• 한국환경보건학회지
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• 제33권5호
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• pp.408-421
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• 2007

The concentration characteristics of atmospheric particle matters (PM) including $PM_{2.5},\;PM_{10}$, and TSP were evaluated through the measurement data of PM_{2.5}$ (fine particulate), PM_{10-2.5}$ (coarse particulate), and PM_{over-10}$ collected using a MCI (multi-nozzle cascade impactor) sampler of a three-stage filter pack in spring of 2006 in Iksan area. During the sampling period of 10-15 March and 24 days from 8 April to 2 May, 32 samples for PM of each size fractions were collected, and then measured for PM mass concentrations and water-soluble inorganic ion species. Average concentrations of $PM_{2.5},\;PM_{10}$, TSP were $57.9{\pm}44.1mg/m^3$, $96.6{\pm}89.1mg/m^3$, and $114.8{\pm}99.7mg/m^3$, respectively. Water-soluble inorganic ion fractions to PM mass were found to be 36.5%, 18.0%, and 11.1% for $PM_{2.5}$, $PM_{10-2.5}$ and $PM_{over-10}$, respectively. By showing the high concentrations of PM samples during Asian dust events, those three fractions of PM were distinguished between the samples of Asian dust event and the samples of no event. However, the increase of PM concentrations observed during Asian dust events showed a different pattern for some Asian dust events. The differences of those three fractions in the size distribution may depend on differences on place of occurrence of Asian dust storm and course of transport from China continent to Iksan area in Korea. However, the extent of PM mass contribution during Asian dust events was generally dominated by the coarse particles rather than the fine fraction of PM. The variations of water-soluble inorganic ion species concentration in those three PM fractions between the samples of Asian dust event and the samples of no event were also discussed in this study.

• 한국작물학회지
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• 제40권4호
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• pp.518-524
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• 1995

국산 녹차의 채엽시기 및 제차법에 따라 회분, 조지방 및 무기성분 등 일반성분의 변화를 분석한 본 연구의 결과는 다음과 같았다. 채엽기의 신엽의 엽면적은 다엽(평균 7.23$cm^2$)이 봉산리 다엽(평균 6.93$cm^2$)보다 컸으며 엽면적의 변화폭은 2번 채엽기와 3번 채엽기 사이에 봉산리, 부춘리 각각 2.74$cm^2$에서 7.98$cm^2$, 3.10$cm^2$에서 8.23$cm^2$로 가장 컸다. 건물량은 봉산리 평균 26.3%, 부춘리 평균 26.6%이었으며 채엽기에 따라 일정한 경향은 증감을 보이지 않았다. 녹차의 일반성분 중 수분 및 회분 함량은 봉산리 평균 5.6, 6.1%, 부춘리 평균 6.2, 5.8%이었다. 총당함량 및 조지방은 봉산리 평균 4.6, 2.8%, 부춘리 평균 2.8, 2.2%이었으며 후기채엽기에 다소 높은 양을 보였다. 총질소량 및 수용성 단백질은 봉산리 평균 5.1, 1.08%, 부춘리 평균 5.7, 1.02%이었으며 총질소량은 후기채엽기에 감소하였다. 가용성 고형분은 봉산리 평균 33.1%, 부춘리 평균 35.2%이었으며 봉산리의 경우 후기채엽기에 감소를 보였다. 무기성분은 봉산리 평균 2.557%, 부춘리 평균 2.338%, 비타민 C, 비타민 E 및 비타민 A 함량은 각각 봉산리 평균 413, 71.8mg%, 32.15IU, 부춘리 평균 311, 52.3mg%, 25.68IU이었으며 채엽기에 따라 비타민 C와 비타민 E는 후기채엽기에 증가를 보였다. 재차시 증차법 및 부초법 처리에 의한 다엽의 일반성분의 변화는 가용성 고형분함량은 증차법 평균 0.111%, 부초법 평균 0.086% 증가하였으며 조지방은 증차법 평균 0.125%, 부초법 평균 0.241% 감소하였고, 총질소는 증차법 평균 0.019%, 부초법 평균 0.036%, 수용성 단백질은 증차법 평균 0.125%, 부초법 평균 0.078% 증가를 보였다.

