• Title/Summary/Keyword: low carbon

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A Study on the Low-carbon Urban Regeneration Planning Elements and System in Climate Change Era. (기후변화대응 탄소저감형 도시재생 계획 요소 및 체계에 관한 연구)

  • Choi, Joung-eun;Choi, Joon-Sung;Oh, Deog-Seong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6345-6359
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    • 2015
  • This study aims to clarify the concept of 'Low-carbon urban regeneration', to extract planning elements according to it, and to establish the planning system. In order to extract the elements, matrix analysis was conducted between planning elements of urban regeneration and Low-carbon cities, and the focus group interview(FGI) was used. Derived elements from this process were restructured for the new planning system. In addition, in-depth case analysis was performed to verify the suitability and effects of planning elements and system. The result showed that planning element of Low-carbon urban regeneration can be sorted in 37 elements in 5 categories. In-depth analysis indicated that established planning elements were importantly dealt in cases and played a significant role in urban regeneration and carbon reduction. Also, it showed that those elements had a significant relationship with adaptation and mitigation, the two responding strategies to the climate change. Elements highly contributing to urban regeneration were Urban Structure, Transportation, Policy while elements affecting carbon reduction were Transportation, Green & Blue space, Energy & Material field.

An Investigation on the Technical Background for Carbon-14 Monitoring in Radioactive Effluents (원자력시설의 Carbon-14 방사성유출물에 대한 감시배경의 조사)

  • Kim, Hee-Geun;Kong, Tae-Young;Jeong, Woo-Tae;Kim, Seok-Tae
    • Journal of Radiation Protection and Research
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    • v.34 no.4
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    • pp.195-200
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    • 2009
  • effluents to the environment. The activity of carbon-14, one of the radioactive effluents, in the environment is already high level and its effect on radiation exposure to the public and the environment is insignificant; thus, NPPs did not perform the carbon-14 monitoring in effluents in the past. By the way, effluents of noble gas and particulate radioactive materials originated from nuclear fuels has been continuously reduced due to both the advancement of manufacturing and integrity technology for nuclear fuels and the improvement of operation methods of NPPs. Futhermore, the portion of dose assessment by tritium and carbon-14 to the public has been relatively increased because the lower limit of detection for low-energy beta sources, such as tritium and carbon-14, is low due to the advancement of radiation detection technology. In this paper, the technical background for carbon-14 monitoring in nuclear facilities was investigated using United States technical reports and papers. This paper also reviews whether carbon-14 monitoring is necessary or not based on the investigated documents.

탄소 나노튜브의 나노 모터 응용 해석

  • Lee Jun-Ha
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2006.05a
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    • pp.105-108
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    • 2006
  • We investigated the fluidic gas-driven carbon-nanotube motor based on multi-wall carbon nanotubes and fluidic gas flow. Since the origination of the torque was the friction between the carbon nanotube surface and the fluidic gases, the density and the flow rate of the working gas or liquid were very important for the carbon nanotube motor. Molecular simulation results showed that multi-wall carbon nanotubes with very low rotating energy barriers could be effectively used for fluidic gas-driven carbon-nanotube motors.

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Novel room temperature grown carbon based cathodes for field emission using diamond nano-particle seeding technique

  • Satyanarayana, B.S.;Hiraki, A.
    • Journal of the Korean institute of surface engineering
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    • v.34 no.5
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    • pp.448-454
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    • 2001
  • Low field electron emission from novel carbon based cold cathodes is reported. The cathodes consisted of a layer of nanoseeded diamond and an over layer of nanocluster carbon films. The nanoseeded diamond was first coated on to thesubstrate. The nanocluster carbon films were then deposited on the nanocrystalline diamond coated substrates using the cathodic arc process at room temperature. The heterostructured microcathodes were observed to exhibit electron emission currents of 1 $\mu$A/cm$^2$ at fields as low as 1.5 to 2V/$\mu$m. The effect of the nanoseeded diamond size and concentration and the properties of different nanocluster carbon films on emission characteristics is presented.

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Characteristics of a Carbon Nanotube-based Tunnel Magnetoresistance Device

  • Kim, Jinhee;Woo, Byung-Chill;Kim, Jae-Ryoung;Park, Jong-Wan;So, Hye-Mi;Kim, Ju-Jin
    • Journal of Magnetics
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    • v.7 no.3
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    • pp.98-100
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    • 2002
  • Tunnel magnetoresistive devices using an individual multi-walled carbon nanotube were fabricated and their low-temperature electrical transport propertiers were investigated. With the ferromagnetic Co electrodes, the multi-walled carbon nanotube exhibited hysteretic magnetoresistance curve at low temperatures. Depending on the temperature and the bias current, the magnetoresistance ratio can be as high as 16% at the temperature of 2.2 K. Such high magnetoresistance ratio indicates a long diffusion length of the multi-walled carbon nanotube.

