• Title/Summary/Keyword: External Carbon

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Promotion of the Low-carbon Agriculture Certification System (저탄소 농축산물 인증제 활성화 방안에 관한 연구)

  • Lim, Sung-Soo
    • Korean Journal of Organic Agriculture
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    • v.24 no.2
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    • pp.201-219
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    • 2016
  • To internalize climate-related external costs from agricultural production and food consumption Pigou taxes and carbon credits increase private costs for food. Voluntary GHG reduction program for carbon-neutral food can be advantageous over such policy measures since they avoid higher food prices for the poor. The pilot project of low-carbon agriculture certification system is to reduce GHG emissions from agricultural production and enhance the competitiveness of domestic agricultural products. This study examines producers', distributors', and consumers' perceptions of the low-carbon agriculture certification system and analyzes alternatives to promote the low-carbon certificated agricultural products.

Vertically Aligned Carbon Film Synthesized from Magnetically Oriented Polyacetylene using Morphology Retaining Carbonization

  • Goh, Munju;Choi, Yong Mun
    • Carbon letters
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    • v.13 no.4
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    • pp.226-229
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    • 2012
  • Polyacetylene (PA) films with vertically aligned fibril morphology were synthesized in homeotropic nematic liquid crystal (N-LC) solvent by using a magnetic field of 5 Tesla as an external perturbation. Scanning electron microscope (SEM) photographs indicated that the lengths of fibrils from the substrate were $5-35{\mu}m$, depending on polymerization time. Carbonization was carried out using iodine-doped PA film and a morphology-retaining carbonization method. From the SEM results, we confirmed that the vertical morphology of the PA remains unchanged even after carbonization at $800^{\circ}C$. The weight loss of the films due to carbonization at $800^{\circ}C$ is about 20% of the weight of the film before iodine doping. It is expected that vertically aligned carbon might be a precursor for preparing vertical graphite materials, which materials could be useful for electrochemical energy storage and cell electrodes.

Simple one-step synthesis of carbon nanoparticles from aliphatic alcohols and n-hexane by stable solution plasma process

  • Park, Choon-Sang;Kum, Dae Sub;Kim, Jong Cheol;Shin, Jun-Goo;Kim, Hyun-Jin;Jung, Eun Young;Kim, Dong Ha;Kim, Daseulbi;Bae, Gyu Tae;Kim, Jae Young;Shin, Bhum Jae;Tae, Heung-Sik
    • Carbon letters
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    • v.28
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    • pp.31-37
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    • 2018
  • This paper examines a simple one-step and catalyst-free method for synthesizing carbon nanoparticles from aliphatic alcohols and n-hexane with linear molecule formations by using a stable solution plasma process with a bipolar pulse and an external resistor. When the external resistor is adopted, it is observed that the current spikes are dramatically decreased, which induced production of a more stable discharge. Six aliphatic linear alcohols (methanol-hexanol) containing carbon with oxygen sources are studied as possible precursors for the massive production of carbon nanoparticles. Additional study is also carried out with the use of n-hexane containing many carbons without an oxygen source in order to enhance the formation of carbon nanoparticles and to eliminate unwanted oxygen effects. The obtained carbon nanoparticles are characterized with field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy, and Raman spectroscopy. The results show that with increasing carbon ratios in alcohol content, the synthesis rate of carbon nanoparticles is increased, whereas the size of the carbon nanoparticles is decreased. Moreover, the degree of graphitization of the carbon nanoparticles synthesized from 1-hexanol and n-hexane with a high carbon (C)/oxygen (O) ratio and low or no oxygen is observed to be greater than that of the carbon nanoparticles synthesized from the corresponding materials with a low C/O ratio.

