• 한국해안·해양공학회논문집
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• 제20권2호
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• pp.212-218
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• 2008

입사파의 파군에 의해 생성되는 장파는 항내에서 부진동의 문제를 발생시킬 가능성이 있다. 다변수 섭동법을 사용하여 구속장파와 자유장파로 구성된 2차 장파에 관한 지배 방정식의 해석 해를 유도하였다. 자유 장파의 경우 천해역에서의 파속도로 진행하는 반면 구속 장파의 경우 군속도로 진행한다. 장파의 의한 공명을 조사하기 위하여 사다리형태로 변화하는 지형을 고려하였다. 파의 입사각, 수심, 또는 유속에 의하여 자유 장파의 갇힘과 공명현상이 발생하였다.

• 한국자원식물학회지
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• 제26권3호
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• pp.347-354
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• 2013

Apple and pear are popular fruits consumed in Korea and are common fruit in daily diet. In order to compare the antioxidant activity of the apple and pear peels, total polyphenol contents, total flavonoid contents, $ABTS^+$ free radical scavenging activity, and DPPH free radical scavenging activity were measured from hot water, ethanol, and methanol extracts of the two fruit peels. The total polyphenol and flavonoid contents were highest in 95% methanol extracts of the apple peelsand 70% ethanol extract of the pear peels, respectively. Total polyphenol contents of the pear peels were higher than that of apple peels, and total flavonoid contents of the apple peels were higher than that of pear peels. The apple and pear peels had the highest $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity in 95% methanol extracts and 70% ethanol extracts, respectively. $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity of pear peels was higher than that of apple peels, and the DPPH free radical scavenging activity of apple and pear peels were detected in hot water, 95% methanol, and 70% ethanol extracts, respectively. Ascorbic acid, a synthetic antioxidant used as positive control, had significantly higher scavenging activity than the apple and pear peels. In conclusion, the apple and pear peelshave great potential as natural antioxidants. Therefore, above results should be considered to provide the possibility for the development of high functional antioxidants.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.326-334
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• 2010

In this study, we provide a comprehensive review of the CIP(Constrained Interpolation Pro file/Cubic Interpolated Propagation) method with a pressure-based algorithm that is known as a general numerical solver for soled liquid, gas and plasmas. And also we introduce a body-fitted grid system(Soroban grid) for computation of strongly nonlinear marine hydrodynamic problems such as slamming water on deck, wave impact by green water. This grid system can keep the third-order accuracy in time and space with the help of the CIP method. The grid system consists of the straight lines and grid points. In the 2-dimensional grid case, each grid points moving in these lines like abacus - Soroban in Japanese. The length of each line can be different and the number of grid points in each line can be different. Mesh generation and searching of upstream departure point are very simple and possible to mesh-free treatment. To optimize computation of free-surface and multi-fluid flows, We adopt the C-CUP method. In most of the earlier computations, the C-CUP method was used with a staggered-grid approach. Here, because of the mesh free nature of the Soroban grid, we use the C-CUP method with a collocated-grid approach.

• 동아시아식생활학회지
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• 제25권4호
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• pp.681-690
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• 2015

In this study, gluten-free noodles were developed and the physicochemical quality of gluten-free noodles added with nondigestible maltodextrin (NMD) was also investigated. The gluten-free noodles were prepared by addition of 0, 5, 7, and 9% NMD of total ingredients except water. Inhibition activities for ${alpha}$-amylase and ${alpha}$-glucosidase according to the addition amounts of NMD were evaluated. As a result, activities of carbohydrate-digestive enzymes decreased with an increase of the added NMD amounts. Water binding capacity and solubility of raw noodles increased upon NMD addition. Swelling power also increased as temperature rose. L value of raw noodles decreased with the addition of NMD, but b value increased. Texture profile analysis of cooked noodles showed reduction of hardness, springiness, and chewiness of noodles with NMD. On the other hand, tensile strength of cooked noodles containing up to 7% NMD was not significantly different from that of noodle without NMD. In the sensory evaluation, elasticity of noodles with 9% NMD was lower than that of other noodles, whereas other characteristics of noodles were not significantly different among noodles. Therefore, it was confirmed that the addition of 5~7% NMD had little effect on the sensory quality of noodles.

• 접착 및 계면
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• 제4권4호
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• pp.1-6
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• 2003

대기압 플라즈마를 이용하여 폴리프로필렌 필름의 표면을 처리한 후 각각 극성 용매(water)와 비극성 용매(diiodomethane)를 사용한 접촉각 측정기로 필름 표면의 접촉각을 측정하였다. 측정된 접촉각을 이용해 표면 자유에너지 변화를 계산한 후 대기압 플라즈마 처리 전후의 폴리프로필렌 필름의 접촉각과 표면 자유에너지 상태를 비교, 분석하였다. 또한 대기압 플라즈마의 처리 조건을 바꿔가며 폴리프로필렌 필름 표면을 처리함으로써 접촉각과 표면 자유에너지가 각각의 처리 조건에 따라 어떠한 영향을 받는지 연구하였다. 대기압 플라즈마 처리 조건에 따라 접촉각 및 표면 자유에너지는 최적값을 보여주거나 일정한 값에 도달하는 경향을 보여 주었다.

