• 한국해안·해양공학회논문집
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• 제31권3호
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• pp.180-198
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• 2019

최근, 유럽이나 일본 등은 해빈유실방지대책공법의 하나이며, 잠제의 대안으로 여겨지는 저천단구조물(LCS)에 관한 많은 연구를 수행하였고, 그의 결과들을 집약하여 설계매뉴얼까지 편찬하였다. 지금까지 LCS에 관한 연구는 2차원적인 파랑전달율과 피복재의 안정중량산정에 치우쳐 있으며, 이들은 주로 실험에 기초하여 검토 논의되었다. 본 연구에서는 투과성의 LCS를 대상으로 3차원수치해석을 수행한다. 수치해석에 Navier-Stokes 운동방정식에 기반한 오픈소스 CFD Code인 olaFlow를 적용하였으며, 이는 쇄파와 난류해석까지도 가능한 강비선형해석법이다. 이로부터 수위, 흐름 및 난류운동에너지 등의 분포특성을 검토 논의하였으며, 동시에 잠제의 경우와도 비교 검토하였다. 이로부터 해안선 근방에서 연안류의 흐름패턴과 평균난류운동에너지의 연안방향 및 종단방향의 공간분포에 관해 잠제와 LCS의 경우에 각각 차이가 발생하는 것을 알 수 있었다. 이러한 결과의 차이는 모래이동에서의 차이로 이어질 것으로 판단된다.

• Journal of Ginseng Research
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• 제29권3호
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• pp.145-151
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• 2005

식물조직배양기술을 이용하여 Ge를 함유한 인삼 root를 생산하고자, 0.5mg/L BAP와 3.0mg/L NAA조합의 식물생장 조절물질로 유도된 인삼 root를 이용하여 배양을 위한 최적 $GeO_2$농도, $GeO_2$ 첨가시기 및 배지의 pH를 조사하였다. 인삼 root의 생장에 가장 좋은 $GeO_2$ 농도는 10ppm, $GeO_2$ 첨가시기는 배양 초기(0주), pH는 5.5였고, 인삼 root내 Ge의 함량이 가장 높았을 때의 $GeO_2$농도는 100ppm이었다. $GeO_2$를 첨가하여 배양한 기간이 길수록 Ge함량이 증가하였으나 6주 이후부터 생장율이 둔화되어 $GeO_2$ 100ppm에서는 생장율이 아주 낮아 대조구의 1/2 정도였다. 배양 초기에 $GeO_2$를 첨가하여 8주간 배양한 인삼 root의 Ge 함량이 $29.4mg\%$인데 반해, 배양 2주째에 $GeO_2$를 첨가한 인삼 root의 경우는 Ge 함량이 $38.6mg\%$이므로, 배양 후 2주 후에 $GeO_2$를 첨가하는 것이 인삼 root의 Ge흡수에 더욱 효과적이었다. Ge흡수가 가장 잘 이루어지는 최적 pH는 5.5였으며 사포닌 함량은 $GeO_2$의 첨가농도가 증가할수록 감소하였다.

• Journal of Microbiology
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• 제40권4호
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• pp.260-266
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• 2002

Bacterial strains were isolated from biofilms formed on glass slides submerged in seawater in Dae-Ho Dike. Eight strains showing fast attaching ability were selected and identified. Their exopolysaccharide (EPS)-producing ability and EPS properties were characterized. Based on Microlog System, 4 among the 8 strains were identified as Micrococcus luteus and the rest were Bacillus thuringiensis, Bacillus megaterium,, Staphylococcus saprophyticus and Agrobacterium vitis. A, vitis was reidentified as Sulfitobacter pontiacus based on 16S rDNA sequence data. The amount of water-soluble EPS produced by the 8 strains ranged from 0.114 to 1.329 g$.$l$\^$-1/ and the productivity was negatively correlated with the cell biomass. The molecular weight of the produced EPS ranged from 0.38 to 25.19$\times$10$\^$4/ Da. Glucose and galactose were ubiquitous sugar components. Mannose, ribose, and xylose were also major sugar components. The molecular weight and composition of the EPS showed strain-specific variation.

• KSBB Journal
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• 제26권1호
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• pp.33-40
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• 2011

Anti-diabetic effect of the exopolysaccharides (EPS) produced from submerged mycelial culture of Cordyceps sinensis (Cs) was studiedin a type II diabetic animal model (C57BL/6J ob/ob). This study was designed to determine whether Cs-EPS improves clinical symptoms of type II diabetes in ob/ob mice. After Cs-EPS treatment at doses of 200 mg/kg body weight, the fasting blood glucose levels decreased by 47% after 7 weeks compared with those of the control mice. According to the oral glucose tolerance test, the glucose levels recovered its baseline after 120 min in Cs-EPS-treated mice, although the blood glucose levels increased significantly after 30 min. On the other hand, the control group (not-treated) did not recovered its initial level of glucose after 120 min. Furthermore, food intake, body weight, total plasma cholesterol and triglyceride concentrations in ob/ob mice treated with Cs-EPS were significantly decreased, compared with those in control ob/ob mice. Cs-EPS treatment increased significantly the plasma insulin level and the expression of leptin mRNA in adipose tissue of Cs-EPS-treated ob/ob mice. From these results, it is demonstrated that Cs-EPS could be effective for regulating normal blood glucose levels by increasing the amounts of plasma insulin and leptin expression in ob/ob mice, indicating that this compound could be a candidate material as a dietary supplement to control hyperglycemia in patients suffering from type II diabetes.

