• Title/Summary/Keyword: Ocean environment

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Characteristics of Marine Environment and Algal Blooms in the Inner Bays of the Korean South Coast (한국 남해안 내만의 해양환경과 적조발생의 특징)

  • Lee, Moon-Ock;Kim, Pyeong-Joo;Kwon, Yeong-Ah
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.469-472
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    • 2006
  • The primary objective of this study was to gain insight into the characteristics of algal blooms in relation to the marine environment of the Korean Southern Coast, using more than 22 years worth of data since the first known occurrence of algal blooms. Algal blooms tend to occur when the precipitation or water temperature for a ten-day period prior to the annual bloom exceeds the long-term mean value. There are three notable causative species in six different inner bays, namely Prorocentrum sp., Skeletonema costatum, and Heterosigma akashiwo, and in addition, these three species appeared in different conditions of water temperature and salinity at each region.

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Integrated engineering environment for the process FEED of offshore oil and gas production plants

  • Hwang, Ji-Hyun;Roh, Myung-Il;Lee, Kyu-Yeul
    • Ocean Systems Engineering
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    • v.2 no.1
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    • pp.49-68
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    • 2012
  • In this paper, an offshore process front end engineering design (FEED) method is systematically introduced and reviewed to enable efficient offshore oil and gas production plant engineering. An integrated process engineering environment is also presented for the topside systems of a liquefied natural gas floating production, storage, and offloading (LNG FPSO) unit, based on the concepts and procedures for the process FEED of general offshore production plants. Various activities of the general process FEED scheme are first summarized, and then the offshore process FEED method, which is applicable to all types of offshore oil and gas production plants, is presented. The integrated process engineering environment is presented according to the aforementioned FEED method. Finally, the offshore process FEED method is applied to the topside systems of an LNG FPSO in order to verify the validity and applicability of the FEED method.

Anti-Corrosion Property of Geopolymer Evaluated by an Impressed Current Cathodic Protection Method, Exposed to Marine Environment (염해환경에서 외부전원법에 의한 지오폴리머 시험체 보강철근의 방식특성 평가)

  • Lee, Hae-Seung;Cho, Ggu-Hwan;Park, Dong-Cheon
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.5
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    • pp.397-405
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    • 2014
  • There are many literatures reporting that the service life of re-bars in concrete structures is reduced in the oceanic environment due to chloride attack. To solve this problem, this study used geo-polymer as a mix material for concrete to increase its resistance to salt damage, and the external voltage method, one of the electric methods, is was applied to evaluate the likelihood of re-bars in the oceanic structure being exposed to the extreme salt environment. The items evaluated include the natural potential of re-bars and the corrosion rate. The results of the tests showed that in all of the salt environmental conditions (submerged zone, tidal zone, and crack), the tested materials were remarkably effective compared with ordinary concrete. The corrosion protective property was found not only in the evaluation of the natural potential but also in the evaluation of the corrosion rate, suggesting that the external voltage method can be used stably for geo-polymer RC structures in an extreme salt environment.

Delayed Mode Quality Control of Argo Data and Its Verification in the Pacific Ocean (태평양 Argo 자료의 지연모드 품질관리 및 검증연구)

  • Yang, Joon-Yong;Kang, Seong-Yun;Go, Woo-Jin;Suh, Young-Sang;Seo, Jang-Won;Suk, Moon-Sik
    • Journal of Environmental Science International
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    • v.17 no.12
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    • pp.1353-1361
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    • 2008
  • Quality control of Argo(Array for Real-time Geostrophic Oceanography) data is crucial by reason that salinity measurements are liable to experience some drift and offset due to biofouling, contamination of sensor and wash-out of biocide. The automated Argo real-time quality control has a limit of sorting data quality, so that WJO program is adopted as standardized method of Argo delayed mode quality control (DMQc) in the world that is a precise quality control method. We conducted DMQC on pressure, temperature and salinity measured by Argo floats in the Pacific Ocean including expert evaluation. Particularly, salinity data were corrected using WJO program. 4 salinity profiles of Argo delayed mode were compared with nearby in situ CTD data and other Argo data in deep layer where oceanographic conditions are stable in time and space. The differences of both salinities were lower than target accuracy of Argo. As compared with the difference of salinities before DMQC, those after DMQC decreased by 60-80 percent. Quality of delayed mode salinity data seemed to be improved correcting salinity data suggested by WJO program.

