• 생명과학회지
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• 제17권10호
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• pp.1414-1418
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• 2007

3가지 농도의 납을 첨가한 토양에서 생장한 애기장대(Arabidopsis thaliana)에서 식물체에 축적된 납의 농도를 조사하였다. 환경부 고시 오염물질 배출기준 농도(1 mg/l)와 10배 높은 농도(10 mg/l) 및 50배 높은 농도(50 mg/l)의 납이 첨가된 토양에서 생장한 식물의 줄기에 축적된 납의 농도는 3가지 농도에서 증가율이 유사하게 나타났으며, 정상식물 줄기에 비하여 평균 약 24% 증가하였다. 3가지 농도의 납이 첨가된 토양에서 생장한 식물의 잎에 축적된 납의 농도는 정상식물 잎에 비하여 평균 약 57% 증가하였으며, 줄기와 마찬가지로 토양에 첨가된 납의 농도 증가에 따라 잎에 축적된 납의 농도는 유의한 차이는 나타나지 않았으며 증가율도 유사하였다. 반면 오염물질 배출기준 농도와 10배 높은 농도의 납이 첨가된 토양에서 생장한 식물의 뿌리에 축적된 납의 농도는 정상식물 뿌리에 비하여 평균 약 114% 증가하였으나, 50배 높은 농도에서는 약 861% 증가하여 줄기나 잎과는 대조적인 결과를 나타내었다. 토양 속에 첨가된 납의 농도가 증가하면 애기장대 식물체 내에 축적된 납의 농도도 증가하였는데, 특히 오염물질 배출기준농도보다 50배 높은 납이 첨가된 토양에서 생장한 식물체내에 축적된 납 농도는 정상식물보다 약 2.6배 증가하였다. 이러한 결과는 토양 속에 오염된 납은 식물의 줄기나 잎보다는 뿌리에 더 많이 축적되며, 줄기와 잎에 축적되는 납 농도는 토양 속에 오염된 납 농도에 비례하여 증가하지 않으나 뿌리에서는 농도에 비례하여 매우 증가하였음을 나타내고 있다.

• 아동학회지
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• 제37권3호
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• pp.1-12
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• 2016

Objective: This study aimed to examine the difference in toddlers' accumulated cortisol levels based on childcare experience in toddlerhood and the relationship between temperament and accumulated cortisol levels. Methods: Hair sample were collected for measure accumulated cortisol level in 87 toddlers. The Early Childhood Behavior Questionnaire (ECBQ) was used to measure temperament. Results: First, toddlers in childcare showed higher accumulated cortisol levels than in-home toddlers. Second, toddlers in childcare, exhibited a significant correlation between accumulated cortisol levels and surgency. Third, the accumulated cortisol levels of in-home toddlers exhibited a significant correlation with negative affect. In this research, there was significant range in the accumulated cortisol level according to childcare use, and the factors related to accumulated cortisol levels were different in each context. Conclusion: The results of this research support the "susceptibility to context of HPA axis" and imply a needed discussion about the effect of childcare experiences in toddlerhood.

• 한국환경과학회지
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• 제17권9호
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• pp.1015-1021
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• 2008

