摘要:
A system and associated methods are described for preparing a magnetic disk for installation within a disk drive system. For example, a polyfunctional lubricant may be mixed with a chemical agent to esterify the polyfunctional lubricant and cap hydroxyl groups of the polyfunctional lubricant. The magnetic disk may then be dip coated with the polyfunctional lubricant and chemical agent mixture. A polishing system then polishes the magnetic disk via an abrasive polishing tape after dip coating the magnetic disk. A portion of the chemical agent is then removed from the magnetic disk to bond a portion of the lubricant to the magnetic disk to prevent the lubricant from interfering with a read/write head when installed within a disk drive system.
摘要:
An improved disk drive system that employs a lubricant with improved charge control is provided. The disk drive system is comprised of a rotatably mounted magnetic disk. A rotor is coupled to the disk and rotatably retained by a stator. A bearing is formed that serves as an interface between the stator and the rotor. A motor coupled to the rotor rotates the magnetic disk via the rotor. Located in the bearing is a lubricant having a low relative electrical permittivity.
摘要:
A liquid/liquid extraction method is used for separating a perfluorinated polyether (PFPE) into two molecular-weight distributions using an alcohol or cyclic ether as one solvent and a fluorinated solvent as the other solvent. The more polar alcohol or cyclic ether solvent extracts the lower molecular weight PFPE and the less polar fluorinated solvent extracts the higher molecular weight PFPE. In addition, when the PFPE is a mixture of PFPEs with different end groups, such as a mixture of predominantly Z-Tetraol but with other PFPEs with Z-Dol end groups, there is an enrichment of the Z-Tetraol in the more polar solvent. The preferred PFPE is a mixture of PFPEs in as-purchased Z-Tetraol and the preferred solvents are methanol or trifluoroethanol as one solvent and a perfluorinated hydrocarbon, such as perfluorohexane, as the other solvent.
摘要:
A receiver used in a system having a transmitter (10) that sends an exciting signal to a remote transponder (18) is configured to receive a relatively weak signal from the transponder and to cancel out relatively high level interference from the transmission itself. A received frequency shift keying signal is fed to a tuned amplifier (22) for preliminary analog signal conditioning, and thence fed to an analog to digital converter (24). The output of the analog to digital converter is integrated (26) over a selected number of clock pulses and then dumped into a quarter rate quadrature demodulator (60) that multiplies the integrated signal by the same signal delayed by one clock interval. Undesired artifacts generated in the demodulator (60) are removed by a cascade of comb filters (70), and the demodulated digital output is available as the desired output of the receiver. The several clock signals of the system are all referenced from a basic exciter signal that itself gives rise to the transmitted interference signal so that the interference and all timing signals are approximately synchronous.
摘要:
A multiplying digital-to-analog converter for multiplying a bipolar input current by a digital word A having N bits a.sub.i including a current adder for adding a constant current to the bipolar input current to produce a unipolar current, a first current mirror responsive to the unipolar current for providing N binary weighted versions of the unipolar current, a second current mirror for providing binary weighted versions of the constant current, N current selection circuits respectively controlled the N bits a.sub.i for providing an output current comprising (a) the correspondingly weighted version of said unipolar current if the associated control bit is in a first state or (b) the correspondingly weighted version of the constant current if the associated control bit is in a second state, and a shifting circuit for summing the outputs of said N current selection means and for shifting the sum current to produce a bipolar output current representative of product of (a) the input bipolar current and (b) the digital word A.
摘要:
The adhesion of organic resins to substrate materials is increased by depositing on the substrate a coating of a plasma polymerized unsaturated organophosphine.
摘要:
A system and associated methods are described for preparing a magnetic disk for installation within a disk drive system. For example, a polyfunctional lubricant may be mixed with a chemical agent to esterify the polyfunctional lubricant and cap hydroxyl groups of the polyfunctional lubricant. The magnetic disk may then be dip coated with the polyfunctional lubricant and chemical agent mixture. A polishing system then polishes the magnetic disk via an abrasive polishing tape after dip coating the magnetic disk. A portion of the chemical agent is then removed from the magnetic disk to bond a portion of the lubricant to the magnetic disk to prevent the lubricant from interfering with a read/write head when installed within a disk drive system.
摘要:
The invention apparatus and method is practiced in large steam surface condensers and in one aspect comprises relatively narrow horizontal trays installed between the vertical tube bundles to drain the condensate from the upper bundle around the lower ones and thereby improve the heat transfer coefficient of the lower bundle(s). A second aspect of the invention apparatus comprises relatively narrow horizontal trays installed slightly below the lowest bundle to improve reheating of falling condensate up toward the saturation temperature of the condenser thereby reducing subcooling and the level of dissolved oxygen in that condensate. A third aspect of the invention apparatus comprises a partial hood retrofitted at the top of the central tubesheet air off-take entrance which is a unique element of the starburst/core pipe condenser design to thereby improve the air removal capability and consequently the performance of the condenser.
摘要:
Embodiments of the invention generally relate to PFPE lubricants, and more specifically to increasing the conductivity of PFPE lubricants. PFPE lubricants generally have low polarity and do not dissolve most conductive additives that tend to be highly polar. However, hydrophobic ionic liquids are highly fluorinated and have low polarity. Therefore, the hydrophobic ionic liquids may be dissolved in a PFPE lubricant to increase the conductivity of the PFPE lubricant.