• 제목/요약/키워드: D. Coating

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The Effects of Pattern Coatings on the Solidification of Pure Aluminum Castings and the Thermal Behavior of Molds in FMC Processes (FMC법에서 모형 도형제가 순알루미늄 주물의 응고와 주형의 열적거동에 미치는 영향)

  • Cho, N.D.;Kim, Y.N.
    • Journal of Korea Foundry Society
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    • v.7 no.2
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    • pp.122-132
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    • 1987
  • Full mold casting process is a new technique offering numerous advantages and promising possibilities. The present study is aimed to bring out the results of experiments carried out to study the effect of pattern coatings on the solidification of 99.5% pure aluminum plate-shaped castings in the various sand molds and the thermal behavior of the molds. The results of the investigation indicate that (i) with increase in pattern coating thickness, the relative chilling power decreases gradually for silica and increases for zircon coating, and (ii) the application of a pattern coating significantly reduces the maximum interface temperature by the mold which is more pronounced in the case of thinner mold wall. The investigation also indicates that Chvorinov's rule is not found to be valid for the casting in the full mold, with or without pattern coating. Therefore in full mold process, the pattern coating thickness will be a very important parameter in the study of thermal behavior.

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I-V Modeling Based on Artificial Neural Network in Anti-Reflective Coated Solar Cells (반사방지막 태양전지의 I-V특성에 대한 인공신경망 모델링)

  • Hong, DaIn;Lee, Jonghwan
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.3
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    • pp.130-134
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    • 2022
  • An anti-reflective coating is used to improve the performance of the solar cell. The anti-reflective coating changes the value of the short-circuit current about the thickness. However, the current-voltage characteristics about the anti-reflective coating are difficult to calculate without simulation tool. In this paper, a modeling technique to determine the short-circuit current value and the current-voltage characteristics in accordance with the thickness is proposed. In addition, artificial neural network is used to predict the short-circuit current with the dependence of temperature and thickness. Simulation results incorporating the artificial neural network model are obtained using MATLAB/Simulink and show the current-voltage characteristic according to the thickness of the anti-reflective coating.

A Study on the Electrical Conductivity and Electromagnetic Pulse Shielding Characteristics of Metal Sprayed Coating (금속 용사 피막의 전기전도도 및 전자파 차폐 특성에 관한 연구)

  • Jang, Jong-Min;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.8-9
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    • 2020
  • In this study, the electrical conductivity and shielding effect were evaluated according to the type of metal and the thickness of Metal sprayed coating. The metals used for the test are Cu, Cu-Ni and Cu-Zn, and the thicknesses were 100, 200, 500 um. Each metal sprayed coating was evaluated for electrical conductivity and electromagnetic shielding effect. When the thickness was 200 ㎛ or more, shielding effect 80 dB or more was satisfied at 1 GHz. However, in the case of Cu-Ni, there is little electrical conductivity at a thickness of 100 um or less due to the generated voids, and electromagnetic wave shielding performance cannot be expected. Therefore, To ensure electromagnetic shielding effect of structures, it is considered that the minimum thickness of metal spraying coating should be 200 um.

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Microenvironmental Optimizaton of Immobilized Invertase for Methyl- $\beta$ -D-Fructofuranoside Synthesis (Methyl- $\beta$ -D-Fructofuranoside 합성을 위한 고정화 전화당 효소의 미소환경 최적화)

  • 허주형;안형환
    • Journal of the Korea Safety Management & Science
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    • v.1 no.1
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    • pp.259-272
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    • 1999
  • In order to enhance the selectivity, productivity and yield of methyl fructoside, which was synthesized by enzymatic glycosylation of sucrose and methanol solution, controlling of surface property of solid support using different immobilization procedures optimized microenvironment of immobilized invertase. Silanization and polyethylene imine coating methods were adopted to give a hydrophobic and hydrophilic environment of immobilized invertase. As a result, polyethyleneimine coating method gave higher loading of enzyme, effective activity, and relative activity than silanization method, because it brought on increasing the functional density of amino group and enhancing the conservation of activity by regulating of hydrophilicity. And then, hydrophilic environment was possible to restraint the assessing of methyl fructoside molecule, which was more hydrophobic than sucrose, fructose, and glucose molecule in the reaction mixture, into .the active site of immobilizedinvertase. Consequently, hydrophilic microenvironment of immobilized invertase by polyethyleneimine coating obtained higher yield and productivity with increasing conversion than silanized and native invertase. Thus, this procedure optimized the microenvironment of immobilized invertase suitable for the enzymatic synthesis of methyl fructoside.

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