Abstract:
An optical device assembly comprises a substrate with a component and fiber groove thereon. A segment of optical fiber is engaged with the fiber groove, which positions the fiber segment for optical coupling with a component on the substrate. A fiber retainer maintains the fiber segment in engagement with the groove. The fiber retainer may be secured to the substrate with adhesive means. Recessed regions formed on the substrate/retainer are filled with adhesive means, forming retaining members. Alternatively, the fiber retainer comprises a resilient member engaged with the device substrate and biased so as to urge the fiber segment into the groove. The resilient member may be variously configured and/or adapted for enhancing engagement of the fiber segment with the fiber groove. Either embodiment may include a housing, which may be variously configured and/or adapted for engaging a mating fiber-optic connector, providing fiber pigtail(s), mechanical splicing, and so forth.
Abstract:
Improved processes for producing substituted benzo(chalcogeno)[4,3,2-cd] indazoles. The processes produce compounds in higher yields and of greater purity by using a novel sequence of acylation chemistry and easily removed protecting groups. The compounds produced have antibacterial, antifungal, antileukemic, and antitumor activity.
Abstract:
A POSITION FINDING SYSTEM IS PROVIDED WHICH COMPRISES FOUR TRANSMITTING STATIONS, A FIRST PAIR OF WHICH PRODUCES A FIRST HYPERBOLIC POSITION LINE SYSTEM AND A SECOND PAIR OF WHICH PRODUCES A SECOND INTERSECTING HYPERBOLIC POSITION LINE SYSTEM. FIRST TRANSMITTERS OF EACH PAIR TRANSMIT UNMODULATED HIGH FREQUENCY WAVES IN FIRST AND SECOND CHANNELS RESPECTIVELY AND SECOND TRANSMITTERS OF EACH PAIR TRANSMIT HIGH FREQUENCY CARRIER WAVES IN THE FIRST AND SECOND CHANNELS RESPECTIVELY, EACH CARRIER WAVE BEING MODULATED WITH A DEGREE OF MODULATION LESS THAN 1 BY A DIFFERENT LOW FREQUENCY. THE MODULATION LESS THAN 1 BY TRANSMITTER OF THE FIRST PAIR IS EQUAL TO THE BEAT FREQUENCY OF THE HIGH FREQUENCY UNMODULATED AND CARRIER WAVES OF THE SECOND CHANNEL AND THE MODULATION OF THE SECOND TRANSMITTER OF THE SECOND PAIR IS EQUAL TO THE EAT FREQUENCY OF THE HIGH FREQUENCY UNMODULATED AND CARRIER WAVES OF THE FIRST CHANNEL.
Abstract:
The invention relates to a system (1) for recovering an ocean-bottom seismometer (2), intended to be provided on a ship. The system comprises a receiving device (11) having an at least partially rigid structure, a guide barrier (121) to define, with the hull of the ship (3), a zone for guiding the ocean-bottom seismometer (2) towards the receiving device (11). A movement system (13) makes it possible to move the receiving device (11) between a low position in which the receiving device (11) is at least partially submerged and a high position enabling an operator or an apparatus present on the ship (3) to recover the ocean-bottom seismometer (2) carried by the receiving device (11). The invention also relates to a ship provided with the system and to a corresponding recovery method.
Abstract:
In order to monitor the subsoil of the earth under a target zone, seismic waves coming from an identified mobile noise source are recorded by means of at least one pair of sensors disposed on either side of the target zone, time periods are selected corresponding to the alignments of the pairs of sensors with the noise source, a seismogram of the target zone is reconstructed by interferometry based on the recorded seismic waves and on the selected time periods and an image of the subsoil of the target zone is generated using the seismogram.
Abstract:
A method for seismic exploration of a subsurface formation with a seismic survey system includes directly receiving a message, at a first fleet of seismic sources, from a second fleet; storing the message at the first fleet; verifying one or more constraints related to the first and second fleets, at the first fleet; initiating a triggering sequence of the seismic sources of the first fleet, upon verification of the one or more constraints, with no input from a central unit of the seismic survey system; and performing a sweep based on the triggering sequence.
Abstract:
A seismic source using tuned pulse sources to form an ultra-low frequency (ULF) cluster intended for use in generating seismic energy impulses for marine seismic exploration and more specifically to improved performance by increasing low frequency output to within a range of 1 Hz to 3 Hz to provide greater penetration of the seismic signal through complex overburden such as salt or basalt.
Abstract:
A method for automatically propagating a voltage along a marine seismic streamer, the method including detecting, at an ith concentrator of the streamer, a first voltage applied at a first high-voltage rail HV1; detecting, at the ith concentrator of the streamer, a second voltage applied at a second high-voltage rail HV2, the first and second high-voltage rails extend over the entire streamer; checking a predetermined condition at a first local controller of the ith concentrator; and closing a first switch SW1, which propagates the first high-voltage rail HV1, when the predetermined condition is satisfied.
Abstract:
It is proposed a positioning assistance system for a vibrator truck, that is configured to determine a vibration point distance between the vibrator truck and the vibration point location; determine a stopping distance for stopping the vibrator truck at a vibration point location, according to a determined current speed of the vibrator truck and according to a speed profile; determine a time for stopping the vibrator truck at the vibration point location according to the current speed of the vibrator truck, when the stopping distance corresponds to said vibration point distance; and trigger the lifting down of the baseplate of the vibratory system, when at least the following condition is met: said stopping time is inferior or equal to a time for lifting down the vibratory system to the ground. Corresponding vibrator truck and method are also proposed.
Abstract:
A vibratory source for generating seismic signals includes a baseplate, and a lift and hydraulic actuator system configured to actuate the baseplate to impart seismic waves into the ground. The baseplate includes plural individual plates for contacting the ground.