• 한국환경과학회지
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• 제5권6호
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• pp.801-812
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• 1996

We investigated concentrations of heavy metals(Cr, Cd, Zn, Fe, Pb, Cu, and Mnl and correlations between concentrations of heavy metals in the sediment, soil, weeds, and vegetables on the lower Nakdong river. Concentrations of heavy metals on the lower Milyang river was generally lower than those of other sampling area. In the soil, concentration of Pb is generally larger than that of other heavy metals. Generally, concentrations of heavy metals in the sediment show decreasing tendency 8s the sampling area moves toward downstream of the river, but those of in the soil and weeds show increasing tendency. There is no significant correlation between concentration of heavy metals in the soil-sediment, soil-vegetables, sediment-weeds, or vegetables-weeds. Only concentrations of Pb in the vegetables and those of in the weeds show very high correlation.

• 한국환경과학회지
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• 제13권8호
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• pp.739-746
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• 2004

Concentrations of PCBs in the sediment of the Kumho River was determined. Samples were collected at 23 locations along the river. Total PCB levels ranged from 2.7 to 87.6 ng/g dry weight. The site near the Keomdan factory district had the highest concentrations. The levels of PCB congeners significantly correlated with the total organic carbons in the sediment. The major fractions of PCBs were congeners containing 4, 5, or 6 chlorine atoms per biphenyl molecule.

• 한국토양비료학회지
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• 제50권4호
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• pp.285-292
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• 2017

Antibiotics have been used for treating human and animal disease and enhancing growth of cattle, swine, and poultries. However, overused antibiotics can be released into the environment and produce antibiotic resistance genes (ARGs) in the environment. Main objective of this research was to monitor residual of antibiotics in solid matrix such as manure, wastewater sludge, soil and sediment. Total of six antibiotics, Chlortetracycline (CTC), Oxytetracycline (OTC), Tetracycline (TC), Sulfamethazine (SMT), Sulfamethoxazole (SMX), Sulfathiazole (STZ), used for both human and animal was monitored. Result showed that the detection frequency of 6 antibiotics was ordered SMT (100%) > TC = CTC (75%) > OTC (38%) > STZ (13%) > SMZ (0%) and the highest concentration ($309.83{\mu}g\;kg^{-1}$, SMT) was observed in manure. Comparing residual concentration of antibiotics (TC, CTC, and OTC) in soil and sediment, higher concentration was observed in sediment indicating that dissolved forms of antibiotics are released into river and sorbed into sediment particle. In conclusion, monitoring for residual of antibiotics in the environment is necessary and more research should be conducted to verify the source of antibiotic release.

• 농촌계획
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• 제11권4호
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• pp.25-31
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• 2005

The present study was carried out to investigate the P fractions of surfical sediment of Dongjin sea area. Furthermore, potential released loading of adsorbed and non-apatite inorganic phosphorus were investigated in the sediment of Dongjin sea area. The contents of phosphorus fractions of the surficial sediment in Dongjin sea area were adsorbed-P 0.06%, nonapatite inorganic-P 13.02%, apatite-P 60.22%, and residual-P 26.70%. The most abundant fraction was apatite-P, residual-P, nonapatite inorganic-P, and adsorbed-P followed it. Potential released loading of adsorbed and non-apatite inorganic phosphorus surveyed 2.6 and 597ton respectively. These results show that sediment-managing and interception from external pollution are needed for water environmental maintenance of Dongjin sea area.

• The Korean Journal of Ecology
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• 제28권5호
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• pp.245-254
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• 2005

This paper presents a paleoenvironmental study on Hoya Rincon do Parangueo, a maar lake in Valle de Santiago in Central Mexican Bajio. Maar lake sediments have been widely used for high-resolution reconstruction of paleoenvironment. Many different paleoenvironmental proxy data such as stable isotopes, pollen, sediment chemistry, and dung fungus spore were produced in this study. The pine-oak ratio, stable isotopes, and sediment chemistry help to reveal paleoenviromental changes throughout the whole period covered by sediment materials from this study site. The evidence I found indicates that during ca. 9,500 $\sim$ ca. 8,300 cal yr B.P. there was dry climate; during ca. 8,300 $\sim$ ca. 6,300 cal yr B.P. it was wetter; during ca. 6,300 $\sim$ ca. 4,000 cal yr B.P. drier and cooler; during ca. 4,000 $\sim$ ca. 1,100 cal yr B.P. milder and wetter. The presence of Chupicuaro culture between ca. 2,500 $\sim$ 1,100 cal yr B.P. is implied by the high frequencies of Amaranthaceae and Zea mars. It seems that man left this lake around 1,100 cal yr B.P. due to a dry climate after 1,300 cal yr B.P. Spanish arrival around 400 cal yr B.P. is implied by the fact that fe3 mars reappears and Sporormiella spp. become significant around 120 cm, whereas Poaceae drops sharply.

