• Title/Summary/Keyword: Fire Point

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STRUCTURAL TEST AND ANALYSIS OF RC SLAB AFTER FIRE LOADING

  • Chung, Chul-Hun;Im, Cho Rong;Park, Jaegyun
    • Nuclear Engineering and Technology
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    • v.45 no.2
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    • pp.223-236
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    • 2013
  • In the present study the behavior of fire and the residual strength of fire-ignited RC slabs are investigated by experimental tests and numerical simulations. The fire tests of RC slabs were carried out in a furnace using the ISO 834 standard fire. The load capacity of the cooled RC slabs that were not loaded during the fire tests was evaluated by additional 3 point bending tests. The influence of the proportion of PP (polypropylene) fibers in the RC slabs on the structural behavior of the RC slabs after the fire loading was investigated. The results of the fire tests showed that the maximum temperature of concrete with PP fiber was lower than that of concrete without PP fiber. As the concrete was heated, the ultimate compressive strength decreased and the ultimate strain increased. The load-deflection relations of RC slabs after fire loading were compared by using existing stress-strain-temperature models. The comparison between the numerical analysis and the experimental tests showed that some numerical analyses were reliable and therefore, can be applied to evaluate the ultimate load of RC slabs after fire loading. The ultimate load capacity after cooling down the RC slabs without PP fiber showed a considerable reduction from that of the RC slabs with PP fiber.

Study on the Concept of Monarch-fire(君火) and Ministerial-fire(相火) in Zhu Dan-Xi(朱丹溪)'s Ministerial-fire Theory(相火論) (주단계(朱丹溪) 상화론(相火論)의 군화(君火) 상화(相火)의 개념에 대한 고찰)

  • Lee, Yong-Bum
    • Journal of Korean Medical classics
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    • v.27 no.4
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    • pp.29-38
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    • 2014
  • Objectives : In ministerial-fire theory(相火論) of Zhu Dan-Xi(朱丹溪), the meanings of monarch-fire(君火) and ministerial-fire(相火) described in papers published nowadays are not the same. Therefore, it is necessary to rebuild a clear concept. Methods : To understand the relationships among 'heaven(天)'-'human(人)' and 'name(名)'-'position(位)', the core concept of the ministerial-fire theory(相火論) of Zhu Dan-Xi(朱丹溪), I examined the relationships between 'heaven(天)' and 'human(人)' in Neo-Confucianism(性理學) of Song(宋) Dynasty and reviewed the notes of Wang Bing(王冰) which were quoted by Zhu Dan-Xi(朱丹溪) to set the concept of monarch-fire(君火) and ministerial-fire(相火). I studied relevant texts. Results : In ministerial-fire theory(相火論) of Zhu Dan-Xi(朱丹溪), monarch-fire(君火) is perceived as being from greed(人欲) that can cause hyperactivity(妄動) of ministerial-fire(相火), whereas ministerial-fire(相火) is perceived as being able to control monarch-fire(君火) by following the orders from heaven. This point of view is different from the past which recognized monarch-fire (君火) as the owner and ministerial-fire(相火) as the servant. Conclusions : Zhu Dan-Xi(朱丹溪) received the ideological impact of Neo-Confucianism, and accepted the notes of Wang Bing, recognized monarch-fire(君火) as 'name(名)' and ministerial-fire(相火) as 'position(位)', so he voiced the ministerial-fire theory(相火論) that perceived monarch-fire(君火) as fire(火) of the five processes(五行) of human body that came from greed, ministerial-fire(相火) as being in a position to hear the order from the 'heaven(天)' to control monarch-fire(君火). But the concept of ministerial-fire(相火) which he set connoted a confusing meaning of 'nature(性)' and 'way(道)' of Neo-Confucianism. In the later process to solve the problem, life-gate theory(命門學說) was raised, and many researchers had tried to remove the meaning of hyperactivity from the ministerial-fire(相火).

Study on Horizontal and Vertical Temperature Analysis of Cable Fire in Common Duct using Room Corner Experiment (룸코너 실험을 이용한 공동구 케이블 화재 시 수평·수직 방향 온도 분석에 관한 연구)

