• 생태와환경
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• 제43권3호
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• pp.418-427
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• 2010

우포늪의 4개 습지를 대상으로 2005년 3월부터 2009년 12월까지 매월 영양염과 엽록소-$\alpha$ 농도를 모니터링 하였으며, 이를 토대로 수질 영양 단계를 평가하였다. 질산성질소와 암모니아성질소, 총질소 등 질소 계열 영양염은 선행 연구 결과와 비교시 감소한 것으로 나타났다. 그러나 총질소의 경우, 아직까지 수화발생 기준과 부영양 기준 농도를 상당히 초과하여 용존되어 있는 것으로 확인되었다. 인산염인과 총인 농도 또한 선행 연구와 비교 시 상당히 감소한 것으로 조사되었으나, 총인은 총질소와 마찬가지로 부영양 기준을 초과하여 용존되어 있었다. 질소 계열과 인 계열 영양염은 4개 습지 중 쪽지벌에서 가장 낮은 것으로 조사되었다. 엽록소-$\alpha$의 평균 농도는 우포에서 가장 높게 나타났으며, 목포에서 가장 낮게 나타났다. 쪽지벌과 목포에서는 하계에 높게 나타났고, 우포와 사지포에서는 비하계 기간 동안 높게 나타났다. TRIX 분석을 통해 우포늪의 수질 영양 상태를 평가한 결과 4개 습지 모두 생산성이 높고 영양 단계가 높은 수질을 의미하는 poor water quality 상태로 조사되었다.

• Journal of Photoscience
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• 제3권3호
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• pp.153-158
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• 1996

The effects of $\alpha$- and $\beta$-cyclodextrins (CD) on the twisted intramolecular charge transfer (TICT) behavior of p-N,N'-dimethylaminobenzoic acid (DMABA) in buffered aqueous solution have been investigated by examining formation and decay behaviors of the TICT-typical dual fluorescence. The ratio of the TICT emission to the normal emission (I$_a$/I$_b$) increases linearly $\alpha$-CD concentration increases, while in the presence of $\beta$-CD it shows nonlinear dependences on the CD concentration. The analysis of the CD-dependent changes of the I$_a$/I$_b$ and absorption spectra demonstrates formation of 1:1 inclusion complexes between DMABA and CDs. The decay time of the normal emission (ca. 700 ps) is little affected by the formation of $\alpha$-CD inclusion complex, whereas it increases upto ca. 1.6 ns upon formation of $\beta$-CD inclusion complex. The TICT emission for the $\beta$-CD inclusion complex exhibits two decay components while it shows a single component for the $\alpha$-CD inclusion complex, indicating formation of one or two types of inclusion complex in the presence of $\alpha$-CD or $\beta$-CD, respectively. These results are attributed to the CD cavity size dependence on patterns of complexation between CDs and DMABA. The CD size dependences of the TICT fluorescence properties with the orientation of the guest molecule demonstrate that the specific hydrogen bonding between the carboxylic acid group and water plays an important role in the excited-state TICT.

• 생태와환경
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• 제55권2호
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• pp.156-166
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• 2022

호소의 수질 특성을 이해하는 것은 호소 및 정수생태계 관리의 가장 기본 요소이다. 호소의 수질은 호소의 수리수문학적 요소, 주변 토지 이용/피복, 유역 내 인간 활동을 포함한 다양한 요인에 의해 영향을 받는다. 본 연구에서는 호소에서 5년 동안(2015~2019) 측정된 9가지 이화학적 요인(pH, DO, COD, TSS, T-N, T-P, TOC, EC, Chl-a)을 이용하여, 국내 83개 주요 호소를 수질에 따라 분류하였다. 계층적 그룹 분석을 통해 전체 호소는 총 5개의 유형으로 분류되었고, 각 유형별로 저수지의 수질 및 고도, 유역면적, 만수위, 총 저수량과 같은 수리수문학적 요인을 반영하였다. 특히 저고도에 위치한 대형 호소에서(그룹 I) 수질이 매우 낮게 나타났다. 한국형 부영양화 지수를 이용하여 국내 주요 호소의 부영양화 정도를 비교한 결과, 석호가 포함된 그룹 IV 및 신갈지 등에서는 과거 2004~2008년에 비해 부영양화 지수가 개선되었으나, 그룹 I, III, V에 속한 대부분의 농업용 저수지에서는 부영양화가 심화되었다.

