• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.701-711
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• 2020

Purpose: In this study, the risk of flammability of a liquid mixture was experimentally confirmed because the purpose of this study was to confirm the increase or decrease of the flammability risk in a mixture of two substances (combustible+combustible) and to present the risk of the mixture. Method: Flash point test method and result processing were tested based on KS M 2010-2008, a tag sealing test method used as a flash point test method for crude oil and petroleum products. The manufacturer of the equipment used in this experiment was Japan's TANAKA. The flash point was measured with a test equipment that satisfies the test standards of KS M 2010 with equipment produced by the company, and LP gas was used as the ignition source and water as the cooling water. In addition, when measuring the flash point, the temperature of the cooling water was tested using cooling water of about 2℃. Results: First of all, in the case of flammable + combustible mixtures, there was little change in flash point if the flash point difference between the two substances was not large, and if the flash point difference between the two substances was low, the flash point tended to increase as the number of substances with high flash point increased. However, in the case of toluene and methanol, the flash point of the mixture was lower than that of the material with a lower flash point. Also, in the case of a paint thinner, it was not easy to predict the flash point of the material because it was composed of a mixture, but as a result of experimental measurement, it was measured between -24℃ and 7℃. Conclusion: The results of this study are to determine the risk of mixtures through experimental studies on flammable mixtures for the purpose of securing the effectiveness of the details of the criteria for determining dangerous goods in the existing dangerous goods safety management method and securing the reliability and reproducibility of the determination of dangerous goods Criteria have been presented, and reference data on experimental criteria for flammable liquids that are regulated in firefighting sites can be provided. In addition, if this study accumulates know-how on differences in test methods, it is expected that it can be used as a basis for research on risk assessment of dangerous goods and as a basis for research on dangerous goods determination.

• Fire Science and Engineering
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• v.22 no.3
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• pp.252-257
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• 2008

With the rapid exuberant growth of the forest, the number and size of forest fires and the costs of wildland fires have increased. The flame spread rate of forest fires is depending on the environmental variables like the wind velocity, moisture of grassland, etc. If we know the effects of the environmental variables on the fire growth, it is useful for wildland fiIre suppression. But analysis of the spread rate of wildland fire for these effects have not been established. In this study, the effects of wind velocity and height of grassland fuel have been investigated using the WFDS which is developed at NIST for prediction of the spread of wildland fires. The results showed that the relation between the height of the fuel and the spread rate of the head fires is, and the spread rates related to the wind velocity are predicted 17% less than the experimental results of Australia. When the wind velocity is over 7.5m/s, the concentration of pyrolyzed gas phase fuel is getting low due to fast movement of pyrolyzed gas, the flame spread rate becomes slow.

• Journal of dental hygiene science
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• v.10 no.1
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• pp.45-54
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• 2010

The purpose of this study was to offer the importance on factors of selecting dental institution according to general characteristics targeting general dental patients, and the information of having important influence upon choosing dental clinic and dental hospital. The survey was carried out from August 2009 to September. As a result of analyzing SAS(ver 9.1), the following conclusions were obtained. In the importance on factors of selecting dental institution according to general characteristics, it was thought to be important in convenience of movement or mobility such as distance, transportation, and parking convenience according to age level. According to final academic background, the importance in a factor of rumor in dental clinic was high(p < 0.05). According to job, the significant difference was shown in rumor of dentistry and parking convenience(p < 0.05). According to income, the factor in the appearance of training a medical specialist was indicated to be statistically higher in the group with over 5 million won than the group with under 2 million won(p < 0.05). Given seeing the distribution of opinion about dental hospitals (comparison with dental clinics), the excellence in the medical staff's ability was indicated to be the highest in all of the factor of influencing the use satisfaction(${\beta}=0.18$), the factor of influencing the recommendation level(${\beta}=0.21$), and the factor of influencing the re-use intention(OR=2.09).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.4
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• pp.405-412
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• 2012

