• Journal of Aquaculture
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• v.10 no.2
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• pp.105-112
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• 1997

For improvement of fishermen's income by oyster cultivation in eastern coast of Korea, the spats of oyster (Crassostrea gigas) collected from Hadong in southern coast of Korea were transplanted to Chumunjin and cultured by hanging long line method from August 1994 to July 1995 for examination of their growth and ground environmental conditions. The environmental conditions show the annual range of water temperature as 8.33~$25.62^{\circ}C$, salinity as 32.84~$34.28\textperthousand$, PO4-P as 0.09~0.40$\mu$g-at/1, dissolived inorganic nitrogen (DIN) as 0.32~3.21$\mu$g-at/1. The growth of oyster in hanging culture was as follows : 88.7mm (shell hight) in upper layer (7m), 84.9mm in middle layer (10m) and 78.0mm in lower layer (13m) after one-year cultivation. Thus, the oysters in upper layer had grown relatively faster than those in lower layer. The relationships between shell hight (SH) and shell length (SL) in each culturing depth as follows : SL=0.5403 SH+8.5486 (r=0.9959) in upper layer, SL=0.5813 SH+3.7775 (r=0.9869) in middle layer, and SL=0.5159 SH+6.8736 (r=0.9961) in lower layer. The meat weight of oyster was the highest value as 13.24g in upper layer, and 12.68g in middle layer, and lowest as 10.96g in lower layer. The relationships between total wight (TW) and meat weight (MW) with culturing water layer were as follows : MW=0.1933 TW+0.1051 (r=0.0073) in upper layer, MW=0.1915 TW+0.1894 (r=0.9984) in middle layer, and MW=0.1650 TW+0.0558 (r=0.9983) in lower layer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1184-1189
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• 2001

This study was conducted to investigate the effect of Hijikia fusiforme extracts on serum lipid and liver antioxidative enzyme activities in triton-induced hyperlipidemic rats. Sprague-Dawley male rats divided into 7 groups : We injected saline to a normal group (N), saline and tween 80 to control groups (CS, CT) and tot extracts to experimental groups (CSA, CTEtOH, CTE, CTH) for 7 days and then injected triton at the last day. Serum and liver free cholesterol contents were significantly lower in hexane-treated group (CTH) than control group (CT) whereas serum HDL-cholesterol content was higher in aqueous extract group (CSA) than control group (CS). Total cholesterol and phospholipid contents in serum and liver were lower in aqueous extract group (CSA) than control group (CS). Serum and liver triglyceride contents were significantly lower in ethanol (CTEtOH) and hexane treated group (CTH) than control group (CT). Thiobarbituric acid reactive substances of liver were lower in tot extract groups (CSA, CTEtOH, CTE, CTH) than control groups (CS, CT). Superoxide dismutase activities in liver were significantly lower in aqueous extracts group (CSA) and hexane treated group (CTH) than control groups (CS, CT). Liver catalase activity was the lowest in ethylacetate extract group. These results showed that some Hijikia fusiforme extracts have reduction effect of lipid and antioxidative effect in triton-induced hyperlipidemic rats.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.2 s.51
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• pp.153-159
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• 2005

In this study, we investigated the application of an extract from Ephedra sinica which has been composed of traditional Korean medicine as a whitening ingredient. The extract of Ephedra sinica which was obtained from the mixture of methanol and water (1:1) the inhibitory effect of tyrosinase. Then, Ephedra sinica was extracted by two different solvents. One was water and the other was methylene chloride. Only, the water extract of Ephedra sinica showed the inhibitory effort of tyrosinase; the anti-tyrosinase activity with $0.2\%$ of the water extract was $60.6\%$. But the extract of Ephedra sinica in methylene chloride fraction showed little inhibitory effect on tyrosinase. The inhibitory effect of the concentrated water extract of Ephedra sinica was tested on L-DOPA auto-oxidation and melanin synthesis in B-16 melanoma. In L-DOPA auto-oxidation, $0.5\%$ of the concentrated water extract showed $87\%$ of inhibition of L-DOPA auto-oxidation and the $0.75\%$ concentrated Ephedra sinica extract in wafer fraction inhibited $98.8\%$ of that. In melanin synthesis of B-16 melanoma, the concentrated water effect of Ephedra sinica inhibited $70.2\%$ or $79.9\%$ of inhibitory effect on that at the concentration of $0.05\%$ or $0.075\%$, respectively. For verifying the skin whitening effect of the concentrated water extract of Ephedra sinica in vivo, we performed the clinical test of that. The research showed the significant skin whitening effect of a cream containing $0.5\%$ Ephedra sinica extract and the statistical analysis showed a significant difference (p < 0.05) between sample (containing $0.5\%$ Ephedra sinica extract) and placebo after 10 weeks.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.6
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• pp.353-360
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• 2010

