• Journal of Ocean Engineering and Technology
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• v.22 no.4
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• pp.20-26
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• 2008

The primary purpose of this study was to quantitatively examine whether there was a difference in the settling velocities of cohesive sediments in the Saemankeum artificial lake before and after the closure of the Saemankeum seadike. Through in situ sediment sampling and laboratory experiments, the settling velocities were estimated as a function of the suspension concentration and their physico-chemical properties, such as grain size distribution, the percentage of organic contents, mineralogical composition, etc. were also examined. In this study, their inter-relation with settling velocities were also analyzed qualitatively. The result of the settling tests for Saemankeum sediments showed that there was a big difference in the settling velocities before and after the closure of the Saemankeum seadike. Its settling velocities in a flocculated settling region became remarkably larger after the closure compared to those before the closure, while they were similar but relatively smaller in a hindered settling region. This was found to be mainly due to the difference in their grain size.

• KSBB Journal
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• v.10 no.2
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• pp.166-169
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• 1995

Spores of Trichoderma harzianum TCC 52445 for control of Rhlzocronia stem canker on potato were immobilized in various natural matrix, and germination rate and some rheological properties of the spore-matrix complex were Investigated. Germination rate of gelatin gel-spore complex and potato starch gel-spore complex were 2.8% and 2.9%, respectively, but hardness and cohesiveness of the gelstin gel-spoke complex were better than those of potato starch-spore complex. The hardness and cohesiveness were increased when the spores were immobilized in hybrid gelatin gel made by mixing several different types of natural matrix, but decreased their germination rate. Addition of corn steep liquor (1%) as spore nutrient in gelatin gel-spore complex was helpful for increasing the germination rate.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.217-220
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• 2005

햄버거 패티에 기능적 특성을 부여하고자 실크 펩타이드를 첨가하여 햄버거 패티를 제조한 후 품질특성 및 최적 실크 펩타이드 첨가량을 평가하였다. 실크 펩타이드가 햄버거 패티의 가열 감량에 미치는 영향을 분석한 결과 실크 펩타이드 첨가량이 증가함에 따라 가열감량이 유의적으로 감소하는 것으로 나타났다. 실크 펩타이드가 첨가된 햄버거 패티의 경도, 탄성 및 점착성을 분석한 결과 경도는 실크 펩타이드 첨가량이 증가함에 따라 감소하는 경향이었으나, 탄성과 점착성의 경우 실크 펩타이드 첨가에 의해 영향을 받지 않는 것으로 나타났다. 또한, 색도 측정결과 실크 펩타이드 첨가량이 증가함에 따라 명도(L) 및 적색도(a)는 유의적으로 증가하였으며, 황색도(b)는 감소하는 것으로 나타났다. 실크 펩타이드를 첨가한 햄버거 패티의 관능적 특성을 분석한 결과 실크 펩타이드가 첨가된 햄버거 패티는 외관, 후각, 미각, 조직감 및 종합적 기호도 등 모든 평가항목에서 무첨가구에 비해 높게 나타났다.

• Journal of Ocean Engineering and Technology
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• v.20 no.4 s.71
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• pp.37-42
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• 2006

This paper is concerned with experimental investigation of steering performance of a tracked vehicle on extremely soft soil. A tracked vehicle model with principal dimensions of 0.9 m(L)x0.75 m(B)x0.4 m(H) and weight of 167 kg was constructed with a pair of driving chain links, driven by two AC-servo motors. The tracks were configured with detachable grousers with variable span. A deep seabed was simulated by means of a bentonite-water mixture in a soil bin of 6.0 m(L)x3.7 m(B)x0.7 m(H). The turning radii of vehicle and driving torques of motors were measured with respect to experiment variables: steering ratio, driving speed, grouser chevron angle, grouser span, and grouser height. L8 orthogonal table is adopted for DOE (Design of experiment). The effects of experiment variables on steering performance are evaluated.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.76-81
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• 2008

UV curable pressure sensitive adhesive (PSA) was made by blending the di-functional or hexa-functional urethane-acrylate oligomer with synthesized acrylic PSA. The change of adhesive property and removability were investigated at various oligomer contents under each oligomer. As the content of oligomer increased, the peel strength was increased before UV irradiation, but it was decreased after UV irradiation. Also, it was observed that the peel strength increased with decrease of storage modulus (G'), and that loss factor (tan ${\delta}$) of the adhesive material affected the adhesive properties and removability.