• Journal of Ecology and Environment
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• 제40권1호
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• pp.5-11
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• 2016

Background: As the decomposition of lignocellulosic compounds is a rate-limiting stage in the nutrient mineralization from organic matters, elucidation of the changes in soil enzyme activity can provide insight into the nutrient dynamics and ecosystem functioning. The current study aimed to assess the effect of thinning intensities on soil conditions. Un-thinned control, 20 % thinning, and 30 % thinning treatments were applied to a Larix kaempferi forest, and total carbon and nitrogen, total carbon to total nitrogen ratio, extractable nutrients (inorganic nitrogen, phosphorus, calcium, magnesium, potassium), and enzyme activities (acid phosphatase, ${\beta}$-glucosidase, ${\beta}$-xylosidase, ${\beta}$-glucosaminidase) were investigated. Results: Total carbon and nitrogen concentrations were significantly increased in the 30 % thinning treatment, whereas both the 20 and 30 % thinning treatments did not change total carbon to total nitrogen ratio. Inorganic nitrogen and extractable calcium and magnesium concentrations were significantly increased in the 20 % thinning treatment; however, no significant changes were found for extractable phosphorus and potassium concentrations either in the 20 or the 30 % thinning treatment. However, the applied thinning intensities had no significant influences on acid phosphatase, ${\beta}$-glucosidase, ${\beta}$-xylosidase, and ${\beta}$-glucosaminidase activities. Conclusions: These results indicated that thinning can elevate soil organic matter quantity and nutrient availability, and different thinning intensities may affect extractable soil nutrients inconsistently. The results also demonstrated that such inconsistent patterns in extractable nutrient concentrations after thinning might not be fully explained by the shifts in the enzyme-mediated nutrient mineralization.

• 유기물자원화
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• 제7권1호
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• pp.31-42
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• 1999

하수슬러지의 농지이용가능성을 조사하기 위하여 하수슬러지를 주원료로 하여 생산된 퇴비를 토양에 처리함으로써 벼 생육시기별 토양의 화학적 특성 변화, 식물체중 무기성분 및 중금속함량 변화, 현미중 중금속함량변화, 작물생육상황, 수량 및 수량구성요소 등을 조사하였다. 토양중 유기물, 질소, 유효인산 및 치환성카리는 퇴비시용 20일 후 퇴비시용량이 증가할수록 증가하였으며, 수확기에는 퇴비시용 20일 후에 비하여 질소, 유효인산은 현저히 감소하였고, 토양중 중금속함량도 퇴비시용량이 증가할수록 증가하였으나 그 증가 폭은 매우 미미하였다. 수확기의 식물체 부위별 질소 및 카리함량은 퇴비시용구가 대조구에 비하여 모든 부위에서 별 차이가 없었으나, 인산함량은 퇴비시용량이 증가할수록 증가하였다. 그리고 식물체 부위별 및 현미중 중금속함량은 처리간 별 차이가 없었다. 벼 수량은 삼요소에 하수슬러지 퇴비를 각각 1,000, 2,000, 4,000 및 6,000kg/10a 시용 하였을 경우 삼요소구에 비하여 각각 약 3, 18, 44 및 54%증가되었으며, 벼의 건물중, 분얼수 및 주당입수는 하수슬러지 퇴비의 시용으로 증가하였다.

