• 환경영향평가
• /
• 제21권3호
• /
• pp.409-415
• /
• 2012

Post-kyoto regime has been discussing with the GHG reduction commitment. GHG energy target management system also has been applied for the domestic measures in the country. Universities are major emission sources for GHG. It is very important for campus to built the GHG inventory system and estimate the potential GHG emission reduction. In general, GHG inventory on the campus was taken by the IPCC guidance with the classification of scope 1, 2, and 3. Electricity was the highest portion of GHG emission on the campus as 5,053.90 $tonsCO_2eq/yr$ in 2009. Manufacturing sector was the second high emission and meant GHG in laboratory. Potential GHG reduction was planned by several assumptions such as installation of occupancy sensor, exchanging LED lamp and photovoltaic power generation. These reduction scenarios was simulated by LEAP model. In 2020, outlook of GHG emission was estimated by 17,435.98 tons of $CO_2$ without any plans of reduction. If the reduction scenarios was applied in 2020, GHG emission would be 16,507.60 tons of $CO_2$ as 5.3% potential reduction.

• Environmental Analysis Health and Toxicology
• /
• 제19권2호
• /
• pp.227-233
• /
• 2004

The main objectives of this study were to identify from literature review the potential sources and to provide a preliminary national emission inventory for the unintentionally produced polychlorinated biphenyls (PCBs) (i.e., by - product PCBs). In Korea, fuel combustion, waste combustion, thermal industrial processes, and transportation were identified as potential sources of by -product PCB s. According to the availability of the emission factors and/or activity data, emission inventory could be assessed only for fuel combustion, waste combustion, steel industry, non-ferrous industry, and non-metallurgical industry. The total national emission of by-product PCBs was estimated to be 1087kg for the year 2000. The preliminary estimation further indicated that the steel manufacturing was the single dominant emission category, contributing 93％ to the total emission. Of the steel manufacturing processes, the contribution of the electric arc furnace was about 80％ of the total emission. Due to high uncertainty associated with both the emission factors and activity statistics, the emission estimates in this study are likely to contain significant errors. However, the results of the present work could serve the first step toward future efforts to establish national source and emission inventories of by-product PCBs.

• 한국기후변화학회지
• /
• 제5권3호
• /
• pp.219-230
• /
• 2014

In this study, greenhouse gas emission of magnesium industry was estimated and the reduction potential of the greenhouse gas emission was evaluated with reduction technologies. Default value of IPCC guideline was used to calculate the greenhouse gas emission and $SF_6$ alternatives were considered in reduction potential. Import of magnesium ingot was 22,806 ton in 2013, which will be expected to increase to 81,700 ton with 20% rate in 2020. Magnesium ingot was consumed to produce magnesium alloy in diecasting process. Recently, commercial production of crown magnesium and magensium plate began. Based on ingot consumption, $CO_2$ emission of domestic magnesium industry was estimated to 504,000 ton, which is about 0.79% of domestic industrial emissions. Reduction potential of diecasting process was estimated to 489,320 ton by changing SF6 to alternative gases such as HFC-134a, Novec-612. Emission factor of Tier 3 level should be developed to enhance the accuracy of greeenhouse gas emission of magnesium industry.

• 전기학회논문지
• /
• 제64권5호
• /
• pp.732-738
• /
• 2015

In ac discharge, emission efficiency shows an time-varying characteristics during discharge. The phenomenon is caused by the potential distribution changes during the discharge, which indicates that a specific potential distribution can contribute to a high improvement of the emission efficiency. To create an artificial environment for a potential distribution favorable to emission efficiency, we used the asymmetric electrode structure and proved the capability. Our results showed that the ratio of the area of anode to cathode became larger, the emission efficacy was greatly improved.

• 한국토양비료학회지
• /
• 제45권6호
• /
• pp.1187-1193
• /
• 2012

Water control is mainly one of the key factors that can affect nitrous oxide ($N_2O$) emissions from soils. This study was undertaken to determine the effect of intermittent drainage compared to continuous flooding (conventional water regime) on $N_2O$ emission to global warming potential (GWP) with NPK (standard cultivation practice), NPK+Straw, and PK fertilizations. Nitrous oxide emission rates were collected twice a week using a closed chamber method. With continuous flooding, nitrogen (N) application increased $N_2O$ emission by 106.6% ($0.64kg\;ha^{-1}$ in NPK) with respect to the PK treatment ($0.31kg\;ha^{-1}$), and straw addition to NPK enhanced 148.3% of seasonal $N_2O$ flux ($0.77kg\;ha^{-1}$ in NPK+Straw). Although seasonal $N_2O$ emission slightly increased by 16.1-42.9% with intermittent irrigation, its seasonal $CH_4$ emission drastically reduced at 43.5-52.8% resulting in a lower GWP at 48.9-58.5% with respect to that of continuously flooded treatments ($4.51Mg\;CO_2\;ha^{-1}$, PK; $7.60Mg\;CO_2\;ha^{-1}$, NPK; $14.55Mg\;CO_2\;ha^{-1}$, NPK+Straw). Rice yield, at similar fertilization with the continuously-flooded rice field, was not affected by intermittent irrigation. Conclusively, intermittent irrigation can be very effective and a rational soil management strategy to mitigate GWP with considering rice productivity in a temperate paddy rice field like Korea.

