Abstract: An apparatus for cutting annular corrugations in an interior surface of a cylindrical tube having a cutter head comprising a plurality of cutting teeth; a drive shaft coupled to the cutter head for spinning the cutter head; a mandrel coupled to the cutter head, wherein the mandrel defines a longitudinal axis, wherein an axis of rotation of the cutter head is parallel to, but in a position not coaxial with the axis of rotation of the cutter head; an outer eccentric coupled to mandrel, wherein the outer eccentric rotates the mandrel, wherein the axis of rotation orbits around the longitudinal axis.

Abstract: Methods and systems are generally described that inhibit debris (such as ice) accretions and/or remove debris (such as ice) accretions from the exterior surface of an aircraft. In some embodiments, the invention is a system for an aircraft comprising: a component of the aircraft having a surface; a plurality of piezo-kinetic actuators each positioned proximate to a portion of the surface; and a control unit coupled to the plurality of actuators, the control unit configured to actuate one or more of the actuators at one or more frequencies; wherein the actuators are each configured to introduce a displacement of the surface in three dimensions to inhibit a formation of ice on at least the portion of the surface and to break up existing ice formations on at least the portion of the surface.

Abstract: The present embodiments providing methods, systems and apparatuses of protecting a surface during laser machining. In some embodiments, a method of protecting a surface during laser machining comprises: directing a fluid into a cavity of an object being laser machined, where the fluid does not have laser absorption properties; and directing a plurality of laser pulses at a wall of the object being laser machined, where the laser pulses are configured to form a hole through the wall such that at least one laser pulse passes through the hole and enters the cavity while the fluid is directed into the cavity such that the laser pulse is incident on the fluid and a surface together in order to inhibit backwall damage.

Abstract: A modular, nuclear waste conversion reactor that continuously produces usable energy while converting U-238 and/or other fertile waste materials to fissionable nuclides. The reactor has a highly uniform, self-controlled, core (2) with a decades-long life and does not require reactivity control mechanisms within the boundary of the active core during operation to retain adequate safety. The exemplary embodiment employs high-temperature helium coolant, a dual-segment (22) initial annular critical core, carbide fuel, a fission product gas collection system, ceramic cladding and structural internals to create a modular reactor design that economically produces energy over multiple generations of reactor cores with only minimum addition of fertile material from one generation to the next.

Abstract: A modular, nuclear waste conversion reactor that continuously produces usable energy while converting U-238 and/or other fertile waste materials to fissionable nuclides. The reactor has a highly uniform, self-controlled, core (2) with a decades-long life and does not require reactivity control mechanisms within the boundary of the active core during operation to retain adequate safety. The exemplary embodiment employs high-temperature helium coolant, a dual-segment (22) initial annular critical core, carbide fuel, a fission product gas collection system, ceramic cladding and structural internals to create a modular reactor design that economically produces energy over multiple generations of reactor cores with only minimum addition of fertile material from one generation to the next.

Abstract: Some embodiments provide energy storage systems that comprise: a first electrode; a second electrode; an electrolyte; the first electrode, the second electrode and the electrolyte are positioned such that the electrolyte is in contact with at least the first electrode; and a polarity reversal system electrically coupled with the first electrode and the second electrode, wherein the polarity reversal system is configured to allow the energy storage system to operate while a first polarity to charge and discharge electrical energy while operating in the first polarity, and the polarity reversal system is configured to reverse the voltage polarity across the first and second electrodes to a second polarity to allow the energy storage system to continue to operate while the second polarity is established across the first electrode and the second electrode to continue to charge and discharge electrical energy while operating in the second polarity.

Abstract: Systems, devices and methods are disclosed for controlling the flow of a fluid over the window of an optical instrument housing in a freestream flow field. For example, the flow upstream of the housing may be split to create a flow region over the window that is conducive to successful operation of the instrument. The flow region may be maintained for various rotations of the housing about yaw, pitch, and roll axes. The disclosed features in some embodiments induce flow regions with reduced spatial and temporal density gradients of the flow over the window.

