• 한국물환경학회지
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• 제21권6호
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• pp.602-608
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• 2005

A laboratory-scale experiment was conducted to investigate control of soluble microbial products (SMP) by the internal recycle rate in the submerged membrane separation activated sludge process. The internal recycle rate of the reactor RUN 1 and RUN 2 were 100 % and 200 %, respectively. SMP concentration was rapidly accumulated in the reactor (RUN 1). The variation of accumulated SMP concentration was related to the denitrification rate at the beginning experiment however SMP concentration decreased without correlatively to the denitrification rate during long operation time. The microbial kinetic model was rapidly presented in the both microbial growth and extinction in the reactor (RUN 1). In the SMP kinetic model, Internal recycle rate is the lower, value of UAP and BAP which SMP matter were presented low. The study about development of kinetic model is relatively well adjusted to the experiment exception SMP. In the future, SMP formation equation must be thought that continually research is necessary.

• 한국산림과학회지
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• 제90권4호
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• pp.495-504
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• 2001

본 연구는 포플러 4개 수종의 체내 부위별 Cd과 Pb 축적 특성을 이해하고, 균근 형성이 중금속 흡수에 미치는 영향을 밝히고자 수행하였다. 외생균근균인 모래밭버섯균(Pisolithus tinctorius)을 현사시나무(Populus alba${\times}$glandulosa), 수원포플러(P. koreana${\times}$nigra var. italica), 양황철(P. nigra${\times}$maximowiczii), 이태리포플러(P. euramericana)의 삽수에 접종하여 화분에서 생장시켰다. 화분은 균근균 접종구와 비접종구로 구분하였으며, Cd은 토양에 0, 30, 80ppm으로, 그리고 Pb은 0, 50, 300ppm으로 처리하였다. 가을까지 야외에서 생육시킨 다음, 수확 후 총 생체량, Shoot/Root율, Cd과 Pb의 농도를 부위별로 측정하였다. 모래밭버섯균을 접종한 이태리포플러는 Cd과 Pb 처리 모두에서 비접종구보다 총 생체량이 증가하였으나, 나머지 세 수종에서는 접종 효과가 없었다. 균근균 접종으로 수원포플러와 이태리포플러의 S/R율은 증가하였다. 현사시나무는 포플러 4개 수종 중 Cd을 가장 높은 농도로 축적하였으며, 균근균 접종은 Cd 축적 농도를 4배정도 증가시켰다. 현사시나무는 잎, 줄기, 뿌리 중에서 잎에 가장 높은 농도로 Cd을 축적한 반면 다른 세 수종은 뿌리에 가장 높은 농도로 축적하였다. 그러나 Pb 축적 농도는 4개 수종 중에서 현사시나무가 가장 낮았다. Pb의 축적은 포플러 4개 수종모두뿌리에서 가장 높았으나 수원포플러는 잎에도 뿌리만큼 축적하였다. 균근균을 접종하지 않은 경우 Pb의 축적은 이태리포플러에서 가장 높았으나, 균근균을 접종할 경우 수원포플러에서 Pb 축적이 2배 이상 증가하였다. 결론적으로 현사시나무는 토양으로부터 Cd을 흡수하는데 효과적인 수종이며 이태리포플러는 Pb을 효과적으로 흡수한다. 균근균을 접종하면 현사시나무의 경우 Cd을 4배, 수원포플러의 경우 Pb을 2배 이상 더 흡수할 수 있고, 이 두 수종은 잎에 중금속을 축적하므로, 낙엽을 수거한다면 중금속 오염 토양의 생물 정화용으로 이용이 가능하다고 결론 짓는다.

• 한국토양비료학회지
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• 제40권4호
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• pp.298-310
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• 2007

