• Title/Summary/Keyword: expanded polystyrene

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Freshness Extension of Squash (Cucurbita moschata) Packed with Expanded Polystyrene Foam Box (Expanded Polystyrene Foam Box로 포장한 애호박의 신선도 유지 효과)

  • 박형우;박종대;이명훈
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.29 no.1
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    • pp.76-79
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    • 2000
  • The effects of packaging conditions on freshness extension of squash (Cucurbita moscata) were investigated during 7-day storage at 2$0^{\circ}C$. Weight loss of squash packed with corrugated paperboard box (control) was 5.5%, and those of LDPE (low density polyethylene, Ф0.02 mm), LDPE (Ф0.04mm) film and EPS (expanded polystyrene) box were 0.9%, 0.8%, and 1.1%, respectively. Firmness of EPS was 11% higher than that of control, chlorophill content of squash packed with EPS box was 18.9% higher, and total ascorbic acid content of squash packed with EPS box was 29.4% higher than that of control. Quality of packed squash was not different between EPS packages and LDPE packages. Decay of control was 1~2 pieces per box, but was not found in the LDPE, EPS box. Preferences in overall appearences of LDPE, EPS box was better than those of control.

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Case Studies of EPS Failure and Quality Control by Site Monitoring (EPS 공법의 파괴사례 및 품질관리 개선방안)

  • 김호비;주태성;류기정;한태곤;김태경;정종권
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.401-408
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    • 2003
  • EPS(Expanded Polystyrene) has been used in a variety of applications as a solution of difficult soil conditions encountered in construction activities. Although there has been significant worldwide growth in the use of EPS as a lightweight fill material, it has a few failure cases before and after the construction. This paper described the observed failures of EPS structures up In date around the world. Also, method of quality control was proposed for site monitoring.

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Setting Behavior of Polystyrene Mortars with Elapsed Curing Time (폴리스티렌 모르타르의 양생재령에 따른 경화거동)

  • Choi Nak-Woon;Kim Han-Sang
    • Journal of the Korea Concrete Institute
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    • v.16 no.1 s.79
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    • pp.54-60
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    • 2004
  • This study deals with the setting behavior of polystyrene mortars using waste expanded polystyrene(EPS) solution-based binders. The binders for polystyrene mortars are made by mixing crosslinking agent with EPS solutions prepared by dissolving EPS in styrene. Polystyrene mortars are prepared with various EPS concentrations of EPS solutions and crosslinking agent contents, subjected to a dry curing, and tested for working life, peak exotherm temperature and 10h-length change. From the test results, He working lives of polystyrene mortars are shortened with raising EPS concentration of EPS solution and crosslinking agent content. Low-shrinkage or non-shrinkage polystyrene mortars could be obtained by adjusting EPS concentration of EPS solution and crosslinking agent content.

Setting Properties of Polystyrene Mortars (폴리스티렌 모르타르의 경화특성)

  • 최낙운;오하마요시히코;소양섭;김완영
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.793-798
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    • 2003
  • The purpose of this study is to investigate the setting properties of polystyrene mortars using waste expanded polystyrene(EPS) solution-based binders. The binders for polystyrene mortars are made by mixing crosslinking agent with waste EPS solutions which prepared by dissolving EPS in styrene. Polystyrene mortars are prepared with various EPS concentrations of EPS solutions and crosslinking agent contents, subjected to a dry curing, and tested for working life, peak exotherm temperature and 10h-length change. From the test results, the working lives of polystyrene mortars are shortened with raising EPS concentration of EPS solution and crosslinking agent content. Low-shrinkage or non-shrinkage of polystyrene mortars should be accomplished by adjusting EPS concentration of EPS solution and crosslinking agent content.

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A study on the Shrinkage Reduction and Strengths of Unsaturated Polyester Mortar (불포화 폴리에스테르 레진 모르타르의 수축저감 및 강도특성에 관한 연구)

  • 최낙운;최길섭;김완기;조영국;소양섭
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.343-348
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    • 1999
  • The purpose of this study is to evaluated the effects of added expanded polystyrene on the basic properties of UP mortar. Polyester resin mortars are prepared with expanded polystyrene ratio in styrene monomer (EPS/PS), and the ratio of total polystyrene resin to UP resin (PS/UP). And it is tested for viscosity of UP resin added PS resin, slump-flow test, working life, flexural and compressive strengths, and curing shrinkage test. From the test result, Viscosity of resin for polymer mortar increases with increasing PS content. Curing shrinkage of UP mortar is considerably smaller than that of plain UP mortar, nevertheless, reduction in the strengths is not recognized according to adding PS resin. In this study, we can obtain the optimum mix proportions of polymer mortar using PS resin.

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A Study on the Cushion Package Design of a Monitor using Finite Element Method (유한요소법을 이용한 모니터의 완충 포장재 설계에 관한 연구)

  • H.B.L.;Park, Sang-Hu;Kim, Won-Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.12
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    • pp.88-93
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    • 2000
  • The reduction of the cushion material such as Expanded Polystyrene (EPS) is one of the urgent tasks of the package design process in home electrical appliances considering environmental protection. EPS reduction often causes the structural damage of products, which must be protected in the environment of transportation. CAE simulation can help the efficient package design with low material cost. The mechanical drop simulation of packaged product was performed with commercial FEM code and Taguchi approach was used partially to determine the dominant design parameters. As results of this study, about 20% reduction of EPS was accomplished in the monitor package design.

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Analysis of Package Drop and its Application for Optical Disc Drives (광 디스크 드라이브용 완충포장재의 낙하충격 해석 및 활용)

  • 석기영;윤기원;나정민;박창배
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.177-182
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    • 2004
  • Electronic products are subjected to many different types of shock environment. As the Optical Disc Drive (ODD) market grows, the number of failures related to shock increases. Therefore, it is necessary to improve the performance of cushion package as well as the product design. Cushion materials such as expanded polystyrene are often used to protect electronic products from shock environment. In this paper, the drop analysis of the cushion package f3r optical disc drives was carried out with the explicit method of LS-DYNA and verified by the drop test. For the optimization of package, response surface approximation model was created using central composite design. As a result, cushioning performance was improved under the critical condition and practical design guidelines of cushion package were suggested.

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Experimental Study on the Heat Shielding Performance of Lightweight Foamed Concrete Using EPS beads. (EPS 비드를 사용한 경량기포콘크리트의 차열성능의 실험적 연구)

  • Hong, Snag-Hun;Song, Seung-Li;You, Nam-Gyu;Jung, Ui-In;Kim, Bong-Joo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.21-22
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    • 2018
  • Foamed concrete is a porous concrete that is cured by mixing bubbles into cement slurry. It is lighter than ordinary concrete and is characterized by higher insulation. Lightweight foamed concerte is mainly used as a sandwich panel in Korea, and is also used as a refractory filler in fireproof safes. Studies on lightwight foamed concrete have been carried out on strength,density and thermal conductivity. However, it is confirmed that the research on the fire resistance performance is very limited. Based on this study, fire resistance of lightweight foamed concrete using expanded polystyrene beads is investigated.

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