Carbon/TiO2 Prepared from Anatase to Pitch and their Photocatalytic Performance

  • Chen, Ming-Liang;Ko, Young-Shin;Oh, Won-Chun
    • Carbon letters
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    • v.8 no.1
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    • pp.6-11
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    • 2007
  • Carbon/$TiO_2$ composites were prepared by $CCl_4$ solvent mixing method with different mixing ratios. Since the carbon layers derived from pitch on the $TiO_2$ particles were porous, the Carbon/$TiO_2$ composite series showed a good adsorptivity and photo decomposition activity. The BET surface area for the carbon layer in the sample increases to increasing with pitch contents. The SEM results present to the characterization of porous texture on the Carbon/$TiO_2$ composite and pitch distributions on the surfaces for all the materials used. From XRD data, a weak and broad carbon peak of graphene with pristine anatase peaks were observed in the X-ray diffraction patterns for the Carbon/$TiO_2$. The EDX spectra show the presence of C, O and S with strong Ti peaks. Most of these samples are richer in carbon and major Ti metal than any other elements. Finally, the excellent photocatalytic activity of Carbon/$TiO_2$ with slope relationship between relative concentration (C/$C_0$) of MB and t could be attributed to the homogeneous coated pitch on the external surface by $CCl_4$ solvent method.

Carbon Fibers for the Repair of External Abdominal Hernias in Bovines, Caprines and Canines: A Review of 18 Clinical Cases

  • Kumar, Naveen;Sharma, A.K.;Gangwar, A.K.;Maiti, S.K.;Gupta, O.P.;Kumar, N.;Mathur, R.B.
    • Carbon letters
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    • v.7 no.2
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    • pp.81-86
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    • 2006
  • During a 3-year period (2001-2004) 18 animals were surgically treated because of abdominal wall defects (hernia). Out of 18 animals 8 were bovines, 5 caprines and 5 canines. In each case the defect was bridged with carbon fibres. Carbon fibres were placed either in simple interrupted pattern or as mattress overlapping pattern. All the cases were successfully treated and no complication was observed up to six months postoperatively.

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In-situ rf treatment of multiwall carbon nanotube with various post techniques for enhanced field emission

  • Ahn, Kyoung-Soo;Kim, Jun-Sik;Kim, Ji-Hoon;Kim, Chae-Ok;Hong, Jin-Pyo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.859-862
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    • 2003
  • Well-aligned multiwall carbon nanotubes (MWCNTs) were prepared at low temperature of 400 $^{\circ}C$ by utilizing a radio frequency plasma-enhanced chemical vapor deposition (rf-PECVD) system. The MWCNTs were treated by an external rf plasma source and an ultra-violet laser in order to modify structural defect of carbon nanotube and to ablate possible contamination on carbon nanotube surface. Structural properties of carbon nanotubes were investigated by using a scanning electron microscopy (SEM), Raman spectroscopy, Fourier transformer Infrared spectroscopy (FTIR) and transmission electron microscope (TEM). In addition, the emission properties of the MWNTs were measured for the application of field emission display (FED) in near future. Various post treatments were found to improve the field emission property of carbon nanotubes.

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Changes in the Economic Feasibility of a Floating Photovoltaics Project due to the Social Cost of Carbon (탄소의 사회적 비용에 따른 수상 태양광 사업의 경제성 변화)

  • Jaejune Lim;Jinsoo Kim
    • New & Renewable Energy
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    • v.20 no.1
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    • pp.26-37
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    • 2024
  • Renewable energy sources play a key role in achieving carbon neutrality and zero net emissions in the power generation sector. Various efforts have been made to support the deployment of renewable energy, particularly solar photovoltaic and wind power, including policies to internalize the external cost of carbon emissions. In this study, we conducted a financial analysis of a 800 MW floating photovoltaic system and compared it with ground solar power generation. Additionally, we conducted a cost-benefit analysis that included the social cost of carbon. The findings showed that the floating photovoltaic project can meet the profitability target through an appropriately designed internalization of the social cost of carbon.

