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Nonlinear Acoustic NDE Using Complete Nonclassical Spectra
AIP Conference Proceedings, 2006In the presence of cracked defects, material nonlinear response is determined by local contact dynamics which strongly depends on the amplitude of acoustic wave. At moderate driving amplitude, the contact acoustic nonlinearity suggests a fully deterministic scenario of higher harmonic generation and/or wave modulation.
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Estimation of sea surface spectra using acoustic tomography
The Journal of the Acoustical Society of America, 1989Ocean acoustic tomography signals that interact with the ocean surface suffer travel time perturbations which have information on the frequency-direction spectrum of that surface. In this paper, a technique for tomographically estimating spatially varying frequency-direction spectra is introduced. To demonstrate this technique, synthetic signal spectra
James H. Miller +2 more
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Acoustic phonon power spectra in a periodic superlattice
physica status solidi (b), 2006AbstractWe consider a Green function formalism, based on the frequency distribution, to study the propagation of acoustic phonon modes in a periodic superlattice. The calculations are based on the linear response function approach, which is very convenient to deal with this kind of problem.
P. W. Mauriz +2 more
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Concrete Material Response by Acoustic Spectra Analysis
Journal of the Structural Division, 1976The purpose of the research in this paper was to determine material behavior and strength characteristics of concrete materials, by studying stochastically the random-type acoustic emission patterns and intensities that emanate from concrete during loading.
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Naturally Enhanced Ion-Acoustic Spectra And Their Interpretation
Surveys in Geophysics, 2001Incoherent scatter radars are designed to detect scatter from thermalfluctuations in the ionosphere. These fluctuations contain, among other things,features associated with ion-acoustic waves driven by random motions within theplasma. The resulting spectra are generally broad and noisy, but neverthelessthe technique can, through a detailed analysis of ...
Francis Sedgemore-Schulthess +1 more
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Temporal characterization of flat-spectra natural acoustic transients
The Journal of the Acoustical Society of America, 1994Certain natural acoustic transients produce broad and relatively featureless spectra. Spectrographic analysis has revealed that rustling leaves, breaking sticks, and flowing water, which are likely to have shaped the evolution of the mammalian auditory system, are examples of this class of transients.
Frank Grasso, David C. Mountain
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Subharmonics Spectra of Acoustics Excitation in Granular Medium
AIP Conference Proceedings, 2008The results of experimental research of specific features of acoustical subharmonics excitation in granular medium are considered. It is founded that signal subharmonics registered at the scale of single granular extremely high varies in time and spectrum of this frequency component lies in some band.
Igor B. Esipov +5 more
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On acoustic turbulence spectra in a “dusty” plasma
Physics Letters A, 1994Abstract In a collisionless “dusty” plasma, where both ion-sound and dust-sound waves exist, the local spectra of isotropic sound turbulence are obtained. They are determined by decays of ion-sound waves into ion-sound and dust-sound waves and by scattering of dust-sound waves on dust particles.
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Resonant Acoustic Noise Spectra of Nucleate Coolant Boiling
Journal of Nuclear Science and Technology, 1974The detection of anomalous coolant boiling in non-boiling reactors is an important problem for assuring reactor safety. Acoustic techniques are an effective means of such detection. Reliable detection of boiling postulates frequency spectra peculiar to boiling, and if, moreover, the location of the boiling sites is to be determined, it should further ...
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Nonarbitrary regularization of acoustic spectra
Transport Theory and Statistical Physics, 1993Alexander N. Gorban, Iliya v. Karlin
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