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        검색결과 14

        1.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 제주도에서 규모가 가장 큰 항구인 제주항내 퇴적물을 대상으로 PCBs의 분포특성을 연구하였다. 연구 결과, 제주항 내 표층퇴적물에서 PCBs 화합물의 농도범위는 1.62∼4.45 ng/g dw로 낮은 농도로 분포하고 있었고, PCBs의 동족체 패턴 분석을 보면 제주항은 선박 활동으로 유래되는 고염소화된 CBs(Hexa-CBs 이상)이 주로 분포하였다. 퇴적물에서 PCBs 화합물의 분포에 미치는 유기물의 영향을 평가하기 위하여 퇴적물 내 유기탄소 함량과 PCBs 화합물의 농도와의 상관관계를 검토한 결과, R2이 0.8387로 높게 나타나 유기탄소 함량과 PCBs 농도는 매우 유의한 상관성을 보이는 것을 알 수 있었다. PCBs 화합물의 농도분포와 입자크기와의 관계에서 역질, 사질, 니질로 나누어 조사하였는데 니질의 함량이 증가할수록 PCBs의 농도도 높게 분포하였다. 그리고 연구지역의 표층퇴적물에서 분포하고 있는 PCBs의 농도를 국외에서 적용하고 있는 퇴적물오염기준(sediment quality guidenes, SQGs)의 ERL(effect range-low)과 TEL(Threshold Effects Level) 값과 비교한 결과, 훨씬 낮은 값을 보여 생태독성학적 관점에서 저서생물에 미치는 영향은 미미한 것으로 사료된다.
        4,000원
        2.
        2011.06 KCI 등재 서비스 종료(열람 제한)
        The characteristics of circulation in the coastal area of Jeju Harbor in Korea was examined using the Princeton Ocean Model(POM) with a sigma coordinate system. The result of numerical analysis well corresponded to the observed current data. The velocity at offshore was stronger compared to coastal area during the both period of in maximum flood and maximum ebb of spring tide. According to mean wind velocity, the tidal velocity at the shallow area of Jocheon was slightly increasing during maximum ebb. The effect of wind on the circulation was stronger in shallow area and showed rapid change with depth.
        3.
        2011.05 KCI 등재 서비스 종료(열람 제한)
        Contamination of butyltin compounds (BTs), namely tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), was evaluated in sediments collected inside Jeju Harbor in 2001. The concentrations of BTs in surface sediments were comparable to those in other sites of domestic and foreign countries. The high correlations between BTs in surface (r2 = 0.83~ 0.91) and core (r2 = 0.70~0.79) sediments and the significant correlations between BTs concentrations and the number of incoming and outgoing vessels indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints of vessels etc. and other sources, such as DBT and MBT, could be ignored. The butyltin degradation indices ([DBT] + [MBT]/[TBT]) in surface sediments were in the range of 2.2~3.6 (mean 2.7), indicating that the parent compound, TBT, was inflowed into the surface sediments a long ago, degraded and deposited. The sedimentation age of BTs contaminated core sediments could not estimated because the content of 210Pb activity was nearly all the same and so the sedimentation rate could not obtained.
        4.
        2011.03 KCI 등재 서비스 종료(열람 제한)
        Organotin compounds (OTs), namely butyltins compounds (BTs) and phenyltin compounds (PhTs), were measured in surface and core sediments collected in Jeju harbor. The horizontal and vertical distribution was examined and the relationship between the concentration of OTs and organic matter content and particle size distribution was also studied. BTs were detected in significant concentrations in sediments inside Jeju harbor. PhTs were detected in very low concentrations, compared to BTs. The main species in BTs and PhTs were dibutyltin (DBT) and monobutyltin (MBT), monophenyltin (MPhT), respectively. In the relationships between the concentrations of total BTs and organic carbon content, the significant correlations (r2=0.4898 in surface sediments, r2=0.53 in one core sediments) and no correlation in another core sediments obtained, which is estimated that the distribution of BTs in sediments were affected by several factors, such as their physicochemical properties including organic carbon content, and a tide, etc. In the relationships between the concentrations of total BTs and particle size (mud, sand, and gravel) in sediments, the concentrations of total BTs were higher in the sediments with higher mud content, indicating that higher BTs were distributed with increasing sediments of fine granules.
        5.
