The Characteristics of High‐Frequency Attenuation of Shear Waves in the Longmen Shan and Adjacent Regions

2016 ◽  
Vol 106 (5) ◽  
pp. 1979-1990 ◽  
Author(s):  
Lei Fu ◽  
Xiaojun Li
Keyword(s):  
High Frequency ◽  
Shear Waves

High Frequency Ultrasound, a Tool for Elastic Properties Measurement of Thin Films Fabricated on Silicon

2011 ◽  
Vol 324 ◽  
pp. 277-281 ◽  
Author(s):  
Pierre Campistron ◽  
Julien Carlier ◽  
Nadine Saad ◽  
Jamin Gao ◽  
Malika Toubal ◽  
...  
Keyword(s):  
Thin Films ◽  
Elastic Properties ◽  
High Frequency ◽  
Shear Waves ◽  
Thin Layers ◽  
Acoustic Properties ◽  
Frequency Range ◽  
Frequency Method ◽  
Longitudinal Waves

The main goal of this work is to develop an ultrasonic high frequency method for characterization of thin layers. The development of high frequency acoustic transducers for longitudinal waves and shear waves on silicon has enabeled the characterization of thin films deposited on this substrate. Three types of transducers have been achieved : (i) single crystal LiNbOSubscript text3 Y+163° for shear waves generation, and (ii) Y+36° for longitudinal waves, bonded and thinned on silicon substrate to achieve ultrasonic transducers in the frequency range 300-600 MHz ; (iii) thin films ZnO transducers were realized due to sputtering technologies working in the frequency range 1 GHz- 2.5 GHz. Using an inversion method and a network analyser which provide the scattering S11 parameter of the transducer versus the frequency we deduce the elastic properties of films deposited on the wafer surface. Thanks to these transducers the acoustic properties of thin films such as SU-8 based nanocomposites (doped with TiO2 , SrTiO3 or W nanoparticles) will be presented. In order to achieve mechanical impedance matching between silicon and water we control the mass of the embedded particles which provide a way to adjust the elastic properties of the characterized material. In another application an Indium metallic layer have been characterized in the high frequency range. We also use this method to characterize dielectric permittivity of the ZnO transducers.

Propagating high-frequency shear waves in simple fluids

2009 ◽  
Vol 21 (1) ◽  
pp. 013105 ◽  
Author(s):  
Carlos Colosqui ◽  
Hudong Chen ◽  
Xiaowen Shan ◽  
I. Staroselsky ◽  
Victor Yakhot
Keyword(s):  
High Frequency ◽  
Shear Waves ◽  
Simple Fluids

High Frequency Viscoelasticity of Carbon Black Filled Compounds

1996 ◽  
Vol 69 (5) ◽  
pp. 786-800 ◽  
Author(s):  
M. Gerspacher ◽  
C. P. O'Farrell ◽  
L. Nikiel ◽  
H. H. Yang ◽  
F. Le Méhauté
Keyword(s):  
Carbon Black ◽  
High Frequency ◽  
Dynamic Properties ◽  
Shear Waves ◽  
Crosslinking Density ◽  
Filler Loading ◽  
Wave Measurements ◽  
Rubber Compounds ◽  
Longitudinal And Shear Waves ◽  
Laboratory Tool

Abstract A high frequency viscoelasticity spectrometer, using the state-of-the-art ultrasonic technology, was constructed. The longitudinal and shear waves characteristics were measured in rubber compounds to obtain the attenuation coefficient, α, and sound velocity, v Preliminary results were obtained for a number of filled and unfilled polymers. The grade of carbon black used, filler loading, crosslinking density and filler dispersion were varied during the study. Temperature sweepS from −100°C to +60°C were also studied. It was found that the polymer type had a greater influence on α and v than did the grade of carbon black, loading or dispersion. The experimental data show that shear waves do not propagate in the rubbery state. Above the glass transition temperature, Tg, the longitudinal wave measurements could be sufficient to determine the high frequency dynamic properties of filled and unfilled polymers to characterize a tire tread compound. The temperature sweep measurements allowed the determination of the Tg of polymers at high frequency. It is proposed that the described method of measuring α and v be used as a laboratory tool for potential tire traction prediction.

