• Journal of the Society of Disaster Information
• /
• v.17 no.3
• /
• pp.617-626
• /
• 2021

Purpose: The purpose of this study is to evaluate the fire srpead risk of building exterior and roofing materials due to the firebrand of forest fire occurring in the urban areas. Method: In order to achieve this research purpose, by selecting building materials used for exterior and roofing materials of buildings, the time to ignition, total heat release, and heat release rate were investigated, and a forest fire firebrand system was established to the possibility of fire spread was confirmed. Result: As a result of the cone calorimeter test, the roofing material had a similar or faster ignition time due to radiant heat compared to the exterior material with the steel plate exposed to the outside, and showed a higher heat release rate and total heat release than the exterior material. Although it was affected by the flammable material, it was confirmed that it did not spread easily due to the limited amount of combustible material, and carbonization marks appeared inside. Conclusion: The cone calorimeter test method has been shown to be useful in understanding the combustion characteristics of building materials by radiant heat, but the fire spread due to a firebrand in a forest fire is directly affected by the flame due to the ignition of surrounding combustibles, so finding a direct correlation with the cone calorimeter method is difficult. It is judged that the roof material may be more vulnerable to the spread of fire due to the fire than the exterior material.

• Journal of Power System Engineering
• /
• v.15 no.1
• /
• pp.11-17
• /
• 2011

본 연구는 라디칼 착화(Radical Ignition이하 RI) 기술을 적용한 부실직분식 CNG(Compressed Natural Gas) 엔진의 구동특성에 관한 것이다. 실험엔진은 단기통 디젤엔진을 개조하여 사용하였으며, 이는 부실식 디젤엔진처럼 연소실이 주실과 부실로 나누어져 있다. 부실에 분사된 CNG는 스파크플러그로 점화하며, 부실로 부터의 연소가스가 주실 희박 혼합기를 시켜 구동하는 엔진이다. RI 기술은 연소속도를 향상시킬 수 있다. 본 연구는 주로 저부하 RI-CNG 엔진의 성능을 연구하였다. 연료분사기간은 9 ms, 공기과잉률은 1.0, 1.2, 1.4로 하였다. 연료분사시기는 엔진의 배가밸브가 닫히는 ATDC $20^{\circ}CA$ 부터 $120^{\circ}CA$ 사이로, $20^{\circ}CA$ 간격으로 지각시켜 가며 실험하였다. 본 연구는 연료분사시기 및 공기과잉률이 연소최고압력 ($P_{max}$), 연소최고압력시기(${\Theta}_{pmax}$), 도시평균유효압력(IMEP), 사이클 변동계수($COV_{imep}$), 연소속도에 미치는 양향 등을 구하고 분석하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.426-432
• /
• 2017

An experimental and numerical study on shock attenuation in a solid by a subminiature flyer impact was conducted to determine the performance of a subminiature exploding foil initiator such as, flyer velocity and impulse loading. The obtained attenuation pattern shows the possibility to determine the critical flyer velocity for initiating the miniaturized pyrotechnic unit by figuring out shock intensity and duration according to flight characteristics.

• Fire Science and Engineering
• /
• v.23 no.2
• /
• pp.111-116
• /
• 2009

17 kinds of fire resistant paint which are currently used were painted on the MDF(middle density fiber board), which suitable to the regulation of Fire Service Act. And we investigate a ignition delay effect under a exposure condition of radiative heat of fire. Radiative heat flux was controlled from $10kW/m^2$ to $30kW/m^2$ using the cone heater. Ignition time, ignition type and surface temperature of the sample were measured. Based on the experimental result, critical heat flux of the fire resistant paint treated sample was $10kW/m^2$ and there were no ignition delay effect above the $30kW/m^2$. And it was found that it will be difficult to expect the fire resistant effect above $400^{\circ}C$ of sample surface temperature.

• Journal of the Korean Institute of Gas
• /
• v.2 no.2
• /
• pp.55-60
• /
• 1998

In this study, we investigated the dust explosion characteristics by determining minimum ignition energy and explosion limit for this experiment, we used pine-tree dust which was used widely for the filler of thermosetting resin. The experiment was accomplished according to the variation of discharge gap, dust concentration, particle size and humidity. The result of this experiment are as follows; (1) The relation between the discharge gap and ignition energy was that ignition energy decreased according as the discharge gap became small, but increased when the discharge gap was below 4mm and suddenly became infinite when the discharge gap was below. So, we knew that this infinite value was limit discharge gap. (2) When the dust concentration increase and the particle size became microscopic it was easy to explore and in the same particle size, if the humidity increase the minimum ingnition energy decreased.

