• Journal of the Korea Concrete Institute
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• v.17 no.3 s.87
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• pp.329-334
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• 2005

The use of Polymer Concrete (PC) is growing very rapidly in many structural and construction applications such as box culverts, hazardous waste containers, trench lines, floor drains and the repair and overlay of damaged cement concrete surfaces in pavements, bridges, etc. However, PC has a defect economically because resin which be used for binder is expensive. Therefore the latest research is being progressed to replace existing resin with new resin which can reduce the high cost. Here, Polymer concrete using the recycled PET(polyethylene terephthalate) has some merits such as decrease of environmental destruction, decrease of environmental pollution and development of new construction materials. The variables of this study are amount of resin, curing condition and maximum size of coarse aggregate to find out mechanic properties of this. Stress-strain curve was obtained using MTS equipment by strain control. The results indicated that modulus of elasticity was increased gradually in an ascending branch of curve, as an increase of resin content. Compressive strength was the highest for resin content of $13\%$. And Compressive strength was increased as maximum size of coarse aggregate increases. The strain at maximum stress increases with an increase of resin content and size of coarse aggregate. For the descending branch of stress-strain curve the brittle fracture was decreased when it was cured at the room temperature compared to high temperature.

• Journal of Adhesion and Interface
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• v.24 no.1
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• pp.17-25
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• 2023

In this study, waste polyethylene terephthalate (PET) was recycled to produce a support and then polyetherimide (PEI) was used for environmentally friendly organic solvent nanofiltration. The prepared composite membrane was first prepared by electrospinning a PET support, then casted on the support using PEI having excellent solvent resistance, and organic solvent nanoparticles using a Non-solvent Induced Phase Separation (NIPS) method. A filtration membrane was prepared. First, the fiber diameter and tensile strength of the PET scaffold prepared prior to membrane fabrication were identified through morphology analysis, and the optimal scaffold for the organic solvent nanofiltration membrane was identified. Afterward, the PET/PEI composite membrane prepared was checked for the DEA removal rate of Congo red having a molecular weight of 697 g/mol in ethanol to understand the performance as an organic solvent nanofiltration membrane according to the concentration of PEI. Finally, the removal rate of Congo red was 90% or more.

• Journal of Bio-Environment Control
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• v.14 no.4
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• pp.302-306
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• 2005

This Study was Conducted in 3 glasshouse to examine the Possibility for cultivation of plug seedlings using four growing media containing recycled PET-bottle-particles (PBT) as a medium component. Plug seedlings of 'Seokwang' tomato were grown in media containing $100\%$ PBT, $100\%$ peatmoss, or $50\%$ $PBT+50\%$ peatmoss. A commercial plug medium (Tosilee) was used as the control. All seeds were sown in 128 cell plug trays on July 12, 2004. Seedling growth was measured at 30 days after sowing. Percent seed germination was greater than 95% in all treatments. Plant height, shoot fresh and dry weights, leaf area, and hypocotyl length were the greatest in the control treatment. Root length and weight were the greatest in the $100\%$ PBT treatment, which had a medium pH of 7.3. Leaf area and shoot dry weight were greater in the $50\%$ $PBT+50\%$ peatmoss treatment, than in the $100\%$ PBT treatment, while they were the smallest in the $100\%$ peatmoss treatment. No toxicity symptoms caused by the use or PBT had been observed in any treatment. The results suggest a possibility of recycled PBT, a valuable reusable resource, to be used as a component for medium amendments in horticultural transplant production.

• Steel and Composite Structures
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• v.43 no.2
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• pp.257-270
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• 2022

Recycled aggregate concrete (RAC) is rarely used in load-carrying structural members. To widen its structural application, the compressive behavior of a promising type of composite column, steel-fiber reinforced polymer (FRP) double-tube confined RAC column, has been experimentally and analytically investigated in this study. The objectives are the different performance of such columns from their counterparts using natural aggregate concrete (NAC) and the different mechanisms of the double-tube and single-tube confined concrete. The single-tube confined concrete refers to that in concrete-filled steel tubular (CFST) columns and concrete-filled FRP tubular (CFFT) columns. The test results showed that the use of recycled coarse aggregates (RCA) affected the axial load-strain response in terms of deformation capacity but such effect could be eliminated with the increasing confinement. The composite effect can be triggered by the double confinement of the steel and carbon FRP (CFRP) tubes but not by the steel and polyethylene terephthalate (PET) FRP tubes. The proposed analysis-oriented stress-strain model is capable to capture the load-deformation history of such steel-FRP double-tube confined concrete columns under axial compression.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.292-295
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• 2004

Recently, polymer-clay hybrid materials have received considerable attention from both a fundamental research and application point of view. This organ-inorganic hybrid, which contains a nanoscale dispersion of the layered silicates, is a material with greatly improved thermal and mechanical characteristics. Two classes of nanocomposites were synthesized using an unsaturated polyester resin as the matrix and sodium montmorillonite as well as an organically modified montmorillonite as the reinforcing agents. X -ray diffraction pattern of the composites showed that the interlayer spacing of the modified montmorillonite were exfoliated in polymer matrix. The mechanical properties also supported these findings, since in general, tensile strength, modulus with modified montmorillonite were higher than the corresponding properties of the composites with unmodified montmorillonite. Adding organically modified clay improved the tensile strength of unsaturated polyester by $22\%$ and the tensile modulus of unsaturated polyester was also improved by $34\%$.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.72-72
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• 2012

