• 제목/요약/키워드: NEE

검색결과 126건 처리시간 0.023초

Can $CO_2$ concentration at one level of eddy covariance measurement be used to estimate storage term over forest\ulcorner

  • Choi, Tae-Jin;Chae, Nam-Yi;Kim, Joon;Lim, Jong-Hwan
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2003년도 International Symposium on Clean Environment
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    • pp.47-50
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    • 2003
  • $CO_2$ concentration profile was measured to investigate whether $CO_2$ concentration at one level (i.e., eddy covariance measurement level) can be used to estimate storage term without significant uncertainty at broadleaf deciduous forest at Kwangneung experiment forest in Korea. Based on t-test with significance level of 5%, there was no statistical difference between storage term from one-level $CO_2$ concentration and one from $CO_2$ profile measurement. Storage term constitutes on average 5% of half hourly net ecosystem exchange (NEE) even at unstable stability (i.e., well mixed condition), indicating that storage term should be considered even at daytime, which is sometimes neglected.

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항공자력의 Analytical 이상을 이용한 의송소분지의 지구조 연구 (Geologica Structure of the Euiseong Sub-basin by Anlaytic Aeromagentic Anomaly Data)

  • 김원균
    • 자원환경지질
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    • 제33권3호
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    • pp.229-237
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    • 2000
  • The structure of Euiseong Sub-basin and boundary of sub-basins were examined by analytical aeromagentci anomaly data. Magnetic lineaments have trends of NE-SW, NWW-SEE and NEE-SWW. The NE-SW lineaments in the sedimentary formations and pre-Cretaceous basement are assoicated with the direction of expansion of basin and the lineaments in the volcanic rocks and intrusives indicate the direction of structural weakness ones such as fault, which were major gateways of igneous activities. Euiseong Subbasin is bounded by pre-existing Andong Fault, pre-Cretaceous basement in the west, NE-SW lineament from Jyungsan to Angang, and NW-SE lineament connecting southwestern boundary of Palgongsan Granite and Jeokje Fault. In particular , the NW-SE lineament , which caused upheavel of pre-Cretaceous rocks, on Jeokje Fault is inferred as a boundary between Euiseong and Milyang Sub-basins.

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혁신체제론의 과학기술정책: 기본 관점과 주요 주제 (The Innovation System Approach and Science and Technology Policy)

  • 송위진
    • 기술혁신학회지
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    • 제5권1호
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    • pp.1-15
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    • 2002
  • This study reviews the new Perspectives of science and technology Policy based on "the innovation system ap-proach" . It examines the theories of innovation and the economic rationale of government intervention of the in-novation system approach and compares them with those of traditional nee-classical approach. It also examines the basic theme of science and technology Policy of "the innovation system approach" It argues that the enhancement of innovating capability, the transformation of innovation system coping with changing technological and econom-ic environments, and the policy learning of the government and innovators are very important and peculiar sub-jects of the science and technology Policy based on "the innovation system approach".ovation system approach".uot;.

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Simple Analysis for Interaction between Nanoparticles and Dye-Containing Vesicles as a Biomimetic Cell-Membrane

  • Shin, Sohyang;Umh, Ha Nee;Kim, Younghun
    • Bulletin of the Korean Chemical Society
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    • 제34권1호
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    • pp.231-236
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    • 2013
  • Some cytotoxicity studies for the interpretation of the interaction between nanoparticles and cells are non-mechanistic and time-consuming. Therefore, non-biological screening methods, which are faster and simpler than in-vivo and in-vitro methods, are required as alternatives to current cytotoxicity tests. Here, we proposed a simple screening method for the analysis of the interaction between several AgNPs (bare-, citrate-, and polyvinylpyrrolidone-coating) and dye-containing vesicles acting as a biomimetic cell-membrane. The interaction between AgNPs and vesicles could be evaluated readily by UV-vis spectra. Absorbance deviation in UV-vis spectra revealed a large attraction between neighboring particles and vesicles. This was confirmed by (Derjagin, Landau, Verwey, and Overbeek) theory and DMF (dark-field microscopy) analysis. This proposed method might be useful for analyzing the cytotoxicity of nanoparticles with cell-membranes instead of in vitro or in vivo cytotoxicity tests.

