• Journal of Korean Association for Spatial Structures
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• 제23권2호
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• pp.19-28
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• 2023

Timber structures are susceptible to moisture, contamination, and pest infestation, which can compromise their integrity and pose a significant fire hazard. Despite these drawbacks, timber's lightweight properties, eco-friendliness, and alignment with current architectural trends emphasizing sustainability make it an attractive option for construction. Moreover, timber structures offer economic benefits and provide a natural aesthetic that regulates building temperature and humidity. In recent years, timber domes have gained popularity due to their high recyclability, lightness, and improved fire resistance. Researchers are exploring hybrid timber and steel domes to enhance stability and rigidity. However, shallow dome structures still face challenges related to structural instability. This study investigates stability problems associated with timber domes, the behavior of timber and steel hybrid domes, and the impact of timber member positioning on dome stability and critical load levels. The paper analyzes unstable buckling in single-layer lattice domes using an incremental analysis method. The critical buckling load of the domes is examined based on the arrangement of timber members in the inclined and horizontal directions. The analysis shows that nodal snapping is observed in the case of a concentrated load, whereas snap-back is also observed in the case of a uniform load. Furthermore, the use of inclined timber and horizontal steel members in the lattice dome design provides adequate stability.

• Journal of the Korean Institute of Gas
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• 제27권4호
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• pp.1-11
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• 2023

The size of the OLED material market is expected to grow from $1.1 billion in 2019 to $2.3 billion in 2023, with an average annual sustainable growth of more than 19%. Among the facilities mainly used by OLED material manufacturers, accidents such as fire, explosion, and leakage frequently occur when using filtration equipment, so it is necessary to improve the risk when using filtration equipment. In this study, it was divided into four main processes, namely, assembly and disassembly process, filtration process, wet cake recovery process, and washing process in order to derive the risks associated with the use of filtration equipment. Hazard factors were derived by conducting accident case investigations, preliminary interviews, and surveys. For the analysis of questionnaire results, statistical analysis such as frequency analysis and Pearson chi-square test analysis was performed using SPSS 21, and risk improvement measures were suggested using the analyzed results. It is expected that this study will serve as a basis for dealing with safety and risk factors that may occur as the size of the OLED market expands.

• Journal of the Korean Wood Science and Technology
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• 제44권5호
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• pp.639-654
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• 2016

This study building materials by relates to human hazard assessment in accordance with the combustion gas SEM, the flame-retardant foam FTIR and cone calorimeter to configure the Forest products of MDF and preservative treated Lauan two kinds of Retardant styrofoam, Styrofoam, Urethane foam and gypsum board four kinds of plastics material by the combustion gas were each analyzed. MDF was burned to the structure of the wood and the glue evenly mixed combustion area preservative treated Lauan, kept constant even in the form of high heat to penetrate deep into the wood flame retardant agents. Retardant styrofoam is due to feed my Dropped dissolved inorganic flame retardant without the fire-stick and confirmed that the weak form of gypsum board, but keep the column. In MDF ammonia ($NH_3$), lethal concentration (750 ppm) compared to 795 ppm, preservative treated Lauan is carbon dioxide ($CO_2$) that was greater than 2.5 times the lethal concentration (100,000 ppm) to 256,965 ppm, the lethal concentration (500 ppm) of hydrogen chloride (HCl). The Urethane greater than 697 ppm, 434 ppm also greatly exceeding the nitrogen dioxide ($NO_2$) lethal concentration (250 ppm) in Retardant styrofoam and 398 ppm was released. It is confirmed that the human body is extremely harmful gas emitted from most of the materials to be utilized as basic data for evaluating the hazard-specific human future building material.

