• Title/Summary/Keyword: Sea

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Growth of Juvenile Sea Cucumber Apostichopus japonicus in Integrated Culture with Rockfish Sebastes schlegeli or Abalone Haliotis discus hannai (해삼(Apostichopus japonicus)과 전복(Haliotis discus hannai) 또는 해삼과 조피볼락(Sebastes schlegeli)과의 복합양식에 따른 해삼의 성장)

  • Choi, Jin;Lee, Sang-Min
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.47 no.6
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    • pp.796-800
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    • 2014
  • A feeding trial was conducted to investigate the growth and body composition of juvenile sea cucumber Apostichopus japonicus in integrated culture with abalone Haliotis discus hannai or rockfish Sebastes schlegeli. Triplicate groups of sea cucumber averaging $1.2{\pm}0.05g$ were cultured alone or with abalone or rockfish for 12 weeks. Survival of sea cucumber was not affected by co-culturing (P>0.05). Weight gain of sea cucumber cultured with rockfish was significantly higher than that of sea cucumber cultured alone (P<0.05), and did not differ from that of those cultured with abalone (P>0.05). These findings indicate that co-culturing sea cucumber with rockfish effectively improves the growth of sea cucumber.

Pozzolan Activity of Heat-treated Dredged Sea Soil (소성된 항만준설토의 포졸란 반응성 분석)

  • Moon, Hoon;Kim, Ji-Hyun;Lee, Jae-Yong;Chung, Chul-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.43-44
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    • 2016
  • Large amount of dredged sea soil is produced in southeast seashore region in during harbor maintenance. Disposal of dredged sea soil has become difficult due to the environmental regulation. Therefore, disposal of dredged sea soil method is to landfill. But, the capacity of the landfill limit state and if the size of the dredged sea soil is in the range of silt or clay, it cannot be used as reclamation material because ground subsidence occur. In this study, analyzed the pozzolanic activity of dredged sea soil. Analysis of the results showed a pozzolanic activity of dredged sea soil. In addition, incorporation of heat treated dredged sea soil increase both 28 and 56 day compressive strength of mortar specimen.

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Distribution of Suspended Particulate Matters in the East China Sea, Southern Yellow Sea and South Sea of Korea During the Winter Season

  • Choi, Jin-Yong;Kim, Seok-Yun;Kang, Hyo-Jin
    • Journal of the korean society of oceanography
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    • v.39 no.4
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    • pp.212-221
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    • 2004
  • Concentrations of suspended particulate matters (SPM) and their distribution patterns were monitored three times in the East China Sea during the winter season in 1998 and 1999. SPM concentrations showed significant temporal variations controlled by the atmospheric conditions and sea states. In coastal area, SPM values were about 10-20 mg/l in fair weather conditions, but exceeded 100mg/l during the storm periods. Turbid waters were distributed widespread in the continental shelf of the East China Sea and the coastal area of the Korean Peninsula, and these two areas were connected along a NE-SW direction. The distribution patterns of turbid waters were interpreted as representing the transport behavior of suspended matter. Although the primary source of inner shelf mud deposits of Korea seems to be the Korean Peninsula, contribution from the East China Sea to the coastal area of Korea increases especially during the winter season.

Measurement of Sea Ice Thickness in the Arctic Ocean Using an Electromagnetic Induction Instrument (전자기 유도 장비를 이용한 북극해 해빙의 두께측정)

  • Jeong, Seong-Yeob;Lee, Chun-Ju
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.2
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    • pp.189-195
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    • 2012
  • The ice trials of the first Korean icebreaking research vessel "ARAON" were performed at the Arctic Ocean in July-August 2010. The sea ice concentrations of Arctic Ocean were 4/10 to 10/10 and the range of sea ice thickness was roughly 1.0 to 3.5m. In this research, sea ice thickness characteristics at the old ice floes were determined from results of drill hole and apparent conductivity measurements. Especially we measured apparent conductivity using an electromagnetic induction instrument (EM31-MK2) and estimated the sea ice thickness through the empirical equation from Cold Regions Research & Engineering Laboratory, CRREL. The results of estimated sea ice thickness were compared to drill hole measurement results and then, we suggest the new empirical equation to estimate sea ice thickness of single layer type sea ice during the summer season of Arctic Ocean by curve fitting approach to these data.

