• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.792-793
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• 2015

This paper present a general computation taking into account the slotting effect on the magnetic field due to permanent magnet in surface mounted permanent magnet machine. The analytical method is based on the solution of Laplace's and Poisson's equations (by the separation of variables technique) for each subdomain, i.e., magnets, air gap, and slots. The general solution is obtained using boundary and continuity conditions. The analytical results are in very good agreement with those obtained by the FEA, considering both amplitude and waveform.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.116.2-116.2
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• 2011

We investigate Faraday rotation measure (RM) toward high Galactic latitudes due to the Galactic magnetic field (GMF). The Galactic contribution to RM comes from the global component and the turbulent component of the GMF, and we newly model the latter by incorporating data of MHD turbulence simulations. We find that for the turbulent velocity of ~50 km/s, the standard deviation of the RM due to the GMF toward high Galactic latitudes is close to the observed value, several rad m^{-2}. Yet, the predicted second-order structure function (SF) has values substantially smaller than the observed ones at separation angles of <~ several degree. This suggests that the intergalactic magnetic field (IGMF) significantly contributes to RM toward high Galactic latitudes, particularly at small angular scales. Our work proposes a strategy for surveys to explore the IGMF with LOFAR, ASKAP, MeerKAT, and SKA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04a
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• pp.88-95
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• 2002

Recent development in the field of RE-Ba-Cu-O (REBCO, RE: Y or rare earth elements) bulk high-Tc superconductors (HTS) is reviewed in the present paper. After the fatal weak link problem of sintered REBCO superconductors has been overcome by melt processing, this field has been greatly advanced during last ten years. The critical current density $J_c$ at 77 K has been enhanced by introducing effective flux pinning sites into the $REBa_2Cu_3O_y$ (RE123) superconducting matrix. Large melt-textured REBCO bulk crystals have been fabricated with the TSMG(top-seeded melt growth) technique. Mechanical properties of REBCO bulks have been improved by using the Ag additive or epoxy resin. Real bulk applications such as current lead, fault current limiter, flywheel energy storage system, magnetic field source, magnetic separation system, and etc., surely come true near future.

• Journal of Ocean Engineering and Technology
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• v.20 no.2 s.69
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• pp.8-15
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• 2006

Guided-waves-based mortar-filled steel pipe inspection is carried out through using EMAT (Electro magnetic acoustic transducer) and wavelet transform. Possibly existing anomalies such as separation (or void) and inclusion are made in the fabricated mortar-fled steel pipes: these anomalies are infected. Since guided waves have the long range inspection capability, EMAT has its own advantages over the conventional PZT (Piezoelectric zirconate titanate), and wavelet transform gives the multi-resolution on time-frequency domain results, the suggested technique gives an alternative way for inspecting mortar-filled steel pipes, which are popularly used for supporting marine structures such as piers, wharfs, moles, and dolphins. Through this study, it is show that the suggested technique is promising for detecting the amounts of separations and inclusions.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.84-85
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• 2002

Recently doped perovskite manganites have renewed interest because they exhibit a variety of unique magnetic and electronic behaviors such as colossal magnetoresistance (CMR), percolative phase separation, spin/charge/orbital ordering, and so on. For this reason, fabrication of thin films with the best surface morphology and controlling their magneto transport properties is essential for making magneto-resistive devices. (omitted)

• Journal of the Korean Magnetic Resonance Society
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• v.6 no.2
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• pp.103-112
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• 2002

The photoproduced cation radical of N-methylphenothiazine $(PC_1)$ doped into phenyltriehtoxysilane (PhiTEOS), vinyltriethoxysilane (VTEOS) and methyltriethoxysilane (METOS) was studied with electron spin resonance (ESR) and electron nuclear double resonance (ENDOR). The photoinduced charge separation efficiency was determined by integration of ESR spectra which correspond to the amount of photoproduced cation radical in the matrices. This was correlatively studied with the polarity and pore size of the gel matrices. The relative polarity of the matrices was determined by measuring ${\lambda}_{max}$ values of $PC_1$ in the different matrices. The relative pore size among the matrices was determined by measuring relative proton matrix ENDOR line widths of the photoproduced cation of $PC_1$. The decay kinetic constants of the cation radical of $PC_1$ in the different matrices with relatively studied with fitting the biexponential decay curves after exposure at the ambient condition. This is correlatively interpreted with the polarity and pore size of the matrices.

• Bulletin of the Korean Chemical Society
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• v.18 no.4
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• pp.369-373
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• 1997

When 1H NMR spectra of pyridine, 4-amino-, 4-methyl-, and 4-cyanopyridine coordinated to the paramagnetic polyoxometalate, [SiW11CoⅡO39]6- in D2O are compared, both α- and β-proton peaks are shifted upfield as the basicity of the ligand decreases. The isotropic shifts are separated into contact and pseudocontact contributions by assuming that the contact shifts are proportional to the isotropic shifts of the same ligands coordinated to [SiW11NiⅡO39]6-. This separation reveals that the shift variations with the axial ligand basicity are dominated by changes in the magnetic anisotropy (pseudocontact shift) of [SiW11CoⅡ(ptl)O39]6- (ptl=pyridine-type ligand). The magnitude of the magnetic anisotropy in a series of pyridine-type ligands increases linearly as the pKa of their conjugate acids decreases.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.524-527
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• 1995

The temperature dependence of spin wave mode separation in amorphous $Co_{89.5}Zr_{10.5}$ thin film has been investigated at temperatures between 100 K and 300 K. The magnetization and the spectroscopic splitting factor were obtained for the main resonance mode in parallel and perpendicular magnetic field. ${\Delta}H_{2-3}$, the difference between resonance field of mode 2 and the resonance field of mode 3, increases with decreasing temperature. The linewidth increases for all the modes with decreasing temperature. Especially in mode 3 it increases rapidly below 200 K. This phenomenon could be caused by the increase of exchange stiffness constant or the decrease of surface magnetic anisotropy constant with decreasing temperature.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.833-834
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• 2001

A membrane immuno-chromatographic system that selectively separated plasma lipoproteins and generated a signal in proportion to the concentration of cholesterol within high-density lipoprotein (HDL) was investigated as a point-of-care device for the prognosis of coronary heart disease.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.717-720
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• 2003

A chromogenic biosensor employing microfluidics on a chip has been developed for the determination of high-density lipoprotein (HDL) cholesterol (HDL-C) in human serum. We have investigated a plain and effective method to immobilize enzymes within the microchip without chemically modifying micro-channel or technically micro-fabricating column reactor and fluid channel network. In assessing risk factors of coronary heart disease, a micro-chip system would minimize requirements of instrument and reagent handling.