• Title/Summary/Keyword: fire behavior

Search Result 594, Processing Time 0.023 seconds

A Study on Thermal Characteristics of Biodiesel (바이오디젤의 열적특성에 관한 연구)

  • Bae, Byong-Mok;Lim, Woo-Sub;SaKong, Seong-Ho;Mok, Yun-Soo;Choi, Jae-Wook
    • Journal of the Korean Society of Safety
    • /
    • v.25 no.6
    • /
    • pp.92-97
    • /
    • 2010
  • A study is conducted on thermal characteristics of biodiesel which is already being produced in many countries because of its stable supply of energy in non oil-producing countries and economical benefits against increasing oil price, and environment conservation. So biodiesel has been used as important energy source in the fuel fields and a mount of production has increased year by year. Therefore, it is very important to find out the thermal characteristics of biodiesel for ignition temperature, maximum pressure and thermal behavior. The purpose of this study is to compare on thermal characteristics of biodiesel, petroleum diesel and those mixtures. Also, the main study was performed by flash point testers and modified closed type of pressure vessel test (MCPVT). Based on the data of flash point and MCPVT, the ignition temperature and the maximum pressure of biodiesel was $182^{\circ}C$ and 40.1bar, and petroleum diesel was $54^{\circ}C$ and 29.8bar.

A Study on the Chemical Warfare Agents Dispersion Modelling in a Naturally Ventilated Indoor System (자연환기상태 실내공간에서의 화학작용제 확산 모델링 연구)

  • Kye, Young-Sik;Chung, Woo-Young;Kim, Yong-Joon
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.11 no.4
    • /
    • pp.133-140
    • /
    • 2008
  • The purpose of this study is to provide response methods to minimize the damage from chemical terrorism in a naturally ventilated indoor system using several types of dispersion simulations. Three chemical warfare agents such as sarin(GB), phosgene and chlorine gas which have high potential to be used in terror or to be involved with accidents were selected in this simulation. Fire dynamic simulation based on Large Eddy Simulation which is effective because of less computational effort and detailed expression of the dispersion flow was adopted to describe the dispersion behavior of these agents. When the vent speed is 0.005m/s, the heights of 0.1 agent mass fraction are 0.9m for sarin, 1.0m for phosgene and 1.1m for chlorine gas, and the maximum mass fraction are 0.27 for all three agents. However, when the vent speed is increased to 0.05m/s, the heights of 0.1 agent mass fraction become 1.6m for all three agents and maximum mass fraction inside the room increase to 0.70 for sarin, 0.58 for phosgene and 0.53 for chlorine gas. It is shown that molecular weight of the agents has an important role for dispersion, and it is important to install ventilation system with height less than 1.6m to minimize the damage from chemical toxicity.

EFFECT OF TOP END CONDITION OF FUEL BED CONTAINER ON DOWNWARD SMOLDER SPREAD

  • Sato, Kenji;Sakai, Yasuhiro
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
    • /
    • 1997.11a
    • /
    • pp.146-153
    • /
    • 1997
  • An experimental study was performed of natural-convection downward smolder spread across a sawdust bed peripherally enclosed with an insulating container, to examine the effect of the open- ing condition at the top end on downward smolder spread. Experiments were conducted by using relatively coarse sawdust and 25-cm-long cylindrical container The variations of temperature profiles along the bed axis with time were determined far different opening conditions and were com-pared with those in smolder spread from open top to open bottom. It was shown that the smolder zone initiated from open top toward closed bottom penetrates the bed with keeping high peak temperature like the case of open top to open bottom spread, although mean spread rate is smaller. This indicates that the downward smolder zone can be sustained stably if sufficient air or oxygen Is supplied from the back of it by natural convection even if upward draft entering from the bottom of the bed is absent. When the top end was partially closed by mounting a cover after stable smolder spread had begun from open top toward open bottom, the temperature at the peak decreased more than 200 K and the smolder zone became to spread with thickening residue. In this case, the shape of temperature profiles continuously changed or decayed until end-effect at the open bottom end enhanced the reaction. The temperature at the shrunk peak, free from the end-effect, was almost identical with the temperature at the exothermic oxidative-degradation zone in smolder spread from open top to open bottom. from these results, it can be inferred for natural-convection downward smolder spread that the oxidation reaction of the char is very sensitive to the oxygen supply by natural convection in the space above the smolder zone, and that the top end opening condition strongly alters the completeness of reactions, structure, and behavior of the smolder zone.

  • PDF

Effects of Flow Excitation on the Nitrogen Oxide Emission of a Non-Premixed Flame (유동장 자극이 화염의 질소산화물 배출에 미치는 영향)

  • 이기만
    • Fire Science and Engineering
    • /
    • v.18 no.2
    • /
    • pp.34-40
    • /
    • 2004
  • The effects of external flow excitation with various frequencies and amplitudes on the flame behavior and pollution emission characteristics from a laminar jet flame are experimentally investigated. Measurements of $NO_x$ emission indices ($EINO_x$), performed in vertical lifted flame like turbulent with various exciting amplitude at a constant resonance frequency, have been conducted. It was also conducted to investigate the effects of excited frequency at a constant exciting amplitude on $NO_x$ emissions with a various frequency ranged 0 Hz to 2 KHz. From the vertical lifted turbulent flame of the excited jet with resonance frequency by strong excitation was shown that the dependence of $NO_x$ emission could be categorized into three groups Group I of long flame length with high disturbances yielding high $NO_x$ emission, Group II of intermediate flame length and relative narrow flame volume with low disturbance yielding low $NO_x$ emission and Group III of long flame length and large flame volume with high time & space disturbances behaviour yielding high $NO_x$ emission.

