• Title/Summary/Keyword: 확산연소

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The Study on the Countermeasure Plans about Leakage, Explosion and Fire Accidents of Atmospheric Storage Tank (옥외저장탱크 누출, 폭발 및 화재사고 대응방안에 관한 고찰)

  • Lee, Gab-Kyoo
    • Fire Science and Engineering
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    • v.30 no.6
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    • pp.48-56
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    • 2016
  • A crude oil leakage from a large atmospheric storage tank occurred on 4 April 2014 at 14:50 in Ulsan City, while storing the crude oil in the tank. Emergency Rescue Control Group was deployed in the scene. The company, Fire Service Headquarters and associated agencies got together in Command Post (CP) for discussing an effective corresponding strategy. Many solution plans were drafted in the debate such as power down, stopping the facilities, checking the density of inflammable gas, suppressing oil evaporation, moving the leaked crude oil to a nearby tank and a processing plant and avoiding marine pollution. All the solutions were carried out in cooperation with several agencies and partners. The oil leakage accident was successfully settled up within the process of responding, The Fire Service Headquarters and the company thought that the most important thing was the suppression of oil evaporation and the elimination of ignition source. With Fire Service Headquarters and several agencies' every effort, an explosion and a fire didn't occurred in the scene. This study suggest the improvement of the operating system in Emergency Rescue Control Group in case of petroleum leakage, explosion and fire accidents of atmospheric storage tank, different from a ordinary disaster. Assuming that petroleum leakage in atmospheric storage tank develop the explosion and fire accidents, the spreading speed of the flame and the burning time was experimented and compared with each other. Furthermore, this study concentrates on the effective field response plan prepared for the afterward explosion and fire accidents from petroleum leak in a storage tank, with the database experimented and analyzed in accordance with the angle of radiation in the foam nozzle and the pressure of pumping in a fire engine.

Study on the Analysis of Damage Patterns of Cellular Phone Batteries According to Energy Sources (에너지원에 따른 이동전화기 배터리의 소손패턴 해석에 관한 연구)

  • Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.25 no.6
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    • pp.21-26
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    • 2011
  • The purpose of this paper is to present the damage patterns of cellular phone (SCH_W830) batteries according to energy sources and have them utilized as data for the settlement of disputes between manufactures and consumers. The reliability was secured by maintaining the ambient temperature and humidity at $22{\pm}2^{\circ}C$ and 40~60 %, respectively. The voltage of the battery used for the tests was measured to be 4.18V between positive pole (+) and negative pole (-)(1), and 4.19 V between positive pole (+) and negative pole (-)(2). This study applied the Korean Industrial Standard (KS) to the flammability test of cellular phones due to a general flame applied to them and found that no damage occurred to the built-in battery even though the flame was applied to the cases of cellular phones for 30 seconds. From the results of immersing the cellular phones in the saline solution (NaCl, 0.9 %) for 180 seconds, it was found that there was a trace of carbonization and melting due to the heat caused by leaking current. It can be seen that when the cellular phones were heated for 70 seconds using a microwave oven (MWO), the areas containing the metal holder, recharging connector, antenna, etc., were melted and discolored and that other areas showed no particular problems. That is, while the external carbonization of cellular phones, built-in metals and dielectric materials, and damage and deformation of the battery terminal block, etc., occurred differently depending on the types of energy sources, the voltage showed comparatively constant characteristics. Therefore, it is thought to be possible to attribute the cause of damage to the battery by performing analysis taking into consideration comprehensively the characteristics of the flame spread pattern as well as the melting and deformation of metals.

