• 제목/요약/키워드: absorbers

검색결과 385건 처리시간 0.033초

A Study on Multi-Layered EM Wave Absorber Using Natural Lacquer as a Binder

  • Choi, Dong-Han;Kim, Dong-Il;Choi, Chang-Mook;Li, Rui
    • 한국항해항만학회지
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    • 제30권9호
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    • pp.767-772
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    • 2006
  • Generally, a silicone rubber and a chlorinated polyethylene(CPE) have been used as a binder for the development of high-performance composite EM(Electro Magnetic) wave absorbers. In this paper, the EM wave absorption performance of natural lacquer, which is newly proposed as a binder was investigated. The prepared MnZn ferrite EM wave absorbers are mixed with natural lacquer showed excellent EM wave absorption characteristics compared with MnZn ferrite EM wave absorbers which are mixed with the conventional binders. MnZn ferrite EM wave absorbers mixed with natural lacquer were prepared and their absorption ability was also investigated The EM wave absorbers are fabricated in different proportions of MnZn, or NiZn ferrite and natural lacquer, and their reflection coefficients are measured. The permittivity and permeability are calculated by using the measured reflection coefficients. The EM wave absorption abilities are calculated according to different thicknesses of the EM wave absorbers.

유한요소법을 이용한 MR 쇽 업소버의 최적설계 (Optimal Design of MR Shock Absorbers Using Finite Element Method)

  • 성금길;최승복
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.375-380
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    • 2007
  • This paper presents optimal design of controllable magnetorheological (MR) shock absorbers for passenger vehicle. In order to achieve this goal, two MR shock absorbers (one for front suspension; one for rear suspension) are designed using an optimization methodology based on design specifications for a commercial passenger vehicle. The optimization problem is to find optimal geometric dimensions of the magnetic circuits for the front and rear MR shock absorbers in order to improve the performance such as damping force as an objective function. The first order optimization method using commercial finite element method (FEM) software is adopted for the constrained optimization algorithm. After manufacturing the MR shock absorbers with optimally obtained design parameters, their field-dependent damping forces are experimentally evaluated and compared with those of conventional shock absorbers. In addition, vibration control performances of the full-vehicle installed with the proposed MR shock absorbers are evaluated under bump road condition and obstacle avoidance test.

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자기유변유체를 이용한 승용차량 쇽 업소버의 유한요소 최적설계 (Optimal Design of Magnetorheological Shock Absorbers for Passenger Vehicle via Finite Element Method)

  • 성금길;최승복
    • 한국소음진동공학회논문집
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    • 제18권2호
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    • pp.169-176
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    • 2008
  • This paper presents optimal design of controllable magnetorheological(MR) shock absorbers for passenger vehicle. In order to achieve this goal, two MR shock absorbers (one for front suspension; one for rear suspension) are designed using an optimization methodology based on design specifications for a commercial passenger vehicle. The optimization problem is to find optimal geometric dimensions of the magnetic circuits for the front and rear MR shock absorbers in order to improve the performance such as damping force as an objective function. The first order optimization method using commercial finite element method(FEM) software is adopted for the constrained optimization algorithm. After manufacturing the MR shock absorbers with optimally obtained design parameters, their field-dependent damping forces are experimentally evaluated and compared with those of conventional shock absorbers. In addition, vibration control performances of the full-vehicle installed with the proposed MR shock absorbers are evaluated under bump road condition and obstacle avoidance test.

센더스트를 이용한 적층형 전파흡수체의 개발 (Development of Multi-layer Electromagnetic wave Absorbers Using Sendust)

  • 류재민;김동일;제승훈
    • 한국항해항만학회지
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    • 제30권8호
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    • pp.637-642
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    • 2006
  • 본 논문에서는 두 종류의 재료에 대한 실험이 진행되었다. 첫째, 센더스트를 이용한 적층형 전파흡수체를 연구하였다. 그 결과, 적층형 센더스트 전파흡수체는 5-Band에서 10dB 대역폭이 확장되었다. 둘째, 적층형 센더스트 전파흡수체에 수산화알루미늄의 혼합 효과를 연구하였다. 그 결과, 수산화알루미늄을 혼합한 적층형 센더스트 전파흡수체는 수산화알루미늄을 혼합하지 않은 적층형 센더스트 전파흡수체와 비교해서 5-Band에서 10dB 대역폭이 확장하였다.

Paint형 전파 흡수체의 전파 흡수 성능 향상에 관한 연구 (A Study on the Improvement of EM Wave Absorption Characteristics in Paint-type EM Wave Absorbers)

  • 제승훈;김동일;최정현
    • 한국전자파학회논문지
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    • 제17권4호
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    • pp.330-334
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    • 2006
  • 본 논문에서 Sendust, Mn-Zn, Ni-Zn, Ba, Sr Ferrite를 사용하여 페인트형 흡수체를 제작하였다. 지지재로서는 enamel, epoxy, urethane 페인트들을 사용하여 각각 흡수능을 측정하였다. 그리고 $Al(OH)_3$으로 코팅한 흡수체의 대역폭은 코팅을 하지 않은 것보다 더 넓어지는 것을 알 수 있다. 또 2 mm 두께의 적층형 흡수체는 X-band에서 대략 20 dB의 흡수능을 보여준다.

