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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, 2008Since 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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Mechanical Impedance Based Vibration Damping Test
SAE Technical Paper Series, 2017<div class="section abstract"><div class="htmlview paragraph">Traditionally, the damping performance of a visco-elastic material is measured using the Oberst bar damping test, where a steel bar is excited using a non-contacting transducer.
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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), 2002Discusses 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 +2 more
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Local Radiation Impedance of Vibrating Prolate Spheroids
The Journal of the Acoustical Society of America, 1972Prolate 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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SPIE Proceedings, 2009
This paper presents recent developments in an extremely compact, wireless impedance sensor node for combined use with both impedance method and low-frequency vibrational data acquisition. The sensor node, referred to as the WID3 (Wireless Impedance Device) integrates several components, including an impedance chip, a microcontroller for local ...
Stuart G. Taylor +6 more
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This paper presents recent developments in an extremely compact, wireless impedance sensor node for combined use with both impedance method and low-frequency vibrational data acquisition. The sensor node, referred to as the WID3 (Wireless Impedance Device) integrates several components, including an impedance chip, a microcontroller for local ...
Stuart G. Taylor +6 more
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Thin Vibrator with Variable Impedance in Rectangular Waveguide
2006 16th International Crimean Microwave and Telecommunication Technology, 2006The problem of scattering wave of type H10 by the thin vibrator with the variable surface impedance allocated in a rectangular waveguide is solved with the method of induced electromotive force.
M. Nesterenko, V. Katrich, E. Belogurov
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Impedance model for estimating train-induced building vibrations
Engineering Structures, 2018Abstract In recent years, the exploitation of over-track construction in populated Chinese cities has resulted in buildings being subjected to potentially disturbing vibrations from rail lines in metro depots. Building owners and engineers are concerned about occupants’ complaints related to structure-borne noise and vibration related to human ...
Chao Zou +3 more
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The Mechanical Impedance of Damped Vibrating Systems
The Journal of the Royal Aeronautical Society, 1941The 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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Series-parallel impedance structure for piezoelectric vibration damping
SPIE Proceedings, 2002This paper introduces a passive piezoelectric shunt controller, for damping multiple modes of a flexible structure using one piezoelectric transducer. The series-parallel impedance structure has a number of advantages over to previous techniques; it is simpler to implement, requires less passive elements and contains smaller inductors values.
Sam Behrens +2 more
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Acoustic input impedance of a vibrating cylindrical tube
Journal of Sound and Vibration, 2007An 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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