• 한국토양비료학회지
• /
• 제46권6호
• /
• pp.463-468
• /
• 2013

The level of nitrous oxide ($N_2O$), a long-lived greenhouse gas, in atmosphere has increased mainly due to anthropogenic source, especially application of nitrogen fertilizers. Quantifying $N_2O$ emission from agricultural field is essential to develop national inventories of greenhouse gases (GHGs) emission. The objective of the study was to develop emission factor to estimate direct $N_2O$ emission from agricultural field in Gangwon-do, Korea by measuring $N_2O$ emissions from potato (Solanum tuberosum), red pepper (Capsicum annum L.), and Chinese cabbage (Brassica campestris L.) cultivation lands from 2009 to 2012. Accumulated $N_2O$ emission was $1.48{\pm}0.25kg$ $N_2O-N\;ha^{-1}$ for red pepper, $1.27{\pm}0.27kg$ $N_2O-N\;ha^{-1}$ for potato, $1.49{\pm}0.06kg$ $N_2O-N\;ha^{-1}$ for Chinese cabbage cultivated in spring, and $1.14{\pm}0.22kg$ $N_2O-N\;ha^{-1}$ for fall Chinese cabbage. Emission factor of $N_2O$ calculated from accumulated $N_2O$ emission, nitrogen fertilization rate, and background $N_2O$ emission was $0.0051{\pm}0.0016kg$ $N_2O-N\;ha^{-1}$ N for cropland in Gangwon province. More extensive study is deserved to be conducted to develop $N_2O$ emission factor for upland crops in Korea through examining the emission factors from various regions and crops because $N_2O$ emission is influenced by many factors including climate characteristics, soil properties, and agricultural practices.

• 자원ㆍ환경경제연구
• /
• 제32권2호
• /
• pp.127-147
• /
• 2023

본 연구는 정부의 탄소중립 정책 중 하나인 화력발전을 신재생에너지로 대체하는 경우 에 대한 경제적 파급효과를 분석하는 것을 목적으로 한다. 이러한 분석을 위해 화력발전을 신재생에너지로 100% 대체하는 경우를 시나리오 A로 설정하고, 60%로 대체하는 경우를 시나리오 B로 설정한다. 또한 이렇게 화력발전을 신재생에너지로 대체할 때 비용이 발생하게 되는데 현행과 동일한 비용인 경우를 시나리오 1, 현행보다 비용이 120% 증가한 경우를 시나리오 2로 설정한다. 따라서 화력발전을 신재생에너지로 전환할 때 시나리오는 크게 이와 같이 4가지 경우로 정리된다. 화력발전을 신재생에너지로 전환하는 경우, 화력발전의 생산유발계수는 시나리오와 관계없이 현행 수준보다 감소하는 것으로 나타났다. 그러나 화력발전을 신재생에너지로 100% 전환하는 경우 부가가치유발계수와 온실가스배출량 유발계수는 현행 수준보다 감소한 반면 화력발전을 신재생에너지로 60% 대체하는 경우 부가가치유발계수와 온실가스배출량 유발계수는 현행 수준보다 증가했다. 또한 대부분의 업종의 온실가스배출량 유발계수는 감소하는 것으로 나타난 반면 생산유발계수와 부가가치유발계수는 증가하는 것으로 나타났다. 정부 정책의 목적은 화력발전을 신재생에너지로 전환시켜 온실가스배출량을 축소시키는 것이기 때문에 시나리오 화력발전을 신재생에너지로 100% 전환하는 경우가 더 적합한 것으로 보인다. 다만, 이로 인해 일부 업종의 생산유발계수와 부가가치유발계수가 감소하는 부작용이 발생하므로 이를 해결하기 위한 정부의 지원 정책이 필요하다.

• 천문학회보
• /
• 제35권1호
• /
• pp.69.1-69.1
• /
• 2010

IC 443 is famous for its interaction with nearby molecular clouds and intense H2 emission lines in infrared. Therefore, it has been studied extensively for the understanding of molecular shocks. We observed H2 mission lines toward the shock-cloud interaction regions of IC 443, known as clumps B, C, and G. The observations were performed with the InfraRed Camera (IRC) onboard a satellite AKARI over 2.5-5.0 um, where previous space observations, e.g. Infrared Space Observatory (ISO) and Spitzer, do not cover. Our AKARI observations provide spectra of sequential pure-rotational and ro-vibrational H2 emission lines. For the clumps C and G, combining with previous mid-infrared observational results, we found that the H2 level populations show a significant separation between v=0 and v=1 levels; v=1 levels are under-populated than v=0 levels, therefore, the population cannot be described by two temperature LTE model, as many people have analyzed for the shocked H2 gas. We also applied the thermal admixture model, dN(H2; T)~T^(-b) dT, with varying ortho-to-para ratios according to the temperature, to describe the level population, and obtained plausible ranges of the H2 gas density and power-law index b.

