Abstract: An embodiment of a device for generating an acoustic signal in a fluid includes an engine operable to repeat a thermodynamic process to vibrate a membrane of the engine to generate an acoustic signal having more than one period. The thermodynamic process includes heating mass inside a chamber of an engine to generate pressure inside the chamber; in response to generating the pressure, moving in a first direction a portion of a membrane of the engine; removing mass from inside the chamber to decrease the pressure inside the chamber; and in response to decreasing the pressure inside the chamber, moving the membrane portion in a second direction. In an embodiment, because the engine repeats the thermodynamic process, the engine can generate and sustain an acoustic signal for a significant amount of time.

Abstract: A substance is added to cold ocean water in a cold water pipe of an Ocean Thermal Energy Conversion (OTEC) system. The substance raises the freezing point of the ocean water in a cold water heat exchanger of the OTEC system, thereby forming an ice slurry. The substance is added at the depth of the apparatus. The ice slurry is transported from the point of addition in the cold water pipe to the cold water heat exchanger at the surface.

Abstract: An unguided projectile-accelerator system includes an enclosure, first and second charges, first and second projectiles, and a recoil-absorbing mechanism. The enclosure has an open first end and a closed second end, and the first and second charges are disposed within the enclosure. The first projectile is disposed within the enclosure between the first charge and the first end and is operable to exit the enclosure via the first end and to generate a first recoil in response to detonation of the first charge. The second projectile is disposed within the enclosure between the first charge and the second charge and is operable to exit the enclosure via the first end and to generate a second recoil in response to detonation of the second charge. The recoil-absorbing mechanism is disposed adjacent to the enclosure and is operable to absorb at least a respective portion of each of the first and second recoil.

Abstract: A projectile system includes an enclosure, first and second propellants, and first and second projectiles. The first and second propellants are disposed within the enclosure. The first projectile is disposed within the enclosure between the first propellant and a first end of the enclosure, and is operable to exit the enclosure via the first end in response to detonation of the first charge. The second projectile is disposed within the enclosure between the second propellant and a second end of the enclosure, and is operable to exit the enclosure via the second end in response to the detonation of the second propellant.

Abstract: A ballistic-acoustic transducer system includes a processor and one or more acoustic sensors. The sensors are positioned in a body of water and are in communication with the processor. The system is configured such that acoustic energy generated by a non-explosive projectile as it impacts the water, enters the water, and sinks through the water, is sensed by the one or more acoustic sensors, and the processor is configured to process the acoustic energy sensed by the one or more acoustic sensors.

Abstract: A system for relieving the stress on an Ocean Thermal Energy Conversion (OTEC) cold water pipe includes a slidable joint that couples the OTEC cold water pipe to a surge tank at an opening in the surge tank. The system can further include a first flotation device that is coupled to the OTEC cold water pipe below the surge tank, and a second flotation device that is coupled to the OTEC cold water pipe within the surge tank.

Abstract: Sampling of a captured signal is synchronized to a tonal which may be unstable in frequency detected in the signal to cause it and all of its harmonics, sub-harmonics and fundamental to appear to have a substantially constant frequency relative to the sampling rate even if some related signals are otherwise undetectable amid noise. By adjusting an integration period of a fast Fourier transform to extract an intrinsic bandwidth, substantial signal processing gain can be obtained for the tonal and harmonically related signals, even if otherwise undetectable. Signal processing may be performed in either the time domain or the frequency domain. Recursive processing is performed to observe unrelated tones by grouping of tones which are harmonically related and supports detection of relationships between acoustic signal sources.

Abstract: A microfluidic pump has an outer housing such as a capillary tube, a nanotube, and an ionic fluid or alcohol. The nanotube is placed inside the capillary tube, and the capillary tube is filled with the ionic fluid or alcohol. A voltage source is connected to the nanotube, and upon application of a voltage to the nanotube, the ionic fluid or alcohol is pumped through the capillary tube.

Abstract: A system for relieving the stress on an Ocean Thermal Energy Conversion (OTEC) cold water pipe includes a slidable joint that couples the OTEC cold water pipe to a surge tank at an opening in the surge tank. The system can further include a first flotation device that is coupled to the OTEC cold water pipe below the surge tank, and a second flotation device that is coupled to the OTEC cold water pipe within the surge tank.

Abstract: A system of cluster depth charges increases the probability of inflicting damage on an underwater target. In an embodiment, the cluster depth charges are within a housing, and have intelligent sensor, buoyancy, and tracking and homing systems. In another embodiment, the cluster depth charges have a gun attached to a buoyancy section. In another embodiment, the cluster depth charges have magnets so that the cluster depth charges can attach to the target.

