Abstract: Enhanced performance yarns (41, 81) which comprise, and are functional and economic alternatives to, 100% petroleum oil based virgin continuous filament yarns, and yarns of natural fibers and methods of making them. The yarns may comprise an inner portion of spun staple fibers of recycled plastic and an outer portion comprising a different material and incorporate highly significant amounts of recycled plastics, particularly post consumer recycled (PCR), thermoplastic material such as polyethylene terephthalate (PET) which contains medium to high levels of contamination. One embodiment of yarn comprises a core (17), an inner portion (5) of spun staple fibers surrounding the core, and an outer portion (41) comprising an inner helix (43) and an outer helix (45) formed of a material different from the inner helix.

Abstract: A magnetic thrust bearing (110) comprises a magnet (112) mounted on a shaft (114) and a plurality of equi-angularly spaced superconductors (116) mounted on a static structure (118). Each superconductor (116) is mounted onto the static structure (118) by a parallel hinge strip (120) which allows the superconductor (116) to move radially relative to the axis of rotation of the shaft (114). The radial movement of the superconductors (116) changes the cross-sectional area of the magnetic field between the magnet and the superconductors (116) and this changes the stiffness of the magnetic bearing (110). The superconductors (116) move radially due to the pivoting of the parallel hinge strips (120) due to changes in the loads acting on the magnetic bearing (110). It is possible to detect movement of the shaft and to actively move the superconductors to control the stiffness of the magnetic bearing and to control the clearance in the magnetic bearing as in FIG. 5.