The Kyunggi Bay in mid-west of Korea is a relatively large estuarine system that connects the Han River system with Yellow Sea. Due to macro-tidal range of more than 8 m, the urban estuary shows deep tidal channels and wide tidal flats. Since last 30 years, the coastal development is undergoing, yielding noticeable change in environment. Particularly the tidal flat dynamics are generally accepted as being related with tidal residual flows in this area (Kim et al., 2009). We have estimated the annual variation and vertical structure of residual currents with one-year long observed flows in two major tidal channels of Kyunggi Bay. The moving average method and tidal current harmonic analysis yield nearly the same results on residual flow. The residual flow in Jangbong channel ranges from 20 cm/s in summer to 30 cm/s in winter. It is noticeable that the residual flow in Jangbong channel is flood dominant throughout the year, while the flow in Seokmo channel is ebb-dominant residual flow with current speed range of 20-40 cm/s. Due to the baroclinic response of relatively shallow estuary, significant reduction of energy in bottom layers have been observed, indicating the importance of residual circulation to the tidal flat behavior.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.462-462
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• 2018

국내 신규댐 건설에 있어, 침수토양의 용출에 의한 호내 수질영향에 대해서는 현재까지 정량화된 사례는 찾기 어려우며, 댐 담수 초기에 증가되는 오염원에 대한 정확한 조사자료의 부족으로 담수이후의 수질변화에 대한 정확한 예측이 어려운 실정이다. 따라서 외부 오염부하의 강우시 유입과 퇴적물로부터의 영양염용출 등의 내부 오염부하가 함께 고려된 수질예측기법의 적용이 필요하다. 수몰지 토양 및 호내로부터의 내부부하에 있어서는 퇴적물 내의 다량 존재하는 오염물이 재용출 되거나 퇴적물 내의 화학적 생물학적 반응이 하천 수질에 악영향을 미치게 된다. 대부분 수몰지토양에서 수층으로 용출되는 유기물의 양은 수층에서 퇴적물로 흡수 또는 침강 되는 것보다 많은 경우도 있으며, 오염된 수계에서는 내부 부하량이 과다할 경우 수질 개선을 어렵게 하는 요인이 되고 있다. 따라서 본 연구에서는 2016년 시험담수 예정지인 신규댐 수몰지를 대상으로 토양에 포함된 유기물이 자연상태에서 수체로 용출되는 특성을 분석하여 수질에 미치는 영향을 검토하고자 한다. 댐 수몰지의 토양 시료는 시험담수전 2016년 7월, 토지이용 유형별로 5개지점(논, 밭, 대지, 임야, 하천)에서 시료를 채집하여 총 36일간 용출실험을 실시하였으며, 수층내 용존산소 조건을 호기성 조건과 혐기성 조건으로 나누어 실험하였다. 수질분석은 COD, T-N, T-P, $PO_4-P$등 9개 항목에 대해 실험기간 중 13회 실시하였다. 토양별 점유면적 대비 일 용출량은(kg/day) COD 63 kg/day, T-N 93.6 kg/day, T-P 5.8 kg/day, $PO_4-P$ 4.6 kg/day 였으며, 수몰지 내 토지이용현황별 오염원 기여율은 임야, 밭, 하천, 논, 대지 순 이었다. 본 실험은 수몰지토양의 순수용출량만을 담수개시~36일간 측정한 결과로서 실제 저수지환경에서는 실험값보다 낮을 것으로 판단되며, 수중 수질환경 변화 및 퇴적물의 퇴적 등으로 인하여 원토양으로부터의 용출로 인한 수질에의 영향은 시간의 경과와 함께 변화 또는 감소될 것으로 예상된다. 따라서 본 실험결과는 담수초기의 영향으로 국한하여 해석하는 것이 바람직하며, 보다 장기적인 영향파악을 위해서는 담수 후의 퇴적물의 거동(퇴적현황) 파악 및 담수 후 퇴적물의 장기용출실험을 통한 용출량 검토가 필요하다.

