Semi-analytical IGA-based computation of wave dispersion in fluid-coupled anisotropic poroelastic plates

2021 ◽  
Vol 212 ◽  
pp. 106830
Author(s):  
Fakhraddin Seyfaddini ◽  
H. Nguyen-Xuan ◽  
Vu-Hieu Nguyen
Keyword(s):  
Wave Dispersion

TO STUDY THE EFFECT OF BMV ON P WAVE DISPERSION AND SHORT TERM PROGNOSTIC IMPACT OF P WAVE DISPERSION IN PREDICTION OF CLINICAL OUTCOME AFTER PERCUTANEOUS BALLOON MITRAL VALVULOPLASTY IN PATIENTS WITH MITRAL STENOSIS AND SINUS RHYTHM

2020 ◽  
Vol 4 (9) ◽  
Author(s):  
Ashish Kumar Agarwal ◽  
Daulat Singh Meena ◽  
Vijay Pathak ◽  
Anoop Jain ◽  
Rakesh Kumar Ola
Keyword(s):  
Clinical Outcome ◽  
Right Ventricular ◽  
Wave Dispersion ◽  
Tissue Doppler ◽  
P Wave ◽  
Short Term ◽  
P Wave Dispersion ◽  
Mitral Valvuloplasty ◽  
Percutaneous Balloon ◽  
Before And After

Background: The aim of the present study was to study the effect of percutaneous balloon mitral  valvuloplasty (PBMV) on P wave dispersion and to test the correlation between P-maximum and  P-dispersion to right ventricular function and pulmonary artery pressure before and after PMBV. Also to study the impact of P-maximum and P-wave dispersion on the short term clinical outcome after successful PBMV in patients with mitral stenosis (MS) and sinus rhythm. Methods: 75 patients undergoing PMBV were enrolled in this study. We evaluated P-maximum, P-minimum and P-wave dispersion before and one month and one year after PBMV . We studied the changes in pulmonary arterial pressure (PAP), left atrial (LA) dimension, mitral diastolic gradient, and mitral valve area, in addition to the changes in right ventricular function utilizing tissue Doppler assessment both before and after PMBV, in addition the role of the P-wave dispersion in prediction of late cardiac events. Results: There were significant decrease in mean diastolic gradient, PAP, and LA size and significant improvement in right ventricular tissue Doppler indices after PMBV. Accompany these hemodynamic changes after PMBV. P-maximum and P-wave dispersion were found to be decreased (P < 0.001). Conclusion: Successful PBMV was associated with a decrease in Pmax and PWD. These simple electrocardiographic indices may predict the success of the procedure immediately after PBMV.  The P-maximum and P-wave dispersion changes were correlated with significant impairment of right dysfunction and the degree of pulmonary artery pressure. Keywords: PBMV.PAP,LA

Improved Surface Wave Dispersion Models, Amplitude Measurements and Azimuth Estimates

2005 ◽  
Author(s):  
Jeffry L. Stevens ◽  
David A. Adams ◽  
G. E. Baker ◽  
Mariana G. Eneva ◽  
Heming Xu
Keyword(s):  
Surface Wave ◽  
Wave Dispersion ◽  
Dispersion Models ◽  
Surface Wave Dispersion

scholarly journals Imaging the subsurface using induced seismicity and ambient noise: 3-D tomographic Monte Carlo joint inversion of earthquake body wave traveltimes and surface wave dispersion

2020 ◽  
Vol 222 (3) ◽  
pp. 1639-1655
Author(s):  
Xin Zhang ◽  
Corinna Roy ◽  
Andrew Curtis ◽  
Andy Nowacki ◽  
Brian Baptie
Keyword(s):  
Surface Wave ◽  
Ambient Noise ◽  
Velocity Structure ◽  
Joint Inversion ◽  
Body Wave ◽  
Source Parameters ◽  
Wave Dispersion ◽  
Inversion Method ◽  
Surface Wave Dispersion ◽  
Wave Data

