• 제목/요약/키워드: Marine Environmental Science and technology

검색결과 720건 처리시간 0.047초

Inter-laboratory Comparison of Stable Carbon and Nitrogen Isotopic Composition Data Using Elemental Analyzer-isotope Ratio Mass Spectrometers

  • Kim, Jung-Hyun;Kang, Sujin;Bong, Yeon-Sik;Park, Kwangkyu;Kang, Tae-Woo;Park, Yong-Se;Kim, Dahae;Choi, Seunghyun;Joo, Young Ji;Choi, Bohyung;Nam, Seung-Il;Lee, Sang-Mo;Shin, Kyung-Hoon
    • 환경분석과 독성보건
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    • 제21권4호
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    • pp.229-236
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    • 2018
  • In this study, inter-laboratory comparison was done using elemental analyzer-isotope ratio mass spectrometers (EA-IRMSs) to determine carbon and nitrogen contents as well as stable carbon and nitrogen isotopic compositions (${\delta}^{13}C$ and ${\delta}^{15}N$) of five environmental samples containing lake and marine sediments, higher plant leaves, and fish muscle, and one organic analytical standard (Protein (Casein) Standard OAS). Five national laboratories participated in this comparison study, and each laboratory analyzed all five samples and the analytical standard. Results showed that variations in total organic carbon (TOC) and total nitrogen (TN) contents as well as ${\delta}^{13}C_{TOC}$ and ${\delta}^{15}N_{TN}$ values among the laboratories were large compared to the analytical uncertainties. The results highlighted the inhomogeneity of the test samples and thus, the need to select suitable standard reference materials for future inter-laboratory studies. Further inter-laboratory comparison exercises could promote good measurement practices in the acquisition of stable carbon and nitrogen isotopic composition data.

Antimicrobial effect of chitosan oligosaccharides, prepared under ultrafiltration membrane bioreactor, against pathogenic bacteria causing flounder fish diseases in aquacultural farm

  • Heo, Moon-Soo;Jeon, You-Jin;Lee, Ki-Wan;Song, Choon-Bok;Lee, Jehee;Yeo, In-Kyo;Yang, Byung-Gyoo;Kim, Se-Kwon
    • 한국어업기술학회:학술대회논문집
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    • 한국어업기술학회 2001년도 추계 수산관련학회 공동학술대회발표요지집
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    • pp.145-146
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    • 2001
  • Despite a variety of development in fish farming during the last decades, fish diseases by bacteria, virus, and parasites are still major problems in aquaculture. Aquaculture of Hounder fish is widely performed around Korea as well as Jeju island, due to relatively stable seed production, short farming period, and a higher value in market. However, intensive feeding and environmental pollution in aquacutural farm act as a great limiting factor in economic aspect. (omitted)

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하수처리수 재이용에 따른 하천과 해역의 환경복원 및 수질관리 모델링 (Environmental Restoration and Water Quality Management Modeling of Coastal Area by Reuse of Treated Wastewater)

  • 이대인;윤양호;박일흠;이규형;조현서
    • 한국환경과학회지
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    • 제16권4호
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    • pp.505-521
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    • 2007
  • This study estimated response of water duality and pollutant behavior according to the discharge and reuse of treated wastewater by three-dimensional eco-hydrodynamic model, and suggest plan that water quality management and environmental restoration in the coastal area including urban stream of Yeosu, Korea. Dispersions of low-saline water and COD by treated wastewater loads (design facility capacity, about $110,000m^3/d$) were very limited in near of effluent site. Nutrients, however, increase compared to the other water quality factors, especially total nitrogen was very sensitive to input loads. When reuse some of treated wastewater to Yeondeung stream, nitrogen was big influence on estuarine water quality. Although current characteristics of treated wastewater such as discharge and water quality were negligible to the change of marine environment, effluent concentration of COD, TN and TP, especially 40% of TN, are reduced within the allowable pollutant loads for satisfy environmental capacity and recommended water duality criteria. Also, controls of input point/non-point sources to Yeondeung stream and base concentration of pollutants in coastal sea itself are very necessary.

