• Applied Biological Chemistry
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• v.23 no.1
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• pp.58-63
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• 1980

Present investigation is undertaken to evaluate residues of organochlorine pesticides and PCBs in river sediments and cultivated soils by GLC. Main sampling areas chosen were three industrial estates, Suwon, Iri and Kumi. Samples consist of river sediments and cultivated soils, in Suwon, Iri and Chilgok, which are likely to be accumulated with PCBs from nearby factories. Organochlorine pesticide residues were found in all sediments and soil samples while no PCBs residue was detected in all samples analyzed. The pesticide residues were greatest in the Suwon and least in Chilgok soils. p,p'-DDT and BHC isomers $({\alpha}-,\;and\;{\gamma}-)$ were found in all soil samples. p,p'-DDT, at the range of 0.006-0.840 ppm, was the most abundant residues among organochlorine insecticides.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.82-90
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• 2004

This study was conducted to evaluate in situ soil flushing and coagulation for naphtalenes-contaminated soil remediation. Mixed-surfactant of 1% POE12 and 1% SDS (1 : 1 by volume basis) was used as a flushing solution. When 5 pore volumes of mixed -surfactant were added to soil column, the flushing efficiencies of 2-methylnaphtalene and 1,5-dimethylnaphtalene with about 1,500 mg/kg(dry soil) were approximately 80% and 60% respectively. In adding 13 pore volumes of mixed-surfactant, the flushing efficiencies of 2-methylnaphtalene and 1,5-dimethylnaphtalene were 90% and 82%. However, considering in situ soil flushing with distilled water, about 42% and 71% were flushed for 2-methylnaphtalene and 1,5-dimethylnaphtalene by surfactant-only. For about 10,000 mg/kg(dry soil) diesel-contaminated soil, 40% and 70% of TPH were flushed-out in 5 pore volumes and 13 pore volumes addition. However, for naphtalenes in diesel TPH, 90% of flushing efficiency was discovered in adding only 5 pore volumes of flushing solution. There was not discovered significant difference among coagulation efficiencies of 6 kinds of polymers, and the coagulation efficiencies were near 50%.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.387-393
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• 2011

We analyzed the particle size distributions of three commercially available Devarda's alloy (DA) products, tested the nitrate recoveries of each particle size category, and examined the amounts of DA required for 100% recovery by varying $NO_3$-N concentration from 0.5 to 10 mg. We observed that use of DA coarser than 200 mesh resulted in poor analytical recovery (<80%). While the tested alloys were considered to be fine enough (>90% of the particles were less than 100 mesh), the recovery dramatically declined from 80% to 10% in a high concentration range (4 to 10 mg N). Satisfactory recovery was obtained by increasing the amount of finer DA (less than 300 or 450 mesh). However, there was no quantitative relationship between the amount of fine DA and nitrate recovered. Generally, the amount of nitrate reduced per unit DA decreased as the recovery efficiency declined. These results suggest that a sufficient amount of DA must be determined based on particle size distribution, and that treatment of at least two levels of DA and comparison of the subsequent change in nitrate recovery is required for soils containing high levels of nitrate. In addition, further studies are encouraged to account for the observed stoichiometric dis-equivalence of recovered nitrate N per unit mass of DA.

• Journal of the Korean earth science society
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• v.22 no.6
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• pp.480-490
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• 2001

The soil-air exchange processes of Hg were investigated from the Hari area of Kang Hwa Island during the late March 2001. In the course of our study, we determined the concentration gradients of Hg and combined these gradient data with micrometeorological components to derive its fluxes. Results of our study indicate that the concentration levels of Hg in the study area are notably lower than those typically found in urbanized areas of Korea. However, the computed fluxes were seen to be significantly larger for relatively remote areas, reaching over 200 ng/m$^2$/hr. Comparison of environmental conditions shows that the concentrations of most pollutant species including NO$_X$ and PM were significantly higher during emission, while meteorological conditions were characterized by high temperature and low humidity. Results of correlation analysis also indicate that such pollutants as hydrocarbons, nitrogen oxides, and PM generally exhibit strong positive correlations with Hg-related parameters during emission events, while such relationships were reversed during dry deposition events. The results of our present study suggest the possibility that the concentrations and fluxes of total gaseous Hg observed during deposition events can be influenced by the processes that are also important for the fine, rather than coarse, size fraction of particles.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.145-159
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• 2020

