• International Journal of Railway
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• v.5 no.3
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• pp.117-123
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• 2012

According to the Intergovernmental Panel on Climate Change, combustion of petroleum-based and other fossil fuels results in the increasing atmospheric concentrations of $CO_2$ and other greenhouse gases (GHG's) and is a major contributing factor to global warming. This paper includes estimates of the energy and petroleum use and the GHG emissions caused by the transportation sector. It then examines the extent to which diversions to alternative modes may be possible. Estimates are made of the potential reductions in energy and petroleum use and GHG emissions resulting from diversions from conventional modes, to both low-speed urban and high-speed intercity maglev vehicle trips based on "well-to-wheel" (i.e. total-fuel-cycle) calculations.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.1225-1231
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• 2006

Recently, as the climate of temperature change has happened worldwide, To solve this problem, Kyoto protocol was taken to regulate global warming on Feb. 2005 and each country is making efforts to prevent global warming. In the automotive industry, R-134a refrigerant is widely used most these days because it has zero ODP(Ozone Depletion Potential). But R-134a GWP(Global Warming Potential) is so high. Therefore, replacement refrigerant desperately is needed as a alternative refrigerant. So, R-l52a is considered as one of the alternative refrigerants due to zero ODP and lower GWP against as required on Europe Committee. In this paper, performance of the air conditioning system between R-134a and R-152a is investigated experimentally. In the bench level, cooling capacity, condensing capacity, COP of automotive air conditioning system are ovaluated by means of air velocity entering the condenser and compressor revolution speed with optimized charge refrigerant quantity. Result of this study, R-152a refrigerant shows the possibility as alternative refrigerant of current R-134a in automotive air conditioning system.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.755-765
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• 2011

Nitrous oxide ($N_2O$) is one of six greenhouse gases listed up in the Kyoto Protocol, and it effects a strong global warming because of its much greater global warming potential (GWP), by 310 times over a 100-year time horizon, than $CO_2$. Although such $N_2O$ emissions from both natural and anthropogenic sources occur, the latter can be controlled using suitable abatement technologies, depending on them, to reduce $N_2O$ below acceptable or feasible levels. This paper has extensively reviewed the anthropogenic $N_2O$ emission sources and their related compositions, and the state-of-the-art non-catalytic and catalytic technologies of the emissions controls available currently to representative, large $N_2O$ emission sources, such as adipic acid production plants. Challengeable approaches to this source are discussed to promote establishment of advanced $N_2O$ emission control technologies.

• Journal of Forest and Environmental Science
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• v.25 no.3
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• pp.157-165
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• 2009

Forests potentially contribute to global climate change through their influence on the global carbon (C) cycle. The Kyoto Protocol provides for the involvement of developing countries in an atmospheric greenhouse gas reduction regime under its Clean Development Mechanism (CDM). Carbon credits are gained from reforestation and afforestation activities in developing countries. Bangladesh, a densely populated tropical country in South Asia, has a huge degraded forestland, which can be reforested by CDM projects. To realize the potential of the forestry sector in developing countries like Bangladesh for full-scale emission mitigation, the carbon sequestration potential should be integrated with the carbon trading system under the CDM of the Kyoto Protocol. This paper discusses the prospects of carbon trading in Bangladesh, in relation to the CDM, in the context of global warming.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.711-711
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• 2009

Global warming has been widely recognized as a serious problem threatening the future of human beings. It is caused by the buildup in the atmosphere of greenhouse gases, such as carbon dioxide, methane, hydrofluorocarbons (HFCs), and sulfur hexafluoride (SF6). Particularly, SF6 has extremely high global warming potential compare to those of other global warming gases. One option for mitigating this greenhouse gas is the development of an effective process for capturing and separating these gases from anthropogenic sources. In general, gas hydrates can be formed under high pressure and low temperature. However, SF6 gas is known to form hydrate under relatively milder conditions. Therefore, technological and economical effects could be expected for the separation of SF6 gas from waste gas mixtures. In this study, we carried out morphological study for the SF6 hydrate crystals to understand its formation and growth mechanisms. The observations were made in high-pressure optical cell charged with liquid water and SF6 gas at constant pressure and temperature. Initially SF6 hydrate formed at the surface between gas and liquid regions, and then subsequent dendrite crystals grew at the wall above the gas/water interface. The visual observations of crystal nucleation, migration, growth and interference were reported. The detailed growth characteristics of SF6 hydrate crystals were discussed in this study.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.1
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• pp.79-87
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• 2018