• YAKHAK HOEJI
• /
• v.13 no.1
• /
• pp.38-42
• /
• 1969

Chloropentammine chromium(III) chloride를 출발물질로 하여 여러가지의 thiocyanatoammine계 착화합물을 합성하는 실험에 있어서 그 수득량이 예상보다 매우 적고 그 염의 모액이 농적자색이라는 점으로 보아 그 모액중에 어떠한 다른 착화합물이 다량 형성되어 있으리라고 추측하여 그 분리를 시도하였다든바 미려한 적자색의 결정을 얻었다. 그리고 분석에 의하여 이 물질이 potassium hexathiocyanatochromate(III) 임을 증명하였다. Cr$^{+++}$ 의 thiocyanate 착화합물형성에 관하여는 Niel Bjerrm$^{(8)}$에 의한 보고문이 있고 또 이들의 제법으로서는 Roesler$^{(9)}$들에 의하여 Potassium chromium alum에서부터 이 물질을 만드는 방법만이 보고되어 있을뿐이다. 따라서 Chloropentammine chromium(III) chloride에서 부터 이 물질을 만드는 이 새로운 방법이 이러한 화합물들의 제법으로서 앞으로 이용될 수 있는것으로 사료한다. 제조 방법: Chloropentammine chromium(III) chloride 3g을 KSCN 24g, 빙초산 24ml및 물 48ml의 혼합수용액에 현탁시킨 혼합물을 처음에는 잘 교반하면서 가온하고 다음 완전히 용해될때까지 끊인다. 냉각시킨 다음 생성된 증황색의 침반 Thiocyanatopentammine chromium(III) thiocyanate를 여과하고 여액 65ml에 KSCN 50g을 추가하여 완전용해시킨다. 이 용액을 방냉시키면 적자색의 미려한 결정이 석출되므로 이 결정을 여과하여 ethanol로 세척하고 진공 desiccator중에서 건조시켰다. 수득량 1.2~1.3g.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.1531-1532
• /
• 2015

본 논문에서는 태양광 발전설비 보급에 따라 증가하고 있는 태양광 접속함의 화재 사례를 분석하고 착화재현실험을 통하여 전기화재 위험성을 분석하였다. 전압 및 전류에 따른 태양광 접속함의 온도변화 특성을 분석하였으며, 특히 태양광 접속함의 트래킹에 의한 착화실험과정 통하여 전기적 특이점을 분석하고 트래킹에 의한 전기화재 예방대책을 제시하였다.

• Journal of Korean Institute of Fire Investigation
• /
• v.9 no.1
• /
• pp.27-34
• /
• 2006

2004년 2월~5월까지 대구시 달서구 00동 소재에서 연쇄방화가 발생 되어 수사를 하여 오던 중 우리경찰서에서 다방면으로 수사하여 차량화재 방화범 000를 검거 후 기소한 상태에서 공판이 진행되던 과정에서 변호인 측에서 일회용 라이터로는 차량을 착화 또는 발화의 가능성이 현저히 어렵다는 이유로 피고인의 무혐의를 주장하는 변론이 제기되어 00지방검찰청 000 담당검사의 요청에 의하여 혐의를 입증하고 검증할 수 있는 자료를 제출하고 검증자료가 없으면 본 건의 조건에 따르는 실험을 실시하고 감정결과를 제출하라는 지휘에 의거 우리경찰서 과학수사팀에서는 차량(프라이드)을 1대 구입하여 지방경찰청 과학수사팀, 국립과학수사구소 남부분소 이공학실 화재 연구실과 연계하여 차량화재 실험을 실시하고 실험과정 및 발화 행태와 양상을 구체적으로 증명할 수 있는 자료를 조사연구 분석하고 국립과학수사 연구소에서는 00지방검찰청에 촬영 데이터 원본영상과 촬영물, 그리고 감정서를 작성, 실험 결과를 문서화하여 제출하여 혐의를 입증한 사례 연구로 피의자에 대한 혐의 입증시 상황이나 정황 증거보다 실체적 진실증거의 중요성을 재인식 하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.1
• /
• pp.67-73
• /
• 2011

The purpose of this study is to investigate experimentally the spray-atomization and combustion-emission characteristics of biodiesel-DME blended fuel. In this study, two types of test fuels pure biodiesel (BD100) and blended fuel (B-DME20) were used, and the spray and combustion characteristics of different fuel compositions were analyzed. DME constitutes 20% and biodiesel constitutes 80% (by mass fraction) of the blended fuel. The overall spray characteristics, spray tip penetration, and cone angle were evaluated using frozen spray images. In addition, the combustion and emission characteristics were analyzed on the basis of the evaluated data for a single-cylinder CI engine with common-rail injection system. It was revealed that the injection profiles of both the test fuels for a given injection pressure showed similar trends. However, the injection profiles of the blended fuel (B-DME20) indicated shorter ignition delay than those of biodiesel.

• Applied Chemistry for Engineering
• /
• v.4 no.1
• /
• pp.171-177
• /
• 1993

In decontamination process to remove radioactive materials of reactor cooling system, the metal ions dissolved by organic acids in decontamination solution are separated by use of ion exchange resin in the column. However, organic acids in decontamination solution decrease the apparent affinity of the resin to metal ions. In light of this, some experiments were carried out on the Amberlite IRN-77 cation resin with cobalt and iron to gain a better understanding of the complexation effects on the ion exchange process. Experimental results showed that EDTA among organic acids used as chemical decontaminants predominantly caused reduction of ion exchange capacity of cobaltous ion to resin since this reagent formed the complex with the cobaltous ion stronger than that with the ferrous ion. In contrast, the effects of oxalic acid and citric acid were found to be negligible. And, single and two-component nonlinear equilibrium relationships of the metal ions were established using experimental data.