• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.129-134
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• 2019

PVC was chosen as a plastic product that can cope with lead, a radiation shielding material that is widely used in medical institutions. In addition to radiation shielding clothing, we want to evaluate whether it can be used as a medical device component and industrial shielding material in low dose areas. Commercial PVC has a density of 3.68 g/㎠ and can be positively expected sufficient shielding effect in certain radiation areas such as material flexibility and economy efficiency, and can be transformed into various forms and used as a lightweight shielding wall. The shielding performance was tested by adjusting the thickness of 5 sheets of 3mm PVC in the range of medical radiation used for clinical examination in medical institutions. Shielding performance against effective energy was evaluated based on tube radiation voltage of medical radiation. The thicker the PVC, the lower the tube voltage and the lower the effective energy, the greater the shielding effect. The shielding effect was 70% at 12mm thickness and 80kVp tube voltage. Therefore, the shielding effect of PVC material has a high dependence of thickness. In the future, continuous research is needed to make thin and light eco-friendly products while improving shielding performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.59-65
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• 2019

The EMI shielding effectiveness of shielding layers thickness was analyzed when the low conductivity shielding layers was placed in the near field of the noise source. A spiral antenna with broadband characteristics was used as the noise source, and graphite was selected as the low conductivity shielding material. Two spiral antennas were constructed to analyze the transmission coefficient between two antennas, and the distances between the transmitting and receiving antennas were 5 cm and 10 cm. The thickness of the shielding layers was changed from 1 um to 200 um. The frequency was changed from 100 MHz to 6 GHz to obtain a maximum SE(Shielding Effectiveness) of 70 dB. In this simulation, electronic shielding was used due to the nature of graphite, which is a shielding film material. Based on these results, we will study how to improve the shielding performance by implementing magnetic shielding in the future.

• Journal of the Korea Convergence Society
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• v.12 no.1
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• pp.105-110
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• 2021

Radiation shielding of affinity material, which is widely used in medical institutions, is made in sheet form and is mainly applied to apron. Shielding performance is presented based on lead equivalent, and is presented as 0.25-0.50mmPb. In the case of shielding materials where lead is used as the main material, the shielding performance can be adjusted by thickness due to the excellent machinability of lead. However, eco-friendly shielding sheets are difficult to control shielding performance based on thickness criteria as shielding performance varies depending on the content of shielding materials, the properties of polymeric materials that are base materials, and the technical differences in the process. In this study, shielding sheets were manufactured based on thickness to solve these problems and the shielding performance was compared in this study. As a result, it was shown that the laminated structure shielding sheet was more effective.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.129-136
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• 2011

In this paper, the shielding material for the product design of various electrical appliances is suggested by more environmentally materials like as the lacquer and the charcoal. The suggested shielding material has the shielding effectiveness of 97.2%, 98.7%, and 96.3% at 900 MHz, 1.8 GHz, and 2.45 GHz, respectively. In the microwave oven and the cell phone, the metal or metal-coated plastic are used for the shielding of strong electromagnetic wave. However, by using more environmentally materials like as the lacquer and the charcoal, the products can be manufactured more light weighting, more heat-resisting, more abrasion resisting, and more corrosion resisting. Also, the products design can be varied more mellow and more friendly.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.83-88
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• 2020

Recently, radiation shielding sheets made of eco-friendly materials have been widely used in medical institutions. The shielding sheet is processed into a solid form by thermoforming by mixing a shielding material with a polymer material. The base is resin-based and has a limit in tensile strength, and for this purpose, fibers such as non-woven fabrics are used on the surface. The shielding sheet process technology has a problem in that the tensile strength rapidly decreases when the content of the shielding material is increased to increase the shielding performance. In order to improve this, this study intends to compare and evaluate the method of laminating and coating the fibers in the sheet process. In comparison of the three types of sheets, there was no difference in shielding performance between the fiber-coated sheet and the compression sheet, but there was a large difference in tensile strength.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.283-292
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• 2022

