Prototype development of a conduction-cooled LTS pulse coil for UPS-SMES

We are planning to develop a 1 MW, 1 sec UPS-SMES for a protection from a momentary voltage drop and an instant power failure. As the first step, we have been developing a 100 kJ class prototype UPS-SMES, using a low temperature superconducting coil because of its better cost and performance over the high temperature superconducting coil. However, the difficulty to utilize a pool-boiling LTS pulse coil is the reliability of operation. To solve this problem, a conduction-cooled LTS pulse coil has been designed and fabricated as a key component of the UPS-SMES. The reduction of AC loss and high stability are required for the SC conductor for the conduction-cooled coil because of a limited cooling capacity. The SC conductor of a NbTi/Cu compacted strand cable extruded with an aluminum is designed to have the anisotropic AC loss properties to minimize the coupling loss under the specified orientation of the time varying magnetic field. The coil was wound with a new twist-winding method in which the variation of twist angle of the conductor was controlled with the winding machine designed specifically for this purpose. The fabrication technique and performance of a conduction-cooled prototype LTS pulse coil are described

3D static and time-dependent modelling of a dc transferred arc twin torch system

International audienceThe transferred arc plasma torch device consists of two electrodes generating a plasma arc sustained by means of an electric current flowing through the body of the discharge. Modeling works investigating of transferred electric arc discharges generated between two suspended metallic electrodes, in the so called twin torch configuration, are scarce. The discharge generated by this particular plasma source configuration is characterized by a complex shape and fluid dynamics and needs a 3D description in order to be realistically predicted. The extended discharge length that goes from the tungsten pencil cathode to the flat copper anode without any particular confinement wall and the fluid dynamics and magnetic forces acting on the arc may induce an unsteady behavior. In order to capture the dynamic behavior of a twin torch discharge, a 3D time dependent plasma arc model has been developed using a customized commercial code FLUENT form in both Local Thermodynamic Equilibrium (LTE) and non-LTE. A two temperature (2T) model has been developed taking into account only the thermal non-equilibrium effects in argon plasma. The main differences between LTE and 2T models results concern the increased extension of the horizontal section of the discharge and the predicted reduced (of about 60-80V) voltage drop between the electrodes when using a 2T model

Clinical, serologic and magnetic resonance imaging of 3 cases of inflammatory myopathy with abundant macrophages in the Japanese population

We report the first 3 cases of inflammatory myopathy with abundant macrophages (IMAM) to be found in an Asian country. Diagnosis of IMAM was based on the infiltration of CD68+ macrophages into biopsied specimens, particularly the fascia. Proximal skeletal muscle symptoms and signs, elevation of creatine kinase, and myogenic changes in electromyography were found in all of the cases, and magnetic resonance imaging clearly revealed thickening of the fascia. Since dermatomyositis (DM)-specific skin alterations were not found, none of the patients in this study fulfilled Bohan and Peter\u27s criteria for DM; however, anti-PL-7 antibody was detected in case number 1. In addition, CD20+ B-cell infiltration into the fascia was also detected in all of the cases, indicating further transition to DM. Severe illness, namely macrophage activation syndrome and acute respiratory distress syndrome, occurred in case 1 but was resolved with intensive combination therapy. The other 2 cases also required glucocorticoids to achieve remission