• 한국환경복원기술학회지
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• 제20권4호
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• pp.1-13
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• 2017

The purpose of this study is to analyze a term of decade of water quality data of the Mulgum intake station on the Nakdong river(dam) to find the cause of algal blooms and to set an alternative to prevent artificial lake water pollution. Our study shows that water quality changes have regular periodic regularity and there was a certain correlation between specific analytical items. According to the analysis results of each factor, the decline in precipitation was not the main reason for algal blooms. TP concentration had a slight effect on Chl-a concentration but was not a limiting nutrient of a bloom. TN concentration had a strong correlation with Chl-a and strongly negative correlation with temperature, but was not a bloom's limiting nutrient, and was only a dependent variable. As the temperature was negatively correlated with the Chl-a concentration, it is found that the aspect of the ecological influence of the temperature was the most important factor of the phytoplankton concentration change. The N/P ratio lies under a power function with a high degree of reliability by the TP concentration, and the phenomenon appeared to be the same as the results of two other comparative areas. This result confirms that TN is dependent on TP and the biota in the lake that TN is a dependent variable whose concentration is determined by TP it. In conclusion, the increase in lake bloom is the result of a food chain change, and it is necessary to control the ecosystem by the food chain in the lake in order to reduce the lake's bloom. In particular, it is important to keep the benthic ecosystem as wide as possible in the aerobic state.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권3호
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• pp.41-50
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• 2015

Hydrogeologic environment of the Mega City such as Seoul, suffers from rapid changes caused by urbanization, construction of underground subway or buildings, and contaminant loading by diverse anthropogenic activities. Understanding the present condition of groundwater environment and water budget is necessary to prevent natural and manmade disasters and to prepare for sustainable water resource management of urban environment. In this study, regional groundwater flow and water budget status of Seoul was analyzed using numerical simulation. Modeling result indicated that groundwater level distribution of Seoul generally followed the topography, but the significant decreases in groundwater level were observed around the subway network. Steady-state water balance analysis showed groundwater recharge by rainfall and leakage from the water supply network was about 550,495 m³/day. Surface water inflow and baseflow rate via Han River and major streams accounted for 799,689 m³/day and 1,103,906 m³/day, respectively. Groundwater usage was 60,945 m³/day, and the total groundwater leakage along the subway lines amounted to 114,746 m³/day. Modeling results revealed that the subway could decrease net groundwater baseflow by 40%. Our study result demonstrated that the subway system can have a significant influence on the groundwater environment of Seoul.

• Applied Biological Chemistry
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• 제40권5호
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• pp.409-415
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• 1997

식품 및 배합사료 첨가제로서 치아민 모노유도체인 치아민 모노로단염이외, 치아민 모노요오드염 치아민 모노브름염 등의 3종류의 용해도를 $40,{\;}50,{\;}60^{\circ}C$에서 구하였고 그 온도에서 4수준(0.5, 1.0, 2.5, 5.0 w/w%)의 물을 첨가한 다음 경시적으로 겉보기 착색속도정수(ka)를 산출하였다. 그리고 산제이외 제제에 대하여는 착색도 가능성을 검토할 목적으로 비교적 조성이 간단한 과립, 정제를 만들어 이것에 3수준(0.5, 1.0, 2.5 w/w%)의 물을 첨가한 후 산제와 동일한 온도에서 경시적으로 착색시험으로부터 ka를 산출하였고, 구배 ka인 직선에 대하여는 회귀분산을 이용하여 직선성의 검정을 행하였다. 실험 범위 내에서는 위험률 5%수준에서 모두 유의한 결과를 얻었다. 과립 및 정제의 착색변화로부터 얻은 ka와 1/T간에 직선적인 관계가 성립하여 Arrhenius식을 만족시켰다.

• BMB Reports
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• 제42권4호
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• pp.223-226
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• 2009

We measured the pH-induced spectral changes of yeast iso-1-cytochrome c on silver nanoparticle surfaces using surface-enhanced resonance Raman scattering (SERRS) at 457.9 nm. At a pH of ~3, the Met80 ligand in yeast iso-1-cytochrome c is assumed to dissociate, leading to a marked conformational change as evidenced by the vibrational spectral shifts. The Soret band at ~410 nm in the UV-Vis spectrum shifted to ~396 nm at pH~3, indicating a transition from a low spin state to a high spin state from a weak interaction with a water molecule. Thus, SERRS spectroscopy can measure the pH-induced denaturalization of cyt c adsorbed on metal nanoparticle surfaces at a lower concentration with a better sensitivity than ordinary resonance Raman spectroscopy.