동해 울릉분지에서 대륙사면과 분지 퇴적물의 지화학적 특성에 따른 황산염 환원 비교 (Comparison of Sulfate Reduction Rates Associated with Geochemical Characteristics at the Continental Slope and Basin Sediments in the Ulleung Basin, East Sea)

  • 유옥례;목진숙;김성한;최동림;현정호
    • Ocean and Polar Research
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    • 제32권3호
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    • pp.299-307
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    • 2010
  • In conjunction with geochemical characteristics, rate of sulfate reduction was investigated at two sediment sites in the continental slope and rise (basin) of the Ulleung Basin in the East Sea. Geochemical sediment analysis revealed that the surface sediments of the basin site (D2) were enriched with manganese oxides (348 ${\mu}mol$ $cm^{-3}$) and iron oxides (133 ${\mu}mol$ $cm^{-3}$), whereas total reduced sulfur (TRS) in the solid phase was nearly depleted. Sulfate reduction rates (SRRs) ranged from 20.96 to 92.87 nmol $cm^{-3}$ $d^{-1}$ at the slope site (M1) and from 0.65 to 22.32 nmol $cm^{-3}$ $d^{-1}$ at the basin site (D2). Depth integrated SRR within the top 10 cm depth of the slope site (M1; 5.25 mmol $m^{-2}$ $d^{-1}$) was approximately 6 times higher than that at the basin site (D2; 0.94 mmol $m^{-2}$ $d^{-1}$) despite high organic content (>2.0% dry wt.) in the sediment of both sites. The results indicate that the spatial variations of sulfate reduction are affected by the distribution of manganese oxide and iron oxide-enriched surface sediment of the Ulleung Basin.

전파환경에 따른 안테나패턴 측정(APM) 결과가 고주파 해양레이더의 자료 품질에 미치는 영향 (The Effect of Antenna Pattern Measurement According to Radio Wave Environment on Data Quality of HF Ocean Radar)

  • 김재엽;정다운;이석;송규민
    • Ocean and Polar Research
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    • 제44권4호
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    • pp.287-296
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    • 2022
  • High-frequency (HF) radar measures sea surface currents from the radio waves transmitted and received by antenna on land. Since the data quality of HF radar measurements sensitively depend on the radio wave environment around antenna, Antenna Pattern Measurements (APM) plays an important role in evaluating the accuracy of measured surface currents. In this study, APM was performed by selecting the times when the background noise level around antenna was high and low, and radial data were generated by applying the ideal pattern and measured pattern. The measured antenna pattern for each case was verified with the current velocity data collected by drifters. The radial velocity to which the ideal pattern was applied was not affected by the background noise level around antenna. However, the radial velocity obtained with APM in the period of high background noise was significantly lower in quality than the radial velocity in a low noise environment. It is recomended that APM be carried out in consideration of the radio wave environment around antenna, and that the applied result be compared and verified with the current velocity measurements by drifters. If it is difficult to re-measure APM, we suggest using radial velocity in generating total vector with the ideal pattern through comparative verification, rather than poorly measured patterns, for better data quality.

Admirandus multicavus Belogurov and Belogurova, 1979 (Nematoda, Enoplida, Oncholaimidae), a new record of free-living marine nematode discovered from the intertidal zone of Korea

  • Hyun Soo Rho;Hyo Jin Lee;Heegab Lee
    • 환경생물
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    • 제39권4호
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    • pp.463-470
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    • 2021
  • Admirandus multicavus Belogurov and Belogurova, 1979, a new record of free-living marine nematode species belonging to family Oncholaimidae is reported based on the specimens collected from the intertidal sediments of Korea. Admirandus multicavus is characterized by the following unique characteristics: cephalic setae (1-2 ㎛ long), spicules (71-126 ㎛ long) and gubernaculum (15-31 ㎛ long), midventral preanal supplementary organ, three glandular duct openings of the Demanian system, and stoma length measuring twice the width. A comparative analysis of the biogeographical and ecological characteristics of Admirandus species is presented. DIC (Differential interference contrast) photomicrographs of the species are also provided herein. This report represents the first taxonomic analysis of the genus Admirandus Belogurov and Belogurova, 1979 discovered from the Korean seawaters.