• Title/Summary/Keyword: 액체의 얇은 막

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A CPU and GPU Heterogeneous Computing Techniques for Fast Representation of Thin Features in Liquid Simulations (액체 시뮬레이션의 얇은 특징을 빠르게 표현하기 위한 CPU와 GPU 이기종 컴퓨팅 기술)

  • Kim, Jong-Hyun
    • Journal of the Korea Computer Graphics Society
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    • v.24 no.2
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    • pp.11-20
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    • 2018
  • We propose a new method particle-based method that explicitly preserves thin liquid sheets for animating liquids on CPU-GPU heterogeneous computing framework. Our primary contribution is a particle-based framework that splits at thin points and collapses at dense points to prevent the breakup of liquid on GPU. In contrast to existing surface tracking methods, the our method does not suffer from numerical diffusion or tangles, and robustly handles topology changes on CPU-GPU framework. The thin features are detected by examining stretches of distributions of neighboring particles by performing PCA(Principle component analysis), which is used to reconstruct thin surfaces with anisotropic kernels. The efficiency of the candidate position extraction process to calculate the position of the fluid particle was rapidly improved based on the CPU-GPU heterogeneous computing techniques. Proposed algorithm is intuitively implemented, easy to parallelize and capable of producing quickly detailed thin liquid animations.

Model prediction of crosslinked chitosan composite membrane for pervaporation of water-ethanol mixtures

  • 박호범;남상용;이영무
    • Proceedings of the Membrane Society of Korea Conference
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    • 1996.04a
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    • pp.65-66
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    • 1996
  • 투과증발법은 상부에 액체공급액이 반투과막과 접촉하고 있고 하부에 진공에 가까운 낮은 압력을 걸어줌으로써 투과물이 수증기로 제거되는 막공정의 하나이다. 막을 통한 분리는 혼합물의 각 성분이 막내에서 다른 용해도와 확산도를 가지고 있기 때문에 발생한다. 이 공정의 지배적인 전달 메카니즘은 용해-확산 모델을 기초로 하고 있기 때문에 전형적으로 투과증발막은 대개 미세다공성 지지체에 얇은 선택성을 가진 재료를 입힌 복합막을 사용한다. 본 연구의 목적은 선택성을 가진 상부층막이 키토산인 복합막에서 지지체 구조의 영향을 살펴보고 키토산 복합막에 대한 물-에탄올 분리에 대해 최적의 모델을 찾는 것이다. 투과증발막소재로서의 키토산은 친수성기를 가지고 있으므로 물과 알코올의 분리에서 물만을 선택적으로 흡수하여 투과시키는 우수한 성능을 지니고 있으나 더욱 효과적인 막성능을 발휘하기 위해서는 지지체의 역할 및 막성능에 영향을 끼치는 여러 가지 인자들을 고려해서 막을 설계하는 것이 필요하다. 여기서는 상부층의 막두께, 지지체의 특성, 피드 농도 등을 변화시켜 가장 적당한 모델을 예측하였다.

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Preparation of Hydrophilic-Hydrophobic Composites by A Concentrated Emulsion Polymerization Method and Their Permselectivity to Mixture of Water-Ethanol (고농축에멀션중합방법을 이용한 분리막제조와 선택적 흡수성 연구)

  • Park, Jun-Seo
    • Applied Chemistry for Engineering
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    • v.8 no.1
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    • pp.29-38
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    • 1997
  • In the w/o concentrated emulsion, the volume fraction of the dispersed is greater than 0.74 and the hydrophilic liquid is dispersed in the hydrophobic liquid of the continuous phase. The emulsion has the same appearance and behaviour as a gel. The polarity of the hydrophilic liquids and hydrophobic liquids, the pH and the ionic strength of the hydrophilic liquid are found to be important factors in the stability at the polymerization temperature such as $50^{\circ}C$. The lower the polarity of the hydrophobic liquid and the higher the polarity of the hydrophilic liquid, the more stable the emulsion. Electron microscopy studies of the hydrophilic-hydrophobic polymer composites show that the particles of polyacrylamide, the dispersed phase, are separated by he network of the thin film of polystyrene, the continuous phase. This hydrophilic-hydrophobic polymer composites show higher permselectivity to water in the mixture of water-ethanol. The pervaporation experiment shows that the selectivity of the membrane ranges between 4-40 and increases with increasing enthanol concentration in the feed. The rate of permeation decreases with increasing ethanol concentration in the feed.

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Gartner´s Duct Cyst in a Maltese Bitch (말티즈 암캐에 있어 Gartner´s Duct 낭종례)

  • 정원일;이차수;박상준;정규식
    • Journal of Veterinary Clinics
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    • v.18 no.2
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    • pp.182-184
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    • 2001
  • 2001년 4월 19일에 11살 된 말티즈 암캐의 비정상적 자궁에 대한 검사의뢰가 들어왔다. 육안적 검사에서 얇은 막으로 된 다양한 자궁 낭종이 관찰되었다. 그 수는 5개이며 그중 2개는 자궁체의 장막면에 위치하고 있었으며 7∼8 mm 정도의 직경을 가지고 있었다. 나머지 3개는 직경 1∼2 mm 정도의 크기이며 자궁각의 장막면에 위치하고 있었고, 절개시 모든 낭종들은 장액성 액체들로 가득 차 있었다. 병리조직학적 검사에서는 모든 낭종들이 자궁의 장막하에 존재하고 있었다. 낭종의 상피세포들과 이들의 위치는 모두 Gartner's duct와 동일한 것들이었고, 따라서 Gartner's duct cyst로 진단하게 되었다.

