Abstract As an important part in the active magnetic bearing, its performance has great impact on bearing system. Most of systems use current-mode switching power amplifiers. The full-bridge converter is main topological structure amplifier for bearings. It mainly supplies current to coil so it can offer enough fore rotor. abundant nonlinear phenomena as conversion device lies region. This pape...

OBJECTIVES Hips with metal-on-metal total hip arthroplasty (MoM THA) have a high rate of adverse local tissue reactions (ALTR), often associated with hypersensitivity reactions. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measures tissue perfusion with the parameter Ktrans (volume transfer constant of contrast agent). Our purpose was 1) to evaluate the feasibility of DCE-MRI ...

background: according to recent studies comparing magnetic resonance enterography (mre) with ileocolonoscopy for assessing inflammation of small bowel and colonic segments in adults with active crohn’s disease (cd), we aimed to compare the accuracy of these two diagnostic methods in iranian population. method: during 2013-2014 a follow-up study was done on 30 patients with active cd ina gastroe...

Modern small diameter metal-on-metal (MoM) bearings for total hip arthroplasty (THA) have been developed in the nineteen-eighties to address the problem of polyethylene wear related osteolysis. Subsequently large diameter MoM hip resurfacings (HRA) were designed for young and active patients to preserve bone and avoid dislocation. Large diameter MoM THA were originally meant as an easy femoral ...

Abstract: In order to overcome the shortcoming of magnetic bearings whereby general mathematical models of the radial suspension forces cannot be accurately established, a mathematical model considering the edge effect is set up. The configuration, operation principle and flux distribution features of a three-pole radial hybrid magnetic bearing (HMB) are analyzed in this paper. The magnetic fie...

In the rotating electrical machines, active magnetic bearing are basically performing the same role like mechanical bearings to support rotor. The function is based on the principle of magnetic levitation. The idea behind this involves creation of a magnetic field by supplying controlled currents in the bearing coil through amplifiers and complex power electronics. The accurate design of a magn...

The paper considers three issues in flexible rotor and magnetic bearing systems, namely control of rotor vibration, control of transmitted forces, and prevention of rotor contact with auxiliary bearings. An adaptive multi-objective optimization method is developed to tackle these issues simultaneously using a modified recursive open loop adaptive controller. The proposed method involves automat...