Abstract: A cover structure for covering a portion of a surface of a body of water includes a first plate having a brim, a second plate having a brim, the second plate overlying and spaced apart from the first plate, a support structure coupling the first plate to the second plate, and the cover structure having a specific gravity for maintaining the first plate in a position covering a portion of the surface of a body of water, and maintaining the second plate below the portion of the surface of the body of water.

Abstract: A radio-based position location system for determining a relative position of a first object with respect to a second object may include a first radio operatively associated with the first object. A first directional antenna having at least a high gain region is mounted to the second object so that the high gain region is directed generally outwardly from the second object and defines a first detection zone. A second directional antenna having at least a high gain region is also mounted to the second object and is oriented so that the high gain region is also directed generally outwardly and defines a second detection zone. A second radio connected to the first and second directional antennas exchanges radio signals with at least the first radio to determine the relative position of the first object with respect to the second object at least in part by determining a time-of-flight of a radio signal.

Abstract: A method for retrofitting a piece of equipment having a flexible track assembly is disclosed and may include disassembling an existing idler shaft from an idler gear and from at least one bearing block attached to the piece of equipment. The method may also include attaching a sleeve within the opening of the idler gear. A new idler shaft may then be positioned within an opening of at least one of the bearing blocks and within an opening in the sleeve. The new idler shaft and idler gear being configured such that the new idler shaft, idler gear, and sleeve rotate together. The method may then include placing at least one bushing liner within the opening of at least one bearing block and attaching a retaining device to at least one end of the new idler shaft to retain the new idler shaft axially.

Abstract: Various embodiments provide new methods of rhenium recovery. The methods can include subjecting a metal-bearing solution to an activated carbon bed, and adsorbing rhenium onto the activated carbon. The methods can also include heating a basic aqueous elution solution and eluting the rhenium from the activated carbon with the heated elution solution.

Abstract: Apparatus for controlling a track on a tracked vehicle may comprise a drive system, a clutch, a brake, and a track control system to operate the clutch and the brake. A control signal generator operatively associated with the track control system produces control signals that vary at a first rate to cause the track control system to transition the clutch from an engaged state to a disengaged state and produces control signals that vary at a second rate to cause the track control system to transition the brake from an initial application state to a full application state, the second rate being less than the first rate.

Abstract: Methods and apparatus for locating and tracking objects in a mining environment are disclosed that include selecting an operational area within which the locations of a plurality of objects are to be determined and tracked over time. Radio transceiver systems and associated display systems provided to the plurality objects are operated to form an ad-hoc, peer-to-peer network. The relative positions of the various objects are determined by measuring the time-of-flight of radio signals exchanged between various ones of the radio transceiver systems and analyzing the time-of-flight of such exchanged radio signals. The relative positions of at least some of the objects within the operational area are then displayed on the display system.

Abstract: A radio-based position location system for determining a relative position of a first object with respect to a second object may include a first radio operatively associated with the first object. A first directional antenna having at least a high gain region is mounted to the second object so that the high gain region is directed generally outwardly from the second object and defines a first detection zone. A second directional antenna having at least a high gain region is also mounted to the second object and is oriented so that the high gain region is also directed generally outwardly and defines a second detection zone. A second radio connected to the first and second directional antennas exchanges radio signals with at least the first radio to determine the relative position of the first object with respect to the second object at least in part by determining a time-of-flight of a radio signal.

Abstract: A method for retrofitting a piece of equipment having a flexible track assembly is disclosed and may include disassembling an existing idler shaft from an idler gear and from at least one bearing block attached to the piece of equipment. The method may also include attaching a sleeve within the opening of the idler gear. A new idler shaft may then be positioned within an opening of at least one of the bearing blocks and within an opening in the sleeve. The new idler shaft and idler gear being configured such that the new idler shaft, idler gear, and sleeve rotate together. The method may then include placing at least one bushing liner within the opening of at least one bearing block and attaching a retaining device to at least one end of the new idler shaft to retain the new idler shaft axially.