Results 241 to 250 of about 63,045 (293)
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Nonlinear ultrasonic attenuation in glasses
Journal of Non-Crystalline Solids, 1974Measurements of the attenuation of longitudinal sound waves of frequencies between 730 MHz and 1400 MHz were made on a borosilicate glass at temperatures from 0.4 K to 2 K. For high acoustic intensity J the absorption decreases with decreasing temperature.
W. Arnold +3 more
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Predictive simulation of nonlinear ultrasonics
SPIE Proceedings, 2012Most of the nonlinear ultrasonic studies to date have been experimental, but few theoretical predictive studies exist, especially for Lamb wave ultrasonic. Compared with nonlinear bulk waves and Rayleigh waves, nonlinear Lamb waves for structural health monitoring become more challenging due to their multi-mode dispersive features.
Yanfeng Shen, Victor Giurgiutiu
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Nonlinear explanation for bone-conducted ultrasonic hearing
Hearing Research, 2005Human listeners can perceive speech from a voice-modulated ultrasonic carrier presented via a bone-conduction stimulator. This study explored the psychoacoustic characteristics and underlying mechanisms of ultrasonic hearing by measuring difference limens for frequency (DLF) for pure tones modulated onto ultrasonic carriers.
Kiyoshi, Fujimoto +2 more
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Nonlinear Multibeam Ultrasonic Imaging
2008Studies were conducted on multi-frequency ultrasonic imaging to employ simultaneous transmission of 2 and 8 MHz pulses, where the secondary waves generated through nonlinear ultrasound propagation is utilized. Multi-frequency images are constructed by using various frequency components extracted from echo signals.
I. Akiyama +3 more
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Nonlinear ultrasonic imaging of imperfectly bonded interfaces
Ultrasonics, 2006A nonlinear ultrasonic imaging system is developed for detecting and imaging damages and defects with nm order gaps in industrial materials, which were undetectable by conventional ultrasonic imaging systems. A high power pulser generating large amplitude incident waves and high gain receiver with high-pass or band-pass filters extracting the second ...
Koichiro, Kawashima +5 more
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Nonlinear Ultrasonic Reciprocal Method for Damage Localisation
Structural Health Monitoring 2017, 2017Nonlinear ultrasonic techniques are based on the measurement of nonlinear elastic effects in the material, such as the magnitude of second harmonic response, in order to reveal the presence of surface and sub-surface flaws. These methods have shown to be more sensitive to damage-related structural alterations than any other ultrasonic technique, which ...
Boccardi S. +3 more
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SPICE Modeling Nonlinearity Effects on Ultrasonic Waves
Journal of Vibration and Acoustics, 2009Nonlinearity is one of the phenomena that affect the ultrasonic wave during its propagation in a given medium. In the time domain the nonlinearity is seen as a variation of the phase velocity which leads to a distortion of the waveform. This corresponds in the frequency domain to energy transfer from the fundamental frequency to the harmonic and among ...
Noureddine Aouzale +2 more
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Overview—Nonlinear Ultrasonic Characteristics
2020Nonlinear ultrasonic characteristics are the features that result from the nonlinear interactions between the propagating ultrasonic waves and the material or defects, which typically include higher harmonic generation, sub-harmonic generation, nonlinear resonance and nonlinear frequency-mixing.
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Micromachined structures for nonlinear ultrasonic transduction
2013 IEEE International Ultrasonics Symposium (IUS), 2013Recent studies have shown that ultrasonic propagation along chain-like structures can give very interesting properties. It is now known that non-linear propagation can take place along these chains, and this leads to some fascinating possibilities. This is because propagation is in the form of solitary waves.
Omololu Akanji +3 more
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2006
Abstract Up to this point, it has generally been assumed that the excitation is sufficiently small so that linearity can be assumed. In practice, for both ultrasound diagnostic and therapeutic applications, this condition is frequently exceeded. For diagnostic applications where a short, high-amplitude transmit pulse is used to obtain
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Abstract Up to this point, it has generally been assumed that the excitation is sufficiently small so that linearity can be assumed. In practice, for both ultrasound diagnostic and therapeutic applications, this condition is frequently exceeded. For diagnostic applications where a short, high-amplitude transmit pulse is used to obtain
openaire +1 more source