• Resources Recycling
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• v.24 no.6
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• pp.45-53
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• 2015

There are few studies on the effects of different sources of PVC scraps generated after the end-of-life PVC products and these scraps are used to prepare PVC products of low quality. In this paper, rigid PVC scraps from different sources such as clothes, pipes, and others were investigated to incorporate into virgin PVC compounds as a part of efforts to recycle various PVC scraps effectively. It was found that the tensile strength and impact strength of the PVC compounds generally decreased with increasing the content of PVC scraps. The impact properties of scrap were in order of CC > PC > RC, tensile strength were PC > CC > RC and Vicat softening temperature shows no specific tendency. CC scraps contents of 50 phr of virgin PVC resin showed 80 %, and PC scrap with 50 phr of virgin resin showed 50% of the mechanical properties with virgin PVC.

• Design & Manufacturing
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• v.2 no.4
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• pp.54-61
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• 2008

Warpage, which is one of the molding trouble, acts as possible factor which results in defect in assembly. In this study, a mold was designed to produce specimens with rib parallel to flow direction, specimens with rib perpendicular to flow direction and specimens without rib. This work researched change of warpage according to injection molding condition such as injection pressure, packing pressure, packing time, resin temperature, mold temperature in non-crystalline resins(PC, ABS), crystalline resins(PP, PA66), and 30% glass fiber reinforced-resins(PC, ABS, PP, PA66).Specimens with rib and Crystalline resins show more warpage than specimens without rib and non-crystalline resins, respectively. Glass fiber reinforced-resins and specimens with rib parallel to flow direction show smaller warpage than conventional resins and specimens with rib perpendicular to flow, respectively. Specimens with rib and specimens without rib show reduced warpage as packing time increases. In addition, warpage increase as resin temperature increases. It is found that CAE shows similar tendency with experiment as packing time, resin temperature. when the rib is caused, warpage will reduce and prevent the transformation. product of a irregular form occurs warpage. In the study It'll be basic data that product occurs warpage, preferablity.

• Composites Research
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• v.15 no.6
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• pp.1-7
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• 2002

In VARTM process where a sacrificial medium is used to facilitate the resin flow, the velocity of resin varies drastically between the sacrificial medium and the fiber preform. Although the thickness-to-length ratio of a VARTM product is usually small, a 3-D analysis is prerequisite to analyze the lead-lag flow in the two different media. The problem associated with the full 3-D analysis is the CPU time. A full 3-D numerical mesh comprising large number of nodes requires an impractical CPU time on average computer platforms. In this study, a dual-scale analysis technique was developed. The flow analysis for the entire calculation domain was conducted in 2.5-D, and the 3-D analysis was performed for a small area of special concern. In some numerical examples, the local 3-D analysis could discover an eccentric flow pattern as well as the lead-lag flow that will inevitably be neglected in 2.5-D simulations. The global-local analysis technique practiced in this study can be used to analyze the intricate flow of resin through non-uniform media in affordable CPU times.

• Design & Manufacturing
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• v.9 no.1
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• pp.14-17
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• 2015

In the data from synthetic resin makers, there is no shrinkage deviation through injection molding. But, after making the required products, even in the same conditions, there are some size-deviation in colors. Into our research, we checked main factor by the injection molding conditions. Our tests have shown this results, there are some shrinkage deviation in collors and, in the injection molding conditions, packing pressure is the main factor.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.319-324
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• 2014

The wafer carrier is made of PP, PC, PE resin which have excellent heat and chemical resistance and electrical properties. However, particle generation has become a problem due to static electricity generated in the carrier. Some conductive material such as carbon black (CB) and carbon fiber (CF) are added for the purpose of anti-static, however, additional for motility and particle contamination problems due to high carbon content occurs. In this paper, the electrical characteristics and workability are observed and compared by adding low Carbon Nono Tube(CNT) to each PP, PC and PE resin to solve the problem.

• Carbon letters
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• v.1 no.3_4
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• pp.133-137
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• 2001

Mesoporous activated carbon fiber (ACF) was prepared from phenolic resin containing a small amount (0.1 wt %) of organic nickel complex through carbonization and steam activation. Microporous ACF as reference sample was also prepared from phenolic resin without agent. In both cases of the mesoporous ACFs and the microporous ACFs, the electric double layer capacitance of the nonaqueous electrolyte (0.5 M $TEABF_4$/PC or 1.0 M $LiClO_4$/PC) was not proportional to the BET specific surface area. This is owing to the low permeability of nonaqueous electrolyte or the low mobility of ion in narrow micropores. However, the mesoporous ACF showed higher double layer capacitance than the microporous (normal) ACF. This result suggests that the presence of many mesopores promotes the formation of effective double layer or the transfer of ion in the micropore.

• Journal of the Semiconductor & Display Technology
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• v.3 no.4
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• pp.5-11
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• 2004

Optical properties of PET(Polyethylene terephthalate), PC(Polycarbonate), Acrylic resin and PE(Polyethylene) sheets were studied as a function of heat treating temperature of $60^{\circ}C$ to $150^{\circ}C$. By the heat treatment, optical properties of transmittance, absorbance, and reflectance showed a considerable change with different ways according to the materials. To understand the reason of optical property change, X-ray diffraction and surface morphology were also investigated. It was observed that small crystallite and pore that can cause scattering largely affect the transmittance. It was suggested that change of surface chemical bond induce the reflectance variation.

• Proceedings of the Korea Concrete Institute Conference
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• 1990.04a
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• pp.1-4
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• 1990

This study was conducted to evaluate strength characteristics of various polymer concretes which were produced using materials available in Korea. Compressive strength, splitting tensile strength and flexural strength were evaluated in this study. Eight different polymer binders were used, including two types of epoxy resin, five types of unsaturated polyester resin, and a type of MMA monomer. The results of this study showed that the product made from PC-100 of SH company was the best performing concrete. However, since this result was based on strength and economics point of view, further study has to be conducted for comprehensive analysis.

• The Korean Journal of Applied Statistics
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• v.27 no.4
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• pp.543-552
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• 2014

High bandwidth RF such as Bluetooth, GPRS, EDGE, 3GSM, HSDPA is papular in the mobile phone market. A non-conducting metal coating process requires an e-beam deposition of metal, two steps of UV hard coating primer and top coating; however, it is inefficient. We navigate to the electron beam irradiation conditions(resin surface treatment conditions) in the PC/ABS resin injection process. By analyzing the experimental results, we find the optimum development conditions for the electro deposition pre-treatment process and mass production lines using the plasma generated electron beam source.

• 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.