본 연구는 동판 건물 주변의 구리 오염 토양과 지렁이를 이용해 microcosm soil test를 실시함으로써 지렁이 체내에 농축된 구리 농도와 몇 가지의 토양 내 중금속 침출 방법으로 측정한 토양 내 구리 농도간의 상관관계를 비교하기 위하여 수행하였다. 조사 지역의 토양 시료를 이용해 control, 1C(Contamination level, 최저 처리 농도), 2C, 4C, 8C, 16C(최고 처리 농도)의 여섯 가지 처리구를 통해 microcosm soil test를 실시한 결과, 토양 내 구리의 농도와 실험 기간이 경과함에 따라 지렁이의 생장량과 지렁이 체내 농축 구리 농도가 함께 증가하는 것으로 조사되었으며, 그 정도는 microcosm 내 토양의 구리 처리 농도와 같은 순서였다. 토양 내 구리 농도를 조사하기 위해 공정시험법을 사용하였고 토양 내 구리 총함량을 조사하기 위해 EPA 3051 방법을 사용하였다. 공정시험법으로 침출한 토양 내 구리 농도와 토양 내 구리 총함량간의 상관계수(r)는 0.9875~0.9993로 고도의 정의 상관관계가 존재하였다. 위의 두 결과와 지렁이 체내에 농축된 구리 농도와의 상관관계를 비교해 본 결과, 공정시험법으로 침출한 토양 내 구리 농도와 지렁이 체내 농축 구리 농도간의 상관계수와 토양 내 구리 총함량과 지렁이 체내 농축 구리 농도간의 상관계수는 각각 0.9193~0.9728과 0.9282~0.9844로 고도의 정의 상관관계를 나타내었다. 토양 내 구리 농도와 지렁이 체내 농축 구리 농도 간에 상당히 높은 수준의 상관관계를 보임에 따라 지렁이는 토양 내 구리 오염에 대한 유용한 생물지표종(biological indicator species) 또는 생물모니터링(biomonitoring)에 적합한 종의 역할을 할 수 있을 것이라 판단하였다.

• Journal of Nutrition and Health
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• 제27권8호
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• pp.828-836
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• 1994

A low level exposure experiment was conducted on growing rats to investigate the accumulation and organ distribution of protein bound cadmium compared with cadmium chloride. Male Sprague-Dawley rats were fed for 21days with one of the semisynthetic diets, which contains cadmium as either bovine liver- or kidney meal bound cadmium, cadmium chloride with uncontaminated liver meal or cadmium chloride without organ meal, in the levels of ca. 0.5, 1 and 1.5mg/kg diet, respectively. After 21days of exposure cadmium was accumulated in liver, kidney and gastrointestinal tracts depending upon cadmium levels in diet. Inspite of very low cadmium accumulation in whole blood, it tends also to increase with dietary cadmium levels. The blood cadmium concentration of animals fed organ meal containing diets was about 4-7 fold higher than that without organ meal, regardless of cadmium was intrinsically bound to protein or not. However, significant effects of organ protein on cadmium accumulation in liver, kidney and digestive tracts were not detectable, when cadmium was supplemented as cadmium chloride. On the other hands, animals fed diet containing ca. 1.5mg Cd/kg as organ bound cadmium retained more cadmium in liver, kidney and digestive tracts compared to cadmium chloride with organ meal, whereby the increase of cadmium concentration in kidney was greater then in liver. However, when the concentration of protein bound cadmium was<1mg/kg diet, organ bound cadmium was not significantly different from cadmium chloride in bioavailability and organ distribution. From this result it is suggested that the intestinal absorption of protein bound cadmium is influenced of the amount of cadmium bound in protein. When cadmium concentration in protein is relatively low, protein bound cadmium seems to be absorbed in the same way as cadmium ions are absorbed. However, when the concentration is high, at least a small amount of intact protein bound cadmium could be absorbed and accumulated selectively in kidney.

• Journal of the Korean Physical Society
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• 제73권12호
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• pp.1899-1903
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• 2018

The effects of introducing hybrid lipids to a lipid bilayer containing saturated and unsaturated lipids immersed in water were studied. The lipid and water molecules were modeled as coarse-grained particles. All particles were simulated by using the dissipative particle dynamics method. The results showed that the hybrid lipids accumulated at the interface between the saturated and the unsaturated lipid domains. The relation between the hybrid lipid concentration and the equilibrium domain size was obtained. Moreover, the sizes of the simulated lipid domains are consistent with that given by the lipid raft definition.

• Journal of Pharmaceutical Investigation
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• 제32권4호
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• pp.291-297
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• 2002

For preventing and curing the stretching mark, TECA Niosome/W/O system creams were formulated using Titrated Extract of Centella Asiatica (TECA) which is well known for its excellent wound healing effect. The lipid-water partition coefficients and the stabilities of TECA were evaluated and TECA Niosome/W/O system (TECA N/W/O) creams were prepared with different concentrations of cetyl alcohol and ceramide. TECA N/W/O cream was evaluated with respect to their rheological properties, permeation through excised skin of hairless mouse and in vitro and in vivo accumulation in the skin of hairless mouse. In addition, dermal thicknesses of hairless mouse skins were determined following the in vivo application of TECA N/W/O cream and control cream. TECA N/W/O creams showed pseudoplastic flow and hysteresis loop. The permeation of TECA from formulations through excised skin of hairless mouse did not observed. Amount of accumulated drug in the excised skin of hairless mouse was deσeased with an increase in the concentration of cetyl alcohol and showed no relationship with concentration of ceramide. Amount of accumulated drug in formulation A-3 was higher than in niosome suspension and other formulations. In in vivo experiment, amount of accumulated drug in formulation A-2 and A-3 was much higher than that of niosome suspension. Being treated with the N/W/O cream for 8 weeks, the dermal thickness of hairless mouse skin was increased 3.2 times than that of 16 weeks-control group.

