• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.364-373
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• 2009

We evaluated stream health, based on integrative approaches of qualitative habitat evaluation index (QHEI), chemical water quality and the index of biological integrity (IBI) using fish assemblages in Daejeon Stream during August 2004 - October 2007. The QHEI values in this study averaged 78.2 (n=28, range: 47$\sim$124), indicating "fair" condition based on the criteria of US EPA (1993). The highest value was in the headwater site (S1) that was 112 (good), whereas the value in S3, mid and downstream was SS (fair-poor) that was the lowest owing to a disturbance on the bed and an artificial bank. Concentrations of chemical parameters such as BOD, TP and conductivity increased from the upstream to the downstream due to higher inputs of organic matters and nutrients from the urban area. Conductivity and TP showed a dilution of stream water by rainwater during summer monsoon. Analysis of fish compositions showed that total number of species was 24 and Zacco platypus was predominated (82%). The mean IBI was 17 (range: 12$\sim$30) during four years and the IBI values also decreased from S1 to S4. These results indicated that ecological health was degradated distinctly as the stream goes down through the city-center. We concluded that Daejeon Stream running through the city are influenced by chemical impact such as an influx of domestic sewage as well as the quality of habitat.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.654-660
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• 2006

This study investigated the discharge characteristics of combined sewer overflows(CSOs) at a small watershed located in the Ojeong-cheon area of the Daejeon-cheon, Daejeon City. The long-term variations of discharges, water quality, and SS loads from 2001 to 2004 were simulated using SWMM. The simulation results indicated that suspended solid(SS) loads during the rainy seasons(July${\sim}$August) were highest throughout the whole year, but not substantially higher than those during the dry seasons. This result is due to the fact that contaminants do not buildup significantly because of frequent rainfall events during the wet seasons. It was estimated that about 9.3% of SS was discharged to the receiving body the during dry seasons while 90.7% during the rainy seasons. Further analysis showed that during the wet seasons SS loads discharged at the site as CSOs and at the wastewater treatment plant without treatment were 38% and 62%, respectively.

• Economic and Environmental Geology
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• v.42 no.4
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• pp.315-333
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• 2009

In this study, the hydrochemical and the isotopic characteristics of major streams in the Daejeon area were investigated during rainy and dry seasons. The stream water shows the electrical conductivity of the range of $37{\sim}527{\mu}s$/cm, and pH $6.21{\sim}9.83$. The chemical composition of stream waters can be grouped as three types: the upper streams of Ca(Mg)-$HCO_3$ type, Ca(Mg)-$SO_4(Cl)$ type of middle streams flowing through urban area, and Na(Ca)-$HCO_3$(Cl, $SO_4$) type of the down streams. Based on in-situ investigation, the high pH of stream waters flowing through urban area is likely to be caused by the inflow of a synthetic detergent discharging from the apartment complex. The electrical conductivity of stream waters at a dry season is higher than those of at a rainy season. We suggest that the hydro-chemical composition of stream waters in the Daejeon area was affected by the discharging water from the sewage treatment facilities and anthropogenic contaminants as well as the interaction with soil and rocks. ${\delta}D$ and ${\delta}^{18}O$ values of the stream waters show the relationship of ${\delta}D=6.45{\delta}^{18}O-7.4$, which is plotted at a lower area than global meteoric water line(GMWL) of Craig(1961). It is likely that this isotopic range results from the evaporation effect of stram waters and the change of an air mass. The isotope value shows an increasing trend from upper stream to lower stream, that reflects the isotopic altitude effect. The relationship between ${\delta}^{13}C$ and $EpCO_2$ indicates that the carbon as bicarbonate in stream water is mainly originated from $CO_2$ in the air and organic materials. The increasing trend of ${\delta}^{13}C$ value from upper stream waters to lower stream waters can be attributed to the following reasons: (1) an increasing dissolution of $CO_2$ gas from a contaminated air in downtown area of the Daejeon, and (2) the increment of an inorganic carbon of groundwater inflowed into stream by base flow. Based on the relationship between ${\delta}^{34}S$ and $SO_4$ of stream waters, the stream waters can be divided into four groups. $SO_4$ content increases as a following order: upper and middle Gab stream${\delta}^{34}S$ value decreases as above order. ${\delta}^{34}S$ value indicates that sulfur of stream waters is mainly originated from atmosphere, and is additionally supplied by pyrite source according to the increase of sulfate content. The sulfur isotope analysis of a synthetic detergent and sewage water as a potential source of the sulfur in stream waters is furtherly needed.

• The Journal of Internal Korean Medicine
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• v.44 no.3
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• pp.294-312
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• 2023

Objective: The purpose of this study is to evaluate the effects of GGX on an ovalbumin (OVA)-induced asthma mice model. Methods: Balb/c mice were challenged with OVA and then treated with three concentrations of GGX (100, 200, and 400 mg/kg). After sacrifice, the bronchoalveolar lavage fluid (BALF) or lungs of the mice were analyzed by fluorescence-activated cell sorting, ELISA, real-time PCR, H&E, Masson's trichrome, PAS and AB-PAS staining, and immunohistofluorescence staining. Results: GGX significantly inhibited the increase of total cells, immune cells (lymphocyte, neutrophils, macrophage, CD4+, CD8+, CD4+CD69+, CD62L-CD44high+, Gr-1+SiglecF-), and the expression of cytokines (IL-4, IL-5, IL-13, IFN-γ) in BALF. It also significantly inhibited the increase of total cells, immune cells (lymphocyte, neutrophils, eosinophil/macrophage, CD3+, CD19+, CD3+CD193+, CD4+, CD8+, CD4+CD69+, CD62L-CD44high+, and Gr-1+SiglecF-), and the expression of IL-13, TARC, and MCP-1 in lung tissue. GGX decreased the severity of histological lung injury and the expressions of STAT3 and GATA3. Conclusion: This study suggests the probability of using GGX for the treatment of asthma by inhibiting inflammatory immune response.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.185-191
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• 2001