Antimutagenic and Cancer Cell Growth Inhibitory Effects of Seaweeds

  • Cho, Eun-Ju;Rhee, Sook-Hee;Park, Kun-Young
    • Preventive Nutrition and Food Science
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    • v.2 no.4
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    • pp.348-353
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    • 1997
  • The antimutagenic and cancer cell growth inhibitory effects of methanol extracts from 9 kinds of seaweed were studied in the Ames assay and cell culture systems, respectively. The methanol extracts from the seaweeds of sea lettuce, chlorella, sea tangle, sea mustard, sporophyll of sea mustard, fusiforme, seaweed papulosa, purple laver and ceylon moss showed antimutagenicities against aflatoxin B₁(AFB₁) and N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) in the Salmonella typhimurium TA100. These extracts revealed relatively higher antimutagenicity against AFB₁(indirect mutagen) than MNNG(direct mutagen). Sporophyll of sea mustard and seaweed papulosa exhibited strong antimutagenic activity against AFB₁, and sporophyll of sea mustard, sea tangle and ceylon moss also reduced the mutagenicity induced by MNNG. The sporophyll fo sea mustard exerted the highest antimutagenic activity among the samples treated. The methanol extracts from 9 kinds of seaweed inhibited the growth of two cancer cell lines, AGS human gastric adenocarcinoma cells and HT-29 human colon carcinoma cells. Sea tangle, sea mustard and sporophyll of sea mustard inhibited the growth of cancer cells significantly. These results suggest that various seaweeds show not only antimutagenic activity but also growth inhibitory effect of some cancer cells.

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Study on effective band of advanced microwave scanning radiometer (AMSR) for observing first year sea ice in the Okhotsk Sea by airborne microwave radiometer (AMR)

  • Nakayama, Masashige;Nishio, Fumihiko;Tanikawa, Tomonori;Cho, Kohei;Shimoda, Haruhisa
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.456-461
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    • 1999
  • It is very important for monitoring the interannual variability of sea ice extents in the Okhotsk Sea because the global warming has firstly appeared around the Okhotsk Sea, locating around the southernmost region of sea ice cover in the Northern Hemisphere. In order to develop the sea ice concentration algorithm by microwave sensors onboard satellite, electromagnetic properties of sea ice in the Okhotsk Sea, therefore, were observed by airborne microwave radiometer (AMR), which has the same frequencies as AMSR (Advanced Microwave Scanning Radiometer), ADEOS-II, launching on November, 2000. On this study, it is discussed how to make the image of AMR-EFOV and the video image with nadir angle under flight at the same time, and superimpose the brightness temperature data by AMR-EFOV on the video mosaiced images. For comparing SPOT image, it is clearly that the variation of brightness temperature is small in 89GHz V-pol without the sea ice types and increase at the lower frequency-band.

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Effects of Sources and Levels of Dietary Carbohydrate on Growth and Body Composition of Juvenile Sea Cucumbers, Apostichopus japonicus

  • Choi, Jin;Seo, Joo-Young;Lee, Sang-Min
    • Fisheries and Aquatic Sciences
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    • v.12 no.3
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    • pp.203-208
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    • 2009
  • A factorial feeding trial of different levels of three carbohydrate sources (wheat flour, $\alpha$-potato starch, and sodium alginate) was conducted to determine proper sources and levels of dietary carbohydrate for juvenile sea cucumbers. Three replicate groups of juvenile sea cucumbers (770 mg average weight) were fed the experimental diets once a day for 10 weeks. After feeding trial, survival of sea cucumbers was not significantly different between diets. The body weight of sea cucumbers was significantly (P<0.01) affected by both source and level of dietary carbohydrate, tending to decrease as dietary carbohydrate level increased. Body weight of sea cucumbers fed a 25% wheat flour diet was the highest but was not significantly different from that of sea cucumbers fed diet containing 10% wheat flour with 15% sodium alginate (P>0.05). No significant differences were observed in contents of moisture, crude protein, crude lipid and ash of sea cucumbers among dietary treatments. These results suggest that sea cucumbers utilize wheat flour and sodium alginate more efficiently than they do $\alpha$-potato starch, and that a formulated diet containing 43-60% carbohydrate may be suitable for juvenile sea cucumber culture.