  • JaeYeop Kim;SeHong Min
    • Journal of the Society of Disaster Information
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    • v.19 no.3
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    • pp.634-643
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    • 2023
  • Purpose: Underground common duct fires are steadily occurring, and the proportion of property damage is particularly large among property and human casualties caused by fires. Especially, cable fires that occur in common areas can spread vertically quickly and pose a great risk. This paper aims to scientifically analyze the nature of the fire by reproducing the fire through experiments. Method: To analyze the characteristics of cable fires in underground common duct, heat release rate and temperature changes were measured through Room-corner (ISO 9705) test, and the vertical and horizontal propagation of cable fires was quantitatively compared and analyzed. Result: The Room Corner Test (ISO 9705) was used to compare the temperature changes at each data logger point. The results showed that the time it took for the fire to reach the ignition temperature in the horizontal and vertical directions from the center point of the first-tier cable was 589 seconds and 536 seconds, respectively, which means that the vertical fire propagation is 53 seconds faster than the horizontal propagation. This proves that the vertical propagation of fire is relatively faster than the horizontal propagation. The horizontal propagation speed of the fire was also compared for each floor cable tray. The results showed that the third-tier cable propagated at 3.4 times the speed of the second-tier cable, and the second-tier cable propagated at 1.5 times the speed of the first-tier cable. This means that the higher the cable is located, the faster the fire spreads and the larger the fire becomes. Conclusion: This study identified the risks of cable fires and analyzed the risks of vertical fire propagation during cable fires based on the results of the Room Corner Test. Studies to prevent the spread of fire and fire response policies to prevent vertical fire propagation are required. The results of this study are expected to be used to assess the fire risk of common areas and other fires.

Job Satisfaction Improvement Ways of Fire Official - With a Focus on First-aid Staff - (소방공무원의 직무만족도 향상방안 - 구급대원을 중심으로 -)

  • Kong, Ha-Sung;Lee, Woo-Seoung;Woo, Seong-Cheon
    • Fire Science and Engineering
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    • v.21 no.1 s.65
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    • pp.19-28
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    • 2007
  • The result of survey on job satisfaction of first-aid staff found that degree of work-related stress of 119 first-aid staff got total average 2.54 point (SD.44) out of 4. The degree of fatigue that first-aid staff feel got 2.09 point (SD.49) out of 4. The degree of job satisfaction of 119 first-aid staff got 2.71 point out of 5. This study suggests increasing of new hire, continuous education through teaching before employment, studying abroad, and so on, expansion and modernization of first-aid equipment, introduction and management of OAT institution for improvement of job satisfaction of first-aid staff.

An Evaluation Model for Fire Performance (사격효과측정 모델연구)

  • Han, Kyu-Chill
    • Journal of the military operations research society of Korea
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    • v.3 no.1
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    • pp.97-107
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    • 1977
  • This report examines several models, such as random or area bombardment, salvo fire and pattern fire, for the computation of target coverage when multiple rounds are fired at a target. Fractional kill of a fragment sensitive target by a fragmenting projectile as a function of the number of rounds fired is compared for two salvo fire models. The first is a standard salvo fire model in which N rounds are fired at the same aim point, in the second model single kill probability is computed for a fragment sensitive target and then fractional kill from the firing of N rounds is computed according to the assumption that the effects of each round are independent. Because the method of solution becomes very laborious for large patterns, this report gives a method only for the case of evaluating the effectiveness of stick and trianglar pattern fire. The need for the sophisticated and complicated target coverage models is demonstrated by the results of computations performed in this report.

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Analysis on Shielding Effectiveness of Electromagnetic Wave in Fire Pipes (물이 채워진 소화 배관의 전파 차폐도 해석)

  • Kim, Yoon-Jeung
    • Fire Science and Engineering
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    • v.30 no.4
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    • pp.94-102
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    • 2016
  • When establishing shielding facilities for EMP protection, WBC effect is used to protect fire pipes and honeycomb cells are inserted into the fire pipes to improve the shielding effectiveness. At this point, the smaller unit cell of honeycombs becomes, the more likely it interrupts the flow of water, which ends up clogging the fire pipes with sediment. To prevent this phenomenon, I would suggest a design method due to the pilarization loss of water molecules that contributes to increasing the size of honeycomb cells and remaining thin-walled sufficient for required shielding effectiveness.

A Reliability Analysis on FDS Pyrolysis Model through Comparing the Room-Corner (ISO 9705) Test (룸 코너 콘 칼로리미터 시험(ISO 9705)과 비교를 통한 FDS 열분해 모델의 신뢰성 분석)

  • Yang, Sung-Jin;Lee, Chang-Deok;Oh, Ji-Eun;Kang, Chan-Yong;Kim, Hag-Beom;Lee, Duck-Hee
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.585-593
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    • 2011
  • Actual fire test under a laboratory and fire simulation by using computer are considered into main methodology in order to estimate and predict fire size of railway train. Even if practical fire size could be obtained from the full-model railway car test such as a large scale cone-calorimeter test, it is not always possible and realistic due to that expensive cost and attendant dangers could in no way be negligible. In this point of view, fire simulation analysis method based on the computational fluid dynamics could be proposed as an alternative and it seems to be also efficient and reasonable. However, simulation results have to be verified and validated in accordance with the proper procedure including comparing analysis with the actual fire test. In this paper, fire load and growth aspect was investigated through the room corner test (ISO 9705) for the mock-up model of the actual railway car. Then, it was compared with the output data derived from the simulation by using Pyrolysis Model of the FDS (Fire Dynamics Simulator, by NIST) for the exact same domain and condition corresponding with pre-performed room-corner test. This preliminary verified and validated fire modeling method could enhance the reliability of output data derived from the fire simulation under the similar domain and condition.

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