Results 261 to 270 of about 32,369 (300)

Simple Impedance Test for Eustachian Tube Function

Archives of Otolaryngology - Head and Neck Surgery, 1981
A simple impedance method to evaluate Eustachian tube function has been reported. The principle of the test consists of recording the impedance of the eardrum during Valsalva's maneuver and during swallowing. By this procedure, the inflow and outflow of air through the tube is recorded as a simple pattern of impedance change that is classified into the
I, Honjo, T, Kumazawa, K, Honda
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Coupling Impedance of Cylindrical Tubes

IEEE Transactions on Electromagnetic Compatibility, 1972
The concept of a coupling (transfer) impedance as developed by Schelkunoff for cylindrical tubes is applied in the determination of the mutual coupling to a grounded coaxial cable. Formulas are developed utilizing the coupling impedance concept when the exciting, or interfering, circuit is either a single-wire line or another coaxial cable over a ...
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Comments on impedance tube measurements

The Journal of the Acoustical Society of America, 1981
The application of a new impedance measuring method to water-filled tubes is discussed. It is shown that source reflections do not invalidate the method, and that valid results can be obtained at frequencies several times higher than that of the first cross mode of the tube.
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Automation of impedance tube measurements

The Journal of the Acoustical Society of America, 1975
An apparatus is described that enables the automatic determination of impedance tube data, namely, the positions of the first two minima and the standing-wave ratios along the tube. Subject Classification: 85.20.
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Transverse Impedance of Two-Layer Tube

Proceedings of the 2005 Particle Accelerator Conference, 2006
The exact analytical expressions for the multipole longitudinal and transverse impedances of two-layer tube with finite wall thickness are obtained. The numerical examples for the impedances of the vacuum chamber with laminated walls are given.
M. Ivanyan, A.V. Tsakanian
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Acoustic Impedance Tube - Two-microphone method [PDF]

Absorption of sound by acoustic materials is a critical issue for acoustical engineering. Applications included sound isolation, improving acoustical quality of room and buildingdesign. Knowing the acoustic properties of materials is important for designing such applications.
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The validity of the linear orifice impedance model for predicting the impedance of a tube

The Journal of the Acoustical Society of America, 1992
The orifice impedance model usually works well for modeling sound transmission through an orifice. However, for a long orifice or for an orifice with a large load impedance, the standard impedance model may be invalid. The goal of this paper is to establish when the orifice impedance model gives a valid estimate of the impedance of a tube in series ...
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The impedance of the neon discharge in a conical tube

Journal of Communications Technology and Electronics, 2011
The frequency dependence of the impedance of the neon discharge in a conical tube is measured. The measured curves depend on the direction of the discharge current. For the interpretation of such variations, we comprehensively study the discharge in the conical tube for both directions of the discharge current.
A. K. Muradov, T. Kh. Guseinov
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A two-microphone thermoacoustic impedance tube

The Journal of the Acoustical Society of America, 2000
An experimental arrangement has been developed to explore the thermoacoustic properties of stack materials. The apparatus may be viewed either as a thermoacoustic engine with two microphones mounted in the tube wall, or as a two-microphone impedance tube that accommodates thermoacoustic elements.
Timothy Simmons, Richard Raspet, Robert Hiller   +2 more
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Small-Signal Impedance of Short Tubes

The Journal of the Acoustical Society of America, 1953
Relations expressing the acoustic inertance and resistance of short open tubes in terms of kva are reviewed. The tube radius is a; kv is the complex wave number for viscosity waves. Analogous relations giving the acoustical impedance of a cylindrical cavity in terms of kTa, where kT is the thermal wave number, are considered. Viscous and thermal losses
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