Survival and Goodness in a Post - apocalyptic Future: Cormac McCarthy's The Road (포스트 - 묵시록 미래의 생존과 선의 실행: 코맥 매카시의 『로드』)

  • Sung, Junghye
    • English & American cultural studies
    • /
    • v.16 no.2
    • /
    • pp.71-88
    • /
    • 2016
  • Cormac McCarthy's The Road depicts a post-apocalyptic future in which the time and reason of catastrophe are not specified, but it can be seen to project the contemporary social and ethical concerns in the dismal setting. In this respect, the journey the man and boy depart for to the South is on one hand a journey to seek a warmer place to support their lives in the literal sense and, on the other hand, a journey to seek 'what a human being is' in the devastated world in a metaphorical sense since they face extremely harsh and tremendously poignant conditions in which their creed as human beings is tested. This paper aims to explore the hazards of the current society that the text criticizes and the morality and ethical values to be preserved and pursued. The second chapter examines how the text describes the contemporary crisis through the dark and coldness of the land and its sterility. The land produces almost nothing as the entire surface was scorched and is now covered with thick ashes. It shows perfectly a destroyed and irrecoverably frozen land. Throughout this desolate and ruined land, the atrocity and violence of the survivors goes beyond the limit. Ravaging strangers and plundering villages are widely spread. These conditions mirror the apparent selfishness and immorality of the recent society. The third chapter analyzes the man's inconsistent or dualistic narrative on the good. He knows what the good is but doesn't allow the boy to demonstrate the good behavior on others. His conflict is rooted in his hope to protect his son from being attacked by others. Therefore it can be interpreted that the meaning and orders of living in this post-apocalyptic period are uncertain and indecisive. The fourth chapter examines the belief the man and the boy clings to. Unlike the man's contradictory decisions, he shows definite firmness to be 'the good' by not eating people and carrying 'the fire.' Until he dies, the man endeavors to protect his son and have him acquire the moral conviction and strength to carry the fire in the world. In conclusion, the text reads the current society critically and highlights the importance of the humanity that must not be discarded throughout the generations.

Role of Interventions in Preventing Unintentional Home Injuries of Older Adults in Korea: A Scoping Review (국내 노인의 가정 내 비의도적 손상예방을 위한 중재의 역할: 주제범위 문헌고찰)

  • Cho, Ok-Hee;Hwang, Kyung-Hye;Kim, Hyekyung
    • Journal of Home Health Care Nursing
    • /
    • v.31 no.1
    • /
    • pp.16-29
    • /
    • 2024
  • Purpose: This scoping review aimed to synthesize the characteristics and effects of interventions designed to prevent unintentional home injuries in older adults in Korea. Methods: The review was conducted following the Joanna Briggs Institute protocol. A literature search was performed for studies published between 2001 and 2022 in the DBPia, RISS, KMBase, and NDSL databases. A total of 1,620 studies were identified, and 27 studies were included in the final analysis. Data were analyzed for characteristics of the literature, intervention-related unintentional injury mechanisms, and safety areas. Results: Most selected studies utilized a quasi-experimental design and targeted elderly women. In terms of injury mechanisms, 21 of 27 studies focused on falls, 2 on fire/disaster, 3 on drugs, and 1 on food. The most common preventive intervention for falls was exercise, and its effectiveness was verified using physical safety variables. Interventions in the fire/disaster, drug, and food domains were all educational, and changes in knowledge, behavior, and attitude were verified. Conclusion: This study confirmed the effectiveness of interventions for preventing unintentional injuries in the homes of community-dwelling older adults. These findings can serve as a foundation for developing and implementing unintentional injury prevention interventions at home for community-dwelling older adults. Multidisciplinary research is needed to address multifaceted safety issues by considering the home environment and injury risk factors.

Change of Statical Behavior and Ultimate Capacity of Steel Cable-stayed Bridges after Cable Failure (케이블 단선 후 강사장교의 구조 및 극한 거동 변화)

  • Kim, Seung-Jun;Choi, Jun-Ho;Won, Deok-Hee;Han, Taek-Hee;Kang, Young-Jong
    • Journal of Korean Society of Steel Construction
    • /
    • v.23 no.6
    • /
    • pp.747-761
    • /
    • 2011
  • This paper presents an investigation on the change in the statical behavior and the ultimate capacity of steel cable-stayed bridges after cable failure. Cable failure can occur due to fire, direct vehicle clash accidents, cable or anchorage fatigue, and so on. Moreover, the cable may be temporarily disconnected during cable replacement work. When cable failure occurs, the load, that was supported by the broken cable is first transferred to another cable. Then the structural state changes due to the interaction between the girder, mast, and cables. Moreover, it can be predicted that the ultimate capacity will decrease after cable failure, because of the loss of the support system. In this study, the analysis method is suggested to find the new equilibrium state after cable failure based on the theory of nonlinear finite element analysis. Moreover, the ultimate analysis method is also suggested to analyze the ultimate behavior of live loads after cable failure. For a more rational analysis, a three-step analysis procedure is suggested and used, which consisted of initial shape analysis, cable failure analysis, and live load analysis. Using this analysis method, an analytical study was performed to investigate the changes in the structural state and ultimate behavior of steel cable-stayed bridges.

