Introduction Dynamic Shimming (DS) is a technique for obtaining optimal B0 field homogeneity over a volume by updating the shim coil currents for every slice in a multislice acquisition in real time [1, 2]. While DS can theoretically produce better B0 homogeneity for each imaging subvolume than static, global volume shimming methods, its performance may be limited by eddy current fields produce...

Two robust techniques for quantification and compensation of eddy-current-induced magnetic-field gradients and static magnetic-field shifts (ΔB0) in MRI systems are described. Purpose-built 1-D or six-point phantoms are employed. Both procedures involve measuring the effects of a prior magnetic-field-gradient test pulse on the phantom's free induction decay (FID). Phantom-specific analysis of t...

In this paper, a novel hybrid excitation linear eddy current brake is presented as a braking system for high-speed road and rail vehicles. The presence of the permanent magnets (PMs), whose flux lines in the primary core are oppositely directed with respect to the flux lines by the excitation windings, has the effect of mitigating the saturation of the iron in the teeth of the primary core. Thi...

Detached-Eddy Simulation (DES) is a hybrid technique proposed in 1997 as a numerically feasible and plausibly accurate approach for predicting massively separated flows. Since its inception the method has been applied to a range of configurations including simple shapes such as cylinders, spheres and aircraft forebodies, in addition to complex geometries including fighter aircraft. The accuracy...

Abstract: A lot of progress is made in the last decade concerning the theoretical and practical aspects of eddy current testing. In addition to the defect characterization, actual studies deal with the metallurgical evaluation of materials. Surface examination allows the prediction of the material strength and consequently its life time. In order to obtain various microstructures and to modify ...

Two types of thin septum magnets, direct drive and eddy current, were c mainly in 2-D magnetic aspects. For the direct-drive type, the leakage field depend finite permeability of the magnet core and not on the thickness of the septum conduct suggested that the leakage field be controlled by reducing the current in the septum c or by using a correction coil. There were no significant differences...

Differential probes have existed for many years and have been produced in a variety of configurations. The common feature of these diverse probes is that they detect an ac magnetic field gradient, but it is the desired direction of gradient detection that results in the numerous design variations [1 ,2,3]. The probes commonly used in a production shop for nondestructive testing (NDT) are invari...

Calibration procedures for eddy current inspections often involve the use of artifact standards containing manufactured flaws. The manufactured flaw is assumed to be a good approximation of the type of flaw being sought during the inspection. These manufactured flaws are most often produced by electrical dis charge machining (EDM) , milling, or the controlled growth of fatigue cracks. With simp...