• Title/Summary/Keyword: Immiscible

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SYMMERIC CURRENTS OF A TWO-LAYER FLUID WITH FREE SURFACE OVER AN ELLIPTIC OBSTRUCTION

  • Park, J.W.
    • Journal of the Korean Mathematical Society
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    • v.34 no.1
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    • pp.119-133
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    • 1997
  • This paper concerns the symmetric wave solutions between two immiscible, inviscid, and incompressible fluids of different but constant densities in the presence of small elliptic obstruction of compact support at the rigid bottom when the effect of gravity is considered (Fig. 1).

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Morphological Effect of Dispersed Phase on Gas Separation Properties through Heterophase Polymer Membrane: Theoretical and Experimental Approaches.

  • Park, Cheolmin;Jo, Won-Ho;Kang, Yong-Soo
    • Proceedings of the Membrane Society of Korea Conference
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    • 1996.04a
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    • pp.55-56
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    • 1996
  • Heterophase polymer system has been attractive for a potential applicability to gas separation membrane material. It has been known that there is a trade-off between gas permeability and its selectivity in common polymers. Therefore, the heterophase polymer can be an alternative for a gas separation membrane material because its transport properties can be readily controlled by blending of two different polymers. The transport properties of immiscible polymer blends strongly depend upon the intrinsic transport properties of corresponding polymers. Another important factor to determine the transport properties is their morphology: volume fraction, size and shape of dispersed phase. Although the effect of the volume fraction of the dispersed phase on the transport properties has been widely investigated, the size and shape effects have been paid attention very much. In an immiscible polymer blend of two polymers, its morphology is primarily controlled by its volume fraction of dispersed phase. Therefore, the effect of the size of the dispersed phase can be hardly seen. Therefore, a block copolymer has been commonly employed to control their morphology when each block is miscible with one or the other phase. In this work, gas transport properties will be measured by varying the morphology of the heterophase polymer membrane. The transport properties will be interpreted in terms of their morphology. The effect of the volume fraction of the PI phase and, in particular, its size effect will be investigated experimentally and theoretically.

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Recent Emulsion Technology in Cosmetics (화장품용 유화 제조기술 최근동향)

  • Hwang, So-Ra;Nam, Jin-Oh;Lee, Byung-Jin;Song, Woo-Ho;Lee, Chang-Soo
    • KSBB Journal
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    • v.27 no.4
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    • pp.207-214
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    • 2012
  • Emulsions are mixture of immiscible liquids in which one is dispersed in all over the other. They have been applied to many applications including cosmetics, foods, drug delivery system (DDS), fine chemicals, and chemical separations. Especially, emulsion technology is one of the most useful technique to formulate cosmetics such as eye cream, foundation, and foam cleansing. In general, the emulsions can be generated by mechanical agitation of two immiscible fluids. However, the emulsions obtained by conventional method have limited in stability, monodispersity, and complicate process. We describe here preparation techniques of representative cosmetic emulsions such as liposome, liquid crystal emulsion, nanoemulsion, multiple emulsion, and pickering emulsion. Furthermore, various factors which can control the physical properties of each cosmetic emulsions are briefly discussed.

Study of Synthesis and Magnetic Properties of Ni and Ni-Cu Nano Metal Powders Prepared by the Pulsed Wire Evaporation(PWE) Method (전기폭발법에 의한 Ni 및 Ni-Cu 나노 금속 분말의 제조와 자기적 특성연구)

  • 박중학;엄영랑;김경호;김흥희;이창규
    • Journal of Powder Materials
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    • v.10 no.2
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    • pp.83-88
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    • 2003
  • Nanocrystalline materials of Ni and Ni-Cu alloy have been synthesized by the pulsed wire evaporation (PWE) method and these abnormal magnetic properties in the magnetic ordered state have been characterized using both VSM and SQUID in the range of high and low magnetic fields. Ni and Ni-Cu particles with an average size of 20 to 80 nm were found to influence magnetic hysterisis behavior and the results of powder neutron diffraction patterns and saturation magnetization curves are shown to indicate the absence of the NiO phase. The shifted hysterisis loop and irreversibility of the magnetization curve in the high field region were observed in the magnetic-ordered state of both Ni and Ni-Cu. The virgin magnetization curve for Ni slightly spillover on the limited hysterisis loop ($\pm$20kOe). This irreversibility in the high field of 50 kOe can be explained by non-col-linear behavior and the existence of the metastable states of the magnetization at the surface layer (or core) of the particle in the applied magnetic field. Immiscible alloy of Cu-Ni was also found to show irreversibility having two different magnetic phases.