Preparation and Electric Double Layer Capacitance of Mesoporous Carbon

  • Shiraishi, Soshi;Kurihara, Hideyuki;Oya, Asao
    • Carbon letters
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    • v.1 no.3_4
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    • pp.133-137
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    • 2001
  • Mesoporous activated carbon fiber (ACF) was prepared from phenolic resin containing a small amount (0.1 wt %) of organic nickel complex through carbonization and steam activation. Microporous ACF as reference sample was also prepared from phenolic resin without agent. In both cases of the mesoporous ACFs and the microporous ACFs, the electric double layer capacitance of the nonaqueous electrolyte (0.5 M $TEABF_4$/PC or 1.0 M $LiClO_4$/PC) was not proportional to the BET specific surface area. This is owing to the low permeability of nonaqueous electrolyte or the low mobility of ion in narrow micropores. However, the mesoporous ACF showed higher double layer capacitance than the microporous (normal) ACF. This result suggests that the presence of many mesopores promotes the formation of effective double layer or the transfer of ion in the micropore.

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Dilatometry Analysis of Low Carbon Steel considering Transformation Mismatch Plasticity (변태소성을 고려한 저탄소강 상변태의 Dilatometry 해석)

  • Suh D. W.;Oh C. S.;Kim S. J.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.10a
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    • pp.332-335
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    • 2005
  • A model is developed to quantitatively analyze the dilatometry curve of carbon steel for the evaluation of phase fraction during transformation. The effect of anisotropic volume change due to transformation mismatch plasticity as well as carbon enrichment in austenite during the transformation is considered in the developed model. The developed model is applied for the analysis of dilatometry curves of carbon steels. The result shows that considering the anisotropic dilatation is very essential to quantitatively evaluate the phase fraction from the dilatation curve.

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A binder system for low carbon residue and debinding behaviors in injection molding of NdFeB powder (NbFeB 분말사출성형에소 저잔류탄소를 위한 결합제 및 탈지거동)

  • 최준환
    • Journal of Powder Materials
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    • v.6 no.2
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    • pp.132-138
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    • 1999
  • A new binder system and debinding process for low carbon residue in the injection molding of Nd(Fe, Co)B powder are investigated. In the injection molding of magnetic materials, it is demanded to reduce carbon residue which deteriorates their magnetic properties. The binder system developed is composed of polyethylene glycols (PEGs) and polypropylene (PP). PEG was selected as a major binder is component to be extracted in a molecular state by solvent extraction in ethanol, which step would leave no residue. PP was selected as a minor binder component to be subsequently removed by thermolysis which step would leave carbon residue. The behaviors of solvent extraction with the variations of PEG molecular weight, temperature, and time were examined. The dependency of residual carbon content on thermolysis atmosphere was also studied. Opened pore channels introduced in a green body by the solvent extraction and microstructures of the sintered magnets were observed using SEM.

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Fabrication of a Porous Carbon Surface Using Ethanol Vapor Treatment (에탄올 증기 처리를 통한 다공성 탄소 표면 제작)

  • Im, Doyeon;Kim, Geon Hwee;An, Taechang
    • Journal of Sensor Science and Technology
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    • v.31 no.4
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    • pp.244-248
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    • 2022
  • Recently, several studies on the development of superhydrophobic surfaces using various nano-sized carbon-based materials have been conducted. The superhydrophobic surfaces developed using carbon soot have advantages such as low processing cost and remarkable physical and chemical properties. However, their durability is low. To address this problem, in this study, a superhydrophobic surface with high durability and a multilayer structure was fabricated using ethanol vapor treatment. Candle soot was deposited on an aluminum substrate coated with paraffin wax, and a micro-nano multilayer structure with a size of several micrometers was fabricated via ethanol vapor treatment. The fabricated superhydrophobic surface was confirmed to have a contact angle of at least 156° and high durability. Finally, it was confirmed that ethanol vapor not only changed the nanostructure of carbon but also affected the durability of the structure.

Oxygen Barrier Coating with Carbon Interlayer on Polypropylene

  • Kim, Seong-Jin;Song, Eun-Gyeong;Jo, Gyeong-Sik;Yun, Tae-Gyeong;Mun, Myeong-Un;Lee, Gwang-Ryeol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.210-210
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    • 2012
  • Gas barrier coating from dense thin film deposition has been one of the important applications such as food-packaging and organic display. Especially for food-packaging, plastic container has been widely used due to its low price and high through-put in mass production. However, the plastic container with low surface energy like polypropylene (PP) has been limited to apply gas barrier coating. That is because a gas barrier coating could not adhere to PP due to its too low surface energy and high porosity of PP. In this research, we applied carbon coating consisting of Si and O as an interlayer between silicon oxide (SiOx) and PP. A carbon layer was found to provide better adhesion, which was experimentally proved by oxygen transmission rate (OTR) and SEM images. However, we also found that there is a limitation in the maximum thickness of a carbon layer and SiOx film due to their high stress level. For this conflict, we obtain the optimal thickness of a carbon layer and SiOx film showing optimal gas barrier property.

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