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1	Analytical investigation of internally resonant second harmonic lamb waves in nonlinear elastic isotropic plates Mueller, Martin Fritz 24 August 2009 (has links) This research deals with the second harmonic generation of Lamb waves in nonlinear elastic, homogeneous, isotropic plates. These waves find current applications in the field of ultrasonic, nondestructive testing and evaluation of materials. The second harmonic Lamb wave generation is investigated analytically in order to provide information on suitable excitation modes maximizing the second harmonic amplitude. Using an existing solution for the problem of second harmonic generation in wave guides, the solution is explained for the plate and examined as to the symmetry properties of the second harmonic wave, since published results are contradictory. It is shown that the cross-modal generation of a symmetric secondary mode by an antisymmetric primary mode is possible. Modes showing internal resonance, whose conditions are nonzero power flux from the primary wave and phase velocity matching, are shown to be most useful for measurements. In addition, group velocity matching is required. A material-independent analysis of the linear Lamb mode theory provides mode types satisfying all three requirements. Using the example of an aluminum plate, the found internally resonant modes are evaluated with regard to the rate of second harmonic generation and practical issues such as excitability and ease of measurement. Pros and cons of each mode type are presented. Group velocity matching Phase velocity matching Second harmonic generation Internally resonant Internal resonance Wave guide Lamb wave Nonlinear acoustics Ultrasonic waves Nondestructive testing Ultrasonic testing Lamb waves
2	Brillouin Propagation of Cold Atoms - Velocity-Matching or Mechanical Resonance? Scoggins, Casey Clark 05 August 2022 (has links) No description available. Optics Physics Brillouin brillouin propagation cold atoms optical lattice ratcheting directed ratcheting velocity matching velocity-matching velocity matching angled probe pump-probe spectroscopy off-axis probe mechanical resonance rubidium 85 dissipative bali samir casey scoggins brillouin feature angle error SAS spectroscopy
3	Control of physics-based fluid animation using a velocity-matching method Kim, Yootai 27 September 2006 (has links) No description available. Computer Science computer graphics computer animation fluid animation physics based animation fluid simulation smoke simulation smoke animation fluid animation control path based flow control linear feedback control velocity matching natural phenomena

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