An alternative representation of a Green’s function for electric fields on surfaces of thin impedance vibrators is proposed. The representation can be applied in software packages for simulation of RF and microwave devices. Advantages of the approach were demonstrated by analyzing the wellknown problem of a thin symmetrical horizontal vibrator above a perfectly conducting plane. For a half-wave...

In this investigation, the acoustical impedance of an internal combustion engine is measured and simulated. The measurements are based on the two microphone transfer function method, which is described in the standard ISO/FDIS 10543-2. The method uses the transfer function between two microphones positioned on a waveguide connected to the impedance to be measured. Some improvements are proposed...

the paper describes an investigation about the application of the new multiple-impedance discontinuities model for optimizing profile diffuser barriers. the new multiple-impedance discontinuities model is much faster than the numerical method, thus it is used in an optimization process. the a-weighted insertion loss was used for the traffic noise spectrum. the result of optimization, which is d...

A two-microphone transfer function (TMTF) method is adapted to a numerical framework to compute the radiation and input impedances of three-dimensional vocal tracts of elliptical cross-section. In its simplest version, the TMTF method only requires measuring the acoustic pressure at two points in an impedance duct and the postprocessing of the corresponding transfer function. However, some cons...

A problem of the spherical antenna consisting of a thin radial monopole located on a perfectly conducting sphere is solved. The antenna is excited at the base by a voltage δ-generator. An approximate analytical solution of the integral equation for the current on a thin impedance vibrator was found by the method of successive iterations. The solution is physically correct for arbitrary dimensio...

measurement of the stroke volume and its changes over time can be very helpful for diagnosis of dysfunctions in the blood circulatory system and monitoring their treatments. impedance cardiography (icg) is a simple method of measuring the stroke volume based on changes in the instantaneous mean impedanceof the thorax. this method has received much attention in the last two decades because it is...

Impedance measurements on arrays of microelectrodes can provide information about the growth, motility, and physiology of cells growing on the electrodes. In this talk, we report recent results obtained for the growth of 3T3 mouse fibroblasts and HCT116 human cancer cells on gold electrodes approximately 0.4 mm in area. Cells produce a characteristic peak in the impedance change plotted as a fu...

As they are spread across almost all applications based on electrical circuits, frequency filters form one of the most complex issues on electronic devices. There exist a great number of different design methods based on various approaches. A large group of these filters is based on active components, namely amplifiers, that are equipped with the appropriate feedback to achieve the desired tran...

Corrosion detection can be modelled by the Laplace equation for an electric or a heat potential in a simply connected planar domain D with a homogeneous impedance boundary condition on a non-accessible part of the boundary ∂D. We consider the inverse problem to simultaneously recover the non-accessible part of the boundary and the impedance function from two pairs of Cauchy data on the accessib...

studies show that any complications including hemorrhage, lack of blood supply, lack of oxygen supply, and death of cells in a tissue, will have a clear effect on electrical properties of that tissue. thus, by measuring impedance of a set of tissues, potential problems of the damaged tissue may be found. since electrical impedance is closely related to the measuring frequency, obviously, every ...