• Title/Summary/Keyword: Liquid formability

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Liquid Silicon Infiltrated SiCf/SiC Composites with Various Types of SiC Fiber (다양한 SiC 섬유를 적용한 실리콘 용융 침투 공정 SiCf/SiC 복합재료의 제조 및 특성 변화 연구)

  • Song, Jong Seob;Kim, Seyoung;Baik, Kyeong Ho;Woo, Sangkuk;Kim, Soo-hyun
    • Composites Research
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    • v.30 no.2
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    • pp.77-83
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    • 2017
  • Liquid silicon infiltration, which is one of the methods of producing fiber reinforced ceramic composites, has several advantages such as low fabrication cost and good shape formability. In order to confirm LSI process feasibility of SiC fiber, $SiC_f/SiC$ composites were fabricated using three types of SiC fibers (Tyranno SA, LoxM, Tyranno S) which have different crystallinity and oxygen content. Composites that were fabricated with LSI process were well densified by less than 2% of porosity, but showed an obvious difference in 3-point bending strength according to crystallinity and oxygen content. When composites in LSI process was exposed to a high temperature, crystallization and micro structural changes were occurred in amorphous SiOC phase in SiC fiber. Fiber shrinkage also observed during LSI process that caused from reaction in fiber and between fiber and matrix. These were confirmed with changes of process temperature by SEM, XRD and TEM analysis.

A study on the expression types and internal meanings of ecology images appeared in modern digital fashion (현대 디지털 패션에 나타난 생태적 이미지의 표현유형과 내적 의미)

  • Kang, Junho;Kwon, Giyoung
    • The Research Journal of the Costume Culture
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    • v.29 no.3
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    • pp.422-436
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    • 2021
  • The fashion industry analyzes the value of its essence with ecological design and is expressed as an innovative sculpture using digital technology. Accordingly, this study explores ecological images and digital technologies, categorizes types and derives their meanings through analysis of ecological images shown in modern digital fashion. A literature survey was conducted on ecological images and digital technology as a theoretical background. To analyze the expression type and internal meanings of ecological images, designs with ecological formability were selected and analyzed from related journals, books, and internet sites. The finding are as follows: The expression type was first identified as organic curved garment silhouettes of a non-material liquid with digital retouching. Second, ecological fashion design includes structural shape that applies the silhouette of an organism and patterning of the ecosystem. Third, ecosystems consist of interactions between components of an ecosystem that appear in the interactive type. Accordingly, the internal meanings of ecological images in modern digital fashion are: first, digital fashion can encircle the inherent concepts of nature as organic collections of individuals; second, digital ecological images emphasize a sense of community with coexistence and harmony, playing a complementary role; and finally, the images express perceptual features by providing people with transcendent experiences. This study is significant as it analyzes new formative features based on ecological systems in the digital fashion environment, establishes an aesthetic system through internal meanings, and enhances awareness of human-natural relationships.

Effect of Solution Temperature on the Cavitation Degradation Properties of Epoxy Coatings for Seawater Piping

  • Jeon, J.M.;Yoo, Y.R.;Jeong, M.J.;Kim, Y.C.;Kim, Y.S.
    • Corrosion Science and Technology
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    • v.20 no.6
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    • pp.335-346
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    • 2021
  • Since epoxy resin coating shows excellent properties in formability, adhesion, and corrosion resistance, they have been extensively used in many industries. However, various types of damages in the epoxy coated tube within a relative short time have been reported due to cavitation erosion, liquid impingement, variation of temperature and pressure. Nevertheless, there has been little research on the effect of temperature on the cavitation degradation of epoxy coatings. Therefore, this work used an ultrasonic cavitation tester to focus on the effect of solution temperature on the cavitation properties of 3 kinds of epoxy coatings in 3.5% NaCl. The cavitation properties were discussed basis on the material properties and environmental aspects. As the solution temperature increased, even though with large fluctuation, the cavitation degradation rates of A and B coatings were reduced rapidly, but the rate of C coating was decreased gradually. In addition to the cushioning effect, the reason that the cavitation degradation rate reduced with solution temperature was partly related to the brittle fracture and water absorptivity of the epoxy coatings, and the water density, but was little related to the shape and composition of the compound in the coatings or the phase transition of the epoxy coating.