Characterization of a cylindrical rod by inversion of acoustic scattering data

Ultrasonics ◽  
2014 ◽  
Vol 54 (6) ◽  
pp. 1559-1567 ◽  
Author(s):  
Mohammadreza Kari ◽  
Farhang Honarvar
Keyword(s):  
Acoustic Scattering ◽  
Scattering Data

Characterization of Cracks From Ultrasonic Scattering Data

1987 ◽  
Vol 54 (4) ◽  
pp. 754-760 ◽  
Author(s):  
J. D. Achenbach ◽  
D. A. Sotiropoulos ◽  
H. Zhu
Keyword(s):  
Scattered Field ◽  
Inverse Method ◽  
Crack Opening ◽  
Elastic Solid ◽  
Scattering Data ◽  
Crack Plane ◽  
Ultrasonic Scattering ◽  
Low Frequencies ◽  
Planar Crack

An inverse method for ultrasonic scattering data is proposed, to characterize a planar crack of general shape contained in an elastic solid. The method is based on an integral representation for the scattered field in the frequency domain. For a given scattered field the inverse problem has been formulated as a nonlinear optimization problem. At low frequencies its solution gives the location of the crack, the orientation of the crack-plane, and the crack-opening volumes. In addition the Mode I stress-intensity factor is obtained for a related static stress state corresponding to service loads.

Preparation and Characterization of Zn-Se Bilayer Structure

2007 ◽  
Vol 31 ◽  
pp. 153-157
Author(s):  
M. Singh ◽  
J.S. Arora ◽  
Kamlendra Awasthi ◽  
R. Nathawat ◽  
Y.K. Vijay
Keyword(s):  
Grain Size ◽  
Annealing Temperature ◽  
Hexagonal Structure ◽  
Scattering Data ◽  
Bilayer Structure ◽  
X Ray Diffraction ◽  
Thermal Evaporation Method ◽  
Rutherford Back Scattering ◽  
Back Scattering

The Zn-Se bilayer structure prepared using thermal evaporation method at pressure 10-5 Torr. These films annealed in the vacuum for two hours on different constant temperatures. The optical band gap was found to be varying with annealing temperature due to removal of defects and increase in grain size. It was also observed by the X-ray diffraction pattern the grain size of the film increase with annealing temperature. The lattice constant of hexagonal structure of these films is found to be a =b=4.42Å and c=5.68Å. The dominant peaks to be at 23.2°,28° and 43.9° having values (100), (002) and (111) respectively. The Rutherford back scattering data of these films confirmed the mixing of elements with time.

scholarly journals Chirality Characterization of Dispersed Single Wall Carbon Nanotubes

2005 ◽  
Vol 872 ◽  
Author(s):  
Min Namkung ◽  
Phillip A. Williams ◽  
Candis D. Mayweather ◽  
Buzz Wincheski ◽  
Cheol Park ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Optical Absorption ◽  
Raman Scattering ◽  
Scattering Data ◽  
Resonant Peak ◽  
Optical Absorption Spectroscopy ◽  
Single Wall Carbon Nanotubes ◽  
Sodium Dodecylbenzene Sulfonate ◽  
Single Wall Carbon

AbstractRaman scattering and optical absorption spectroscopy are used for the chirality characterization of HiPco single wall carbon nanotubes (SWNTs) dispersed in aqueous solution with the surfactant sodium dodecylbenzene sulfonate. Radial breathing mode (RBM) Raman peaks for semiconducting and metallic SWNTs are identified by directly comparing the Raman spectra with the Kataura plot. The SWNT diameters are calculated from these resonant peak positions. Next, a list of (n, m) pairs, yielding the SWNT diameters within a few percent of that obtained from each resonant peak position, is established. The interband transition energies for the list of SWNT (n, m) pairs are calculated based on the tight binding energy expression for each list of the (n, m) pairs, and the pairs yielding the closest values to the corresponding experimental optical absorption peaks are selected. The results reveal (1, 11), (4, 11), (5, 12), and (5, 9) among the most probable chiralities for the semiconducting nanotubes. The results also reveal that (4, 16), (6, 12) and (8, 8) are the most probable chiralities for the metallic nanotubes. Directly relating the Raman scattering data to the optical absorption spectra, the present method is considered the simplest technique currently available. Another advantage of this technique is the use of the, E11S, E33S, and E22M peaks in the optical absorption spectrum in the analysis to enhance the accuracy in the results.

scholarly journals Inference of biological and physical parameters in an internal wave using multiple-frequency, acoustic-scattering data

2003 ◽  
Vol 60 (5) ◽  
pp. 1033-1046 ◽  
Author(s):  
Joseph D. Warren ◽  
Timothy K. Stanton ◽  
Peter H. Wiebe ◽  
Harvey E. Seim
Keyword(s):  
Internal Wave ◽  
Field Experiments ◽  
Gulf Of Maine ◽  
Acoustic Scattering ◽  
Primary Source ◽  
Theoretical Work ◽  
Scattering Data ◽  
Physical Parameters ◽  
Multiple Frequency ◽  
Scattering Spectra

Abstract High-frequency sound (>10 kHz) is scattered in the ocean by many different processes. In the water column, marine organisms are often assumed to be the primary source of acoustic backscatter. Recent field experiments and theoretical work suggest that the temperature and salinity microstructure in some oceanic regions could cause acoustic scattering at levels comparable to that caused by marine life. Theoretical acoustic-scattering models predict that the scattering spectra for microstructure and organisms are distinguishable from each other over certain frequency ranges. A method that uses multiple-frequency acoustic data to exploit these differences has been developed, making it possible to discriminate between biological and physical sources of scattering under some conditions. This method has been applied to data collected in an internal wave in the Gulf of Maine. For regions of the internal wave in which the dominant source of scattering is either biological or physical in origin, it is possible to combine the acoustic-scattering data and temperature and salinity profiles with acoustic-scattering models to perform a least-squares inversion. Using this approach, it is possible to estimate the dissipation rate of turbulent kinetic energy for some regions of the internal wave, and the length and numerical abundance of the dominant biological scatterer, euphausiids, in others.

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