Results 21 to 30 of about 21,993 (294)

A Nonlinear Ultrasonic Modulation Method for Crack Detection in Turbine Blades

Aerospace, 2020
In modern gas turbines, efforts are being made to improve efficiency even further. This is achieved primarily by increasing the generated pressure ratio in the compressor and by increasing the turbine inlet temperature.
Frank Mevissen, Michele Meo
doaj   +1 more source

Bayesian Spectral Estimation Applied to Echo Signals from Nonlinear Ultrasound Scatterers [PDF]

, 2010
The understanding and exploitation of acoustic echo signals from nonlinear ultrasound scatterers is an active research area that aims to improve the sensitivity and specificity of diagnostic imaging.
James R. Hopgood, Sboros, Vassilis, Yan Yan, Vassilis Sboros, Hopgood, James R., James R. Hopgood (EURASIP Member), Sboros, Vassilis; id_orcid, Yan, Yan, James R Hopgood, Hopgood, James; id_orcid   +9 more
core   +1 more source

Modeling and Simulation of Parametric Nonlinear Focused Ultrasound in Three-Dimensional Bubbly Liquids with Axial Symmetry by a Finite-Element Model

Shock and Vibration, 2023
This paper presents the development of a numerical model able to track in time the behavior of nonlinear focused ultrasound when interacting with tiny gas bubbles in a liquid.
María Teresa Tejedor Sastre, Alexandre Leblanc, Antoine Lavie, Christian Vanhille   +3 more
doaj   +1 more source

Theoretical prediction of the scattering of spherical bubble clusters under ultrasonic excitation

Ultrasonics Sonochemistry, 2023
Due to the nonlinear vibration of ultrasound contrast agent bubbles, a nonlinear scattered sound field will be generated when bubbles are driven by ultrasound. A bubble cluster consists of numerous bubbles gathering in a spherical space.
Xin Xu, Menyang Gong, Xiaozhou Liu
doaj   +1 more source

A local defect resonance for linear and nonlinear ultrasonic thermography [PDF]

, 2014
An efficient wave-defect interaction is the key to a high thermal response of flaws in ultrasonic thermography. To selectively enhance defect vibrations a concept of local defect resonance is developed and applied to ultrasonic activation of defects ...
Solodov, I., Rahammer, M., Busse, G.
core   +1 more source

Monitoring trabecular bone microdamage using a dynamic acousto-elastic testing method [PDF]

, 2010
Dynamic acousto-elastic testing (DAET) is based on the coupling of a lowfrequency (LF) acoustic wave and high-frequency ultrasound (US) pulses (probing wave). It was developed to measure US viscoelastic and dissipative non-linearity in trabecular bone.
DEFONTAINE, Marielle, S Callé, S Guerard, MORESCHI, Hélène, GUÉRARD, Sandra, G Renaud, M Defontaine, CALLE, Samuel, MITTON, David, D Mitton, RENAUD, Guillaume, H Moreschi   +11 more
core   +1 more source

Modelling Nonlinear Ultrasound Propagation in Bone

AIP Conference Proceedings, 2006
Simulations have been carried out to assess the possibility for detecting the nonlinear properties of bone in vivo. We employed a time domain solution to the KZK equation to determine the nonlinear field generated by an unfocussed circular transducer in both cancellous and cortical bone.
Cleveland, R, Johnson, P, Muller, M, Talmant, M, Padilla, F, Laugier, P   +5 more
openaire   +2 more sources

Rendering volumetric haptic shapes in mid-air using ultrasound:Proceedings of ACM SIGGRAPH Asia 2014 [PDF]

, 2014
We present a method for creating three-dimensional haptic shapes in mid-air using focused ultrasound. This approach applies the principles of acoustic radiation force, whereby the non-linear effects of sound produce forces on the skin which are strong ...
Tom Carter (196826), Subramanian, Sriram, Seah, Sue Ann, Sriram Subramanian (832158), Benjamin Long (1886557), Long, Benjamin, Carter, Tom, Sue Ann Seah (16171625)   +7 more
core   +1 more source

Nonlinear response to ultrasound of encapsulated microbubbles [PDF]

Ultrasonics, 2012
The acoustic backscatter of encapsulated gas-filled microbubbles immersed in a weak compressible liquid and irradiated by ultrasound fields of moderate to high pressure amplitudes is investigated theoretically. The problem is formulated by considering, for the viscoelastic shell of finite thickness, an isotropic hyperelastic neo-Hookean model for the ...
openaire   +3 more sources

Feasibility of detecting change in backscattered energy of acoustic harmonics in locally heated tissues

International Journal of Hyperthermia, 2019
Purpose: A real-time noninvasive thermometry technique is required to estimate the temperature distribution during hyperthermia to monitor and control the treatment.
Borna Maraghechi, Michael C. Kolios, Jahan Tavakkoli   +2 more
doaj   +1 more source