Control of three phase inverters has been an important issue in recent years. This paper proposes active disturbance rejection control (ADRC) scheme for controlling three phase inverters. The main advantage of ADRC that motivated us for using this controller for inverter is that it is model independent.  This controller is used in a double loop structure including an inner current loop and oute...

An efficient procedure is presented for the evaluation of solid oxide fuel cell (SOFC) anode microstructure triple phase boundary length (TPBL). Triple phase boundary- the one that is common between three phases of the microstructure- has a great influence on the overall efficiency of SOFC because all electrochemical reactions of anode take place in its vicinity. Therefore, evaluation of TP...

Background: Observing the enhancing plaques in magnetic resonance imaging (MRI) is one of the most valuable diagnostic modalities in confirming the diagnosis of multiple sclerosis (MS), its recurrence and for better detection of active disease. Since active lesions discovery can improve designating diffusion in time diagnosis of MS and controlling disease activity, and there is not any definite...

A strategy to increase the robustness of active MR tracking of microcoils in low signal-to-noise ratio conditions was developed and tested. The method employs dephasing magnetic field gradient pulses that are applied orthogonal to the frequency-encoding gradient pulse used in conventional point-source MR tracking. In subsequent acquisitions, the orthogonal dephasing gradient pulse is rotated wh...

IT HAS BEEN CONSIDERED that the end-plate potential (e.p.p.) is generated by the brief ionic flux across the end-plate membrane and the later slowly declining phase of the e.p.p. is due to the dissipation of the charge along and across the muscle membrane. This consideration was supported by some authors. Kuffler (21) observed with a single nerve-muscle preparation that the later slowly decayin...

We discuss the problem of solar active longitudes from the viewpoint of dynamo theory. We start from a recent observational analysis of the problem undertaken by Berdyugina & Usoskin (2003, A&A, 405, 1121) and Usoskin et al. (2005, A&A, 441, 347) who demonstrated from a study of sunspot data that solar active longitudes rotate differentially, with a small but significant asynchrony between nort...

An active RFIC X-band phase shifter is implemented using IHP SiGe HBT 0.25 μm SGB25V technology with an improved vector sum method. The chip is formed by a three way Wilkinson power divider, three phase delays for 0-120-240 degrees, three similar RFIC LNAs and a final three way Wilkinson power combiner on the same chip and occupies an area of 4x1.8 mm2. The circuit provides both phase and ampli...

Vortices of unusual form (rotating straight lines), phase-rotors, are found to occur in an active medium. Transitions between phase-rotors and Archimedian spiral waves are studied. The role of the dispersion relation in vortex development is discussed. Rotating nonlinear waves in active media have been attracting attention of the researchers during several decades. Such waves are found to occur...

The Shunt Active Power Filter is a very essential tool to remove harmonic currents and to reimburse reactive power for nonlinear loads. The fundamental standard of process of a Shunt Active Power Filter is to introduce an appropriate non-sinusoidal current (compensating current) into the system at the point of common coupling. This research work focuses on the time-domain approach for three-pha...