• Carbon letters
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• 제2권2호
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• pp.113-119
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• 2001

The advanced method for $CO_2$capture is currently one of the most important environmental issues in worldwide and it is therefore necessary to have available technologies, which minimize the discharge of $CO_2$ including Carbon-14 from nuclear facilities into the atmosphere. A key aspect of this work is to provide the technically principal data required to improve a $CO_2$ removal system for the utilization of regenerative sorbent use, specifically include suggestions regarding its modified column design (parallel dual-bed assembly), stop-restart operation and the economic feasibility of sorbent use. The removal performance of soda lime and the effects of relative humidity (RH) and packing bed-depth (BD) on $CO_2$ removal were investigated. In a single-bed, it revealed that the utilization of soda lime for $CO_2$ removal at line velocity of 13 cm/sec and bed depth of 12 cm increased with the increased relative humidity up to 85%. However, in the parallel dual-bed assembly applied with the stop-restart operation, a maximum utilization rate of soda lime for $CO_2$ removal was obtained even at 55% of RH and 8 cm of BD, specifically the utilization rate of soda lime by using this $CO_2$ removal assembly was about two-fold superior to that in a single-bed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.136.2-136.2
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• 2011

A dynamic simulation study on SCR process in GTL process was carried out in order to find optimum operation conditions for pilot plant operation. Optimum operating conditions for SCR synthesis gas process were determined by changing operation variables such as feed temperature and pressure. It was also assumed that physical properties of reaction medium were governed by RKS (Redlich-Kwong-Soave) equation. The effect of temperature and pressure on synthesis gas process $H_2$/CO ratio were mainly examined. Dynamic simulation results were fed back to feed operation condition for optimizing productivity, especially for appropriate condition to FT (Fischer-Tropsch) synthesis unit.

• 대한방사선기술학회지:방사선기술과학
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• 제44권4호
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• pp.359-365
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• 2021

A heavy particle accelerator is a device that accelerates particles using high energy and is used in various fields such as medical and industrial fields as well as research. However, secondary neutrons and particle fragments are generated by the high-energy particle beam, and among them, the neutrons do not have an electric charge and directly interact with the nucleus to cause radiation of the material. Quantitative evaluation of the radioactive material produced in this way is necessary, but there are many difficulties in actual measurement during or after operation. Therefore, this study compared and evaluated the generated radioactive material in the concrete shield for protons and carbon ions of specific energy by using the simulation code FLUKA. For the evaluation of each energy of proton beam and carbon ion, the reliability of the source term was secured within 2% of the relative error with the data of the NASA Space Radiation Laboratory(NSRL), which is an internationally standardized data. In the evaluation, carbon ions exhibited higher neutron flux than protons. Afterwards, in the evaluation of radioactive materials under actual operating conditions for disposal, a large amount of short-lived beta-decay nuclides occurred immediately after the operation was terminated, and in the case of protons with a high beam speed, more radioactive products were generated than carbon ions. At this time, radionuclides of ⁴⁴Sc, ³H and ²²Na were observed at a high rate. In addition, as the cooling time elapsed, the ratio of long-lived nuclides increased. For nonparticulate radionuclides, ³H, ²²Na, and for particulate radionuclides, ⁴⁴Ti, ⁵⁵Fe, ⁶⁰Co, ¹⁵²Eu, and ¹⁵⁴Eu nuclides showed a high ratio. In this study, it is judged that it is possible to use the particle accelerator as basic data for facility maintenance, repair and dismantling through the prediction of radioactive materials in concrete according to the cooling time after operation and termination of operation.

