• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.75-82
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• 2016

The technology of fast pyrolysis is regarded as a promising route to convert lignocellulose biomass into bio-oil which can be upgraded to transportable fuels and high quality chemical products. Despite these promises, commercialization of bio-oil for fuels and chemicals production is limited due to its notoriously undesirable characteristics, such as high and changing viscosity, high water and oxygen contents, low heating value and high acidity. Therefore, in this study quality improvement of bio-oil through vaccum distillation had been targeted. A 600 g of cork oak(Quercus variabilis) which grounded 0.8~1.4 mm was processed into bio-oil via fast pyrolysis for 1.64 seconds at $465^{\circ}C$ and temperature of vaccum distillation(100hPa) was designed to control, $40^{\circ}C$, 50, 60, 70, and 80 for 30min. Bio-oil, biochar, and gas of pyrolytic product were produced to 62.6, 18.0 and 19.3 wt%, respectively. The water content, viscosity, HHV(Higher Heating Value) and pH of bio-oil were measured to 0.9~26.1 wt%, 4.2~11.0 cSt 3,893~5,230 kcal/kg and 2.6~3.0, respectively. Despite these quality improvement, production was still limited due to its notoriously undesirable characteristics, therefore continous quality improvement will be needed in order to use practical fuel of bio-oil.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.264-270
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• 2016

This Study is to into fuel using a torrefation reaction to food waste. When the fuel of only food waste alone, fuel value is was performed at a ratio of sewage sludge constant attempts to prevent low. Mixing ratios of food waste and sewage sludge, 10:0, 8:2, 6:4, 5:5. Regardless mixing ratio, it was possible to confirm that decreases the moisture content of 10% or less at a reaction temperature of $240^{\circ}C$ or higher. As the ratio of the reaction temperature and the sewage sludge is high, the fixed carbon content is increased. It was measured at up to 36%(mixing ratios6:4, reaction temperature $270^{\circ}C$) from the initial 1.1%. From the reaction temperature $240^{\circ}C$ satisfied with 3000Kcal/Kg or more is a SRF criteria shows the calorific value. It was possible to obtain a heating value that is increased from the raw sample approximately sextuple. As reaction temperature is heightened, Van krevelen Diagram moved to the range of Lignite range. It was possible to obtain high fuel ratio and 5,500Kcal/kg or less of a combustility index as the sewage sludge mixing ratio becomes high. Increase the fixed carbon content, than those food waste alone solid fuel into and improved fuel costs, it is necessary to ensure that the quality of the fuel is improved.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.73-79
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• 2018

In this study, a torrefaction unit with a capacity of 50 kg/hr was developed and experimented to produce of solid fuel by reuse of the food and agricultural wastes. Dried food wastes and agricultural wastes were used for the experiments and the heated-air torrefaction characteristics were investigated by the raw materials, torrefaction air temperature, and torrefaction time. For the dried agricultural wastes, measured torrefaction capacity and lower heating values were 55.35 kg/hr and 3,333 kcal/kg, respectively. As the lower heating values of the treated samples were greater, by around 7.8%, than those of the non-treated samples, torrefaction process was a very effective method to increase the heating value of the agricultural waste. In case of the dried food waste, torrefaction capacity and lower heating value was measured 88.27 kg/hr and 4,016 kcal/kg, respectively. As the lower heating value of treated ones showed around 9.0% higher than that of non treated ones, torrefaction process is very effective method to increase the heating value of the agricultural waste also. It will be assumed that the heating value shows more higher as increase the air temperature and decrease the moisture content of torrified matter.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.77-83
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• 2010

In this study, we analyzed the combustion characteristics of four different floor covering materials(wood, monorium, laminatedpaper, and varnish-laminated paper) with regard to their ignitibility, thermal characteristics and flame retardancy by using an ignition temperature tester, a dual cone calorimeter, a thermogravimetric analyzer and limited oxygen index, for their fire risk assessment. According to the result, monorium had the lowest ignition temperature of $325^{\circ}C$ and the laminated paper and the varnish-laminated paper promptly ignited before 7s. Further, the wood showed the largest total heat release of $100MJ/m^2$, and the varnish-laminated paper showed the highest peak heat release rate. From the thermogravimetric analysis, it was shown that all specimens underwent rapid weight loss at $300{\sim}400^{\circ}C$. The limit oxygen indices of the laminated paper and the varnish-laminated paper were in the range of 20~21%, while it was 34% for wood. This study enabled us to confirm that wood, laminated paper and varnish-laminated paper have a relatively short ignition time and are easy to burn but they all have low heat release. In contrast, wood showed the lowest fire risk among them and had excellent flame retardancy but with high heat release.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.6
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• pp.585-592
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• 2011

