• 제목/요약/키워드: permeability ratio (PR)

검색결과 3건 처리시간 0.017초

배수용 Geotextlle의 평면투수 성능분석 (Analysis on Character and Ability of In -Plane Permeability of Geotextiles Used for Darainage)

  • 이상호
    • 한국지반공학회지:지반
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    • 제8권3호
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    • pp.61-74
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    • 1992
  • Geoteztile drain의 설계를 위한 기초자료를 제시하기 위하여 배수용 geotextile을 대상으로 평면투수성능을 실험적으로 분석하였다. 일반적으로 압축응력의 증가에 대한 geotextile의 두께, 평면투수계수 및 전수성은 10KN/m2 정도 이하에서 현자한 감소를 보였으며 Geotextile의 평면투수계수는 장섬유부직포가 단섬유부직포나 복합포 보다 낮게 나타났다. 또한 Geotextile의 압축률은 PES. 계부직포가 PP계 부직포 보다 큰 경향을 보였으며 geotextile의 압축음력 e(KN In)와 압축률 Cr(oA)의 관계식은 Cr=13.37 In+23.28로 표시되었고 2KN In"를 기준 으로 한 압축률 Cr'와 평면 투수계수 감소율 Pr의 관계식은 Pr=1.250r'로 표시되었다.

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Magnetoimpedance Effect in Nanocrystalline Fe91.5-xZr7BxCu1Al0.5 (x=2, 4, 6, 8) Alloys

  • Lee, Heebok;Kim, Yong-Kook;Kim, Taik-Kee;Kim, Chong-Oh;Yu, Seong-Cho
    • Journal of Magnetics
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    • 제7권1호
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    • pp.21-23
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    • 2002
  • The magnetoimpedance of $Fe_{91.5-x}Zr_7B_xCu_1Al_{0.5}$alloys has been measured to investigate the influence of structural changes in the nanocrystallization process after thermal treatment. Annealing was performed at temperatures of $350^\circ{C}$, $450^\circ{C}$, and $550^\circ{C}$ for 1 hour in a vacuum. Ultra soft magnetic behavior was observed in the samples annealed at $550^\circ{C}$. The magnetoimpedance ratio and the longitudinal permeability ratio coincided with the softness of the magnetic properties of the thermally treated samples.

Temperature Dependence of The Magnetoimpedence Effect in Nanocrystalline $Fe_{84}Zr_7B_6Cu_1Al_2$ Alloy

  • Kwon, Hye-Suk;Lee, Heebok;Kim, Yong-Kook;Yoon, Sung-Ho;Kim, Taik-Kee;Yu, Seong-Cho
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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    • pp.473-479
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    • 2000
  • The nanocrystalline Fe$_{84}$Zr$_{7}$B$_{6}$Cu$_{1}$ $Al_{2}$ alloy was annealed at 450 $^{\circ}C$ and 550 $^{\circ}C$ for l hour to achieve the ultra-soft magnetic properties such as large magnetoimpedence ratio(MIR), the incremental permeability ratio(PR), nearly zero coercivity, zero magnetostriction, etc. The PR and MIR of the sample were measured from 100 kHz to 10 MHz at a cryogenic chamber where the temperature can be varie from 10 K to 300 K. The increment of MIR value is proportional to increasing temperature. The maximum PR values measured at high frequency above 1 MHz remain almost same despite of the temperature variation from 10 K to 300 K except the sharpness in PR curves. However, the maximum PR values measured below 1 MHz show drastic increment at above 150K due to thermal activation of magnetic domains.s.s.

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