• Fire Science and Engineering
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• v.34 no.3
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• pp.141-149
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• 2020

The Korea Industrial Standards (KS) stipulates methods and test procedures for measuring the horizontal combustibility of cellular plastics exposed to small flames (KS M ISO 9772:2018) and recommendations regarding the magnetic digestion of extruded polystyrene insulation (XPS) for measurement results (KS M 3808:2020). Although products that are certified to conform to KS standards must have burning characteristics (self-extinguishing), they are incinerated and spread by welds at construction sites, causing significant human and property damages. In this study, XPS produced by five companies, certified by KS, and sold in the market were purchased and tested for ignition and diffusion caused by a weld bullion at a construction site. The results showed that the five products had differences in performance. Three out of the five products were found to be self-saturated, but the other two were easily ignited and diffused, making it difficult for them to be self-extinguishing. Based on the result of this experimental investigation in line with the KS regulations, all the three types of products, including two types of products that were incinerated through weld defects, were found to be non-self-extinguishing, as specified in KS M 3808.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.178-178
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• 2013

본 연구는 산림 내 주요 시설물 주변의 소나무, 리기다소나무, 해송, 잣나무, 굴참나무낙엽 5종 및 소나무광솔 등 주요 산불연료에 대하여 연소특성을 분석하고자 착화특성과 전파특성을 실험 한 결과, 발화온도의 경우 소나무낙엽($285^{\circ}C$)이 가장 낮게 측정되어 발화위험성이 가장 높은 것으로 나타났으며, 착화시간의 경우 굴참나무낙엽(발화온도 $305^{\circ}C$)이 3초로 가장 빠르게 나타났고, 화염유지시간의 경우 굴참나무낙엽이 가장 긴 것으로 나타났다. 또한, 전파특성 실험결과 소나무 광솔이 총열방출량 $72MJ/m_2$, 평균열방출율 $40KW/m_2$, 최대열방출량 $206KW/m_2$로 가장 높았으며, 두번째는 소나무낙엽으로 나타났다. 따라서, 실제 산불에서도 소나무광솔과 소나무낙엽이 화염전파에 더 영향을 줄 것으로 사료되었고, 또한, 연료별 탄소배출량 분석 결과 평균$CO_2$방출량이 가장 큰 수종은 리기다소나무낙엽(1.33kg/kg)이며, 평균CO방출량이 가장 큰 수종은 굴참나무 낙엽(0.075kg/kg)으로 나타났다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.140-143
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• 2011

산불의 확산형태 중 지표화 확산을 방지하기 위해 대표적인 진화방법으로는 방화선을 구축하는 것이다. 지표화는 산림의 연료중 낙엽층, 잔가지 등 지표면의 연료층이 열분해되면서 확산되기 때문에 방화선 구축을 통해 연료층을 제거하면 지표화 확산을 저지할 수 있다. 하지만 방화선 구축 폭에 따라 산불확산 방지 효과가 크게 달라질 수 있으므로 적정한 방화선 구축 폭을 설정하여야 한다. 본 연구에서는 적정 방화선 구축 폭을 살펴보기 위해 풍동시험장치를 이용하여 풍속 0, 1, 2, 3m/s조건에서 지표화 화염으로부터 이격 거리에 따른 온도측정과 함께 방화선 구축 폭에 따른 확산가능 여부를 평가하였다. 50cm 폭의 소나무 낙엽에 대한 풍속별 지표화 방화선 구축 실험결과, 풍속 3m/s에서 화염으로부터 소나무 낙엽의 착화온도인 $311^{\circ}C$에 도달하는 거리가 약 0.65m로 나타났고 풍속이 낮을수록 착화온도 도달거리가 줄어드는 것을 알 수 있다. 실제 0.6m 방화선 구축의 경우, 화염이 계속 확산되었고 0.65m 이상의 방화선 구축시에는 화염확산이 이루어지지 않았다. 따라서 향후, 수치해석을 이용한 열유속 평가 결과와 함께 본 연구의 실험결과와 비교평가 함으로써 지표화 산불확산 방지를 위한 적정 방화선 구축 폭 산정을 평가하고자 한다.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.5
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• pp.15-21
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• 2015

The thermal decomposition characteristics of the ZPP(Zirconium/Potassium perchlorate), widely used as a primary charge of initiators, were investigated by differential scanning calorimetry(DSC). The DSC results with different heating rates were elaborated with AKTS-Thermokinetics software for the determination of the kinetic parameters of the thermal decomposition of ZPP. There was good agreement between the experimental and the simulation curves, based on the determined kinetic parameters, which indicates the validity of the kinetic description of the thermal decomposition process of ZPP.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.6
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• pp.628-633
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• 2012

It was found that the pure hydrogen-air pre-mixture was self-ignited at a high compression ratio without any assisting method in room temperature, thus refuting the preconception that compression ignition of hydrogen engine was impossible. Therefore, in order to analyze the correlation of compression ignition condition at cold start with hydrogen HCCI engine clearly, the possibility of compression igniting compression ratio is investigated with the change of equivalence ratio and engine speed, experimentally. As the results, it is confirmed that the possibility of compression-igniting compression ratio at cold start was decreased by increasing equivalence ratio due to decreasing auto-ignition temperature. In addition, it is grasped that the possibility of compression-igniting compression ratio at cold start is decreased around 14.9% by increasing engine speed at same supply energy.

