• Title/Summary/Keyword: atmospheres

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Properties of Photoluminescence and Growth of CdIn2Te4 Single Crystal by Bridgeman method (Bridgeman법에 의한 CdIn2Te4 단결정 성장과 광발광 특성)

  • Moon, Jong-Dae
    • Journal of Sensor Science and Technology
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    • v.12 no.6
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    • pp.273-281
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    • 2003
  • A stoichiometric mixture for $CdIn_2Te_4$ single crystal was prepared from horizontal electric furnace. The $CdIn_2Te_4$ single crystal was grown in the three-stage vertical electric furnace by using Bridgeman method. The quality of the grown crystal has been investigated by the x-ray diffraction and the photoluminescence measurements. The (001) growth plane of oriented $CdIn_2Te_4$ single crystal was confirmed from back-reflection Laue patterns. The carrier density and mobility of $CdIn_2Te_4$ single crystal measured with Hall effect by van der Pauw method are $8.61{\times}10^{16}\;cm^{-3}$ and $242\;cm^2/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $CdIn_2Te_4$ single crystal obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=1.4750\;eV-(7.69{\times}10^{-3}\;eV)T^2/(T+2147)$. After the as-grown $CdIn_2Te_4$ single crystal was annealed in Cd-, In-, and Te-atmospheres, the origin of point defects of $CdIn_2Te_4$ single crystal has been investigated by the photoluminescence(PL) at 10 K. The native defects of $V_{Te}$, $Cd_{int}$, and $V_{Cd}$, $Te_{int}$ obtained by PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the Cd-atmosphere converted $CdIn_2Te_4$ single crystal to an optical n-type. Also, we confirmed that In in $CdIn_2Te_4$ did not form the native defects because In in $CdIn_2Te_4$ single crystal existed in the form of stable bonds.

The Understanding for Acceptance of Kitsch and Vernacular concepts in Product Design (키치와 버내큘러 개념의 제품디자인 수용을 위한 이해)

  • Ryu, Seung-Ho;Moon, Charn
    • Archives of design research
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    • v.18 no.3 s.61
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    • pp.199-208
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    • 2005
  • This study analysis if the concepts of kitsch and vernacular remains as cultural elements for product design. Because their function and aesthetic value have vivid possibilities for general product design fields. For the purpose, this study limits its range within post modernism, kitsch, and vernacular, and analyzes their relationships. Against functionalism, post modernism had cultural pluralisms to approach into popular styles, and some of them was amusing design. That post modernism designs stimulated human beings' emotion by decorations or some symbolic forms from specific objects is similar to the symbolism, regionalism, or pluralism of kitsch or vernacular. Kitsch is a free style that is not limited in any specific trends. It is a Meta culture that has influenced into various fields including design, so kitsch does not have a parallel position with a product or design. In product design, kitsch is the behavior and result of imitating existing objects' images. It could have amusement according to which objects are imitated. So if human beings feel amusement by kitsch, it could be same as the direction of post modernism. Kitsch is determined by design atmospheres. They cannot be specified abjectly, and can be different according to people. With symbolism and regionalism, kitsch and vernacular appeared according to people's needs. While kitsch is consumer's tastes-oriented, vernacular is cultural tradition-oriented. Kitsch has symbolism that specifies products' functions or design concepts, and it is a communication method between human being and products. Because vernacular is province-oriented, it has a lot of styles according to regional living environments and cultural differences. So vernacular design reflects continued traditional lifestyles. By restorative memory, regionalism, cultural pluralism, amusement, and symbolism, kitsch and vernacular could be understood the sub or parallel concepts of post modernism. They might be easily miss-understood mixed concepts that have western and national characters. But in kitsch and vernacular concept, modernizing pas by using the pluralism of post modernism should be considered positive. So, the range of the further study is also supposed to be focused on more widened fields to, to establish cultural identification in design.