Abstract: Techniques, devices and systems use pseudo-conductor materials as antennas to receive or radiate electromagnetic energy for communications and other applications. Methods of configuring an antenna can include, in some implementations, selecting a pseudo-conductor material having an electromagnetic constitutive property, wherein the electromagnetic constitutive property comprises a real part of the electromagnetic constitutive property that is greater than a corresponding imaginary part of the electromagnetic constitutive property; and forming the pseudo-conductor material into an antenna shape configured, upon being excited, to radiate emissions that satisfy a predefined antenna performance, such that the pseudo-conductor material formed in the antenna shape weakly guides an electromagnetic wave on the pseudo-conductor material using a leaky mode that is below cutoff to establish a field structure to radiate the emissions from the pseudo-conductor material that satisfy the antenna performance.

Abstract: Methods and systems are generally described that inhibit debris (such as ice) accretions and/or remove debris (such as ice) accretions from the exterior surface of an aircraft. In some embodiments, the invention is a system for an aircraft comprising: a component of the aircraft having a surface; a plurality of piezo-kinetic actuators each positioned proximate to a portion of the surface; and a control unit coupled to the plurality of actuators, the control unit configured to actuate one or more of the actuators at one or more frequencies between about 1 Hz and about 1 kHz; wherein the actuators are each configured to introduce a displacement of the surface in three dimensions to inhibit a formation of ice on at least the portion of the surface and to break up existing ice formations on at least the portion of the surface.

Abstract: A tritium production element for use in a conventional power reactor, and methods of use and making, are provided, wherein the element experiences reduced tritium permeation during irradiation by incorporating a silicon carbide barrier that encapsulates one or more burnable absorber pellets. The tritium production element includes a tubular cladding that encloses a plurality of burnable absorber pellets, such that individual pellets or groups of pellets are disposed within a silicon carbide barrier layer.

Abstract: A method for preparing plutonium-238 (Pu-238) includes using a nuclear reactor in irradiating a liquid containing a neptunium-237 (Np-237) based compound with neutrons to convert a portion of the Np-237 based compound to a Np-238 based compound; retaining the liquid containing the resulting mixture for a sufficient amount of time for the Np-238 based compound to at least partially convert to a Pu-238 based compound; and separating the Pu-238 based compound from the neptunium based compounds using fractional distillation or a chemical separation method.

Abstract: Embodiments of the present invention provide high durability joints between ceramic articles, particularly between beta-silicon carbide (?-SiC) articles, and methods of making and using the same. In one embodiment, a joint between first and second articles each comprising a ceramic polymorph comprises a matrix comprising the ceramic polymorph and extending between the first and second articles; a plurality of inclusions comprising the ceramic polymorph and being distributed throughout the matrix; and a sealing layer comprising the ceramic polymorph and being respectively disposed on the first and second articles and the matrix.

Abstract: Systems, devices and methods are disclosed for controlling the flow of a fluid over the window of an optical instrument housing in a freestream flow field. For example, the flow upstream of the housing may be split to create a flow region over the window that is conducive to successful operation of the instrument. The flow region may be maintained for various rotations of the housing about yaw, pitch, and roll axes. The disclosed features in some embodiments induce flow regions with reduced spatial and temporal density gradients of the flow over the window.

Abstract: Methods and apparatus are provided for producing and extracting Mo-99 and other radioisotopes from fission products that overcome the drawbacks of previously-known systems, especially the excessive generation of radioactive wastes, by providing gas-phase extraction of fission product radioisotopes from a nuclear fuel target using a mixture including halide and an oxygen-containing species with heat to convert the fission product radioisotopes to gas (e.g., Mo-99 to MoO2Cl2 gas). The gaseous species are evacuated to a recovery chamber where the radioisotopes solidify for subsequent processing, while the substantially intact uranium target made available for further irradiation and extraction cycles.