• Natural Product Sciences
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• 제21권4호
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• pp.261-267
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• 2015

Compared to their terrestrial and marine counterparts, little is known about the capacity of freshwater-derived actinomycete bacteria to produce novel secondary metabolites. In the current study, we highlight the disparities that exist between cultivation-independent and -dependent analyses of actinomycete communities from four locations in Lake Michigan sediment. Furthermore, through phylogenetic analysis of strains isolated from these locations, we identified a Streptomyces sp., strain B025, as being distinct from other Streptomyces spp. isolated from sediment. Upon fermentation this strain produced a rare class of eight-membered lactone secondary metabolites, which have been for their antitumor properties. We used spectroscopic and chemical derivitization techniques to characterize octalactin B (1) in addition to its corresponding novel, unnatural degradation product (2).

• 한국토양비료학회지
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• 제27권2호
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• pp.111-116
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• 1994

댐 저위층에 축전된 저니와 수강조류를 규조토드럼에 흡착시킨 물질에 대한 농업적 활용 가능성을 검토하기 위하여 Windrow method를 이용한 저니의 부숙퇴비화를 시도하였으며, 저니자체 및 저니함유 부숙퇴비에 대하여 토마토를 공시하여 식물영양적 효과를 포트실험으로 조사한 결과는 다음과 같다. 1. 생계분과 톱밥을 부재료로 한 저니의 부숙방법은 Windrow method를 이용하였다. 부숙과정중 50일 경과후 최종 대(對) 초기 탄질율의 비율은 0.69 수준으로 감소하였고, 양이온치환용량은 약 66%가 증가하였으며, 온도변화는 15일째 $52^{\circ}C$까지 상승하였다가 50일 경과후 $30^{\circ}C$를 유지하여 이 지점을 부숙완료점으로 판정하였다. 2. 미부숙 저니의 토마토에 대한 건물중, 초장 및 엽록소함량에 미치는 효과를 검토한 결과, 대조구에 비해 미부숙 저니 시용구의 효과가 현저하였으며, 시용 수준의 증가와 더불어 건물중 및 초장이 증가하는 경향이었다. 저니 부숙퇴비의 시용 역시, 대조구에 비하여 생체중, 건물중 및 초장의 현저한 증가효과를 나타내었으며, 미부숙 저니에 비해 저니부숙퇴비의 생육효과가 우수하였다. 3. 미부숙 저니 및 저니부숙퇴비를 시용하여 작물재배 후 토양의 물리화학성질을 조사한 결과, pH, T-N, O.M. 및 CEC 면에서 다소 개선효과가 나타났다. 그러므로 저니 및 조류를 직접 토양에 이용하기는 곤란하나 퇴비제조시 충진제로 사용했을 때 부숙화된 저니 퇴비는 토양개량제 및 퇴비자원으로 활용할 수 있는 가능성이 있다고 판단된다.

• Nuclear Engineering and Technology
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• 제52권2호
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• pp.366-372
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• 2020

Using several accessible published data sets, we analyzed the temporal change of ¹³⁷Cs radioactivity (per unit mass of sample) in marine sediments and investigated the effect of the water content of sediment on the ¹³⁷Cs radioactivity, to understand the behavior of ¹³⁷Cs present in marine environments. The ¹³⁷Cs radioactivity in sediments decreased more slowly in the Baltic Sea (near the Chernobyl nuclear power plant) than in the ocean near the Fukushima Daiichi nuclear power plant (FDNPP). The ¹³⁷Cs radioactivity in the sediment near the FDNPP tended to increase as the water content increased, and the water content decreased at certain sampling sites near the FDNPP for several years. Additionally, the decrease in the water content contributed to 51.2% of the average ¹³⁷Cs radioactivity decrease rate for the same period. Thus, it may be necessary to monitor both the ¹³⁷Cs radioactivity and the water content for marine sediments to track the ¹³⁷Cs that was discharged from the sites of Chernobyl and Fukushima nuclear power plants where severe accidents occurred.

• 한국임상수의학회지
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• 제38권2호
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• pp.63-68
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• 2021

Urethral obstruction is a life-threatening feline lower urinary tract disease (FLUTD). The rate of recurring urethral obstruction was 14.8-58.1% after the first occurrence. Ultrasonographic findings associated with reobstruction had been rarely reported although ultrasonography was a valuable technique for diagnosing urinary bladder calculi and distinguishing different FLUTD causes. This retrospective study aims to describe the ultrasonographic findings, urinalysis, and serum chemistry profile in cats with FLUTD and determine the associations of reobstruction with ultrasonographic findings, urinalysis, and serum chemistry profile. The present study included 141 cats that were followed up for more than 1 year. The ultrasonographic criteria included the presence of cystolithiasis, urine echogenicity, sediment, suspended linear strand, pericystic effusion, hyperechoic pericystic fat, ureteral dilation, pyelectasia, and perirenal effusion. The urinalysis criteria included hematuria, urine-specific gravity, pH, sediment, and proteinuria. The most common ultrasonographic findings in cats with FLUTD were echogenic urine and sediment. However, this study did not find an association between reobstruction and ultrasonographic findings, urinalysis, and serum chemistry profiles. Thus, an ultrasonographic examination may be insufficient to predict the risk of reobstruction although it is a useful modality for diagnosing FLUTD and making treatment direction.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 1996년도 가을 학술발표회 초록집
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• pp.53-53
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• 1996