Abstract: Methods and apparatus for analyzing a hydrocarbon mixture are disclosed, comprising at least one light-emitting diode (LED) and at least one photodetector positioned to detect energy transmitted by the LED through a sample of the hydrocarbon mixture. In at least one embodiment an optical filter is coupled to the output of the LED to mitigate the adverse effects of the LED's sensitivity to temperature.

Abstract: A method and apparatus for electrically interfacing between two or more distinct environments. The method and apparatus are directed to an electrical feedthru with one or more electrical transmission lines coated with one or more thin dielectric layers of material to insulate the transmission lines from a feedthru body. The dielectric layers may include a diamond-like carbon coating, which electrically insulates, but also thermally conducts. The use of thin dielectric layers facilitates smaller, more efficient electrical feedthrus. Therefore, the electrical feedthru may be used, for example, with MEMS devices. The electrical feedthru is not limited to any particular geometry, it may be adapted to fit between any two environments.

Abstract: Apparatus and methods are utilized for controlling downhole equipment attached to a drill string by the transmission of commands from the surface of the earth. The drill string is rotated at the surface of the earth sequentially through one or more discrete angles of rotation to generate a command code. The sequence of discrete angular rotations is sensed downhole by a gyroscope and decoded as a command in a microprocessor. Alternately, a command code is transmitted by sequentially rotating the drill string at different angular rates which are likewise sensed by the gyroscope and decoded in the microprocessor. The microprocessor then transmits the decoded command to the controlled equipment.