Abstract: Some embodiments provide interrupter systems comprising: a first electrode; a second electrode; a piston movably located at a first position and electrically coupled with the first and second electrodes establishing a closed state, the piston comprises an electrical conductor that couples with the first and second electrodes providing a conductive path; an electromagnetic launcher configured to, when activated, induce a magnetic field pulse causing the piston to move away from the electrical coupling with the first and second electrodes establishing an open circuit between the first and second electrodes; and a piston control system comprising a piston arresting system configured to control a deceleration of the piston following the movement of the piston induced by the electromagnetic launcher such that the piston is not in electrical contact with at least one of the first electrode and the second electrode when in the open state.

Abstract: A reflective coating is disclosed that has a base layer provided with a reflective surface for reflecting electromagnetic radiation, such as visible and solar near-infrared light. The reflective coating also has a dielectric layer formed on the reflective surface, and an absorber layer. The absorber layer is formed on the dielectric layer that is formed on the base layer. The reflective coating has an average reflectance greater than about 60% for wavelengths of electromagnetic radiation in the range of 800 to 2500 nm that is irradiated upon the reflective coating. Additionally, the reflective coating has an average reflectance for wavelengths of electromagnetic radiation in the range of 400 to 700 nm irradiated upon the reflecting coating that is less than the average reflectance of the reflective coating from 800 to 2500 nm.

Abstract: A device for generating a pulsed flow in a channel containing a circulating algal culture can include a plate that is pivotably mounted on the channel and an activator. A pulsed flow is generated in the channel by first positioning the plate to impede the flow of circulating algal culture and then rotating the plate to a submerged position. The pulsed flow can be employed to counteract the negative effects of bio-fouling on algae cultivation equipment. In another arrangement, a device for generating a pulsed flow in a sloped raceway that is in fluid communication with a sump can include a gate. In different embodiments, the gate can operate as a so-called “pinch gate” or as a so-called “overflow gate.” In another aspect, a variable rate pump, such as a centrifugal pump, a screw pump or an airlift pump, is described for establishing a pulsed flow in a channel.

Abstract: Some embodiments provide an amplifier apparatus, comprising: a plurality of amplifier transistor circuits coupled in series, wherein each of the plurality of amplifier transistor circuits comprises: a transistor, wherein the transistors of the plurality of amplifier transistor circuits are coupled in series; a transistor voltage control and drive circuit coupled with the corresponding transistor, wherein the transistor voltage control and drive circuit is configured to control and drive the corresponding transistor in accordance with received control signals and in parallel with the other of the plurality of amplifier transistor circuits; and isolation circuitry that isolates control of the transistor from control of the other of the amplifier transistor circuits; wherein the plurality of amplifier transistor circuits are configured to be controlled and driven in parallel relative to the control signals.

Abstract: Techniques, devices and systems use pseudo-conductor materials as antennas to receive or radiate electromagnetic energy for communications and other applications. Methods of configuring an antenna can include, in some implementations, selecting a pseudo-conductor material having an electromagnetic constitutive property, wherein the electromagnetic constitutive property comprises a real part of the electromagnetic constitutive property that is greater than a corresponding imaginary part of the electromagnetic constitutive property; and forming the pseudo-conductor material into an antenna shape configured, upon being excited, to radiate emissions that satisfy a predefined antenna performance, such that the pseudo-conductor material formed in the antenna shape weakly guides an electromagnetic wave on the pseudo-conductor material using a leaky mode that is below cutoff to establish a field structure to radiate the emissions from the pseudo-conductor material that satisfy the antenna performance.

Abstract: A variable permeability antenna apparatus includes a first region configured for coupling with a feed of a radio frequency signal and a second region for transmitting the radio frequency signal. The permeability of material at the second region is greater than the permeability of material at the first region. Also, a spiral antenna for transmission or reception of radio frequency signals is disclosed.