• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.4
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• pp.632-639
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• 1997

Relative density and microstructure of the pressureless sintered TiC-$TiB_2$ composite has been studied. The maximum sintered density was 95% and the critical amounts of sintering aids were 1 wt% Fe and 3 wt% Ni. It was found that TiC matrix phase inhibited effectively grain growth of the dispersed $TiB_2$ phase. The TEM investigation reveals that the Ni-rich precipitates were solidified from the liquid phase, confirmed by the presence of the waved and/or step phase boundaries. The precipitates also acts as the origin of the dislocation formation in the matrix phases.

• Journal of Energy Engineering
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• v.17 no.4
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• pp.175-181
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• 2008

지난 10여년간 한국 사회는 기술적, 경제적, 정치적으로 많은 성장과 변화, 그리고 발전을 거듭하여 세계 13의 경쟁력을 자랑하고 있다. 하지만, 우리나라의 사회적 성장 수준은 세계 30위에 그치고 있어 노령화 정책, 환경 문제, 양극화문제, 균형 발전 등의 사회적 성장과 삶의 질 향상을 위한 노력이 필요한 상황이다. 지속가능한 안전한 삶에 대한 국민적 관심과 요구가 높아지고 있음에도 불구하고 우리 사회는 일상생활과 밀접한 전기 화재 및 가스 사고에서부터 국가 산업 경쟁력 및 심각한 환경문제까지 야기할 수 있는 발전소 혹은 대형 플랜트 사고에 이르기까지 위험 요소를 안고 있다. 이에 본 연구는 이러한 에너지 관련 시설 및 활동으로부터 발생할 수 있는 사고를 예방하고 조치할 수 있는 안전 기술 개발 현황에 대하여 조사하고 이를 바탕으로 향후 국내 에너지 안전 기술의 개발 방향에 대한 의견을 제안하였다. 또한, 국내 가스 및 설비 안전 기술의 현황을 파악하고 이를 토대로 안전 기술의 유형을 분류하여 향후 관련 기술의 방향성 제시를 위해 중장기 TRM(technical road map)을 제시하여 에너지 안전 기술의 경쟁력 확보를 위한 토대를 마련하였다.

• Fire Science and Engineering
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• v.34 no.4
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• pp.101-106
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• 2020

This study analyzed flame growth characteristics and carbonization patterns when floor materials were burned vertically using a needle flame produced for this study. It was found that PVC flooring was fire retardant and the area under direct flame contracted inward. Vertical combustion causes solidification in the form of a lump at the bottom and also generates soot in a pattern that progresses upwards. This study found that laminated flooring exhibited no fire retarding characteristics and that the laminated layer of its upper surface was destroyed by fire, causing irregular delamination. The carbonization ranges at the left and right sides were determined to be symmetrical. A vertical combustion test of a sample carpet showed that it exhibited no fire-retarding characteristics. It was observed that if heat accumulated in the carpet, the flame formed an ascending air current, and that when flammable materials were present around the flame, they further accelerated the diffusion of the flame. The carbonization pattern at the carpet surface exposed to direct flame revealed that the carpet surface had melted and had flown downwards and that many tiny holes formed on it.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.197-204
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• 2021

This study investigated the smoke risk assessment of woods and plastics for construction materials, focusing on the smoke performance index-V (SPI-V), smoke growth index-V (SGI-V), and smoke risk index-VI (SRI-VI) according to a newly designed methodology. Spruce, Lauan, polymethylmethacrylate (PMMA), and polycarbonate (PC) were used for test pieces. Smoke characteristics of the materials were measured using a cone calorimeter (ISO 5660-1) equipment. The smoke performance index-V calculated after the combustion reaction was found to be 1.0 to 3.4 based on PMMA. Smoke risk by smoke performance index-V was increased in the order of PC, Spruce, Lauan and PMMA. Lauan and PMMA showed similar values. The smoke growth index-V was found to be 1.0 to 9.2 based on PMMA. Smoke risk by smoke growth index-V increased in the order of PMMA, PC, Spruce, and Lauan. COpeak production rates of all specimens were measured between 0.0021 to 0.0067 g/s. In conclusion, materials with a low smoke performance index-V and a high smoke growth index-V cause a high smoke risk from fire. Therefore, it is understood that the smoke risk from fire is high. It is collectively summarized by the smoke risk index-VI.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.3
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• pp.301-310
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• 2013

Jet fans are installed in road tunnels in order to maintain critical velocity when fire occurs. Generally the number of jet fans against fire are calculated by considering critical velocity and flow resistance by wall friction, vehicle drag force, thermal buoyance force and natural wind. In domestic case, thermal buoyance force is not considered in estimating the number of jet fans. So, in this study, we investigated the pressure loss due to the thermal buoyance force induced by tunnel air temperature rise and the impact of thermal buoyance force on the number of jet fans by the numerical fire simulation for the tunnel length(500, 750, 1000, 1500, 2000, 3500m) and grade (-1.0, -1.5, -2.0%). Considering the thermal buoyance force, number of jet fans have to be increased. Especially in the case of 100MW of heat release rate, the pressure loss due to thermal buoyance force exceed the maximum pressure loss due to vehicle drag resistance, so it is analyzed that number of 2~11 jet fans are needed additionally than current design criteria. Thus, in case of estimating the number of jet fans, it must be considered of thermal buoyance force induced tunnel air temperature rise by fire.

