• Title/Summary/Keyword: 차폐막

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The Characterization of Electromagnetic Shielding of $SiO_2$/ITO Nano Films with Transition Metal Ions (전이금속이 첨가된 $SiO_2$/ITO 나노박막의 전자파 차폐특성)

  • 신용욱;김상우;손용배;윤기현
    • Journal of the Korean Ceramic Society
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    • v.38 no.1
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    • pp.15-21
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    • 2001
  • 전자파 차폐 및 반사방지용으로 사용되는 SiO$_2$/ITO 이층박막의 전기적 특성에 미치는 전이금속이온의 영향에 대해 고찰하고 전자파 차폐이론식으로부터 박막의 전도특성에 모사하여 효과적인 전자파 차폐효과를 얻기 위한 전도막을 설계하고자 하였다. ITO 상층부에 전이금속염을 첨가한 실리카 복합졸을 코팅하여 SiO$_2$/ITO 이층막을 제조한 결과 최저 표면저항치를 나타내는 첨가량은 전이금속의 종류에 따라 차이를 보이지만 Sn 및 Zn이 첨가된 졸로부터 형성된 박막은 $10^{5}$Ω/$\square$ 이하의 낮은 저항치를 보였으며 가장 안정된 표면저하을 나타내었다. 또한 전자파 차폐효과와 전도박막의 표면저항을 차폐이론식으로부터 모사한 결과 Zn과 Sn의 전이금속염이 첨가된 SiO$_2$/ITO 투명전도막은 TCO99에서 정한 전자파 차폐기준에 부합하였다.다.

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Comparative study on absorbable periodontal tissue regeneration barrier membranes (흡수성 치주조직 재생 차폐막에 대한 비교연구)

  • Youngchae Cho;Dayeon Jeong;Deuk Yong Lee
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.33 no.2
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    • pp.71-77
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    • 2023
  • Absorbable periodontal tissue regeneration barrier membranes (total 6; domestic 4; import 2) were comparatively analyzed. In the case of the xenograft barrier membrane, the collagen product had excellent tensile strength but low strain, and the porcine pericardial membrane had good mechanical properties, but its thickness was too thick to control. The synthetic PLLA membrane manufactured by the electrospinning had a relatively low water absorption capacity. However, the hybrid barrier membrane was able to control mechanical properties and biocompatibility through proper mixing of synthetic polymer and natural polymer. DA02 (PLLA/gelatin), a newly developed hybrid absorbable periodontal tissue regeneration membrane that is entirely dependent on imports, can be applied to an absorbable periodontal tissue regeneration barrier membrane due to suitable mechanical properties and biocompatibility.

An Accurate Method to measure Shielding Effectiveness of EMI Spray Coating Film (EMI 스프레이 코팅막의 차폐효과를 측정하기 위한 정확한 방법)

  • Hur, Jung;Lee, Won-Hui
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.4
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    • pp.79-83
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    • 2018
  • An accurate method to measure shielding effectiveness(SE) of EMI spray coating film is presented. After high frequency simulating, Circular coaxial standard test fixture is fabricated. A sample of EMI spray coating film was fabricated for insertion into a circular coaxial standard test fixture. The measuring instrument used an Agilent 8722ES vector network analyzer for the SE measurement. The exact SE of copper and silver mixed spray coating sample was measured by the composition of the measuring instrument and the measuring sample. The SE of copper sample was measured at 70 dB and the SE of copper and silver mixed spray coating sample was measured at 60 dB. As a result of the measurement, the reliability of the circular coaxial standard test fixture was confirmed.

THE INVESTIGATION OF MICROVASCULATURE CHANGES IN OSSEOUS REGENERATION BY GUIDED TISSUE REGENERATION PROCEDURE (골재생유도술에 의한 골재생시 미세혈관 구축 양상)

  • Choi, Du-Hee;Ryoo, Hyun-Mo;Shin, Hong-In
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.21 no.3
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    • pp.257-265
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    • 1999
  • To investigate the sequential changes in microvascular architecture and osseous regeneration during the bony healing after an application of the guided tissue regeneration method, we made artificial defects measuring $0.7cm{\times}0.3cm$ in size on femoral bones of rats measuring about 200gm and applied non-absorbable TEFE membrane at experimental sites but not at control sites. Then we observed the sequential changes and correlations between new vacuolation and bony regeneration using microvascular corrosion cast method and routine light microscopic observation at 1, 2 and 3 weeks after operation, respectively. The results showed that there were close relationships between regeneration of microvasculature and bone. In early phase, the invasion of granulation tissue at control sites delayed bony regeneration, however, in later phase, there was no remarkable differences in bony regeneration between control and experimental sites. The placement of barrier also affected in revascularization of regenerating bony defects. This is, the experimental sites showed parallel arranged nutritional vessels along long axis with well developed retiform plexus whereas the control revealed vertical invasion of microvasculature from outside of marrow space through bony defects which was also rearrange with time into parallel pattern with a vertical plexus but lesser organized than that of experimental sites. These findings suggest that the reconstruction of regenerating vasculature within the marrow cavity only may be sufficient and/or more be efficient in regeneration of bony defects.

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