摘要:
A transducer is described especially for use in providing acoustic transmission in a borehole. The transducer includes a multiple number of magnetic circuit gaps and electrical windings that have been found to provide the power necessary for acoustic operation in borehole while still meeting the stringent dimensional criteria necessitated by boreholes. Various embodiments conforming to the design are described. Moreover, the invention includes transition and reflector sections, as well as a directional coupler and resonator arrangement particularly adapted for borehole acoustic communication.
摘要:
A transducer is described especially for use in providing acoustic transmission in a borehole. The transducer includes a multiple number of magnetic circuit gaps and electrical windings that have been found to provide the power necessary for acoustic operation in a borehole while still meeting the stringent dimensional criteria necessitated by boreholes. Various embodiments conforming to the design are described. Moreover, the invention includes transition and reflector sections, as well as a directional coupler and resonator arrangement particularly adapted for borehole acoustic communication. An acoustic communication system is described especially designed for use in providing acoustic transmission of information in a borehole. The communication system comprises a surface transceiver and at least one downhole transceiver. The surface transceiver operates in conjunction with a host computer that sends commands to the downhole transceiver. Subsequently, the downhole transceiver transmits encoded data from subsurface, borehole sensors to the surface transceiver. The preferred embodiment uses Minimum Shift Keying (MSK) modulation for both transmitting commands to the downhole unit and for transmitting data to the surface transceiver. To facilitate operation of a coherent communication system in the inhospitable environment of a borehole, the acoustic channel is characterized to enable the system to choose the best possible frequency and bandwidth for communication transmission. Additionally, the system achieves synchronous operation by transmitting synchronization signals between the downhole transceiver and the surface transceiver prior to the units exchanging commands and data.
摘要:
A transducer is described especially for use in providing acoustic transmission in a borehole. The transducer includes a multiple number of magnetic circuit gaps and electrical windings that have been found to provide the power necessary for acoustic operation in a borehole while still meeting the stringent dimensional criteria necessitated by boreholes. Various embodiments conforming to the design are described. Moreover, the invention includes transition and reflector sections, as well as a directional coupler and resonator arrangement particularly adapted for borehole acoustic communication.An acoustic communication system is described especially designed for use in providing acoustic transmission of information in a borehole. The communication system comprises a surface transceiver and at least one downhole transceiver. The surface transceiver operates in conjunction with a host computer that sends commands to the downhole transceiver. Subsequently, the downhole transceiver transmits encoded data from subsurface, borehole sensors to the surface transceiver. The preferred embodiment uses Minimum Shift Keying (MSK) modulation for both transmitting commands to the downhole unit and for transmitting data to the surface transceiver. To facilitate operation of a coherent communication system in the inhospitable environment of a borehole, the acoustic channel is characterized to enable the system to choose the best possible frequency and bandwidth for communication transmission. Additionally, the system achieves synchronous operation by transmitting synchronization signals between the downhole transceiver and the surface transceiver prior to the units exchanging commands and data.
摘要:
Apparatus (48), and an associated method, for facilitating operation of a mobile node (12) operable in a communication system (10) to request allocation of communication capacity upon which to communicate data pursuant to a communication service. A channel allocation request generator (52) is selectably operable to generate requests for allocation of channel capacity upon which to communicate the data. A selector (54) selects when to cause the generator (52) to communicate the additional data packets. Selection is made to delay, or otherwise prevent, retransmission of requests, when a determination is made that the retransmission is unlikely to be successful.
摘要:
Apparatus (48), and an associated method, for facilitating operation of a mobile node (12) operable in a communication system (10) to request allocation of communication capacity upon which to communicate data pursuant to a communication service. A channel allocation request generator (52) is selectably operable to generate requests for allocation of channel capacity upon which to communicate the data. A selector (54) selects when to cause the generator (52) to communicate the additional data packets. Selection is made to delay, or otherwise prevent, retransmission of requests, when a determination is made that the retransmission is unlikely to be successful.
摘要:
A method and system of matching a bit rate to a transmit bit rate used to transmit data on a data link are disclosed. A bit pattern in data received on the data link is detected using a bit rate. Where the detected bit pattern comprises one of a plurality of expected bit patterns, the bit rate is adjusted to an adjusted bit rate based on the detected bit pattern. In one embodiment, the adjusted bit rate is used for communications on the data link when a confirmation bit pattern is received within a predetermined time after the data is received.
摘要:
A method and system of matching a bit rate to a transmit bit rate used to transmit data on a data link are disclosed. A bit pattern in data received on the data link is detected using a bit rate. Where the detected bit pattern comprises one of a plurality of expected bit patterns, the bit rate is adjusted to an adjusted bit rate based on the detected bit pattern. In one embodiment, the adjusted bit rate is used for communications on the data link when a confirmation bit pattern is received within a predetermined time after the data is received.
摘要:
Apparatus (48), and an associated method, for facilitating operation of a mobile node (12) operable in a communication system (10) to request allocation of communication capacity upon which to communicate data pursuant to a communication service. A channel allocation request generator (52) is selectably operable to generate requests for allocation of channel capacity upon which to communicate the data. A selector (54) selects when to cause the generator (52) to communicate the additional data packets. Selection is made to delay, or otherwise prevent, retransmission of requests, when a determination is made that the retransmission is unlikely to be successful.
摘要:
A heat sink for electronic components having a heat dissipator connected to at least one electronic component and a ventilator designed to supply the heat dissipator with air. The heat dissipator includes at least one thermally conductive plate connected to the electronic component and having a plurality of openings.
摘要:
A system for delivering measured amounts of liquid, such as reagents used in chromatography. Liquid is first moved under gas pressure from a reservoir, such as a reagent bottle, through a valve into a narrow pipe. It reaches a detector which, detecting its presence, closes the valve thus trapping an amount of liquid between the valve and the detector, this amount of liquid then constituting a `unit` or `pulse` of liquid. The movement of the valve is used to connect a gas supply which drives the `unit` or `pulse` out of the pipe to an ultimate destination, such as a chromatographic column. A further `unit` or `pulse` can then be moved into the pipe and this repeated so that delivery to the destination is made in a series of such `units` or `pulse`. By timing the delivery of one `unit` or `pulse`, an amount less than one `unit` or `pulse` can be delivered by passing liquid into the pipe for less than the time taken to deliver one `unit`. This can be used to make up a delivery which is not a unitary multiple of one `unit` or to deliver a small amount of less than one `unit`. No moving parts are involved and delivery of accurately measured amounts is achieved.