• Korean Journal of Environment and Ecology
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• v.33 no.2
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• pp.228-236
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• 2019

This study investigated the effect of the sediment phosphorus fraction sampled from the southern coast of Korea on the release characteristics of sediments by environmental changes of water quality. We conducted the release experiment in the laboratory for 20 days and measured the phosphorus fraction properties, the environmental factors of water quality, and the release rate of total phosphorus. The results showed a decrease in dissolved oxygen by the growth of microorganisms in the water layer, leading to the anaerobic condition in which the redox potential of the sediments decreased. As such, the decreasing variability of phosphates bonded to iron oxide in the sediment phosphorus was higher after 20 days of the release experiment than the first day. It means that the metal ions and the separated inorganic phosphorus transfer into the water when the iron oxide is reduced. The separated inorganic phosphorus is easily absorbed by the plankton. The analysis of total phosphorus in the water layer showed that it continuously increased to up to 0.304 mg/L for 20 days, and the release rate had a high correlation with the decrease of dissolved oxygen after 5 days of culture. Therefore, it is necessary to pay attention to the characteristics of iron bonded to phosphorus in the phosphorus fraction and dissolved oxygen to manage the eutrophication of the system.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.295-301
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• 2008

Bathymetric data collected using a multi-beam echo sounder during marine scientific survey is essential for geologic and oceanographic research works. Accurate measurment of sound velocity profile(SVP) in water-column is important for bathymetric data processing. SVP can vary at different locations during the survey undertaken for wide areas. In addition, an observational error can occur when different equipments(Sound Velocity Profiler, Conductivity Temperature Depth, eXpendable BathyThermograph) are used for measuring SVP at the same water column. In this study, we used an MB-system software to show changes in bathymetry caused by variation of SVP. The analyses showed that the sound velocity(SV) changes due to the depth and thickness of thermocline had more significant effects on the resulting bathymetric data than those of surface mixed layer. The observational errors between SVP measuring instruments did not cause much differneces in the processed bathymetric data. Bathymetric survey line is better to be established to the direction that the change of temperature can be minimize to reduce the variation of SVP during the data acquisition along the survey line.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.164-164
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• 1996

생약(5kg)을 분말로 한 뒤, MeOH 4$\ell$로 24시간, 2회, 환류추출, 추출액을 감압 농축하여 MeOH ex. (450g)을 얻었다. 이것을 물에 현탁시켜 헥산, 벤젠, 에틸아세테이트, 수층으로 분획, L1210 세포에 대하여 이들 분획물과 vincristine의 병용효과를 관찰하였다. 그 결과, 벤젠분획물에서 강한 효과가 있었으므로 컬럼크로마토그라피하여 물질을 분리하였다.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.27-28
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• 2000

일반적으로 과학어군탐지기는 임의의 수층에서 어군에 의해 산란된 신호로부터 자원량 추정을 실시한다. 따라서, 대상 어군을 구성하는 개체어의 표적강도(Target Strength ; TS)는 가장 중요한 변수이며, 이로부터 현장에서 어군의 분포 밀도를 좀더 정확하게 추정할 수 있다. TS를 결정하는 변수는 자세각, 어체의 체장, 부레의 유무, 주파수 등이다. TS를 알기 위한 많은 국내ㆍ외의 실험들이 죽은 어체를 이용하였으며, 살아있는 어체라도 음축으로부터 어체의 위치를 정확히 파악하기 어려운 센서들을 사용하여 정확한 TS의 정보를 제공하는데는 한계가 있었다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.139-139
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• 2002

금강 하구 연안에서 2001년 4월부터 10월까지 월 2회씩 관측 및 분석한 자료를 가지고, 금강 하구 연안역의 해황과 관련하여 영양염, 부유물질 및 chl-a의 분포 특성을 살펴보았다. 담수 유출이 없을 때에는 금강 하구 연안에서 조석 주기에 따른 수층의 성층과 혼합이 교대로 반복되지만, 담수의 유출이 있을 경우에는 조석 강도에 관계 없이 금강 하구에서 저염수가 표층에 잔존하며 성층을 유지하고 있었다. (중략)