• 한국해양학회지:바다
• /
• 제22권3호
• /
• pp.135-149
• /
• 2017

미세플라스틱은 5 mm 미만의 플라스틱 조각으로서 의도적으로 제조한 1차 미세플라스틱과 물리 화학적 파쇄나 분해에 의해 만들어진 2차 미세플라스틱으로 나눌 수 있다. 본 연구에서는 인간의 활동으로 인해 미세해진 플라스틱을 발생시키는 배출원을 미세플라스틱의 1차 배출원으로 정의했다. 본 연구에서 미세플라스틱의 1차 배출원을 문헌을 이용하여 정리하고, 각 배출원에서의 발생잠재량을 추정하고자 하였다. 그 결과, 6만 3천~21만 6천 ton/year의 미세플라스틱이 환경으로 유입되는 것으로 나타났다. 그중 선박수송, 타이어분진, 세탁에 의한 배출이 큰 비중을 차지하였다.

• International Journal of Automotive Technology
• /
• 제8권2호
• /
• pp.179-184
• /
• 2007

In this study, the potential use of oxygenated fuels such as ethylene glycol mono-normal butyl ether (EGBE) was investigated in an attempt to reduce the emission of exhaust smoke from diesel engines. Effects of the combustion method on exhaust emission of DI and IDI diesel engines were also examined. Since EGBE is composed of approximately 27.1% oxygen, this is one of several potential oxygenated fuels that could reduce the smoke content of exhaust gas. EGBE blended fuels have been proven to reduce smoke emission remarkably compared to the conventional commercial fuels. The test was conducted with single and four cylinder, four stroke, DI and IDI diesel engines. The study showed that a simultaneous reduction of smoke and NOx emission could be achieved by the combination of oxygenated blend fuels and the cooled EGR method in both DI and IDI diesel engines. It was also found that a reduction rate of exhaust emission in a DI engine was larger than an IDI diesel engine.

• 융복합기술연구소 논문집
• /
• 제4권1호
• /
• pp.15-20
• /
• 2014

Recently, the development of renewable energy sources in Korea has been needed due to climate change. One of powerful alternative energy resources to mitigate emission is to switch conventional fuels to renewable energy, such as bioenergy. In this study, current status of bioenergy conversion technology and its supply in Korea was investigate. Based on theoretical, technical and realizable potential of biomass in Korea, the amount of reduction of green house gases was estimated. The results shown that the contribution of biomass on 2020 reduction target of green house gases emission in power generation was $513,000\;tCO_2/yr$ and utilization ratio of technical potential of biomass was 6.4%. For the effective supply of bioenergy in Korea, more exact estimation of realizable potential of biomass in Korea and stable supply sources are needed.

• 한국세라믹학회지
• /
• 제37권1호
• /
• pp.6-11
• /
• 2000

Electron emission from the Pb(ZrxTi1-x)O3 ferroelectrics by pulsed electric field has been investigated as a function of Zr/Ti ratios such as 35/65, 50/50 and 65/35 below 250kV/cm. Electrons were emitted regardless of the applied field polarity to the rear electrode. When the negative field was applied to the rear electrode, the electron emission charge was more stable. It was proved that the electrons were emitted at the edge of the upper electrode. The emission charge increased in order of 65/35>50/50>35/65. The electron emission characteristics were dependent on the ferroelectric properties such as polarization and coercive field. The emission charge and emission threshold field were affected by the polarization change and the coercive field, respectively. This result explains that the electron emission is a field emission with polarization induced surface potential by a modified Fowler-Nordheim plot of emission charge.

• 한국토양비료학회지
• /
• 제47권5호
• /
• pp.374-380
• /
• 2014

To estimate greenhouse gas (GHG) emission, the inventory of rice cultivation at the farming without agricultural chemicals was established from farmers in Gunsan, Jeonbuk province in 2011~2012. The objectives of this study were to calculate carbon footprint and analyse the major factor of GHGs. To do this, we carried out a sensitivity analysis using the analyzed main factors of GHGs and estimated the mitigation potential of GHGs. Also we suggested agricultural methods to reduce GHGs that can be appled by farmers at this region. At the farming system without agricultural chemicals, carbon footprint of rice production unit of 1 kg was 2.15 kg $CO_2.-eq.kg^{-1}$. Although the amount of carbon dioxide ($CO_2$) emission was the largest among GHGs, methane ($CH_4$) emission had the highest contribution to carbon footprint on rice production system when it was converted to carbon dioxide equivalent ($CO_2-eq.$) multiplied by the global warming potential (GWP). Main source of $CO_2$ emission in the rice farming system without agricultural chemicals was combustion of fossil fuels used by agricultural machinery. Most of the $CH_4$ was emitted during rice cultivation practice and its major emission factor was flooded paddy field in anaerobic condition. Also, most of the $N_2O$ was emitted from rice cultivation process. Major sources of the $N_2O$ emission was application of fertilizer such as compound fertilizer. As a result of sensitivity analysis in energy consumption, diesel had the highest sensitivity among the energy inputs. With the reduction of diesel consumption by 10%, it was estimated that $CO_2$ potential reduction was about 2.0%. With reducing application rate of compound fertilizer by 10%, the potential reduction was calculated that $CO_2$ and $N_2O$ could be reduced by 0.5% and 0.9%, respectively. At the condition of 10% reduction of silicate and compost, $CO_2$ and $CH_4$ could be reduced by 1.5% and 1.6%, respectively. With 8 days more drainage than the ordinary practice, $CH_4$ emission could be reduced by about 4.5%. Drainage and diesel consumption were the main sources having the largest effect on the GHG reduction at the farming system without agricultural chemicals. Based on the above results, we suggest that no-tillage and midsummer drainage could be a method to decrease GHG emissions from rice production system.