Fault strength evolution during high velocity friction experiments with slip-pulse and constant-velocity loading

abstract The mathematics for computing three-dimensional ray paths are developed for the case where medium consists of a series of constant-velocity layers separated by planes or spherical interfaces. These relations are used to investigate the cause of the LONGSHOT travel-time anomaly. The results of the investigation suggest that the anomaly could be caused by the presence of a thick slab of high-velocity material which dips steeply beneath the Aleutian arc and terminates at a depth of 300 km.

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CONSTANT VELOCITY JETS FOR QUANTITATIVE ULTRA-HIGH VELOCITY CRATERING STUDIES

10.21236/ad0462521 ◽

1965 ◽

Author(s):

Douglas H. Pack

Keyword(s):

High Velocity ◽

Constant Velocity

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Galactic orbits of stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900105340 ◽

1966 ◽

Vol 25 ◽

pp. 93-97

Author(s):

Richard Woolley

Keyword(s):

Globular Cluster ◽

Potential Field ◽

High Velocity ◽

Velocity Vector ◽

Variable Stars ◽

The Sun ◽

Proper Motions ◽

Rr Lyrae ◽

The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

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Supernovae and interstellar gas dynamics

Symposium - International Astronomical Union ◽

10.1017/s0074180900100774 ◽

1967 ◽

Vol 31 ◽

pp. 117-119

Author(s):

F. D. Kahn ◽

L. Woltjer

Keyword(s):

Lower Limit ◽

High Velocity ◽

Gas Dynamics ◽

Interstellar Cloud ◽

Interstellar Gas ◽

Random Motions ◽

Relativistic Particles

The efficiency of the transfer of energy from supernovae into interstellar cloud motions is investigated. A lower limit of about 0·002 is obtained, but values near 0·01 are more likely. Taking all uncertainties in the theory and observations into account, the energy per supernova, in the form of relativistic particles or high-velocity matter, needed to maintain the random motions in the interstellar gas is estimated as 1051·4±1ergs.

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Record Wear Studies by Scanning Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100101578 ◽

1968 ◽

Vol 26 ◽

pp. 364-365

Author(s):

M.D. Coutts ◽

E.R. Levin ◽

J.G. Woodward

Keyword(s):

Electron Microscopy ◽

Constant Velocity ◽

Peak Velocity ◽

Great Depth ◽

Depth Of Focus ◽

Sweep Frequency ◽

Transmission Electron ◽

Test Record ◽

Lateral Mode ◽

Scanning Electron

While record grooves have been studied by transmission electron microscopy with replica techniques, and by optical microscopy, the former are cumbersome and restricted and the latter limited by lack of depth of focus and resolution at higher magnification. With its great depth of focus and ease in specimen manipulation, the scanning electron microscope is admirably suited for record wear studies.A special RCA sweep frequency test record was used with both lateral and vertical modulation bands. The signal is a repetitive, constant-velocity sweep from 2 to 20 kHz having a duration and repetitive rate of approximately 0.1 sec. and a peak velocity of 5.5 cm/s.A series of different pickups and numbers of plays were used on vinyl records. One centimeter discs were then cut out, mounted and coated with 200 Å of gold to prevent charging during examination. Wear studies were made by taking micrographs of record grooves having 1, 10 and 50 plays with each stylus and comparing with typical “no-play” grooves. Fig. 1 shows unplayed grooves in a vinyl pressing with sweep-frequency modulation in the lateral mode.

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