SUMMARY Seismic body wave traveltime tomography and surface wave dispersion tomography have been used widely to characterize earthquakes and to study the subsurface structure of the Earth. Since these types of problem are often significantly non-linear and have non-unique solutions, Markov chain Monte Carlo methods have been used to find probabilistic solutions. Body and surface wave data are usually inverted separately to produce independent velocity models. However, body wave tomography is generally sensitive to structure around the subvolume in which earthquakes occur and produces limited resolution in the shallower Earth, whereas surface wave tomography is often sensitive to shallower structure. To better estimate subsurface properties, we therefore jointly invert for the seismic velocity structure and earthquake locations using body and surface wave data simultaneously. We apply the new joint inversion method to a mining site in the United Kingdom at which induced seismicity occurred and was recorded on a small local network of stations, and where ambient noise recordings are available from the same stations. The ambient noise is processed to obtain inter-receiver surface wave dispersion measurements which are inverted jointly with body wave arrival times from local earthquakes. The results show that by using both types of data, the earthquake source parameters and the velocity structure can be better constrained than in independent inversions. To further understand and interpret the results, we conduct synthetic tests to compare the results from body wave inversion and joint inversion. The results show that trade-offs between source parameters and velocities appear to bias results if only body wave data are used, but this issue is largely resolved by using the joint inversion method. Thus the use of ambient seismic noise and our fully non-linear inversion provides a valuable, improved method to image the subsurface velocity and seismicity.

GPR wave dispersion for material characterization

2021 ◽  
Vol 282 ◽  
pp. 122597
Author(s):  
Wallace W.L. Lai ◽  
Ray K.W. Chang ◽  
Christoph Völker ◽  
Bella W.Y. Cheung
Keyword(s):  
Material Characterization ◽  
Wave Dispersion

Inversion of Rayleigh wave dispersion curves via adaptive GA and nested DLS

2019 ◽  
Vol 218 (1) ◽  
pp. 547-559 ◽  
Author(s):  
Yuhang Lei ◽  
Hongyan Shen ◽  
Xinxin Li ◽  
Xin Wang ◽  
Qingchun Li
Keyword(s):  
Rayleigh Wave ◽  
Wave Dispersion ◽  
Dispersion Curves ◽  
Rayleigh Wave Dispersion

scholarly journals Nonlinear magneto-thermo-elastic vibration of mass sensor armchair carbon nanotube resting on an elastic substrate

2020 ◽  
Vol 7 (1) ◽  
pp. 153-165
Author(s):  
Rajendran Selvamani ◽  
M. Mahaveer Sree Jayan ◽  
Rossana Dimitri ◽  
Francesco Tornabene ◽  
Farzad Ebrahimi
Keyword(s):  
Carbon Nanotube ◽  
Mechanical Response ◽  
Scale Effects ◽  
Nonlocal Elasticity Theory ◽  
Wave Dispersion ◽  
Elastic Vibration ◽  
Ultrasonic Waves ◽  
Small Scale ◽  
Dimensionless Frequency ◽  
Mass Sensors

AbstractThe present paper aims at studying the nonlinear ultrasonic waves in a magneto-thermo-elastic armchair single-walled (SW) carbon nanotube (CNT) with mass sensors resting on a polymer substrate. The analytical formulation accounts for small scale effects based on the Eringen’s nonlocal elasticity theory. The mathematical model and its differential equations are solved theoretically in terms of dimensionless frequencies while assuming a nonlinear Winkler-Pasternak-type foundation. The solution is obtained by means of ultrasonic wave dispersion relations. A parametric work is carried out to check for the effect of the nonlocal scaling parameter, together with the magneto-mechanical loadings, the foundation parameters, the attached mass, boundary conditions and geometries, on the dimensionless frequency of nanotubes. The sensitivity of the mechanical response of nanotubes investigated herein, could be of great interest for design purposes in nano-engineering systems and devices.

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