• 한국ITS학회 논문지
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• 제10권5호
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• pp.105-112
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• 2011

교차로에서의 잘못된 신호운영은 신호위반이나 교통지체를 유발하며, 이러한 혼잡에 의한 지체는 대기에 $CO_2$를 증가시키는 원인이 된다. 회전교차로는 이러한 불필요한 지체를 최대한 줄일 수 있는 운영방법중 하나로 본 연구에서는 교차로 운영방법을 신호교차로에서 회전교차로로 전환하였을때 $CO_2$양의 변화를 측정하였다. Intergovernmental Panel on Climate Change(IPCC)는 차량으로 부터의 온실가스 측정을 위해서는 Tier 1 방법을 쓰도록 권유하고 있다. 그러나 이는 차량별 평균주행거리의 데이터를 구하기 힘들기 때문으로 국내에서는 AVI 카메라 등을 이용하여 이러한 데이터를 구할 수 있다. 따라서, 본 연구에서는 차량별 평균주행거리의 데이터를 고려한 Tier 3 방법을 이용하였다. 먼저, 본 연구에서는 두개의 신호교차로를 선택하여 현재의 운영상태와 회전교차로로 변환하였을 때의 지체를 VISSIM을 이용하여 결과값을 분석하였다. 분석결과 복수네거리는 28.6초에서 4.4초로, 한국생명공학연구원앞 삼거리는 156.4초에서 23.6초로 지체가 크게 줄어드는 것으로 나타났다. 또한 $CO_2$의 경우 두개의 교차로에서 총 646.5 톤/년의 양이 줄어드는 것으로 나타났다. 향후에는 한개의 교차로가 아닌 네트웍에서의 테스트와 다양한 교차로에서의 연구가 필요할 것으로 보인다.

• 한국산학기술학회논문지
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• 제14권9호
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• pp.4560-4571
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• 2013

현재 전 세계적으로 도시에서 발생하는 다량의 온실가스로 인한 기후변화 문제가 증가하고 있다. 이러한 기후변화 문제를 해결하기 위해서는 궁극적으로 도시가 저탄소 구조로 변화되어야하며 계획을 수립하는 초기 단계부터 도시구조의 설계 및 운영, 유지 관리단계로 이어지는 도시계획의 전 과정이 통합적으로 고려되어야만 한다. 이에 본 연구는 저탄소 도시계획을 수립하는 초기 단계에서 유지 관리의 전 과정을 평가할 수 있는 방안을 모색하였으며 이를 적용한 사례분석을 통하여 평가결과를 도출하고자 하였다. 이를 위해 단계를 3단계로 구분하고 단계별로 8개 부문, 30개의 세부평가지표를 도출하였으며 이를 바탕으로 국 내외의 선진사례의 적용 실태분석과 관련 전문가들의 설문을 통한 평가결과를 도출하였다. 그 결과 국내의 저탄소 도시계획 수준을 향상시키기 위해서는 도시계획 수립단계에서 정책 및 제도적 장치가 마련되어 지역적 특색에 맞는 계획의 도입이 이루어져야 한다. 또한 설계 및 운영 단계에서는 이를 구체화 시켜 실행할 수 있는 다양한 접근방법이 필요하며, 유지 관리단계에서는 다양한 이해관계자들의 참여와 관리방안이 요구됨을 알 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.188-188
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• 2010

Recently, there has been increased incessantly an interest in research area on energy material for electronic and electric energy generation applications. The proposed material takes an unobtrusive operation into the simple displacing mechanism using chemical impact material. However, this material makes up a radical design, based on the operation of the stoichiometry ratio on the material architecture.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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• pp.452-455
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• 2000

There are increasingly important financial incentives and environmental consideration to improve the effluent quality of wastewater from domestic and industrial users. The activated sludge process is a widely used biological wastewater treatment process. The activated sludge process is complicated due to the many factors such as the variation of influent flowrate and concentration, the complexity of biological reactions and the various operation conditions. Nowadays, not only suspended solids and residual carbon, but also nitrogen and phosphorous concentration of the effluent water must be taken into account for the design and operation of wastewater treatment plants. Also, the effluent quality to be met are more stringent. Therefore, an intelligent control approach is required in order to successful biological nitrogen removal. In this paper, the strategies for dosage of extra carbon in the anoxic zone and DO concentration in the aerobic zone are presented and evaluated through the simulation using the denitrification layout of the IWA simulation benchmark implemented by Matlab$\^$/5.3/Simulink$\^$/3.0. The control strategy to achieve sufficient denitrification rates in an anoxic zone. Methanol is used as an external extra carbon source. The external extra carbon source is required for the nitrogen removal process because nitrogen and organic concentration are fluctuated in the influent flowrate. The dissolved oxygen is calculated by So concentration in the activated sludge model NO.1. The air flowrate of each aerobic reactor is intelligently controlled to achieve the predefined setpoints. Air flowrate is adjusted by the fuzzy logic controller that includes two inputs and one output. The objective function for the optimization procedure is designed to improve effluent quality and reduce the operating cost.

