• 에너지공학
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• 제20권3호
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• pp.209-215
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• 2011

본 연구에서는 저온 열교환기 효율 향상을 위하여 상온($25^{\circ}C$)과 저온($10^{\circ}C$)에서 탄소나노유체와 산화탄소나 노유체의 열전도도와 점도를 측정하였다. 탄소나노유체는 다중벽 탄소나노튜브에 계면활성제 SDS 100 wt%, 고분자 화합물 PVP 300 wt%를 각각 혼합한 뒤 증류수에 초음파 분산하여 제조하였고, 산화탄소나노유체는 산화 처리된 다중벽 탄소나노튜브를 증류수에 초음파 분산하여 제조하였다. 탄소나노유체의 열전도도는 비정상 열선법을 사용하여 측정하였으며, 점도는 회전형 디지털 점도계를 사용하여 측정하였다. 그 결과 같은 혼합비율과 온도에서 다른 탄소나노유체들 보다 산화탄소나노유체의 열전도도가 가장 높게 측정되었고, 점도는 가장 낮게 측정되었다.

• 한국기후변화학회지
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• 제7권1호
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• pp.85-93
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• 2016

This study the efficiency of greenhouse gas reduction of 'low carbon car collaboration fund' and its alternative 'control of average fuel efficiency and greenhouse gas', and 'improving driving behavior' were analyzed by using LEAP, long term energy analysis model. Total 4 scenarios were set, baseline scenario, without energy-saving activity, 'low carbon car collaboration fund' scenario, 'fuel efficiency improving scenario', and 'improving driving behavior' scenario. The contents of analysis were forecast of energy demand by scenario and application as well as reduction of greenhouse gas emission volume, and the period taken for analysis was every 1 year during 2015~2030. Baseline scenario, greenhouse gas emission volume in 2015 would be 7,935,697 M/T and 13,081,986 M/T in 2030, increased 64.8%. The analysis result was average annual increase rate of 3.4%. The expected average annual increase rate of other scenarios was, 'low carbon car collaboration fund' scenario 1.7%, 'fuel efficiency improving' scenario 3.0%. and 'improving driving behavior' scenario 3.4%. and these were each 1.7%, 0.3%. 0.3% reduce from baseline scenario. The largest reduction was 'low carbon car collaboration fund' scenario, and there after were 'fuel efficiency improving scenario', and 'improving driving behavior' scenario.

• 자원환경지질
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• 제49권1호
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• pp.53-61
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• 2016

현대 사회에서 우리 삶의 생활 방식은 엄청난 에너지를 필요로 하고 있다. 따라서 오늘날 국제사회는 자원 고갈과 에너지 안보 및 지구 온난화 등에 대처하기 위한 에너지 기술 혁명을 진행하고 있다. 즉, 에너지 기술혁명은 저탄소 에너지기술의 개발과 보급으로 나타나고 있다. 국제사회는 미래의 새로운 에너지 패러다임을 위해 진행하고 있는 저탄소 에너지 기술 혁명, 기술개발 현황, 국제사회의 추진 전략, 저탄소 에너지 기술의 부문별 현황과 과제 해결 등을 추진하고 있다. 따라서 국제 사회의 저탄소 에너지 기술 개발현황과 'Web of Science'에 등록된 학술 문헌지에 발표된 저탄소 에너지 자료 (2001~2015년) 검색을 통하여 총 1441편이 확인되었으나 정밀 분석을 통해서 저탄소 에너지에 관련성이 적은 논문을 제외한 결과 총 869편을 분석 대상으로 선정하였다. 저탄소 에너지 기술에 대한 국제적인 공동연구는 영국, 중국, 미국, 네덜란드 및 일본을 중심으로 연구가 이루어졌다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.215-216
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• 2023

As the introduction of new climate system, efforts to change carbon neutrality, efforts to convert carbon neutrality. In Korea, we are setting up carbon emissions through greenhouse gas and energy target management system for business and companies that emit carbon emissions. The construction industry quantitatively predict the carbon emissions, but it is struggling to set up the amount of carbon emissions before construction stage, but it is suffering from lack of data. Therefore, this study was conducted by collecting data on the energy usage amount of carbon emissions according to the energy usage of the construction phenomenon and low-capacity prediction of the construction phenomenon. Through collected data, the average energy usage amount by building users and evaluated the average carbon emissions. It also evaluated the contribution of carbon emissions by energy sources.

• 폴리머
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• 제26권2호
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• pp.270-278
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• 2002

저밀도 2-D 탄소/탄소 복합재료의 저속 충격에 의한 파괴 거동과 첨가제에 따른 충격 에너지 흡수 경향을 연구하였다. 저속 충격시험은 mini tower 낙추 충격 시험기를 이용하였으며, 흑연, 카본블랙, 분쇄탄소섬유를 첨가제로 선택하였다. 흑연의 첨가는 최대하중값을 증가시켰으며, 전체적인 관통이 일어나기까지 응력을 오랫동안 유지시키는 효과를 나타내었다. 특히 9 vol%의 함량에서 흑연이 첨가되지 않은 씨편보다 약 42%의 충격 흡수 개선을 보였다. 약 0.4 J의 낮은 충격에너지에 의한 충격 회수에 따른 실험에서 첨가제가 첨가되지 않은 시편의 경우, 충격에너지는 층간분리에 의해 소모되고, 흑연의 함량이 증가함에 따라 파괴 경향은 시편의 관통으로 변화함을 관찰할 수 있었다.

