Abstract: In an air sterilization system that includes a UV kill chamber for sterilizing air that is to be supplied to users, the effectiveness of killing or neutralizing pathogens is increased by including not only a UV light source of a certain intensity but also including a particle filter and providing short duration high intensity UV radiation. In the case of a user specific system that includes a face mask to supply air to a specific user, exhaled air from the face mask may be sterilized as well, either by using the same kill chamber or by using a separate kill chamber.

Abstract: Roadway and vehicular-mounted safety reflectors include a reflective field that incorporates a plurality of discrete crystals that internally reflect light and return the light in a desired directional pattern determined by the internal reflection characteristics and orientation of the crystals. The directional pattern is chosen to optimize the visibility and functionality of the reflector.

Abstract: Systems and methods for exposing fluids and other materials that may contain biohazards to ultraviolet radiation are provided. One system for exposing a fluid includes a baffled conduit for conveying the fluid so that the fluid flow and its exposure to ultraviolet radiation is rendered more uniform. Other systems include feedback for determining when to replace light sources and filters and to ensure proper biodosimetry. Additional methods and systems for exposing fluids and other materials that may contain biohazards are also provided.