The enhancement of the cold-start capability of polymer electrolyte fuel cells is of great importance in terms of the durability and reliability of fuel-cell vehicles. In this study, vanadium oxide films deposited onto the flat surface of metallic bipolar plates were synthesized to investigate the feasibility of their use as an efficient self-heating source to expedite the temperature rise during startup at subzero temperatures. Samples were prepared through the dip-coating technique using the hydrolytic sol-gel route, and the chemical compositions and microstructures of the films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and field-emission scanning electron microscopy. In addition, the electrical resistance hysteresis loop of the films was measured over a temperature range from -20 to $80^{\circ}C$ using a four-terminal technique. Experimentally, it was found that the thermal energy (Joule heating) resulting from self-heating of the films was sufficient to provide the substantial amount of energy required for thawing at subzero temperatures.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.2 s.13
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• pp.29-34
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• 2004

The time to ignition, heat release rate characteristics, and carbon monoxide yield of fiber reinforced and sandwich phenol resin were investigated with cone calorimeter. The fire characteristics of unsaturated polyester, mostly being applied to the existing passenger train, and phenolic resin were compared. DSC & TGA was used to monitor the degree of thermal decomposition and weight loss for the phenolic resin. According to the cone calorimeter data, the time to ignition was shorter, heat release rate, and CO yield was higher as the external heat flux increased. Under the same heat flux, the time to ignition of sandwich type phenolic resin was shorter than that of laminated. The result of comparison between unsaturated polyester and phenolic resin was that phenolic resin was shown to have better fire resistance than unsaturated polyester.

• Fire Science and Engineering
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• v.19 no.3 s.59
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• pp.58-63
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• 2005

Experimental measurements of flames and the product properties were performed for small kerosene pool fires. which is widely used as a fire source of laboratory scale experiments with scaling modeling. The flame length and flickering frequency were investigated for the flame structures, and compared with the theory. Three measurement methods were introduced to clarify the smoke characteristics, i.e. various gas concentrations, smoke density and thermophoretic sampling with transmission electron microscopy (TEM). The yield of carbon dioxide and the consumption of oxygen were proportional to the heat release rate of pool fires, but there is no trend on carbon monoxide emission. Smoke density of turbulent flames was exponentially increased with the heat release rate. The morphology of the soot particle was investigated to address the degree of soot maturing. The results show that the similar smoke morphology between an inverse jet flame and a pool fire exists despite of different combustion controlling mechanisms.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.2
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• pp.131-140
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• 2015

This research studied a scaling analysis for the selection of proper heat generation at tube for 1/4-scale storage vaults. First of all, the temperature field and velocity distribution of an original scale storage vault were analyzed and then numerical analysis of a 1/4-scale storage vault was performed to compare each model. The proper heat generation for a 1/4-scale storage vault, at which the temperature and velocity field of a 1/4-scale storage vault showed the best agreement with that of the original storage vault, was evaluated with proposed dimensionless parameters. The behavior of temperature and velocity of fluid in the 1/4-scale case were most similar to those of the original scale, using a heat flux 1.3 times higher than that seen in the original scale, which was approximately 190 W.

• Fire Science and Engineering
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• v.18 no.4
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• pp.57-63
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• 2004

We investigated heat properties of connection terminal in residual current protective devices(RCD) according to contact pressure for low voltage appliance. And we analyzed voltage and current waveform and oxide propagation when the poor-contact happened between terminal and wire. When contact pressure between terminal and connection wire was not applied, the heat was generated and an oxide was formed on the surface of the wire. The temperature of the insulation surrounding terminal was ascended sharply by poor-contact, micro-sparks and continuous arc sound happened in interior terminal. When the poor-contact by vibration occurred inner conductor of terminal and wire, an oxide was propagated on contact surface and the temperature was increased at 869℃. Thus, we found that the risk of electrical disaster is high in terminal and connection wire parts.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.3
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• pp.138-147
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• 2006

In this study, the composition and physico-chemical characteristics of municipal solid waste (MWS) which was treated in national park area kyungnam-do landfill were investigated. It is necessary to measure the characteristics of MSW and sludge to build a waste treatment facility, the data-base and total managing of the landfill. This MSW was composed of 34.62% of food wastes, 36.05% of papers, 15.37% of plastics & vinyls, 2.28% of textiles, 3.33% of wood, 0.49% of rubber & leathers and others, respectively. Most of MSW are composed of food, paper and plastic waste and more than 90% was combustible waste. For three components, moisture is 29.84%, combustible component is 62.30% and ash is 7.86%. The chemical element has the high order of carbon, oxygen, hydrogen on the dry basis of wastes. Also, the low heating value of the MSW which is measured by calorimeter is calculated as 2377.8kcal/kg. low heating value of the sludge is calculated as 338.06kcal/kg.