Abstract: A downhole compressor system is disclosed for assisting in extracting gas from the well. The system comprises a compressor 14, an electric motor 10 for driving the compressor 14 which motor has a stator winding and a rotor 12 and, in use, is lowered into the well together with the compressor. A control system 18, which when in use is disposed outside the well, is connected to the stator winding for controlling the current supply to the motor 10. The control system 18 receiving a signal indicative of the speed and phase of the rotor from a feedback sensor 16 mounted for rotation with the rotor 12. In the invention, the feedback sensor is a current generator having a permanent magnet 16a mounted for rotation with the rotor 12 and a second stator winding 16b connected to the control system 18.

Abstract: A magnetic head slider having an air bearing surface is used for reading and writing data from a magnetic medium. The magnetic head includes a substrate having a disc opposing face bounded by a leading face, a trailing face, and first and second sided edges. The slider includes an end layer positioned upon the trailing face of the substrate wherein the basecoat has a disc opposing face and is comprised of a material having a coefficient of thermal expansion greater than a coefficient of thermal expansion of the substrate. An air bearing pad is formed solely on the disc opposing face of the end layer. A transducing head is formed in the air bearing pad and exposed at an air bearing surface.

Abstract: A flow allocation system includes a set of collection agents, a set of restriction agents, a processing agent and at least one usage limit selected from a volume limit set and a rate limit set. The flow allocation system is implemented between a set of usage devices and a service network. The collection agents monitor flows between the usage devices and the service network. The processing agent sums the flows for each of the usage devices, determines whether any of the summed flows reach the usage limit, and selects at least one flow restriction rule for the subset of usage devices reaching the usage limit. The set of restriction agents implement the flow restriction control rule for the subset of usage devices reaching the usage limit. The processing agent also uses exception handling techniques to shift usage quotas for the usage devices.