• Title/Summary/Keyword: Functional Material

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Thin Oxide Functional Films by Metal Alkoxide Method

  • Natalya, Korobova
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.9-16
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    • 2000
  • A survey over the role of sol-gel processing and metal alkoxides in the thin film preparation is given. The basic chemistry of the sol-gel process is complex due to the different reactivities of the network forming and the wide variety of reaction parameters. Despite the important progress in the investigations of the mechanisms of thin film formation, a direct relation of reaction parameters to functional oxide properties is still very difficult.

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On Functional Equations (함수방정식의 유래)

  • Ree, Sangwook;Koh, Youngmee
    • Journal for History of Mathematics
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    • v.34 no.5
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    • pp.153-164
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    • 2021
  • A functional equation is an equation which is satisfied by a function. Some elementary functional equations can be manipulated with elementary algebraic operations and functional composition only. However to solve such functional equations, somewhat critical and creative thinking ability is required, so that it is educationally worth while teaching functional equations. In this paper, we look at the origin of functional equations, and their characteristics and educational meaning and effects. We carefully suggest the use of the functional equations as a material for school mathematics education.

Preparation and Analysis of High Functional Silicone Hydrogel Lens Containing Metal Oxide Nanoparticles by Photopolymerizaion

  • Heo, Ji-Won;Sung, A-Young
    • Korean Journal of Materials Research
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    • v.32 no.4
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    • pp.193-199
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    • 2022
  • In this study, lenses are fabricated using various nanomaterials as additives to a silicone polymer made with an optimum mixing ratio and short polymerization time. In addition, PVP is added at a ratio of 1 % to investigate the physical properties according to the degree of dispersion, and the compatibility with hydrophobic silicone and the possibility of application as a functional lens material are confirmed. The main materials are SIU as a silicone monomer, DMA, a hydrophilic copolymer, EGDMA as a crosslinking agent, and 2H2M as a photoinitiator. Holmium (III) oxide, Europium (III) oxide, aluminum oxide, and PVP are used. When Holmium (III) oxide and Europium (III) oxide are added based on the Ref sample, the characteristics of the lens tend to be similar overall, and the aluminum oxide shows a tendency slightly different from the previous two oxides. This material can be used as a silicone lens material with various nano oxides and polyvinylpyrrolidone (PVP) acting as a dispersant.

A study on the multi-functional fashion design - focused on the climatic change and environment consciousness- (다기능 패션디자인에 관한 연구 - 기후변화 및 환경의식을 중심으로 -)

  • Lee, Hyun-Young;Park, Hye-Won
    • Journal of Fashion Business
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    • v.13 no.2
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    • pp.123-135
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    • 2009
  • To cope with the threats posed by climate change actively, this study tries to examine multi-functional fashion design with the moral awareness of environment, which could be a direct cause of climate change. Literature and patents on multi-functional fashion design following climate change at home and abroad are examined to find the trend of multi-functional fashion designs. And fashion design that can protect human body to cope with climate change is analyzed. This study found that first, it is necessary to recognize the environment problems in the design process so that material is used to the minimum to minimize pollution and enable welfare and continuation of human society; second, environmentally friendly production and rational consumption such as manual production without waste of energy and material need to be favored to minimize the destruction of environment; third, to cope with environment and climate changes, design that allows an item to have diverse functions is needed so that it can have varied lengths, widths, and thicknesses, and it can be put on and taken off.

Improved Cycle Performance of Sulfur-Doped LiFePO4 Material at High Temperatures

  • Lee, Seung-Byung;Cho, Seung-Hyun;Aravindan, Vanchiappan;Kim, Hyun-Soo;Lee, Yun-Sung
    • Bulletin of the Korean Chemical Society
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    • v.30 no.10
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    • pp.2223-2226
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    • 2009
  • Pristine and sulfur-doped (LiFe$PO_{3.98}S_{0.03}$) lithium iron phosphates were synthesized by a sol-gel method. The XRD pattern of the prepared materials suggested an orthorhombic structure with a Pnma space group and an absence of impurities. The Li/LiFe$PO_4$ or LiFe$PO_{3.98}S_{0.03}$ cells were employed for cycling studies at various temperatures (25, 50 and $60\;{^{\circ}C}$). In all cases, the Li/LiFe$PO_{3.98}S_{0.03}$ cell showed an improved performance with a stable discharge behavior of ~155 mA$hg^{-1}$. Nevertheless, pristine LiFeP$O_4$ cells presented poor discharge behavior at elevated temperatures, especially $60\;{^{\circ}C}$.

Development of Functional Milk and Dairy Products by Nanotechnology (나노 기술을 이용한 기능성 우유 및 유제품의 개발 연구)

  • Gwak, Hae-Su
    • Journal of Dairy Science and Biotechnology
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    • v.23 no.1
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    • pp.27-37
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    • 2005
  • The development of functional foods started booming from several years ago in the world. The size of functional materials are in the range of micrometer level. This size can be much smaller into nanometer level to be more effective. We face some problems from the materials, such as flavor, taste, color, viscosity, etc. in functional materials. The problems can be solved by micro / nanoencapsulation technique. This paper showed some results of the research related on the technique for functional milks and dairy products. The nono / microcapsules are the form of liquid instead of solid. Coating materials used were fatty acid esters, and core materials were lactase, iron, ascorbic acid. isoflavone, and chitooligosaccharide. The ranges of capsules are from 100 nm to 200 ${\mu}$m. The sample milks added nano/microcapsules were homogeneous and prevented the defects of core materials. It was observed that nano / microcapsules in milk and dairy products were effective as functional material without defaults. It was indicated that targeted functional foods can be developed further in various foods by nanotechnology.

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