• Title, Summary, Keyword: 炭素年代測定

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고대철기의 년대측정 방법개발 - 탄뎀(Tandem)형 가속기 이용해서 측정

  • 한국원자력산업회의
    • Nuclear industry
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    • v.14 no.10
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    • pp.72-76
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    • 1994
  • 이제까지 고대철기의 년대측정은 함께 출토된 토기를 빌어서 이루어져 왔다. 일본에서는 철을 만들 때 열선으로 사용한 목탄에서 흡입된 탄소를 탄뎀형가속기를 이용해 방사선 동위체비 측정방식으로 가속기 질량분석에 위해 철기의 년대를 알아내는 법을 개발했다.

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Radio-Carbon Age Determination by Tandem Accelerator Mass Spectrometry Technique and Its Application To The Korean Sea (탄뎀가속기에 의한 방사성탄소 년대측정과 한국해에의 적용)

  • Suk, Bong-Chool;Toshio Nakamura;Nobuyuki Nakai;Asahiko Taira
    • The Korean Journal of Quaternary Research
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    • v.4 no.1
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    • pp.27-40
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    • 1990
  • $^{14}C$ age dating by AMS (accelerator mass spectrometry) technique was performed on twenty five small sized fossil shells and one peat taken from the sixteen piston cores in the southern and southeastern Korean Sea. AMS technique is available to date only a few milligram of amorphous carbons compare than conventional dating technique. It is described in detail of sample pre-treatment and experimental, and applied to the reconstruction of the sea level changes since the late Pleistocene in the Korean Sea. Dated age ranges from 520$\pm$100 to older than 33,500 years. Sedimentary facies in the study area represents a different environmental set which is affected by sea level fluctuation since the late Pleistocene.

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Is the smog in Seoul deteriorating? (서울의 스모그 현상은 악화되고 있는가?)

  • 김용표;김진영;김영성
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • pp.76-77
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    • 2000
  • 서울의 스모그 현상은 시민이 느끼는 대표적인 대기오염현상이다. 1990년대 들어와, 스모그에 대한 연구 결과가 축적되면서, 스모그는 주로 미세입자에 의해 발생하며, 미세입자 성분 가운데에는 탄소성분과 황산염, 질산염이 스모그 현상에 크게 기여하는 것으로 나타났다. KIST에서는 1980-1993년에 종로구 송월동 옛 기상청 자리에서 측정한 목측 시정자료를 검토하여 (1) 연평균 시정은 10-12 km이며, (2) 연평균시정은 일반적인 예측과는 달리 1990년대 들어와서는 감소하지 않았고, (3) 광학화스모그의 징조가 나타나고 있음을 밝혔다. (중략)

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Simultaneous Measurement and Interecomparison of Criteria Pollutants between Laboratories (대기환경기준 설정항목 실험실간 동시측정 비교)

  • 한진석;김정수;안준영;김창환;김정호;김민영;이민현;조석주;김정영
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • pp.299-301
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    • 2000
  • 대기환경기준 설정항목은 아황산가스를 비롯하여 이산화질소, 일산화탄소, 오존, 총부유먼지(TSP), 미세먼지(PM10), 납 6개항목이며, 이들 오염물질 중 아황산가스와 총부유먼지는 1990년대 급격히 오염도가 개선되는 경향을 보이고 있다. 일산화탄소와 납의 경우에도 환경기준을 대부분의 지역에서 만족하고 있으나 이산화질소와 오존은 개선되는 양상을 보이지 않고 있으며 도리어 오존의 고농도 발생현상은 증가 추세를 보이고 있다. (중략)

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Analysis of Decoupling Phenomenon Between Economic Growth and GHG Emissions: Dynamic Panel Analysis of 63 Countries (1980~2014) (경제성장과 탄소배출량의 탈동조화 현상 분석: 63개국 동태패널분석(1980~2014년))

  • Lim, Hyungwoo;Jo, Ha-hyun
    • Environmental and Resource Economics Review
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    • v.28 no.4
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    • pp.497-526
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    • 2019
  • The importance of "decoupling" to maintain economic growth and reduce greenhouse gases is emerging as the world has been mandated to reduce greenhouse gases since the 2015 Paris Agreement. This study covered 63 countries from 1980 to 2014 and analyzed the main characteristics and causes of decoupling phenomenon between economic growth and carbon emissions. In this study, the degree of decoupling was measured every five years. The analysis found that the decoupling rate of OECD countries and countries with large incomes was high, and that the decoupling phenomenon has accelerated worldwide since the 2000s. However, the degree of decoupling was different depending on the national characteristics. According to the results of dynamic panel model, the growth rate of manufacturing and the proportion of exports hampered decoupling, while the proportion of human capital and renewable energy had a positive effect on decoupling. Also income had a inverse U-shape non-linear effect on decoupling.

