• Composites Research
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• v.24 no.6
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• pp.25-30
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• 2011

This paper presents an experimental study on the enhancement of electromagnetic shielding (EMI) properties of glass fiber, carbon fiber, and glass-carbon fiber composites by adding layers of multi-walled carbon nanotubes (MWCNTs). In the case of glass-fiber composites, spraying 0.1~0.2 g of MWCNT over a fiber area of $200mm{\times}200mm$ (1.8~3.6 ${\mu}m$ in thickness) resulted in significant improvement in EMI shielding effectiveness (SE). Also, when applying multiple MWCNT layers, it was more effective to place the layers concentrated near the center of the composite rather than spreading them out. On the contrary, inherently conductive carbon fiber and glass-carbon fiber composites did not show appreciable improvement with the addition of MWCNT layers. In order to maximize the effectiveness of carbon nanomaterials as EMI shielding fillers, it is imperative to understand the effect of these materials on various EMI shielding mechanisms and their interactions.

• Electrical & Electronic Materials
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• v.13 no.2
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• pp.37-42
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• 2000

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.05a
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• pp.74-74
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• 1997

• Electrical & Electronic Materials
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• v.31 no.2
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• pp.8-15
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• 2018

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.11a
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• pp.78-78
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• 1998

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.2 no.2
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• pp.25-29
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• 1991

In this paper, laminated shielding effectiveness equation is derived from basic shielding theory and this equation is applied to calculate the shielding effectiveness for two typical non-magnetic shielding materials, Aluminium and steel, when they are coated with conductive paint.

• 대한방사선방어학회:학술대회논문집
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• 2011.11a
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• pp.348-349
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• 2011

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.105-110
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• 2004

방사선 투시조영 촬영 시 사용되는 방호복의 차폐효율 증가와 경량화는 오랜 시간 연구 대상이 되었다. 이러한 방호복의 질적 향상을 위하여 연구한 결과는 다음과 같다. Apron의 규격인 납 당량 0.25mm에 해당하는 투과선량은 5.2%로 나타났으며, 시료 Sn, Ni, Ti, Cu의 방사선 차폐 효율은 Sn이 가장 높게 나타났다. 증착시료 Sn+Pb 방법에서는 Sn 0.18mm와 Pb 0.1mm, Pb+Sn 방법에서는 Pb 0.1mm와 Sn 0.36mm에서 Apron의 규격인 납 0.25mm 두께로 나타났다. 증착시료 Sn+Pb는 Apron의 규격인 0.25mm 납 당량보다 차폐효율이 높고, 면적당 무게가 가벼워 방호복 물질로 적합한 것으로 사료된다.

• Journal of the Korea Convergence Society
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• v.12 no.10
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• pp.129-136
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• 2021

Radiation shields used in medical institutions mainly use lead to manufacture products and fitments. Although lead has excellent processability and economic efficiency, its use is being reduced due to environmental issues when it is disposed of. In addition, when used for a long time, there is a limit to using it as a shielding film, shielding wall, medical device parts, etc. due to cracking and sagging due to gravity. To solve this problem, copper, tin, etc. are used, but tungsten is mostly used because there is a difficulty in the manufacturing process to control the shielding performance. However, it is difficult to compare with other shielding materials because the characteristics according to the type of tungsten are not well presented. Therefore, in this study, a medical radiation shielding sheet was manufactured in the same process using pure tungsten, tungsten carbide, and tungsten oxide, and the particle composition and shielding performance of the sheet cross-section were compared.As a result of comparison, it was found that the shielding performance was excellent in the order of pure tungsten, tungsten carbide, and tungsten oxide.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.949-956
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• 2021

The purpose of this paper is to evaluate whether tungsten nanoparticles have a shielding effect on scattered light generated at high doses as an alternative material to lead used to shield scattered light in electron beam therapy. A plate was manufactured to set the position of the dosimeter and the size of the radiation field to be constant. The glass dosimeter was placed at 12 points, which were 1, 2, and 4 cm apart from the center of the field of 10 × 10 cm² in the cross direction. A total of 12 types of tungsten nanoparticle shields were developed with a thickness of 0.75 mm to 4.00 mm and a size of 10 × 10 cm² using 0.4, 0.75, and 1 mm materials. Using a linear accelerator, measurements were made four times at 6 MeV and four times at 12 MeV, and the dose intensity was investigated at 100 MU. The 4 mm shielding plate showed the highest shielding effect at 1 cm from the irradiation field. The 1 mm shielding plate at 2 cm from the irradiation field had the lowest shielding effect. As the thickness of the tungsten shielding plate increased, the electron beam's shielding effect increased sharply. It was confirmed that tungsten nanoparticles can reduce the amount of scattered light generated by electron beam therapy. Therefore, this study will provide basic data when follow-up studies are conducted on the shielding ability of tungsten nanoparticles.