Abstract: A vessel tracking system may be used to detect and report an alert condition of a vessel (e.g., an aircraft). A vessel tracking system may monitor one or more travel (e.g., flight) characteristics of a vessel. At least one of the travel characteristics may be compared to one or more normal flight characteristics to assess an alert condition of the vessel. In some embodiments, the alert condition of the vessel may be reported (e.g., visually reported on a display). The alert condition of the vessel may be changed if at least one of the travel characteristics deviates from at least one normal travel characteristic. In certain embodiments, a boundary condition of an alert for the vessel may be modified if at least one of the travel characteristics deviates from at least one normal travel characteristic.

Abstract: Apparatus and methods for improving the safety and efficiency and decreasing the cost of producing liquid oxygen with a small-scale use liquefaction device, according to various embodiments of the present invention. In one embodiment, a switch is electrically coupled to a storage dewar pressurizing means, the switch positioned to be activated by a portable dewar upon engagement of portable dewar with storage dewar. Cryocooler and/or cooling fan enter low power mode when dewar liquid level reaches a predetermined level, and to return to a fall power mode when dewar liquid level drops to another predetermined level. A cold finger of the cryocooler extends within the dewar and may prevent overfilling of the dewar. The cold finger has a temperature gradient. As the gas liquefies and fills the dewar, the liquid level rises only to a level on the cold finger at which the temperature exceeds the boiling point of oxygen.

Abstract: Apparatus and methods for improving the safety and efficiency and decreasing the cost of producing liquid gas, such as liquid oxygen, with a small-scale use liquefaction device, according to various embodiments of the present invention. In one embodiment, liquid oxygen barrier may be added to interface between a cryocooler and a dewar to control rate of liquid oxygen escape upon a tipping of the dewar. A boiloff vessel in fluid communication with the dewar allows expanding gas from a tipped dewar to escape while allowing the liquid to safely settle in the boiloff vessel. A temperature sensing circuit, in proximity with a heat dissipator or cold finger of the cryocooler, is operable to break an electrical power circuit of the cryocooler or cooling fan when a sensed temperature exceeds a predetermined temperature. Oxygen purity of a feed stream of gas may be sensed and/or displayed.

Abstract: The present invention provides a removably attachable compact desiccant cartridge that is useful in lowering the dew point of a medically useful gas, which is liquefied by a cryogenic device. The desiccant cartridge of the present invention comprises a gas feedstream inlet, a dehumidifying zone which comprises a desiccant material, and a dehumidified gas feedstream outlet. The present invention also provides a method for using the same.