scholarly journals Transition of gap-graded soil fabric – shear wave measurements and dispersion relation

2022 ◽  
Vol 62 (1) ◽  
pp. 101092
Author(s):  
Yang Li ◽  
Masahide Otsubo ◽  
Arian Ghaemi ◽  
Troyee Tanu Dutta ◽  
Reiko Kuwano
Keyword(s):  
Dispersion Relation ◽  
Shear Wave ◽  
Wave Measurements ◽  
Soil Fabric ◽  
Fabric Shear

Results Of Shear-Wave Measurements

1990 ◽  
Author(s):  
Wilfred P. Hasbrouck
Keyword(s):  
Shear Wave ◽  
Wave Measurements

scholarly journals Applying the cold plasma dispersion relation to whistler mode chorus waves: EMFISIS wave measurements from the Van Allen Probes

2015 ◽  
Vol 120 (2) ◽  
pp. 1144-1152 ◽  
Author(s):  
D. P. Hartley ◽  
Y. Chen ◽  
C. A. Kletzing ◽  
M. H. Denton ◽  
W. S. Kurth
Keyword(s):  
Dispersion Relation ◽  
Cold Plasma ◽  
Whistler Mode ◽  
Wave Measurements ◽  
Chorus Waves ◽  
Van Allen Probes ◽  
Plasma Dispersion

scholarly journals Shear Wave Measurements of a Gelatin’s Young’s Modulus

2020 ◽  
Vol 8 ◽  
Author(s):  
Stephen Pansino ◽  
Benoit Taisne
Keyword(s):  
Young’S Modulus ◽  
Shear Wave ◽  
Young's Modulus ◽  
Wave Measurements

Deep Shear Wave Velocity Profiles from Surface Wave Measurements in the Mississippi Embayment

2007 ◽  
Vol 23 (4) ◽  
pp. 791-808 ◽  
Author(s):  
Brent L. Rosenblad ◽  
Jianhua Li ◽  
Farn-Yuh Menq ◽  
Kenneth H. Stokoe
Keyword(s):  
Surface Wave ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Site Response ◽  
Source Surface ◽  
Mississippi Embayment ◽  
Near Surface ◽  
Wave Measurements ◽  
Central United States

Shear wave velocity ( VS) profiles to depths of approximately 200 m were developed from active-source surface wave velocity measurements in the Mississippi Embayment region of the Central United States. Soil deposits in this region are hundreds of meters thick, but are poorly characterized at depths below 60 m. Measurements were performed at five locations in Arkansas and Tennessee with a maximum distance between sites of approximately 130 km. The median VS profile calculated from the five profiles is in good agreement with a generic reference VS profile for the Mississippi Embayment that has been used in recent site response studies. The near-surface VS profiles at the five sites were remarkably consistent with average shear wave velocities in the top 30 m ( VS30), varying by less than 10%. Increasing variability between the VS profiles was observed at greater depths. The variability between VS profiles was shown to be correlated with changes in lithology at two of the sites where nearby lithologic information was available.

Shear Wave Measurements for Evaluation of Tendon Diseases

2016 ◽  
Vol 63 (11) ◽  
pp. 1906-1921 ◽  
Author(s):  
Chia-Lun Yeh ◽  
Po-Ling Kuo ◽  
Jean-Luc Gennisson ◽  
Javier Brum ◽  
Mickael Tanter ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Measurements

On the instability in second-order systems for acoustic VTI and TTI media

Geophysics ◽  
2012 ◽  
Vol 77 (5) ◽  
pp. T171-T186 ◽  
Author(s):  
Kenneth P. Bube ◽  
Tamas Nemeth ◽  
Joseph P. Stefani ◽  
Ray Ergas ◽  
Wei Liu ◽  
...  
Keyword(s):  
Wave Equation ◽  
Dispersion Relation ◽  
Differential Equations ◽  
Shear Wave ◽  
Transversely Isotropic ◽  
Second Order ◽  
Wave Speeds ◽  
Tti Media ◽  
Second Order Systems ◽  
Vti Media

We studied second-order wave propagation systems for vertical transversely isotropic (VTI) and tilted transversely isotropic (TTI) acoustic media with variable axes of symmetry that have their shear-wave speeds set to zero. Acoustic TTI systems are commonly used in reverse-time migration, but these second-order systems are susceptible to instablities appearing as nonphysical stationary noise growing linearly in time, particularly in variable-tilt TTI media. We found an explanation of the cause of this phenomenon. The instabilities are not caused only by the numerical schemes; they are inherent to the differential equations. These instabilities are present even in homogeneous VTI media. These instabilities are caused by zero wave speeds at a wide variety of wavenumbers — a direct consequence of setting the shear-wave speeds to zero — coupled with the second time derivative in these systems. Although the second-order isotropic wave equation allows smooth time-growing solutions, a larger class of time-growing solutions exists for the second-order acoustic TI systems, including nonsmooth solutions. Boundary conditions appear to be less effective in controlling these time-growing solutions than they are for the isotropic wave equation. These systems conserve an incomplete energy that does not prevent the instabilities. The corresponding steady-state systems are no longer elliptic differential equations and can have nonsmooth solutions that are related to the instabilities. We started initially with homogeneous VTI media, and then extended these results to heterogeneous variable-tilt TTI media. We also developed a second-order acoustic system for heterogeneous variable-tilt TTI media derived directly from the full-elastic system for heterogeneous variable-tilt TTI media. All second-order systems with a dispersion relation obtained by setting the shear-wave speeds to zero in the elastic dispersion relation allowed these nonphysical time-growing solutions; however, knowing the cause of these instabilities, it may be possible to prevent or control the activation of these solutions.

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