scholarly journals Imaging the equilibrium state and magnetization dynamics of partially built hard disk write heads

2015 ◽  
Vol 106 (23) ◽  
pp. 232404 ◽  
Author(s):  
R. A. J. Valkass ◽  
W. Yu ◽  
L. R. Shelford ◽  
P. S. Keatley ◽  
T. H. J. Loughran ◽  
...  
Keyword(s):  
Equilibrium State ◽  
Hard Disk ◽  
Magnetization Dynamics ◽  
Write Heads

scholarly journals Time-resolved scanning Kerr microscopy of flux beam formation in hard disk write heads

2016 ◽  
Vol 119 (23) ◽  
pp. 233903 ◽  
Author(s):  
Robert A. J. Valkass ◽  
Timothy M. Spicer ◽  
Erick Burgos Parra ◽  
Robert J. Hicken ◽  
Muhammad A. Bashir ◽  
...  
Keyword(s):  
Hard Disk ◽  
Time Resolved ◽  
Write Heads ◽  
Beam Formation

Time resolved imaging of magnetization dynamics in hard disk writer yokes excited by bipolar current pulses

2014 ◽  
Vol 115 (17) ◽  
pp. 17B727 ◽  
Author(s):  
W. Yu ◽  
P. S. Keatley ◽  
R. J. Hicken ◽  
M. A. Gubbins ◽  
P. J. Czoschke ◽  
...  
Keyword(s):  
Hard Disk ◽  
Magnetization Dynamics ◽  
Time Resolved ◽  
Current Pulses ◽  
Time Resolved Imaging

Optimizing Vibration Isolation of Flex Circuits in Hard Disk Drives

2003 ◽  
Author(s):  
M. Brake ◽  
J. A. Wickert
Keyword(s):  
Vibration Isolation ◽  
Longitudinal Vibration ◽  
Hard Disk Drives ◽  
Experimental Studies ◽  
Hard Disk ◽  
Disk Drive ◽  
Vibration Modes ◽  
Disk Drives ◽  
Electronic Components ◽  
Write Heads

Flex circuits are a laminate of polyimide substrate, adhesive, and copper conductors, and they are used to connect the (stationary) electronic components in a hard disk drive to the (rotating) arm that positions the read/write heads above the disk. The transverse and longitudinal vibration of flex circuits couples with motion of the read/write heads and contributes to increased settling time and residual vibration following repositioning of the arm from one data track to another. In this paper, the results of parameter, optimization, and experimental studies are discussed with a view toward increasing the isolation of vibration between the flex circuit to the arm in terms of a metric involving one or several important vibration modes.

Optimizing Vibration Isolation of Flex Circuits in Hard Disk Drives

2004 ◽  
Vol 127 (2) ◽  
pp. 165-172 ◽  
Author(s):  
M. R. Brake ◽  
J. A. Wickert
Keyword(s):  
Vibration Isolation ◽  
Hard Disk Drives ◽  
Experimental Studies ◽  
Hard Disk ◽  
Disk Drive ◽  
Design Stage ◽  
Vibration Transmission ◽  
Write Heads ◽  
Vibration Coupling

A “flex circuit” is a laminate of polyimide substrate, adhesive, and copper conductors that is used to connect the stationary electronic components in a computer hard disk drive to the rotating arm that positions read/write heads above the disks. The flex circuit’s transverse and longitudinal vibrations couple with the arm, and those motions, although seemingly small, degrade performance during seek operations from one data track to another. The flex circuit and arm mechanism is defined by a number of geometric parameters, and some latitude is available at the design stage for choosing dimensions and angles so as to minimize vibration transmission from the flex circuit to the arm. In this paper, the results of parameter, optimization, and experimental studies are discussed with a view toward improving isolation of the arm from vibration of the flex circuit in one or several modes. Particularly for the mechanism’s odd modes, the flex circuit’s free length and the relative attachment angle between the arm’s centerline and the circuit can each be chosen to significantly reduce vibration transmission. A genetic algorithm was applied to minimize a metric of vibration coupling in several vibration modes, and, in the case study examined, vibration isolation was improved by over 80%.

Time resolved Kerr microscopy: Magnetization dynamics in thin film write heads

1999 ◽  
Vol 35 (2) ◽  
pp. 637-642 ◽  
Author(s):  
C.H. Back ◽  
J. Heidmann ◽  
J. McCord
Keyword(s):  
Thin Film ◽  
Magnetization Dynamics ◽  
Time Resolved ◽  
Write Heads

Magnetization dynamics of a flux control device fabricated in the write gap of a hard-disk-drive write head for high-density recording

2021 ◽  
Vol 129 (10) ◽  
pp. 103901
Author(s):  
Hirofumi Suto ◽  
Masayuki Takagishi ◽  
Naoyuki Narita ◽  
Hitoshi Iwasaki ◽  
Tazumi Nagasawa ◽  
...  
Keyword(s):  
Hard Disk Drive ◽  
Hard Disk ◽  
Disk Drive ◽  
Control Device ◽  
High Density ◽  
Magnetization Dynamics ◽  
Flux Control ◽  
High Density Recording

Effect of Coil Position on Magnetization Dynamics of Multilayered Hard Disk Writer Yokes

2013 ◽  
Vol 49 (7) ◽  
pp. 3741-3744 ◽  
Author(s):  
Wei Yu ◽  
Paul S. Keatley ◽  
Rob J. Hicken ◽  
Mark A. Gubbins ◽  
Peter J. Czoschke ◽  
...  
Keyword(s):  
Hard Disk ◽  
Magnetization Dynamics

New life for hard-disk write heads

2017 ◽  
Vol 12 (1) ◽  
pp. 5-6 ◽  
Author(s):  
H. Jonathon Mamin
Keyword(s):  
Hard Disk ◽  
Write Heads

A Hitherto Undescribed Naturally Occurring Plasma Antagonist of Activated Factor X Inhibitor (Antithrombin III)

1979 ◽  
Author(s):  
E. T. Yin ◽  
W. J. Salsgiver ◽  
O. Tangen
Keyword(s):  
Equilibrium State ◽  
Human Plasma ◽  
Antithrombin Iii ◽  
Circumstantial Evidence ◽  
Incubation Mixture ◽  
Factor X ◽  
Normal Human Plasma ◽  
Plasma Component ◽  
Naturally Occurring ◽  
Normal Human

Circumstantial evidence suggested that normal human plasma contained a substance regulating the neutralization of F.Xa by F.Xa inhibitor(XaI), (Yin et.al.,Adv.Exper. Med. & Biol., 52 : 239, 1975, Plenum Press, N.Y.).This plasma component has now been isolated and partially purified in our laboratory, and tentatively designated as “Anti-XaI”.In experiments employing purified components, when Anti-XaI was incubated at 37°C with F.Xa, Xal and heparin for two minutes at pH7.5, the amount of F.Xa inhibited was inversely proportional to the Anti-XaI concentration. But, when the F.Xa was replaced by thrombin in the incubation mixture, the neutralization of thrombin clotting activity was undisturbed.Anti-XaI was found to be neither PF3 nor PF4.These and other data strongly suggest that the “Antithrombin III pathway” is more complex than currently believed to be. In circulating blood an equilibrium state must exist between Anti-XaI and XaI.Under certain conditions when the Anti-XaI activity is predominant the rate of F.Xa neutralization bv XaI then becomes slower than the activation of prothrombin to thrombin by F.Xa.

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