• Journal of Ecology and Environment
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• 제38권1호
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• pp.95-107
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• 2015

Because an ecological community consists of diverse species that vary nonlinearly with environmental variability, its dynamics are complex and difficult to analyze. To investigate temporal variations of benthic macroinvertebrate community, we used the community data that were collected at the sampling site in Baenae Stream near Busan, Korea, which is a clean stream with minimum pollution, from July 2006 to July 2013. First, we used a self-organizing map (SOM) to heuristically derive the states that characterizes the biotic condition of the benthic macroinvertebrate communities in forms of time series data. Next, we applied the hidden Markov model (HMM) to fine-tune the states objectively and to obtain the transition probabilities between the states and the emission probabilities that show the connection of the states with observable events such as the number of species, the diversity measured by Shannon entropy, and the biological water quality index (BMWP). While the number of species apparently addressed the state of the community, the diversity reflected the state changes after the HMM training along with seasonal variations in cyclic manners. The BMWP showed clear characterization of events that correspond to the different states based on the emission probabilities. The environmental factors such as temperature and precipitation also indicated the seasonal and cyclic changes according to the HMM. Though the usage of the HMM alone can guarantee the convergence of the training or the precision of the derived states based on field data in this study, the derivation of the states by the SOM that followed the fine-tuning by the HMM well elucidated the states of the community and could serve as an alternative reference system to reveal the ecological structures in stream communities.

• Journal of Ecology and Environment
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• 제33권4호
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• pp.289-298
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• 2010

A number of characteristics of the Lake H$\ddot{o}$vsg$\ddot{o}$l watershed, such as the lake's location at the edge of the Central Asian continuous permafrost zone, provide a unique opportunity to evaluate possible anthropogenic impacts in this remote area in northern Mongolia. In this study, we compared stream solute concentrations in six sub-watersheds in the Lake H$\ddot{o}$vsg$\ddot{o}$l watershed. Water samples were collected during the summer months between 2003 and 2005. Concentrations of $Cl^-$ ranged from 9.8 to $51.3\;{\mu}mol/L$; average nitrate concentrations were very low and ranged from undetectable to $1.1\;{\mu}mol/L$ and average ${SO_4}^{2-}$ concentration at sampling stations with minimal animal grazing ranged from 66 to $294\;{\mu}mol/L$. Average dissolved organic carbon (DOC) concentrations ranged from 642 to $1,180\;{\mu}mol$ C/L. We did not find statistically significant differences in DOC concentrations among the six streams, although DOC concentrations tended to be higher in the two northernmost streams, possibly related to differences in the active layer above the permafrost. Dissolved organic nitrogen (DON) concentrations were correlated with DOC concentration, and followed the same spatial pattern as those for DOC. In streams in this remote watershed, total dissolved nitrogen was made up of mostly organic N, as has been found for other regions distant from anthropogenic N sources. Overall, these results suggest that future research on the dynamics of DOC and DON in this watershed will be especially insightful in helping to understand how changes in climate and land use patterns will affect transformations, retention, and export of dissolved organic matter within these sub-watersheds in the Lake H$\ddot{o}$vsg$\ddot{o}$l region.

• 대한화학회지
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• 제53권6호
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• pp.784-792
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• 2009

본 연구는 과학 교사들의 과학과 교수 . 학습 설계 시 도움이 되는 자료를 제공하기 위하여 각 시-도 교수학습지원센터와 서울특별시과학전시관 홈페이지에 게재되어 있는 교수-학습 과정안에 나타나는 교육과정 위계 부적합 사례를 조사하였다. 교육과정 위계 부적합 사례는 7학년 ‘물질의 세 가지 상태’ 단원에 한정하였으며, 분석에 사용한 내용 요소는 물질의 상태 변화, 분자, 분자 모형이었다. 그 결과 교육과정 위계 부적합 사례에 해당하는 내용 요소는 ‘물질의 상태 변화’에서는 플라즈마, 상평형, 눈이 생기는 현상, 물의 특이성, 결정성과 비결정성 고체의 분류, 열에너지, 물리 변화 등 7종류였으며, ‘분자 모형’에서는 분자 운동, 밀도가 발견되었다. 그리고 ‘분자’에서는 교육과정 위계 부적합 사례가 발견되지 않았다.