The morphological variation and density of the Euglena viridis cells and environmental factors of urban waterways of Daejoncheon , Jeonjucheon, Kwangjucheon, Kumhogang, Mihocheon,and Musimcheon, Korea were studied from 25December, 1995 to 5 January, 1997 in order toelucidate possible relationships among the bio-logical and abiological factors. All E. viridis cells were same in having single star-cluster of chlo-roplast lobes and included two morphotypes based on other detailed morphology. The morphotype I cells agreed well with the typical form off. viridrs and commonly occurred in most of waters and bloomed with $5386\;cells\;{\cdot}\;mL^{-1}$ in Kwangjucheon. The density of the morphotype Ipositively correlated with ammonium (r = 0.80)and nitrite (r = 0.68), while negatively with nit-rate concentration. The morphotype II cells were characterized by having randomly scattered cytoplasmic granules beneath pellicle and unevenmargined lobes of chloroplasts. The density of the morphotype II positively correlated with nitrate (r = 0.98), while negatively correlated with ammonium and nitrite. However, the density of each morphotype was not significantly related with inorganic phosphate, temperature and pH of surface water. These results indicate that E. viridis includes two morphotypes in urban waterways in Korea, that coexist in the same period and station as a response of allocation of nitrogenous nutrients.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2995-3000
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• 2008

Understanding of the impinging behavior of an electrically charged spray is essential in determining appropriate operating conditions for electro-spraying of paints, surface coating materials and insecticides. In the present work, the wall impact behavior of an electrically charged drop has been investigated and compared with that of a neutral drop experimentally. The critical Sommerfeld number representing the spread-splash boundary for the charged drop impacting on the dielectric substrate turned out to be larger compared to that for the neutral drop with the same surface condition. The change of the transition boundary is due to the increase in the surface wettability of the drop on the substrate. However, with the electrically conducting substrates, the charging effect on the transition boundary appeared negligible. This is because the electric discharging time is much shorter than the time required for the flattened drop to reach its maximum extent.

• 핵융합뉴스레터
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• s.46
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• pp.6-9
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• 2010

2008년 7월 최초 발생 성공 이후 지난 해 본격 가동에 들어서며 기대 이상의 운영성과를 냈던 한국의 태양 KSTAR가 3번째 실험에 들어간다. 금년 실험은 지난해보다 가열장치, 진공용기 내부 장치 등 향상된 장치 성능을 바탕으로 1천만도 이상의 초고온 플라즈마 발생 및 핵융합 반응을 통한 중성자 검출 등을 목표로 한다. 특히 오는 10월 대전에서 열리는 IAEA 국제핵융합에너지 컨퍼런스(FEC)에서 이번 KSTAR의 실험 성과를 발표할 예정으로 어느 때보다 세계 핵융합연구자들의 시선이 KSTAR로 몰리게 될 것으로 기대하고 있다.

• 프린팅코리아
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• v.11 no.9
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• pp.62-84
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• 2012

국내 최대 인쇄인의 축제인 제19회 국제인쇄산업대전(KIPES 2012)이 오는 9월 5일(수)부터 8일(토)까지 일산 킨텍스 전시장에서 개최된다. 대한인쇄문화협회와 한국이앤엑스가 공동으로 주최하고 문화체육관광부, 지식경제부, 경기도, KOTRA, 대한인쇄정보산업협동조합연합회, 대한인쇄기술협회, 서울특별시인쇄정보산업협동조합, 한국디자인단체총연합회, 대한인쇄연구소, 한국제책공업협동조합, 한국스크린인쇄공업협회가 후원하는 이번 전시회는 킨텍스 제1전시장 1, 2홀에서 1만5천$m^2$ 규모로 개최된다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.440-445
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• 2004

본 연구는 대천 유성지역 유성천 소유역에서 강우시 유출수문곡선으로부허 기저유출성분과 강우성분을 분리하여 동적 평형에 의한 강우의 지하수 함양률을 추정하기 위해서 수행되었다. 보존적인 산소동위원소(18O) 추적자를 이용하여 2성분(기저유출성분과 강우성분) 유출수문곡선 분리하였으며 이로부터 추정된 지하수 함양률은 강우의 0.13이었다. 추적자를 이용한 유출수문곡선분리는 지하수 함양률을 정량적으로 나타낼 수 있다는데 의의가 있다.

• 전기의세계
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• v.41 no.1
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• pp.7-8
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• 1992

전기학회는 반세기에 걸쳐 눈부신 발전을 거듭해오고 있으며, 그동안 학회에 참여한 회원수는 약8천여명에 달할 것으로 추산되고, 1992년 1월 현재 정회원 2,017명, 종신회원 901명, 준회원 469명, 학생회원 152명, 특별회원 148개소, 합계 3,687명이 본학회에서 활동하고 있다. 본학회는 지역간의 균형있는 발전을 위하여 전국에 11개 지부(부산(221), 대전(276), 울산(263), 대구(164), 광주/전남(126), 전북(65), 포항(171), 마산/창원(239), 충북(76), 광양(81), 강원(109), 괄오한은 회원수임)를 설치운용하고 있다.