Abstract: A light pipe for use in aqueous environments comprising an optical rod capable of total internal reflection, and disposed in the optical path of a light source such as a light emitting diode or other source. The optical rod has frosted and unfrosted portions, such that the light is propagated distally along the rod at the unfrosted portions, but a portion of the light is coupled out of the rod into the aqueous environment at each of the frosted portions. The relative sizes of the frosted portions are arranged so that substantially the same light power is coupled out of the rod at each frosted section, thus facilitating rapid and uniform growth of algae in the aqueous environment.

Abstract: A light pipe for use in aqueous environments comprising an optical rod capable of total internal reflection, and disposed in the optical path of a light source such as a light emitting diode or other source. The optical rod has frosted and unfrosted portions, such that the light is propagated distally along the rod at the unfrosted portions, but a portion of the light is coupled out of the rod into the aqueous environment at each of the frosted portions. The relative sizes of the frosted portions are arranged so that substantially the same light power is coupled out of the rod at each frosted section, thus facilitating rapid and uniform growth of algae in the aqueous environment.

Abstract: A light pipe for use in aqueous environments comprising an optical rod capable of total internal reflection, and disposed in the optical path of a light source such as a light emitting diode or other source. The optical rod has frosted and unfrosted portions, such that the light is propagated distally along the rod at the unfrosted portions, but a portion of the light is coupled out of the rod into the aqueous environment at each of the frosted portions. The relative sizes of the frosted portions are arranged so that substantially the same light power is coupled out of the rod at each frosted section, thus facilitating rapid and uniform growth of algae in the aqueous environment.

Abstract: A light pipe for use in aqueous environments comprising an optical rod capable of total internal reflection, and disposed in the optical path of a light source such as a light emitting diode or other source. The optical rod has frosted and unfrosted portions, such that the light is propagated distally along the rod at the unfrosted portions, but a portion of the light is coupled out of the rod into the aqueous environment at each of the frosted portions. The relative sizes of the frosted portions are arranged so that substantially the same light power is coupled out of the rod at each frosted section, thus facilitating rapid and uniform growth of algae in the aqueous environment.

Abstract: A bubble column for facilitating algae growth comprised a tank adapted to contain a volume of growth medium with algae growing therein, with a light pipe disposed centrally therein and extending from near the top surface of the growth medium in the tank to near the bottom of the tank. The light pipe illuminates substantially the entire volume of the growth medium. A diffuser is positioned at or near the bottom of the tank and receives a gas stream, and converts the gas stream to a stream of bubbles that agitate the algae without creating a fluid flow within the tank.

Abstract: A sterilizer for sterilizing objects with biocidal gas which is designed to resist the deleterious effects of the biocidal gas. The invention provides a sterilizer having a sterilizing chamber for holding the objects to be sterilized, and a gas control system for manipulating the gaseous environment within the sterilizing chamber. The sterilizer has a vacuum control system, a vacuum line in fluid communication with the sterilizing chamber, a humidity sensor connected to that vacuum line at a point removed from or outside of the sterilizing chamber, and an isolation valve connected to the vacuum line at a point between the sterilizing chamber and the humidity sensor for temporarily isolating the humidity sensor from the sterilizing chamber. This arrangement assures that the humidity sensor received a sufficient sample for reading the adequacy of the humidification of the objects to be sterilized, while at the same time protecting it from the biocidal gas.