Bioprospecting of Endophytic Fungi as Promising Anti-MRSA Agents

  • Wei, Yee-Min;Tan, Joo-Shun;Tang, Hock-Wei;Tong, Woei-Yenn;Leong, Chean-Ring;Tan, Wen-Nee
    • Natural Product Sciences
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    • 제28권3호
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    • pp.93-104
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    • 2022
  • Methicillin-resistant Staphylococcus aureus (MRSA) is a serious threat to the global healthcare system. Ineffective and resistance to antibiotic treatments have increased morbidity and mortality rates worldwide. New and effective antibiotics are needed to combat against bacterial resistance. Endophytic fungi are crucial reservoirs of novel bioactive metabolites. In particular, the secondary metabolites show promising therapeutic potential, notably, antibacterial. This review discussed the emerging potential of endophytic fungi as anti-MRSA agents. The ecological sources of endophytic fungi were discussed with the synthesis of bioactive metabolites. The mode of antibacterial actions was elucidated to give a better understanding of the mechanisms involved. This review may serve as an important reference for future discovery and developments of anti-MRSA agents from endophytic fungi.

Potential of Endophytic Diaporthe sp. as a New Source of Bioactive Compounds

  • Nagarajan, Kashvintha;Tong, Woei-Yenn;Leong, Chean-Ring;Tan, Wen-Nee
    • Journal of Microbiology and Biotechnology
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    • 제31권4호
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    • pp.493-500
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    • 2021
  • Endophytic fungi are symbiotically related to plants and spend most of their life cycle within them. In nature, they have a crucial role in plant micro-ecosystem. They are harnessed for their bioactive compounds to counter human health problems and diseases. Endophytic Diaporthe sp. is a widely distributed fungal genus that has garnered much interest within the scientific community. A substantial number of secondary metabolites have been detected from Diaporthe sp. inhabited in various plants. As such, this minireview highlights the potential of Diaporthe sp. as a rich source of bioactive compounds by emphasizing on their diverse chemical entities and potent biological properties. The bioactive compounds produced are of significant importance to act as new lead compounds for drug discovery and development.

Providing End-of-Life Care in the Community: What Are the Challenges in Malaysia?

  • Leong, Yoke Yeng;Hamzah, Ednin;McCarthy, Sylvia;Lim, Zee Nee
    • Journal of Hospice and Palliative Care
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    • 제25권3호
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    • pp.133-137
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    • 2022
  • A 72-year-old woman with metastatic lung cancer to bone and brain and with left external iliac vein thrombosis was under the care of a community palliative care provider. She experienced an acute pain crisis due to acute limb ischemia of the left lower limb. Goals-of-care discussions were held with the patient and her family; she prioritized symptom control and end-of-life care at home. The family and patient were aware of her short prognosis. Her complex pain was managed by the community palliative team, and her family was empowered to give subcutaneous injections. We illustrate a case showing the importance of community health services with palliative care support in providing symptom management and support to patient and family caregivers throughout the course of a life-limiting illness. It also highlights family caregivers' potential psychological distress in delivering subcutaneous injections in terminal care for a patient at home.

A TIME DETERMINATION MODEL INCORPORATING RISK MANAGEMENT BASED ON MALAYSIAN CASE STUDIES

  • Sim Nee Ting;Chung Thing Chong
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.642-648
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    • 2009
  • Determining the total duration for a construction project is an integral part of project management in the construction industry. This is to ensure the project and all its associated activities can be carried out and completed within the time frame stipulated. There are several commonly used scheduling methods and techniques in project management, some of which involves manual calculation while others involve computer software. This paper looks into the various time determination methods, extracting out their differences and similarities. It also seeks to draw out the problems when determining time for projects, especially those encountered of case studies. Based on the results from the case studies, there were delays on certain projects even though time determination had been carried out rigorously prior to the commencement of the projects. This paper seeks to develop a time determination model, which incorporates risk management techniques into the calculations in order to improve the method for time estimation to minimize the chances of project delay.

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Adhatoda visica NEES의 알레로페티 효과 (Allelopathic Potential of Adhtoda vasica NEES)

  • ;;;길봉섭
    • Journal of Plant Biology
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    • 제32권2호
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    • pp.109-119
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    • 1989
  • Adhatoda vasica Nees is a shrubby component of tropical and subtropical vegetation in Pakistan. t harbours relatively few unhealthy associated species in and around its thickets. Aqueous extracts, rain leachates, litter from shoots and soil underneath it invariably reduced germination, early growth, biomass, moisture and chlorophyll contents of Pennisetum americanum, Setaria italica, Zea mays, Brassica campestris and Triticum vulgare in different laboratory expreiments. chromatographic analysis revealed the presence of caffeic, ferulic, vanillic, p-coumaric, p-OH-benzoic, and tannic acids in aqueous extracts. The phytotoxicity was related to the test species used, part assayed and parameter measured. It is suggested that the preclusion of the associated species and the dominance of A. vasica is primarily due to allelopathy. Negative grazing also provides better chances for its establishment.

