The purpose of this study was to determine the prevalence of developmental dental anomalies in an Indian population and to statistically analyze the distribution of these anomalies. The study was based on clinical examination, evaluation of dental casts, and panoramic radiographs of 1123 Indian subjects (572 males, 551 females), who visited the outpatient clinic at Government Dental College, In...

D ENTIN DYSPLASIA was first reported in 1922 by Ballschmiedel who described six children in one family whose teeth had short, blunted roots with pulpal occlusion that he called “rootless teeth.” Rushton2 later described a similar condition in an individual without evidence of genetic inheritance that he labeled “dental dysplasia. ” Cases have been reported in the literature that describe dentin...

Active Magnetic Bearings (AMBs) are already widely used in rotating machinery and continue to gain popularity due to the ever-present push to higher rotational speeds and decreasing prices of associated electronic components. They offer several advantages over conventional mechanical bearings including non-contact rotor support (thus eliminating mechanical wear and the need for lubricants), abi...

A three dimensions Hall probe has be manufactured for characterizing the magnetic performance of Cryogenic Permanent Magnet Undulator (CPMU) of Chinese High Energy Photon Source (HEPS) at Institute of High Energy Physics (IHEP). The positional and angular misalignment errors of the Hall sensors play an important role in the measurement accuracy of CPMU. In order to minimize the misalignment err...

This paper proposes an optimized model and control strategy for variable speed wind turbine using permanent magnet synchronous generator (PMSG). Models and equations that describe different components of the wind energy conversion system (WECS) are addressed and their implementations into PSCAD/EMTDC are described. There are different types of synchronous generators, but the PMSG is chosen. It ...

The back emf harmonics of a permanent magnet (PM) synchronous motor is a major source of torque ripple. For torque control applications including column fitted MDPS (motor driven power steering) systems, it is essential to reduce the mechanical vibrations due to torque ripples at low speeds. In this paper, a torque ripple reduction algorithm for interior PM synchronous motors is proposed. The h...

This paper is addressed to readers without advanced knowledge of remote sensing. It illustrates some current and potential uses of satellite Synthetic Aperture Radar interferometry (InSAR) for landslide assessment. Data acquired by SAR systems can provide 3D terrain models and be used to assist in regional scale investigations, e.g. aimed at evaluation of susceptibility of slopes to failure. Un...

A general pattern, which can include different types of permanent magnet (PM) arrangement in PM synchronous motors (PMSMs) is presented. By varying the geometric parameters of the general pattern, the template can automatically produce different types of PM arrangement in the rotor. By choosing the best arrangement of PMs using optimization method, one can obtain a better performance and lower ...

Since the air-gap field of flux-switching permanent magnet (FSPM) machines is difficult to regulate as it is produced by the stator-magnets alone, a type of hybrid-excited flux-switching (HEFS) machine is obtained by reducing the magnet length of an original FSPM machine and introducing a set of field windings into the saved space. In this paper, the steady-state characteristics, especially for...

The full operational capability of synthetic aperture radar (SAR) interferometry in deformation monitoring has not been achieved yet due to the negative influences of spatio-temporal decorrelation and atmospheric delay. With the use of time series of SAR images, deformation extraction can be however improved by only tracking some objects with steady radar reflectivity, generally referred to as ...