摘要:
The present invention relates to an apparatus for use in geophysical surveying. Geophysical surveying typically involves stimulating an area of interest with a seismic source (204) and detecting the response in a sensor array. The application describes a fiber optic distributed sensing apparatus having a source (112) of electromagnetic radiation for repeatedly launching interrogating electromagnetic radiation into an optic fiber (104) deployed in said of area interest, a sampling detector (116) for sampling radiation back-scattered from the fiber; and a processor (108) arranged to process the back-scattered radiation to provide, for each of a plurality of longitudinal sensing portions of optic fiber, an indication of any incident acoustic signals affecting that sensing portion. The sampling detector is arranged to acquire a plurality of diversity samples for each said longitudinal sensing portion. The processor is configured process the diversity samples in diversity channels to determine a measurement signal indicative of any acoustic disturbance; correlate the measurement signal from each channel with a signal indicative of the seismic stimulus applied; and combine the correlated measurement signals to provide an overall measurement signal for the longitudinal sensing portion. The processor may apply a quality metric to the correlated data before performing the combination based on the quality metric. By correlating the individual diversity channels with the stimulus signal prior to performing the analysis of the measurement signal for a particular longitudinal section of optic fiber, the signal to noise ratio can be improved.
摘要:
A telecommunications system including, a plurality of repeater nodes, each repeater node having a transceiver unit operable to transmit and receive data to or from one or more other of the repeater nodes or a control node or a mobile device within a predetermined range. The control node operable to transmit data to and receive data from the mobile device via the repeater nodes using a time frame divided into a plurality of time slots. The time slots of the time frame are allocated to the repeater nodes to the effect that each repeater node transmits to another repeater node in one of the upstream or the downstream directions in a time slot which is a minimal time from the time slot in which the other repeater node transmits in the upstream or downstream direction.
摘要:
A method for filling needleless injector capsules with liquid drug, whereby dissolved gas within the drug is replaced by a less soluble gas in order to reduce the inclusion of gas bubbles, or to prevent the growth of bubbles during storage and thereby prevent breakage of the capsules.
摘要:
There is provided a distributed sensor, comprising a length of optic fibre; an interrogator unit having a detector arranged to detect light from the optic fibre, wherein the interrogator is arranged to provide distributed sensing on the optic fibre and wherein an optical path is defined between the optic fibre and the interrogator detector; a sampler coupled to the optic fibre and arranged to obtain a sample of light from the optical path of the optic fibre; a threshold detector arranged to detect the intensity of the sampled light and determine whether the intensity of the sampled light is above a threshold value; and an optical attenuator provided in the optical path and arranged to attenuate light propagating along the optical path when the intensity of the sampled light is above the threshold value. By attenuating light in the optical path if it is above a threshold value, the sensitive detector in the interrogator unit can be protected.
摘要:
The present invention relates to an apparatus for use in geophysical surveying. Geophysical surveying typically involves stimulating an area of interest with a seismic source and detecting the response in a sensor array. The application describes a fibre optic distributed sensing apparatus having a source (112) of electromagnetic radiation for repeatedly launching interrogating electromagnetic radiation into an optic fibre (104) deployed in said of area interest, a sampling detector (116) for sampling radiation back-scattered from the fibre; and a processor (108) arranged to process the back-scattered radiation to provide, for each of a plurality of longitudinal sensing portions of optic fibre, an indication of any incident acoustic signals affecting that sensing portion. The sampling detector is arranged to acquire a plurality of diversity samples for each said longitudinal sensing portion. The processor is configured process the diversity samples in diversity channels to determine a measurement signal indicative of any acoustic disturbance; correlate the measurement signal from each channel with a signal indicative of the seismic stimulus applied; and combine the correlated measurement signals to provide an overall measurement signal for the longitudinal sensing portion. The processor may apply a quality metric to the correlated data before performing the combination based on the quality metric. By correlating the individual diversity channels with the stimulus signal prior to performing the analysis of the measurement signal for a particular longitudinal section of optic fibre, the signal to noise ratio can be improved.
摘要:
A telecommunications system for communicating data to and from a mobile device. The system comprises a plurality of repeater nodes disposed to form a network. Each repeater, node has a transceiver unit operable to transmit the data with a first transmission power to one or more other of the repeater nodes within one of a plurality of slots of a time frame. Each repeater node is allocated a time slot, and the mobile device is arranged to transmit and receive data to and from the repeater nodes in the network. Each of the repeater nodes is operable to transmit a pilot signal during the same one of the time slots of the time frame with a second transmission power, the second power being less than the first transmission power. The pilot signal includes an identifier of the repeater node which is transmitted with the pilot signal and the mobile device is operable to receive one of the pilot signals.
摘要:
A distributed file system is disclosed. A plurality of disk servers, operating as a single distributed disk server layer, are connected to the one or more physical disks. Each disk server stores meta-data for each of the files. A plurality of lock servers, having one or more locks for each file operates as a single distributed lock server to coordinate access to the files stored by the disk server layer. A plurality of asynchronous file servers, operating as a single distributed file server layer in response to a request for a file from a user program: (i) retrieves the requested file from the disk server layer and at least one lock, associated with the retrieved file, from the lock server, and (ii) retrieves meta-data for at least one file that is related to the requested files, and at least one lock, for each file that has had its meta-data retrieved.
摘要:
A pharmaceutical composition for embolisation of blood vessels, especially for benign tumours, comprises a polymeric embolic agent and, associated with the polymer in a releasable form, a local anaesthetic agent. The polymer is preferably in particulate form, such as in the form of microspheres. A suitable polymer is a crosslinked polyvinyl alcohol polymer formed by the copolymerisation of PVA macromer with other ethylenically unsaturated monomers. The composition provides a synergistic treatment for the symptoms of tumours such as uterine fibroids, leading to size regression as well as pain relief.