• Journal of Korean Society of Transportation
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• v.33 no.4
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• pp.357-367
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• 2015

This study aims to propose integrated management strategies based on the relationship between co-benefits and total benefits of greenhouse gases and air pollutant emissions for establishing a transport and environmental policy. The results show that the integrated management of the following policies: 'Car Free Day' and 'Early Scrapping of Decrepit Diesel Vehicle', which are used for reducing reduce gasoline and diesel, can together reduce both PM and $CO_2$ emissions and increase total benefits. In addition, the integrated management of 'Car Free Day' with environment policies and 'Congestion Charge' with environment policies simultaneously controls the three factors which influence emissions, including travel volume, travel speed and emissions factor, and was found to be effective in terms of co-benefits. This study reduces both air pollutants, which are harmful to health, and greenhouse gas emissions, which influence climate change, and improves the efficiency of policy through the integrated management of policies.

• Environmental and Resource Economics Review
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• v.23 no.2
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• pp.157-185
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• 2014

The Kyoto Protocol has extended its life until 2020 by the decision at COP18 in Doha, Qatar in 2012. So has the Kyoto Mechanism of CDM, JI, and ETS. Nonetheless, the sustainability of CDM projects is jeopardized by the recent rule changes in the international emissions trade market such as EU ETS and the price decrease in emission credits. In particular, the domestic CDM projects reducing non-$CO_2$ GHG emissions are being directly affected. This study examines the trend of carbon credit price change in the international market. It also examines how the rule changes in the international emissions trade market have affected domestic non-$CO_2$ CDM projects through which mechanisms. The policy implications drawn from this study is two-fold: it suggests how the government can assist the project developers in utilizing GHG emission reduction technologies and the market in promoting investment environment before the domestic ETS enters into effect in 2015; apart from possible measures within ETS, an additional measures such as bilateral carbon offset system is suggested to help the private sector reduce uncertainty in investment and increase options to choose.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.533-540
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• 2010

Effects of pH (1.8-10.2) and time (56 sec-15 min 4 sec) at high hydrostatic pressure (500 MPa) on the reduction of volatile compounds in garlic were studied. Volatile components of garlic were obtained from the headspace, analyzed, and identified by gas chromatography (GC)-mass spectrometry and an electronic nose. Nineteen sulfur compounds were identified as major compounds in garlic, and furan, aldehydes, alcohols, and ketones were also detected. Off-flavor compounds were more effectively reduced under strong acidic conditions. As the residence time at 500 MPa increased from 56 sec to 15 min 4 sec, the total amount of volatile compounds decreased significantly. The total amount of sulfur compounds decreased about 70% compared to those of raw garlic when the garlic was soaked in buffer (pH 6.0) and treated at 500 MPa for 15 min 4 sec. A principal component analysis showed that the off-flavors of garlic were reduced by the operating time of high hydrostatic pressure as well as pH treatment. The correlation coefficient of the results between GC and the electronic nose analysis was 0.9620. Therefore, pH and high hydrostatic pressure treatment could be used as an efficient method for reducing of garlic off-flavor.

• Analytical Science and Technology
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• v.13 no.6
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• pp.751-758
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• 2000

A study was carried out on the dissolution of spent PWR fuels and performed on the fuels and the separation of iodide for the quantitative analysis using SIMFUEL which has chemical composition of a simulated spent PWR fuel (burn-up; 35,000 MWd/MTU and cooling time; 10 years). To dissolve the SIMFUEL effectively and to minimize the formation of volatile iodine through dissolution process, the optimum ratio of mixed acid ($HNO_3/HCl$ 80: 20 mol%) was established and ozone gas was purged. In the separation step of iodine with $CCl_4$, $NH_2OH{\cdot}HCl$ was used for reducing ${IO_3}^-$ to $I_2$.The optimum acidity of the dissolved solution and the added of $NH_2OH{\cdot}HCl$ were 2.5 M and more than $1.5{\times}10^{-3}mole$, respectively. The recovery of iodide by ion chromatography was $82.8{\pm}4.1%$ and the total yield was corrected by gamma spectrometery using $^{131}I$ as a tracer.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.42-47
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• 2015

While the oxygen content of gasoline for automobiles in Korea is regulated to less than 2.3 weight %, European and World-Wide Fuel Charter (WWFC) regulate it to less than 2.7 weight %. The oxygen content of oxygen-containing materials increases the octane number of the fuel due to the secondary combustion in the internal combustion engine. It has been reported to be effective in reducing emissions, such as CO, HC, which is caused by incomplete combustion. Before 2000s in the United States and Europe, there has been many researches about vehicle application of the changes in oxygen content of gasoline. However, there are not many domestic researches which reflect the improvement of the fuel quality and automotive technology. In this study, fuels of three different oxygen contents were applied to GDI and MPI engines. As a result, the changes of fuel consumption and emission gas were very similar depends of the oxygen content changes. The PN in GDI engine was decreased as the oxygen content was increased.

• Journal of Life Science
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• v.21 no.3
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• pp.444-450
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• 2011

Perchlorate ($ClO_4^-$) is a contaminant found in surface water and soil/ground water. Autotrophic perchlorate-reducing bacteria (PRB) use hydrogen gas ($H_2$) as an electron donor to remove perchlorate. Since iron corrosion can produce $H_2$, feasibility of autotrophic perchlorate-removal using zero-valent iron (ZVI) was examined in this study using activated sludge that is easily available from a wastewater treatment plant. Batch test showed that activated sludge microorganisms could successfully degrade perchlorate in the presence of ZVI. The perchlorate biodegradation was confirmed by molar yield of $Cl^-$ as perchlorate was degraded. Scanning electron microscope revealed that rod-shaped microorganisms on the surface of iron particles used for the autotrophic perchlorate-removal, suggesting that iron particles could serve as supporting media for the formation of biofilm as well. DGGE analyses revealed that microbial profile of the inoculum (activated sludge) was different from that of biofilm sample obtained from the ZVI-added enrichment culture used for $ClO_4^-$-degradation. A major band of the biofilm sample was most closely related to the class Clostridia.