In the MCFC power generation system, the combustor supplies a high temperature mixture of gases to the cathode and heat to the reformer by using the off-gas from the anode; the off-gas includes high concentrations of $H_2O$ and $CO_2$. Since a combustor needs to be operated in a very lean condition and avoid local heating, a catalytic combustor is usually adopted. Catalytic combustion is also generally accepted as one of the environmentally preferred alternatives for generation of heat and power from fossil fuels because of its complete combustion and low emissions of pollutants such as CO, UHC, and $NO_x$. In this study, experiments were conducted on catalytic combustion behavior in the presence of Pd-based catalysts for the BOP (Balance Of Plant) of 5 kW MCFC (Molten Carbonate Fuel Cell) power generation systems. Extensive investigations were carried out on the catalyst performance with the gaseous $CH_4$ fuel by changing such various parameters as $H_2$ addition, inlet temperature, excess air ratio, space velocity, catalyst type, and start-up schedule of the pilot system adopted in the BOP.

• Journal of the Korean Institute of Gas
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• v.17 no.6
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• pp.39-45
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• 2013

The gas generated from the fire which is continuous until material is completely burned. We can analyze usual gas using chromatography analysis but it can not be applicated to analyze for the gas from the fire because which gas is enormously generated. Besides, chromatography analysis has the disadvantage that it can not continuously analyze the sample's representativness, gas from the fire, Fourier transform infrared spectroscopy, FT-IR, has been utilized for effective combustion gas analysis method in small-scale combustion and on-line analysis has been attempted continuously. However, continuous sampling of 3.5l/min can not be representativness of sample if the gas caused by a massive fire and space. And the gas sampling is practically impossible in such a case. In this study, we attempted remote analysis while overcoming the disadvantages of the current gas analysis by using an Open-Path Infrared Analyzer without pre-treatment of the sampling. For the remote analysis, quantitative analysis method was established regarding each combustion toxic gases. And we measured the gases from the fire that occurs in the real case.

• Fire Science and Engineering
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• v.33 no.6
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• pp.87-94
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• 2019

Through a press release dated July 17, 2018, the Anti-Corruption and Civil Rights Commission recommended that the National Fire Agency develop preventive measures against fire in the "Indoor Archery Ground" and "Room Escape Café" etc., which were originally excluded from the category of "Publicly Used Establishments." This study developed the hierarchy of domains and indicators of measurement for fire risk assessment of the new business of publicly used establishments through the Delphi Method. It analyzed the goodness of fit scores (over 3.00) and secured an average score of 4.25. Using AHP analysis, the ratio of consistency for the domains of measurement of fire risk assessment was found to be 4.0%, which was lower than CR ≤ 0.1 (10%). The consistency of subsequent measurement indicators were distributed in the range of 0.1%~3.6%, and they were identified as being commonly consistent. The indicators of measurement appeared as follows in order of importance and priority: Type of Internal Passage of Establishment and Evacuation Capacity of Exit (0.316), Control of Ignition Source (0.141), Inherent Risk (0.106), Appropriateness and Adaptiveness of Fire Detection System (0.097), Control of Inflammables/Combustibles (0.084), Guides and Facilities helping Evacuation (0.075), Fire Resistant Structure and Finishing Materials (0.060), Compartmentalization and Emergency Exit (0.049), Risk of Fire Expansion (0.046), and Appropriateness and Adaptiveness of Fire Extinguishing Facilities (0.026). The findings of this study are expected to be expansively used as data for future research on the development of fire risk assessment indicators.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.154-160
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• 2020

This study analyzed the fire intensity according to the zones classification between traditional market stores using FDS software. Modeling was conducted for the Seomoon traditional market district 4 at Daegu, which places combustibles, such as textiles and clothing near the passageway. The first ignition point assumed a short circuit fire situation at the fourth store combustible. The analysis was conducted under similar conditions as the fire situation in 2016. When there was no section wall, the fire spread rapidly through radiation in all directions from the fire-origin point. After 600 seconds, the mall was burnt to the ground. When section walls were present, however, the fire could be restricted inside the compartment. The first intensity of the two analysis conditions was predicted from the total heat energy from 200 seconds (X₁) to 600 seconds (X₂), where the heat generation rate began to increase rapidly. As a result of installing section walls near the fire point, heat energy generation of approximately 11.12 MW (55.68 %) was delayed. Further analysis of smoke control, according to the section wall arrangement and re-installation facilities, will be needed to study the characteristics of fire in traditional markets comprehensively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.3
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• pp.251-257
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• 2012

