• 한국환경복원기술학회지
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• 제13권5호
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• pp.1-11
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• 2010

It is very difficult to control the expansion of reed at a wetland ecological park due to their aggressive reproduction capability. Therefore, proper topography and wetland hydrology should be provided before the construction of a wetland ecological park. Appropriate measures should be taken at the initial stages to prevent reed expansion. Field experiments were conducted at the newly constructed wetland ecological park for 15 months to develop methods to control the reproduction and expansion of Phragmites communis. A complete shading method had the best effect on the prevention of reed reoccurrence among other methods. Complete removal of the rhizomes controlled the reed growth to a greater extent than cutting the aboveground shoots. Water-level manipulation was also better than a half-shading method for the prevention of reed reproduction. These results indicated that soil properties and edge effects can influence the reed growth. Cutting only the aboveground shoots facilitates the growth of reed. These results suggest that reed control should be implemented repeatedly and an alteration in the wetland topography and hydrology may be more effective in the long term. Combination of treatments such as water-level management with shading should be considered to control the growth of reed. Adoptive management for created or restored ecosystem might be considered for accomplishment of its original purpose.

• Journal of Nutrition and Health
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• 제41권1호
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• pp.5-12
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• 2008

In order to investigate whether Eisenia bicyclis (EB) as a functional food material improves serum lipid status, supplementation of EB powder or EB extract to the high fat/cholesterol diet was tested in 6-week old male Sprague-Dawley rats for four weeks. In the first experiment, four kinds of seaweed powder -Eisenia bicyclis (EB), Undaria pinnatifida (Up), Laminaria japonica (LJ), and Ecklonia stolonifera (ES) were compared with alginic acid (ALG) as well as control. In the second experiment, EB water extract and EB ethanol extract and EB pill containing EB and LJ powder were compared with the EB powder. Amounts of dietary fiber contained in experimental diets were adjusted to provide 5% of diets. Serum total cholesterol was significantly lower only in rats fed LJ or EB powder, but HDL cholesterol was higher in rats fed UP, LJ, ES or EB powder. Ratios of HDL-/total cholesterol of all seaweed groups including ALG were significantly higher than that of the control group. Serum triglyceride was lower in LJ, EB nd ES powder groups than the control group. In comparison of EB extracts, triglyceride level was decreased in rats fed only EB water extract as compared to control rats, but HDL cholesterol was elevated with both water and ethanol extracts. Serum levels of total cholesterol, triglyceride were decreased and HDL cholesterol was increased by the EB pill. Serum levels of thiobarbituric acid-reactive substances were lower in rats fed ES powder, and EB powder, EB water extract or EB pill, as compared to the control rats. Supplementation of EB powder and EB pill reduced serum level of GOT and GPT, respectively, as compared to the control group. In conclusion, EB and EB pill improve serum lipid status and may be utilized as ingredient of functional foods for the purpose of improving serum lipid profile and inhibiting peroxidation of lipids.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 추계학술발표회요약집
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• pp.84-84
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• 2001

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 춘계학술발표회요약집
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• pp.57-57
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• 1999

• 한국습지학회지
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• 제14권2호
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• pp.289-301
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• 2012

조석의 영향에 의해 해수의 유 출입이 용이한 해수호수를 친수 친환경으로 조성하는 계획이 인천 송도에서 수행되었다. 본 연구는 조석의 영향을 받는 해수호수의 수리동역학적 거동을 분석하기 위해서 1차원 수치모형인 CEA모형과 2차원 수치모형인 FLOW2DH를 이용하여 수로의 폭에 따라서 변화하는 해수호수 내의 수위 및 유속을 계산하였다. 연구 결과, CEA모형을 이용하여 수로의 적정 폭은 100.0m로 선정되었고, 외해 조위와 인공호수 수위의 지체시간과 수로 내 최대 유속이 계산하였다. 이 결과를 FLOW2DH와 연동하여 해수호수 내의 수위 및 유속을 각각 선정된 관측점에 대하여 비교 분석하였다. 또한, 인공호수의 유지관리 측면에서 수문이 설치된 경우에 대하여 수치모형 실험을 추가하여 수문이 설치되지 않은 경우보다 유속이 창조 시 약 20%, 낙조 시 약 50% 감소하는 효과를 얻었다.

• 환경영향평가
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• 제21권1호
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• pp.81-91
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• 2012

In this study, it is grasped the status of nutrients through an investigation of release characteristics and physicochemical properties of sediments on reservoir. And then the effect of sediments is evaluated on the water quality in reservoir. In the results of physicochemical analysis, the pollution level of midstream is the highest, which shows the traits that the water is more deeper and takes place a deposition consistently. Then, the pollution level of upstream is higher than downstream's because inflow has influence on the upstream directly. The downstream is located near tidal gate so that the soil particles can be moved easily and are difficult to be deposited due to the distribution of seawater by control of tidal gate. Therefore, the downstream is showed the lowest pollution level than the others. Also, the concentration of SOD(Sediment Oxygen Demand) in the upstream which is influenced on the effect of inflow is highest than the others. When it analyzes under anaerobic and aerobic condition to understand the release characteristic of sediment, it shows that the release rate is low or negative under the aerobic condition. Whereas the release rate is usually positive under the unaerobic condition relatively. According to these results, it is necessary to maintain the proper environmental factors of water body for decreasing the release rate of sediment. Because the release rate is changeable under the different condition of water body. Therefore, proper strategies are required for increasing the self-purification of water as well as keeping the aerobic condition of sediment and managing a sediment layer directly to control the inner-pollution by the sediment of reservoir.

