Results 141 to 150 of about 3,442 (182)

Impedance-matched vibration massager

The Journal of the Acoustical Society of America, 2009
A hand-held massager capable of self-excited, impedance-matched vibration for optimal massaging of each particular body part of each particular individual. The massager includes a hollow, open-ended contact piece to which is coupled a vibrator and which is to be held against a desired body part.
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System of impedance vibrators in anisotropic plasma

IEEE Antennas and Propagation Society International Symposium. 1998 Digest. Antennas: Gateways to the Global Network. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.98CH36194), 2002
Discusses research into linear antennas in anisotropic media. The purpose of the present work is to study the excitation of a system of thin impedance vibrators located in an anisotropic plasma, the permittivity tensor of which can contain not only positive, but also negative components.
N.A. Khizhnyak, N.M. Jatsenko, E.A. Jatsenko   +2 more
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Acoustic input impedance of a vibrating cylindrical tube

Journal of Sound and Vibration, 2007
An analytical approach to the acoustic input impedance of vibrating cylindrical pipes is considered. The variation in the acoustic impedance introduced by wall vibrations is calculated using the integro-modal method taking into account axisymmetric shell vibration. It is shown that this variation can be interpreted as a small correction in the acoustic
R. Picó, F. Gautier, J. Redondo
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The Mechanical Impedance of Damped Vibrating Systems

The Journal of the Royal Aeronautical Society, 1941
The concept of “mechanical impedance,” a quantity equivalent to Biot's Dynamic Modulus (reference i), has been utilised since 1939 by the de Havilland Aircraft Company as a standard method of treatment of vibration problems inengine airscrew systems, the method being applied principally to torsionalvibrations.
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Modal impedances for nonaxisymmetric vibrations of a thin spherical shell.

The Journal of the Acoustical Society of America, 1996
Modal impedances are found by solving the equations of motion of a thin spherical shell in terms of nonaxisymmetric modes of vibration. These mechanical impedances relate the modal expansion coefficients of the applied force per unit area and the velocity of the shell. The application and interpretation of these modal impedances require an awareness of
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Seismic Vibrator Impedance And Near-Surface Properties

EAGE Vibroseis Workshop - Vibroseis acquisition and processing half century later, new developments in data quality and productivity, 2008
Since the early days of Vibroseis, it has been observed that the vibrator behavior differs for different near-surface conditions. In its simplest form, the earth can be regarded as a spring, resulting in a baseplate motion that decreases with increasing earth stiffness (increasing spring constant). It was also observed that this simple spring model was
G. Baeten, F. Ernst
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Point Impedances Of Rectangular Plates And Vibration Isolation Of Machines

Journal of Sound and Vibration, 1993
Abstract The results of a theoretical investigation of point impedances at edges and in corners of thin isotropic and orthotropic plates are presented. These impedances for plates of reinforced concrete, steel and plywood were measured and compared with theoretical ones.
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Impedance spectroscopy of a vibrating wire for viscosity measurements

2010 IEEE Instrumentation & Measurement Technology Conference Proceedings, 2010
Many routine viscosity measurement systems suffer from low accuracy and some are also operator dependant which creates repeatability problems. This paper describes the ongoing developments of a viscosity measurement system based on a vibrating wire cell.
Fernando M. Janeiro, Pedro M. Ramos, Joao M.N.A. Fareleira, Joao C.F. Diogo, Dauria R.C. Maximo, Fernando J. P. Caetano   +5 more
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The effect of axial vibrations on the input impedance of the trumpet

The Journal of the Acoustical Society of America, 2019
It has been shown that the vibrations in the bell section of the trumpet can influence the sound produced by the instrument. Recent research has indicated that these effects may be traced the axial vibrations of the bell. We report experimental results that relate the input impedance of the trumpet to the phase of externally induced longitudinal motion.
Brooke Rodgers, Thomas Moore
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Local Radiation Impedance of Vibrating Prolate Spheroids

The Journal of the Acoustical Society of America, 1972
Prolate spheroidal coordinates and associated prolate spheroidal wave functions have been used to study the sound radiation from arbitrarily vibrating prolate spheroids. A local radiation impedance is defined and discussed. This impedance shows the effect of the strong locally variable nearfield and indicates that the spheroid generates L/2R (L/2R ...
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