Remanence coercivity of recording media in the high speed regime

1995 ◽  
Vol 31 (6) ◽  
pp. 2892-2894 ◽  
Author(s):  
L. He ◽  
D. Wang ◽  
W.D. Doyle
1996 ◽  
Vol 155 (1-3) ◽  
pp. 6-12 ◽  
Author(s):  
L. He ◽  
W.D. Doyle ◽  
L. Varga ◽  
H. Fujiwara ◽  
P.J. Flanders

2009 ◽  
Vol 1199 ◽  
Author(s):  
Yoshiomi Hiranaga ◽  
Kenkou Tanaka ◽  
Tomoya Uda ◽  
Yuichi Kurihashi ◽  
Yasuhiro Kimoto ◽  
...  

AbstractIn this study, we have developed ferroelectric data storage test systems based on scanning nonlinear dielectric microscopy (SNDM) to conduct various experiments concerning read/write capability. Nanodomain formation on ferroelectric recording media was studied using the data storage test system. A nanodomain dot array was successfully written on a single-crystal LiTaO3 recording medium. The diameter of the written dot was as small as 7 nm. Epitaxial-thin-film LiTaO3 recording media were also developed. Nanodomain dots with the diameter of 25 nm were written on the thin-film recording medium. In addition, a non-contact probe-height control technique was adopted to solve the problem of tip abrasion using higher-order nonlinear dielectric response detection method. Finally, a hard-disk-drive (HDD)-type ferroelectric data storage test system was developed for conducting read/write tests under conditions close to those of actual operation. Capabilities of reading at the bit rate of 2 Mbps and writing at the bit rate of 20 Mbps were confirmed using the HDD-type data storage test system.


1991 ◽  
Vol 44 (6) ◽  
pp. 255-305 ◽  
Author(s):  
Madeleine Coutanceau ◽  
Jean-Rene´ Defaye

The survey starts with the presentation of the general principles underlying the different types of techniques which are most often used in wake visualization with their advantages, but also their respective limits. Then information deduced from flow pictures collected from the literature from the beginning of the century up to the present has been used to characterize the wake structure of a circular cylinder (at rest or submitted to various motions) and its evolution with the Reynolds number for an extended range (0 < Re < 107). Incompressible flow has been more particularly considered, both in the quasi-established phase (ten regimes are differentiated and extensively described) and in the transient phase (specific features are pointed out). Special attention has been paid to three-dimensional and memory effects by a combined presentation of crosswise and spanwise observations of the wake phenomena as well as their evolution with time. The influence of compressibility in the high-speed regime and of superimposed periodic motions, either on the cylinder or on the stream, have been also investigated and the main characteristics of the lock-in regime have been described. The survey is illustrated by 40 figures and completed by a table in which are reported the successive studies related to the flow around a circular cylinder based upon visualization, including a brief account of the experimental setups and methods, as well as a description of the main phenomena observed in the corresponding pictures.


Author(s):  
W. D. Doyle ◽  
S. M. Stinnett ◽  
V. V. Konovalov

1998 ◽  
Vol 34 (2) ◽  
pp. 349-354 ◽  
Author(s):  
R.W. Chantrell ◽  
J.D. Hannay ◽  
M. Wongsam ◽  
A. Lyberatos

2019 ◽  
Author(s):  
Serguei Komissarov

We studied perfect carving turns of alpine skiing using the simple model of an inverted pendulum which is subject to the gravity force and the force mimicking the centrifugal force emerging in the turns. Depending on the turn speed the model describes two different regimes. In the subcritical ( low speed) regime, there exist three equilibrium positions of the pendulum where the total torque applied to the pendulum vanishes -- the marginally stable vertical position and two unstable tilted positions on both sides of the vertical. The tilted equilibria correspond to the ski turns executed in perfect balance. The vertical equilibrium corresponds to gliding down the fall line without turns. In the supercritical (high speed) regime, the tilted equilibria disappear. In addition to the equilibria the model allows fall-rise solutions, where the pendulum (skier) hits (rises from) the ground, and oscillations about the vertical. These oscillations correspond to the so-called dynamic skiing where the skier never settles to a balanced position in the turn. Analysis of the available data on FIS WC races shows that elite races ski mostly in the supercritical regime. In its current form the model of centrifugal pendulum has no feedback components associated with the skier control over their runs and therefore describes a riderless mono ski. Hence the theory predicts that such a vehicle can execute carving turns automatically.


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