Water management impacts both methane ($CH_4$) and nitrous oxide ($N_2O$) emissions from rice paddy fields. Although irrigation is one of the most important methods for reducing $CH_4$ emission in rice production systems it can also $N_2O$ emissions and reduce crop yields. A feasibility study on the system of rice intensification (SRI) methods with respect to irrigation requirements, greenhouse gas (GHG) emissions was conducted for either 2 or 3 years depending on the treatment in Korea. The SRI methods (i.e. SRI and midsummer drainage (MD) with conventional practice (CT)) reduced the irrigation requirement by 49.0 and 22.0 %, respectively. Global warming contribution of GHG to different depending on the type of GHG. Therefore, the emission of $CH_4$ and $N_2O$ shall be converted to Global Warming Potential (GWP). The GHG emission from the conventional practice with midsummer drainage (MD) and the SRI plots, in GWP were reduced by 49.1 and 77.1 %, respectively. Application of SRI water management method could help to improve Korea's water resources and could thus contribute to mitigation of the negative effects of global warming.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.2
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• pp.99-108
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• 2023

Currently, semiconductor manufacturing industry heavily relies on a wide range of high global warming potential (GWP) gases, particularly during etching and cleaning processes, and their use and relevant carbon emissions are subject to global rules and regulations for achieving carbon neutrality by 2050. To replace high GWP gases in near future, dry etching using alternative low GWP gases is thus being under intense investigations. In this review, we report a current status and recent progress of the relevant research activities on dry etching processes using a low GWP gas. First, we review the concept of GWP itself and then introduce the difference between high and low GWP gases. Although most of the studies have concentrated on potentially replaceable additive gases such as C₄F₈, an ultimate solution with a lower GWP for main etching gases including CF₄ should be developed; therefore, we provide our own perspective in this regard. Finally, we summarize the advanced dry etch process research with low GWP gases and list up several issues to be considered in future research.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.992-996
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• 2008

In this study, changes in precipitation across South Korea during snow seasons (November-April) and their potential are examined. Current (1973/74-2006/07) and future (2081-2100) time series of snow indices including snow season, snow-to-precipitation ratio, and snow impossible day are extracted from observed snow and precipitation data for 61 weather stations as well as observed and modeled daily temperature data. Analyses of linear trends reveal that snow seasons have shortened by 3-13 days/decade; that the snow-to-precipitation ratio (the percentage of snow days relative to precipitation days) has decreased by 4-8 %/decade. These changes are associated with pronounced formations of a positive pressure anomaly core over East Asia during the positive Arctic Oscillation winter years since the late 1980s. A snow-temperature statistical model demonstrates that the warming due to the positive core winter intensifies changes from snow to rain at the rate of $4.7cm/^{\circ}C$. The high pressure anomaly pattern has also contributed to decreases of air-sea thermal gradient which are associated with the reduction of snow could formation. Modeled data predict that a fingerprint of wintertime global warming causing changes from snow to rain will continue to be observed over the 21st century.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.3
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• pp.181-193
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• 2023

In this study, we conducted a comparative life cycle assessment (LCA) of two different products, considering reusable and single-use packaging for fresh food distribution. For reusable packaging, we utilized expanded polyethylene (EPE), while for comparison, a disposable box made of widely used expanded polystyrene (EPS) was selected. We comprehensively analyzed the environmental impacts of production, transportation, reprocessing (for reused boxes), and disposal across 18 impact categories. Upon analyzing the actual reuse of 300 rounds of fresh food, the cumulative global warming potential (GWP) values for the EPE box were found to be 280.21 kg carbon dioxide (CO₂) eq, demonstrating a significant 75% reduction compared to those of the EPS box. Furthermore, it was observed that the GWP values for the EPE boxes became equivalent to those of the EPS boxes after 12 rounds of reuse. In conclusion, reusable packaging shows substantial potential to contribute to the reduction of environmental burdens, aligning well with global environmental requirements for sustainable food distribution and related industries.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.4
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• pp.332-340
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• 2002

In these days, environmental concerns have been increased throughout the industry and community worldwide. To prevent the ozone depletion, ozone depletion potential of a refrigerant must be zero. Simultaneously, a refrigerant with low GWP (global warming potential) is very demanding to induce green house effect. Chlorine-free HFC-l34a is a refrigerant widely used for automotive air-conditioning system because its destruction potential is ecologically zero. Although HFC-l34a has no ozone depletion potential, its global warming potential is so high that it is not considered as a perfect alternative refrigerant that is acceptable for long-term use. In this paper, experimental measurement has been carried out to analyze the performance characteristics of automotive air-conditioning system using HFC-152a, which has low GWP and zero ODP. Also mixed refrigerant that is composed of HFC-152a and $CF_3$ was applied to investigate an alternative possibility for the automotive airconditioning system. As a result of this study, we could draw following conclusions; With respect to the variation of the rotational speed of compressor, outside air temperature and flow rate, the heat amount of evaporator and compressor and performance coefficient was varied.