This study was performed to examine the accumulated concentrations (conc.) of cadmium (Cd) in the organs of Arabidopsis thaliana grown in the soil with different conc. of Cd. The official standard conc. of Cd of pollutant exhaust notified by the Korean ministry of environment (0.1 mg/L) and ten times higher (1 mg/L) and fifty times higher (5 mg/L) conc. and no Cd in the soil as control were used for this investigation. The results showed that accumulated conc. of Cd in the stems of plant grown in the soil with different conc. (0.1, 1 and 5 mg/L) were increased 9%, 24% and 286% respectively, compared with normal plant stem. The accumulated conc. of Cd in the leafs of plant gown in the soil with official standard conc. and conc. ten times higher and conc. fifty times higher were increased 3%, 22% and 453%, respectively, compared with normal plant leaf. The accumulated conc. of Cd in the root of plant grown in the soil with 0.1 and 1 mg/L conc. of Cd were increased 6%, 19%, respectively, compared with normal plant root. However, it was observed about 84% of increased accumulation of the Cd in the root of plant, when highest (5 mg/L) conc. was used. The accumulated conc. of Cd in the different organs of Arabidopsis thaliana were increased according to increase of Cd conc. in the soil. When official standard conc. and ten times higher conc. of Cd were used, the accumulated conc. of Cd increased average 6%, 21%, respectively, compared with normal plant organ, and the accumulated conc. of Cd between leaf, stem and root were not significant. However, the accumulated conc. of Cd in the plant organs gown in the conc. fifty times higher were increased about 285%, compared with normal plant. In addition, the accumulated conc. of Cd in different organs of Arabidopsis thaliana exhibited wide differences between organs, that is, stem was increased 118% than root, leaf was increased 256%, 64% than root and stem, respectively. These results show that accumulated conc. of Cd in Arabidopsis thaliana with highest (5 mg/L) conc. of Cd in soil, were much higher in the leaf than the stem or root in proportion to the conc. of Cd contaminated within the soil.

• 오토저널
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• 제10권5호
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• pp.54-60
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• 1988

This study is a theoretical analysis and experimental effect of oxygen concentration, exhaust velocity and trap inlet temperature on particulate ignition temperature with installation of ceramic filter trap in diesel engine. So the following results are obtained. 1, Based on the fundamental experiments of the regeneration process, the analytical model was developed and the results from the analytical model agreed with the experiments, then the validity of the model was proved. 2, The ignition temperature for accumulated particulate was proportional to the exhaust velocity and it was known that the optimum exhaust velocity was about 15m/sec. 3, The ignition temperature for accumulated particulate was inversely proportional to the oxygen concentration and the trap inlet temperature, and a minimum oxygen concentration of 5% was required to sustain regeneration. 4, This experimental filter trap(EX-66) is found about 30% of smoke reduction efficiency in comparison with existing muffler.

• 한국미생물·생명공학회지
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• 제24권5호
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• pp.597-603
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• 1996

This study was carried out to examine degradation characteristics of microalgae Chlorella vulgaris in methane fermentation. We measured COD and VS reduction, gas and methane productivity, VFA (volatile fatty acid), respectively. Then we calculated material balance and hydrolysis rates in soluble and solid material. The substrate concentration was controlled from 14 gCOD$_{cr}$/l to 64 gCOD$_{cr}$/l in batch cultures, and HRT (hydraulic retention time) controlled from 2 days to 30 days in continuous experi- ments. The results were as follows. In batch culture, accumulated gas productivity increased with the increase of the substrate concentration. The SS and VSS was removed all about 30% increase of substrate concentration and the most of the degradable material removed during the first 10 days. The curve of gas and methane production rate straightly increased until substrate concentration is 26 gCOD$_{cr}$/l. In continuous culture experiments, the removal rates at HRT 10days were 20% for total COD and TOC, respectively. At longer HRT, there was no increase in the removal efficiency. At HRT 15 days, the removal rates were 30% for SS and VSS, respectively. Soluble organic materials were rapidly degraded, and so there was no accumulated. Soluble COD concentration was not increase regardless of HRT-increasing. That meaned the hydrolysis was one of the rate-limiting stage of methane fermentation. The first-order rate constants of hydrolysis were 0.23-0.28 day$^{-1}$ for VSS, and 0.07-0.08 day$^{-1}$ for COD.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권3호
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• pp.61-68
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• 2010