• Fire Science and Engineering
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• v.33 no.2
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• pp.9-19
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• 2019

Experiments on the combustion characteristics of untreated wood specimens and those treated with four types of silicone compounds were carried out using a cone calorimeter according to the ISO 5660-1 standard. 3-Aminopropyltrimethoxysilane (APTMS), 3-(2-aminoethylamino) propylmethyldimethoxysilane (AEAPMDMS), and 3-(2-aminoethylamino) propyltrimethoxysilane (AEAPTMS) were used as the silane compounds. The flame retardants were synthesized with sodium silicate and amino silane compounds. The measured time to ignition after combustion at an external heat flux of $50kW/m^2$ was 9 s to 11 s. Time to ignition was marked with a delayed value in the 3 s to 5 s range. The peak heat release rate ($HRR_{peak}$) was reduced by 5 to 20% compared with the uncoated specimen, and AEAPMDMS showed the highest initial fire risk. The total heat release (THR) was decreased by 1 to 22%. Compared to the untreated specimen, the fire performance index (FPI) of the specimens coated with silicone sol compounds increased by 1.5 to 2.2 fold. The fire growth index (FGI) of the AEAPMDMS specimen was increased by 30% and the others were decreased by 93 to 94%. Therefore, the fire risk of wood coated with silicone compounds was improved in terms of the heat risk properties.

• Fire Science and Engineering
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• v.22 no.3
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• pp.162-171
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• 2008

For a field of research to be an independent area of study, there must be a common paradigm that is shared by the members of the community. In addition. for establishment of identity in a study, several relating scientific communities should actively study and research, which lead to a new paradigm. Efforts to accomplish this purpose are found in Politics, Economics, and Psychology. Yet, the field of Fire Service Science have not yield these results which include active scientific communities, scholars and experts who research on the subject and exchange their expertises. New paradigm for the field is not established yet. Therefore, this research probes the origins of these problems and suggests a proper scientific paradigm and direction for establishment of identity of Fire Service Science in Korea's ambiance.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.124-132
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• 2010

To predict and analyze the rolling stock's fire growth is considered not only important factor in estimating hazard analysis of rolling stock, but also a primary factor in aspect of a rail load facility. Because it's could be regarded as a ignition source in risk assesment for the facility i.e. tunnel and station. However, currently, standardized method to predict and analyze the fire growth has not been completed yet. it is due to the fact that fire growth is not only depended on thermal property of interior materials, but also is affected dominantly by various factors such as ignition source (characterized by location, duration, and intensity), train running condition and in/exterior ventilation condition. Especially, ventilation condition is one of the most effective factor to affect fire growth in compartment space as noticed by under-ventilation fire condition. In this study, the effect of each ventilation condition on fire growth and load were examined through the numerical method through FDS (Fire Dynamics Simulator).

• Fire Science and Engineering
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• v.20 no.3 s.63
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• pp.85-95
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• 2006

Because the average span of human life is expanded by developing economy growth and medicine science elder population increases rapidly. According to that A first aid patient of demands grow, too so in a fire station. We have to prepare following these. First that the silver ambulance is in process of service is widely. second, medical teams and fire fighters construct unity Third, New curni culum makes under modern operating course. Forth, the problem that wireless paging system sets up and rums already. advances more effective. Fifth furthermore, we organize a private volunteer for an old age To connect that we enlarge total service for silver age. Through this fire fighting service. we are neloom to get more confidence and love.

• Fire Science and Engineering
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• v.23 no.4
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• pp.25-31
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• 2009

With rapid growths of economy and technology, structures and forms of buildings have been diversified and complicated. Buildings also have become higher and larger than ever before. As a result, more people use a building and more combustibles exist in the building. Without understanding of combustion characteristics and the establishment of a fire safety plan in case of a residential fire, it is expected great loss of lives and properties. In this study, experiments were carried out to promote an understanding of the combustion characteristics of combustibles in the building. Sofa and bed were used as combustibles in the experiment. Heat release rate of the sofa was about 1.9MW. Heat release rate of the bed was approximately 650kW.