An attempt has been made to investigate the effect of SiO2 nanoparticles on the conductivity of polypyrrole conducting polymeric films prepared by an electrochemical method. The obtained nanocomposites were characterized by FTIR, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The results indicate that the conductivity of the nanoco...

Objectives To test the usefulness of continuous assessment of arterial load based on a 3-element Windkessel model by a combined analysis of the esophageal Doppler derived-blood flow and arterial pressure waveform, against standard frequency-domain analysis of arterial impedance. Methods Time-domain variables of arterial impedance were obtained by the simultaneous analysis of the Doppler derived...

To get clear the vibration mechanism of sandwith shell using experiment method, a double-layered plate is designed for sandwich by matching equivalent impedance. Numerical analysis conducted, and In 10Hz-4000Hz, differenceof impedance from should be less than 10%. A new design given plate, which quite simple construction. Then, could applied to conduct series tests influence core material on st...

Beneficial effects of nitroprusside infusion in heart failure are purportedly a result of decreased afterload through "impedance" reduction. To study the effect of nitroprusside on vascular factors that determine the total load opposing left ventricular ejection, the total aortic input impedance spectrum was examined in 12 patients with heart failure (cardiac index <2.0 liters/min per m(2) and ...

In many acoustic simulations, particularly when using lumped parameter models or electrical analog circuits, the acoustic impedance of a component needs to be determined accurately. A widely used acoustic impedance measurement method is the ”two microphone transfer function method”, which is standardized in ISO-10534-2. When the acoustic impedance is needed over a wide frequency band with a hig...

A generalized equivalent circuit model for waveguide transverse slots is proposed for the efficient analysis of waveguide transitions and waveguide slot antennas and slot-excited antennas. The transverse slots on the broad and end waveguide walls analyzed in this paper are decomposed into three structures: two apertures and an auxiliary waveguide section. The slot aperture in the host waveguide...

Abstract In the isolated island operation of microgrids, affected by different equivalent circuit impedance between distributed generators, traditional droop control cannot evenly divide reactive power borne generators according to line impedance. Therefore, firstly, reasons affecting sharing are analyzed, and then an improved method based on is proposed; that is, time change rate voltage used ...

An equivalent circuit model for predicting the frequency response of a square ring slot frequency selective surface (SRS-FSS) for normal incidence is described. The proposed FSS consists of an array of square patches centered within a wire grid. The presented circuit model is formed by the impedance of the wire grid that is parallel with the impedance of the patch array, also the mutual couplin...