Wetlands are vulnerable to biological invasion by alien species, because they function as sinks that accumulate excess water, sediments, nutrients, and other contaminants from the surrounding watersheds by disturbance. In this study, to understand the status and characteristics of the alien plants based on the type of wetlands, we classified 24 ecologically outstanding wetlands and analyzed the status of alien flora. A total of 130 alien plants were found in the wetlands, accounting for 11% of the total plant species. Among them, the Asteraceae species was the most diverse, with 40 species. Erigeron annuus and Oenothera ordorata had the highest frequency of occurrence. The species richness of alien plants in the riverine and lacustrine wetlands (average: 30 species) was higher than that in the mountainous palustrine wetlands (average: 10 species). The same results were found in the naturalization index, urbanization index, and ratio of annuals and biennials, which indicate the degree of artificial interference. In the cluster analysis, the riverine and lacustrine wetlands were combined, and only the mountainous palustrine wetlands were separated. The number of alien plants is remarkably low in the mountainous palustrine wetlands, and it is considered to be the influence of Erigeron strigosus, Symphytum officinale, and Bilderdykia convolvulus, not found in the other types of wetlands. In particular, invasive alien plants such as Aster pilosus, Ambrosia trifida, Sicyos angulatus, Ambrosia artemisiifolia var. elatior were found intensively in the riverine wetlands. Therefore, it is considered that a methodical management is urgently required considering the dispersal of alien plants in the riverine and lacustrine wetlands with high artificial interference.

• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.629-641
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• 2006

The Standing Buddha Statue in the Gwanchoksa temple consists of medium to coarse grained biotite granodiorite with dark grey color, and it has a week gneissosity along the pegmatite veins. The results of magnetic susceptibility and geochemical patterns of the host rock of Standing Buddha Statue and the basement rock suggest that both values are formed from the co-genetic magma with the same differentiation process. The CIAs of the basement rock and the Standing Buddha Statue are calculated to 51.43 and 50.86, and the WPIs are estimated 4.52 and 8.95, respectively. So the weathering potential from the host rock of Standing Buddha Statue and basement rock prove to be high. The Standing Buddha Statue is terribly damaged with physical weathering from deterioration and exfoliation, and are scattered with secondary pollutant and precipitate. Basement rock is also in danger of ground collapse because of irregularly developed discontinuity system. Most surface of Standing Buddha Statue is seriously discolored into yellowish brown and dark gray, or black precipitates are also formed. Moreover, it is heavily covered with crustose lichen, fungi and algae, or moss are also found. In order to control the influential factors with the complex deterioration of Standing Buddha Statue, it is needed to rearrange a site environments, and conservation scientific management is required to protect it from covering lichens, exfoliations and fractures.

• The Korean Journal of Malacology
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• v.32 no.1
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• pp.45-54
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• 2016

To evaluate the applicability of cellular energy allocation (CEA) in the bivalves as a biomarker for the assessment of environmental contamination, the energy contents and energy consumption in several tissues of the Manila clam, Ruditapes philippinarum were analyzed. The contents of lipid, glucose, protein and electron transport system (ETS) activity in the foot, siphons, gills, and body of R. philippinarum exposed to crude oil-spiked sediments were measured at 1, 2, 4, 7, 10 days after exposure. The reserved energy (energy available, EA) in the lipid, glucose and protein decreased as contamination level and exposure time increased. In contrast, the ETS activity (energy consumed, EC) showed the reverse tendency. The order of available energy contents were foot > siphons > gill > body. Significant differences in both EA and EC were found only at the highest contamination level (58.3 mg TPAHs/kg DW). EA decreased significantly in the foot and gill at 1 day, in the body at 2 and 7 days after exposure. EC increased significantly in the body at 4 days after exposure. CEA showed higher sensitivity to the contamination than EA or EC. Especially, CEA in the foot and body decreased significantly at lower ranges of contamination level (as low as 6.5 mg TPAHs/kg DW) during 1 to 7 days after exposure. The CEA is more useful than EA or EC alone for the assessment of sediment contamination at lower level that acute toxicity could not be detected. CEA analyses in the body of R. philippinarum after 4 days' exposure to contaminated sediments seem to be the most sensitive and reliable.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.132-132
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• 2000