• 대한교통학회지
• /
• 제29권5호
• /
• pp.55-65
• /
• 2011

본 연구는 교통부문의 지속가능성 평가를 위한 온실가스 배출량 산정 방법론 별 비교분석을 목적으로 하였다. 배출량 산정 방법론은 UN IPCC에서 제시하였으며 유류판매량을 기본으로 한 하향식 방식(Tier1,2)과 이동원의 속도 및 교통량 자료를 활용한 상향식 방식(Tier 3)이 있다. 방법론에 따른 결과 분석을 위하여 분석 대상지역을 선정하였다. 선정기준은 한국교통연구원에서 수행한 지자체별 지속가능교통 평가결과에 근거하여 지속가능성 1등급 지역 중 하나인 과천시와 7등급 지역인 안성시를 대상으로 분석하였다. Tier 1 방법론을 통해 도출된 온실가스 배출량($CO_2$ 기준)은과천시의 경우 74,813ton/yr, 안성시는 584,125ton/yr로 나타났다. Tier 3 방법론 적용 결과 과천시 91,462ton/yr, 안성시 163,801ton/yr로 나타나 과천시의 경우 Tier 1 방법론보다 22.3% 과대추정 되는 결과가 도출되었다. 반면, 안성시의 경우 Tier 3 방법론을 적용하였을 때 온실가스 배출량이 3.5배가량 줄어드는 결과가 도출되었다. 따라서 본 연구를 통해 온실가스 배출량 산정 방법론에 따라 지속가능교통 지수에 의한 지자체별 등급이 다르게 평가될 수 있다는 것을 확인할 수 있었다.

• 한국대기환경학회지
• /
• 제1권1호
• /
• pp.83-92
• /
• 1985

In odrder to survey the emission level of air pollutants from diesel vehicles, was measured CO, HC, NOx and smoke of 4 types of domestic-use diesel engines under various conditions. The emission of CO, HC and NOx tested by 6-Mode test method and smoke emission by full load test met the permissible vehicle emission standard. Pollutant emission rates of diesel engines were different according to engine operating conditions, that is, engine load and engine speed. Generally, CO and HC was emitted more at low load and NOx at high load but the trend was quite different by the type of engines. In exhaust gas, $NO_2$ portion of NOx emission was high, specially at low speed and low load. The correlation equation between CLD(NOx) and NDIR(NO) method of nitrogen of nitrogen oxides analysis was y = 1.10x - 3.48 (y: CLD method) as a result of 6-mode test.

• International Journal of Automotive Technology
• /
• 제7권4호
• /
• pp.407-413
• /
• 2006

The liquefied petroleum gas(LPG), mixture of propane and butane, has the potential to reduce toxic hydrocarbon emissions and inhibit ozone formation due to its chemical composition. Conventional mixer systems, however, have problems in meeting the future lower emission standards because of the difficulty in controlling air-fuel ratio precisely according to mileage tar accumulation. Liquid Phase LPG injection(LPLi) system has several advantages in more precise fuel metering and higher engine performance than those of the conventional mixer type. On the other hands, leakage problem of LPLi system at the injector tip is a main obstacle for meeting more stringent future emission regulations because these phenomena might cause excessive amount of THC emission during cold and hot restart phase. The main focus of this paper is the development of a leaked fuel recirculation system, which can eliminate the leaked fuel at the intake system with the activated carbon canister. Leaked fuel level was evaluated by using a fast response THC analyzer and gas chromatography. The result shows that THC concentration during cold and hot restart stage decreases by over 60%, and recirculation system is an effective method to meet the SULEV standard of the LPLi engine.

• Spatial Information Research
• /
• 제19권6호
• /
• pp.11-18
• /
• 2011

도시공간은 온실가스배출의 주원인지로 온실가스 저감을 위해서는 도시적 차원의 대책이 무엇보다 필요하다. 본 연구는 도시공간을 조성하는데 있어서 활용할 수 있는 이산화탄소 배출량 산정 모델을 개발하는 것을 목표로 하고 있다. 이를 위해, 첫째로 물리적 규모, 이용현황, 활동강도와 관련된 도시공간 계획요소를 이론고찰을 통해 선정하였다. 둘째, 전력, 도시가스, 지역난방, 석유, 상수도 사용량 자료에 기반한 이산화탄소 배출량을 산정하였다. 셋째, 서울시를 사례연구대상지로 선정하고 도시공간 계획요소와 이산화탄소 배출량 간의 관계분석을 통해 도시공간의 이산화탄소 배출량 산정 모델을 개발하였다. 기후변화에 대응하기 위한 다양한 노력들이 도시공간에서 시도되고 있으나, 도시 전체의 탄소배출량과 같은 총량적 관점의 한계가 있었다. 그러나 본 연구의 도시공간 계획요소에 따른 이산화탄소 배출량 산정 모델은 탄소저감을 위한 도시차원에서의 해결방안으로 활용할 수 있는 국지적 범위에서의 보다 구체적인 모델을 제시할 수 있다는 점에서 기존 연구와의 차별된다.

