguishing performance of foam agent mixture water mist was better than the plain water mist only.

• Journal of the Korean Society of Safety
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• v.6 no.1
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• pp.26-30
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• 1991

Flammability, and released toxic halogen gases during combustion about two kinds of flame-retardant flexible foam(F.R. flexible PV foam) were investigated. One of the above was F.R. flexible PU foam with the containment of halogen and the other was manufactured with pure flexible PU foam in aqueous solution of alumina trihydrate(ATH) and dried 4 hours at 10$0^{\circ}C$. Flammability by L.O.I and UL94 HF-1 of the two materials were similarly shown. And combustion gases were analyzed with GC-Mass. HCI, CI$_2$ and HF were detected at both halogen being contained F.R. flexible PU foam and ATH dolng one The reason, to find halogen gases from burning ATH-containing F, R. flexible PU foam which wasn't used for any halogenated F.R., could be considered as by using trichlorofluoromethane with blowing agent to make PU foam. The relative quanity of relesed halogen gases of F.R. flexible PU foam with the containment of halogen had been indicated tree times HCI and CI$_2$, two times HF than ATH containing, respectively.

• Elastomers and Composites
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• v.50 no.2
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• pp.81-86
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• 2015

In this study, natural rubber latex foam was prepared in order to replace commercialized polyurethane foams as a car seat material. Physical properties of the latex foam were investigated and the light stability was improved. The latex foam was mixed in an aqueous solution state, and the degree of foaming and the accelerator ratios were appropriately controlled. Tensile properties, hysteresis and dynamic mechanical properties of the latex foam were measured to compare with those of polyurethane foams. UV light absorbers and radical scavengers were added for improving light stability of the latex foam. Xenon lamp test was conducted to investigate the effects of the reagents on light stability. Our results revealed that the prepared latex foam including a light absorber with an antioxidant showed excellent light stable performances.

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.603-607
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• 2023

Aqueous film forming foam (AFFF) is a critical fire suppression agent used in combating hydrocarbon fires. This type of fire suppressant is highly effective due to its ability to form a protective film, dissipate heat, inhibit combustion, and utilize a blend of chemical substances to extinguish fires. While these properties offer significant advantages in responding to hydrocarbon fires, AFFF is distinct in its deployment as it is dispensed in the form of foam. Therefore, the rheological analysis of AFFF foam using a rheometer plays a crucial role in predicting the spray characteristics of AFFF for combating hydrocarbon fires, and this is closely associated with effective fire suppression. In this study, we conducted rheometer experiments to confirm the non-Newtonian behavior (shear-thinning) of AFFF foam and obtained data on the form's stability. These experimental data are expected to contribute to enhancing the efficiency of fire suppression systems utilizing AFFF.

• Macromolecular Research
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• v.11 no.6
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• pp.488-494
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• 2003

We have fabricated gelatin-immobilized polyurethane foams (PUFG) by dipping polyurethane foam (PUF) in an aqueous solution containing gelatin and by subsequent reaction with glutaraldehyde after freeze-drying. Gelatin aqueous solutions of different concentrations were used as the dipping solutions to control the amount of immobilized gelatin. The average pore size of PUF decreased with an increase in gelatin concentration. It was found from the hepatocyte adhesion experiment that the amount of hepatocytes seeded on PUFG1, prepared by using a 1% aqueous gelatin solution, was higher than that on other PUFGs. The hepatocytes inoculated in PUFG1, were slightly aggregated as the incubation time increased. The cells inoculated in PUFG1 showed higher ammonia removal ability than those monolayer-cultured on a gelatin-immobilized polystyrene dish (PSG) after 1 and 4 days of incubation time. The inoculated cells exhibited higher albumin secretion relative to monolayer-cultured hepatocytes on PSG. Albumin secretion by hepatocytes seeded on PUFG1 was increased by the presence of serum and was further increased by both the presence of serum and cytokines. The results obtained from a 3-(3,4-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that PUFG can provide a better microenvironment for hepatocyte culture along with nutrition and metabolite transfer through the high porosity of PUF.

