In multilayer printed circuit boards, the noise on the power bus is influenced by the impedance between the power and ground planes. Power-bus noise estimates require an accurate estimate of the power-bus input impedance. This paper develops a closed-form estimate of the input impedance for circular power-return plane structures. When the structure is lossy (e.g., boards employing embedded capa...

Optimization methods based on input impedance target functions have been proposed for the design of brass musical instruments. Criteria for target functions in trombone bore optimization are discussed, drawing on experimental input impedance data from a variety of high-quality trombones of differing sizes. An "inharmonicity plot" is introduced and used to aid the interpretation of impedance cur...

Electromechanical (E/M) impedance method is emerging as an effective and powerful technique for structural health monitoring. The E/M impedance method utilizes as its main apparatus an impedance analyzer that reads the in-situ E/M impedance of piezoelectric wafer active sensors (PWAS) attached to the monitored structure. Laboratory-type impedance analyzers (e.g. HP4194) are bulky, heavy, and ex...

The effects of left stellate ganglion stimulation on pulmonary hydraulic input impedance was evaluated in 21 experiments on open-chest dogs anesthetized with chloralose. The stellate ganglion was stimulated at 1, 2, 5, 10, and 20 cps, and impedance spectra were generated at each frequency. Control spectra were characterized by frequency-dependent oscillations in impedance magnitude. Generally, ...

single-phase squirrel cage and three-phase induction electromotors are the most popular electromotors used in industry from long ago. when an induction motor starts with direct connection method, it takes a lot of current from the power supply (several times the nominal current); so, several methods have been devised to start such electromotors. these methods either reduce the voltage of the st...

normal 0 false false false en-us x-none ar-sa background: dry weight (dw) is an important concept related to patients undergoing hemodialysis. conventional method seems to be time consuming and operator dependent. bio impedance analysis (bia) is a new and simple method reported to be an accurate way for estimating dw. in this study, we aimed to compare the conventional estimation of dw with mea...

Because all microstrip antennas have to be matched to the standard generator impedance or load, the input impedance matching method for antenna is particularly important. In this paper a new methodology in achieving matching impedance of a planar microstrip antenna for wireless application is described. The method is based on embedding an Interdigital capacitor. The fine results obtained by usi...

The presence of multiple or diffuse lesions on imaging is a contraindication to surgery for patients with intractable epilepsy. Theoretically, as a functional imaging technique, electrical impedance tomography (EIT) can accurately image epileptic foci. However, most current studies are limited to examining epileptic spikes and few studies use EIT for real-time imaging of seizure activity. Moreo...

Recent implementations of virtual sound using head related transfer functions often include an analytical low frequency diffraction model to reproduce stable azimuth cues which are independent of the quality and accuracy of high frequency pinnae data. This paper investigates the previously neglected effects of surface acoustic impedance on the salient azimuth cues produced by a single sphere di...

A semi-empirical impedance model based on a single parameter (effective flow resistivity) for the characteristic impedance of fibrous materials has proved remarkably successful for predicting outdoor ground effects. This model allows for the effects associated with the porosity of the ground. Surface roughness with scales much smaller than the incident wavelengths influences reflection from har...