• Title/Summary/Keyword: fire period

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Diffusion and Disperision of Injected $CO_2$Gas Into the $N_2$Gas Flow ($N_2$기체의 흐름에 주입된 $CO_2$기체의 확산 및 분산)

  • 김유식;안대영
    • Fire Science and Engineering
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    • v.16 no.3
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    • pp.1-7
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    • 2002
  • Diffusion and dispersion of injected $CO_2$gas into the $N_2$ gas flow are complex. In the packed column with porous particles the axial dispersion and the extra-particle mass transport as well as the intra-particle mass transport are involved. The pulse spreads by stationary diffusion during the period of arrested flow. Hence, the effect of axial dispersion, and of entrance and exit, as well as that of intraparticle convection should be eliminated during the period. The effective diffusivity was determined experimentally by using the gas chromatography, which is to arrest the gas flow during the period after injecting the pulse. This experiment method hasn't been used often in the field. Effective diffusivities are raised with temperature increasing, and it is quite satisfied com-pared to literature values. In this study, the calculated data of gaseous chemical for extinguish fires could be helpful to appreciate several physical phenomenons. Also, it could be expected that, the calculated data of this study might be very useful for development of excellent gaseous chemical for extinguish fires and improvement of its efficiency.

The Vulnerability Assessment Forest Fire in Jeju to Climate Change using the VESTAP (VESTAP을 활용한 기후변화에 따른 제주도 산불 취약성 평가 연구)

  • Lim, Chae-Hyun
    • Fire Science and Engineering
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    • v.30 no.1
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    • pp.57-62
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    • 2016
  • This study evaluated the risk of forest fires due to climate change in Jeju using the VESTAP. The study primarily aimed at assessing the risks posed to Jeju city and Seogwipo city, and uses actual and projected date from the period of 2000's to 2040's based on RCP 8.5 scenario. Forest fire vulnerability throughout Jeju-do was determined through the standardization of vulnerability index. The highest vulnerability was determined for the towns of Chuja-myeon, Udo-myeon, two downtown areas in Jeju city, Daejeong-eup, and five downtown areas in Seogwipo city, respectively.

Effect of indoor fire hydrant hose loading method on rapid fire suppression (옥내소화전 호스 적재 방법이 신속한 화재진압에 미치는영향)

  • Jeon, Jai-In
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.5
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    • pp.535-539
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    • 2022
  • This study analyzed the efficient hose loading method for indoor fire hydrants, and the experimental results are as follows. An effective fire hose loading method is to be derived through an experiment comparing the fire hose loading method of an indoor fire hydrant and the speed of fire suppression. When the fire hose was loaded by folding, it took an average of 33 seconds to load the fire hose, and for the hangyeopsal, it took an average of 69 seconds to load the fire hose, showing a significant difference. First, in the folding hose deployment experiment, subjects A, C, D, and E showed similar values from 34 seconds to 37 seconds, respectively. The reason seems to be the result of the fact that the fire hose was not twisted when unfolding, and that it was possible to deploy the hose smoothly. Subject B showed the lowest deployment time at 25 seconds, which seems to be the result of B's experience in deploying the fire hose. Second, in the hose unfolding experiment, subjects A, B, C, and E had a similar time period of 44 to 76 seconds, respectively. However, the test subject D was significantly higher at 110 seconds. The reason is that the attempt to prevent hose kinking when deploying the fire hose and the unstable psychological state through tension are judged to increase the fire hose deployment time.

Variation of Material Properties of Fire-killed Timber - Impact of Time on Degradation of Mechanical Properties - (산불 피해목의 재질변화에 관한 연구(II) - 산불 피해 소나무의 경시적 재질변화 -)

  • Park, Jung-Hwan;Park, Byung-Soo;Kim, Kwang-Mo;Lee, Do-Sik
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.1
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    • pp.30-35
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    • 2008
  • Degradation of mechanical properties of fire-killed Korean red pine has been investigated after death in 5 years period. Impact bending absorbed energy was the most sensitive property by elapsed time after forest fire. It is an indication of incipient decay of the wood and can be useful indicator to monitor any change of mechanical property of fire-killed tree after death. Degradation of mechanical properties was more pronounced in sapwood than heartwood. Impact bending absorbed energy was more reduced than any other properties in both sapwood and heartwood, while compressive strength was least impacted by elapsed time after forest fire. It is recommended that the fire-killed Korean red pine can be harvested in one year after the fire for industrial uses by considering decay and consequent changes of mechanical properties.

A Study on the Fire Resistance Performance of Wood Framed Lightweight Wall which Including a Middle Lintel (중인방을 포함한 목골조 경량벽체의 내화성능에 관한 연구)

  • Yeo, In-Hwan;Cho, Bum-Yean;Min, Byung-Yeol;Yoon, Myung-O
    • Fire Science and Engineering
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    • v.25 no.3
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    • pp.91-98
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    • 2011
  • This study is about fire resistance performance of wood framed lightweight wall including a middle lintel as a traditional wall form in Korea. The target wall is non-loadbearing system which constructed with $38{\times}89$ mm ($2"{\times}4"$) wood frame and fireproof gypsum board covering, including a middle lintel made of $150{\times}150$ mm section glue-laminated timber. As a test results, all specimens have showed fire resistant performance over 90 minutes and tests were maintained until flame occuring on Specimen-l, 2, 3 at 91 min, 97 min and 98 min respectively. Fire resistance of the heat side gypsum board was 45 minutes and charring rate of middle lintel was equivalant with that of usual timber. The wood stud inside wall system showed relatively quick combution characteristic when exposed to high temperature with no temperature rising delaying time caused by moisture evaporation because of the dehydration preceded during the early period of fire side gypsum board resist to heat.

