• Journal of the Korean GEO-environmental Society
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• v.12 no.2
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• pp.55-61
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• 2011

NDMA(N-Nitrosodimethylamine) has been considered as a carcinogenic pollutant even at extremely low-concentration (10ng/L). However, previous researches on NDMA have focused on mainly high concentration due to a difficulty of analysis. In this study, removal efficiencies were evaluated for individual or combined methods with PAC(Powder Activated Carbon), GS(Granular Sludge), MF(Microfiltration), UF(Ultrafiltration) and Silica gel(MCM-41, Diatomite, Spherical silica gel) at both aerobic and anaerobic conditions. Combined method of GS, PAC and UF membrane at anaerobic condition showed the highest removal efficiency of 65% while Silica gel showed the lowest removal efficiency of 6%. The outcomes of this study could be used further study of extremely low-concentration NDMA removal.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.521-547
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• 2018

To provide fundamental information to areas that lack data on the plant resources and the ecosystem, this study conducted a survey on the vascular plants in Mt. Jigisan in Hongseonggun. The vascular plants identified during the six-round field surveys were a total of 443 taxa: 96 families, 286 genera, 391 species, 7 subspecies, 40 varieties, 3 forms, and 2 hybrids. On floristic regional of Korea, Mt. Jigisan is deciduous broad-leaved and conifer-mixed forest which is south province of Korean peninsula. 4 taxa of Korean endemic plants such as Populus ${\times}$ tomentiglandulosa, Forsytsythia koreana, Forsytsythia ovate, and Iris rossii var. latifolia were collected. The vascular plants on the red list according to IUCN evaluation basis were found to be 6 taxa: Vulnerable (VU) species of Forsytsythia ovata, Least Conern (LC) species of Chionanthus retusus, Pseudoraphis ukishiba, and Cymbidium goeringii, and Not Evaluate (NE) species of Panax ginseng, and Fimbristylis verrucifera. The floristic regional indicator plants were found 27 taxa: 2 taxa of grade V, 3 taxa of grade IV, 6 taxa of grade III, 4 taxa of grade II, and 12 taxa of grade I. The specific distribution plants were found 27 taxa: 4 taxa of northern part of plants, 12 taxa of southern part of plants, 10 taxa of isolation distribution of plants, and 1 taxon of recently reported Viola betonicifolia var. albescens. The invasive alien plants were identified as 67 taxa. The naturalized index (NI) was 15.12%, and urbanization index (UI) was 20.9%, respectively.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.46.2-46.2
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• 2009

In vitro 상에서 골조직을 원활하게 재생하기 위해서는 3차원 지지체를 이용한 세포 배양과 세포 배양 시 세포의 형태와 기능을 유지/향상시키기 위한 인체 내 미세 환경 재현은 필수적이다. 따라서 본 연구에서는 뼈 성분과 유사한 생체 활성 물질인 hydroxyapatite (HA)와 생분해성 고분자인 poly $\varepsilon$-caprolactone (PCL)를 복합재료로 이용하여 내부 연결성이 우수한 골조직 재생용 3차원 지지체를 제작하였으며, 골 재생 능력 향상을 위하여 인체내 골조직의 기계적 미세 환경을 체외에서 구현한 새로운 형태의 perfusion bioreactor system을 개발/적용하였다. 또한 본 연구에서 개발된 perfusion bioreactor system의 생물학적 평가를 위해 MG63 (osteoblast like cell, 한국 세포주 은행)과 New Zealand White Rabbit에서 분리한 중간엽 줄기세포를 골조직 재생용 3차원 지지체에 파종하였다. 48시간 동안 안정화 후 perfusion bioreactor system을 이용하여 기계적 자극을 파종된 세포에 인가하였으며, 배양 기간 동안 세포의 증식 확인 및 형태학적 관찰을 실시하였다. 본 연구 결과, perfusion bioreactor system을 이용하여 기계적 자극을 인가한 실험군에서 세포의 증식 및 활성도가 대조군에 비해 우수함을 확인 할 수 있었다. 따라서, perfusion bioreactor를 이용한 세포 배양은 세포의 활성 향상 및 골조직 재생에 도움이 될 것으로 사료된다. 차후 perfusion bioreactor를 이용한 다양한 패턴의 자극이 골재생 능력 및 중간엽 줄기세포의 골 분화능에 미치는 영향에 대한 연구가 필요할 것으로 사료된다.

• Environmental Analysis Health and Toxicology
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• v.14 no.4
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• pp.135-144
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• 1999

Environmental toxicities of priority water pollutants were evaluated by two selected bioassays, Lettuce seed germination/elongation test and Microtox acute toxicity test. Toxic chemicals (heavy metals, polycyclic aromatic hydrocarbons, and phenolic compounds) inhibited the germination rate and root elongation of Lettuce seed, as well as the bioluminescence of Microtox bacteria. When test biota were exposed to target chemicals, the sensitivity of Lettuce bioassay was relatively lower than that of Microtox bioassay. However, Lettuce bioassay may be a good candidate for prescreening the environmental toxicities of priority water pollutants, since the testing method with Lettuce seed was relatively easier and more economic than with Microtox bacteria. Toxicity tests were conducted to compare the validity and sensitivity of both bioassays for sediment from a small stream passed through urban area as well as leachate from a municipal solid waste landfill. From experimental results, we found that Lettuce test and Microtox test are compensated each other as a battery of bioassay for evaluating the environmental toxicities of field samples obtained from a small stream contaminated by pollutants.

