We have computed the elastic constant tensor for PbZrTiOe, PZT 50/50, in the rhombohedral structure. We find it to be very soft elastically, and the Young's modulus to be very anisotropic. Our results for PZT are compared with literature values on other oxide perovskites, and the new experimental results on PMN-PT and PZN-PT. The elastic response is an important part of the electromechanical re...

Electromechanical devices are rapidly being miniaturized, following the trend in commercial transistor electronics. Miniature electromechanical devices--now with dimensions in the deep sub-micrometer range--are envisioned for a variety of applications as well as for accessing interesting regimes in fundamental physics. Among the most important technological challenges in the operation of these ...

The entire process of calibrating an electromechanical simulator – identifying relevant parameters, designing and measuring test structures, extracting parameters using detailed electromechanical simulations, and extrapolating the behavior of an actual device – is presented. The simulation model for electrostatically-actuated beams is calibrated to a wide range of electrical and optical test st...

Damping of the power system electromechanical oscillations with magnitude-phase excitation controller (MPH-EC), which is responsive to the deviations of the magnitude and phase of the terminal voltage phasor, and taking into account the finite speed of propagation the electromechanical waves, caused perturbation the power balance are considered in this paper. The structure of an integrated exci...

-Electromechanical wave propagation may affcet power system protective device operation. This paper discusses the testbed development to study the electromechanical wave propagation impacts on power system dynamic behavior, and consequently impacts on protective devices including overcurrent, distance, and out-of step relays. To have a better insight, a test bed to simulate electromechanical os...

This thesis describes the potential use of re-entrant microwave resonant three-dimensional cavities as low-loss electrical component in strongly coupled electromechanical systems. In particular , I have investigated radiative processes as a loss mechanism of a re-entrant cavity in a geometry similar to those used in electromechanical experiments undertaken by the Lehnert lab. First, I present t...

BACKGROUND Electromechanical wave imaging (EWI) is an entirely noninvasive, ultrasound-based imaging method capable of mapping the electromechanical activation sequence of the ventricles in vivo. Given the broad accessibility of ultrasound scanners in the clinic, the application of EWI could constitute a flexible surrogate for the 3-dimensional electrical activation. OBJECTIVE The purpose of ...

Electromechanical wave imaging (EWI) is an ultrasound-based technique that can non-invasively map the transmural electromechanical activation in all four cardiac chambers in vivo. The objective of this study was to determine the reproducibility and angle independence of EWI for the assessment of electromechanical activation during normal sinus rhythm (NSR) in healthy humans. Acquisitions were p...

BACKGROUND Osteochondral allograft transplantation has a good clinical outcome, however, there is still debate on optimization of allograft storage protocol. Storage temperature and nutrient medium composition are the most critical factors for sustained biological activity of grafts before implantation. In this study, we performed a time-dependent in vitro experiment to investigate the effect o...

energy harvesting from surrounding environment has been attractive for many researchers in recent years. therefore, developing appropriate test apparatus to study energy harvesting mechanisms and their performance is of paramount importance. due to their electromechanical characteristics, piezoelectric materials are used for harvesting energy from environmental vibrations. for optimum utilizati...