• Title, Summary, Keyword: surface tension

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The Surface Tension and the C. M. C. of the Solution of Dodecylpyridinium Bromide (Dodecylpyridinium Bromide 溶液의 表面張力과 C. M. C.)

  • Han, Man-Un;Lee, Chong-Man;Kim, Tae-Woo
    • Journal of the Korean Chemical Society
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    • v.9 no.3
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    • pp.124-127
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    • 1965
  • The surface tension of the solution of dodecylpridinium bromide was measured by the ring method over the range $25^{\circ}\; to\; 45^{\circ}C.$ The critical micelle concentration was determined from the change of the surface tension of solution with concentration. The temperature dependence of the critical micelle concentration was also investigated. The result was compared with Adderson and Taylor's data determined by the conductivity method.

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A Study on the Shape Finding and Patterning Procedures for Membrane Structures (막구조의 초기형상 및 재단도 결정알고리즘에 관한 연구)

  • 한상을;이경수;이상주;유용주
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.298-305
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    • 1998
  • The purpose of this study is to propose the method of determining the initial fabric membrane structures surface and membrane patterning procedures. Tension structure, such as, fabric membrane structures and cable-net, is stabilized by their initial prestress and boundary condition. The process to find initial structural overall shape of tension structures produced by initial prestress called Shape Finding or Shape Analysis. One of the most important factor for the design of membrane structures is to search initial smooth surface, because unlike steel or concrete building elements which resist loads in bending, all tension structure forces are carried within the surface by membrane stress or cable tension. To obtain initial surface of fabric membrane element in large deformation analysis, the membrane element is idealized as cable using a technique with Force-density method. and that result is compared with well-known nonlinear numerical method, such as Newton-raphson method and Dynamic relaxation method. The shape resulting from Force-density method has been dealt with as the initial membrane shape and used patterning procedures.

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A Study on Bubbly Lubrication of High-Speed proceeding Bearing Considering Live Surface Tension

  • Chun, S.-M.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.111-112
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    • 2002
  • The influence of aerated oil on a high-speed proceeding bearing is examined by using the classical thermohydrodynamic lubrication theory coupled with analytical models for viscosity and density of air-oil mixture in fluid-film bearing including the live surface tension of aerated oil. Convection to the walls and mixing with supply oil and re-circulating oil are considered. The considered parameters for the study of bubbly lubrication are oil aeration level, air bubble size and shaft speed. The results show that, if the live surface tension is considered, the effect of air bubbles on the bearing load capacity is reduced due to temperature engagement comparing with that under the condition of a constant surface tension.

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The Surface Tension of Solutions of Ammonium Caprylate and Ammonium Caprate (Ammonium Caprylate 와 Ammonium Caprate 溶液의 表面張力)

  • Man Un Han;Chong Man Lee
    • Journal of the Korean Chemical Society
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    • v.7 no.4
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    • pp.277-279
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    • 1963
  • The surface tension of solutions of synthesized ammonium caprylate and ammonium caprate was measured by the ring method. The changes with of surface tension of solution of ammonium caprylate showed evidently that the salt had the critical micelle concentration(c.m.c.) at $30^{\circ}C$. The c.m.c. values of above two salts were determined from the change of surface tension of solution with concentration at various temperatures. The temperature dependence of the c.m.c. and the influence of addition of excess ammonia on the c.m.c. were also investigated.

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The Effect of Temperature, Cooling and Surface Tension on the Fining in Alkali-Alkaline Earth-Silica Glassmelts Containing ZnO

  • Kim, Ki-Dong
    • The Korean Journal of Ceramics
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    • v.4 no.3
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    • pp.176-182
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    • 1998
  • The effects of temperature, cooling surface tension on the fining were studied in alkali-alkaline earth-silica TV screen glassmelts containing ZnO. Sodium antimonate $(Na_2OSb_2O_5)$ was used as a fining agent. Viscosity and surface tension of the melts were determined. On the basis of these properties, fining tests for several batches were performed by "MF" (Melting and Fining) and "PMF" (Profiled melting and Fining) methods. The results of these tests showed an opposite behavior each other with increase in ZnO content. This hehavior has been discussed in terms of two fining processes-growth of bubbles and shrinkage of seeds. shrinkage of seeds.

