Abstract: The present disclosure relates generally to a process for producing polymer fibers, typically polyacrylonitrile-based fibers, the properties of which are controlled by certain parameters of the process, such as the amount of jet stretch, the amount of wet stretch, and the amount of hot stretch employed. The present disclosure also relates to a process for producing carbon fiber from such polymer fibers.

Abstract: Example embodiments relate to tiltable luminaire joints. One example tiltable joint for a luminaire includes a first joint portion that includes a joint member provided with an outer cylindrical surface section having an axis and opposing bearings aligned with said axis. The outer cylindrical surface section being provided with a first plurality of interengaging surfaces. The tiltable joint also includes a second joint portion that includes a joint housing provided with a pair of axially-aligned receiving surfaces, and an inner cylindrical surface provided with a second plurality of interengaging surfaces configured to interengage the first plurality of interengaging surface. The joint member of the first joint portion is configured for being housed within the joint housing of the second joint portion. Further, the tiltable joint includes first and second shaft portions that extend in alignment with the pair of axially-aligned bearings. Additionally, the tiltable joint includes a fixation means.