A multiple padlock lock system for locking a first post to a second post has a common plate and connecting links. In some cases, amide compounds and amide polymers may include a core derived from an amide polyol and an organic polyacid or ester. The ceramic fibre layers undulate relative to one or more outer surfaces of the article. The method of forming the bipolar transistor includes forming an emitter stack on a substrate. Voxels that do not intersect any polygon in the polygonal surface may not be scan-converted. The powder material is comprised mainly of a compound containing at least an oxygen element, a sulfur element and at least one transition metal element.