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Research Activities of Transpiration Cooling for High-Performance Flight Engines (고성능 비행체 엔진을 위한 분출냉각의 연구동향)

  • Hwang, Ki-Young;Kim, You-Il
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.10
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    • pp.966-978
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    • 2011
  • Transpiration cooling is the most effective cooling technique for the high-performance liquid rockets and air-breathing engines operating in aggressive environments with higher pressures and temperatures. When applying transpiration cooling, combustor liners and turbine blades/vanes are cooled by the coolant(air or fuel) passing through their porous walls and also the exit coolant acting as an insulating film. Practical implementation of the cooling technique has been hampered by the limitations of available porous materials. But advances in metal-joining techniques have led to the development of multi-laminate porous structures such as Lamilloy$^{(R)}$ fabricated from several diffusion-bonded, etched metal thin sheets. And also with the availability of lightweight, ceramic matrix composites(CMC), transpiration cooling now seems to be a promising technique for high-performance engine cooling. This paper reviews recent research activities of transpiration cooling and its applications to gas turbines, liquid rockets, and the engines for hypersonic vehicles.

Lipids and Fatty Acid Composition of Barley Grain (보리의 지방질 성분에 관한 연구)

  • Shin, Hyo-Sun;Gray, J. Ian
    • Korean Journal of Food Science and Technology
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    • v.15 no.2
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    • pp.195-201
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    • 1983
  • Lipids isolated from three barley samples were identified and quantitated by column, thin layer and gas liquid chromatographic techniques. These lipids were shown to consist of 69.3-73.1% neutral lipids, 9.6-16.5% glycolipids, and 14.2-17.9% phospholipids. Among the neutral lipids, triglycerides were predominant (54.2 to 55.7%) with smaller amounts of 1,2-diglycerides, 1,3-diglycerides, free sterols, free fatty acids, steryl esters, and three unknown being present. Among the glycolipids, digalactosyl diglycerides (31.3 to 33.2%) and monogalactosyl diglycerides (26.2 to 29.6%) were the most abundant. Esterified steryl glycosides, steryl glycosides, cerebrosides, sulfolipids, and an unknown component were present as minor components. Of the phosopholipids, phosphatidyl cholines and serines, lysophosphatidyl cholines, and phosphatidyl ethanolamines were the major components, comprising over 80% of this class. The major fatty acids in the total and the three lipid classes were palmitic, oleic, linoleic and linolenic acids. However, the neutral lipids fraction contained more oleic acid than other lipid fractions, and the phospholipids fraction contained more palmitic acid than the other lipid fractions.

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Studies on the Lipid Components of Panax ginseng (인삼(人蔘)의 지방질(脂肪質) 성분(成分)에 관한 연구)

  • Shin, Hyo-Sun;Lee, Min-Woong
    • Korean Journal of Food Science and Technology
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    • v.12 no.3
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    • pp.185-192
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    • 1980
  • To study lipid components of Panax ginseng produced in Korea, the lipids of fresh ginsengs were extracted with the mixture of chloroform-methanol (2:1, v/v) and those of dried ginsengs were extracted with diethyl ether respectively. The lipid components extracted were separated and quantitated by column, thin layer and gas-liquid chromatographies. The results were summarized as follows : 1. Fresh ginseng contained 0.62% total lipid of which 45.28% were neutral lipids, 18.12% glycolipids, and 36.60% phospholipids. But dried ginseng contained 0.89% total lipids of which 86.48% were neutral lipids, 9.20% glycolipids, and 4.32% phospholipids. 2. Triglycerides (37.6 to 42.5% of the total neutral lipids) and sterol esters (16.5 to 19.6%) in all the fresh and dried ginseng were the major components among the neutral lipids. Monoglycerides, diglycerides, free fatty acids and free sterols were minor components. 3. Digalactosyl diglycerides (23.5% of the total glycolipids) in the fresh ginseng and steryl liglycosides (28.9%) in the dried ginseng were predominant components among the glycopids, respectively, Esterified steryl glycosides and monogalactosyl diglycerides were also identified, and four unknown spots in the fresh ginseng and two unknown spots in the dried ginseng were present. 4. Phosphatidyl cholines (31.3 to 31.9% of the total phospholipids) and phosphatidyl glycerols (34.8 to 36.7%) in all the fresh and dried ginseng were the major components among the phospholipids. Phosphatidyl inositols and phosphatidyl ethanolamines were also identified. 5. The major fatty acids in the fresh and dried ginseng were linoleic $(62.29{\sim}64.32%)$, palmitic $(13.16{\sim}15.63%)$, oleic $(5.73{sim}7.23%)$ and linolenic $(5.73{sim}7.23%)$. The fatty acid compositions in neutral lipid fraction was similar to the pattern in those of the total lipids. But glycolipid and phospholipid fractions contained a lower percent of linoleic acid and a higher percent of palmitic acid than the neutral lipid fraction.

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