• 자원환경지질
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• 제29권1호
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• pp.77-85
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• 1996

The vertical concentration profiles of chromium in sediment cores were measured from Lakes Superior, Michigan, and Ontario in an attempt to determine spatial and historical variations. Pre-industrial concentrations of chromium are typical for soils in the Great Lakes region. Only Lakes Ontario and Michigan exhibit anthropogenic enrichments of chromium in the sediments. Sediment profiles in Lakes Ontario and Michigan indicate that the rates of anthropogenic chromium loading to the Great Lakes region are decreasing. Focusing corrected inventories are similar within each lake and those are higher in Lake Ontario than Lake Michigan. The results are interpreted to indicate that there is a small atmospheric component to chromium inputs to the Great Lakes and that the relative importance of this input decreases from Lake Superior to Lake Ontario.

• Environmental Engineering Research
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• 제10권6호
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• pp.306-315
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• 2005

Total gas phase mercury (TGM) concentrations and event wet-only precipitation for Hg were collected for nine months (from April, 2002 to Dec., 2002) at Sterling, NY on the shoreline of Lake Ontario. TGM concentrations measured in this study ($3.02{\pm}2.14\;ng/m^3$) were in somewhat high range compared to other background sites. Using simplified quantitative transport bias analysis (SQTBA) possible sources affecting high Hg concentration in Sterling was identified, and they are coal-fired power plants located in southern NY and Pennsylvania. Wet deposition measured at Mercury Deposition Network (MDN) sites including Pt. Petre and Egbert, ON were compared with data obtained at the Sterling to estimate the total mercury wet deposition flux to Lake Ontario. The wet deposition flux was calculated to be the highest at the Sterling site ($7.94\;{\mu}g/m^2$ from April, 2002 to Dec. 2002) and the lowest at the Egbert ($3.92\;{\mu}g/m^2$), due to the both the difference in precipitation depth and Hg concentration in the precipitation. The deposition measured at the Sterling site is similar to Lake Michigan deposition of $6-14\;{\mu}g/m^2$ (converted for ninth months) measured for Lake Michigan Mass Balance Study (LMMBS).

• 응용통계연구
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• 제16권1호
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• pp.15-31
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• 2003

Lake Ontario에서 수년간 측정된 실제 생물학적 지표 자료의 각 변수에 대하여 관찰시점의 불규칙성과 의존성을 고려한 탐색적 분석모형의 수립과정에 대하여 연구하였다. 이 상점을 제거한 후 trend와 seasonal component를 수정 한 선형 모형으로부터 잔차를 계산하고 이로부터 variogram과 correlogram을 그려보았다.

• ALGAE
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• 제36권3호
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• pp.195-206
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• 2021

Increasing inputs of dissolved organic matter (DOM) to northern lakes is resulting in 'lake browning.' Lake browning profoundly affects phytoplankton community composition by modifying two important environmental drivers-light and nutrients. The impact of increased DOM on native isolates of red and green-pigmented cyanobacteria identified as Pseudanabaena, which emerged from a Dolichospermum bloom (Dickson Lake, Algonquin Provincial Park, Ontario, Canada) in 2015, were examined under controlled laboratory conditions. The genomes were sequenced to identify phylogenetic relatedness and physiological similarities, and the physical and chemical effects of increased DOM on cellular performance and competitiveness were assessed. Our study findings were that the isolated red and green phenotypes are two distinct species belonging to the genus Pseudanabaena; that both isolates remained physiologically unaffected when grown independently under defined DOM regimes; and that neither red nor green phenotype achieved a competitive advantage when grown together under defined DOM regimes. While photosynthetic pigment diversity among phytoplankton offers niche-differentiation opportunities, the results of this study illustrate the coexistence of two distinct photosynthetic pigment phenotypes under increasing DOM conditions.

• 물과 미래
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• 제29권6호
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• pp.141-154
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• 1996

열 유동 현상을 규명하기 위한 연구로서 2차원 연직 좌표계의 수체 유동 컴퓨터 프로그램을 개발하였다. 이러한 연구의 구체적인 목적은 일차침전조 같은 폐수나 용수처리 및 상수원 호소에서의 수체유동에 대한 기작을 파악하고자 함이다. 이렇게 개발한 컴퓨터 프로그램 성능을 문헌에 나타난 수치해석 및 실험 자료와 성공적으로 비교, 검증하였다. 첫 번째 검증 문제는 응축열 방출에 따른 수체유동해석에 대한 것이며 두 번째 문제는 캐나다 온타리오주 사리나시에 있는 일차침전조에 대한 수치해석 실험 결과이다. 이렇게 개발된 컴퓨터 프로그램은 2차원 호소의 전도와 같은 특성규명에 응용하였으며 주요 변수로는 유량, 바람의 속도 그리고 온도 분포 등을 고려하였다. 나아가서 호소의 전도 현상과 같은 유동 특성을 규명하기 위한 연구의 일환으로서 바람의 속도나 온도 분포에 따른 수치해석을 시도하였다. 결과는 물리적으로 일관성 있게 나타났으며 수체 유동 특성 규명을 위한 유용한 도구로서 가능성을 보였다.

