Results 261 to 270 of about 1,246,575 (309)
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Acoustic phonon spectra of FeCl2
Solid State Communications, 1974Abstract The acoustic phonon dispersion curves for FeCl2 at room temperature have been measured by inelastic neutron scattering. The slope of the TA (ζ00) e ‖ z branch, 1650 m sec , is found to be close to that proposed by Laurence and Petitgrand (1500 m sec ) to explain the drop in the low temperature thermal conductivity due to ...
W.B. Yelon, R. Scherm, C. Vettier
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Electroacoustic contingency management of the acoustic spectra of speech
Journal of Communication Disorders, 1975Three studies involving the manipulation of the acoustic spectrum of speech are described. An array of electronic equipment was set up which signaled the presence or absence of certain frequency characteristics of speech. Subjects (Ss) were given feedback for production of speech containing targeted frequencies.
Fitch, James L., Terrio, Leelen M.
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Spectra of laser acoustic signals in water
2011 International Conference on Electric Information and Control Engineering, 2011To get the spectra of laser acoustic signal (LAS) in water induced by CO2 laser pulse, and the relation to the parameters of laser pulse (LP). A peak-tail approximation of the actual CO2 LP is used to get the theoretical thermoelastic LAS, after FFT(Fast Fourier Transformation), the affection of the waveform parameters to the LAS spectra is given.
Chen Qingming, Cheng Zuhai, Zhu Haihong
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Amplitude spectra of acoustic pulses in the ocean
The Journal of the Acoustical Society of America, 1973An acoustic pulse propagating the ocean encounters weak thermal patches that scatter energy. If these patches are moving with a mean current perpendicular to the direction of propagation, a temporal fluctuation in the pulse-averaged amplitude occurs. This study calculates the temporal frequency spectrum of the pulse-to-pulse amplitude fluctuations and ...
Edmund H. Brown, Steven F. Clifford
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Interlaboratory comparisons of acoustic emission spectra
NDT International, 1980Abstract A procedure has been developed whereby acoustic emission frequency spectra can be corrected for the variable effects of specimen geometry, couplant, and transducer characteristics. The results of several experiments on 7039 Al show that quantitative agreement can be obtained between laboratories for the spectral shapes and amplitudes of ...
S.J. Acquaviva +9 more
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Electromagnetic and Acoustic Emission Fine Spectra
Advanced Materials Research, 2006A new measuring method for the detection of fine spectra of electromagnetic and acoustic emission (EME and AE) signals from small cracks is described. It requires wide band ultra-low noise amplifiers, analogue filters, the optimization of signal to noise ratio of sensors and the application of noise elimination methods.
Josef Sikula +3 more
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Information Content of Acoustic Attenuation Spectra
Particle & Particle Systems Characterization, 2002In recent years ultrasonic attenuation spectroscopy has gained much attention as a method for the characterisation of concentrated dispersions. Several publications have shown, that this method allows the accurate determination of particle size. In particular for submicron dispersions there is, however, some uncertainty to which degree the details of a
Frank Babick, Siegfried Ripperger
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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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Acoustical determinations of bubble-size spectra
The Journal of the Acoustical Society of America, 1977The exact integration of the equations for acoustical cross sections of bubbles is considered to show when the dependence of the bubble number on radius can be determined by scatter and attenuation experiments in a liquid containing a broad spectrum of bubble radii.
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Identification of acoustic spectra for fault detection in induction motors
2013 Africon, 2013In this paper, we study fault detection problem for induction motors by using a recently developed cross-power spectral density estimation algorithm from sound measurements. In a test rig, from multiple experiments the sound data were collected by an array of five-microphones placed hemispherically around motors in a reverberant and noisy room.
Hüseyin Akçay, Emin Germen
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