• 한국전산유체공학회지
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• 제4권1호
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• pp.1-7
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• 1999

The numerical methodology for computing tile impact forces and water entry behaviors of high speed water entry bodies was been developed. Since the present method assumed the impact occurs within a very short time interval. the viscous effects do not have enough time to play a significant role in the impact forces, that is, the flow around a water-entry object was assumed as an incompressible potential flow and is solved by the source panel method. The elements fully submerged into the water are routinely treated, but the elements intersected by the effective planar free surface are redefined and reorganized to be amenable to the source panel method. To validate the present code, it was applied to disk, cone and ogive model and compared with experimental data. Good agreement was obtained. The water entry behavior such as the bouncing phenomena from the free surface was also simulated using the impact forces and two degree of freedom dynamic equation. Physically acceptable results were obtained.

• 한국물환경학회지
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• 제26권5호
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• pp.781-788
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• 2010

A pilot study was performed to examine the feasibility of multiple stage of constructed wetland (CW) for nutrient removal. The system is composed of six wetland cells connected with water-ways. The hydraulic of wetland cells is designed as free water surface flow. The treatment capacity was $25m^3d^{-1}$ at HRT of about one day for each cell. The magnitude of nutrient removal was related with the length of wetlands and plant density. Total N and P removal rates were 1353 and $246mg\;m^{-2}d^{-1}$ respectively. The pilot-scale reactor was model as continuous flow system containing contribution of CSTR and PFR typed-reactors. The $k-C^*$ model equation was applied to predict N and P reduction. The result indicated the equation was well guided to estimate reduction of $NO_3-N$ and $PO_4-P$.

• 대한조선학회논문집
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• 제36권4호
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• pp.37-47
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• 1999

본 논문에서는 접수(water entry) 및 이수(water exit) 문제를 유동장의 지배방정식인 2차원 비압축성 Navier-Stokes방정식을 일반좌표계(generalized coordinate system)에서 유한체적법(Finite Volume Method)으로 이산화 하여 해석하였다. 강체의 접수 또는 이수 상황에서 발생하는 자유수면 변형에 대한 처리는 Level-Set[11]기법을 사용하였다. 수치계산결과에서 접수에 대한 유체충격력에 대한 계산결과는 쐐기(wedge)형과 flared-ship 단면의 실험결과[5]와 비교하였으며, 원형실린더의 이수문제에서는 시간에 따른 자유수면의 변형 및 유동장의 특징을 살펴보았다.

• Bulletin of the Korean Chemical Society
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• 제24권8호
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• pp.1211-1214
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• 2003

The anomalies that appear at every multiple of 15 ℃ in the viscosity of a thin liquid film of water and of water near solid interfaces are explained in this paper by comparing the thermal wavelength and molecular free volume of water, and quantum numbers are found. The possibility that these anomalies are related to the preferred and/or lethal temperatures of organisms is considered. The toxicity of heavy water (D₂O) can also be explained with this approach.

• 한국식품영양과학회지
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• 제19권2호
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• pp.133-142
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• 1990

This study was attempted to compare the nutritive value of leaf with stem of the water cress Oenanthe stolonifera DC. in order to improve the eating habits and as a part of studying on the effective curing nutrients for the damaged liver. The contents of moisture crude proteinon the effective curing nutrients for the damaged liver. The contents of moisture crude protein crude fat and crude ash were 90.40% 2.85%, 0.42% and 0.74% in leaf while the contents of moisture crude protein crude fat and crude ash were 95.15% 0.77% 0.09%, and 0.64% of moisture crude protein crude fat and crude ash were 95.15% 0.77% 0.09% and 0.64% in stem respectively. The quantitative fractionation of proteini of both leaf and stem ranked albumin the highest content followed globulin prolamin and glutelin in order. It has been sh-own by SDS-polyacrylamide gel electrophoresis that water extractable protein of leaf 11 bands but those of stem were not detected. The scope of molecular weight for the main protein of water extractable protein of leaf was between 34.700 and 45,000. The amounts of extractive-nitrogen from leaf and stem of the water cress were 241.02mg% and 271.67mg% respec-tively. The amounts of free amino acid-nitrogen from the leaf and stem were 89.02mg% and 32.02mg% respectively. In free amino acid-nitrogen from the leaf and stem were 89.02mg% and 32.02mg% respectively. In free amino acid composition of both leaf and stem the major components were aspartic acid and glutamic acid. In total amino acid composition of water cress leaf aspartic and glutamic acid were the major components. Whereas alanine and thr-eonine were the major components in stem The assessment of water cress leaf and stem with chemical score. EAAl Rl showed that the values of stem were lower tendancy than those of leaf. Limiting amino acid of leaf was tryptophan while that of stem was lysine.