Predictive Factors on Blood Donation Intention in Middle Aged Base on the Theory of Planned Behavior : Focused on the Firefighter and Prison Officer (계획된 행위 이론에 근거한 중장년층의 헌혈 의도 영향요인 : 소방직과 교정직 중심으로)

  • Da Jung Lee;Hye-Kyung Lee
    • Journal of the Korean Applied Science and Technology
    • /
    • v.40 no.2
    • /
    • pp.199-209
    • /
    • 2023
  • This study is a descriptive research to identify the factors that influence blood donation intentions of the middle-aged firefighters and prison officer based on Ajzen's (1991) planned behavior theory. The subjects of the study were 223 middle-aged firefighters and prison officer at a fire station and prison located in G City and District B. The Data were analyzed by descriptive statistics and t-test, one-way ANOVA, Pearson's correlation coefficient, Turkey, and multiple regression with the SPSS 21.0 program. There were statistically significant differences in blood donation intention according to the blood donation experience, attempted blood donation within a year, participate plan in blood donation within 3 months. The blood donation intention of middle aged showed significant positive correlations with attitude, subjective norms, and perceived behavioral control towards blood donation. Multiple regression analysis for blood donation intention revealed that the significant predictors were participate plan in blood donation within 3 months, perceived behavior control, subjective norms, attitude towards blood donation, and attempted blood donation within a year. These factors explained 69% of the variance. In order to enhance the middle aged's intention to blood donation, we need a program that can improve middle aged's attitude, subjective norms, perceived behavior control.

Measurement of Flash Point for Binary Mixtures of 2-Butanol, 2,2,4-Trimethylpentane, Methylcyclohexane, and Toluene at 101.3 kPa (2-Butanol, 2,2,4-Trimethylpentane, Methylcyclohexane 그리고 Toluene 이성분 혼합계에 대한 101.3 kPa에서의 인화점 측정)

  • Hwang, In Chan;In, Se Jin
    • Clean Technology
    • /
    • v.26 no.3
    • /
    • pp.161-167
    • /
    • 2020
  • For the design of the prevention and mitigation measures in process industries involving flammable substances, reliable safety data are required. An important property used to estimate the risk of fire and explosion for a flammable liquid is the flash point. Flammability is an important factor to consider when developing safe methods for storing and handling solids and liquids. In this study, the flash point data were measured for the binary systems {2-butanol + 2,2,4-trimethylpentane}, {2-butanol + methylcyclohexane} and {2-butanol + toluene} at 101.3 kPa. Experiments were performed according to the standard test method (ASTM D 3278) using a Stanhope-Seta closed cup flash point tester. A minimum flash point behavior was observed in the binary systems as in the many cases for the hydrocarbon and alcohol mixture that were observed. The measured flash points were compared with the predicted values calculated via the following activity coefficient (GE) models: Wilson, Non-Random Two-Liquid (NRTL), and UNIversal QUAsiChemical (UNIQUAC) models. The predicted data were only adequate for the data determined by the closed-cup test method and may not be appropriate for the data obtained from the open-cup test method because of its deviation from the vapor liquid equilibrium. The predicted results of this work can be used to design safe petrochemical processes, such as the identification of safe storage conditions for non-ideal solutions containing flammable components.

Cognitive behavior intervention for critical incident stress management in fire fighters in Korea (소방공무원의 위기상황 스트레스 관리를 위한 인지행동 개입과 대책)

  • Lee, Eun-Jung;Kim, Jee-Hee
    • Journal of the Korea Convergence Society
    • /
    • v.6 no.2
    • /
    • pp.13-18
    • /
    • 2015
  • The purpose of the study is to investigate the predisposing factors of posttraumatic stress disorder (PTSD) in fire fighters in Korea and to suggest the program development and solution to the critical incident stress management (CISM) in the future. PTSD is characterized by invasion, withdrawal, negative change of cognition and mood, and hypersensitivity. Trauma memory includes explicit memory and implicit memory. The explicit memory is conscious, cognitive, and descriptive and is controlled by hippocampus. The data of explicit memory have inhibitive and narrative language structure. The implicit memory is inconscious, emotional, and remembered by the body. The implicit memory is controlled by amygdala and has inexpressive language structure. The deletion of implicit memory is the key point to trauma treatment. Critical incident stress management (CISM) is the approach for the solution of PTSD. In conclusion, the essential goal of CISM is the psychological cessation of PTSD. This study tried to suggest the education program development of PTSD.