• Journal of Korean Tunnelling and Underground Space Association
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• 제24권6호
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• pp.659-677
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• 2022

Hydrogen is emerging as a next-generation energy source and development and supply of FCEV (hydrogen fuel cell electric vehicle) is expected to occur rapidly. Accordingly, measures to respond to hydrogen car accidents are required and researches on the safety of hydrogen cars are being actively conducted. In this study, In this study, we developed a hydrogen car accident scenarios suitable for domestic conditions for the safety evaluation of hydrogen car in road tunnels through analysis of existing experiments and research data and analyzed and presented the hazard distance according to the accident results of the hydrogen car accident scenarios. The accident results according to the hydrogen car accident scenario were classified into minor accidents, general fires, jet flames and explosions. The probability of occurrence of each accident results are predicted to be 93.06%, 1.83%, 2.25%, and 2.31%. In the case of applying the hydrogen tank specifications of FCEV developed in Korea, the hazard distance for explosion pressure (based on 16.5 kPa) is about 17.6 m, about 6 m for jet fire, up to 35 m for fireball in road tunnel with a standard cross section (72 m²).

• Geomechanics and Engineering
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• 제9권4호
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• pp.447-464
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• 2015

Millions of scrap tires are discarded annually in Turkey. The bulk of which are currently landfilled or stockpiled. These tires consume valuable landfill space or if improperly disposed, create a fire hazard and provide a prolific breeding ground for rats and mosquitoes. Used tires pose both a serious public and environmental health problem which means that economically feasible alternatives for scrap tire disposal must be found. Some of the current uses of scrap tires are tire-derived fuel, creating barrier reefs and as an asphalt additive in the form of crumb rubber. However, there is a much need for the development of additional uses for scrap tires. One development the creation of shreds from scrap tires that are coarse grained, free draining and have a low compacted density thus offering significant advantages for use as lightweight subgrade fill and backfill material. This paper reports a comprehensive laboratory study that was performed to evaluate the use of a shredded tire-sand mixture as a backfill material in trench conditions. A steel frame test tank with glass walls was created to replicate a classical trench section in field conditions. The results of the test demonstrated that shredded tires mixed with sand have a definite potential to be effectively used as backfill material for buried pipe installations.

• Journal of the Korean Society of Safety
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• 제21권3호
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• pp.45-52
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• 2006

The AITs(autoignition temperatures) describe the minimum temperature to which a substance must be heated, without the application of a flame or spark, which will cause that substance to ignite. The AITs are often used as a factor in determining the upper temperature limit for processing operations and conditions for handling, storage and transportation, and in determining potential fire hazard from accidental contact with hot surfaces. The measurement AITs are dependent upon many factors, namely initial temperature, pressure, volume, fuel/air stoichiometry, catalyst material, concentration of vapor, time lag. Therefore, the AITs reported by different ignition conditions are sometimes significantly different. This study measured the AITs of benzene, toluene and xylene isomers from time lag using AS1M E659-78 apparatus. The experimental ignition delay times were a good agreement with the calculated ignition delay times by the proposed equations wtih a few A.A.D.(average absolute deviation). Also The experimental AITs of benzene, toluene, o-xylene, m-xylene and p-xylene were $583^{\circ}C,\;547^{\circ}C,\;480^{\circ}C,\;587^{\circ}C,\;and\;557^{\circ}C$, respectively.

• Journal of the Korean Society of Safety
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• 제29권6호
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• pp.76-80
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• 2014

The flash point is one of the most important physical properties used to determine the fire hazard of flammable liquid mixture and defined as the lowest temperature at which a liquid produces sufficient vapor to form a combustible mixture with air. The main purpose of this paper is to measure and predict the flash point of binary flammable miscible mixtures. The flash points for n-hexanol+n-butyric acid and n-butanol+propionic acid, were measured by using Seta-flash closed cup method. The experimentally derived data were correlated with the binary interaction parameters of the van Laar and NRTL equations through the optimization method. The flash points estimated by these correlations were compared with those calculated by the method based on Raoult's law. The optimization method were found to be better than the method based on the Raoult's law.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2011년도 정기 학술발표대회
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• pp.65-65
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• 2011

