• Title/Summary/Keyword: characterization.

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Surface Characterization and Morphology in Ar-Plasma-Treated Polypropylene Blend

  • Weon, Jong-Il;Choi, Kil-Yeong
    • Macromolecular Research
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    • v.17 no.11
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    • pp.886-893
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    • 2009

  • Surface modifications using a radio frequency Ar-plasma treatment were performed on a polypropylene (PP) blend used for automotive bumper fascia. The surface characterization and morphology were examined. With increasing aging time, there was an increase in wettability, oxygen containing polar functional groups (i.e., C-O, C=O and O-C=O) due to oxidation, the amount of tale, and bearing depth and roughness on the PP surface, while there was a decrease in the number of hydrocarbon groups (i.e., C-C and C-H). AFM indicated that the Ar-plasma-treatment on a PP blend surface transforms the wholly annular surface into a locally dimpled surface, leading to an improvement in wettability. SEM showed that the PP layer observed in the non-plasma-treated sample was removed after the Ar-plasma treatment and the rubber particles were exposed to the surface. The observed surface characterization and morphologies are responsible for the improved wettability and interfacial adhesion between the PP blend substrate and bumper coating layers.

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A six-point characterization of Hilbert spaces

  • Mok, Jin-Sik
    • Communications of the Korean Mathematical Society
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    • v.12 no.4
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    • pp.905-909
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    • 1997

  • A characterization of Hilbert spaces is given in terms of four boundary points and two interior points of the unit sphere.

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A metric characterization of Hilbert spaces

  • Mok, Jin-Sik
    • Bulletin of the Korean Mathematical Society
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    • v.33 no.1
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    • pp.35-38
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    • 1996

  • The aim of this paper is to present a characterization of Hilbert spaces in terms of the lengths of four sides and two diagonals of a parallelogram.

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