• Journal of Chest Surgery
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• 제27권1호
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• pp.31-35
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• 1994

Dissecting aortic aneurysm is a life threatening condition which necessitates prompt diagnosis and management. Between January 1987 and September 1993,58 patients was admitted to our department. Mean age at admission was 53 years.[range 25-82]. Clinical findings included chest pain in 48 cases[83%],renal failure in 12[20%],aortic insufficiency in 11[19%] and stroke in 9[15%]. Predisposing factors were hypertension in 50 cases[86%],Marfan`s syndrome in 6[10%] and diabetes melitus in 1 [2%]. 23 patients[ type A 13,type B 10 ] underwent surgical treatment. Surgical technique for type A included graft replacement of ascending aorta in 7 cases,graft replacement and aortic valve resuspension in 3,and Bentall`s operation in 3 cases. Type B patients were operated when specific indications applied. There were three [Two in type A and 1 in type B] deaths in the operation group and nine [ 5 in type A and 4 in type B] deaths in the medical group. These results support our current policy in the treatment of dissecting aortic aneurysm.

• Nuclear Engineering and Technology
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• 제46권6호
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• pp.825-836
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• 2014

Predicting radioactive fission product (FP) behaviors in the reactor coolant system and the containment of a nuclear power plant (NPP) is one of the major concerns in the field of reactor safety, since the amount of radioactive FP released into the environment during the postulated accident sequences is one of the major regulatory issues. Radioactive FPs circulating in the primary coolant loop and released into the containment are basically in the form of gas or aerosol. In this study, a multi-component and multi-sectional analysis module for aerosol fission products has been developed based on the MAEROS model [1,2], and the aerosol transport model has been developed and verified against an analytic solution. The deposition of aerosol FPs to the surrounding structural surfaces is modeled with recent research achievements. The developed aerosol analysis model has been successfully validated against the STORM SR-11 experimental data [3], which is International Standard Problem No. 40. Future studies include the development of the resuspension, growth, and chemical reaction models of aerosol fission products.

• 한국수산과학회지
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• 제31권3호
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• pp.323-329
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• 1998

황해 남동해역 투명도의 계절변화를 보기 위하여, 25개년 ($1966\~1990$)간의 해양조사 연보를 이용하여 우리나라 서해의 격월별, 정점별 자료를 정리하였다. 투명도의 분포는 계절에 관계없이 등수심선과 유사하게 뚜렷한 동서 대비를 보이고 있었다. 수심이 얕은 연안역에서는 3m(2월)$\~$8m (8월)로 낮고, 수심이 깊은 외양역에서는 10m (2월)$\~$17m (8월)로 높다. 겨울철 ($12\~2$월)은 투명도가 $\4m~10m$의 범위로, 여름철 ($6\~8$월)의 $6m\~17m$ 보다 낮다. 또한 부유 물질의 농도를 보면, 2월에는 $20\~120mg/\ell$이고 8월에는 $8\~20mg/\ell$의 범위였다. 성층과 투명도와의 관련성을 보면, TR(투명도)=0.61 DT(성층)+6.90, r=0.85로 양의 상관을 보이고, 정선 309에서 겨울의 보퍼트 풍력 계급은 약 3.5 내외로 여름보다도 약 1계급 이상 높은 값을 보였다. 이와 같은 사실들은 황해 남동해역에서의 투명도의 계절 변화는 겨울의 경우, 해수면 냉각과 바람에 의한 상하층 연직 혼합으로 저층 퇴적물의 재부유가 활발하여 투명도가 낮게 나타난다. 그리고 여름에는 해수면 가열에 의해서. 상하층 사이에 형성되는 수온 혹은 밀도 약층과 조석 혼합을 방해하는 태양 복사열의 증가로 인하여 저층 퇴적물의 재부유가 방해되어. 투명도가 높게 됨을 나타내고 있다.

