Abstract: Apparatus and methods for controlling an ultraviolet (UV) sterilization system that has one or more UV sources to achieve proper sterilization with minimal time and usage of power for the UV sterilization system. The UV sources are operated according to a set of control parameters including intensity of the UV light energy and an exposure time. The device may include: one or more sensors that are configured to measure UV light energy emitted by the UV sources and develop one or more signals; and a microcontroller that has an access to information of UV energy doses for various types of microorganisms. The microcontroller is configured to receive the signals from the sensors, determine a set of optimum values corresponding to the set of control parameters using the signals and the information, and send the set of optimum values to the UV sources to control the UV sources.

Abstract: Systems and methods for generating relatively cool microwave plasma. The present invention provides a microwave plasma nozzle that includes a gas flow tube through which a gas flows, and a rod-shaped conductor that is disposed in the gas flow tube and has a tapered tip near the outlet of the gas flow tube. A portion of the rod-shaped conductor extends into a microwave cavity to receive microwaves passing in the cavity. These received microwaves are focused at the tapered tip to heat the gas into plasma. The microwave plasma nozzle also includes a vortex guide between the rod-shaped conductor and the gas flow tube imparting a helical shaped flow direction around the rod-shaped conductor to the gas flowing through the tube. The microwave plasma nozzle further includes a mechanism for electronically exciting the gas and a shielding mechanism for reducing a microwave power loss through the gas flow tube.