도시의 확대와 산림의 개발을 통해 산불은 산지의 피해뿐만 아니라, 인접지에도 피해를 입히고 있다. 이는 일반적인 사례가 되어, 이에 대한 연구는 반드시 필요하다고 할 수 있다. 따라서, 본 연구에서는 경상북도의 울진군, 봉화군, 경주시를 대상으로 산림에 인접한 시설물의 빈도와 거리를 분석하여, 산불 발생 시 대피 및 진화 기준을 제시하고자 하였다. 조사 결과, 도시형으로 선정한 경주시가 전체 시설빈도가 가장 높았으며, 산악형으로 분류한 봉화군이 가장 빈도가 낮았다. 가옥의 빈도가 가장 높은 것으로 조사되었으며, 봉화군이 축사의 빈도가 특히 높은 것으로 조사되었다. 산림인접시설물의 산림과의 평균거리분석결과 산악형의 시설물의 평균 산림 인접 거리가 가장 가까우며, 도시형인 경주시의 인접거리가 가장 먼 것으로 조사되었다. 특히, 산악형(봉화 군)은 인접 시설의 산림과의 평균 거리가 100m이내인 것으로 조사되었으며, 산불 발생시 큰 피해가 예상되는 가옥, 의료/복지시설, 주유소, 축사 등 전 시설물의 산림인접 100m 이내 비율도 가장 높은 것으로 조사되었다. 따라서, 산불 발생 시 인접지의 피해가능성이 높은 산림 이격 거리를 100m 이내로 가정할 경우, 봉화군의 경우 산불발생 시 피해가 클 것으로 예상된다. 이러한 연구를 보다 확대하여 향후 산불 발생에 대비한 지역단위 진화와 대피교범과 기준 제작으로 발전시키며, 인접지역 시설물에 대한 산림 위험 시설에 대한 정책수립의 근거로 삼아야 할 것으로 사료된다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2011년도 정기 학술발표대회
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• pp.186-186
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• 2011

고령화사회의 도래는 노인의 신체적 정신적 특성과 더불어 장기적인 보살핌과 보호에 대한 요구를 증대시키고 있다. 노인을 입소시켜 급식과 요양서비스를 제공해주는 노인복지시설은 점차 그 시설수가 증가할 것으로 예상되며 재난상황에 대비한 시설의 설계, 운영, 관리, 유지단계에서 화재방지대책에 대한 연구가 필요하다고 본다. 본 연구에서는 노인복지시설의 실태조사를 통해 양로시설에서는 입지유형과 시설규모별 특징을 분석하고, 노인요양시설에서는 시설의 설계방식과 운영방식에 따른 재난상황 발생시 문제점을 분석하였다. 중점 조사항목은 화재발생시 대피장소 확보, 대피시설 및 장비 유무, 인력배치 기준 준수 등 이며 각 시설별 도출한 취약점을 바탕으로 법 제도적 측면에서 개선방안을 제시하였다. 개선이 필요한 항목은 크게 3분류로, 첫째, 설계 및 건축 단계는 노인복지시설 건축허가 기준 재정립, 피난계단, 피난공간 등 기준 보완을 위해 건축 허가시 화재안전성 검토 등이 필요하다. 둘째, 운영 및 유지 단계는 피난 방화(防火)시설 관리 개선, 시설운영자의 책임안전관리, 소방시설 기능유지 강화 등이 필요하다. 셋째, 대응 및 경감 단계는 방재관련 운영관리매뉴얼, 장비 등의 정비 및 보완, 현장대응 및 전문능력 향상, 화재상황전파 시스템 개발 등이 필요할 것으로 분석되었다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제26권8호
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• pp.102-106
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• 2012

This paper was carried out to survey fire hazard and improvement at the drain pump in air-conditioners. Based on the results of analysis, the proposal of electrical accidents prevention and a construction improvement are as follows. A power connection of the drain pump has two types, an electrical outlet type and direct connection type at control board of air-conditioner. The electrical outlet types need a bulletin sign or education as malfunction of the drain pump include an additional accidents, current leakage and overflowing with water on the floor from breaker trip by exterior cause and breaker off by mistake of worker. On the other hand, the direct connection types prevent a power interruption as exterior cause, but it has some trouble, cut of ground cable and without protection device. Usually it doesn't work by electrician when air-conditioner and the drain pump power work. Therefore an education or countermeasures are recommended for not electrician. Generally malfunction of the drain pump causes accumulated materials into the tank. Even though the accumulated materials lead to an overheating and burning as failure of detector occur an idling, periodic inspection of the air-conditioner filter and the drain pump tank prevent the trouble.