• Title/Summary/Keyword: Fire-heat pattern

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A Study on the Electrical-Fire Analysis and Firing Characteristics of Power Cord by Thermal Stress (열적 피로에 의한 전원코드의 발화 특성과 전기화재 분석에 관한 연구)

  • 최충석;송길목;김향곤;김동욱;김동우
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2003.04a
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    • pp.164-170
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    • 2003
  • In this paper, we studied on the firing characteristics and electrical fire analysis of power cord deteriorated by thermal stress. The cross section of PVC insulating cord deteriorated by indirect flame decreased through heat convection. PVC insulating cord deteriorated by direct flame was bumpy shape. The exothermic peak of normal cord was shown at ($526.7^{\circ}C$), but the peaks or on(heat treatment temperature) ($150^{\circ}C$) cord was shown at ($299.6^{\circ}C$) and [$502.2^{\circ}C$]. The exothermic peaks according to high temperature were similar to those of amorphous carbon. In the FT-IR analysis, the absorption peak of normal cord indicated double bond of oxygen and carbon in benzene ring at 1720.0$cm^{1}$. As the HTT was high, the height of characteristic peak decreased and the peak of carbonyl group was shown at about 1625.7$cm^{-1}$. The characteristic peak of single bond(O-H) was shown at about 3479.2$cm^{-1}$. In case of the internal part of wire covering deteriorated by over current, the characteristic peak were shown at about 3417.3$cm^{-1}$ and 1600.2$cm^{-1}$. The above results show that we can distinguish the differences according to the fire pattern through the internalㆍexternal analysis of wire covering deteriorated by heat.

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A Study on the Damaged Pattern of Dryvit by External Flame (외부화염에 의한 드라이비트의 소손패턴 연구)

  • Park, Young Ju;Hong, Yi Pyo;Lee, Hae Pyeong
    • Journal of the Korean Society of Safety
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    • v.30 no.6
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    • pp.40-47
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    • 2015
  • In this study, temperature characteristics and fire damage form were analyzed to investigate flame spreading form and fire probability from ignition sources subject to drivit component materials which is finishing material in architecture. Ignition sources were limited to a gas torch and exterior panel board fire, and the size of the sample was manufacture in 30 cm length ${\times}$ 50 cm height ${\times}$ 5cm thickness size. Marble (inner wall) + 3 mm drivit (outer wall), marble (inner wall) + 4 mm plaster stone (outer wall), sandwich panel + 3 mm driver bit (outer wall), sandwich panel + 3 mm driver bit + insulation (outer wall), and gypsum board (inner wall) + 3 mm drivit (outer wall) were prepared for the sample. As result of the research for temperature characteristics, large temperature difference by each material was shown in $218^{\circ}C{\sim}995^{\circ}C$ at 30 seconds and $501^{\circ}C{\sim}1078^{\circ}C$ at 300 seconds. Especially when the inner wall was a plaster board, lowest temperature of $501^{\circ}C$ was shown at 300 seconds and marble inner wall showed the following lowest temperature of $900^{\circ}C$. Temperature rising over $1000^{\circ}C$ was shown in other materials. Regarding fire damage form, drivit or gypsum board outer wall parts exposed to fire showed combustion and carbonization to show calcination(breaking phenomenon) and influence of heat exposure was higher as calcination became more severe.

Analysis of Fire Suppression Efficiency for Intermittent Water Spray Pattern by Fire Dynamics Simulator (FDS를 이용한 교번식 미분무방식의 소화 성능 분석)

  • Jee, Moon-Hak;Lee, Byung-Kon
    • Fire Science and Engineering
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    • v.22 no.3
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    • pp.216-220
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    • 2008
  • Water mist fire suppression system utilizes the fire suppression features such as cooling of fire source, dilution of ambient oxygen, and shielding of radiation heat with the evaporation of microscopic water droplets. The momentum of water mist is relatively lower than that of larger water droplet and the infiltration of water mist to the fire source is not effective. Contribution of evaporated water vapor is liable to decline to limited portion of fire source due to its light weight and sparse density. On the other hand, the cycling water mist pattern is expected to improve the penetration force of water mist as well as the air expelling capability with the stratified spray characteristics. At this paper, we present the analyzed fire suppression capability of intermittent water spray pattern by use of FDS which is computational fire dynamics fire model. We expect this analysis can support the basic concept to the development of the prototype of water mist nozzle.

