• Fire Science and Engineering
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• v.34 no.2
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• pp.94-96
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• 2020

In November 2013, a case of sustained combustion of a female body was encountered in a Korean farming village. The body was almost completely incinerated from the neck to the knees, and other parts of the body, such as the head, arms, lower legs, and feet, were slightly damaged. The most likely external ignition source was the flame from a matchstick. The elderly woman was found incinerated on the floor of the living room, while other objects in the house were largely undamaged except for having a brown oily or greasy coating. Flammable substances were not detected from the woman's intact pieces of clothing and socks, and her muscular tissues did not contain toxic chemicals. The concentration of carboxyhemoglobin in her peripheral blood was 11% and that of ethyl alcohol in her aqueous humor was below 0.010%. An autopsy failed to determine the exact cause of death because of excessive charring.

• Fire Science and Engineering
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• v.33 no.3
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• pp.9-20
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• 2019

This study was examined fire risk properties of wood specimen for the constructional interiors, especially focusing on the fire performance index (FPI) and the fire growth index (FGI) as heat hazard characteristics. Flame retardants were synthesized using boric acid, boronic acid and tetraethoxyorthosilicate. Heat release characteristics were measured by using a cone calorimeter (ISO 5660-1) and cypress was used. The external heat flux as fire intensity was maintained at 50 kW/㎡. The measured fire performance index (FPI) after burning was increased by 1.6 times for boric acid/silicone (BA/Si) sol, each 1.1 times for isobutylboronic acid/silicone (IBBA/Si) sol and phenylboronic acid/silicone (PBA/Si) sol compared with cypress. Fire risk by the fire performance index was increased BA/Si, IBBA/Si ≈ PBA/Si order. The fire growth index was decreased 94% for the BA/Si and 8% for the IBBA/Si sol, and was increased by 17% for the PBA/Si sol. Fire risk by the fire growth index was increased BA/Si, IBBA/Si, PBA/Si order. Overall fire risk was higher in the order of BA/Si < IBBA/Si < PBA/Si.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.1
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• pp.23-40
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• 1999

The analysis of thiodiglycolic acid in urine has been used as an index of biological exposure to vinyl chloride. Unfortunately thiodiglycolic acid has a strong hydrophilic character, because it has two carboxylic groups, so that it can only be extracted with organic solvent with a great difficulty. Underivatized thiodiglycolic acid tends to tail because of non-specific interaction with the inert support. Therefore, esterification is the obvious first choice for derivatization of thiodiglycolic acid, particularly for gas chromatography. In this study, the focus of interest is to compare two method of esterifications (methylation and silylation). Methylation is to make the methyl ester of thiodiglycolic acid by reaction with diazomethane. Silylation is to make the trimethylsilyl ester of thiodiglycolic acid by reaction with N-trimethylsily-ldiethylamine. The results and conclusions are as the following: 1. The detection limit (sensitivity) of methylated thiodiglycolic acid was $5.00{\mu}g/m{\ell}$ and silylated thiodiglycolic acid was $3.07{\mu}g/m{\ell}$ by gas chromatography with flame ionization detector. 2. The optimal liquid-liquid extraction of thiodiglycolic acid was as following: To each of the tubes, $15m{\ell}$ of urine, concentrated sulfuric acid (pH 1 - 2) and 5 gsodium sulfate were added. The samples was extracted three times with $5m{\ell}$ ethylacetate each time. 3. The methylated thiodiglycolic acid was more stable than silylated thiodiglycolic acid in extractional solvent which contained humidity. 4. The precision (pooled coefficient of variation for 4 days) of the analysis was 0.07324 in methylated thiodiglycolic acid with external standard calibration, and 0.07033 in methylated thiodiglycolic acid with internal standard calibration. 5. The precision (pooled coefficient of variation for 4 days) of the analysis was 0.10914 in silylated thiodiglycolic acid with external standard calibration, and 0.13602 in silylated thiodiglycolic acid with internal standard calibration. From the above results, the analysis of methylated thiodiglycolic acid was more sensitive (limit of detection) than silylated thiodiglycolic acid by gas chromatography. However, the methylated thiodiglycolic acid was stable in the humidity and was separated sharply on chromatogram. Also, analysis of methylated thiodiglycolic acid was more precise (pooled coefficient of variation for 4 days) than silylated thiodiglycolic acid. In conclusion, it is established that the analysis of methylated thiodiglycolic acid is appropriate for biological monitoring of exposure to vinyl chloride.

• Journal of the Korean Society of Safety
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• v.33 no.3
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• pp.15-20
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• 2018

There have been a number of major fatal fire accidents in Korea recently. The number of fires in 2017 were 44,178, which is not only increasing number of fires but also increasing in casualties. Particularly, the fire at Jecheon Sports Center, which suffered many casualties, is expected to have a huge impact. The cause of the fire has not been determined yet, but heat waves on the ceiling have also been pointed out. As such, the copper heating waves, which are used as a preventive measure against damage of pipes due to freezing of pipes, etc., always have a fire hazard. To determine the possibility of a flame-resistant heated fire, a positive electric cable product was used to artificially ignite and analyze the results. In case of a short circuit, the external covering of the positive electric cable is damaged, but not short circuit unless the heating material surrounding the wire is damaged. Due to the characteristics of heating cable for preventing copper waves, the chances of insulation becoming more severe due to moisture and temperature changes are higher than normal wires. If the internal heating system is carbonized by insulating deterioration without damage to the outer coating, it is likely to cause trekking, to form a winding loop in the heating materials, and to cause short circuit in the heated materials. For the positive temperature line, if the middle is shorted, the current continues to flow to the short circuit unless the breaker disconnects. Consequently, a heated fire that does not cut off the power immediately may leave multiple marks or cuts.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.1
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• pp.121-130
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• 1986