환경오염과 이상기후의 영향으로 인한 수자원의 고갈과 함께 국내의 경우 수자원 개발 계획 및 수요량을 감안할 때 향후 7 년 내에 물부족 현상을 겪을 것이라는 보고가 있 었으며, 환경부담을 줄이기 위해 폐수의 배출기준은 강화되고 있다. 이러한 상황에서 제조 특성상 타 업종에 비해 폐수 발생량이 높은 편인 국내의 제지산업은 여러 해전부터 이에 대 한 방안을 모색하여 왔다. 일반적으로 폐수 수질 관리와 청수 사용량의 절감을 위해 고가의 폐수 처리 장치를 설치하거나 폐수 재활용을 통해 공정을 극도로 폐쇄화하는 방안으로 연구 가 진행되어 왔다. 이 중 용수의 재활용이 가장 경제적인 방법이지만, 재활용이 지속될수록 각종 무기염과 콜로이드성 유기물질이 축적되어 각종 약품의 효능 저하, 탈수속도의 저하 및 생산 제품의 품질 악화 등의 문제를 유발한다고 알려져 있다. 이를 해결하고자 하는 노 력으로 펄프 원료에 따른 공정수 내 용해성 물질의 분석과 재활용 횟수에 따른 각종 SS와 D DS의 축적 정도에 대한 기초 연구가 수행되었으며, 고폐쇄화된 공정에서 성능을 발휘할 수 있는 첨가제의 개발과 적용 방법에 대한 연구도 수행된 바 있다.여러 지종 가운데 골판지 원지는 용수의 재활용률이 상당히 높은 지종이기 때문에 공정수의 재활용이 진행될수록 열악한 저급 원료로부터 각종의 다양한 물질이 용출 혹은 배 출되며, 이러한‘물질은 골판지 원지의 강도 발현에 더욱 악영향을 미칠 것으로 판단되었다. 미세분으로 구성된 SS의 경우 이미 많은 연구를 통해 특성이 파악되었기 때문에 본 연구에 서는 ss를 제외한 공정수를 두 가지로 크게 나누어 고려하였다. 즉, ss로 측정되지 않지만 닥도를 유발할 수 있는 미세 무기물질과, 용해성의 무기염, 첨가제 및 추출물 둥으로 이루어 진 용해성 성분으로 나누어 분석하였으며, 또한 각각이 초지 특성에 미치는 영향을 살펴보 고자 하였다.을 해석코자 하였으며, 그 방법으 로 수치해석기법을 도입하였다. 또 실제 캘린더링 전후의 두께 변화를 측정하여 유리전이온도 의 도달 깊이와 비교하였다. 지필의 압축 정도는 롤의 직경과 닙 폭을 이용하여 MD 방향으 로 함수화하였으며, 열전달 계수로는 겉보기 값을 사용하였다. 이때 지펼은 균질한 것으로 가 정하였다. 함수율은 유리전이온도를 좌우하는 가장 큰 인자이나 본 연구에서는 항온항습처리 를 통해 유입지의 함수율을 고정시켰으며 캘린더링 시 함수율의 변이는 없다고 가정하였다. 그 결과 열침투깊이가 증가할수록 지필은 보다 변형되기 쉬운 상태가 되어 주어진 압력 조건에 대해 소성변형 정도가 증가하는 것으로 나타났다. 이는 캘린더링 전후에 두께 변화를 측정하여 정량적으로 평가할 수 있었다. 수치해석기법을 통해 같은 압력 조건에서 온도가 증 가함에 따라 혹은 같은 온도 조건에서 압력이 증가함에 따라 지필 내의 유리전이온도의 침투 깊이가 증가함을 알 수 있었으며 이는 캘린더링 전후의 두께 변화의 측정 결과와 일치하였 다. 또 NRT가 증가함에 따라서도 유리전이온도 침투 깊이가 증가하였다.합편에 비해 일부 우수한 양상을 보였지만 본 실험의 범위내에서는 통계적 정량적 차이를 제시할 수는 없었다. 향후 보다 광범위한 동물 실험이 필요할 것으로 사료된다.된다.하고도 완전교정술 도달 확률이 높은 치료전략이라는 사실을 입증하였으며 주대동맥폐동맥혈관부행지의 크기나 숫자가 단일화하기 쉬운 형태학적 특징을 지닌 경우에는 조기에 일단계완전교정술을 시행하여 양호한 결과를 얻을 수 있다는 사실을 발견하였다. 반면 본 환아군 중 단일화술을 먼저 시도한 군에서는 비록 단계적인 단일화를 시도한 군에서 단일화술과 관계된 수술사망율이 약간 낮기는 하였으나 완전교정술까지 완료될 가능성에는 차이가 없었다. 그러나 이 경우 보다 정련된 적응 환자의 선택을 통한 단일화 우선전략의 시도와 장기 추

