3-D FEM analysis of the effects of SPT head dimensions on recording in discrete and continuous media

Due to the considerable increase of magnetic recording density, the deviation of the head from the centerline of the track becomes a serious problem for the cross-track interference. In this paper, a three-dimensional read/write simulation system was used to investigate the effect of the width of the write head on the behavior of the flux and magnetization for continuous track medium and discrete track medium. It is shown that the magnetization in a neighboring track of the discrete track medium is smaller than that of the continuous track medium. The output of the read head using the discrete track medium is larger than that of the continuous track medium when a suitable read head width is chosen so that the cross talk is negligible.</p

Magnetic shield design of perpendicular magnetic recording head by using topology optimization technique

It is necessary to develop a recording head having large recording field and small stray field to adjacent tracks and adjacent bits in perpendicular magnetic recording system. In this paper, in order to decrease the leakage flux in the adjacent bit, the approach of magnetic shield design of perpendicular magnetic recording head for 200 Gb/in/sup 2/ is performed by using the topology optimization technique.</p

Analysis of writing characteristics of CF-SPT head using 3-D read/write simulation system

Recently, the increase of areal recording density is remarkable. In order to develop a high density recording device, a read/write (R/W) simulation using three dimensional (3-D) magnetic field analysis is indispensable. In this paper, the magnetic field in a cusp-field single-pole-type (CF-SPT) head with discrete track media is analyzed using a 3-D R/W simulation system, in which edge-based finite element method and 3-D medium hysteresis model based on the ensemble of the Stoner-Wohlfarth (SW) particles are combined. The effects of ampereturns and the discrete track media on the distribution of recorded magnetization are investigated. The detailed behavior of flux around the discrete track media and continuous media is illustrated.</p

Urinary sludge caused by ceftriaxone in a young boy

It is known that ceftriaxone administration is associated with biliary pseudolithiasis, although the development of urolithiasis has been rarely reported. We encountered a young male with bacterial meningitis complicated by urinary precipitates composed of ceftriaxone-calcium salt which is confirmed by high-performance liquid chromatography. This patient suggested that ceftriaxone significantly increased urinary excretion of calcium, which may be linked to ceftriaxone-related urolithiasis or sludge. It is therefore worthwhile to monitor the levels of urinary calcium to creatinine ratio in patients on ceftriaxone, as they may be at greater risk for developing large stones and renal damage