Abdel-Motaleb, Ibrahim Mohamed, 1954-
M.S. (Master of Science)
Department of Electrical Engineering
Image processing--Technological innovations; Ultrasonic imaging
This research is to utilize ultrasound waves and moire phenomena to establish a new imaging technology for industrial and medical applications. The theory and mathematical description is presented in this work. Numerical simulation is performed to prove the concept; COMSOL simulation, which uses finite difference technique, is used. The results are compared with experimental results done by a researcher from NIU at Santec Systems Inc., Wheeling, IL. The diffraction of the ultrasound waves is dependent on the wavelength. Because the sound wave length is large, a diffraction grating of wider pitch is used. Therefore, using ultrasound in shadow moire imaging will be limited by the size of pitch of the diffraction grating. Talbot image of the grating was studied using numerical simulation. The simulation results were found to be in agreement with experimental results. This is an evidence that ultrasound shadow moire has the same characteristics as light shadow moire. This work simulates the imaging of an inclined specimen with two different angles, 20 and 25 degrees. The distance between the first 2-moire fringes is found to be close to 5.5 mm. This means that the second fringe is a locus of constant out-of-plane elevation of 4.2mm with respect to the first fringe. This simulation provides an error compared with the experimental and theoretical results of 17.7%. This difference can be attributed to the fact that the experiments conditions are not ideal, and the use of paraxial and Fresnel approximation used in the analytical equations.
Yaqoub, Mahmoud, "Study of acoustic shadow moire for imaging technique" (2016). Graduate Research Theses & Dissertations. 5110.
viii, 49 pages
Northern Illinois University
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