Sea surface circulation and ie variability in the North East Asian Seas by remote sensing (Topex/Poseidon)

  • Yoon, Hong-Joo;Yoon, Yong-Hoon
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.04a
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    • pp.108-111
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    • 2003
  • Altimeter data from the Topex/Poseidon (T/P) were analyzed to study the sea surface circulation and its variability in the North East Asian Seas. Long term averaged T/P sea level time series data where compared with in situ sea level measurements from a float-operated type tide gauge around of south Korea and Japan. Tf data are a large contaminated by 60-day tidal aliasing effect, very near the alias periods of M2 and S2. When this 60-day effect is removed, the data agree well with the tide gauge data with 4.6 cm averaged RMS difference. The T/P derived sea level variability reveals clearly the well-known, strong current-topography such as Kuroshio. The T/P mean sea level of North Pacific (NP) was higher than Yellow Sea (YS) and East Sea (ES). The T/P sea level variability, with strong eddy and meandering, was the largest in eastern part of Japan and this variability was mainly due to the influence of bottom topography in Kuroshio Extension area.

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Improvement Alternative of Korean Environmental Assessment through the EA of the European Union (유럽연합의 EA에 비춰본 한국의 환경평가제도 개선 방안)

  • Kim, Im-Soon;Han, Sang-Wook;Park, Joo-Hyun
    • Journal of Environmental Impact Assessment
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    • v.15 no.2
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    • pp.139-155
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    • 2006
  • The introduction of Strategic Environmental Assessment (SEA) has strengthened and extended the value of Environmental Impact Assessment (EIA) as a fundamental tool for sustainable development. In particular, SEA helps to overcome the limitation of project EIA as a stand alone approach that is applied relatively late in the decision making cycle. SEA is applied to proposals of policy, plan, and/or programme when major alternatives are open. In Korea, similar to SEA, the Prior Environmental Review System (PERS) was introduced to overcome the limitations of the EIA, by checking the environmental impacts on major policy and administrative actions in the early stage of decision making process. SEA appears in various national, regional and international laws. SEA is addressed specifically in the UNECE SEA protocol to the Espoo Convention on Environmental Impact Assessment in a transboundary context, as well as the European Commission SEA Directive (2001/42/EC). SEA is a valuable tool for integrating sustainability decisions into country's policies, plans and programmes. This paper reviews the policy direction for implementation of the SEA and efficient Environmental Assessment (EA) through integration of the PERS and the EIA.

A Laboratory-scale Recirculating Aquaculture System for Sea Cucumber Apostichopus japonicus (소형 순환여과양식시스템에서 어린 해삼(Apostichopus japonicus) 사육)

  • Jeong, U-Cheol;Jin, Feng;Choi, Jong-Kuk;Han, Jong-Cheol;Choi, Byong-Dae;Kang, Seok-Joong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.49 no.3
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    • pp.343-350
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    • 2016
  • The sea cucumber Apostichopus japonicus is a commercially valuable aquaculture species in Korea. Aquaculture species require specific nursery culture conditions to increase survival and growth rates. Sea cucumbers hibernate during the high temperatures of summer and during the low temperatures of winter, and suboptimal temperature conditions decrease sea cucumber growth and survival rates. The natural South Korean environment is very unfavorable for culturing sea cucumber; therefore, developing a recirculating aquaculture system (RAS) capable of breeding and growing sea cucumber year-round is necessary. The aim of this study was to investigate growth performance of juvenile sea cucumber in a RAS. Growth and survival rates of juvenile sea cucumber were high during our 24-week experiment. Sea cucumber survival rates were 87.8-93.3%, and specific growth rates were 0.4689-0.7846.