• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2563-2566
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• 2011

Government has presented a guideline for the calculation of carbon emission with infrastructures in 2011, which aims to manage the GHG(greenhouse gas) emission of construction sector. Generally, the main emission sources of construction works are divided into the fuel consumption of equipments and the use of materials. This study investigated the characteristics of GHG emission with the use of equipments under the construction of railroad track. Track types are classified into ballasted track and concrete track. As a result, the specific GHG emission on the construction of ballasted track at the A line was 39.53 ton $CO_{2e}/km$ and concrete track was 25.54 ton $CO_{2e}/km$. Ballasted track showed higher specific GHG emission than concrete track because of the additional construction works by the use of gravels. In future, it is necessary to study the comparison of GHG emissions with construction methods including the use of materials. Based on these results, the low carbon construction of railroad will be established continuously.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.668-671
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• 2005

Carbon nanotubes exhibit strong fluorescence emissions in the region of near infrared regions where most biomolecules are transparent. Such signals are highly sensitive to environment variations as well as adsorption of specific biomolecules. In this research, single walled carbon nanotubes(SWNTs) are assembled with different types of DNAs and used to target specific types of DNAs. Dot blot investigations and corresponding raman spectroscopy observations demonstrated excellent selectivity of carbon nanotube-DNA bioconjugates. The results show possibility of using SWNT as generic nano-bio markers for precise detection of different kinds of genes.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.43-48
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• 2008

The exhaust emissions of diesel engine are recognized as a major cause influencing environment strongly. In this study, the possibility of biodiesel fuel and oxygenated fuel(dimethoxy methane; DMM) was investigated as an alternative fuel for a naturally aspirated direct injection diesel engine. The smoke emission of blending fuel(biodiesel fuel 90vol-%+DMM 10vol-%) was reduced approximately 70% at 2500rpm, full load, in comparison with the diesel fuel. But, power, torque and brake specific energy consumption showed no significant differences. But, NOx emission of biodiesel fuel and DMM blended fuel increased compared with commercial diesel fuel due to the oxygen component in the fuel. It was needed a NOx reduction counterplan that EGR method was used as a countermeasure for NOx reduction. It was found that simultaneous reduction of smoke and NOx emission was achieved with BDF(95 vol-%) and DMM(5 vol-%) blended fuel and cooled EGR method(15%).

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3013-3018
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• 2008

Supercharging system was adopted to investigate the influence of boost pressure on operating range, brake specific fuel consumption (BSFC) and exhaust emissions by using a supercharger at low temperature diesel combustion (LTC) condition in a 5-cylinder 2.7 L direct injection diesel engine. The experimental parameters such as injection quantity, injection timing, injection pressure and exhaust gas recirculation (EGR) rate were varied to find maximum operating range. The result showed that operating range with boost was expanded up to 41.9% compared to naturally aspirated LTC condition due to increased mixing intensity. The boosted LTC engine showed low BSFC value and dramatically reduced soot emission under all operating range compared with high speed direct injection (HSDI) mode. Finally, this paper presents the boosted LTC map of emission and the strategy of improved engine operating range.

• Advances in Energy Research
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• v.3 no.3
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• pp.167-179
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• 2015

This paper presents a techno-economic analysis of a partial repowering scheme for an existing 210 MW coal fired power plant by integrating a gas turbine and by employing waste heat recovery. In this repowering scheme, one of the four operating coal mills is taken out and a new natural gas fired gas turbine (GT) block is considered to be integrated, whose exhaust is fed to the furnace of the existing boiler. Feedwater heating is proposed through the utilization of waste heat of the boiler exhaust gas. From the thermodynamic analysis it is seen that the proposed repowering scheme helps to increase the plant capacity by about 28% and the overall efficiency by 27%. It also results in 21% reduction in the plant heat rate and 29% reduction in the specific $CO_2$ emissions. The economic analysis reveals that the partial repowering scheme is cost effective resulting in a reduction of the unit cost of electricity (UCOE) by 8.4%. The economic analysis further shows that the UCOE of the repowered plant is lower than that of a new green-field power plant of similar capacity.