Allometric Equations for Crown Fuel Biomass of Pinus koraiensis Stands in Korea (잣나무림의 수관연료량 추정을 위한 상대생장식 개발)

  • Kim, Sungyong;Jang, Mina;Lee, Byungdoo;Lee, Youngjin
    • Journal of Korean Society of Forest Science
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    • v.104 no.1
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    • pp.104-110
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    • 2015
  • The objective of this study was to develop allometric equations for the estimation of crown fuel biomass of Pinus koraiensis in Korea. A total of twenty four representative sample trees were destructively sampled in Gapyeong, Hongcheon, and Jeongseon. Crown fuels were weighed separately for each fuel category by size class and by living and dead. The results of this study showed that the needles contributed the largest biomass (16.6 kg, 34.7%), followed by live branches with size ranging from 2~4 cm (9.0 kg, 18.9%), 1~2 cm (6.6 kg, 13.8%), <0.5 cm (5.1 kg, 10.6%), 0.5~1 cm (4.9 kg, 10.3%), and dead branches (3.2 kg, 6.8%), while the live branches with 4 cm (2.4 kg, 4.9%) as the lowest. The adjusted coefficient of determination values were the highest ($R^2_{adj}=0.6021{\sim}9742$) and standard error of estimate were the lowest (S.E.E.=0.2018~0.7271) in allometric equation $lnWt={\beta}_0+{\beta}_1lnD$. The available fuels that are consumed during crown fires (i.e., needles and twigs with diameter less than 1 cm) comprised 55.6% of the total crown fuel biomass.

Enhanced Flame Retardancy of Cotton Fabric by Functionalized Graphene Oxide and Ammonium Polyphosphate (기능성화 산화 그래핀과 폴리인산암모늄을 이용한 직물 난연성 향상)

  • Ka, Dongwon;Jang, Seongon;Jung, Hyunsook;Jin, Youngho
    • Composites Research
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    • v.33 no.4
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    • pp.177-184
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    • 2020
  • Flame retardant(FR) clothes prohibit additional fire diffusion and make the personnel do their tasks without a hitch in a flammable environment. The existing FR clothes, however, are heavy and give high thermal fatigue. Therefore, it is strongly demanded to develop a light, convenient, and eco-friendly clothes. Recently, many works have been reported to make FR fabrics with phosphorus compounds, but their performance could not satisfy the specified criteria in appraisal standards of domestic and American FR clothes or combat uniforms. In this paper, two kinds of phosphorus compounds were applied to cotton fabric. Graphene oxide functionalized with a phosphorus-rich deep eutectic solvent and ammonium polyphosphate were coated on cotton fabric by eco-friendly padding procedure. The coated fabrics were analyzed with thermogravimetric analysis, vertical flame resistance test(ASTM D6413), cone calorimeter test(ISO 5660-1), and method of test for limited flame spread(ISO 15025). It was revealed that the as-made cotton with those two materials simultaneously had better flame resistance than the cottons with each one. Furthermore, an additional coating for hydrophobicity on the FR cotton was tried for better washing fastness.

Tritium Distribution in Some Environmental Samples-Rices, Chinese Cabbages and Pine Needles in Korea (국내 환경시료(쌀, 채소, 솔잎) 중 삼중수소의 분포)

  • Kim, Chang-Kyu;Cho, Yong-Woo;Han, Man-Jung;Pak, Chan-Kirl
    • Journal of Radiation Protection and Research
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    • v.17 no.2
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    • pp.25-35
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    • 1992
  • To evaluate tritium level in some environmental samples, tissue-free water tritium (TFWT) and tissue-bound tritium (TBT) were analyzed in rices, chinese cabbages and pine needles collected at 12 locations in Korea. The TFWT was recovered by freeze-drying of the samples and the TBT was obtained in the form of water by combustion of the dried samples. Tritium was measured by liquid scintillation counter. The concentrations of TFWT were in the range of $0.96{\sim}3.96 Bq/1,\; 0.83{\sim}3.40 Bq/1\;and\;1.02{\sim}3.01 Bq/1$ in rices, chinese cabbages and pine needles, respectively. The mean specific activity ratios (TBT/TFWT) were 0.94, 1.71 and 1.39 in rices, chinese cabbages and pine needles, respectiviely. This excess TBT in the samples may be attributed to the fact that the residence time of TBT in the plant is longer than that of TFWT. The specific activity ratio depends on the plant species, the exposed time to tritiated atmosphere, atmospheric moisture, temperature and diffusion factor.