• 토지주택연구
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• 제15권2호
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• pp.19-28
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• 2024

본 연구는 탄소중립건물의 기술적 정의 및 사례 분석을 통해 탄소중립 달성의 잠재성을 분석한다. 2015년 12월 파리 협정에 따라 세계는 평균 기온 상승을 2℃ 이하로 제한하고, 산업화 이전 수준보다 1.5℃로 제한하려는 노력을 추진하기로 합의하였다. 이를 위해 2050년까지 넷제로(net-zero) 상태에 도달해야 하며, 에너지, 토지, 수송 등 광범위한 부문에서 전환이 필요하다. 본 연구는 탄소중립을 달성하기 위한 기술적 접근과 실제 사례를 통해 탄소중립건물의 가능성과 한계를 탐구하며, 이를 통해 미래의 탄소중립 목표 설정에 기여하고자 한다. 특히, 탄소중립 건물의 정의와 그 실현을 위한 다양한 기술적 방안을 소개하고, 이를 실현한 국내외 사례를 분석함으로써 탄소중립 건물의 효과와 실행 가능성을 평가한다. 연구 결과는 탄소중립 건물의 설계, 건설 및 운영에 대한 구체적 가이드라인을 위한 정보를 제공하며, 정책 입안자와 실무자들이 지속 가능한 건축 환경을 조성하는 데 필요한 실질적 정보를 제공한다.

• 한국지열·수열에너지학회논문집
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• 제19권4호
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• pp.18-26
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• 2023

Green-remodeling is to improve the energy performance of existing buildings that have been aged for more than 15 years since completion. In order to achieve the national greenhouse gas emission reduction plan in the building sector, it is necessary to analyze the carbon reduction effect by considering the internal carbon emissions that may occur during green-remodeling of old buildings. This study analyzed the effects of energy reduction and carbon emission reduction when green-remodeling was applied to old health centers constructed in 1992. When applying green-remodeling, the carbon emission reduction effect considered the embodied carbon emission of the improvement items and the carbon emission at the building operation stage. When applying green-remodeling to existing buildings, energy consumption was reduced by 39.3%, and carbon emissions were reduced by 48.9% after 27 years of green-remodeling. In order to reduce carbon emissions, it was important to apply a renewable system as an item to improve the performance of green-remodeling. In particular, it was confirmed that it is very important to consider the photovoltaic system as a top priority for the carbon emission reduction.

• Journal of Advanced Marine Engineering and Technology
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• 제37권7호
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• pp.792-798
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• 2013

In this study, we have carried out measurement for exhaust emissions such as particulate matter (PM), nitrogen oxide and carbon oxide from main engines installed on the training ships, HANBADA and HANNARA, of Korea Maritime University. In particular, we considered the two conditions; at arrivals/departures and at constant speed of about 160 rpm. The result showed that the concentration of PM at the ship arrival was 2.41mg/m3. On the other hand, when the ship is on the navigation condition, the concentration of PM was 1.34 mg/m3. The concentrations of nitrogen oxide and carbon oxide were measured in the range of 1,120~1,600 ppm and 320~1,450 ppm at the arrival and departure at the port. Under constant speed condition, the concentrations of nitrogen oxide and carbon oxide were 913~1,470 ppm and 73~460 ppm, respectively. Generally, the concentrations of exhaust emissions under the arrivals and departures were higher than that of constant speed condition. These results imply that the ship operation skill to prevent a sudden load change of main engine is needed during the arrival or departure. In addition, it means that the difference of exhaust emissions according to navigation conditions has to be considered when the reduction technologies of air pollutants from ships are developed.