• Journal of the Korean Chemical Society
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• v.13 no.1
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• pp.16-24
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• 1969

Ni, Co, Zn, Cd, Mn, Mg, Ca, Sr, Ba 등의2가 금속과 U(VI) 및 V(IV)의 이온이 만드는 $MCup_2$ 조성의 cupferrates 착화합물에 관하여, 그 용해도가 좋은 dioxane-$H_2O$, methanol-$H_2O$, ethanol-$H_2O$ 및 2-propanol-$H_2O$의 혼합용매를 사용하여, 그들의 몰분율을 변화시키면서 제 1, 제 2 및 전체의 열역학적인 안정도상수를 전위차적정법에 의하여 측정하고, 안정도 상수와 유기용매의 몰분율에 관한 실험식을 얻었다. 한편 분광광전법에 의하여 가능한 cupferrates의 전체 안정도 상수를 측적하여 이들과 비교하였다. 2가 금속 cupferrates의 안정도상수는 위에 적은 금속의 순서로 감소하고, 이들의 log $K_1$은 log $K_2$보다 크지만, U(VI)과 V(IV)의 cupferrates는 log $K_1$$K_2$여서 1:1과 1:2 착화합물 사이에 구조 변화가 있는듯하다. 몰분율이 영인 점에서의 안정도상수는 금속 cupferrates의 수용액에서의 용해반응의 평형상수에 해당하며, 금속의 착화합물의 안정도상수와 용해도와는 무관하고, K<$10^5$인 cupferrates에 관해서는 분광전법을 적용하기 어렵다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.4
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• pp.371-377
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• 2011

The aim of this study is to investigate the effects of aromatics and T90 temperature for high cetane number (CN) of diesel fuels on combustion and exhaust emissions in low-temperature diesel combustion in a 1.9 L common rail direct injection diesel engine at 1500 rpm and 2.6 bar BMEP. Four sets of fuels with CN 55, aromatic content of 20% or 45% (vol. %), and T90 temperature of $270^{\circ}C$ or $340^{\circ}C$ were tested. Given engine operating conditions, all the fuels showed the same tendency of decrease of PM with an increase of an ignition delay time. At the same ignition delay time, the fuels with high T90 produced higher PM. At the same MFB50% location the amount of NOx was similar for all the fuels. Furthermore, at the same ignition delay time the amounts of THC and CO were similar as well for all the fuels. The amount of THC and CO increased with an extension of the ignition delay time mainly because of the increase of fuel-air over-mixing.

• Fire Science and Engineering
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• v.24 no.3
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• pp.52-57
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• 2010

Fire protection countermeasure were considered on the straw thatched roof and wooden structure. For the fire resistant treatment, rice straw was soaked in the fire resistant liquid with different soaking time. After treatment, some rice straw sample was washed with water then the rice straws were tested to check the fire resistance performance. And the wood was soaked in the fire resistant liquid at an atmospheric pressure, vacuum-pressure condition and painted with brush on the surface. To analyse the fire resistant performance of rice straw, ignition delay time was measured under the radiant heat flux of cone heater. And the fire resistant performance of wood samples were tested with 45 degree fire resistant test apparatus and cone heater. Based on the cone heater test, the rice straw which most easily ignitable material shows the longer ignition delay time than not treated ones and even in the water washed straw show a longer ignition delay time than not treated ones. And fire resistant treated woods of vacuum-pressure treated sample showed the most excellent performance on fire resistance. And the fire resistant treated by brush and soaking showed a longer ignition delay time than not treated ones. From this experiment, it was found that a fire resistant treatment of rice straw and wood of the house can be protected from the fire spread.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.72-79
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• 1987

In this paper, an investigation of the property of blended fuel oil, combustion characteristics and engine performance was made, in case blended fuel oil(light oil+heavy oil) was used in a home-made precombustion diesel engine for small-sized fishing boat. The results may be summarized as follows: 1. The specific gravity was linearly increased in accordance with the increase in heavy oil ratio in blended fuel oil, and the relationship between viscosity and temperature was coincided with the formula of Walther-ASTM, and the CCAI, the ignition quality index, was increased nearly as a straight line of the gradient 1.0. 2. The ignition delay was slightly increased below 810 of CCAI(blending ratio to be 60% of heavy oil), but remarkably increased above 810 of CCAI. Therefore, it was considered that the practicable value of CCAI, ignition quality of blended fuel oil, was more than 810. 3. The maximum combustion pressure was increased until blending ratio of heavy oil was raised up to 40%. On the contrary, it came to be decreased at that ratio, with smoke emissions remarkably increasing above 60%. Therefore, it was found in this experiment that the best practicable limit of heavy oil blending ratio was around 50% for saving fuel costs with least smoke emissions.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.26-26
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• 1987

In this paper, an investigation of the property of blended fuel oil, combustion characteristics and engine performance was made, in case blended fuel oil(light oil+heavy oil) was used in a home-made precombustion diesel engine for small-sized fishing boat. The results may be summarized as follows: 1. The specific gravity was linearly increased in accordance with the increase in heavy oil ratio in blended fuel oil, and the relationship between viscosity and temperature was coincided with the formula of Walther-ASTM, and the CCAI, the ignition quality index, was increased nearly as a straight line of the gradient 1.0. 2. The ignition delay was slightly increased below 810 of CCAI(blending ratio to be 60% of heavy oil), but remarkably increased above 810 of CCAI. Therefore, it was considered that the practicable value of CCAI, ignition quality of blended fuel oil, was more than 810. 3. The maximum combustion pressure was increased until blending ratio of heavy oil was raised up to 40%. On the contrary, it came to be decreased at that ratio, with smoke emissions remarkably increasing above 60%. Therefore, it was found in this experiment that the best practicable limit of heavy oil blending ratio was around 50% for saving fuel costs with least smoke emissions.