• Fire Science and Engineering
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• v.18 no.2
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• pp.12-19
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• 2004

The commercially available IG-541 extinguished agent composed of inert gases was developed for environmental protection. The extinguished agents were considered in terms of physical properties, efficient characteristic, environment, stability, and economical efficiency. The pure and mixture components of physical properties of $N_2$, Ar and $CO_2$ were chosen and compared. The physical properties of density, viscosity and surface tension of inert gases were plotted with the molar ratios of $N_2$/$CO_2$ and Ar/$CO_2$ in terms of a temperature. The extinguished agent in the composition of $N_2$, Ar and $CO_2$, 50/40/10 (mol %) showed relatively high density, low viscosity and moderate surface tension, therefore it was suitable for the alternative extinguished agents.

• 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.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.2
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• pp.21-26
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• 2019

Exposure to a rapidly depressurized environment causes extinction of a burning solid propellant. Experiments have been conducted to determine the rate of depressurization required to extinguish a burning solid propellant. For this purpose, a depressurization combustor was designed and fabricated. The results of this experiment were used to determine the boundary between extinction and non-extinction of AP/HTPB solid propellants under different propellant compositions. Experimental results show that the initial and final pressures have a considerable effect on the critical depressurization rate.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.8
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• pp.718-725
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• 2012

Fuel or oil which is leaked into the aircraft engine bay can make a fire when it is contacted to the engine surface of hot temperature. In order to avoid fire, the fire extinguish system should be designed so that the extinguishing agent is quickly injected and its concentration keeps higher in the fire protection region. FAA requires that the extinguishing agent injected within the fire protection region should be sustained longer than 0.5 second on keeping a higher concentration than 6%. For developing a fire protection system satisfying the FAA regulation, numerical and experimental studies for the injection time and the concentration of the extinguishing agent were conducted. These results showed similar trend for the injection time or concentration, but the data acquisition was delayed due to the response of the sensors in the experiment.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.11a
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• pp.118-123
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• 2000

화재에 대한 소화방법으로서는 점화원의 냉각, 산화제 농도의 감소에 의한 화염의 질식 및 제거소화와 부촉매를 이용한 소화법이 있다. 이중 냉각소화방법은 주로 물을 사용하여 화재를 진압하고 있으나, 유류화재와 전기화재 등에서는 물보다 할론소화약제가 효과적으로 사용되어 왔다. 그러나 할론 등 CFC 계통의 소화약제는 환경오염물질을 내포하며, 지구온난화지수와 오존파괴지수 등이 높아 전세계적으로 그 사용이 중단되고 있다. 이에 대한 대체 기술의 하나로 최근에 관심이 고조되기 시작한 소화기술은 분무 노즐을 이용한 미세물분무(water mist) 소화설비이다.(중략)

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.05a
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• pp.217-220
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• 2002

할론 등 CFC 계통의 소화약제는 환경오염물질을 내포하며, 지구온난화지수와 오존파괴지수 등이 높아 전세계적으로 그 사용이 중단되고 있다 또한, IMO의 SOLAS Chapter II-2에서는 소화설비에 대한 규정으로 할론소화장치의 새로운 설치를 금지하고 있으며, 2002년 7월 1일 이전에 건조된 2,000톤 이상의 현존 여객선은 기관실 전체를 방호하는 고정식 수계국소방출소화설비를 설치하여야 한다고 규정하고 있다. 이에 대체소화기술의 하나로 관심을 끌며 연구되기 시작한 소화방법이 미세물분무노즐을 이용한 소화설비이다.(중략)

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.541-554
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• 2006

Present review is to introduce an omasal sampling technique in rumen proteolysis and to consider some information on the omasal sampling technique with particular emphasis on methodological aspects. Use of the omasal sampling technique provides a new opportunity for accurate estimation of rumen metabolism with overcoming limitations of previous in vivo, in vitro and/or in situ methods. The potential advantages of the present technique compared with post-ruminal sampling techniques include following points; 1) only rumen cannulated animals are required, 2) less endogenous nitrogen (N) is contaminated in omasal digesta and 3) omasal digesta are devoid of exposure to acid peptide hydrolysis occurring in the abomasum. Estimates of soluble non-ammonia N (SNAN) in omasal digesta indicate that the assumptions underlying the in situ method that rapidly degradable N fraction can be degraded at an infinite rate and only insoluble dietary N escapes the rumen may be not valid. Quatitatively higher peptide concentration rather than free amino acid and soluble protein in escapable SNAN suggests that hydrolysis of peptide to amino acid may be the rate-limiting step in rumen proteolysis.

• Fire Science and Engineering
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• v.16 no.3
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• pp.26-31
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• 2002

Bromotrifluoromethane(halon-1301) and bromochlorodifluoromethane(halon-1211) have been widely used as a clean fire extinguishing agents due to their outstanding properties. However, production and use of halon are currently being phased out under an international agreements Montreal Protocol because of global environmental concerns and HFCs have been considered as promising alter-natives for the replacement of halon since their ozone depletion potentials are low. The vapor-liquid equilibrium data are required as important basic information in evaluating the solubility of clean fire extinguishing agents and determining their optimal compositions. In this work, we chose HFCs such as HFC-22 HFC-125, and HFC-l34a for gaseous fire extinguishing agents and nitrogen as a pressurization gas for a proper jet velocity of these agents. Phase equilibria for binary mixtures of nitrogen/HFC-22, nitrogen/HFC-125, and nitrogen/HFC-l34a were measured in the temperature range from 283.15K to 303.15K. For equilibrium measurement, we used a circulation type apparatus in which both vapor and liquid phases were continuously recirculated. The experimental data were relatively well correlated with the Peng-Robinson equation of state with Wong-Sandier mixing rules.

• 방재와보험
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• s.28
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• pp.11-13
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• 1986

• Korean Journal of Poultry Science
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• v.29 no.1
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• pp.19-23
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• 2002

This studs was conducted to investigate the effects of dietary carbohydrase (multi-enzyme: $\alpha$-galactosidase and mannanase) on egg quality and nutrient digestibility in laying hens. One hundred forty four, 47-wk-old, ISA Brown commercial layers were used in a 28-d feeding trial after a 7-d adjustment period. Dietary treatments were 1) CON(basal diet), 2) ME 0.1 (basal diet +0.1% multi -enzyme), 3) ME 0.2 (basal diet + 0.2% multi-enzyme). Fer overall Period, hen-day egg Production, egg weight, egg shell breaking strength and egg shell thickness were not influenced by the multi-enzyme. As the adding levels of multi-enzyme increased in the diet, egg Yolk color and egg Yolk index tended to increase with significant differences. Digestibility of DM was not affected by multi-enzyme. However, digestibility of N increased significantly as the concentration of multi-enzyme in the diet was increased. In conclusion, supplemental carbohydrase in laying hen diets nay have some roles in improving the egg Yolk color and N digestibility.