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Investigation into Deformation of Three-Dimensional Microstructures via Surface Tension of a Rinsing Material During a Developing Process (현상공정에서 표면장력에 의한 극미세 3 차원 구조물의 변형거동 분석 및 저감방안에 관한 연구)

  • Park, Sang-Hu;Yang, Dong-Yol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.4
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    • pp.303-309
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    • 2008
  • Dense and fine polymer patterns often collapse, as they come into contact with each other at their protruding tips. Resist pattern collapse depends on the aspect ratio of patterns and the surface tension of rinsing materials. The pattern collapse is a very serious problem in microfabrication, because it is one of the factors which limit the device dimensions. The reasons for the pattern collapse are known as the surface tension of rinse liquid, centrifugal force and rinse liquid flow produced in the developing process. In this work, we tried to evaluate the pattern collapse of three-dimensional microstructures that were fabricated by two-photon induced photopolymerization, and showed the way how to reduce the deformation of microstructures.

Studies on the Characteristics of EVA Foam by Solvent Treatment (용매 처리에 의한 EVA foam 표면 특성에 관한 연구)

  • Chun, Jae Hwan;Kim, Gu Ni;Hong, Soon Yeong;Yoo, Chong Sun;Oh, Sang Taek
    • Journal of Adhesion and Interface
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    • v.2 no.3
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    • pp.9-15
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    • 2001
  • To estimate the effect of the surface state of the EVA foam on an adhesion, the surface was treated with solvents having different values of a solubility parameter and a surface tension. The morphology and the contact angle were measured by SEM and contact angle tester, respectively. The value of the critical surface tension(${\gamma}_{c,0}$) of the EVA foam calculated by Zismann plot was 27.08 dyne/cm. The surface state and the ${\gamma}_c$ of the EVA foam were changed by solvent treatment. The swelling ratio of EVA foam was influenced by solubility parameter of a solvent, on the other hand the degree of change in the surface state was dependent on a surface tension of a solvent. When a surface tension of solvent. When a surface tension of solvent is lower than ${\gamma}_{c,0}$ of the EVA foam, the wettability of a solvent was good and the surface state was greatly changed. The adhesion strength of EVA foam was greatly improved to above 600% as compared to that of the untreated one. As the ${\gamma}_c$ of EVA was closed to the surface tension of the primer, the good adhesion strength was obtained.

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Surface Active Properties and LCST Behavior of Oligo(propylene oxide-block-ethylene oxide) Allyl Ether Siloxane Surfactants in Aqueous Solution

  • Kim, Doo-Won;Lim, Chul-Hwan;Choi, Jae-Kon;Noh, Si-Tae
    • Bulletin of the Korean Chemical Society
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    • v.25 no.8
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    • pp.1182-1188
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    • 2004
  • Polydisperse oligo(PO-b-EO) allyl ether siloxane surfactants were synthesized by the hydrosilylation reaction of OMTS with Allyl-oligo(PO-b-EO) series. The surface tension of siloxane surfactants increased with increasing the EO chain length while it decreased with increasing the PO ratio. However, the sedimentation time of the aqueous solution showed opposite trend to the surface tension data. Both the surface tension and sedimentation time of the aqueous solution containing inorganic electrolyte gradually decreased as the content of inorganic electrolyte increased because of the surface arrangement of surfactant molecules. However, they increased with an increase of pH values due to the hydrolysis of the siloxane backbone. The $C_p$ values tended to increase with the increase in the EO chain length and decrease of the PO ratio. It seems that intermolecular interaction between PO/EO block copolymer and water affects the variation of transition temperature.

Level Set Advection of Free Fluid Surface Modified by Surface Tension

  • Pineda, Israel;Gwun, Oubong
    • Smart Media Journal
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    • v.4 no.2
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    • pp.9-16
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    • 2015
  • Fluids appear in innumerable phenomena; therefore, it is interesting to reproduce those phenomena by computer graphics techniques. However, this process is not trivial. We work with a fluid simulation that uses Navier-Stokes equations to model the fluid, a semi-Lagrangian approach to solve it and the level set method to track the surface of the fluid. Modified versions of the Navier-Stokes equations for computer graphics allow us to create a wide diversity of effects. In this paper, we propose a technique that allows us to integrate a force inspired by surface tension into the model. We describe which information we need and how to modify the model with this new approach. We end up with a modified simulation that has additional effects that might be suitable for computer graphics purposes. The effects that we are able to recreate are small waves and droplet-like formations close to the surface of the fluid. This model preserves the overall behavior governed by the Navier-Stokes equations.