        2011.02 KCI 등재 서비스 종료(열람 제한)
        Butyltin compounds in seawater, sediments and organisms inside Jeju Harbor of Jeju Island, Korea, were quantitatively determined to assess the extent of contamination and to evaluate the bioaccumulation in Thais clavigera (gastropod), Liolophura japonica and Cellana nigrolineata. In addition, imposex in T. clavigera was used to assess the sublethal effect of tributyltin compounds and its usage as a specific biomarker for these compounds was also studied. The main species in seawater was tributyltin (TBT) in March and June, monobutyltin (MBT) in August, but in sediments and organisms it was dibutyltin (DBT) and TBT, respectively, irrespective of survey time. TBT, the most toxic to aquatic organisms among BTs, was found at concentrations which were sufficient to have a serous effect on the sensitive organisms upon chronic exposure. The high correlations (r>0.7) between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints and their sources were negligible. The sedimentary organic matters have little influence on the distribution of BTs in marine environment and the lipid content in T. clavigera showed a significant correlation with TBT concentrations. Measurement of imposex T. clavigera was expected to be a very helpful tool for preliminary survey of BTs prior to trace analysis of those.
        6.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        The effect of seasonal wind on the tidal circulation in Jeju harbor was examined by using a numerical shallow water model. A finite element for analyzing shallow water flow is presented. The Galerkin method is employed for spatial discretization. Two step explicit finite element scheme is used to discretize the time function, which has advantage in problems treating large numbers of elements and unsteady state. The numerical simulation is compared with three cases; Case 1 does not consider the effect of wind, Case 2 and Case 3 consider the effect of summer and winter seasonal wind, respectively. According to result considering effect of seasonal wind, velocity of current vector shows slightly stronger than that of case 1 in the flow field. It can be concluded that the present method is a useful and effective tool in tidal current analysis.
        7.
        2005.12 KCI 등재 서비스 종료(열람 제한)
        Butyltin compounds (BTs), namely tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), were measured in surface and core sediments collected in 2001 inside Seogwipo Harbor, in order to evaluate their distribution characteristics. Seogwipo Harbor is one of major harbors of Jeju Island where a lot of shipping occurs and is designated as a trade port by the Korea Maritime and Port Law. BTs were detected in surface and core sediments of all stations and their concentrations in surface sediments were low, compared with to those in other sites of domestic and foreign countries. The main species among BTs was MBT, although there was a little difference with a survey site in surface sediments and in core sediments with depth. No or low correlations were obtained between organic matter or particles size of surface and core sediments and total BTs, indicating that these factors did not affect the distribution of BTs. It was estimated that more complex factors including BTs loads and surrounding sedimentary environments, affect the distribution of BTs. The high correlations between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints of vessel etc. and other sources, such as DBT and MBT, could be ignored. The butyltin degradation indices ([DBT] + [MBT]/[TBT]) in surface sediments were in the range of 2.0~3.8 (mean 3.0), indicating that the parent compound, TBT, were inflowed into the surface sediments a long years ago, degraded and deposited. The sedimentation age of BTs contaminated core sediments could not estimated because the content of 210Pb activity were nearly all the same and so the sedimentation rate could not obtained.
        8.
        2003.12 KCI 등재 서비스 종료(열람 제한)
        유한요소기법을 이용하여 유동해석의 수치모델을 행하였다 공간을 이산화 할 때에는 Galerkin법을 적용하였으며, 시간의 함수를 이산화 할 때에는 많은 수의 요소와 비정상상태의 문제를 다루는데 있어 장점을 가진 2단계 양해법을 이용하였다. 이동경계조건을 고려한 2차원유통모델을 개발하였고, 직사자형 수조에서 개발된 유동모델을 적용하여 검증하였고, 유용성을 확인하였다. 제주항에 개발된 이동경계기법을 적용하여 계산한 결과, 본 이동경계기법의 좋은 적용성을 보여주었다. 본 연구로부터 이동경계처리 방법이 실해역에서의 유동해석에 있어 유용하고 효율적인 방법이라고 결론지을 수 있다.
        9.