• Carbon letters
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• 제15권2호
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• pp.89-104
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• 2014

Materials with appropriate surface roughness and low surface energy can form superhydrophobic surfaces, displaying water contact angles greater than $150^{\circ}$. Superhydrophobic carbon-based materials are particularly interesting due to their exceptional physicochemical properties. This review discusses the various techniques used to produce superhydrophobic carbon-based materials such as carbon fibers, carbon nanotubes, graphene, amorphous carbons, etc. Recent advances in emerging fields such as energy, environmental remediation, and thermal management in relation to these materials are also discussed.

• Nuclear Engineering and Technology
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• 제37권4호
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• pp.375-384
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• 2005

To investigate the flow-accelerated corrosion (FAC) dependency of carbon steel (A106 Gr. B) and low-alloy steels (1Cr-1/2Mo, 21/4Cr-1Mo) on pH, orifice distance, and material, experiments were carried out. These experiments were performed using a flow velocity of 4 m/sec (partly 9 m/sec) at pH $8.0\~10.0$ in an oxygen-free aqueous solution re-circulated in an Erosion-Corrosion Test Loop at $130^{\circ}\;{\ldots}$ for 500 hours. The weight loss of the carbon steel specimens appeared to be positively dependent on the flow velocity. That of the carbon and low-alloy steel specimens also showed to be distinguishably dependent on the pH. At pH levels of $8.0\~9.5$ it decreased, but increased from 9.5 to 10.0. Utility water chemistry personnel should carefully consider this kind of pH dependency to control the water system pH to mitigate FAC of the piping system material. The weight loss of the specimens located further from the orifice in the distance range of $6.8\~27.2$ mm was shown to be greater, except for 21/4Cr-1Mo, which showed no orifice distance dependency. Low alloy steel specimens exhibited a factor of two times better resistance to FAC than that of the carbon steel. Based on this kind of FAC dependency of the carbon and low-alloy steels on the orifice distance and material, we conclude that it is necessary to alternate the composition of the secondary piping system material of NPPs, using low-alloy steels, such as 21/4Cr-1Mo, particularly when the system piping has to be replaced.

• 기술사
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• 제42권2호
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• pp.41-48
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• 2009

The Government declared 'Low-Carbon Green Growth' as the new national vision for future development to improve economic growth and quality of life through higher energy efficiency, less energy consumption, wider use of renewable energy, etc. Korea can no longer delay participating in international efforts against global warming by reducing carbon dioxide and other greenhouse gas emissions. Thus low-carbon green growth is not a matter of choice, and it becomes indispensible to sustaining the nation's economic development. The Government is determined to take the initiative in speeding up economic recovery by carrying out the large scale investment projects such as the Korean version of a 'Green New Deal. The 49 trillion-won projects include river improvement, eco-friendly transportation networks, advanced information infrastructure, water resources & dam construction, green cars & clean energy development, etc. which will create nearly one million new jobs over the next four years.

• 한국농촌건축학회논문집
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• 제26권2호
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• pp.1-8
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• 2024

Carbon neutrality refers to a state in which there is no global increase in CO₂ emissions due to human activities. In Korea, for carbon neutrality, green remodeling of existing buildings and customized support tasks for zero energy in new buildings are presented. Germany is showing fundamental changes in energy supply, such as applying renewable energy and higher energy efficiency from nuclear and fossil fuels, which were the existing energy sources. In this study, how Germany establishes policies for carbon neutrality at each state level and the cases applied to increase the energy efficiency of the actually applied residential complexes are analyzed based on this. As a result of the case complex analysis, it was found that the construction direction was being promoted as a zero-energy complex or a carbon-neutral complex by gradually reducing the energy demand in buildings and supplying additional energy with new and renewable energy in the low-energy building distribution in the 1990s. In Germany's ecological complex, energy standards have been strengthened from low-energy architecture to plus-energy architecture over time, and annual heating energy consumption standards and heat transmittance rates for each structure have been achieved at a higher level. The results of this analysis will serve as basic data and derivation of applicable items when planning residential complex development and remodeling of existing buildings for the domestic carbon-neutral goal in the future.

• 신재생에너지
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• 제2권2호
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• pp.75-80
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• 2006

The effective thermal conductivities of $Mm(La_{0.6-0.8})Ni_{4.0}Co_{0.6}Mn_{0.2}Al_{0.2}$ [TL-492] with hydrogen and helium have been examined. Experiment results show that pressure has great influence on effective thermal conductivity in low pressure range [below 0.5 MPa]. And that influence decreases rapidly with increase of gas pressure. The reason is at low pressure, the mean free path of gas becomes greater than effective thickness of gas film which is important to the heat transfer mechanism in this research. And, carbon fibers have been used to try to enhance the poor thermal conductivity of TL-492. Three types of carbon fibers and three mass fractions have been examined and compared. Naturally, the highest effective thermal conductivity has been reached with carbon fiber which has highest thermal conductivity, and highest mass fraction. This method has acquired 4.33 times higher thermal conductivity than pure metal hydrides with quite low quantity of additives, only 0.99 wt% of carbon fiber. This is a good result comparing to other method which can reach higher effective thermal conductivity but needs much higher mass fraction of additives too.