• 한국지역사회생활과학회지
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• 제15권1호
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• pp.105-113
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• 2004

This study investigated the synergy effects of hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine on the lipid metabolism and antioxidant defense system of rats on hypercholesterol diets. Sprague-Dawley male rats were fed either a hypercholesterol diet with water or a hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine. The experimental groups consisted of the control group (CO), the group supplied with hot water soluble extract from Eleutherococcus senticosus(ES), and the group supplied with hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine(ESC). Eleutherococcus senticosus was extracted, made into 0.5% solution, and fed to the ES and ESC groups. A 3% carnitine diet was supplied to the ESC group. Hypercholesterol diets contained 18% beef tallow and 5% cholesterol. After 4 weeks of administering these diets, serum and liver were obtained and the level of serum lipid and the activities of GOT and GPT were measured. In addition, the level of liver lipid and TBARS and the activity of GSH-Px were measured. The results were as follows: 1) Weight gain and FER in the group supplied with hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine(ESC) was low significantly(P<0.05). 2) In the groups supplied with hot water soluble extract from Eleutherococcus senticosus(ES) and the group supplied with hot water soluble extract from Eleutherocorcus senticosus and dietarty carnitine(ESC), total serum cholesterol levels were both significantly low (P<0.05,P.0.01). 3) Serum GOT activity was significantly low(P<0.05) in the group supplied with hot water soluble extract from Eleutherococcus senticosus(ES) and in the group supplied with hot water soluble extract from Eleutherococcus senticosus and dietary carnitine(ESC). There was no difference between serum GPT activity in the control group and the groups supplied with hot water soluble extract from Eleutherococcus senticosus or dietary carnitine. 4) Liver triglyceride was low (P.0.05) in the group supplied with hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine(ESC). No difference was observed in other lipid composition, TBARS level, and GSH-px activity in liver between the control group and the experimental groups. In summary, the effects of hot water soluble extract from Eleutherococcus senticosus and dietarty carnitine on the lipid metabolism and antioxidant defense system (such as weight gain, FER, total serum cholesterol and liver triglyceride) were low when Eleutherococcus senticosus and dietarty carnitine were supplied simultaneously.

• 대한토목학회논문집
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• 제43권5호
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• pp.601-610
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• 2023

하천의 수위변화 특성에 대한 이해는 여러 수방활동 및 하천환경의 관리를 위하여 필수적이다. 본 연구는 각종 수방활동에서 종사하는 현장 엔지니어가 특정 지점의 홍수시 수위상승 특성을 간편하게 확인하고 활용할 수 있는 방법론을 제시하는 데 목적이 있다. 이를 위하여 한강수계의 홍수취약지구에 홍수정보를 제공하고 있는 45개 관측소의 2010년부터 2022년까지의 10분 단위 수위자료를 이용하여 홍수 사상에서 발생하는 시간적인 상승량을 단위시간을 통하여 정량화하고 분위화한 수위상승거동곡선(WRBC) 개념을 제시하였으며, 그 적용성을 검토하였다. 분석결과, 홍수시의 수위상승 거동은 평균적으로 초반 6.2시간 이내에 전체 수위상승량의 80% 이상이 상승하며 그 이후에는 점진적으로 상승하는 것으로 분석되었으며, 수위상승 이후에 일정한 평형상태에 도달하는 시간은 상류유역의 면적과 유출 특성에 따라 다른 것으로 나타났다. 이러한 WRBC는 홍수유출로 인하여 발생하는 수위상승의 평균적인 경향에 대해 통계적이고 직관적인 검토에 장점이 있으며, 하천변에 위치한 친수공간, 수리시설 등의 수방활동에 활용할 수 있을 것으로 기대된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2064-2069
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• 2008

The Resonance Control Cooling System (RCCS) prototype installed in KAERI site has been designed to control the resonant frequency of the normal conducting drift tube linac (DTL) for the Proton Engineering Frontier Project (PEFP). The RCCS water pumping skid is composed of two channels as a by-passing the cooling water and a plate heat exchanger. The required temperature can be achieved by mixing both channels in order to control its the resonant frequency at 350 MHz. The temperature controlled water pumping skid operates in combination with the Low Level Radio Frequency (LLRF) system. We have discussed the design, modeling with each components, control scheme, fabrication and test results of the water pumping skid for resonant frequency control of the DTL cavity. In conclusion, the fabricated RCCS prototype through the optimization of modeling has corresponded with the design requirement and concept.

• 한국강구조학회 논문집
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• 제25권6호
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• pp.613-622
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• 2013

우리나라의 지형 특성상 많은 중소하천들이 생성되어 있으며, 이에 대한 치수 목적으로 다양한 보가 건설되고 있다. 그 중 가동보는 고정보에 비해 저수위를 자유롭게 조절할 수 있고, 상류부 저층수의 수질악화, 수변 생물 서식처의 변화 등 고정보의 문제점을 개선할 수 있기 때문에 그 적용빈도가 증가하고 있는 추세이다. 이 연구에서는 가동보의 종류 중 하나인 다단전도방식 가동보에 대한 특징을 조사하고, 시공된 구조물을 예로 구조적 성능을 확인하기 위한 해석적 연구를 수행하였다. 또한, 유한요소해석을 통해 얻은 결과로부터 다단전도방식 가동보의 우수한 구조적 성능을 확인할 수 있었다.