• Food Science and Preservation
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• v.21 no.1
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• pp.17-24
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• 2014

This study was conducted in order to evaluate the effect of postharvest ripening periods and packaging methods on maintaining the quality of fresh-cut winter squash. Winter squash (var. Bouchang) was ripened at $22^{\circ}C$ for 1 or 2 weeks after harvest. The samples were washed in tap water, sanitized in $100{\mu}L/L$ chlorine water, peeled, and cut into 16 parts. Samples were then vacuum packaged or non-vacuum packaged in $80{\mu}m$ nylon/polyethylene (Ny/PE) films and stored at $5^{\circ}C$ for 21 days. Results indicated that different postharvest ripening periods affected gas concentration, firmness, off-odor development, color, and overall quality of fresh-cut winter squash. Samples treated with 2-week ripening periods maintained quality with higher redness value and soluble solid content (SSC) and lower $CO_2$ concentration and off-odor development compared to samples treated with a 1-week ripening period. Non vacuum packaging was effective in increasing visual quality and reducing off-odor development. A combination treatment of 2-week ripening periods and non-vacuum packaging maintained good quality with the lowest off-odor development and the highest visual quality scores at the end of the storage period.

• Journal of Life Science
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• v.24 no.3
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• pp.266-273
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• 2014

In the present study, the chemical compositions and antimicrobial and antioxidant activities of commercially available essential oils in Korea were investigated. The essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS). The results demonstrated that they exhibit a broad spectrum of antimicrobial activities against gram positive, gram negative, and multidrug resistant (MDR) strains. The antimicrobial activity of five of the essential oils against 40 organisms was assessed using the minimum inhibitory concentration (MIC). The MIC values were in the ranges of 0.0625-0.5% (v/w) for lemongrass and manuka, 0.03125-1.0% (v/w) for tea tree, 0.0625-1.0% (v/w) for thyme, and 1-4% (v/w) for ravensara, depending on the pathogens studied. This study revealed that, among the essential oils tested, lemongrass and thyme oil showed broad antimicrobial activity against infectious bacteria. The antioxidant activities and the reducing power of the essential oils were determined with a 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay. Thyme oil exhibited the strongest antioxidant activity comparing with ascorbic acid. This is the first report on the chemical compositions and antimicrobial activities of commercially available essential oils against infectious bacteria and MDR strains acquired from Korean hospitals.

• Fire Science and Engineering
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• v.33 no.4
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• pp.16-27
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• 2019

A burning test was conducted on the smoke and combustion gases generated from cypress wood treated with sodium silicate, 3-aminopropyltrimethoxysilane sol, 3-(2-aminoethylamino)propylmethyldimethoxysilane sol, and 3-(2-aminoethylamino) propyltrimethoxysilane sol. The silicone compound sol was applied to each of the cypress wood specimens three times with a brush. The smoke and combustion generation gas were analyzed using a cone calorimeter (ISO 5660-1) and the smoke was also evaluated by applying new smoke risk assessment method. The smoke performance index (SPI) of the cypress treated with silicone compound increased 1.66 to 8.42 times and the smoke growth index (SGI) was 11.8 to 88.2%, respectively. The smoke intensity (SI) is expected to be 1.0~50.5% lower than that of the base specimens, resulting in lower smoke and fire hazards. The third maximum carbon monoxide (CO_peak) concentration of the specimens treated with silicone compounds was 22.5~33.3% lower than that of the base specimens. On the other hand, it produced potentially fatal toxicity that was 1.48~1.72 times higher than the US Occupational Safety and Health Administration (OSHA) acceptance standard (PEL). Cypress wood itself produced a high carbon monoxide concentration, but the silicon compound played a role in reducing this level.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.3
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• pp.10-21
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• 2006

The aim in this study is to develop the combined EGR system with a non-thermal plasma reactor for reducing exhaust emissions and improving fuel economy in turbo intercooler ECU common-rail diesel engines. At the first step, in this paper, the characteristics of performance and $NO_x{\cdot}THC$ emissions under four kinds of engine loads are experimentally investigated by using a four-cycle, four-cylinder, direct injection type, water-cooled turbo intercooler ECU common-rail diesel engine with a combined plasma exhaust gas recirculation(EGR) system operating at three kinds of engine speeds. The EGR system is used to reduce $NO_x$ emissions, and the non-thermal plasma reactor and turbo intercooler system are used to reduce THC emissions. The plasma system is a flat-to-flat type reactor operated by a plasma power supply. The fuel is sprayed by pilot and main injections at the variable injection timing between BTDC $15^{\circ}$ and ATDC $1^{\circ}$ according to experimental conditions. It is found that the specific fuel consumption rate with EGR is increased, but the fuel economy is better than that of mechanical injection type diesel engine as compared with the same output. Results show that $NO_x$ emissions are decreased, but THC emissions are increased, as the EGR rate is elevated. $NO_x$ and THC emissions are also slightly decreased as the applied electrical voltage of the non-thermal plasma reactor is elevated. Thus one can conclude that the influence of EGR in $NO_x$ and THC emissions is larger than that of the non-thermal plasma reactor, but THC emissions are greatly influenced by the non-thermal plasma reactor as the EGR rate is elevated.