Perpendicular Magnetic Recording Media on Various Hard-Disk Substrates
Co-Cr perpendicular media on rigid substrates were studied. We used untextured glass substrates for perpendicular magnetic hard disks, but the reproduced output at short wavelengths was influenced by the surface roughness of the magnetic recording media. We therefore fabricated Co-Cr perpendicular hard disk media deposited onto different substrates: untextured glass, silicon single crystal, chemically textured alumite, and Mn-Zn ferrite. We compared these substrates with respect to their crystallographic properties, head-to-medium spacing, and record/playback characteristics.
PERPENDICULAR HARD DISK MEDIA FOR CONTACT SPT HEAD RECORDING SYSTEM
-A Co-Cr/Ni-Fe double layer hard disk medium for a new contact SPT head system was investigated in regard to its design. The medium was prepared with an RF sputtering system, sequentially depositing a Cr or a Ti underlayer, a soft-magnetic backlayer, a Co-Cr recording layer and a Si02 protective layer. The Cr underlayer with thickness of 0.025 f11n realized the most excellent crystallinity of the backlayer. The largest signal-to-noise ratio of 35 dB was obtained with thickness of 0.5 to 1.0 f11n for the Cu-MoPermalloy backlayer, and with about 2.0 f11n thickness for the Nb-Permalloy one, respectively. Addition of Ta to a Co-Cr system was also examined to narrow the anisotropy field distribution. It was found that a high output at high recording densities could be obtained for the narrowed ani.'IOtropy field distribution.
As práticas profissionais no campo público de atenção à saúde bucal: o caso de dois municípios da Bahia
This paper examines the working facilities and processes of dentists in the primary healthcare systems of two towns in Bahia State, Brazil, striving to analyze the extent to which factors related to dental care, training, placement and professional profiles influence their practices. Semi-structured interviews were conducted with nine dentists in both towns, with work process organization patterns in Municipality C being closer to the structuring principles of Brazil's National Health System than in Municipality E. This seems to be related to management characteristics, with networking links among individual, collective, and preventive clinical activities and planning noted in Municipality C. Despite these differences, the practitioners presented similarities in terms of dual militancy and perceptions of the public and private healthcare fields. The hegemony of the private sector seems to be influencing the professional practices of dentists in the public health system.