• Title/Summary/Keyword: plastics

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Overview of Polyamide Resins and Composites : A Review

  • Lee, Jong-Young;Kim, Kwang-Jea
    • Elastomers and Composites
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    • v.51 no.4
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    • pp.317-341
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    • 2016
  • Polyamide (PA) is one of five engineering plastic materials which has good mechanical properties and competitive price compared to other engineering plastics and it has various applications including in the areas of automotives, electronics and aerospace industry. Even though PA market grows fast compared to other engineering plastics, it has few organized literatures regarding researches and applications. In this paper, we review overall background, characteristics, formulation, current market trends and technology development of PA resins and their composites.

Production and Application of Polyhydroxyalkanoates (Polyhydroxyalkanoates의 생산 및 응용)

  • 이상엽;이영최종일
    • KSBB Journal
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    • v.10 no.4
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    • pp.406-420
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    • 1995
  • Polyhydroxyalkanoates[PHAs] are the polyester of hydroxyalkanoates(HAs) synthesized by numerous bacteria as an intracellular carbon and energy storage compound and accumulated as granules in the cytoplasm of the cells under unbalanced growth condition in the presence of excess carbon source. Even though PHAs have been recognized as good candidates for biodegradable plastics, their high price compared with conventional plastics has limited their use in a wide mange of applications. To reduce the high production cost of PHAs, many group of scientists have devoted much efforts to improve productivity by employing various microorganisms and by developing efficient culture techniques. The strategies of producing PHAs to a high concentration with high productivity and their potential applications are reviewed.

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Analysis on piotical changes in Hanger Design: From 1850 to 2003 (시대적 흐름에 따른 옷걸이 변화에 관한 연구 -1850년경부터 2003년까지 -)

  • 조숙경
    • Journal of the Korea Furniture Society
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    • v.14 no.2
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    • pp.87-96
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    • 2003
  • This study explores aesthetics and materials used in domestic and international hanger designs from 1850 to 2003. At the second half of the nineteenth century, most hangers were handmade and made of wood and metal. At the first half of the twentieth century, such diverse materials as paper, plastics, and leather began to use other than such typical materials as wood and metal at the previous decades. However, from the second half of the twentieth century the use of different types of plastics led to artistic abnormal shapes within typical triangular types. Moreover, this study also examines hangers by its functions: primary, portable, and multi-functional types.

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A Pilot Study on Emissions of Air Pollutants Produced from Incineration of Some Municipal Solid Wastes

  • Kim, Haen-Gah;Lee, Byeong-Kyu;Cho, Jung-Bum
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.E2
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    • pp.49-56
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    • 2006
  • This pilot study focuses on emissions characterization of air pollutants produced from incineration of some municipal solid wastes (MSWs). The MSWs incinerated by an electric furnace maintained up to $600^{\circ}C$ included food, paper, and plastic wastes. The pollutants analyzed in this study included concentrations of volatile organic compounds (VOCs), bottom ash contents, and heavy metals extracted from the bottom ash of each waste. The VOCs identified were classified based on their chemical structure. The total emissions of VOCs produced from incineration of the papers were identified as the highest followed by those from the plastics and the food wastes. Aliphatic alkenes were major VOC compounds produced from incineration of plastic or food wastes, while furans were major VOCs produced from incineration of papers. The second major VOCs produced from incineration of food, plastics, and papers were aromatics. In particular, hazardous air pollutants such as benzene were produced with considerable amount of emission concentration. The bottom ash contents of papers were usually much higher than those of food or plastic wastes. The bottom ash contents produced from incineration of food and plastics were much lower than those of other MSWs. In analysis of heavy metals extracted by an ultrasonic method from the bottom ashes of the papers, high concentrations of heavy metals were identified from incineration of newspapers and box (cardboard). In addition, it was identified that the general public might be exposed to considerable amounts of lead concentrations during incineration processes and uses of paper cup and from ashes.