• 한국환경과학회지
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• 제6권6호
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• pp.595-604
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• 1997

To investigate characteristics of biogeochemical environment of the Korea Deep Ocean Study(KODOSI area in the northeast Pacific Ocean, we preferentially measured Inorganic nutrients and fluorescent organic matters. Typically. the permanent thermocline was well developed at the depth of 200~1000m In the study area. Nitrate. phosphate and silicate were low In the surface mixed layer and Increased with depth. N/P and N/Si showed 15 and 0.2 respectively In the deeper layer. Two fluorophores, biomacromolecule(protein-like) and geomacromolecule (humid-like) , were observed by three dimensional fluorescence excltatlon/ emission spectra matrix. Biomacromolecule(maximum fluorescence at $Ex_{280m}/Em_{330nm}$) ranged from 41.9 to 147.0 TU with its maximum In the surface mixed layer and minimum in deeper water, This is a same trend that has been reported for DOC in the equatorial Pacific. This suggests that biomacromolecule might be labile and converted to refractory humic substance after bacterial degradation In the deeper layer. On the contrary, geomacromolecule(maximum fluorescence at $Ex_{330m}/Em_{430m}$), ranged from 7.6 to 46.5 QSU, showed minimum in the surface nixed layer(euphotic zone) Implying photodegradation and then increased with depth at all stations. In the characteristics of vertical profiles, the relationship between biomacromolecule and geomacromolecule showed negative correlation. Such trend can be attributed to biochemical regeneration or formation of fluorescent materials accompanying oxidation and rennnerallzation of settling organic matter.

• 한국임상수의학회지
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• 제23권3호
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• pp.375-379
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• 2006

Detection of wooden foreign body represents a clinical challenge. Wood is typically radiolucent, so wooden foreign bodies are generally cannot be seen on survey radiography. Failure to locate and remove foreign bodies can lead the patient to the long-term secondary inflammatory reactions or infections. The dog described in the present report ingested a wooden foreign body(cotton swab stick) a year ago. The foreign body remained in the intestinal tracts which were attached to each other due to the prior abdominal operation. The wooden piece in the intestine functioned as a nidus and inorganic matters were gathered forming calculus on the outer layer of foreign body. In the radiograph, the foreign body appeared to be a chicken bone which of it's inner area was more radiolucent than the outer layer. Because the wooden foreign bodies that have remained for long time in the intestinal tract can be seen like a bone by mineralization, the diagnosis of the wooden foreign bodies should be done prudently.

• 한국환경과학회지
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• 제9권3호
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• pp.267-273
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• 2000

In order to understand the impact for decomposition of blue-green algae Microcystis on water quality, the algae were cultivated with collection of natural population during approximately one month, when water-bloom of Microcystis dominated at August 31, 1999 in the lower part of the Okchon Stream. The enrichment of inorganic NㆍP nutrients didn't in algal assay and the effect of Microcystis on water duality was assessed from the variation of nutrients by algal senescence. Microcystis population seemed to play a temporary role of sink for nutrients in the water body. Initial algal density of Microcystis was 2.3×10/sup 6/ cells/㎖. When Microcystis population died out under light condition, algal NㆍP nutrients between 9∼12 days affected to increase of biomass after reuse by other algal growth as soon as release to the ambient water. However, cellular nutrients under dark condition were almost moved into the water during algal cultivation. NH₄, NO₃ and SRP concentration were highly increased with 160, 17 and 79 folds, respectively relative to the early. As a result, the senescence of Microcystis population seemed to be an important biological factor in which cause more eutrophy and increase of explosive algal development by a lot of nutrients transfer to water body. There are significantly observed an effort of reduce for production of inner organic matters such a phytoplankton as well as load pollutants from watershed in side of the water quality management of reservoir.

