The invention provides a paper roll, a bushing for a paper roll and a combination of a paper roll with a dispenser. In a subsequently-obtained computed tomography scan, the tube current is controlled using the orthogonal patient attenuation. The shaft and cover have a common axis of rotation. The outlets are oriented such that the plug latch recess is positioned on one side edge of the plug aperture. A plurality of AC power controllers control output AC power to overlap the power output from the DC supplies, respectively.