본 연구에서는 친환경 리싸이클 섬유산업의 활성화를 위해 대학생들의 리싸이클 폴리에스터 섬유에 대한 인식도를 분석해 보고자 하였다. 측정 문항은 섬유전문가 3인의 검토를 거쳐 타당성을 확보하였으며, 조사는 질문지법으로 2011년 9월 1일부터 9월 10일까지 대전 거주 대학생을 대상으로 진행하였으며, 회수된 설문지 196부를 자료 분석에 이용하였고, SPSS 19 통계 패키지를 이용하여 자료를 통계분석하였다. 연구 결과는 다음과 같다. 1. 친환경적 의생활 실태 조사를 실시한 결과, 리싸이클 PET섬유에 대해 들어본 적이 있는 사람은 조사대상자의 27.6%로 나타났고, 그 정보원으로는 인터넷을 가장 많이 이용하는 것으로 나타났다. 2. 섬유소재별 친환경성에 대한 인식도를 조사한 결과, 대학생들은 리싸이클 PET섬유가 천연섬유보다 덜 친환경적이나, 인조섬유보다는 더 친환경적이라고 인식하는 것으로 나타났다. 3. 리싸이클 PET섬유에 대한 인식도를 요인분석한 결과, <친환경성 요인>, <촉감 요인>, <내구성 요인>, <기능성 요인>, <공정 요인>, <글로벌 경쟁력 요인>및 <부가가치성 요인> 등 7개의 요인이 도출되었는데 이는 대학생들은 리싸이클 PET섬유에 대해 친환경성, 촉감, 내구성, 기능성, 공정, 글로벌경쟁력, 부가가치성순으로 중요하게 인식하는 것으로 해석된다.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.138-148
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• 2003

In the study, current status of waste plastic recycling was investigated. Some factors to obstruct recycling of waste plastic was analyzed. These factors include the difficulty of obtaining location and man power, unclear marking of recyclable plastic and inefficient rate in producer and consumer deposit system. Life cycle assessment(LCA) study was performed to investigate the environmental impact of waste plastic(PET) recycling. When the recycled raw plastic material is used together with the virgin raw plastic material, all the environmental impact showed (-) value except ozone depletion impact category. The environmental avoided impact was the greatest in the global warming impact category. For active promotion of recycling activity, source separation system of waste plastic should be established first of all. Also, marking system of the recycling waste plastic should be made more clear so that consumers can understand it easily. Other strategies include the determination of decent rate for producer and consumer deposit system, establishment of infrastructure and information system for waste plastic recycling and citizen's cooperation through intensive public education.

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.244-248
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• 1998

The sound absorption materials are generally classified by three types, such as porous, resonator, panel. All of these types are based on theory of energy transform from sound energy to thermal energy. At first, the sound energy transform from the porous type uses to friction and viscose resistance. Secondly, resonator type uses to resonance frequency, absorption coefficient reach the highest.(omitted)

• Fashion & Textile Research Journal
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• v.9 no.4
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• pp.401-408
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• 2007

The study aims to examine consumer awareness of green fashion products and demographic characteristics by subdividing environmentally conscious consumers of such products in the current domestic fashion market. It then compares the result with the characteristics of environmentally conscious consumers studied by 1999 in order to understand the trend of the consumer group in the fashion market and to promote the use of green fashion products. Marketing strategies for green fashion products suggested by the study are as follows: First, fashion firms are required to develop and publicize shops selling recycled or second-hand clothing that environmentally conscious consumers show constant interest. For instance, clothing patterns may be developed to enable consumers to make their kids' clothing easily at home, and various garments made from recycled materials may stimulate environmentally conscious consumers' desire to buy. Particularly, advanced technologies should be developed and publicized to manufacture garments that can excel existing ones made of normal materials in their features in order to satisfy consumers' interest in clothing made from recycled PET bottles. In addition, various natural dyes should be developed to decrease water pollution. Second, it seems imperative to develop clothing made of recycled knitted apparel that attracts consumers' interest more than ever, fashionable multi-purpose clothing, and environmentally friendly materials. As the use of natural fur or leather can cause the endangerment of wild animals and the destruction of the ecosystem, synthetic fur or leather may be used to develop sophisticated products with the same texture as real ones to attract environmentally conscious consumers' interest.

• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.79-87
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• 2004

The qualify of lightweight aggregate made from waste PET bottle(WPLA) and the workability, the unit weight and strength property of concrete with WPLA were investigated for the purpose of recycling the waste PET bottles as lightweight concrete fine aggregate. This study indicated a good result that WPLA should be replaced with less than $50\%$ of natural fine aggregate. When WPLA was replaced with $50\%$ of natural fine aggregate, the specific gravity and water absorption of mixed fine aggregate were greatly reduced about 23 and $75\%$ respectively in comparison with those of river sand. The quality of WPLA affected on the properties of lightweight aggregate concrete. The workability of fresh concrete with WPLA(WPLAC) was improved with increasing the replacement ratio of WPLA and water cement ratio. Slump increasing ratio of the former showed about $45 {\~} 120\%$ because that a specific gravity of fine aggregate was decreased from 2.6 to 1.7. The unit weight of concrete with $75\%$ WPLA was decreased about $17\%$ in comparison with that of control concrete. Furthermore, the compressive strength of concrete with 25 and $50 \%$ WPLA at the age of 28 days increased higher than 30 MPa regardless with water cement ratio (W/C=45, 49 and $53\%$) of this study. Specific strength of concrete with $25\%$ WPLA, $15.11{\times}10^3 MPa{\cdot}m^3/kg$, was higher than that of contro concrete in water cement ratio of $49\%$. The compressive strength-splitting tensile strength ratio and compressive strength-modulus of elasticity ratio of WPLAC were similar to that of nomal lightweight aggregate concrete. This results showed a good estimation that WPLA will be able to recycled as a fine aggregate for lightweight concrete.