Using the sbsorption coefficients and the weighting factors of the gray gas, the total emissivities of C $O_{2}$- $H_{2}$O and C $O_{2}$- $H_{2}$O- transient species-soot gas mixtures can be expressed by the following equation, [a numerical formula] Where, $a_{i}$ and $K_{i}$ represent the weighting factor and the absorption coeffient of i-gray gas respectively; L is the pathlength of the gas. This equation is widely used for the analyses of the radiation heat transfer in the combustors of internal combustion engines and in the furnace of external combustion engines. In this work, a simple calculation model of the weighting factor and the absorption coeffient of the above equation was developed. The weighting factors and the absorption coefficients of combustion products were calculated by applying the model to various kinds of fossil fuels such as coal and heavy oil. Then, the computed total emissivities for each fuel and pathlength were compared with measured and calculated values which have been already published in the literatures. The followings were the results obtained through the comparisons between the calculated emissivites and the published values; the developed model for the calculations of the weighting factor and the absorption coefficient of C $O_{2}$- $H_{2}$O and C $O_{2}$- $H_{2}$O- transient species-soot gas mixtures could be applied over the wide ranges of the temperature and the pathlength; the errors between the total emissivities calculted and the values published were maximum 10%, and average 1%, respectively.

• Fire Science and Engineering
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• v.20 no.1 s.61
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• pp.43-49
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• 2006

In this paper, we are studied on the temperature characteristics and fire progress of an incandescent electric lamp at 220V/100W. In the case of stationary state, the ignition possibility of the incandescent electric lamp due to the heat generation was low because the temperature was measured at $161.9^{\circ}C$ the temperature was increased at $538.1^{\circ}C$ in the airtight chamber, but it does not generated the fire because the oxygen was not exist in the airtight chamber. When the lamp is broken, the filament of lamp was melted in the air. The gas of lamp interior spurted to the weakest part by external flame. Thus, the incandescent electric lamp is high possibility of fire when oxygens from airtight space. Also, it is known that the possibility of ignition is very high if combustion materials(sawdust) exists on surrounding. These experimental results will be utilized for the data in the investigation electrical fire cause.

• Fire Science and Engineering
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• v.33 no.3
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• pp.121-127
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• 2019

This study examined a fire accident caused by a defect in the vehicle ABS module. A large number of vehicles using the same manufacturer's ABS module in recent fire events showed a tendency to combust due to the same faults. As previously stated in the ABS module which shows the electrical breakdown between the power lines supplied to the constant power source by the battery. The electrical breakdown of the ABS module was caused by defects of the ABS module itself that were influenced by of the external flame. These results highlight the need to determine if there is a deficiency of the ABS module in the investigation of the cause of a fire in a vehicle which is produced by the same manufacturer.

• Fire Science and Engineering
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• v.30 no.4
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• pp.88-93
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• 2016

A fire detector installed in wood cultural properties has not have selected the detector type appropriate for the features of cultural properties and the structure of wood fire after the fire in Sungnyemun-Gate since 2008. Applying wooden cultural properties different from the general architecture of the structure and fire characteristics is difficult. Therefore, buildings were classified into four shape types and field survey and wooden architecture structure characteristics to identify the problems of the detectors installed on wooden cultural property buildings. The problems appeared to lack the adaptability to external fire detection sensor selection and missing fire detectors installed in accordance with the place. To solve the problem, the closed and open space of the rooms used a smoke detector, outdoor select flame or fixed temperature linear detector to solve the problem.

• Journal of the Korea Institute of Building Construction
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• v.20 no.4
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• pp.339-345
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• 2020

This study used a real-scale model experiment to reproduce internal fires in residential buildings such as a multi-dwelling unit, in order to prevent damage caused by tens of thousands of fires witnessed each year and to take measures to cope with them. For experimental conditions, different opening sizes were applied to measure and analyze the heating temperature of the exterior wall. Results drawn are as follow : On top of this, the experimental conditions had whether to install shading and put a shading length differently, before measuring and analyzing the heating temperature of the exterior wall. Subsequent results were drawn as shown below. Based on the maximum temperature, the temperature was lowered as much as around 90℃ at 150mm, around 150℃ or over at 300mm and over 175℃ at 450mm. It also turned out that the difference in maximum temperature dropped by around 180℃ or over. This indicated that the shading installation works well in lowering flame temperature generated by fire spread of the exterior wall.

• Architectural research
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• v.24 no.2
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• pp.21-27
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• 2022

For the past decade, South Korea had experienced catastrophic building fires, which resulted in consider-ably high number of casualties. This motivated research to develop fire-safe wall assemblies. In this study Fire Risk Analysis (FRA) is conducted as part of the project designing phase to ensure fire safety of the final product. Traditional approach was to consider fire performance at the end of the designing stage, when PASS/FAIL fire test results are required to be submitted to the Authority Having Jurisdiction (AHJ). By applying a fire risk analysis to guide the designing phase, overall fire safety of a wall assembly can be achieved more systematically as conducting FRA allows designers to clearly identify elements that are more vulnerable to fire and simply replace them with other practical options. Severity of fire risk is determined by considering the fire hazards of a wall assembly such as the exterior layer, insulation, vertical connectivity, and external ignition sources (e.g., photovoltaic panels). Frequency of fire risk is assessed based on the factors affecting fire likelihood, which are air cavity and fire-stopping applied in the design, and random design changes occurring during on-site construction. Fire risk matrix is proposed based on these fire risk factors and efforts to reduce the fire risk level associated with the wall assembly are given by systematically assessing the fire risk factors identified from fire risk analysis. Current study demonstrates how fire risk analysis can be applied to develop fire-safe walls by reducing the relevant fire risks- both severity and frequency.