• 생태와환경
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• 제42권2호
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• pp.221-231
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• 2009

This study was carried out to comparatively identify characteristics of turbid water influence in Imha Reservoir, Soyang Reservoir, and Daecheong Reservoir in Korea. We used 3 years dataset from 2002 to 2004 and analyzed seasonal water quality characteristics, particular parameters in association with turbidity, and light transparency to figure out the trends. All parameters to be used in the study were total phosphate (TP), total nitrogen (TN), chlorophyll-${\alpha}$ (Chl), suspended solids (SS), Secchi depth (SD), conductivity, and verticallight extinction coefficienct($K_d$), euphotic zone ($Z_{eu}$), and critical depth ($Z_p$). All parameters depend on season and watershed. Suspended solids from Soyang Reservoir were usually caused by TP, mainly related to living wastes and agricultures in upper stream. Daecheong Reservoir was influenced by organic matters related to large phytoplankton biomass in summer and inorganic suspended solids by nutrients in the winter. However, in case of Imha Reservoir, turbid water, consisted in silt and clay through heavy precipitation remained in the waterbody to decrease water transparency along with TP and caused the light limitation in winter. Overall results suggest that it was necessary to establish various management programs because the reasons occurring turbidity were varied according to the reservoir circumstances.

• 한국패류학회지
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• 제29권3호
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• pp.239-244
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• 2013

Mass mortalities of farmed shellfish, mostly in summer season, thus named mass summer mortalities, have been a global issue in shellfish aquaculture. The 2013 mass summer mortalities in the confined waters of Goseong Bay, Goseong, Korea were quite a unique and intensive for two farmed species, the Pacific oysters, Crassostrea gigas, and bay scallops, Argopecten irradians. The mortalities were progressive from the bottom of the suspended oysters and caged scallops in the waters, reaching up to 80% for the oyster and 95% for the scallop in about 20 days after the first occurrence, early August, 2013. We monitored a wide range of environmental factors, including water temperature, dissolved oxygen (DO), salinity, turbidity, acidity (pH), organic and inorganic matters, chemical oxygen demand (COD), suspected pathogenic agent, and phytoplankton composition throughout the water column where the two species were suspended or caged. Our survey concluded that the hypoxia or anoxia might be a major cause of the mortalities. Here, we detailed the mortalities and ways to arrive at the conclusion.

• 생태와환경
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• 제35권1호통권97호
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• pp.1-9
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• 2002

팔당호 지류인 경안천의 입자태 및 무기 영양염의 동태와 이들이 식물플랑크톤의 군집구조의 천이에 미치는 영향을 규명하기 위하여 1993년 8월 18일부터 11월 13일까지 주 1회의 조사를 14주 동안에 걸쳐서 수행하였다. 질산성 질산염은 조사기간 중 항상 풍부하였고 인산염과 규산염은 갈수기에 급격히 감소하는 경향을 보였다. Chlorophyll a의 값은 1993년 8월 21일 $90.6\;{\mu}g/l$로 최대 값이 관찰되었으며 10월 중순 이후부터는 $15{\sim}16\;{\mu}g/l$을 유지하였다. 입자태 유기탄소와 입자태　유기질소는 매우 풍부한데 비해, 입자태 유기인의 농도는 최저$0.3\;{\mu}g\; atm/l$의 낮은 능도 분포를 보였으며, 입자태 유기탄소 및 유기질소의 변화양상은 chlorophyll a의 변차양상과 잘 일치하였으며, 이것은 입자태 유기탄소 및 질소는 식물플랑크톤의 성장에 의한 내생적 공급에 의함을 의미한다. 이와는 반대로 경안천의 인의 공급은 외부로부터 공급되고 있으며, 항상 인산염이 식물플랑크톤의 제한인자로 작용하지만, 때때로 낮은 Si/P ratio을 나타내어 규산염의 고갈 현상이 관찰되었다. 이 결과는 때로는 식물플랑크톤의 성장에 인산염 보다는 규산염이 제한 인자로 작용한다는 것을 암시한다. 인산염이 제한 인자로 작용하는 시기에는 규조류가 우점하고 있었으며, 규산염이 제한인자로 작용하는 시기 (9월 $11{\sim}18$일, 10월 $2{\sim}16$일)에는　남조류와 녹조류가 우점 하였다. 특히,　남조류 중에서 Anabaena, Microcystis및 Oscillatoria가 우점종으로 출현하였다.