        2003.11 KCI 등재 서비스 종료(열람 제한)
        The surface sediments inside Hallim Harbor, one of the major harbors of Jeju Island, were sampled three times (June, September and December, 2001) and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), recommended by US-EPA as priority pollutants, to assess their distribution levels and to suggest their possible origins. The concentrations of PAHs ranged from 19 to 496 ng/g on a dry weight basis with a mean value of 245 ng/g, and the levels were low to moderate in comparison with other areas in the world. Based on comparisons of individual and total PAH concentrations with effects-based and equilibrium partitioning-based on sediment quality guidelines, the potential for the biological effects were expected to be low. The sedimentary PAHs may be correlated with organic carbon and mud contents to some extent. From the examinations of the four PAH origin indices, such as LMW/HMW (low molecular weight 2-3 ring PAHs over high molecular weight 4-6 ring PAHs), phenanthrene/anthracene ratio, fluoranthene/pyrene ratio, chrysene/benzo[a]anthracene ratio, it can be concluded that the sediment PAH contaminations were ascribed to both pyrolytic and petrogenic origins.
        10.
        2003.07 KCI 등재 서비스 종료(열람 제한)
        Butyltin compounds (BTs), namely tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), were measured in surface sediments collected in 2001 inside Hallim Harbor where a lot of shipping occurs as one of major harbors of Jeju Island, in order to evaluate their distribution. BTs were detected in surface sediments of all stations and their concentrations were comparable to those in surface sediments of other sites of domestic and foreign countries. The main species among BTs was MBT, although there was a little difference with a survey site. No correlations were obtained between organic matter or particles size of surface sediments and total BTs, indicating that these factors did not affect on the distribution of BTs. It was estimated that more complex factors including BTs loads and surrounding sedimentary environments, affected on the distribution of BTs. The high correlations between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints of vessel etc. and other sources, such as DBT and MBT, could be ignored. The butyltin degradation indexes ([DBT] + [MBT]/[TBT]) were in the range of 1.5~3.3 (mean 2.5), indicating that the parent compound, TBT, were inflowed into the surface sediments a long years ago and degraded.
        11.
        2003.03 KCI 등재 서비스 종료(열람 제한)
        In this study, the material cycle model was applied to suggest alternative management of water quality for Jeju Harbor. The distribution of COD, DIN (dissolved inorganic nitrogen) and DIP (dissolved inorganic phosphorus) concentrations was reasonably reproduced by simulations on the model area of the Jeju Harbor using a material cycle model. The simulations of COD, DIN and DIP concentrations were performed under the conditions of 20~100% pollution loadings reductions from pollution sources. In case of the 100% reduction of the input loads from Sanzi river, concentrations of COD, DIN and DIP were reduced to 39%, 78% and 52%, respectively at Jeju harbor. In contrast, in case of the pollutant loadings reductions from sediment, the effect of DIN and DIP reduction relatively seemed to increase around the center of study area. The 95% reduction of the pollutant loadings from river and sediment is required to meet the COD and nutrients concentration of second grade of ocean water quality criteria.
        12.
        2003.03 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to investigate the characteristics of water quality in Jeju harbor and to estimate pollutant loadings discharged into Jeju Harbor. To know characteristics of water quality in Jeju harbor and pollutant loadings of Sanzi river, we have investigated from August, 2000 to May, 2001. The results showed that the concentrations of COD, DIN and DIP were in the range of 1.00~4.85㎎/L (mean 2.15㎎/L), 2.14~74.0㎍-at/L(mean 12.20㎍-at/L) and 0.52~4.00㎍-at/L(mean 1.18㎍-at/L), respectively. These values were under Ⅲ class of seawater quality criteria. The ratio of nitrogen to phosphorus was lower than 16 except for Station 1 in Jeju harbor. Therefore, nitrogen was playing an important role in phytoplankton growth as limiting factor in Jeju harbor. The mean values of eutrophication index were exceeding 1, which was the eutrophication criteria. The results of estimating pollutant loadings at Sanzi river are 0.30 ton/day for COD, 300㎏/day for DIN and 18.0㎏/day for DIP, respectively.
        13.
        2002.03 KCI 등재 서비스 종료(열람 제한)
        80,000 G/T급 크루즈선이 입항할 수 있는 터미널을 계획하고 있는 제주신항에 대하여 자연 ·환경 조건 및 방파제 등의 구조물 등을 고려하여 선박조종시뮬레이션을 실시하여 입 ·출항 및 접 이안의 안전성을 평가하고자 한다. 안전성 평가는 항로경계의 침범여부, 구조물과의 최근접거리, 선박조종자의 주관적 평가를 통계적으로 해석하는 방법을 이용하였다.