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RCP 시나리오에 따른 미래 전지구 육상탄소순환 변화 전망 (Future Changes in Global Terrestrial Carbon Cycle under RCP Scenarios)

  • 이철;부경온;홍진규;성현민;허태경;설경희;이조한;조천호
    • 대기
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    • 제24권3호
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    • pp.303-315
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    • 2014
  • HadGEM2-CC 모델에서의 $CO_2$ 농도증가에 대한 RCP 시나리오의 결과는 21세기 말 전 지구 연평균 기온과 강수 증가가 전망되고 이에 따라 식물의 생산량 및 호흡량 증가가 전망된다. 20세기 말 일차생산량(GPP와 NPP), 호흡량, LAI가 21세기 말 기온 증가에 따라 증가하는 점은 기존의 Shao et al. (2013)와 유사하였다. 특히 이전 연구와 유사하게 21세기 말 일차생산량과 호흡량은 고위도보다 열대 저위도 지역에서 증가량이 더 컸다. 기온이 상승하고 강수량이 증가하면서 식생이 자라지 않던 나지 면적이 감소하였고, 이에 따른 식생 면적 증가는 식생의 생산량(GPP, NPP) 증가로 나타났다. 특히, 본 연구에서는 C3 초지, 활엽수의 면적 증가가 뚜렷하였다. 이는 Beck and Goetz (2011)에서 언급한 대로 온난화에 따른 식생 면적 증가가 식생 생산성과 연관되어 $CO_2$ 흡수작용을 강화하는 데 기여할 수 있음을 의미한다. Shao et al. (2013)에 따르면 21세기 말 누적 NEE는 증가가 전망되고 이는 특히 열대와 고위도 지역이 주요 흡수원으로 작용하였기 때문으로 그 원인을 설명하였다. 본 연구에서 사용된 HadGEM2-CC에서는 전 지구 평균적으로 NEE 흡수가 증가하는 경향은 동일하게 전망하며, 이는 열대보다는 북반구 고위도지역인 유라시아와 북미 대륙에서 증가한 흡수가 그 원인으로 분석되었다(Fig. 8). 앞서 Mynenl et al. (1997)에 따르면 기온상승에 따라 식생의 광합성활동, 생장시기 길이와 시작시기의 당겨짐을 보고하였다. 본 연구 실험에서도 이와 유사하게 미래에 기온 상승에 따라 식생 성장 기간이 길어지고 LAI도 증가하며 식생 지대가 점차 고위도로 북상할 것을 전망하였다(Figs. 5, 12b). 이에 따라 육상 생태계의 $CO_2$ 흡수량은 20세기 말보다 21세기 말에 증가하였고 우리나라가 속해있는 동아시아지역($90^{\circ}E{\sim}140^{\circ}E$, $20^{\circ}N{\sim}60^{\circ}N$)은 기온, 강수뿐 아니라 $CO_2$ 흡수량도 같은 위도대의 전 지구 동서평균보다 크게 모의되었다. RCPs에 따른 흡수율은 21세기 중반까지는 대기 중 이산화탄소 농도 변화율과 유사한 경향을 보이는데 RCP 8.5에서는 21세기 후반에 흡수 증가율이 감소하며 이는 Liddicoat et al. (2013) 에서 보인것과 유사하다. 하지만 대기 중 $CO_2$의 증가와 식생분포 지역의 확대에도 불구하고 21세기 말 육상생태계의 순생태계흡수량은 크게 증가하지 않음을 확인할 수 있었다. 이는 기온 상승이 크게 일어난 21세기 후반부터 토양 호흡의 급격한 증가로 인하여 육상생태계의 이산화탄소 흡수 능력은 감소한 것에 기인하였다. 향후 본 연구결과의 유의성을 확보하기 위해 다양한 모델의 자료를 추가할 필요가 있다. Shao et al. (2013)에 따르면 미래 탄소 흡수 전망에 있어 전 지구 및 위도별 모의 결과가 모델마다 매우 다양한데 이는 지면생태모형 간의 식생역학, 물리과정의 차이로 해석된다. 미래 육상생태계의 이산화탄소 흡수 능력의 변화와 기후변화를 보다 정확하게 예측하기 위해서는 다른 모델의 자료를 이용한 불확실성을 정량화 하는 것이 필요하며 이는 전 지구 및 지역별 탄소 순환 이해를 높이는 데 기여할 것이다.