Abstract: A method of fracturing a subsurface formation includes super-cooling liquid carbon dioxide to a temperature between ?60° F. to ?70° F. using liquid nitrogen having a temperature in a range of ?100° F. to ?200° F., pumping the lipid carbon dioxide down a wellbore to create fractures in the subsurface formation, and pumping fracturing fluid containing a proppant down the wellbore after pumping the liquid carbon dioxide down the wellbore.

Abstract: A method and system for controlling the operation of a vehicle is disclosed that includes a radio frequency transponder and a vehicle configured to respond to data stored in the transponder by preventing or disabling operation of the vehicle under certain conditions indicated by data stored in the transponder. A communications controller receives the data from the transponder, then monitors the operation of the vehicle to make sure it is operated within the limits that are stored in the transponder. By communicating with other controllers on the vehicle that are in charge of other subsystems, it receives information relating to whether the operational limits of the vehicle have been approached or exceeded, and takes appropriate action in that event, the action may include not enabling the vehicle initially, or disabling the vehicle, or causing an operator display to indicate which limit has been exceeded or approached.

Abstract: A system and method for permitting different authorized degrees of access to two or more users of a vehicle in a fleet of vehicles. Each user has a radio (RF) transponder coupled to an ignition key that operates the ignition switch of the vehicle. The transponder stores data indicating the degree of operating access authorized to each user for the vehicle.

Abstract: A hydraulic actuator is disclosed having a cylinder with a piston that is moved by hydraulic fluid. A light guide in one end of the cylinder directs a laser beam into the cylinder, and off the piston where the beam is reflected. The beam then exits the cylinder through a second light guide. A control unit measures the time of flight of the laser beam and calculates the piston position.

Abstract: A hydraulic actuator is disclosed having a cylinder with a piston that is moved by hydraulic fluid. A light guide in one end of the cylinder directs a laser beam into the cylinder, and off the piston where the beam is reflected. The beam then exits the cylinder through a second light guide. A control unit measures the time of flight of the laser beam and calculates the piston position.

Abstract: A method and system for controlling the operation of a vehicle is disclosed that includes a radio frequency transponder and a vehicle configured to respond to data stored in the transponder by preventing or disabling operation of the vehicle under certain conditions indicated by data stored in the transponder. A communications controller receives the data from the transponder, then monitors the operation of the vehicle to make sure it is operated within the limits that are stored in the transponder. By communicating with other controllers on the vehicle that are in charge of other subsystems, it receives information relating to whether the operational limits of the vehicle have been approached or exceeded, and takes appropriate action in that event. the action may include not enabling the vehicle initially, or disabling the vehicle, or causing an operator display to indicate which limit has been exceeded or approached.