• 제목/요약/키워드: magnetics fields

검색결과 195건 처리시간 0.027초

Characteristics of HTS SQUID-based Susceptometer

  • Timofeev, V.P;Kim, C.G;Shnyrkov, V.I
    • Journal of Magnetics
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    • 제3권3호
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    • pp.82-85
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    • 1998
  • A portable HTS RF SQUID-based system, weighing less than 20 kg has been built for susceptometry applications in weak magnetic fields, It includes a YBCO sensor for measuring the axial magnetic field component with a resolution of about $7{\times}10^{-13} T/Hz^{1/2}.$ This is determined by the intrinsic magnetic noise in the quasi-white noise region. There is a relaxation for a sudden increase in field due to magnetic flux creep in HTS. In this instance the time did not exceed 3~5 minutes.

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Susceptometry Application of Portable HTS SQUID-Based System

  • Timofeev, V.P.;Kim, C.G.;Shnyrkov, V.I.
    • Journal of Magnetics
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    • 제3권3호
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    • pp.86-88
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    • 1998
  • A portable RF HTS SQUID-based susceptometer was used for small size magnetized sample testing in weak DC (up to 200A/m) and AC (up to 4 A/m) magnetic fields. The system resolution for the magnetic moment is of the order of $1.6{\times}10^{-10} A.m^2$. The measured DC susceptibility of a tested sample agrees well with the value obtained by using a commercial liquid helium susceptometer.

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COLLINEARITY AND SPIN FREEZING

  • Vincze, I.;Kemeny, T.
    • Journal of the Korean Magnetics Society
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    • 제5권5호
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    • pp.343-350
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    • 1995
  • An overview will be given on recent Mossbauer and magnetization investigation of the applied field dependence of the magnetic properties of typical systems without strong magnetic anisotropy and showing the absence of magnetic saturation in high fields (including iron-rich spin glass (amorphous $Fe_{93}Zr_{7}$, soft ferromagnets (amorphous $Fe_{88}Zr_{12}$, $Fe_{70}Ni_{20}Zr_{10}$ and $Fe_{88}B_{12}$) and pure Fe). The results emphasize that shape anisotropy due to surface irregularities causes misalignment between the magnetization and the applied field in the otherwise collinear magnetic structure.

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Pulsed Electromagnetic Fields to Influence Pain and Muscle Healing Following Muscle Injury in Rats

  • Koo, Hyun-Mo;Na, Sang-Su;Yong, Min-Sik
    • Journal of Magnetics
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    • 제20권4호
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    • pp.377-380
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    • 2015
  • Muscle contusion has a negative effect on muscle function. Although several studies showed that pain control and muscle recovery is facilitated by pulsed electromagnetic fields (PEMF), there has not been much research regarding the specific effects of PEMF on them. The aim of the present study is to investigate effects of PEMF on pain and muscle recovery following extensor digitorum longus (EDL) contusion injury through measuring the expression of the c-fos proto-oncogene and nerve growth factor (NGF). Significantly reduced c-fos expression in the spinal cord was shown in PEMF groups compared with control (CON) groups. There was no significant difference between PEMF1 and CON1, but significantly increased NGF expression was shown in PEMF3 and PEMF5 compared with in CON groups, where the numbers in the group names are the days from contusion. In conclusion, PEMF could be used to not only reduce pain in muscle injuries by down-regulating c-fos expression in the spinal cord, but it could also influence muscle healing through increasing NGF expression in the injured muscle.

Annealing Effect on Exchange Bias in NiFe/FeMn/CoFe Trilayer Thin Films

  • Kim, Ki-Yeon;Choi, Hyeok-Cheol;You, Chun-Yeol;Lee, Jeong-Soo
    • Journal of Magnetics
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    • 제13권3호
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    • pp.97-101
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    • 2008
  • We investigated the exchange bias fields at the NiFe/FeMn and FeMn/CoFe interfaces in 18.9-nm NiFe/15.0-nm FeMn/17.6-nm CoFe trilayer thin films as the annealing temperature was varied from room temperature to $250^{\circ}C$ in a vacuum for 1 hour in a magnetic field of 150 Oe. Interestingly, magnetic hysteresis (M-H) measurements showed that NiFe/FeMn/CoFe trilayer thin films exhibited a completely contrasting variation of the exchange bias fields at both the NiFe/FeMn and FeMn/CoFe interfaces with annealing temperatures. High-angle X-ray diffraction (XRD) measurements indicated the absence of any discernible effect of thermal treatment on the NiFe(111) and FeMn(111) peaks. The compositional depth profile obtained from X-ray photoelectron spectroscopy (XPS) results presented the asymmetric compositional depth profiles of the Mn and Fe atoms throughout the FeMn layer. We contend that this asymmetric compositional depth profile and the preferential Mn diffusion into the NiFe layer, compared to that into the CoFe layer, are conclusive experimental evidence of the contrasting variation of the exchange bias fields at two interfaces having a common polycrystalline FeMn(111) layer.

Application Technologies of Pulsed Power with the High Voltage and Current (고전압.대전류 pulsed power의 이용기술)

  • Lee, Hyeong-Ho;Kim, Young-Bae
    • Proceedings of the KIEE Conference
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    • 대한전기학회 1997년도 하계학술대회 논문집 E
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    • pp.1678-1680
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    • 1997
  • The pulsed power with the high voltage and current can be used to the fields of high speed pulses of energy in different forms such as electric current and voltage, electron beam, ion beam, x-rays, gamma rays, heat, magnetics fields, sound and shock waves. This paper is directed mainly at electrical engineers working on production and practical application of high speed pulsed power with high voltage and current.

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