This work presents an experimental investigation of NOx emissions according to inlet air temperature (550-660 K), stoichiometric air ratio (${\lambda}$, 1.4-2.1), and elevated pressure (2-5 bar) in a High Press Combustor (HPC) equipped with a double cone burner, which was designed by Pusan Clean Coal Center (PC3). The exhaust-gas temperature and NOx emissions were measured at the end of the combustion chamber. The NOx emissions generally decreased as a function of increasing ${\lambda}$. On the other hand, NOx emissions were influenced by ${\lambda}$, inlet air temperature and pressure of the combustion chamber. In particular, when the inlet air temperature increased, the flammability limit was extended to leaner conditions. As a result, a higher adiabatic temperature and lower NOx emissions could be achieved under these operation conditions. The NOx emissions that were governed by thermal NOx were greatly increased under elevated pressures, and slightly increased at sufficiently low fuel concentrations (${\lambda}$ >1.8).

• Journal of Life Science
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• v.28 no.6
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• pp.681-687
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• 2018

Recently, several researchers have been developing cosmetics from natural ingredients for skin whitening and anti-aging products. The red sea cucumber (RSC), Apostichopus japonicas, is a species of sea cucumber in the family stichopodiae, which is widely distributed in China, Japan, and Korea. To use Red Sea Cucumber as a cosmetic ingredient, its inhibitory effects on melanogenesis and the anti-aging effects of RSC extracts were investigated. First, a tyrosinase activity assay was performed, which showed that RSC inhibited tyrosinase activity at a concentration of $200{\mu}g/ml$. An MTT assay was carried out to evaluate cell toxicity, and the results showed that RSC extract has no cytotoxicity in HaCaT cells. Furthermore, the mRNA expression levels of tyrosinase, tyrosinase related protein 1 (TRP-1), tyrosinase related protein 2 (TRP-2), microphthalmia-associated transcription factor (MITF), and matrix metalloproteinase (MMPs) genes treated with RSC extract in B16F10 and HaCaT cells decreased. Moreover, a wound-healing assay was performed to identify the cell regeneration effect of RSC extracts. Also, a skin turnover effect was confirmed by creating a three-dimensional cell culture with HaCaT and human fibroblasts. Altogether, the results suggested that Red Sea Cucumber may possess a high ability to induce whitening and anti-wrinkle effects as a cosmeceutical ingredient.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.31-36
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• 1997

This study was carried out to analyze the composition of landfill generation gas using vertical pipe wells installed at landfill. The characteristics of composed waste were examined by the open-cut test at H. landfill in Pusan. The waste compositions of landfill layer by Open-cut test indicated that organic matter was average $4.6{\sim}8.78%$ in each landfill. $CH_4$ compositions of gas in each landfill were $49.71{\sim}50.45%$(A-point), $50.39{\sim}53.74%$(B-point), and $58.76{\sim}61.62%(C-point), respectively. The chemical formula of organic matter left in the underground was $C_{36.3}H_{76}O_{30}N_{0.3}S_{0.1}$ Underground temperatures were changed to $18.8{\sim}25.8^{\circ}C$ when the ambient temperature was about $13.4^{\circ}C$. Temperatures with passed times in A, B and C-lysimeter were about $21.1{\sim}22.5^{\circ}C,\;30{\sim}32.5^{\circ}C$ and $35{\sim}38.5^{\circ}C$, respectively. After about 65 day, decomposition rates of organic matter in A, B and C-lysimeter were 9.9%, 14.9% and 22.3%, respectively.