• Korean journal of food and cookery science
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• v.17 no.1
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• pp.1-6
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• 2001

The purpose of this study was to investigate sensory and mechanical characteristics of Surichwi-injeulmi by adding Surichwi contents. According to sensory evaluation of Surichwi-injeulmi, the acceptance was the best in the color, flavor and overall quality when adding 20% Surichwi. As the additional ratio of Surichwi was increased, the lightness and yellowness were decreased, however, the redness was negatively increased. As a results of textural analysis of Surichwi-injeulmi by adding Surichwi contents in storing at 20$\^{C}$, the hardness, chewiness, gumminess and cohesiveness were decreased with the increased by adding Surichwi contents. The hardness, chewiness, gumminess and cohesiveness were decreased by increased storage time, whereas the elasticity was increased. Textural characteristics of Surichwi-injeulmi added 30% and 40% Surichwi in storing at 20$\^{C}$ showed less change than those of 0 and 10% group.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.3
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• pp.197-215
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• 2003

This study was carried out to investigate the effects of added emulsifier and enzyme on the quality characteristics of Seolgiddeok with black rice powder, green tea powder, Lentines edodes powder, pumpkin powder during storage. Samlpes were divided into two groups, the emulsifier-enzyme added group and the control, and stored fur 4 days at 2$0^{\circ}C$. Moisture content was measured by the air oven method; the Hunter's cole. values by Lightness (L), redness (a), yellowness (b) value; the degree of gelatinization by the enzyme digestion method, and expressed as glucose content by Somogi-Nelson method. The degree of retrogradation was calculated as the retrogradation rate using the degree of gelatinization value, and total cell and mold counts were also measured. Texture and sensory characteristics were also investigated. The results are as follows: The emulsifier-enzyme group was significantly different from the control from each examination and the retrogradation of pumpkin Seolgiddeok with emulsifier-enzyme was delayed the most among samples tested.

• Polymer(Korea)
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• v.36 no.2
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• pp.182-189
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• 2012

In this study, poloxamer hydrogels were prepared by electron beam irradiation and evaluated for potential application as a buccal mucoadhesive drug delivery system. Poloxamer, one of typical thermoresponsive polymers, was modified to have vinyl end groups for crosslinking reaction, and its hydrogels were fabricated by irradiation crosslinking reaction. Carbopol as a mucoadhesive polymeric additive was introduced to improve the mucoadhesive property of the hydrogels and its effect on the mucoadhesion and drug release properties was investigated. The results showed that the end group modification of poloxamer and the addition of carbopol improved mucoadhesive force and mechanical properties and led to a sustained drug release behavior.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.909-914
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• 2008

미세-점착성 퇴적물로 구성되는 퇴적저면의 침식특성을 해석하기 위해, 고령토 퇴적저면에 대한 침식실험이 환형수조를 이용하여 수행되었다. 현재, 퇴적저면의 침식특성 연구에 대한 국내사례는 전무한 실정으로, 본 연구는 퇴적저면에 대한 침식실험 방법 및 결과의 타당성 검증을 목적으로 한다. 이를 위하여, 본 연구에서는 압밀시간 조건에 따라 4가지의 서로 다른 퇴적저면이 조성되었고, 각 저면별로 저면깊이에 따른 저면밀도의 변화가 우선적으로 정밀 측정되었다. 각 퇴적저면별 침식실험으로부터는, 바닥전단응력(${\tau}_b$)의 변화에 따른 저면 침식깊이(즉, 수층 부유사 농도)의 변화 측정을 통하여, 저면깊이에 따른 저면전단강도(즉, 침식한계전단응력, ${\tau}_S$)의 변화 값들이 정량적으로 분석되었으며, 최종적으로 잉여전단응력(${\tau}_b-{\tau}_S$)과 침식률 간의 관계식이 산정되었다. 퇴적저면 침식특성에 관한 과거 해외 연구 결과와의 비교 검토를 통하여, 본 연구에서 사용 혹은 적용된 실험장치, 실험 방법 및 실험결과가 타당성이 있음이 확인되었다.

• Korean Journal of Ecology and Environment
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• v.44 no.1
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• pp.66-74
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• 2011

This numerical study aims to investigate the effect of cohesive sediment on turbulence structure due to density stratification. The transport model for cohesive sediment incorporated with flocculation model has been selected and calculates the concentration, fluid momentum, and turbulence. From the model results, it is known that suspension of sediment decreases turbulence intensity. It is also found that cohesive sediment has a relatively weak effect on turbulence damping compared to noncohesive sediment. The low settling velocity and more suspension of cohesive sediment are considered to be mechanisms of this behavior. Richardson number determined with results of this study quantitatively shows that cohesive sediment causes less stable density stratification condition and, as a result, the turbulence structure is less damped compared to the case of noncohesive sediment.