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Quality Changes of 'Yeobong' Strawberry with CA Storage Conditions (CA저장조건에 따른 '여봉' 딸기의 품질변화)

  • Kim, Ji-Gang;Hong, Seong-Sik;Jeong, Seok-Tae;Kim, Young-Bae;Jang, Hyun-Sae
    • Korean Journal of Food Science and Technology
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    • v.30 no.4
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    • pp.871-876
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    • 1998
  • 'Yeobong' strawberries were stored at $2^{\circ}C$ under controlled atmosphere (CA) containing the combinations of $O_2{\;}(3.8%)$ and $CO_2{\;}(10,{\;}15,{\;}20%)$ and air as control. Atmospheres of $3%{\;}O_2+15%{\;}CO_2$ and $8%{\;}O_2+15%{\;}CO_2$ reduced respiration and ethylene production rates. Fruits kept under CA conditions of 10% and 15% $CO_2$ were harder than those stored under 20% $CO_2$ and air. The CA conditions of 10% or 15% $CO_2$ maintained approximately 80% of vitamin C for 24 days. Redness were increased and then decreased, but the changing trends were not clear among the storage conditions. Anthocyanin contents in $3%{\;}O_2+15%{\;}CO_2$ and $8%{\;}O_2+15%{\;}CO_2$ were slightly increased for 16 days and then decreased thereafter, while anthocyanin content in air was rapidly increased for 8 days. After 16 days of storage, off-flavor were perceived in all CA storage. And strawberries stored in 20% $CO_2$ conditions were unacceptable after 20 days. The 20% $CO_2$ significantly affected off-flavor of strawberries, but there was no significant difference between 10% $CO_2$ and 15% $CO_2$ conditions. Ethanol which is in relation to off-flavor was higher with elevated $CO_2$ levels. Although CA conditions under $3%{\;}O_2+15%{\;}CO_2$ was effective in delaying the quality changes, there was high ethanol content compared to $8%{\;}O_2+15%{\;}CO_2$ condition. Strawberry kept under $8%{\;}O_2+15%{\;}CO_2$ was maintained the shelf-life for 24 days and the condition prolonged more $4{\sim}8$ days and 12 days than the other CA conditions and air, resectively.

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Densification Behavior and Magnetic Properties of Fe-2%Ni Sintered Compact Fabricated by Metal Injection Molding (사출성형법에 의해 제작된 Fe-2%Ni연자성 소결체의 소결 및 자기적 특성)

  • Lim, Tae-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.278-283
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    • 2019
  • 3 kinds of fine powder, Fe-2%Ni alloy powder(N Ltd.) and Fe+2%Ni mixed powder(B Ltd. and S Ltd.), were fabricated into sintered compacts of bending strength specimens and ring type specimens by metal injection molding, debinding and controlling sintering conditions (reduction and sintering atmospheres, sintering temperature, sintering time and cooling rates). Density and magnetic properties of the sintered compacts were evaluated with the following conclusions. (1) When each compact was hold at 1123K for 3.6ks in H2 and sintered at 1623K for 14.4ks in Ar, the density of N, B and S Ltd.'s sintered compacts were measured as 96, 99 and 99%, and oxygen/carbon contents were measured as 0.0041%O/0.0006%C, 0.0027%O/0.0022%C, and 0.160%O/0.0026%C, respectively. (2) Magnetic characteristics of B Ltd. compact in Ar with the best results showed $B_{25}=14.3KG$, $B_r=7.75KG$, and $H_c=2.1Oe$, but not enough as those made by melting process. (3) Magnetic properties of B Ltd. compact which were sintered at 1673K for 14.4ks in Ar gas, and cooled at $0.83Ks^{-1}$ to 1123K and then cooled at $0.083Ks^{-1}$ down to room temperature were measured as $B_{25}=14.8KG$, $B_r=8.3KG$, and $H_c=1.3Oe$, almost similar to those made by melting process. Objected soft magnetic materials properties were obtained through sintering process by controlling sintering conditions (reduction condition, sintering atmosphere, sintering temperature and sintering time) and cooling rates.