Phytoextraction, one type of phytoremediation processes, has been widely used in the removal of heavy metals from polluted soil. This paper reviewed literature on metal uptake by plants and characterized the metal uptake by types of metals (Zn, Cu, Pb, Cd, and As), plant species, initial metal concentrations in soil and the distribution of metals in different parts of plants. The potential of metal accumulation and transport by plants was closely related to plants species, types of metals, and initial metal concentrations in soil. The plants belonging to Brassicaceae, Solanaceae, Poaceae, and Convolvulaceae families have shown the high potential capacity of Cd accumulation. The Gentianaceae, Euphorbiaceae, and Polygonaceae families have exhibited relatively high Pb uptake potential while the Pteridaceae and Cyperaceae families have shown relatively high Zn uptake potential. The Pteridaceae family could uptake a remarkably high amount of As compared with other plant families. The potential metal accumulation per plant biomass has increased with increasing initial metal concentration in soil up to a certain level and then decreased for Cd and Zn. For As, only Pteris vittata had a linear relationship between initial concentration in soil and potential of metal uptake. However, a meaningful relationship for Pb was not found in this study. Generally, the plants having high metal uptake potential for Cd or Pb mainly accumulated the metal in their roots. However, the Euphorbiaceae family has accumulated more than 80% of Pb in shoot. Zn has evenly accumulated in roots and stems except for the plants belonging to the Polygonaceae and Rosaceae families which accumulated Zn in their leaves. The Pteridaceae family has accumulated a higher amount of As in leaves than roots. The types of metals, plant species, and initial metal concentration in soil influence the metal uptake by plants. It is important to select site-specific plant species for effective removal of metals in soil. Therefore, this study may provide useful and beneficial information on metal accumulation by plants for the in situ phytoremediation.

• Journal of the korean society of oceanography
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• 제39권3호
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• pp.197-206
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• 2004

Mussel, Mytilus galloprovincialis, was transplanted reciprocally between contaminated site (St. STP) and relatively less contaminated site (St. UB) in Onsan Bay, Korea in order to estimate heavy metal accumulation and release. Transplanted and indigenous mussels were collected 8 times over 108 days deployment at both sites and analyzed for Cd, Cu, Pb and Zn using ICP/MS. Cu and Zn concentration did not show any significant differences between transplanted and indigenous mussels throughout the experiment period, although dissolved Cu and Zn concentrations in seawater were significantly higher at contaminated site. Pb accumulated rapidly, while Cd did not show any accumulation in the mussels transplanted from St. UB to St. STP. These accumulation patterns might reflect the variation of dissolved metal concentration; dissolved Pb concentration was significantly higher in St. STP than St. UB, while dissolved Cd concentration was similar between both sites throughout this experiment. Release of Cd and Pb in the mussels transplanted from St. STP to St. UB was not significant during the transplantation period. The levels and variation of Pb and Cd concentrations in mussels transplanted from St. STP to St. UB were similar to those in the indigenous mussels at St. STP throughout the period. Therefore, Cd and Pb accumulated in indigenous mussels may indicate the integrated metals throughout their lives, not responding to the present status of seawater because the release of accumulated metals in mussels occurs very slowly when the seawater metal levels are lowered. On the other hand, since the transplanted mussels can respond immediately to the levels of metals in seawater, it may be suggested that the present status of heavy metals in seawater can be only acquired from the metal levels of mussels transplanted from clean environments.

• 한국산림과학회지
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• 제99권3호
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• pp.292-297
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• 2010