• Fire Science and Engineering
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• v.26 no.5
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• pp.73-78
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• 2012

This research is to evaluate the fire extinguishing performance of Compressed Air Foam System and this test was conducted using Foam Head System. Compressed Air Foam System adopt the methods of causing the foam by mixing compressed air in foam-aqueous solution, In Overseas, CAFS (Compressed Air Foam System) is generally used because long distance discharge is possible and the water damage can be minimized by reducing the water usage. In this study, Comparative analysis on fire extinguishing effect is done through test to compare the performance between Foam System applied existing air mixture method and Compressed Air Foam System applied AFFF 3 %, foam-extinguishing-agent based on UL162 standard. In Compressed Air Foam System, the volume proportion of air mixture to foam-aqueous solution is 1 to 1 and discharging flow rate is 140 L/min, 160 L/min, 180 L/min, 200 L/min each. As a result of the test, in terms of fire extinguishing performance, fire suppression time for Compressed Air Foam Systems is shorter than for General Air Mixture System in all flow conditions.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.345-353
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• 1983

The polyurethane foam impregnated with 5, 7-dibromo-8-hydroxyquinoline (DBHQ) has been studied to be applied to the quantitative adsorption and recovery of Hg(II) from the aqueous solutions. The adsorption of Hg(II) by DBHQ-OPP foam is due to the chelation between DBHQ-OPP foam and Hg(II) on the foam, forming each colored insoluble chelate with 1:2 mole ratio. The optimum experimental conditions for the adsorption of Hg(II) has been determined. The quantitative recovery of Hg(II) adsorption by the OPP foam and reuse of DBHQ-OPP foam were investigated. Hypothesis on the adsorption and separation mechanism of Hg(II) and DBHQ to the polyurethane foam was proposed.

• 방재와보험
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• s.36
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• pp.31-33
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• 1988

1960년대까지는 저팽창단백포가 유류화재의 진압에 주로 사용되었으니 불소화합물 계면활성제로부터 유출된 합성 AFFF를 개발하면서 해수로도 이의 사용이 가능하고 지역 및 유출화재 예방에서 AFFF 특유의 초기진압효과 및 대형화재를 방지한다는 장점 때문에 널리 사용되고 있으며, 석유화학산업의 저장탱크지역 및 공정지역에서 AFFF와 FPF가 주로 사용되며 부두시설(Oilrig, Marine Tanker, 해상 / 해변터미널)에는 AFFF의 사용이 지배적이다. 현재 사용되고 있는 foam으로는 단백포(Protein: PF), 불화단백포(Fluoroprotein: FPF), 막형성 불화단백포(Film Forming Fluoroprotein Foam: FFFP), 고팽창폼(High Expansion Foam), 수성막 형성폼(Aqueous Film Foaming Foam: AFFF), 알콜폼(Alcohol Resistant Foam: ATD) 등이 있으니 본고에서는 AFFF 중심으로 소개한다.

• Clean Technology
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• v.25 no.3
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• pp.256-262
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• 2019

Hydroxylammonium nitrate (HAN)-based liquid propellants are attracting attention as environmentally friendly propellants because they are not carcinogens and the combustion gases have little toxicity. The catalyst used to decompose the HAN-based liquid propellant in a thruster must have both low temperature activity and high heat resistance. The objective of this study is to prepare an Ru/alumina/metal foam catalyst by supporting alumina slurry on the surface of NiCrAl metal foam using a washing coating method and then to support a ruthenium precursor thereon. The decomposition activity of a HAN aqueous solution of the Ru/alumina/metal foam catalyst was evaluated. The effect of the number of repetitive coatings of alumina slurry on the physical properties of the alumina/metal foam was analyzed. As the number of alumina wash coatings increased, mesopores with a diameter of about 7 nm were well-developed, thereby increasing the surface area and pore volume. It was optimal to repeat the wash coating alumina on the metal foam 12 times to maximize the surface area and pore volume of the alumina/metal foam. Mesopores were also well developed on the surface of the Ru/alumina/metal foam catalyst. It was found that the metal form itself without the active metal and alumina can promote the decomposition reaction of the HAN aqueous solution. In the case of the Ru/alumina/metal foam-550 catalyst, the decomposition onset temperature was significantly lowered compared with that of the thermal decomposition reaction, and ${\Delta}P$ could be greatly increased in the decomposition of the HAN aqueous solution. However, when the catalyst was calcined at $1,200^{\circ}C$, the catalytic activity was lowered inevitably because the surface area and pore volume of the catalyst were drastically reduced and Ru was sintered. Further research is needed to improve the heat resistance of Ru/alumina/metal foam catalysts.