Design of Real Time Monitoring System of Ocean & Harbor Environment Using by Internet (인터넷을 이용한 실시간 해양항만 환경모니터링 시스템의 설계)

  • Seo, Kyu-Woo
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.63-68
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    • 2003
  • For effective conservation of ocean and harbor, long-term and systematic development of the ocean and harbor monitoring system is essential. The monitoring system capable of real-time and accurate data acquisition is necessary for dealing with contamination such as red tide and the flood. This paper introduces the effective and economical real-time harbor environmental monitoring system that utilizes PCS wireless data communication technology. The monitoring system has various functions such as multiple communication, TCP/IP protocol for wireless internet access, system time synchronization, bi-directional communication between the measuring device and the server. The system has been implemented at Shinseondae harbor pier in Busan to validate the systems stability and effectiveness in data acquisition. The acquired real-time ocean and harbor environmental data is expected to have a large effect, when shared by public through internet.

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Annual Variation of Water Qualities in the Shihwa Lake (시화호 수질의 연변화 양상에 대한 연구)

  • Park, Jun-Kun;Kim, Eun-Soo;Cho, Sung-Rok;Kim, Kyung-Tae;Park, Yong-Chul
    • Ocean and Polar Research
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    • v.25 no.4
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    • pp.459-468
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    • 2003
  • Annual variation of water qualities in the Shihwa Lake were observed 18 times from June 1996 to October 2001. We studied at the station of the upper streams and near the water gate of lake. After the flow of the outer seawater through the water gate, the surface salinity in Shihwa Lake increased to the range of 25-30 psu in both stations after October 1998. Due to the declination of the salinity differences between the surface and the bottom water, the pycnocline in which had existed until 1997 has weakened, and made the water column mix vertically. This led to the improvement of anoxic/hypoxic environment at bottom waters after April 1998. However, despite the continuous flow of the outer seawater, the concentrations of chlorophyll-a at surface layer were varied from $2{\mu}g/l\;to\;60{\mu}g/l$, and these values indicated the eutrophication. The following organic matter load was greatly influencing the surface layer's COD concentration. During the rainy season, the salinity at the surface layer to the below 15 psu resulting in stratification between the surface and bottom layer. Organic matters that were provided from the surface layer to the bottom layer due to active primary production in the year exhausted dissolved oxygen at the bottom layer, and the bulks of organic matters at bottom gave rise to hypoxic or anoxic environment. It was observed that the enrichment of ammonia and phosphate were main factors to worsen the water quality of the Shihwa Lake. The results of examining the annual variations in Shiwha Lake through principal component analysis shown that water characteristics in the rainy season were similar with those before input of outer sea water.

Analysis of Gene Expression in Benzo[a]pyrene-exposed Sebastes schlegeli using Differential Display Polymerase Chain Reaction (DD-PCR을 이용한 벤조피렌 노출 조피볼락의 차등 발현 유전자 분석)

  • Yum Seungshic;Woo Seonock;Choi Eunseok;Kim Sojung;Oh Rora;Lee Sukchan;Lee Taek Kyun
    • Environmental Analysis Health and Toxicology
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    • v.20 no.1
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    • pp.67-73
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    • 2005
  • 오염물질의 노출에 의해 발현이 변화되는 유전자의 발굴은 외부환경 자극에 대한 적응이나 반응의 메커니즘을 알아내는뎨 중요한 정보를 제공하며, 오염물질에 반응하는 유전자는 환경오염을 감지하는 분자 마커로 개발될 수 있다. DD-PCR 기법은 차등 발현 유전자들을 발굴해내기 위한 유용한 방법으로 사용되어 왔고, 본 연구는 이 방법을 이용하여 벤조피렌에 반응하는 조피볼락 유전자들의 발굴을 목적으로 진행되었다. 간조직에서 추출한 RNA로부터 벤조피렌의 노출에 의해 발현 양이 달라진 12개의 클론을 발굴하였고, 그 염기서 열을 분석하였다. 또한 벤조피렌의 노출시간을 각각 6, 12, 24시간으로 달리한 조피볼락에서 12개의 클론 중 4개의 클론에 대해 northern blot 분석이 실시되었으며, 이들 모두 노출시간에 따 라 발현양이 증가 또는 감소하는 것이 확인되었다. 본 연구결과는 오염물질의 영향에 의한 유전자들의 발현에 관한 전반적인 지식을 제공하였고, 나아가 환경오염이나 외부 스트레스를 감지해 낼 수 있는 바이오마커의 개발을 위한 첫 단계로서의 정보를 제공할 수 있을 것으로 생각된다.