scholarly journals Internal Cylinder Identification Based on Different Transmission of Longitudinal and Shear Ultrasonic Waves

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 723
Author(s):  
Wen-Bei Liu ◽  
Wen-Bo Yan ◽  
Huan Liu ◽  
Cheng-Guo Tong ◽  
Ya-Xian Fan ◽  
...  
Keyword(s):  
High Frequency ◽  
Visual Inspection ◽  
Shear Waves ◽  
Ultrasonic Waves ◽  
Transmission Characteristics ◽  
Internal Defects ◽  
Longitudinal And Shear Waves ◽  
Defect Area ◽  
Ultrasonic Techniques ◽  
The Difference

We have built a Fizeau fiber interferometer to investigate the internal cylindrical defects in an aluminum plate based on laser ultrasonic techniques. The ultrasound is excited in the plate by a Q-switched Nd:YAG laser. When the ultrasonic waves interact with the internal defects, the transmitted amplitudes of longitudinal and shear waves are different. The experimental results show that the difference in transmission amplitudes can be attributed to the high frequency damping of internal cylinders. When the scanning point is close to the internal defect, the longitudinal waves attenuate significantly in the whole defect area, and their amplitude is always smaller than that of shear waves. By comparing the transmitted amplitudes of longitudinal and shear waves at different scanning points, we can achieve a C scan image of the sample to realize the visual inspection of internal defects. Our system exhibits outstanding performance in detecting internal cylinders, which could be used not only in evaluating structure cracks but also in exploring ultrasonic transmission characteristics.

Assessment of errors induced by the anomalous dispersion of high frequency shear waves in rheometrical measurements on gelling systems

2004 ◽  
Vol 124 (1-3) ◽  
pp. 11-24 ◽  
Author(s):  
R.A. Jones ◽  
S. Ravji ◽  
K. Hawkins ◽  
A. Al-Hussany ◽  
P.R. Williams ◽  
...  
Keyword(s):  
High Frequency ◽  
Shear Waves ◽  
Anomalous Dispersion

The application of reflection seismology to the investigation of the geometry of near-surface units and faults in the Blake River Group, Abitibi Belt, Quebec

1992 ◽  
Vol 29 (9) ◽  
pp. 2038-2045 ◽  
Author(s):  
Erick Adam ◽  
Bernd Milkereit ◽  
Marianne Mareschal ◽  
Arthur E. Barnes ◽  
Claude Hubert ◽  
...  
Keyword(s):  
High Resolution ◽  
High Frequency ◽  
Seismic Reflection ◽  
Mineral Exploration ◽  
Shear Waves ◽  
Reflection Seismology ◽  
Frequency Content ◽  
Near Surface ◽  
Surface Geology ◽  
High Frequency Content

Reprocessing of part of a Lithoprobe high-resolution seismic reflection line across the southern part of the Abitibi Belt has improved the imaging of shallow reflections and allowed correlation of the data with surface geology. Enhancement of early reflections was accomplished by focusing on the high-frequency content of the data. This improved resolution of reflections at two-way traveltime as early as 0.3 s and attenuated noise such as shear waves. The shallow reflections are interpreted as impedance contrasts at the contact between a metadiabase–diorite body and metavolcanics rocks. Offsets of the reflectors correlate with faults mapped at the surface and indicate a downdropped block, which may be of interest for mineral exploration.

Attenuation of high-frequency shear waves in the crust: Measurements from New York State, South Africa, and southern California

1990 ◽  
Vol 95 (B11) ◽  
pp. 17441 ◽  
Author(s):  
Arthur Frankel ◽  
Art McGarr ◽  
John Bicknell ◽  
Jim Mori ◽  
Leonardo Seeber ◽  
...  
Keyword(s):  
South Africa ◽  
New York ◽  
High Frequency ◽  
Southern California ◽  
Shear Waves ◽  
New York State ◽  
York State
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