• Journal of Advanced Marine Engineering and Technology
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• 제40권10호
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• pp.883-887
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• 2016

This study aims to evaluate the corrosion behavior of a newly developed high-strength steel in marine environments. Metals used in seawater are easily deteriorated because of the presence of corrosive species such as chloride ions in it. Seawater causes much higher corrosion than fresh water. Thus, the corrosion of steel in marine environment has been recognized as a crucial problem in designing structures which cannot be cathodically protected. In this study, the corrosion resistance of a newly developed high-strength steel was evaluated. Four different specimens were tested to confirm the corrosion resistance. The exposure corrosion test was carried out by exposing the specimens to different marine environments such as atmospheric, tidal, splash, and submerged zones for two years. The specimens taken out from each location were cleaned ultrasonically and chemically prior to the evaluation of their corrosion resistance by the weight loss method. Finally, the pitting depth of the specimens was also measured to evaluate their pitting corrosion. The conditions used for the corrosion test were similar to the environmental conditions. The corrosion test results revealed that the corrosion rate and pitting corrosion of the newly developed high-strength steel was lower than that of the other carbon steels.

• 대한토목학회논문집
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• 제33권5호
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• pp.1887-1895
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• 2013

이 연구에서는 2차원 조파수조에서 수리모형실험을 실시하여 수중터널 모형의 수리학적, 구조적 성능을 고찰하였다. 수심 및 부력 대 자중비를 다양하게 변화시킨 조건에서 파고 및 주기가 서로 다른 규칙파를 조파하여 실험을 수행하였다. 실험 자료의 분석을 통해서 연직방향 및 횡방향 동요가 파고 및 주기에 따라 선형적으로 증가함을 확인하였다. 반면에, 회전 운동의 크기는 파고 및 주기가 설계파 정도로 커지지 않으면 별로 크게 나타나지 않았다. 마찬가지로, 계류장력 및 수중터널에 작용하는 파력도 파고 및 주기에 따라 선형적으로 증가하였다. 수심 및 부력 대 자중비의 변화와 관련해서는, 구조적 거동 및 수중터널에 작용하는 파력의 크기 모두 수심 증가 및 부력 대 자중비 감소에 따라서 전체적으로 감소하는 경향이 나타났다.

• 한국균학회지
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• 제33권2호
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• pp.64-68
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• 2005

Streptozotocin으로 당뇨가 유발된 흰쥐에 차가버섯 균사체를 2주간 체중 ka당 200 mg으로 경구투여시킨 후 혈장 glucose, total cholesterol, triglyceride, ALT, 및 AST 활성을 관찰하였고, 차가버섯 균사체의 일반성분을 조사하였다. 그 결과 체증증가는 당뇨 대조군에 비해 약 23.5% 증가하였고, 식이섭취량은 21.0% 낮게 나타났으며, 간장 무게는 18.1% 정도 감소하였다. 혈장 glucose 농도는 차가버섯 균사체 투여군이 당뇨 대조군보다 23.1%가 유의하게 감소하였으며, 혈장 total cholesterol과 triglyceride는 각각 12.6%와 22.6%로 낮게 나타났다. 또한 혈장 ALT와 AST 활성은 당뇨 대조군에 비해 차가버섯 균사체 투여군이 27.6%와 21.9% 낮은 활성을 보였다. 상기와 같은 항당뇨 활성을 가진 차가버섯 균사체의 일반성분을 분석한 결과 조회분 5.55%, 조지방 2.35%, 조단백 28.29%, 탄수화물 9.53% 및 식이섬유 54.28%로 구성되어 있었다.

• Mycobiology
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• 제29권3호
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• pp.160-163
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• 2001

Sikhae is a Korean traditional beverage of saccharified rice. Its factory waste(SFW) is usually thrown away instead of being used. We developed a cheap substrate of SFW for use in liquid spawn that is known for its higher fruit body yields than grain spawn in sawdust cultivation. Mycelia of Lentinula edodes ASI 3046, which is regarded as the most suitable strain for sawdust cultivation, were cultured on six kinds of previous known media and SFW. As the seven kinds of media were applied, a Sikhae Factory Waste(SFW) was most excellent in growth. The dried mycelial weight in SFW was almost four times as much as that in the other media. In the flask culture, optimum culture conditions for the mycelial growth were obtained after 13 days of cultivation at media volume of 100 ml, 100 rpm, initial pH 4.5, and $25^{\circ}C$. The best mycelial growth was observed when $MgSO_4{\cdot}7H_2O$ and D-sucrose were added as a supplement in SFW. SWM must be a remarkable medium for L. edodes because of its simple preparation and low cost.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.367-370
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• 2002

A neutral polysaccharide, GP, was isolated from a fermentation broth of Ganoderma lucidum Acid hydrolysis and a paper chromatography analysis indicated that the polysacchride was composed of glucose, xylose, and mannose. The molecular weight was estimated to be $2.9{\times}10^4$. The oral administration of GP to mice showed that it can inhibit liver damage induced by GalN and $CCl_4$.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.344-350
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• 2001

Piping is a phenomenon where seeping water progressively erodes or washes away soil particles, leaving large voids (Pipes led to the development of channels) in the soil. Piping failure caused by heave can be expected to occur on the downstream side of a hydraulic structure such as fill dams when the uplift forces of seepage exceed the downward forces due to the submerged weight of the soil. The way to prevent erosion and piping and to reduce damaging uplift pressures is to use a protective filter or to construct cutoff wall/imperious blanket. Therefore, all the hydraulic structures faced/with soil materials should be taken the safety against piping into consideration.