A Study on Multi-Layered EM Wave Absorber Using Natural Lacquer as a Binder

  • Choi, Dong-Han;Kim, Dong-Il;Choi, Chang-Mook;Li, Rui
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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    • pp.157-161
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    • 2006
  • Generally, a silicone rubber and a chlorinated polyethylene(CPE) have been used as a binder for the development of high-performance composite EM(Electro Magnetic) wave absorbers. In this paper, the EM wave absorption performance of natural lacquer, which is newly proposed as a binder was investigated. The prepared MnZn ferrite EM wave absorbers are mixed with natural lacquer showed excellent EM wave absorption characteristics compared with MnZn ferrite EM wave absorbers which are mixed with the conventional binders. MnZn ferrite EM wave absorbers mixed with natural lacquer were prepared and their absorption ability was also investigated. The EM wave absorbers are fabricated in different proportions of MnZn, or NiZn ferrite and natural lacquer, and their reflection coefficients are measured. The permittivity and permeability are calculated by using the measured reflection coefficients. The EM wave absorption abilities are calculated according to different thicknesses of the EM wave absorbers.

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자외선 흡수제 처리 시 은나노/수지 첨가가 면직물의 기능성에 미치는 영향 (Effect on Functional Properties of the Cotton Fabrics Treated by UV-absorbers with Nanosilver/DMDHEU Treatment)

  • 강미정;권영아
    • 한국의류학회지
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    • 제33권9호
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    • pp.1463-1471
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    • 2009
  • Silver ions or silver nanoparticles have multi-functional properties. The cotton fabrics for providing multi-functional properties were treated with a nanosilver powder, UV-absorbers, and dimethyloldi-hydroxyethyleneurea (DMDHEU) alone and mixed solution. The physical properties, UV protection, antibacterial, and deodorizing properties of treated cotton fabrics were evaluated. The results were as a follows. The UV protection of cotton fabrics were increased by the application of a nanosilver and Uv-absorbers mixture. The UV protection of treated fabrics were improved by nanosilver/DMDHEU/UV-absorbers mixed solution. The wrinkle recovery properties of fabrics treated with DMDHEU and nanosilver improved. The stiffness of fabrics are decreased by a nanosilver/DMDHEU/UV-absorbers mixed solution. The antibacterial properties of the fabrics treated with nanosilver/DMDHEU/UV-absorbers mixed solution is 99.99%. The functional properties of cotton fabrics are shown to be better with aanosilver/DMDHEU/UV-absorbers mixed than treated with nanosilver alone.

Sendust를 이용한 적층형 전파흡수체의 개발 (Development of Multi-layer Electromagnetic wave Absorbers Using Sendust)

  • 류재민;김동일;제승훈
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2006년도 춘계학술대회 및 창립 30주년 심포지엄(논문집)
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    • pp.97-101
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    • 2006
  • 본 논문에서는 센더스트를 이용한 적층형 전파흡수체를 제안하였다. 적층형 센더스트 전파흡수체는 S-Band에서 10 dB 대역폭이 확장되었다. 그리고 우리는 적층형 센더스트 전파흡수체에 수산화알루미늄의 혼합 효과를 연구하였다. 그 결과, 수산화알루미늄을 혼합한 적층형 센더스트 전파흡수체는 수산화알루미늄을 혼합하지 않은 적층형 센더스트 전파흡수체와 비교해서 S-Band에서 10 dB 대역폭이 확장하였다.

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Coating Effects on Electromagnetic Wave Absorbers Prepared with Mn-Zn Ferrites

  • Song Jae-Man;Kim Dong-Il;Che Seung-Hun;Choi Yun-Seok;Kim Ki-Man;Rhyu Keel-Soo
    • Journal of electromagnetic engineering and science
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    • 제5권4호
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    • pp.161-165
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    • 2005
  • We prepared Mn-Zn ferrite Electromagnetic(EM) wave absorbers. The Mn-Zn ferrite EM wave absorbers were coated with Sr ferrite powders and $Al(OH)_3$ powders. The coated Mn-Zn ferrite EM wave absorbers show improved absorption compared with non-coated Mn-Zn EM wave absorbers.

휴대전화 단말기용 전파흡수체의 개발에 관한 연구 (A Study on Development of EM Wave Absorbers for Mobile Phones)

  • 정재현;김동일
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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    • pp.67-68
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    • 2005
  • This thesis is concerned with basic research for development of EM wave absorbers in sheet type for mobile phones. By controlling the sendust ratio, the $Al(OH)_3$ coating, the thickness, the kind of binders, EM wave absorbers were prepared and examined. Centeral frequency shifts toward lower with increasing thickness of the absorber, and absorption ability controlled to adjust Sendust amount. The absorption band of the EM wave absorber coated with $Al(OH)_3$ becomes larger than that of non-coated one. Sendust composite microwave absorbers mixed with CPE were prepared at $70^{\circ}C$ in temperature. The fabricated EM wave absorbers show a reflection coefficient 5.56 dB at 1.8 GHz in thickness of 0.85 mm.

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