본 연구는 Ni 오염지를 정화하기 위한 기초자료를 제공하고자 Ni 수용액에서 Salix reichardtii를 수경재배 한 후 수용액의 pH 변화와 부위별 Ni 축적량을 분석하여 다음과 같은 결과를 얻었다. 영양액의 pH는 Ni의 처리농도가 낮아 S. reichardtii의 생장속도가 높을수록 많이 낮아졌고 Ni의 농도가 높아 생장속도가 저조할수록 적게 낮아졌다. 부위별 Ni의 축적량은 뿌리가 가장 높고 다음이 잎, 줄기의 순이었으며 오래된 줄기 내 축적량이 가장 낮았다. 즉, 식물체의 조직이 유연하고 생활세포가 많을수록 Ni축적량이 많은 것으로 나타났다. 또한 Ni의 처리 50 ${\mu}mol$/L까지 는 농도가 높아질수록 체내 축적량은 높아졌으나 100.0 ${\mu}mol$/L처리구에서는 식물체가 고사되어 체내 축적량이 오히려 감소되는 경향이었다. Ni가 농도별로 함유된 영양액에서 수경재배 한 결과 Ni를 고농도로 처리할수록 S. reichardtii의 생장은 저조하였으며, Ni 100.0 ${\mu}mol$/L처리구에서는 4주후 거의 고사수준이었다.

• 생명과학회지
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• 제29권8호
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• pp.879-887
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• 2019

본 연구에서는 생쥐 신장, 간, 비장 내 축적된 수은의 위치와 아울러서 시간에 따른 수은 농도 변화를 조사하였다. 수은 투여 종료 후 10일, 150일, 300일에 생쥐를 희생하여 수은 농도변화를 분석하였다. 10일에 희생시킨 생쥐 신장의 경우, 근위세뇨관 상피세포의 핵 위쪽 세포질에 수은이 다량으로 분포하였으나, 사구체에는 분포하지 않았다. 간의 경우, 수은이 주로 간문맥 주위에 있는 간세포와 굴모세혈관에 있는 Kupffer 세포에 분포하였다. 10일에 희생시킨 비장의 경우, 백색 수질과 적색 수질에 수은이 흩어져 분포하였다. 수은의 농도 변화에 있어서, 150일과 300일에 희생시킨 신장의 피질과 수질에 축적되어 있던 수은이 낮은 농도로 나타났다. 역시 간세포에 축적되어 있던 수은도 150일과 300일의 경우, 낮은 농도로 나타났다. 비장의 경우, 백수와 적수 조직에 있던 수은 농도가 감소되었다. 이런 결과를 통해 세포나 조직에 축적되어 있던 수은의 위치가 확인되었으며, 또한 이 결과는 기관에 축적되어 있던 수은 농도가 시간이 지남에 따라 자연스럽게 감소된다는 사실을 확인해 주고 있다.

• The Korean Journal of Ecology
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• 제27권4호
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• pp.193-198
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• 2004

본 연구는 우리나라 영종도와 삼목도에 도래하는 섭금류(Shorebirds)의 간과 신장에서 중금속 축적에 대한 연구이다. 아연의 농도는 영종도의 큰뒷부리도요의 간과 신장에서 각각 76.7 ㎍/wet g, 65.8 ㎍/wet g으로서 가장 높은 농도를 보였다. 망간의 경우, 간에서 가장 높은 농도는 4.68㎍/wet g을 나타낸 영종도의 청다리도요였고, 신장에서는 삼목도의 흰물떼새에서 18.61㎍/wet g으로 가장 높았다. 구리농도는 영종도 큰뒷부리도요의 간과 신장에서 각각 25.4 ㎍/wet g과 44.1 ㎍/wet g으로 가장 높았다. 납 농도가 가장 농도가 높게 나타난 종은 삼목도의 좀도요로서 간에서 17.0 ㎍/wet g, 신장에서 40.2 ㎍/wet g이었다. 그리고 납 농도는 모든 종에서 신장에서의 농도가 간에서의 농도보다 높게 나타났다. 간에서 카드뮴 농도는 0.73±0.26㎍/wet g을 나타낸 영종도의 민물도요에서 가장 높았고, 신장에서는 영종도의 흰물떼새에서 4.89±1.49 ㎍/wet g으로 가장 높았다. 카드뮴은 모든 종에서 간보다는 신장에서 농도가 높았다. 그리고 간과 신장에서의 납과 카드뮴 농도는 붉은어깨도요를 제외하고는 영종도에서의 농도가 삼목도보다 높았다.