The Study on Pattern Differentiations of Primary Headache in Korean Medicine according to the International Classification of Headache Disorders (ICHD 분류에 따른 원발 두통의 한의학적 변증 연구)

  • Lee, Jeong So;Park, Mi Sun;Kim, Yeong Mok
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.31 no.4
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    • pp.201-212
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    • 2017
  • This study draws pattern differentiations of headache disorders on the ground of modern clinical applications and Korean medical literature. Categorization and symptoms of headache disorders are based on International Classification of Headache Disorders 3rd edition(beta version). And clinical papers are searched in China Academic Journals(CAJ) of China National Knowledge Infrastructure(CNKI). In the aspect of eight principle pattern identification, primary headache occurs due to lots of yang qi and has more inner pattern rather than exterior pattern, heat pattern rather than cold pattern, excess pattern rather than deficiency pattern. And primary headache is related with liver in the aspect of visceral pattern identification and blood stasis, wind and phlegm are relevant mechanisms. Migraine without aura is associated with ascendant hyperactivity of liver yang, phlegm turbidity, sunken spleen qi, wind-heat, blood deficiency or yin deficiency. Migraine with aura is mainly related with wind and it's major mechanisms are ascendant hyperactivity of liver yang, liver fire, yin deficiency of liver and kidney, blood deficiency or liver depression and qi stagnation. High repetition rate of tension-type headache can be identified as heat pattern or excess pattern. And trigeminal autonomic cephalalgias can also be accepted as heat pattern or excess pattern when the occurrence frequency is high and is relevant to combined pattern with excess pattern of external contraction and deficiency pattern of internal damage based on facial symptoms by external contraction and nervous and anxious status by liver deficiency. This study can be expected to be Korean medical basis of clinical practice guidelines on headache by proposing pattern identifications corresponding to the western classifications of headache disorders.

Characteristics of Fire-induced Thermal-Flowfields in an Underground Utility Tunnel with Ventilation (화재 발생시 환기방식에 따른 지하공동구내 열유동 특성 연구)

  • Kim, Hong-Sik;Hwang, In-Ju;Kim, Yun-Je
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1845-1850
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    • 2003
  • The underground utility tunnels are important facility as a mainstay of country because of communication developments. The communication and electrical duct banks as well as various utility lines for urban life are installed in the underground utility tunnel systems. If a fire breaks out in this life-line tunnel, the function of the city will be discontinued and the huge damages are occurred. In order to improve the safety of life-line tunnel systems and the fire detection, the behaviors of the fire-induced smoke flow and temperature distribution are investigated. In this study we assumed that the fire is occurred at the contact or connection points of cable. Numerical calculations are carried out using different velocity of ventilation in utility tunnel. The fire source is modeled as a volumetric heat source. Three-dimensional flow and thermal characteristics in the underground tunnel are solved by means of FVM (Finite Volume Method) using SIMPLE algorithm and standard ${\kappa}-{\varepsilon}$ model for Reynolds stress terms. The numerical results of the fire-induced flow characteristics in an underground utility tunnel with different velocity of ventilation are graphically prepared and discussed.

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A Case of Recurrent Aphthous Stomatitis Improved by Korean Medical Treatments - Focus on the effectiveness of Chungyeoldodam-tanggagam and Dangguisoo-san Plus Yuhyangjeongtong-sangagam (한방 치료로 호전된 재발성 아프타성 구내염 치험 1례 - 청열도담탕가감(淸熱導痰湯加減)과 당귀수산합유향정통산가감(當歸鬚散合乳香定痛散加減) 사용효과를 중점으로)

  • Kim, Tae-Jun;Kim, Yong-Min;Kim, Hee-Taek
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.33 no.2
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    • pp.140-155
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    • 2020
  • Objectives : The purpose of this study is to report the effectiveness of korean medical treatments on recurrent aphthous stomatitis(RAS) diagnosed as excess pattern(實證) based on symptoms of damum(痰飮), blood stasis(瘀血) and fire-heat(火熱). Methods : We treated a 61-year-old male patient who has RAS by korean medicine, pharmacopuncture and acupuncture treatment. These treatments were performed from 2020.01.22. to 2020.02.29. We have confirmed the improvement of ulcer lesions and pain. We recorded images that include change of symptoms. Results : After the treatments were done, the scores of numeric rating scale(NRS), oral health impact profile-14 (OHIP-14), oral assessment guide (OAG) and world health organization oral toxicity scale (WHO OTS) were decreased. The NRS score was decreased from 7 to 1. The OHIP-14 score was decreased from 30 to 14. The OAG score was decreased from 17 to 9. The WHO OTS score was decreased from 2 to 1. And ulcer lesions were clearly decreased. Conclusions : According to the result, korean medical treatments such as korean medicine, pharmacopuncture and acupuncture treatment, that are targeted at excess pattern(實證) caused by damum(痰飮), blood stasis(瘀血) and fire-heat(火熱) can be effective for the treatment of RAS.