Advanced radiation applications have been widely used and extended to many fields. As a result of this fact, choosing an appropriate shielding material based on the radiation application has become vital. In this regard, the integration of elements into polymer composites has been investigated and contributed to the quantity and quality of radiation shielding materials. This study reports photon attenuation parameters and electromagnetic shielding effectiveness of a novel polymer composite prepared with a matrix reinforced with three different proportions (5, 10, and 15 wt%) of niobium content. Addition of Nb dopant improves both photon attenuation and electromagnetic shielding effectiveness for the investigated composites. Therefore, Nb(15%) polymer composite with highest concentration has been found to be the best absorber for ionizing and non-ionizing radiations. Consequently, the performed analyzes provide evidences that the prepared Nb-reinforced polymer composite could be effectively used as photon radiation attenuator and electromagnetic shielding material.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4664-4670
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• 2023

Radiation is the main safety issue for almost all nuclear applications, which must be controlled to protect living organisms and the surrounding materials. In this context, radiation shielding materials have been investigated and used in nuclear technologies. The choice of materials depends on the radiation usage area, type, and energy. Polymer materials are preferred in radiation shielding applications due to their superior characteristics such as chemical inertness, resistivity, low weight, flexibility, strength, and low cost. In the presented work, ABS polymer material, which is possibly the most commonly used material in 3D printers, is mixed with Gd₂O₃ and Er₂O₃ nanoparticles. ABS filaments containing these rare-earth elements are then produced using a filament extruder. These produced filaments are used in a 3D printer to create shielding samples. Following the production of shielding samples, SEM, EDS, and gamma-ray shielding analyses (including experiments, WinXCOM, GEANT4, and FLUKA) are performed. The results show that 3D printing technology offers significant enhancements in creating homogeneous and well-structured materials that can be effectively used in gamma-ray shielding applications.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1538-1540
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• 1999

For the development of electro magnetic shielding materials by use of the conductive polymer, measuring technique related to their shielding effect should be well established. For this propose, several commercialized techniques based on different conception have been well compared in order to adopt appropriate method to our materials under development and then, flanged coaxial holder type fixture device has been fabricated and tested satisfied performance has been obtained showing over 90dB in dynamic range with accuracy of +/-2dB.

• Laser Solutions
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• v.10 no.4
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• pp.1-6
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• 2007

This study includes the effects of shielding gas types and flow rate on Nd:YAG Laser weldability of sintered material. The types of shielding gas were evaluated for He, Ar and N2. Bending strength, porosity rate, hardness and aspect ratio testing of laser weld are carried out to evaluated the weldability. As a results, Ar gas was showed the best welding strength even it has the most porosity content on weld metal, and depend on increases the gas flow rate, it was not only got deeper penetration depth but also showed higher bending strength. Therefore we could know that bending strength is not only affect the porosity content but also melting area.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.3
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• pp.207-214
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• 2001

The conductive polymers, polyaniline (PANI) emeralidin base and 3,4-polyethylene dioxythiophene(PEDOT) were synthesized and coated on the PET film dealt with acryl type primer to study the electromagnetic shielding effectiveness. When both PANI and PEDOT were coated on the PET film dealt with acryl type priemer, their surface properties such as he adhesive increased. For PANI, when blended with the binder such as PMMA, it adhesive and surface hardness increased, too. The visible light transmittance decreased, while the electromagnetic shielding effectiveness increased, when coated thickness of PANI and PEDOT increased. For PANI, the electromagnetic shielding effectiveness increased as its surface resistance decreased. For PANI, when the surface resistance was 140 Ω/$\square$, the shielding effectiveness was found to be 11 dB in the far field, and 13 dB in the near field at 1 GHz. For PEDOT, when the surface resistance was 200 Ω/$\square$, the shielding effectiveness was found to be 3 dB in the far field, and 7dB in the near field.