• 한국해양학회지
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• 제22권2호
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• pp.105-118
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• 1987

금강 하구의 에스추어리 환경에서 6차에 걸친 야외조사 및 정선관측이 행해졌 다. 각 조사시기는 모두 다른 조차와 하천배수량의 조건을 보여 주는 기간이었다. 이 연구의 결과로서 금강하구에서의 세립질 퇴적물 퇴적작용에 최대 혼탁수의 형성 과 그 변화가 미치는 영향이 지대함이 나타났다. 금강 에스추어리의 최대혼탁수는 일차적으로 입구에서의 조차가 클 때는 나타나는 현상이며, 바닥 퇴적물의 재부유 에 의해 형성되어 진다. 이 환경에서는 최대 혼탁수가 지속적으로 유지되어 지지 않고, 반일, 반월 및 계절주기의 변화를 나타낸다. 반일 조석주기 동안에는 조류 유 속의 변화로 말미암 아세립질 퇴적물의 퇴적과 재부유가 반복되어 진다. 한편, 최대 혼탁수의 중심은 창조류와 낙조류가 반복되는 것에 상응하여 상-하류 이동을 반복 한다. 채대 혼탁수는 대조기-소조기의 변화에 따른 15주기의 변화를 나타낸다. 이렇 게 하여, 최대 혼탁수는 소조기 동안에 쇠퇴하고 대조기 동안에 확장된다. 하천 배 수량의 계절변화도 또한 최대 혼탁수의 생성과 소멸에 중요한 영향을 미친다. 우기 에 하천배수량이 증가하게 되면 조류가 낙조류 우세를 나타내고, 부유퇴적물들은 쉽게 외해로 유출되어 에스추어리 내에서의 체류시간이 감소되어 진다. 따라서, 이 와 같은 많은 하천배수량의 시기에는, 최대 혼탁수의 발단은 오직 대조기 동안으로 만 국한되어 지며, 조차가 감소함에 따라 최대 혼탁수는 소멸한다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.161-166
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• 2004

Research for deposits in Nakdong eatuary that research about Nakdong eatuary's sediment flows out in Nakdong-kang so far had been progressed but research about deposits that is flowed in open sea is insufficient. Observed Nakdong eatuary's characteristic of sediment transfer through observation during the second during Buteo 20 days on February 6, 2004 in this research Resuspension bed load Flux appeared high the first result St.4 point and St.5 point. St.4 branch had much bed load amount that is flowed in the east, and bed load that St.5 branch is flowed in the south appeared much Tendency such as the first showed in the second result, but compare with the first result and St.5 branch had much bed load that is transfer in end. Bed load that is transfer in observation result Nakdong river was less. As this, can know that amount of sediment that is transfer in open sea more than deposits that is transfer in Nakdong river is much Is expected to exert effect that deposits that is transfer in open sea is high in Nakdong estuary's topography change. Specially, observation result is expected that Nakdong estuary's deposition tendency becomes Jinwoodo southern and Shinho southern.

• 상하수도학회지
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• 제28권3호
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• pp.277-286
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• 2014

Water discolouration and increased turbidity in the local water service distribution network occurred from hydraulic incidents such as drastic changes of flow and pressure at large consumer. Hydraulic incidents impose extra shear stresses on sediment layers in the network, leading to particle resuspension. Therefore, real time measuring instruments were installed for monitoring the variation of water flow, pressure, turbidity and particulates on a hydrant in front of the inlet point of large apartment complex. In this study, it is attempted to establish a more stable water supply plan and to reduce complaints from customers about water quality in a district metering area. To reduce red or black water, the water flow monitoring and control systems are desperately needed in the point of the larger consumers.

