Results 151 to 160 of about 529,740 (187)

Reflection of impulses as a method of determining acoustic impedance

The Journal of the Acoustical Society of America, 1984
An impulse technique has been developed which allows investigation of the reflection of acoustic transients at different angles from an impedance boundary. From measurements of the direct and reflected impulses, the complex surface impedance has been calculated from the ratio of the corresponding Fourier components.
A. J. Cramond, C. G. Don
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Issues Concerning Determination of Impulse Voltage, Current, and Impedance

IEEE Electromagnetic Compatibility Magazine, 2021
The paper deals with satisfying the quasi-stationarity (or quasi-static) condition in studies of impulse quantities. The validity of the definition of voltage, current, and immittance is discussed. Examples are given regarding the electromagnetic compatibility issues when the quasi-stationarity condition is not met, thus the basic electric circuit ...
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An impulse method of measuring normal impedance at oblique incidence

Journal of Sound and Vibration, 1979
Abstract An experimental method of determining the oblique incidence behaviour of sound absorbing materials is given. The method involves the measurement of acoustic impulses at the surface of an absorbing material and comparing the complex frequency components with those of a reference signal recorded remote from the surface.
J.C. Davies, K.A. Mulholland
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Impulse response and radiation impedance of an annular piston

The Journal of the Acoustical Society of America, 1974
An approach is presented to evaluate the impulse response of an annular piston, which is mounted in an infinite planar rigid baffle. Since the impulse response is defined to be the time-dependent force on the ring, which results from an impulsive velocity of the ring, the impulse response and radiation impedance of the ring are a Fourier transform pair.
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Transient Impedance of High-Voltage Impulse Generating Systems

IEEE Transactions on Power Apparatus and Systems, 1970
The interaction between an impulse generating system and an impulse measuring system is dependent on the reflections that occur at the generator and divider ends of the measuring system lead. In this paper the impedances that cause these reflections are studied and discussed. The effects of the interactions are illustrated with sample oscillograms.
Frank Creed, Malcolm Collins
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An impulse voltage calibrator of low output impedance

IEEE Transactions on Power Delivery, 2005
A calibrator that produces full lightning impulses and chopped lightning impulses with variable chopping time is described. The calibrator uses series-connected power metal-oxide field-effect transistors as the main impulse switch and insulated gate bipolar transistors (IGBTs) as the chopping switch, and its output impedance is low to drive a ...
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Impulse Impedance Measurement Methodology in Space Restricted Locations

2019 International Symposium on Lightning Protection (XV SIPDA), 2019
This paper presents the analysis results of field measurements of ground resistance and impulse impedance. First, the Current Derivative Method is presented, whose objective is to obtain the RLF steady-state ground resistance value from the transient impedance curve $Z(t)$.
Adroaldo Raizer, Vilson Luiz Coelho, Thiago Schmoeller   +2 more
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Force-sensorless human joint impedance estimation utilizing impulsive force

Advanced Robotics, 2020
The paper is concerned with force-sensorless estimation of human joint impedance utilizing an impulsive force.
Keisuke Yagi, Yoshikazu Mori, Hiromi Mochiyama   +2 more
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Impulse Impedance Tests on Laboratory Model Earth Electrode

2005 Asia-Pacific Conference on Applied Electromagnetics, 2006
The investigation was carried out with the purpose of obtaining more information about electric discharges in sandy media. A cylindrical setup was chosen for impulse testing of earth rods to simulate the voltage gradients in the field when lightning propagates to earth rod.
N.A. Idris, H. Ahmad, M.N. Isa
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Variable Impedance Feed Structure for Impulse Radiating Antenna

2019 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2019
We present in this work, an alternative design for the TEM feeding structure of the Impulse Radiating Antenna (IRA). The variation here proposed consists of a set of TEM feeders whose impedance changes as a function of the radial distance measured from the focal point towards the parabolic reflector.
Felix Vega-Stavro, Fernando Albarracin-Vargas   +1 more
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