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Estimation of Canopy Fuel Characteristics for Pinus densiflora Stands Using Diameter Distribution Models: Forest Managed Stands and Unmanaged Stands (직경분포모형을 이용한 소나무림의 수관연료특성 예측: 산림시업지 임분과 비시업지 임분에서)

  • Lee, Sun Joo;Kim, Sung Yong;Lee, Byung Doo;Lee, Young Jin
    • Journal of Korean Society of Forest Science
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    • v.107 no.4
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    • pp.412-421
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    • 2018
  • The objective of this study was to analyze the effects of forest management activities on canopy fuel characteristics for Pinus densiflora stands in South Korea. We used 1,085 managed stands data and 349 unmanaged stands data of the National Forest Inventory for this study, and it was estimated by using the Weibull function for the growth of stand and canopy fuel characteristics. Comparing the canopy fuel characteristics for the managed stands and unmanaged stands shows that the average canopy fuel load is about 14% higher than that of managed stands, and the canopy bulk density is also approximately 16% higher. The results of comparing growth projections for 40 years, 50 years and 60 years with the Weibull function are as follows: Over time, managed stands was predicted the maximum number of medium and large class diameter, while unmanaged stands was predicted maximum number of small and medium class diameter. From a fire fuel perspective, unmanaged stands are predicted to be of the type small class diameter and high density, which is a good condition for crown fire. In addition, Canopy fuel load, Canopy bulk density is relatively higher than managed stands, indicating that the possibility of high crown fire hazard.

Effects of Forest Tending Works on the Crown Fuel Characteristics of Pinus densiflora S. et Z. Stands in Korea (숲가꾸기 사업이 소나무림의 수관연료특성에 미치는 영향)

  • Kim, Sungyong;Lee, Byungdoo;Seo, Yeonok;Jang, Mina;Lee, Young Jin
    • Journal of Korean Society of Forest Science
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    • v.100 no.3
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    • pp.359-366
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    • 2011
  • The objective of this study was to analyze the changes of crown fire hazard possibility from the effects of forest tending works (FTW) in Pinus densiflora stands in Korea. The study sites were located in Youngju (FTW) and Bonghwa (Control) areas. Ten representative sample trees were destructively felled at each areas to analyze the crown fuel characteristics. The results of this study showed that crown fuel moisture content in Youngju and Bonghwa areas were 103.6% and 104.4%, respectively. The needles and twigs with less than 1cm diameter accounted 50.3% of the total crown fuel load in Youngju area and 62.0% in Bonghwa area. On the other hand, it was observed in Youngju that the canopy bulk density was $0.11kg/m^3$ lower but have 1.3 m higher average canopy base height therefore having a possibility of lower crown fire hazard as compared to Bonghwa that had higher canopy bulk density and lower canopy base height.

Analysis of the Effect of Forest Fires on the Mineralogical Characteristics of Soil (산불 영향에 따른 토층의 광물학적 특성 변화에 관한 연구)

  • Man-Il Kim;Chang-Oh Choo
    • The Journal of Engineering Geology
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    • v.33 no.1
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    • pp.69-83
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    • 2023
  • Forest fires increase the risk of subsequent soil erosion and mass movement in burned areas, even under rainfall conditions below landslide alert thresholds, by destroying plants and vegetation and causing changes to soil properties. These effects of forest fires can alter runoff in burned areas by altering soil composition, component minerals, soil water repellency, soil mass stability, and soil fabric. Heat from forest fires not only burns shallow organic matter and plants but also spreads below the surface, affecting soil constituents including minerals. This study analyzed X-ray diffraction and physical properties of topsoil and subsoil obtained from both burned and non-burned areas to identify the composition and distribution of clay minerals in the soil. Small amounts of mullite, analcite, and hematite were identified in burned soils. Vermiculite and mixed-layer illite/vermiculite (I/V) were found in topsoil samples from burned areas but not in those from non-burned areas. These findings show changes in soil mineral composition caused by forest fires. Expansive clay minerals increase the volume of soil during rainfall, degrading the structural stability of slopes. Clay minerals generated in soil in burned areas are therefore likely to affect the long-term stability of slopes in mountainous areas.