• 제목/요약/키워드: environmental challenge

검색결과 375건 처리시간 0.046초

돌말류 분석 자료 정도 관리의 현황 및 전망 (Current Status and Prospects for the Data Quality Control in Terms of Diatom Analysis)

  • 김혜숙;김종성;박진순
    • 한국해양학회지:바다
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    • 제26권3호
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    • pp.238-247
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    • 2021
  • 돌말류는 미세조류의 일종으로서 담수 및 해양의 여러 다양한 환경의 수생태계에서 가장 중요한 1차 생산자 중 하나이다. 환경을 대표할 수 있는 생물 지표로서 널리 이용되고 있으며, 여러 지역에서 서로 다른 과학자들에 의한 연구 결과들이 과학적 통일성과 객관성을 갖추도록 하기 위해서는 돌말류 분석 자료의 정도 관리가 매우 중요하다. 현재 돌말류 분석은 형태적인 특징으로 분류하는 형태 기반의 분석과 DNA 서열로 종을 식별하는 DNA 바코드 분석이 사용되고 있다. 형태학 기반의 돌말류 분류는 분석 자료를 해석하는 분류학자들 간의 일관된 종 식별이 요구되는 한편 분자 분류 기반의 돌말류 분류는 신뢰성 있는 참조데이터가 필수적이다. 본 논문에서는 돌말류 분석 자료 정도관리의 국내외 현황을 우선 살펴보았으며, 그에 기반하여 국내 돌말류 분석 자료의 정도 관리에 대한 의견을 또한 제안하였다.

Analysis of the Stress Effects of Endocrine Disrupting Chemicals (EDCs) on Escherichia coli

  • Kim, Yeon-Seok;Min, Ji-Ho;Hong, Han-Na;Park, Ji-Hyun;Park, Kyeong-Seo;Gu, Man-Bock
    • Journal of Microbiology and Biotechnology
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    • 제17권8호
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    • pp.1390-1393
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    • 2007
  • In this study, three of the representative EDCs, $17{\beta}$-estradiol, bisphenol A, and styrene, were employed to find their mode of toxic actions in E. coli. To accomplish this, four different stress response genes, recA, katG, fabA, and grpE genes, were used as a representative for DNA, oxidative, membrane, or protein damage, respectively. The expression levels of these four genes were quantified using a real-time RT-PCR after challenge with three different EDCs individually. Bisphenol A and styrene caused high-level expression of recA and katG genes, respectively, whereas $17{\beta}$-estradiol made no significant changes in expression of any of those genes. These results lead to the classification of the mode of toxic actions of EDCs on E. coli.

Decentralized civil structural control using real-time wireless sensing and embedded computing

  • Wang, Yang;Swartz, R. Andrew;Lynch, Jerome P.;Law, Kincho H.;Lu, Kung-Chun;Loh, Chin-Hsiung
    • Smart Structures and Systems
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    • 제3권3호
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    • pp.321-340
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    • 2007
  • Structural control technologies have attracted great interest from the earthquake engineering community over the last few decades as an effective method of reducing undesired structural responses. Traditional structural control systems employ large quantities of cables to connect structural sensors, actuators, and controllers into one integrated system. To reduce the high-costs associated with labor-intensive installations, wireless communication can serve as an alternative real-time communication link between the nodes of a control system. A prototype wireless structural sensing and control system has been physically implemented and its performance verified in large-scale shake table tests. This paper introduces the design of this prototype system and investigates the feasibility of employing decentralized and partially decentralized control strategies to mitigate the challenge of communication latencies associated with wireless sensor networks. Closed-loop feedback control algorithms are embedded within the wireless sensor prototypes allowing them to serve as controllers in the control system. To validate the embedment of control algorithms, a 3-story half-scale steel structure is employed with magnetorheological (MR) dampers installed on each floor. Both numerical simulation and experimental results show that decentralized control solutions can be very effective in attaining the optimal performance of the wireless control system.

