• Title/Summary/Keyword: flowerlike

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A Novel Flowerlike Nanostructured CeO2 for Sustainable Energies

  • Li, Hong;Chen, Liquan
    • Journal of the Korean Ceramic Society
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    • v.47 no.1
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    • pp.66-70
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    • 2010
  • This article presents a brief review of our recent studies on flowerlike nanostructured $CeO_2$ materials. These materials are monodispersed microspheres with peony appearance, open mesoporous structure, large specific surface area and nano-crystalline feature. The applications of this type of novel material to SOFC, ethanol steam reforming and CO oxidation are introduced.

Change of Anti-reflective Optical Property by Nano-structural Control of Alumina Layer through Hydro-thermal Process (수열합성 공정을 통한 알루미나 코팅층의 나노구조 조절에 의한 반사방지 특성의 변화)

  • Lee, Yun-Yi;Son, Dae-Hee;Lee, Seung-Ho;Lee, Gun-Dae;Hong, Seong-Soo;Park, Seong-Soo
    • Applied Chemistry for Engineering
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    • v.21 no.5
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    • pp.564-569
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    • 2010
  • Highly anti-reflective optical property has been focussed in the field of thin film and display because of increasing demands to the high transparency and clearness of optical component. In this study, to obtain anti-reflective property, the formation of aluminium oxide with nanoscaled flowerlike frame structure was introduced as oxide material monolayer on the substrate by hydrothermal synthesis through sol-gel method. The properties of coating layer were measured by the means of UV-Vis spectroscopy, FT-IR spectroscopy, XRD, and FE-SEM. The morphology of coating layer in alumina-sol coated samples was controlled by hydrothermal temperature and time with aid of ultrasound. It was found that high transparency and anti-reflective optical properties were obtained the formation of flowerlike nanoframe structure.

Effect of associating polymer on the dispersion stability and rheology of suspensions

  • Otsubo, Yasufumi;Horigome, Misao
    • Korea-Australia Rheology Journal
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    • v.15 no.1
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    • pp.27-33
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    • 2003
  • Associating polymers are hydrophilic long-chain molecules to which a small amount of hydrophobic groups (hydrophobes) is incorporated. In aqueous solution, the association interactions result in the formation of three-dimensional network through flowerlike micelles at high concentrations. In colloidal suspensions, the associating polymers act as flocculated by bridging mechanism. The rheological properties of suspensions flocculated by associating polymers end-capped with hydrophobes are studied in relation to the bridging conformation. At low polymer concentrations, the polymer chains effectively form bridges between particles by multichain association. The suspensions are highly flocculated and show typical viscoelastic responses. When the polymer concentration is increased above the absorbance at saturation, the excess polymer chains remaining in the solution phase build up three-dimensional network by associating interactions. Since the presence of particles does not significantly influence the network structures in the medium, the relative viscosity, which gives a measure of the degree of flocculation is decreased with increasing polymer concentration. The bridging conformation and flocculation level vary strongly depending on the polymer concentrations.

The Interpreggtation of the Indian Stupa as Origin of Korean Pagoda (탑의 원조 인도 스투파의 형태 해석 - 인도 전역의 현장 답사를 바탕으로 -)

  • Lee, Hee-Bong
    • Journal of architectural history
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    • v.18 no.6
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    • pp.103-126
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    • 2009
  • This study aims to discover historical trends and change of form of all stupas in India with observation of field study that is as direct as possible, by classifying, analyzing, and synthesizing the stupas. Study of Indian stupa in Korea has a number of shortcomings since only introductory partial approach has been made in order to seek the origin of Korean pagoda. This study also aims to correct errors of stupa terminology in Chinese character committed by misinterpretation of Hindi language which was established by precedent Japanese scholars several decades ago. Piled-up stupas were totally destroyed by pagans, therefore their remains tell us only of structure, material, sizeand disposition. However remains of carved stone at torana and drum give us clues as to the original form of stupa and worshipping activity, as well as change to a more luxurious form. Many rock cave stupas of India show us both simple forms matching the ascetic age of early Buddhism and luxurious changes in Mahayanan era introducing us to statues of Buddha. Indians recovered the spheric form of 'anda,' a Hindi term meaning cosmic egg, from the hemispheric form of the piled-up stupa. Therefore we might discard the erratic term of 'bokbal', which means an upset vessel. Railings and parasols became main factors of stupa design. Carved railings around stupa became a sign of divinity. Serious worshipping activity made drums long or high and created multi-embossed stripes. Bases of circular drums of some cave stupas changed their shapes to rectangular or octagonal. Single parasols became multiparasols of affluent flowerlike curved stems on carved stupa. Multistoried, elongated and high parasols of Gandhara stupas are closely related to such factors as diverse changes of form in Indian subcontinent. Four-sided torana gate and ayaka column of the circular form of original stupas suggest the rectangular form of subsequent East Asian pagoda, and higher and wider base of Indian stupas became the origin of East Asian rectangular pagoda.

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