• Title/Summary/Keyword: carbon emission

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Investigation of field emission mechanism of undoped polycrystalline diamond films (도핑되지 않은 다결정 다이아몬드 박막의 전계방출기구 조사)

  • 심재엽;지응준;송기문;백홍구
    • Journal of the Korean Vacuum Society
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    • v.8 no.4A
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    • pp.417-424
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    • 1999
  • In order to investigate field emission mechanism of undoped polycrystalline diamond films, diamond films with different structural properties were deposited by varying positive substrate bias and/or $CH_4$ concentration. When increasing $CH_4$ concentration and positive substrate bias voltage, nondiamond carbon content in diamond films increased. Increase of nondiamond carbon content with increasing substrate voltage is ascribed to increase of substrate and excess generation of $CH_n$ radicals. Field emission properties of undoped polycrystalline diamond films ere significantly enhanced with increasing nondiamond carbon content. For diamond films with a small amount of nondiamond carbon, electrons are emitted through diamond surface while for the films with a large amount of nondiamond carbon, electron emission occurs through diamond bulk as well as surface. From this study, depending on nondiamond carbon content two field emission mechanisms were suggested.

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A Study on the Functional Unit Trend of Carbon Dioxide Emission in the Construction Materials between 2000, 2003 and 2005 (건축재료의 이산화탄소 배출원단위 변화추이연구)

  • Lee, KangHee;Lee, HaShik;Yang, JaeHyuk
    • KIEAE Journal
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    • v.10 no.5
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    • pp.123-129
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    • 2010
  • This study aimed at analyzing the trend of carbon dioxide emission for direct and indirect areas by using inter industry relations table between 2000, 2003 and 2005 in the key building materials and components. Results of this study are as follows; First, the material and components for this study was selected in 20 industries of products such as sand, gravel, cement, concrete articles, rebar, and steel bar. Second, among the 20 selected key building materials, the group with the highest carbon-dioxide emission was shown in ready-mixed concrete, concrete articles, and primary aluminum goods. Third, as a result of analyzing the changes to the units of carbon dioxide emission according to passage of time, the number of items which is changed in such as sustained increase or decrease over time was insignificant in carbon-emission change trend.

RF power dependence on field emission property from carbon thin film grown by PECVD (PECVD에 의해 작성된 탄소계 박막의 전계전자방출특성에 대한 RF power 의존성에 관한 연구)

  • ;;K. Oura
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.519-523
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    • 2000
  • Using plasma-enhanced chemical vapor deposition (PECVD), carbon thin film as electron field emitter were fabricated. These carbon thin film were deposited on Si(100) substrate at several RF power. These film were estimated by raman spectroscopy, scanning electron microscopy, and field emission. The field electron emission property of these carbon thin film was estimated by a diode technique. As the result, we observed that the field emission properties of these films were promoted by higher RF power. These results are explained as change of surface morphology and structural properties of carbon thin film

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Post-Treatment of Printed Carbon Nanotubes for Vertical Alignment

  • Kim, Yong-C.;Sohn, K.H.;Cho, Y.M.;Yoo, Eun-H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.692-695
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    • 2004
  • Fabrication of photosensitive carbon nanotubes paste and its post-treatment has been developed for high resolution with good electron emission uniformity. We report novel post-treatment techniques including rubber-rolling and multiple field emission cycling from which we could improve the field emission properties of printed carbon nanotubes. These techniques would be easily applicable to large area field emission display using paste of carbon nanotubes

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Field emission characteristics of carbon nanfiber bundles

  • Kim, Sung-Hoon
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.14 no.5
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    • pp.211-214
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    • 2004
  • Carbon nanofiber bundles were formed on silicon substrate using microwave plasma-enhanced chemical vapor deposition system. These bundles were vertically well-grown under the high negative bias voltage condition. The bundles were composed of the individual carbon nanofiber having less than 100 nm diameters. Turn-on voltage of the field emission was measured around 0.8 V/$\mu\textrm{m}$. Fowler-Nordheim plot of the measured values confirmed the field emission characteristic of the measured current.

Environmental Impact Assessment for Development Projects Considering Carbon Sink and Sequestration(II) - Focused on a Housing Redevelopment Project - (탄소흡수원을 고려한 개발사업 환경영향평가 방안(II) - 주택 재개발 사업을 중심으로 -)

  • Hwang, Sang Il;Park, Sun Hwan
    • Journal of Environmental Impact Assessment
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    • v.20 no.1
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    • pp.79-87
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    • 2011
  • In this study, we investigated the effect of carbon sequestration and sink on the environmental impact assessment of a housing redevelopment project. Through the case study, we found that the amount of carbon sequestration and sink increased with the increase of the area of park and green space and, furthermore, the amount of carbon emission decreased slightly with implementation of district heating and renewable energy. Therefore, it is necessary for its land use plan to be established to minimize the amount of net carbon emission, taking account of both the amount of present carbon emission and the amount of the future carbon sink, sequestration, and emission.

