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Anand, R. S.
- Ultrasound Shock Wave Propagation and Generation of Harmonics in Biological Tissues
Abstract Views :219 |
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Authors
Affiliations
1 Electrical Engineering Department, IIT Roorkee, Roorkee-247667, IN
1 Electrical Engineering Department, IIT Roorkee, Roorkee-247667, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 33, No 4 (2011), Pagination: 77-87Abstract
In this paper, two theoretical methods for the description of nonlinear ultrasound wave generated from axis symmetric circular source and propagation in soft human tissues is described. Burgers’ equation has been used to model the nonlinear propagation of single sinusoidal wave of finite amplitude. In the first method, the analytical solution of Burgers’ equation was achieved by using Fubini method in preshock region while weak shock theory applied in postshock region for lossless medium. In case of lossy medium, the analytical solution of Burgers’ equation is achieved by using linear diffusion equation via Hopf-Cole transformation in preshock region and Fay’s equation in postshock region. In the second method the operator splitting methodology is implemented in which absorption term is solved using Crank Nicholson Finite Difference (CNFD) method in time and nonlinear term by using analytical method at each step for both lossless and lossy medium. Both the methods are solved in MATLAB. The results have been shown for waveform distortion and shock formation radiated by circular piston source for lossless and lossy tissue mediums. The analytical study of fundamental, second and third harmonic components variation along the distance of propagation has been done using both proposed methods and has been compared.Keywords
Nonlinear Wave, Ultrasonic Imaging, Burgers’ Equation, Shock Formation, Soft Tissues.- A Comparative Study of Prediction of Flaw Response and Flaw Detection in Polycrystalline Materials
Abstract Views :358 |
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Authors
Affiliations
1 Department of Electrical Engg, University BDT College of Engg, Davangere, IN
2 Department of Electrical Engg, Indian Institute of Technology, Roorkee, IN
3 Department of Mechanical and Industrial Engg, Indian Institute of Technology, Roorkee, IN
4 Naval Surface Warfare Center, Maryland, US
1 Department of Electrical Engg, University BDT College of Engg, Davangere, IN
2 Department of Electrical Engg, Indian Institute of Technology, Roorkee, IN
3 Department of Mechanical and Industrial Engg, Indian Institute of Technology, Roorkee, IN
4 Naval Surface Warfare Center, Maryland, US
Source
Journal of Pure and Applied Ultrasonics, Vol 33, No 1 (2011), Pagination: 8-15Abstract
The aim of this paper is to perform a comparative study of flaw response with the grain noise signal in an ultrasonic pulse echo simulation. This is one of the analytical methods to determine the flaw response. The flaw response is predicted using the approximation techniques like Kirchoff approximation, Born approximation and modified Born approximation. The grain noise signal generated in addition to flaw response is modelled analytically. By comparing the results of predicted flaw response and grain noise signal, the possibility of flaw detection can be estimated. Here the flaw considered for study is a spherical void and the material selected for study is a polycrystalline metal. Firstly, the comparison is made for 1 MHz circular transducer and secondly the study is performed for different center frequencies of transducer.Keywords
Spherical Void, Pulse Echo Simulation, Scattering Amplitude, Grain Noise Signal, Predicted Flaw Response.- Edge Preserved Enhancement of Ultrasound Medical Images Using Multiscale Ripplet Transform Based OGS Algorithm
Abstract Views :223 |
PDF Views:0
Authors
Affiliations
1 Department of Electrical Engineering, Indian Institute of Technology Roorkee, Roorkee-247667, U.P., IN
1 Department of Electrical Engineering, Indian Institute of Technology Roorkee, Roorkee-247667, U.P., IN