Antibody-secreting macrophages generated using CpG-free plasmid eliminate tumor cells through antibody-dependent cellular phagocytosis

  • Cha, Eun Bi;Shin, Keun Koo;Seo, Jinho;Oh, Doo-Byoung
    • BMB Reports
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    • 제53권8호
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    • pp.442-447
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    • 2020
  • The non-viral delivery of genes into macrophages, known as hard-to-transfect cells, is a challenge. In this study, the microporation of a CpG-free and small plasmid (pCGfd-GFP) showed high transfection efficiency, sustainable transgene expression, and good cell viability in the transfections of Raw 264.7 and primary bone marrow-derived macrophages. The non-viral method using the pCGfd vector encoding anti-EGFR single-chain Fv fused with Fc (scFv-Fc) generated the macrophages secreting anti-EGFR scFv-Fc. These macrophages effectively phagocytized tumor cells expressing EGFR through the antibody-dependent mechanism, as was proved by experiments using EGFR-knockout tumor cells. Finally, peri-tumoral injections of anti-EGFR scFv-Fc-secreting macrophages were shown to inhibit tumor growth in the xenograft mouse model.

주석-납 기반 페로브스카이트 고농도 전구체 용액을 이용한 광전류 향상 연구 (Study for Improved Photocurrent via High Concentrated Tin-lead Perovskite Precursor Solution)

  • 홍효진;이승민;임정민;노준홍
    • Current Photovoltaic Research
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    • 제11권3호
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    • pp.96-102
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    • 2023
  • Sn-Pb narrow-bandgap perovskite solar cells, which is a light-harvesting layer thicker than 1.3 micrometers, is needed to enhance the low photocurrent. The fabrication of such a thick film through solution processing is a key challenge. Here, we studied and characterized the film by using a precursor solution of increased concentration, comparing it with the universally used 1-micrometer Sn-Pb perovskite film. The increase in molar concentration clearly induced thickness enhancement, but we observed that it also created numerous voids at the interface with bottom charge transporting layer. We hypothesized that these voids might hinder the increase in photocurrent associated with thickness enhancement. By introducing methylammonium chloride (MACl), we successfully fabricated Sn-Pb perovskite film with a thickness of 1.3 micrometer and no voids. Void-controlled Sn-Pb perovskite solar cells not only demonstrated superior short-circuit current density compared to those with voids but also operated smoothly under light exposure.

Correlation Analysis of Atmospheric Pollutants and Meteorological Factors Based on Environmental Big Data

  • Chao, Chen;Min, Byung-Won
    • International Journal of Contents
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    • 제18권1호
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    • pp.17-26
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    • 2022
  • With the acceleration of urbanization and industrialization, air pollution has become increasingly serious, and the pollution control situation is not optimistic. Climate change has become a major global challenge faced by mankind. To actively respond to climate change, China has proposed carbon peak and carbon neutral goals. However, atmospheric pollutants and meteorological factors that affect air quality are complex and changeable, and the complex relationship and correlation between them must be further clarified. This paper uses China's 2013-2018 high-resolution air pollution reanalysis open data set, as well as statistical methods of the Pearson Correlation Coefficient (PCC) to calculate and visualize the design and analysis of environmental monitoring big data, which is intuitive and it quickly demonstrated the correlation between pollutants and meteorological factors in the temporal and spatial sequence, and provided convenience for environmental management departments to use air quality routine monitoring data to enable dynamic decision-making, and promote global climate governance. The experimental results show that, apart from ozone, which is negatively correlated, the other pollutants are positively correlated; meteorological factors have a greater impact on pollutants, temperature and pollutants are negatively correlated, air pressure is positively correlated, and the correlation between humidity is insignificant. The wind speed has a significant negative correlation with the six pollutants, which has a greater impact on the diffusion of pollutants.