• 한국환경과학회지
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• 제23권1호
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• pp.61-68
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• 2014

This study attempted to utilize various groundcover plants in phytoremediation, using shade plants, which often have a high shade tolerance for shade urban space. Liriope platyphylla was grown in soil containing three of heavy metals, Zn, Cd, and Pb under four different concentrations (0, 100, 250 and 500 mg/kg) to determine the heavy metal accumulation characteristics and removing from soil. Total amounts of accumulated Zn in L. platyphylla were increased in accordance with increasing elevated Zn concentrations in soil, but the difference was not significant between Zn250 and Zn500. Cd accumulation, sharply increased in Cd100 and Cd250, but was reduced in Cd500. Increased Pb concentration in soil resulted a continuous increase in the total amounts of Pb accumulated in L. platyphylla. The total content of Zn in soil decreased by almost 50% in Zn100, almost 33% in Zn250 and 20% in Zn500 through growth of L. platyphylla over a period of 7 months. In the case of Cd, the concentration in soil, was decreased with 10% in Cd100, 10% in Cd250 and 33% in Cd500 through growth of L. platyphylla over a period of 7 months. This results indicate that more Cd was removed by planting L. platyphylla, compared to Zn or Pb.

• 한국환경과학회지
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• 제13권12호
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• pp.1103-1108
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• 2004

This experiment was carried out to investigate the effects of cadmium on the growth of Arabidopsis thaliana when they were treated with different concentrations of cadmium. The growth of stem was stimulated in the concentrations up to fifty times higher than the official standard concentration of cadmium of pollutant exhaust notified by the Ministry of Environment, but it decreased in the concentration one hundred fifty times or more higher in proportion to the degree of concentration. The growth of root was similar to that of stem, except that the decrease was gradual in the concentration fifty times or more higher. The growth of leaf was almost the same as that of stem, that is, it was stimulated the increase of leaf surface area in the concentration fifty times higher, but decreased in the concentration one hundred fifty times or more higher in proportion to the degree of concentration. The fresh weights of the plants were increased in accord with the degree of growth of the stem and leaf. Concentration of cadmium accumulated in the plants was increased in proportion to the concentration of cadmium. These results show that the growth of plants was stimulated in the soil polluted by cadmium up to fifty times higher than the official standard concentration, but it was decreased in proportion to the degree of concentration in the plants grown in the presence of cadmium more than one hundred fifty times.

• 한국환경과학회지
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• 제15권4호
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• pp.359-364
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• 2006

Two sites with different average daily traffic volume at an intersection were selected in order to investigate water quality of the first flushes in the surface runoffs. The effects of rainfall intensities and accumulated non-rainy days before rainfall events on the water quality were also delineated. Samples were collected at every 2 min. interval from each first flush from February to May, 2004 for 4 major rainfall events. $COD_{cr}$ or SS concentrations at the site with an average daily traffic volume (ADTV) of 23,000 vehicles were 2-7 times higher than those at the site with an ADTV of 1,400 vehicles. The longer the accumulated non-rainy days were, the higher the concentration of heavy metals were than those of $COD_{cr}$ and SS in the first flushes.

• ALGAE
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• 제18권4호
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• pp.349-354
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• 2003

This paper reports that the heavy metal accumulation in marine seaweeds. Algal samples collected from Korean coast were analyzed to determine the concentrations of Cu, Cd, Cr, Zn and Pb. In general, heavy metals were found to be concentrated in many kinds of Korean seaweeds. The concentration levels of accumulated heavy metals in the marine seaweeds was in the following order: Zn > Cu > Cr > Pb > Cd. The concentrations of the heavy metals in the seawater were the highest in Iyajin harbor. Sargassum horneri, a brown alga accumulated high concentrations of Cu (80.66 ${\mu}g{\cdot}g^{-1}$ dw) and Cr (31.54 ${\mu}g{\cdot}g^{-1}$ dw). The high concentrations of heavy metals were accumulated in the brown algae.