Development of a Numerical Model for the Rapidly Increasing Heat Release Rate Period During Fires (Logistic function Curve, Inversed Logistic Function Curve) (화재시 열방출 급상승 구간의 수치모형 개발에 관한 연구 (로지스틱 함수 및 역함수 곡선))

  • Kim, Jong-Hee;Song, Jun-Ho;Kim, Gun-Woo;Kweon, Oh-Sang;Yoon, Myong-O
    • Fire Science and Engineering
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    • v.33 no.6
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    • pp.20-27
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    • 2019
  • In this study, a new function with higher accuracy for fire heat release rate prediction was developed. The 'αt2' curve, which is the major exponential function currently used for fire engineering calculations, must be improved to minimize the prediction gap that causes fire system engineering inefficiency and lower cost-effectiveness. The newly developed prediction function was designed to cover the initial fire stage that features rapid growth based on logistic function theory, which has a more logical background and graphical similarity compared to conventional exponential function methods for 'αt2'. The new function developed in this study showed apparently higher prediction accuracy over wider range of fire growth durations. With the progress of fire growth pattern studies, the results presented herein will contribute towards more effective fire protection engineering.

The correlation between average temperature & precipitation and Pattern Identification of the patients with stroke (중풍환자의 변증(辨證)과 기온 및 강수여부와의 상관성에 관한 연구)

  • Ma, Mi-Jin;Kim, Bo-Ram;Kim, Mi-Kyung;Choi, Dong-Jun;Han, Chang-Ho;Jung, Seung-Hyun;Shin, Gil-Jo;Lee, Won-Chul
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.9 no.1
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    • pp.8-13
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    • 2008
  • Objectives : This study was to investigated the correlation between average temperature & precipitation and pattern identification of the patients with stroke. Methods : 115 stroke patients within 30days of onset were registered during the study period. Pattern identification of stroke was classified into Fire and heat, Turbid phlegm and others. We took the mean of average temperature according to pattern identification and analyzed pattern identification into two groups according to climatological normal of average temperature in Seoul. We also analyzed pattern identification into two groups according to existence of precipitation. Results : Heat and fire, and other type of pattern identification had high frequency when average temperature was higher than 12.2℃. And there was no correlation between precipitation and pattern identification of stroke.

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Study on the Relation between Each Pattern Identification and Blood Lipid Level in Stroke Patients (중풍(中風)환자의 5개 변증(辨證)과 혈중지질의 상관관계 연구)

  • Shin, Hyun-Su;Kang, Byoung-Kab;Ahn, Jung-Jo;Yoo, Ho-Ryong;Kim, Yoon-Sik;Seol, In-Chan;Jo, Hyun-Kyung
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.5
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    • pp.883-891
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    • 2010
  • The purpose of this study was to investigate the relation between each pattern identification such as Dampness-Phlegm, Fire-Heat, Deficiency of Qi, Deficiency of Yin and Blood Stagnation and blood lipid level in acute stroke patients. This study was done over patients hospitalized in 13 Oriental Medical Hospitals in the period of November 2006 to Jun 2009. Patients had been interviewed by residents and medical specialists who studied standard operation procedures in Fundamental Study for Syndrome of Oriental Medicine for Stroke. Study subjects consisted of group A that was distributed to specified pattern identification by medical specialist and discriminating program, group B that was distributed to specified pattern identification by medical specialist or discriminating program, and the control group that wasn't distributed to specified pattern identification by medical specialist and discriminating program. For the purpose of obtaining suitable result, we analyzed blood lipid level of each group by univariate analysis. In this study, there was not statistically significant relation between most of each pattern identification and blood lipid level except relation between Fire-Heat pattern group B and decreasing HDL cholesterol. Based on these results, it is suggested that Dampness-Phlegm would not be the independent predictors of hyperlipidemia unlike other studies that were presented in. More prospective studies between Fire-Heat and decreasing HDL cholesterol are to be done with more clinical data.

A Study on the Heat Release Characteristics of Fire Load for Performance Based Design of Multiplexes: A Focus on the Heat Release Rate and Fire Spread Rate of Cinema Seats (복합영상관의 성능위주설계를 위한 가연물의 연소발열특성 연구: 객석의자의 열발생률 및 연소확산속도를 중심으로)

  • Nam, Dong-Gun;Jang, Hyo-Yeon;Hwang, Cheol-Hong;Lim, Ohk-Kun
    • Fire Science and Engineering
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    • v.34 no.1
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    • pp.11-17
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    • 2020
  • As performance-based design (PBD) has a direct impact on evacuation safety assessments, designing fire scenarios based on real fire tests is essential. To improve the reliability of the PBD for fire safety in multiplexes, information on fire behavior, such as heat release rate (HRR) and fire spread rate, are provided in this study by conducting a standard fabric flammability test. To this end, several chairs were arranged in a pattern that resembled a theater-style seating. The peak HRR and heating value per unit mass for each chair ranged from 415 kW to 988 kW and 15.2 MJ/kg to 23.8 MJ/kg, respectively. The heating values per unit mass of the new and old chairs were 23.6 MJ/kg and 16.7 MJ/kg, respectively. As the quantity of plastic and cushioning materials in the new chairs was more than that of the old ones, the new chairs were more vulnerable to fire hazards. Furthermore, when the chairs were arranged in a line, the fire spread rate was observed to be 0.39-0.42 m/min, regardless of the ignition location. Finally, a fire growth curve showing the peak HRR and fire spread rate was also demonstrated.