• Korean Journal of Poultry Science
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• v.45 no.1
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• pp.63-71
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• 2018

This study was conducted to evaluate the effect of age of laying hens on egg internal and external qualities. A total of 8,300 eggs were randomly collected from 15 grading & packaging (GP) centers, and 50 eggs per farm during April to May in 2015. Age of laying hens ranged from 18 to 65 weeks of age and they were classified into 5 age groups (18~25, 26~35, 36~45, 46~55, and 56~65 weeks). Egg weight increased, but the Haugh unit decreased as the age of laying hens increased. Yolk color was higher in eggs laid from 25~35 weeks of laying hens compared with that of 18~25-weeks-old chickens. The incidence of dirty eggs was highest (P<0.05) in 18~25 week group and remained constant after 26 weeks. Among eggshell defects, speckled and pimpled eggs increased as the age of laying hens increased. The incidence of calcium deposits and misshapen eggs was highest during 18~25 weeks of age and remained constant after 26 weeks. The percentage of total eggshell cracks increased as the age of laying hens increased. Among eggshell cracks, star- and hair-like cracks were frequently noted. The percentage of meat spot was higher than that of blood spot and their incidence was highest among the 56~65 week group. Age of laying hens significantly increased egg weight, incidence of pimpled or speckled eggs, star- or hair-like cracks, and meat spot. On the other hand, a significant negative interaction between age of laying hens and the Haugh unit was noted. In conclusion, our study revealed that the age of laying hens affected internal and external egg qualities.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.229-236
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• 2022

This study was conducted to evaluate the efficacy of adding the microbial inoculants to silage for reducing mycotoxins in rice straw silage. When a single agent of L. plantarum and a mixed agent of L. plantarum and S. cerevisiae were added in rice straw silage contaminated mycotoxins, it had an effect on silage fermentation and fiber degradation as well as mycotoxin reduction. Among the mycotoxins, only ochratoxin A and zearalenone were found in the test sample. Ochratoxin A and zearalenone showed a decreasing trend with the addition of silage inoculants compared to the control groups (38.11±2.22 and 633.67±50.30 ㎍/kg), and there was a significant difference at the mixed agents; 27.78±2.28 and 392.72±25.04 ㎍/kg, respectively (p<0.05). The pH was lower in the single agent and the mixed agent compared to the control (p<0.05). The concentration of lactic acid was higher in the single agent (11.73±0.31 mM) than in the control group (8.18±0.93 mM), and the highest concentration was 16.01±0.88 mM in the mixed agent (p<0.05). Acetic acid and propionic acid were found to be significantly lowered with the addition of silage inoculants (p<0.05). Total VFA was also lower at the addition of silage inoculants than the control group (p<0.05). The rumen in situ dry matter degradation of NDF and ADF was maintained at the highest levels of the mixed agent during the culture period, followed by the single agent and the control group at the lowest level. NDF and ADF degradation showed a significant difference at all time points after 12 and 24 hours of culture, respectively (p<0.05). The study results showed that the silage inoculants had the positive effects on quality increasing of rice straw silage; fermentative charateristics, fiber degradation and mycotoxins reduction. Ochratoxin A and zearalenone were greater reduction by adding bacterial inoculants of silage. Therefore it is considered that L. plantarum and S. cerevisiae will improve the quality and stability with remediation of mycotoxin in silage.