GIS based Estimation of Carbon Emission for a Local Government Unit (지자체 단위의 GIS기반 탄소발생량 추정)

  • Kim, Tae-Hoon
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.4
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    • pp.81-89
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    • 2011
  • Low-carbon Green Growth is highlighted as the main issue from in and outof Korea. Recently Korean government and local goverment constructed a master plan and related database. Considering this as a starting point the carbon gross emission has become an important factor in the city planning and management of local goverment unit. This research was focused on the analysis of carbon gross emission and the environment of carbon occurrence using statistics and digital forest map for the Gyeonggi-do. Further research need to analysis the carbon absorption using satellite image for periodic database. These database will be available basic data for the policy making.

Evaluating Carbon Dioxide Emission from Cadastral Category based on Tier 3 Approach (Tier 3 방식에 의거한 지목별 온실가스 배출 실태평가)

  • Kim, Dae-Ho;Um, Jung-Sup
    • Spatial Information Research
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    • v.19 no.3
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    • pp.11-22
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    • 2011
  • It is usual for the carbon dioxide emission to be calculated by official energy consumption statistics produced from a number of specialized industrial process such as refinery, power plant etc. The aim of this research was to evaluate potential of cadastral system in monitoring carbon dioxide emitted from land use. An empirical study for a cadastral category was conducted to demonstrate how a on-site measurement can be used to assist in estimating the carbon dioxide emission in terms of land use specific settings. The cadastral category based analysis made it possible to identify area-wide patterns of carbon dioxide emission, which cannot be acquired by traditional Government statistics. It was possible to identify successively increasing trends in the human-related parcels such as housing land while decreasing trends of carbon dioxide in sink parcels(eg. forest). The results indicate that the cadastral parcel could be used not only as a tool to monitor carbon dioxide emission, but also as an evidence to restrict initiation of development activities causing negative influence to carbon dioxide emission such as road construction. As a result, the research findings have established the new concept of "carbon dioxide emission monitoring based on cadastral category", proposed as an initial aim of this paper.

CO2 Emission, Energy Consumption and Economic Development: A Case of Bangladesh

  • Islam, Md. Zahidul;Ahmed, Zaima;Saifullah, Md. Khaled;Huda, Syed Nayeemul;Al-Islam, Shamil M.
    • The Journal of Asian Finance, Economics and Business
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    • v.4 no.4
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    • pp.61-66
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    • 2017
  • Environmental awareness and its relation to the development of economy has garnered increased attention in recent years. Researchers, over the years, have argued that sustainable development warrants for minimizing environmental degradation since one depends on the other. This study analyzes the relationship between environmental degradation (carbon emission taken as proxy for degradation), economic growth, total energy consumption and industrial production index growth in Bangladesh from year 1998 to 2013. This study uses Vector Autoregression (VAR) Model and variance decomposition of VAR to analyze the effect of these variables on carbon emission and vice-versa. The findings of VAR model suggest that industrial production and GDP per capita has significant relationship with carbon emission. Further analysis through variance decomposition shows carbon emission has consistent impact on industrial production over time, whereas, industrial production has high impact on emission in the short run which fades in the long run which is consistent with Environmental Kuznets Curve (EKC) hypothesis. Carbon emission rising along with GDP per capita and at the same time having low impact in the long run on industrial index indicates there may be other sources of pollution introduced with the rise in income of the economy over time.

Atmospheric $Co_2$sequestration by urban greenspace (도시녹지에 의한 대기 $Co_2$의 흡수 -춘천시를 대상으로-)

  • 조현길;윤영활;이기의
    • Journal of the Korean Institute of Landscape Architecture
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    • v.23 no.3
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    • pp.80-93
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    • 1995
  • The purpose of this study was to assess functioni fo urban greenspace to reduce atmospheric CO\sub 2\ concentration. The study quantified carbon storage in urban greenspace and carbon emission by fossil fuel consumptio in Chuncheon. The amount of carbon storage in vegetation by land use type was 0.02kg/$m^2$ for commercial land, 4.36kg/$m^2$ for natural land, and 0.54kg/$m^2$ for the other urban lands. In 1994, total amount of carbon emission by fossil fuel consumption was about 257,358 metric tons, and the per capita carbon emission was 1.4 metric ton. Total amount of carbon storage in vegetation was 42,942 metric tons, approximately 17% of the carbon emission. This study excluded quantification of carbon storage in soils. The role of urban greenspace to sequester atomspheric carbon might be much greater, if a soil greenspace to sequester atmospheric carbon might be much greater, if a soil greenspace to sequester atmospheric carbon might be much greater, if a soil carbon storage is included quantification of carbon storage is included. However, increasing coverage of trees and managing them for healthy growth would not be sufficient for avoiding adverse impacts by future climate change. Additional measures should be followed such as an increase of energy use efficiency and development of substitute energy.

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