Flood Risk Management for Weirs: Integrated Application of Artificial Intelligence and RESCON Modelling for Maintaining Reservoir Safety

  • Idrees, Muhammad Bilal;Kim, Dongwook;Lee, Jin-Young;Kim, Tae-Woong
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2020년도 학술발표회
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    • pp.167-167
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    • 2020
  • Annual sediment deposition in reservoirs behind weirs poses flood risk, while its accurate prediction remains a challenge. Sediment management by hydraulic flushing is an effective method to maintain reservoir storage. In this study, an integrated approach to predict sediment inflow and sediment flushing simulation in reservoirs is presented. The annual sediment inflow prediction was carried out with Artificial Neural Networks (ANN) modelling. RESCON model was applied for quantification of sediment flushing feasibility criteria. The integrated approach was applied on Sangju Weir and also on estuary of Nakdong River (NREB). The mean annual sediment inflow predicted at Sangju Weir and NREB was 400,000 ㎥ and 170,000 ㎥, respectively. The sediment characteristics gathered were used to setup RESCON model and sediment balance ratio (SBR) and long term capacity ratio (LTCR) were used as flushing efficiency indicators. For Sangju Weir, the flushing discharge, Qf = 140 ㎥/s with a drawdown of 5 m, and flushing duration, Tf = 10 days was necessary for efficient flushing. At NREB site, the parameters for efficient flushing were Qf = 80 ㎥/s, Tf = 5 days, N = 1, Elf = 2.24 m. The hydraulic flushing was concluded feasible for sediment management at both Sangju Weir and NREB.

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백굴채가 마우스의 세포성 및 체액성 면역반응에 미치는 영향 (The Effects of Chelidonii Herba Extract on the Cell Mediate and Humoral Immune Responses in Mice)

  • 박지영;김남중
    • 한국환경보건학회지
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    • 제31권1호
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    • pp.66-72
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    • 2005
  • The effects of Chelidonii Herba on the cell mediate and humoral immune responses were investigated in ICR mice. ICR mice received intraperitoneal injection of methanol extracts (ether fraction, buthanol fraction, water fraction) for 5 days before sensitization. The change of body weight (%), the organ weight ratio (%), the numbers of RBC and WBC, the ear swelling by dinitrofluorobenzene, the titers of hemagglutination (HA) and hemolysin (HY) to SRBC were determined. The results were as follows; 1. The change of body weight (%) showed a tendency of increasing generally. 2. The weight of spleen (%) revealed decreasing but that of thymus revealed increasing. 3. Ear swelling was maxium at 48 hours after challenge and was significantly decreased in the groups treated with Ether, Buthanol and Water. 4. The numbers of RBC and WBC were decreased generally. 5. HA and HY titers were decreased significantly.

An Examination Performed to Identify the Causative Agent of Crusian Carp (Carassius carassius) Mass Mortality in Jinyangho

  • Shin, Gee-Wook;Lee, Hu-Jang;Jung, Tae-Sung
    • 한국환경보건학회지
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    • 제29권4호
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    • pp.1-3
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    • 2003
  • Jinyangho is a natural water supply source of tap water in west Gyeongnam area, but mass mortality of crusian carp occurred during the time of temperature rise in spring. Examinations on diseased fishes were able to isolate four bacteria isolates and then identified the bacteria as a member of Aeromonas sp. Challenge experiment with mirror carp (Gyrinus carpiospecilaris) was proved the virulence, the isolates were in turn believed as the causative agent of mass mortality in Jinyangho.

북한 상하수도 인프라 재구축: 현황과 전망 (Reconstruction of North Korean Water Infrastructure: Present Status and Future Challenge)

  • 윤주환
    • 한국물환경학회지
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    • 제24권6호
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    • pp.641-650
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    • 2008
  • This paper reviews the infrastructure of the water supply and sewerage system in North Korea. North Korean has similar legal protection to preserve water environment that can be seen in Republic of Korea, but North Korean regulations seemed lack of detailed measures. The critical pollution problems of rivers and lakes in the northern part of peninsula is mainly due to the lack of sewage collection system and poor treatment works. It has been estimated that less than 20% of sewers are connected to the wastewater treatment plants. Although the availability of water resources seemed sufficient, North Koreans suffer the lack of the drinking water supply which needs an urgent attention. Based on the analysis, it has been suggested that the reconstruction of North Korean water and sewage infrastructure needs at least 17.5 trillion Korean Won.