• 한국분무공학회지
• /
• 제23권4호
• /
• pp.212-220
• /
• 2018

As increase the number of vehicles, the issue of greenhouse gas that was emitted by them became important. As a result, greenhouse gas (GHG) regulations are being strengthened and efforts are being actively made to reduce greenhouse gas emissions in the automotive industry. In the other hand, regulations for harmful emission of vehicles have been reinforced by step. Especially, the lastly applied step, so called Euro 6, not only decreased NOx limit down to half of Euro 5 but also introduced real driving emission limit for NOx and PN. It is a challenge for manufacturers to meet the recent GHG regulation as well as the latest emission regulation. To overcome these regulations a De-NOx after-treatment system is being applied to diesel vehicles that are known emitting the lowest GHG among conventional internal combustion engines. At the time of the introduction of Euro 6 emission standard in Korea, in the domestic fuel economy certification test, some diesel vehicles emitted more $CH_4$ than Euro 5 vehicles. As a result, it was confirmed that LNT-equipped vehicles emitted a high level $CH_4$ and the level exceeded the US emission standard. In order to determine the reason, various prior literature was investigated. However, it was difficult to find a detailed study on the methane increase with LNT. In this paper, to determine whether the characteristics of vehicles equipped with LNT the affects the above issue and other greenhouse gases, 6 passenger cars were tested on several emission test modes and ambient temperatures with a environment chamber chassis dynamometer. 2 cars of these were equipped with LNT only, other 2 cars had SCR only, and LNT + SCR were applied to remaining 2 cars. The test result shown that the vehicles equipped with LNT emitted more $CH_4$ than the vehicles with SCR only. Also, $CH_4$ tended to increase as the higher acceleration of the test mode. However, as the test temperature decreases, $CH_4$ tended to decreased. $CO_2$ was not affected by kinds of De-NOx device but characteristic of the test modes.

• 한국연소학회지
• /
• 제10권1호
• /
• pp.1-6
• /
• 2005

This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressure-swirl nozzle of a small-scale burner. The nozzle has orifice diameters of 0.256 mm and liquid flow rates ranging from 50 to 64 mL/min were selected for the experiments. The furnace temperature distribution along the axial distance, the gas emission such as CO, $CO_2$, NOx, $SO_2$, flue gas temperature, and combustion efficiency were studied. The local furnace and flue gas temperatures decreased with an increase in air velocity. At injection pressures of 1.1 and 1.3 MPa the maximum furnace temperatures occurred closer to the burner exit, at an axial distance of 242 mm from the diffuser tip. The CO and $CO_2$concentrations decreased with an increase in air velocity, but they increased with an increase in injection pressure. The effect of air velocity on NOx was not clearly seen at low injection pressures, but at injection pressure of 1.3 MPa it decreased with an increase in air velocity. The effect of air velocity on $SO_2$ concentration level is not well understood. The combustion efficiency decreased with an increase in air velocity but it increased with an increase in injection pressure. It is recommended that injection pressure less than 0.9 MPa with air velocity not above 8.0 m/s would be suitable for this burner.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 2005년도 동계 학술대회 논문집
• /
• pp.76-82
• /
• 2005

This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressureswirl nozzle of a small-scale burner. The nozzle has orifice diameters of 0.256 mm and liquid flow rates raging from 50 to 64 mL/min were selected for the experiments. The furnace temperature distribution along the axial distance, the gas emission such as CO, $CO_2,\;NOx,\;S0_2,$ flue gas temperature, and combustion efficiency were studied. The local furnace and flue gas temperatures decreased with an increase in air velocity. At injection pressures of 1.1 and 1.3 MPa the maximum furnace temperatures occurred closer to the burner exit, at an axial distance of 242 mm from the diffuser tip. The CO and $CO_2$ concentrations decreased with an increase in air velocity, but they increased with an increase in injection pressure. The effect of air velocity on NOx was not clearly seen at low injection pressures, but at injection pressure of 1.3 MPa it decreased with an increase in air velocity. The effect of air velocity $SO_2$ concentration level is not well understood. The combustion efficiency decreased with an increase in air velocity but it increased with an increase in injection pressure. It is recommended that injection pressure less than 0.9 MPa with air velocity not above 8.0 m/s would be suitable for this burner.