• Journal of Korean Society on Water Environment
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• v.32 no.1
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• pp.1-14
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• 2016

This study was conducted to develop a Benthic macroinvertebrates streambed index (BMSI) based on the response of the community to the substrate type of streambed. Analyzing the seasonal (Spring and Fall) data (11,367 sampling units) surveyed and collected during 2008~2014 at 960 sites in South Korea, we estimated the lithophility of 191 taxa. BMSI was composed of the lithophilic value, indicator weight value and individual abundance frequency. It showed an extremely significant correlation (r = -0.8, p<0.001) with the mean grain size (in phi-value) of the streambed.

• Journal of Korean Society on Water Environment
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• v.32 no.4
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• pp.343-348
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• 2016

A chemical sequencing batch reactor was operated to test the feasibility of nutrient recovery from a biological livestock wastewater treatment plant. Both phosphate and ammonia could be successfully recovered as magnesium ammonium phosphate (MAP) crystals. The contents of TP and TN in the recovered MAP crystals were 26.2% and 4.0%, respectively. Zn, Cr and Ti were identified in the crystals, but the contents remained below the Korean standard for an organic fertilizer. Chemical analyses confirmed that the MAP crystals could be useful phosphate fertilizers. On the other hand, the results of physical analyses using an X-ray diffractometer and an energy dispersive X-ray spectrometer strongly suggested that crystalline materials like magnesium potassium phosphate (KMP) and hydroxyapatite (HAP) were also formed during the MAP crystallization, depending on the availability of K⁺ and Ca²⁺.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.344-347
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• 2003

본 조사를 통해 토양오염유발시설 중 유류 유출사고가 잦은 주유소에서의 오염현황 조사방법과 오염토양에 대한 적정한 정화기법을 제시하고자 하였다. 오염현황 조사결과, 지층구조 는 전반적으로 Clay로 구성되어 있으나 오염토양 주변은 비교적 투수도와 통기성이 우수한 Silty Sand층을 나타내고 있었다. 본 주유소의 경우 주유기 주변(상층부)과 지하유류저장탱크 주변(수직분포)에 오염이 분포되어 있고, 오염원인은 주유기의 배관 파손 및 결함에 의해 발생한 것으로 예상된다. 본 조사지역에 대한 정화기법으로는 토양증기추출기술(SVE)과 불포화대를 생물학적으로 복원할 수 있는 바이오벤팅기술을 결합시킨 Bioslurping이 효과적일 것으로 평가된다. 또한 Bioslurry injection treatment를 병행하여 효과적으로 고농도의 오염토양을 처리하는 것이 바람직할 것으로 판단된다.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.606-614
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• 2009

To evaluate the biological water quality, diatom-based biological indices (DAIpo and TDI) were examined in the Sum-River and the Dal-stream. Having BOD concentrations below $2mg{\cdot}L^{-1}$ in most sites, water quality of both rivers was good. The DAIpo and TDI values ranged from 29.8 to 91.4 and from 38.7 to 93.0 respectively. From the biological water quality assessment, DAIpo and TDI for both rivers displayed fair to fairly poor water quality levels. However, the two indices showed more polluted conditions than expected from the BOD vlaues. In addition, DAIpo, having wider range of differences, appears to be more sensitive to the change in water quality when compared to TDI values. Statistical analysis using principal component analysis showed that Nitzschia palea and Diatoma vulgare might not be the appropriate indicators due to their low correlations with other indicators.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.121-123
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• 1999

Bio-Aerosol Concentrator Inlets were made to collect particles of which size was $2\mu\textrm{m}$ as aerodynamic diameter or larger. The Concentrator Inlets were designed by using virtual impactors, because the virtual impactors are known for high efficiency. In a virtual impactor, the intake air is typically divided into two streams with the major and the minor flow. In this work, several types of the acceleration nozzles and collection probes were designed. Subsequently, the results were evaluated experimentally. It was found that if controled properly, the velocity can improve substantially the aerosol concentration performance. The diameter of acceleration nozzle and type of collection probe were varied to obtain the optimum design. Subsequently, the different designs were compared respectively and the best design among them was identified. It is expected that this new finding can help improve design of future Aerosol Concentrator for high concentration rate.

• Journal of Environmental Science International
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• v.8 no.1
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• pp.1-6
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• 1999

This study was carried out to evaluate off-shore water quality and to draw marine pollution map to Southern sea in Korea by bioassay using gametes and early development system of Asterias amurensis. From the bioassay, it was determined that the water qualites of Southern sea maintained the grade II, because development of A. amurensis were moderately inhibited. However, Sunchon, Kwangyang, and Jinhae Bay belonged to grade III, because development of A. amurensis were strongly inhibited. This could be due to the inflows of several river systems and poor water circulation. The water quality at Yosu island was the grade I, because A. amurensis were not inhibited in its early development.