La0.67 Ca0.33 MnO3 thin films were investigated using nanosecond duration electrical pulses. It was found that strong (up to 30 kV/cm) electric fields significantly reduces the resistance of the film and shifts the peak in resistance vs. temperature dependence to higher temperatures. The results are discussed using a model based on fast spin and charge system response to electric field action o...

A new two-dimensional version of the Kolmorogov-Smirnov test has been developed for the testing of data which has been placed in a two-dimensional array of bins. Monte Carlo testing has been used to derive the test statistics for 8 x 8, 16 x 16 and 32 x 32 arrays. The predicted probabilities for non-square arrays and arrays with intermediate numbers of elements are compared to the probabilities...

One of the most important advances in biomedical engineering has been the ability to inspect inside the body without opening it. In this sense, rheoencephalography (REG) is an electromedical technique used to assess the cerebral blood flow (CBF) by noninvasive electrical impedance methods, using electrodes attached to the scalp surface. This technique was first proposed by Polzer and Schuhfried...

Perovskite-structure-type sol-gel barium-strontium-titanate (BST) thin films with molar formula BaxSr1−xTiO3 (x = 0.5, 0.6, 0.7, and 0.8) have been successfully fabricated as Al/BST/Pt capacitors. In order to study the role of the grain size in the conduction mechanisms, we present atomic force microscopy (AFM) results. The impedance and the electric modulus of BaxSr1−xTiO3 thin films have been...

This study examines conductive noise in long distance cables in a subsea environment. The conductive noise was caused by impedance mismatch between cables and appeared in the form of transient voltages. In particular, it is important to analyze the characteristics of transient voltages for different subsea temperature changes. To analyze the transient voltages, the effects of L, R, and C for di...

Wireless power transfer (WPT) has attracted an ever increasing interest from both industry and academics over the past few years. Its applications vary from small power devices such as mobile phones and tablets to high power electric vehicles, and from small transfer distance of centimeters to large distance of tens of centimeters. In order to achieve a high efficiency WPT system, each circuit ...

Multi-frequency electrical impedance tomography (EIT) systems require stable voltage controlled current generators that will work over a wide frequency range and with a large variation in load impedance. In this paper we compare the performance of two commonly used designs: the first is a modified Howland circuit whilst the second is based on a current mirror. The output current and the output ...

An instrumental electrode model (IEM) capable of describing the performance of electrical impedance tomography (EIT) systems in the MHz frequency range has been proposed. Compared with the commonly used Complete Electrode Model (CEM), which assumes ideal front-end interfaces, the proposed model considers the effects of non-ideal components in the front-end circuits. This introduces an extra bou...

microgrids are nowadays used to produce electric energy with more efficiency and advantage. however, the use of microgrids presents some challenges. one of the main problems of the microgrids widely used in electrical power systems is the control of voltage, frequency and load sharing balance among inverter- based distributed generators (dgs) in islanded mode. droop method performance degrades ...

The three electromagnetic properties appearing in Maxwell’s equations are dielectric permittivity, electrical conductivity and magnetic permeability. The study of point diffractors in a homogeneous, isotropic, linear medium suggests the use of logarithms to describe the variations of electromagnetic properties in the earth. A small anomaly in electrical properties (permittivity and conductivity...