• 한국물환경학회지
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• 제35권2호
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• pp.105-114
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• 2019

The objective of this study was to investigate the pollution assessment of organic matters, nutrients, and metals in sediment in major lakes (5 lakes and 17 sites) of Buk-han river using various sediment pollution assessment guidelines and indices. The concentrations of organic matters and nutrients were lower than class IV (Sediment pollution assessment guidelines of Korea) and Severe Effect Level (SEL, Sediment pollution assessment guidelines of Ontario). This results indicated that the lakes sediments were unpolluted and tolerable level for sediment dwelling organisms by organic matters and nutrients. However, several sites of Chuncheon and Soyang lakes were evaluated "heavily polluted" level by organic index (Org-index). The order of lakes by metals concentrations from the one with the highest concentration was Hwacheon, Chuncheon, Cheongpyeong, Uiam, Soyang. All lakes except Hwacheon were assessed unpolluted to marginally and tolerable level for sediment dwelling organisms by metals based on sediment pollution assessment guidelines (Korean and Ontario), indices of geoaccumulation ($I_{geo}$), pollution loading (PLI) and ecological risk (RI). In Lake Hwacheon, every investigated sites were polluted with metals, especially Hg, based on sediment pollution assessment guideline of Korea and indices ($I_{geo}$, PLI and RI). The dwelling organisms in sediment of Hwacheon Lake were likely to be severed by metals.

• 한국토양비료학회지
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• 제45권6호
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• pp.882-889
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• 2012

대관령 고랭지 농업지대 인근 주요 하천과 도암호의 수질의 이화학성 및 식물성플라크톤의 발생 양상을 조사하여 남한강 상류 수계의 전반적인 수질특성을 파악하고자 하였다. 도암호의 화학적 산소 요구량 (COD)은 $6.1mg\;L^{-1}$ 이고, 총 인 (Total phosphorous)의 함량은 0.26 으로 호소수 생활환경 기준 VI등급 보다 높았다. 부유물질은 평균 9.77 NTU로 호수수 생활기준 보다 높았다. 식물플랑크톤의 농도는 7월부터 9월까지 $2.0{\times}10^3cells\;mL^{-1}$ 이상으로 확인되었는데 이는 여름철 고온과 강우에 의해 영양물질의 대량 유입으로 인해 남조류가 발생하였기 때문인 것으로 생각된다. 온타리오 퇴적물 기준과 비교해 보면, 도암호의 총 질소 및 총 인의 농도는 LEL과 SEL의 중간 정도 값을 보여 오염이 상당부분 진행되어 체계적인 관리로 오염원을 저감 및 차단할 수 있는 방안이 마련되어져야 할 것으로 생각된다.

• 가정과삶의질연구
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• 제27권4호
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• pp.1-18
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• 2009

This study has been performed to explore process of forming low cost small site housing communities and residential lives of the young elderly around small cities along rural counties of America and Canada, and suggest future implications for Korea. In this study, five low cost small housing zones such as cottage and mobile home parks in non-metropolitan counties of California and Ontario State such as Weed, Paradise, Sun City,, Wellington on the Lake, and Trenton were visited and the elderly residents and service experts were interviewed. The senior concentrating housing clusters were formed primarily from influx of both metropolitan and rural residents for the purpose of seeking warmful localities, traffic connections, and business purposes in theme focused production areas. On the other hand, residential lives in the zones are occasionally negatively influenced by unbalanced concentrations of elderly facilities such as nursing stations and funeral homes. For the future of Korean rural elderly policies, suggestions are made as follows: first, integrated forms of urban and rural township need to be settled as attracting places for early retiring people who seek low cost pastoral oriented but culturally activated environment. Second, a model town of mobile housing structures needs to be initiated as a measure of evaluating adaptation process of those movers. Third, a cooperation system among governmental ministries needs to be formed in order to integrate a long term master plan of establishing traditional rural town of independent housing districts. fourth, productive and active lifestyles need to be maintained for government lead retirement rural villages by limiting expansion of nursing related facilities around the independent areas. Fifth, visiting welfare service programs and volunteer groups need to be further developed for the housing area especially in winter time, when social integration and emotional comforts are extremely limited.

• 한국대기환경학회지
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• 제22권2호
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• pp.179-189
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• 2006

Ambient gas phase mercury concentrations including elemental mercury ($Hg^0$) were measured at the Potsdam, Stockton, and Sterling sites in NY from 2000 to 2003. Also, concentrations of ambient reactive gaseous mercury (RGM; $Hg^{2+}$) were measured at the Potsdam site during one year. The contribution of RGM($4.2{\pm}6.4pg/m^3$) was about $0.2{\sim}3%$ of the total gas phase mercury concentration measured (TGM: $1.84{\pm}1.24,\;1.83{\pm}0.32,\;3.02{\pm}2.14ng/m^3$ in Potsdam. Stockton, and Sterling, respectively) at the receptor sites. Potential Source Contribution Function (PSCF), a hybrid receptor modeling incorporating backward trajectories was performed to identify source areas of TGM. Using PSCF, southern New York, North Carolina, and eastern Massachusetts were identified as important source areas in the United States, while the copper smelters and waste incinerators located in eastern Quebec and Ontario were determined to be significant sources in Canada. The Atlantic Ocean was suggested to be a possible mercury source. PSCF incorporating back-dispersion and deposition was applied for RGM , as well as PSCF based on 2-days back-trajectories. Two different approaches yielded considerably different results, primarily due to the consideration of dispersion rather than deposition. Using back-trajectory based PSCF, eastern Ohio, southern New York, and southern Pennsylvania where large coal -fired power plants area located were identified as the large sources in US. Metallurgical industry located in eastern Quebec was resolved as well. From the result of back-dispersion and deposition based PSCF, Pennsylvania, mining facilities around Lake Superior, Toronto, Boston, MA, Quebec, and coal power plants in NY were identified to be the significant source areas for Potsdam site.