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Showing 1 to 8 of 8 for “"Nonlinearity parameter"”.
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Ultrasonic reflection mode imaging of the acoustic nonlinearity parameter
The problem of mathematically modeling the nonlinear interaction of ultrasound beams is addressed. The counterpropagation model is studied and a new model, called the copropagation reflection model, is proposed. The new model shows that the copropagation of the probe and the reflected pump leads to …
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Influences of biological structural features on the acoustic nonlinearity parameter B/A
… factors of biological media on the acoustic nonlinearity parameter B/A were studied at tissue, cellular and molecular levels, using both the thermodynamic method and the finite amplitude method. Experiments were designed to measure the B/A changes by altering structural factors of media …
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Continuous wave mode locking for the determination of the acoustic nonlinearity parameter B/A
The acoustic nonlinearity parameter B/A of the nonlinearity of the equation of state for a fluid. Its significance can be found in numerous fields including shockwaves, bio-chemistry and medicine. Recent studies in the field of biomedical ultrasound have necessitated a simple and accurate means of …
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Measurement of the Nonlinearity Parameter B/a in Biological Materials Using the Finite Amplitude and Thermodynamic Method
… in compressibility may be described by the nonlinearity parameter B/A. Organic liquids have been shown to possess a wide variation of the parameter, ranging from 5 to 12. This thesis reports on the measurement of this parameter in biological materials, including tissue models and soft …
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Design of a low pressure system to determine the acoustic nonlinearity parameter B/A for small volumes of sample liquids
… it can obtain measurements using relatively few parameters of the liquid, requiring only density and sound speed, and that it can obtain a result in a relatively short amount of time (less than 15 minutes after system has reached thermal equilibrium).
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Practical Aspects of Assessing Nonlinear Ultrasonic Response of Cyclically Load 7075-T6 Aluminum
… bicoherence spectrum are applied. The ultrasonic nonlinearity parameters by Cantrell and Jhang are introduced and presented as a function of the material fatigue growth, the number of fatigue cycles. This thesis presents the effectiveness of the bispectral analysis for evaluating the nonlinear …
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Acoustic metamaterials comprised of dead-end pores and black hole effect for low frequency sound absorption in linear and nonlinear regimes
… the linear regime, depending on the geometrical parameters. This model is complemented by a Transfer Matrix Model (TMM) and Finite Element Model (FEM) for both pancake and profile structures. The latter accounts for the influence of the structural resonances and tortuosity effect of the plates on …
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Characterization of nonlinearity parameters in an elastic material with quadratic nonlinearity with a complex wave field
… in an elastic half-space with a quadratic nonlinearity in its stress-strain relationship. Different boundary conditions on the surface are considered that result in both one- and two-dimensional wave propagation problems. The goal of the research is to examine the generation of second-order …