Results 171 to 180 of about 44,850 (204)
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Impulse response and radiation impedance of an annular piston
The Journal of the Acoustical Society of America, 1974An 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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Effective impedance spectra for predicting rough sea effects on atmospheric impulsive sounds
The Journal of the Acoustical Society of America, 2005Two methods of calculating the effective impedance spectra of acoustically hard, randomly rough, two-dimensional surfaces valid for acoustic wavelengths large compared with the roughness scales have been explored. The first method uses the complex excess attenuation spectrum due to a point source above a rough boundary predicted by a boundary element ...
Patrice, Boulanger, Keith, Attenborough
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Coronary input impedance during cardiac cycle as determined by impulse response method
American Journal of Physiology-Heart and Circulatory Physiology, 1987The coronary arterial system was characterized by its input impedance determined in systole and diastole from impulse response functions in five dogs. The impulse response technique was verified on a known hydraulic system. A second confirmation was obtained on the circumflex artery: reflected pulses were correlated with site of reflections generated ...
G A, Van Huis, P, Sipkema, N, Westerhof
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Grid Impedance Frequency Response Measurements Using Pseudo-Random Impulse Sequence Perturbation
2019 9th International Conference on Power and Energy Systems (ICPES), 2019The frequency-domain properties of supply network impedance are of increasing importance for applications such as grid-connected inverters, especially with reference to aspects such as the harmonic distortion specifications associated with grid compliance criteria.
Fredrick M. Mwaniki +1 more
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Characterization of impedance boundary as damped harmonic oscillators via impulse reflection
The Journal of the Acoustical Society of America, 2006This paper demonstrates that various sound-absorbing/reflective materials or structures can be effectively characterized over a wide band of frequency by the sum of only a few damped harmonic oscillators. This method is physically sound in the sense that each damped harmonic oscillator corresponds to the natural resonance of the impedance boundary as ...
Fung, KY, Jing, X
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Impulse-degradation analysis of ZnO-based varistors by AC impedance measurements
Journal of Physics D: Applied Physics, 1991A new degradation analysis of ZnO-based varistors by AC impedance measurements is presented. From these measurements, which have been achieved on samples as a response to a small signal in the frequency range 10-3 to 105 Hz, at room temperature, the distribution function of the relaxation time constant has been deduced.
Ai Bui +4 more
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[Diurnal profile of impulse oscillometric impedance in healthy subjects].
Pneumologie (Stuttgart, Germany), 1997Diurnal profiles of impulse oscillometry during 24 hours in 3 hour intervals in sitting and lateral lying position have been studied in 20 healthy female and male probands 10-67 years of age. Approximating the profiles by a sine-cosine-function the amplitude of resistance was found up to 3, that of reactance up to 1 hPa/l/s in single cases, preferably ...
J, Vogel +4 more
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Research on Field Test of Impulse Grounding Impedance for Small Substation
2018 International Conference on Smart Grid and Electrical Automation (ICSGEA), 2018In this paper, application of a portable instrument to obtain impulse grounding impedance (IGI) characteristics for grounding grid of small substation is introduced. The test currents of 8/20 µs, 10/350 µs and 30/80 µs were chosen as the injection signal sources to the grounding grid respectively with simultaneous measurement of the response ...
Si Wen-Rong +5 more
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A High-Impedance, Nanosecond Rise Time Probe for Measuring High-Voltage Impulses
IEEE Transactions on Power Apparatus and Systems, 1968Normal voltage dividers for high-voltage impulses are connected to the test object by an open air line which, when considered as part of the measuring system, gives an initially low input impedance to that measuring system due to the characteristic impedance of the line.
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Integrative oncology: Addressing the global challenges of cancer prevention and treatment
Ca-A Cancer Journal for Clinicians, 2022Jun J Mao,, Msce +2 more
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