Quasistatic Mechanics and Materials Stability of Particulate Media

1999 ◽  
Author(s):  
J. D. Goddard
Keyword(s):  
Particulate Media

Texture effects in particulate media

2005 ◽  
Vol 290-291 ◽  
pp. 498-501 ◽  
Author(s):  
M.A. Gonzalez-Fernandez ◽  
G. Blocksidge ◽  
C. Bunce ◽  
K. O’Grady ◽  
M. el-Hilo ◽  
...  
Keyword(s):  
Particulate Media

scholarly journals High-Density Recording Characteristics of the Obliquely Oriented Particulate Media

1994 ◽  
Vol 18 (S_1_PMRC_94_1) ◽  
pp. S1_443-446
Author(s):  
Shigeru SHIKAMA ◽  
Yuji SATOH ◽  
Mitsuhiro KATAOKA ◽  
Yoshitoshi SOUTOME ◽  
Hiroaki MORITA
Keyword(s):  
High Density ◽  
Particulate Media ◽  
High Density Recording

Noise and Recording Properties of Barium-Ferrite Particulate Media Studied by Micromagnetic Modeling

2011 ◽  
Vol 47 (2) ◽  
pp. 386-394 ◽  
Author(s):  
Pierre-Olivier Jubert ◽  
Brian Biskeborn ◽  
Diana Qiu ◽  
Ayako Matsumoto ◽  
Hitoshi Noguchi ◽  
...  
Keyword(s):  
Barium Ferrite ◽  
Particulate Media ◽  
Micromagnetic Modeling

Overcoats and Lubrication for Thin Film Disks

MRS Bulletin ◽  
1990 ◽  
Vol 15 (3) ◽  
pp. 45-52 ◽  
Author(s):  
A.M. Homola ◽  
C.M. Mate ◽  
G.B. Street
Keyword(s):  
Thin Film ◽  
Data Storage ◽  
Magnetic Particles ◽  
Areal Density ◽  
Magnetic Film ◽  
Alloy Thin Film ◽  
Magnetic Media ◽  
Disk Interface ◽  
Storage Devices ◽  
Particulate Media

Metallic alloy thin film media and ever decreasing head-to-media spacing make severe demands on storage devices. Decreasing head-to-media separation is critical for high storage densities but it also leads to increased slider-disk interactions, which can cause slider and disk wear or even head crashes. Wear can also occur when drives start and stop when the slider contacts the disk at relatively high speeds. The reliability and durability of thin film disks, which provide much higher areal density than conventional oxide disks with particulate media, are achieved by the use of very thin overcoat materials and surface lubricants. This article summarizes the approaches taken in the industry to enhance the tribological performance of magnetic media, with special emphasis on the basic understanding of the processes occurring at the slider-disk interface.The continuous rise in the demand for storage capacity at a competitive price is the prime motivator of the changes we have seen in the data storage industry. It is clearly stimulating the present move away from particulate media, which has long dominated all fields of data storage, i.e., tape, rigid, and flexible disks, to the thin film storage media. Particulate storage devices use magnetic media formulated by dispersing magnetic particles, usually iron oxides, in an organic binder. In thin film storage devices, the storage medium is a continuous magnetic film, usually a cobalt alloy, made either by sputtering or by electroless plating.

Microdeformations in Sands by Digital Image Processing and Analysis

1996 ◽  
Vol 1548 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Scott A. Raschke ◽  
Roman D. Hryciw ◽  
Gregory W. Donohoe
Keyword(s):  
Image Processing ◽  
Digital Image Processing ◽  
Digital Image ◽  
Small Scale ◽  
Two Dimensional ◽  
Localized Deformation ◽  
Displacement Fields ◽  
Particulate Media ◽  
Image Processing And Analysis ◽  
Video Images

Laboratory experiments are typically performed on particulate media to study stress-deformation behavior and to verify or calibrate computer models from controlled or measured boundary stresses and displacements. However, such data do not permit the formation of shear bands, displacement fields within flowing granular media, and other small-scale localized deformation phenomena to be identified. Described are two semiautomated computer vision techniques for accurately determining the two-dimensional displacement field in granular soils from video images obtained through a transparent planar viewing window. The techniques described are applicable for studying the behavior of particulate media under plane strain and certain axisymmetric test conditions. Digital image processing and analysis routines are used in two different computer programs, Tracker and Tracer, Tracker uses a graphical user interface that allows individual particles to be selected and tracked through a sequence of digital video images. A contrast edge detection algorithm delineates the two-dimensional projected boundaries of particles. The location of the centroid of each particle selected for tracking is determined from the boundary to quantify the trajectory of each particle. Tracer maps the trace or trajectory of specially dyed fluorescent particles in a sequence of video frames. A thresholding technique segments individual particle trajectories. Together, Tracker and Tracer provide a set of tools for identifying small-scale displacement fields in particulate assemblies deforming under either quasi-static or rapid loading (such as gravity flow).

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