Development of 'Carbon Footprint' Concept and Its Utilization Prospects in the Agricultural and Forestry Sector ('탄소발자국' 개념의 발전 과정과 농림 부문에서의 활용 전망)

  • Choi, Sung-Won;Kim, Hakyoung;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.4
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    • pp.358-383
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    • 2015
  • The concept of 'carbon footprint' has been developed as a means of quantifying the specific emissions of the greenhouse gases (GHGs) that cause global warming. Although there are still neither clear definitions of the term nor rules for units or the scope of its estimation, it is broadly accepted that the carbon footprint is the total amount of GHGs, expressed as $CO_2$ equivalents, emitted into the atmosphere directly or indirectly at all processes of the production by an individual or organization. According to the ISO/TS 14067, the carbon footprint of a product is calculated by multiplying the units of activity of processes that emit GHGs by emission factor of the processes, and by summing them up. Based on this, 'carbon labelling' system has been implemented in various ways over the world to provide consumers the opportunities of comparison and choice, and to encourage voluntary activities of producers to reduce GHG emissions. In the agricultural sector, as a judgment basis to help purchaser with ethical consumption, 'low-carbon agricultural and livestock products certification' system is expected to have more utilization value. In this process, the 'cradle to gate' approach (which excludes stages for usage and disposal) is mainly used to set the boundaries of the life cycle assessment for agricultural products. The estimation of carbon footprint for the entire agricultural and forestry sector should take both removals and emissions into account in the "National Greenhouse Gas Inventory Report". The carbon accumulation in the biomass of perennial trees in cropland should be considered also to reduce the total GHG emissions. In order to accomplish this, tower-based flux measurements can be used, which provide a direct quantification of $CO_2$ exchange during the entire life cycle. Carbon footprint information can be combined with other indicators to develop more holistic assessment indicators for sustainable agricultural and forestry ecosystems.

Reviews on the Studies of MTBE Contaminants in Groundwater

  • 이지훈;이진용;천정용;이강근
    • Journal of the Korean Society of Groundwater Environment
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    • v.7 no.1
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    • pp.55-58
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    • 2000
  • Methyl tertiary butyl ether (MTBE) is a gasoline additive that boosts the oxygen content in fuel (an oxygenate), resulting in less air-polluting carbon monoxide being released from vehicle exhaust systems. Then, groundwater contamination problems have been developed in areas where the chemical is used. Common sources of water contamination by MTBE include leaking underground gasoline storage tanks and leaks and spills from above ground fuel storage tanks, etc.. Studies on the chemical and these problems are going on abroad vigorously. These studies should be performed in our country as well more actively. This paper reviews on articles on these studies and focuses on the identification of the chemical as a groundwater contamination source.

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Long-term Trends of the Concentrations of Mass and Chemical Composition in PM2.5 over Seoul (서울시 대기 중 초미세먼지 (PM2.5) 질량과 화학성분 농도의 장기 변동 추이)

  • Han, Sang Hee;Kim, Yong Pyo
    • Journal of Korean Society for Atmospheric Environment
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    • v.31 no.2
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    • pp.143-156
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    • 2015
  • The literature data of the mass concentrations of TSP, $PM_{10}$, and $PM_{2.5}$, and chemical composition of $PM_{2.5}$ (sulfate, nitrate, ammonium, OC, and EC) from 1985 and 2013 at Seoul were collected and the temporal trends were discussed in relation with the policy directions. Generally, the mass concentrations of TSP, $PM_{10}$, and $PM_{2.5}$ at Seoul have showed decreasing trends. However, it is not clear what might be the major reason(s) for the trends. The concentrations of ionic component in $PM_{2.5}$ showed different trends, sulfate being reduced during the 1990s but no trend during the 2000s. The concentrations of nitrate and ammonium were increasing during the 2000s. The concentrations of OC show no apparent trend while that of EC decreased. Further policy directions are suggested based on the temporal trends of the chemical composition in $PM_{2.5}$.

Performance Based Evaluation of Concrete Carbonation from Climate Change Effect on Curing Conditions of Wind Speed and Sunlight Exposure Time (기후변화의 풍속과 일조시간 양생조건에 따른 콘크리트 탄산화 성능중심평가)

  • Kim, Tae-Kyun;Shin, Jae-Ho;Choi, Seung-Jai;Kim, Jang-Ho Jay
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.5
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    • pp.45-55
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    • 2015
  • Currently, extreme weather events such as super typhoon, extreme snowfall, and heat wave are frequently occurring all over the world by natural and human caused factors. After industrial growth in the 1970s, earth's temperature has risen sharply. due to greenhouse effect. Global warming can be attributed to gases emitted from using fossil fuel such as average carbon dioxide, perfluorocarbons, nitrous oxide, and methane. Especially, carbon dioxide has the highest composition of about 90%. in the fossile fuel usage emitted gas. Concrete has excellent durability as a building material climate change. However, due to various of physical and chemical environmental effect such as conditions during its curing process, the performance degradation may occur. Carbon dioxide in the atmosphere causes steel corrosion and durability decreases by lowering the alkalinity of concrete. Therefore, in this study, concrete durability performance with respect to carbonation from curing conditions change due to wind speed and sunshine exposure time. Concrete carbonation experiment are performed. using wind speed (0, 2, 4, 6) m/s and sunlight exposure time (2, 4, 6, 8) hrs. Also, performance based evaluation through the satisfaction curve based on the carbonation depth and carbonation rate test results are performed.