Accomplishment Analysis of the Fire Fighting and Safety Research Development Program Supported by Ministry of Public Safety and Security (2012-2014) (국민안전처 소방안전분야 연구개발사업(2012년~2014년)의 성과분석)

  • Chung, Jae-Han;Han, Yong-Taek
    • Fire Science and Engineering
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    • v.30 no.4
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    • pp.141-147
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    • 2016
  • The fire fighting and safety research development program supported by Ministry of Public Safety and Security is composed of fire prevention and alert technology research, special disaster response technology research, and rescue and disaster-field response safety technology research. The principal accomplishment indices of this research program are (1) patent submitting or registration; (2) field test, ensuring performance criteria for commercialization, development of prototype, registration of software, royalty of technology-transfer; (3) the task to be carried out in a published research paper, and number of applied policies; and (4) the study period of task performance of employment and incubated high-technology manpower. Therefore, this study analyzed the performance result of a patent, research paper, and software registration of the fire-fighting and safety R&D program supported by Ministry of Public Safety and Security from 2012 to 2014.

Effects of Forest Fire on the Forest Vegetation and Soil(IV) (황폐산지(荒廢山地)에서의 산불이 삼림식생(森林植生) 및 토양(土壤)에 미치는 영향(影響)에 관(關)한 연구(硏究)(IV))

  • Woo, Bo-Myeong;Lee, Heon-Ho
    • Journal of Korean Society of Forest Science
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    • v.78 no.3
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    • pp.302-313
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    • 1989
  • To investigate the effects of forest fire on the change of vegetation and soil conditions by the lapse of time, the 5th soil survey and vegetation analysis were carried out in July of 1988 at the rocky areas of Mt. Kwanak, where ground fire broke out 5 years ago. Three-year increasing trends of organic matter content, the value of pH, and total nitrogen content stabilized after the restoration of the vegetation. By the comparison of the occurrences of the species for 5 years after the forest fire, woody and herbaceous plants were categorized into 4 groups, i,e., invasive, sensitive, tolerant, and neutral species to the forest fire. Although such diversity indices as the species diversity and similarity index indicate that the restoration of damaged vegetation to the original species composition was proceeded for the period, the restoration of vegetation to the original crown closure and tree growth was not proceeded yet.

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Effects of job satisfaction and spouse support on parenting stress in female fire fighters with preschool-aged children (취학 전 자녀를 둔 여성소방공무원의 직무만족도와 배우자 지지가 양육스트레스에 미치는 영향)

  • Che, Ga-Young;Baek, Mi-Lye
    • The Korean Journal of Emergency Medical Services
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    • v.19 no.1
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    • pp.87-98
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    • 2015
  • Purpose: Job satisfaction, spouse support, parenting stress, and the factors that influence parenting stress in female fire fighters with preschool-aged children were examined. Methods: Data were collected from 180 female fire fighters who worked at the fire station from June to July 2013 and had preschool-aged children. Data were analyzed using SPSS WIN 21.0. Results: Average job satisfaction was 2.81, spouse support was 3.54, and parenting stress was 3.61. Parenting stress was negatively correlated with spouse support and job satisfaction. Job satisfaction and spouse support were positively correlated. Factors influencing parenting stress included employment period (${\beta}$=0.093, p <.05), a husband who is not a fire fighter (${\beta}$=-8.971, p <.05), having three children (${\beta}$=27.395, p <.05), delegating childcare to relatives (${\beta}$=9.605, p <.05), income (${\beta}$=-0.920, p <.05), and spouse support (${\beta}$=-0.589, p <.05). Conclusion: To reduce parenting stress and increase job satisfaction, female fire fighters with preschool-aged children should be assigned to stable administrative work instead of stressful on-site work. Husbands who are fire fighters should take advantage of paternity leave, implemented by the Ministry of Public Safety and Security, to increase their active participation in parenting.

A Study on the Possibility of Ignition by Disposable Lighter (사례를 통한 화재사(火災死)의 이해)

  • Jae, J.J.;Lee, C.W.;Keon, H.S.;Son, J.B.;Lee, J.I.;Choi, D.M.
    • Journal of Korean Institute of Fire Investigation
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    • v.10 no.1
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    • pp.59-75
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    • 2007
  • The causes of the fire casualties were the heat burns, contacted by flame, before the period of industrialization. According to the economic has been developed drastically since 1990, residing space has been become bigger and sophistication and interior finishing materials have been diversified. Therefore, the suffocation casualties, caused by inspiration of toxic combustion gases, have been more increased than the flame casualties in recently. Also, the arson casualties have been increasing with the increasing of insurance crime to take the Insurance money. According to National Emergency Management Agency announcement, 31,778 fires was occurred nationwide in 2006 and the total casualties were 2,180 occurred. 446 persons were died among them. Because the exact investigation of fire, occurred the death, is very especially important that civil and criminal cases will be happened. Therefore, we studied about the cause of fire, the place of origin, and the group of casualties age on the axies of fires, which were occurred recently. And the identification method of fire casualties, the human behavior characteristic, the flame casualties and the suffocation casualties at fire scene.

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