• Journal of Climate Change Research
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• v.5 no.3
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• pp.199-208
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• 2014

According to "IPCC guide line for national greenhouse gas inventories" each country should develop the 'Country-specific emission factor' and apply it to estimate greenhouse gases emissions from landfill. It could reflect properties of country and make estimation more accurate. For that accuracy, developed country-specific emission factor should be assessed and be verified consistently. Developed emission factors should be assessed in terms of Representative, Emission Property, Accuracy and Uncertainty, but there is no study about weighted assessment factors under each emission variable. This study do survey targeting public officials, professors and other experts for Analytical Hierarchy Process(AHP), mostly use to make decisions, to weight assessment factors. We investigated the weighted values per Emission factor for Representative, Emission property, Accuracy and Uncertainty on AHP survey, and Representative factor was the highest, and then in the order of Emission property (0.26), Accuracy(0.22), Uncertainty (0.15).

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.1
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• pp.69-76
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• 2023

An experimental study was conducted on a 4-stroke direct injection diesel engine to examine the combustion and emission characteristics of 1-octanol/diesel fuel blends. The concentration of 1-octanol in the fuel blends was 10%, 30%, and 50% by volume. Experiments were conducted by varying the engine torque from 6 Nm to 12 Nm at the same engine speed of 2,700 rpm. Results showed that the fuel conversion efficiency increased as the 1-octanol proportion increased under most experimental conditions. However, the brake specific fuel consumption increased due to the relatively low lower heating value of 1-octanol. The smoke opacity and the concentrations of NO_x and CO emissions generally decreased with brake mean effective pressure as the 1-octanol proportion increased. On the other hand, the unburned hydrocarbon concentration increased with an ascending ratio of 1-octanol.

• Journal of the korean Society of Automotive Engineers
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• v.7 no.2
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• pp.64-79
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• 1985

Engine performances and emission characteristics were investigated, using a experimental single cylinder engine with methanol-LPG(butane) fuel blend. The results were compared with the case of neat methanol and gasoline. The blending ratio of methanol to LPG was reasonable at 90 : 10(M90) and in using M90, the engine performances including output, brake specific fuel consumption and brake thermal efficiency, were better than those of neat methanol and gasoline. CO emission of M90 was lower than that of meat methanol by 15% and lower than that of gasoline by 35%. HC emission of M90 was also lower than that of gasoline by 46-85% in the whole range of .phi. The concentration of NOx emission of M90 was lower than that of gasoline and higher than that of neat methanol.

• Hwankyungkyoyuk
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• v.10 no.2
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• pp.325-338
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• 1997

Review of the global change in various energy usages and resulting environmental impacts were made in terms of population increase, economic development and energy consumption. Greater use of fossil fuels in past couple of centuries give rise to acid rain and gradual climate changes mainly due to Green House inducing gases emissions from fossil fuel combustion. In view of the forthcoming Kyoto conference in December, various alternative options were assessed. To cope with rapidly developing robust Korean economy, the alternative energy options for the sustainable development in 21st Century would be the wider use of Nuclear Energy in parallel with constrained use of fossil fuel and renewable energy development. However there are many hurdles to overcome. One of the most important element is to improve public acceptability of those alternatives. Since public acceptance depend heavily upon individual perception on specific energy technology applications, the basic energy technologies education from primary up to high school education and the related curriculum organization is important. The suggested improvement in education for Nuclear Energy Application was made on the basis of advanced industrial countries with substantial Nuclear Energy Application programs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.296-297
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• 2014

United Nations Framework Convention on Climate Change(UNFCCC), an international treaty to prevent the regulation and global warming, has passed through the General Assembly for 17 times from 1992 to 2011. To create a performance plan specific, such as the Kyoto Protocol, it is to promote the reduction of energy consumption and greenhouse gases worldwide. In South Korea, Korea Infrastructure Safety and Technology Corporation(KISTEC) is working and supporting for developing method of green remodeling policy. Among several solutions, "Remodeling" ensures to increase the energy efficiency of buildings and to reduce the emissions of greenhouse gases, and consequently it could maintain buildings high efficiency. For remodeling projects, it is most important to determine construction plan including remodeling scopes and methods, while the plan has been determined by the engineer's background and experience. Therefore, this study aims at developing a method for selecting optimal skin system which has remarkable influence to energy performance of the buildings.