Abstract: Sampling of a captured signal is synchronized to a tonal which may be unstable in frequency detected in the signal to cause the detected tonal and all of its harmonics, sub-harmonics and fundamental to appear to have a substantially constant frequency relative to the sampling rate to facilitate observation and other signal processing even if some related signals are otherwise undetectable amid noise. By adjusting an integration period of a corresponding output of a fast Fourier transform to extract an intrinsic bandwidth, substantial signal processing gain can be obtained for the tonal and harmonically related components of the signal, even if some harmonically related signals are otherwise undetectable. Signal processing may be performed in either the time domain or the frequency domain. Recursive processing to observe as many unrelated tones as possible by grouping of tones which are harmonically related.

Abstract: A substance is added to cold ocean water in a cold water pipe of an Ocean Thermal Energy Conversion (OTEC) system. The substance raises the freezing point of the ocean water in a cold water heat exchanger of the OTEC system, thereby forming an ice slurry. The substance is added at the depth of the apparatus. The ice slurry is transported from the point of addition in the cold water pipe to the cold water heat exchanger at the surface.

Abstract: A system and process to extract one or more rare gases from a feed gas using a centrifuge.

Abstract: A process includes degassing ocean or sea water in an ocean thermal energy conversion (OTEC) system, and then extracting one or more noble gases from the out-gas of the ocean or sea water. An OTEC system capable of degassing ocean or sea water and extracting noble gases therefrom is also described.

Abstract: A device for generating an acoustic signal in a fluid includes an engine operable to repeat a thermodynamic process to vibrate a membrane of the engine to generate an acoustic signal having more than one period. The thermodynamic process includes heating mass inside a chamber of an engine to generate pressure inside the chamber; in response to generating the pressure, moving in a first direction a portion of a membrane of the engine; removing mass from inside the chamber to decrease the pressure inside the chamber; and in response to decreasing the pressure inside the chamber, moving the membrane portion in a second direction. Because the engine repeats the thermodynamic process, the engine can generate and sustain an acoustic signal for a significant amount of time.

Abstract: A device for generating an acoustic signal in a fluid includes an engine operable to repeat a thermodynamic process to vibrate a membrane of the engine to generate an acoustic signal having more than one period. The thermodynamic process includes heating mass inside a chamber of an engine to generate pressure inside the chamber; in response to generating the pressure, moving in a first direction a portion of a membrane of the engine; removing mass from inside the chamber to decrease the pressure inside the chamber; and in response to decreasing the pressure inside the chamber, moving the membrane portion in a second direction. Because the engine repeats the thermodynamic process, the engine can generate and sustain an acoustic signal for a significant amount of time.

Abstract: A device for generating an acoustic signal in a fluid includes an engine operable to repeat a thermodynamic process to vibrate a membrane of the engine to generate an acoustic signal having more than one period. The thermodynamic process includes heating mass inside a chamber of an engine to generate pressure inside the chamber; in response to generating the pressure, moving in a first direction a portion of a membrane of the engine; removing mass from inside the chamber to decrease the pressure inside the chamber; and in response to decreasing the pressure inside the chamber, moving the membrane portion in a second direction. Because the engine repeats the thermodynamic process, the engine can generate and sustain an acoustic signal for a significant amount of time.

Abstract: A signal analyzer system comprises a differential operator configured to receive at least one input signal, and to determine at least one locus based on instantaneous differences in a relative rate of change between the at least one input signal and the at least one input signal's at least one nth-order derivative, wherein n represents at least one selected order of differentiation. A distortion identifier is configured to compare at least one amplitude of the at least one determined locus against at least one selected reference locus, and to identify at least one distortion in the signal when the comparison indicates at least one selected exception condition.

Abstract: An optical accelerometer, gravitometer, and gradiometer have a light source, a beam splitter, a light medium, and a plurality of mirrors. The light beam from the light source is split into two beams that counter-propagate through the accelerometer. The acceleration experienced by the accelerometer causes a phase shift in the beams, and this phase shift is used to calculate the acceleration.

Abstract: An optical switch has a conductor and one or more sub-wavelength apertures. The switch is activated and periodic perturbations are dynamically formed in proximity to the conductor. Photons are directed toward and impinge upon the switch, and a greater amount of light propagates through the sub-wavelength apertures in the activated switch as compared to an unactivated switch.