Preparation of Carbon-Coated $TiO_2$ at Different Heat Treatment Temperatures and Their Photoactivity

  • Chen, Ming-Liang;Bae, Jang-Soon;Oh, Won-Chun
    • Carbon letters
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    • v.7 no.4
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    • pp.259-265
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    • 2006
  • Carbon-coated $TiO_2$ was prepared by $CCl_4$ solvent mixing method with the different heat treated temperatures (HTTs). Since the carbon layers derived from pitch on the $TiO_2$ particles were porous, the carbon-coated $TiO_2$ sample series showed a good adsorptivity. The values of BET surface areas measured were shown independently on the HTTs. The surface states by SEM present to the characterization of porous texture on the carbon-coated $TiO_2$ sample and carbon distributions on the surfaces. From XRD data, PT700 and PT750 were shown the X-ray diffraction patterns of the anatase $TiO_2$, but PT800 and PT850 were kept anatase-type structure even after heating at $800^{\circ}C$, though small amount of the rutile-type structure appears. The results of EDX microanalyses were observed for each sample show the spectra corresponding to almost all samples similar to C, O and Ti elements with an increase of HTTs. Finally, the excellent photoactivity of carbon-coated $TiO_2$ (especially, PT700 and PT750) could be attributed to the homogeneous coated carbon on the external surface and the structural anatase phase.

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Analysis of the Types of External Wall and Roof Structure Layer Composition of CLT Building (CLT 건축물의 외벽 및 지붕 구조체 레이어 구성 유형 분석)

  • Yoo, Dong-Wan;Lee, Tae-Goo
    • Journal of the Korean Institute of Rural Architecture
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    • v.22 no.4
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    • pp.71-78
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    • 2020
  • Today, the whole world is going through a big chaos due to the COVID-19, but paradoxically, the emergence of COVID-19 has been leading to the need for sustainable development, such as Green New Deal that can improve global warming and carbon emissions, and the need for sustainable architecture is growing bigger and bigger in the architectural field as well. The level of CLT buildings in Korea is at a very rudimentary stage, while CLT buildings remedying existing wooden buildings are getting the spotlight among European countries for sustainable architecture. This study was conducted to categorize structure layer compositions of overseas CLT buildings and analyze architectural techniques and materials applied by collecting and analyzing information about CLT structure layer compositions of overseas CLT building-related institutions, companies and cases. When classifying structure layer compositions of foreign CLT buildings depending on the roles of layers. it was revealed that exterior wall structure layers were combined and organized within a sequence of external finishing, ventilation, waterproof, board, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing, sloped roof structure layers were external finishing, ventilation, waterproof, board, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing, flat roof structure layers were external finishing, ventilation, waterproof, planking wood, external insulation, waterproof, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing.

외부 반송이 있는 생물활성탄담체(BACC) 공정에 의한 오수 중 질소${\cdot}$인의 동시 제거

  • Lee, Ho-Gyeong;Gwon, Sin;Jo, Mu-Hwan
    • 한국생물공학회:학술대회논문집
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    • 2000.04a
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    • pp.414-417
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    • 2000
  • BACC(Biological Activated Carbon Cartridge)process is a newly developed biological process to remove organic compounds, nitrogen, and phosphorus with activated carbon granules in iron fixed-frame cartridge type. The largest defect of previous BACC process was denitrification inefficiency. The removal efficiencies of nitrogen and phosphorous with external recycle ratios $100{\sim}200%$ for synthetic wastewater were $69.8{\sim}90.1%$ and $62.18{\sim}91%$, respectively, since the modified BACC process with external recycle overcame the defect of BACC process. When external recycle ratio was increased more than 300%, T-N removal efficiencies were decreased. In the treatment of a real sewage using modified BACC process, $COD_{Cr}$, removal efficiencies were $96.3{\sim}97.5%$ which was similar to those of the previous BACC process. while T-N removal efficiencies was $88.3{\sim}95.7%$ which were superior to those of the previous BACC process.

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