• Environmental Engineering Research
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• 제17권3호
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• pp.167-174
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• 2012

In situ particle size spectra are obtained from two sequent cruises in order to evaluate the physical consequences of suspended particulate matters caused by episodic storm runoff from the Santa Ana River watershed, an urbanized coastal watershed. Suspended particles from various sources including surface runoff, near-bed resuspension, and phytoplankton are identified in empirical orthogonal function (EOF) analysis and an entropy-based parameterization (Shannon entropy). The first EOF mode is associated with high turbidity and fine particles as indicated by the elevated beam attenuation near the Santa Ana River and Newport Bay outlets, and the second EOF mode explains the suspended sediment dispersal and particle coarsening at the near-surface plume. Chlorophyll particles are also distinguished by negative magnitudes of the first EOF mode, which is supported by the relationship between fluorescence and beam attenuation. The integrated observation between the first EOF mode and the Shannon entropy index accentuates the characteristics of two different structures and/or sources of sediment particles; the near-surface plumes are originated from runoff water outflow, while the near-bottom particles are resuspended due to increased wave heights or mobilizing bottom turbidity currents. In a coastal pollution context, these methods may offer useful means of characterizing particle-associated pollutants for purposes of source tracking and environmental interpretation.

• 환경생물
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• 제37권3호
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• pp.268-277
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• 2019

Severe damages will result in human society, when several different critical natural phenomena coincide. One example relates to the resting cysts of Alexandrium species (dinoflagellates that cause paralytic shellfish poisoning), which are preserved in surface sediments throughout Osaka Bay, Japan. These cysts have been found to accumulate particularly densely in shallow areas in the inner parts of Osaka Bay, where a tsunami caused by an earthquake could occur any time. Damage by a tsunami could cause a change of the coastal ecosystems at Osaka Bay including the resuspension of surface sediments containing resting Alexandrium tamarense cysts and the subsequent redistribution of the cysts in newly deposited sediment. Under certain environmental conditions, these cysts could germinate and form dense blooms, leading to paralytic shellfish poisoning. Such a scenario could also affect other coastal areas, including the southern coast of the Korean Peninsula.

• 한국산학기술학회논문지
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• 제12권6호
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• pp.2872-2878
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• 2011

2010년 여름철 만리포의 수질은 COD(화학적산소요구량)가 개장전부터 폐장 이후까지 지속적으로 2.0 mg/l 이하로 측정되어 양호한 상태였고 SS(부유물질)의 량이 7월 조사에서 30mg/l를 초과하였으나 해수욕에는 무리가 없었을 것으로 판단된다. 식물플랑크톤은 대발생이나 적조 등의 현상이 나타나지 않았다. 대천의 수질은 8월 조사에서 COD값이 평균 2.0mg/l를 초과하기도 하였으나 전체적으로는 2.0mg/l 이하로 나타나 역시 해수욕장 수질로서는 양호하다. 다만 SS가 전체적으로 다소 높은 값을 보이기는 하나 이는 대천해수욕장의 저질특성에 기인한 머드(뻘)의 영향인 것으로 보이며 해당 해수욕장의 특징으로 설명될 수 있다. 식물플랑크톤 역시 규조류가 우점하는 보편적인 해수의 특징을 보였다.

• Journal of Applied Biological Chemistry
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• 제50권2호
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• pp.41-45
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• 2007

Polaromonas naphthalenivorans CJ2, responsible for naphthalene degradation at a coal tar contaminated site, was isolated on MSB agar media supplied with naphthalene vapor as the sole carbon source at $10^{\circ}C$. The strain is not isolated under the same isolation condition using the same soil sediment at $20^{\circ}C$ although its optimum temperature is about $20^{\circ}C$. In this work we explored the reason why strain CJ2 could not have been isolated on MSB agar with naphthalene vapor at $20^{\circ}C$. Dispersed CJ2 cells in PBS buffer formed colonies on MSB agar with naphthalene vapor at $10^{\circ}C$ with low naphthalene vapor pressure, but not at $20^{\circ}C$ with high naphthalene vapor pressure. However, streaked cells without resuspension grew on MSB agar with naphthalene vapor at $10^{\circ}C,\;20^{\circ}C$, and even $25^{\circ}C$. Investigation of scanning electron microscopy showed that CJ2 cells formed extracellular polysaccharide (EPS) capsules, which were released easily from CJ2 cells by just dispersion. Therefore, it is concluded that strain CJ2 is able to overcome the naphthalene toxicity by forming a capsule-type barrier around the cells although it is susceptible to naphthalene toxicity at high temperature.