Introduction  Eustachian tube (ET) dysfunction plays an important role not only in the pathophysiology of various middle ear disorders, but also in predicting the outcome of the treatment. As there is no single test that assesses both the anatomic and physiological functions of the ET, a combination of tympanometry and dynamic slow motion video endoscopy may improve the sensitivity of ET functi...

OBJECTIVE The present study aimed to investigate the vocal tract and glottal function during and after phonation into a tube and a stirring straw. METHODS A male classically trained singer was assessed. Computerized tomography (CT) was performed when the subject produced [a:] at comfortable speaking pitch, phonated into the resonance tube and when repeating [a:] after the exercise. Similar pr...

In this paper, an iterative method based on the transfer matrix approach was developed for evaluating sound speed and attenuation constant of air. If the air inside the impedance tube is treated as the tested material, such as porous materials, the transfer matrix approach can be easily used to identify the air’s acoustic properties. Then an iterative method can be applied in the post-processin...

Leiomyoma of the fallopian tube is extremely rare. Most cases are asymptomatic and found incidentally at autopsy or unrelated operation. These leiomyomas tend to be singular, small, and unilateral, with a resultant rare preoperative diagnosis. They are often managed with laparotomy, as seen in the literature review. Therefore, preoperative imaging is never reported. We describe a case of leiomy...

The effect of evanescent mode generation, due to geometrical mismatch, in acoustic impedance measurements is investigated. The particular geometry considered is that of a impedance probe with an annular flow port and a central microphone, but the techniques are applicable to other geometries. It is found that the imaginary part of the measured impedance error is proportional to frequency, and t...

This paper presents a methodology for the inverse characterization of sound absorbing rigid porous media, based on standard measurements of the surface acoustic impedance of a porous sample. The model parameters need to be normalized to have a robust identification procedure which fits the model-predicted impedance curves with the measured ones. Such a normalization provides a substitute set of...

Background: Impedance pump is a simple valveless pumping mechanism, which transports fluid through the mismatch of impedance in the system. Mismatch in impedance occurs when an asymmetrical periodic excitation is exerted on the elastic tube. Periodic asymmetrical excitation will then produce a unidirectional flow. Considering a multi-stage system with a single and constant power source, it is w...

The demand for 500 kV and 265 amperes peak to power an X-Band klystron brings up protection issues for klystron faults and the energy dumped into the arc from the modulator. This situation is made worse when more than one klystron will be driven from a single modulator, such as the existing schemes for running two and eight klystrons. High power pulsed klystrons have traditionally be powered by...