A simplified 5-RC transmission line equivalent circuit was introduced. Manganese dioxide cathodes from three commercial primary alkaline cells were investigated by means of ac impedance technique. Cathode Ohmic resistance, Faraday resistance for the reduction of MnO2, proton diffusion rate inside the lattice of EMD and electrochemical accessible surface area were obtained by numerical fitting o...

A variational method is given for determining the essential supremum of the surface impedance of a partially coated perfect conductor from a knowledge of the far field pattern of the time-harmonic electric field at fixed frequency. It is assumed that the shape of the scatterer has been determined (e.g., by solving the far field equation and using the linear sampling method). Numerical examples ...

The conducting polymer polypyrrole (PPy) was electrochemically grown on hydrogel scaffolds deposited on the surface of microfabricated neural prosthetic devices. It is shown that the pyrrole monomer can be grown vertically through the hydrogel layer up to the surface without affecting the adjacent sites on the probes. The electrochemical properties of the conducting polymer-modified hydrogels w...

We present details of an experimental method to measure the field modulated surface resistance (dR,/dH) of superconducting films accurately, which enables both field and temperature sweep experiments and is particularly useful for low-field or near T, measurements. The complex surface impedance Z,(H,T) =R,(H,T) + iX,(H, T) can also be simultaneously measured. This technique utilizes specially b...

The normal sound absorption coefficients of two different test objects in an impedance tube are measured with two different methods: The standing wave ratio method (ISO 10534-1:1996) and the transfer function method (ISO 10534-2:1998). From the latter is the specific acoustic impedance ratio calculated. The test objects are two cellular plastics: AC 30 S and FIRE 30 VF (both are 30 mm thick), t...

When the end-effector of a robot is slid on a flat surface, the stiffness matrix obtained by linear fitting of position and force contains information not only on the stiffness coefficient and on the normal direction, but also on the friction coefficient. This paper proposes a new method for extracting information on those properties from the stiffness matrix provided by the impedance perceptio...

Title of Document: DETECTION OF INTERCONNECT FAILURE PRECURSORS USING RF IMPEDANCE ANALYSIS Daeil Kwon, Doctor of Philosophy (Ph.D.), 2010 Directed By: Chair Professor and Director, Michael Pecht, Department of Mechanical Engineering Many failures in electronics result from the loss of electrical continuity of common board-level interconnects such as solder joints. Measurement methods based on ...

The dependence of complex impedance behaviour on mechanical surface treatment of glassy carbon electrodes in standard water KCl solutions at room temperature was investigated. A considerable frequency dependence of both the real and the imaginary term of the impedance was observed in the entire 1 5 0 kHz range of frequencies used for electrodes of different surface roughness. The results are di...

This paper analyzes the limits of applicability of the time domain surface impedance concept. Numerical results obtained by the boundary element formulation employing time domain surface impedance boundary conditions (SIBCs) of different orders of approximation are compared with experimental data and numerical results obtained using the finite element method. An analytical formula for evaluatio...

In this article, the following electrical impedance tomography problem (EIT) is considered: On the surface of a body with unknown impedance distribution, one applies a set of prescribed electric currents and measures the corresponding voltages on the surface. From this information, one seeks to estimate the internal structure of the body. Potential application areas of the EIT range from medica...