Abstract: A control rod for a nuclear reactor incorporates a plurality of neutron absorber tubes containing neutron absorbing materials. The absorber tubes are substantially rectangular inside and outside, each tube containing at least one axial stack of substantially round neutron absorbing material segments or capsules.

Abstract: A circuit breaker thermal-magnetic trip unit for arcing fault detection includes a current transformer having a gapped magnetic core arranged around the load side of the trip unit. The bimetal within the trip unit is positioned abutment with the gap in the transformer core to thereby heat the bimetal causing the bimetal to trip and separate the circuit breaker contacts.

Abstract: Persistent compressive stresses sufficient to suppress hot cracking, reheat cracking and stress corrosion cracking are developed in welds containing alloys of plural materials by quenching of the weld after onset of solidification but while the weld remains soft or "mushy" at a temperature above the melting point of eutectic alloys which may form. Control of the time of quenching is preferably established during submerged welding by a cup-shaped exclusion fitting which is sized relative to the dimensions of a molten weld pool and the speed of travel of a welding heat source such as a plasma transfer arc torch. The cup-shaped exclusion fitting provides improved protection of the weld and heat source with inert gas supplied thereto while also permitting submerged welding at higher hydrostatic pressures than has heretofore been possible.

Abstract: A nickel-base superalloy article has a coating having a composition, in weight percent, of from about 10 to about 20 percent cobalt, from about 14 to about 25 percent chromium, from about 2 to about 12 percent aluminum, from 0 to about 0.2 percent yttrium, from about 0.001 to about 3 percent boron, from about 1 to about 10 percent silicon, balance nickel and incidental impurities. The coating is preferably applied by mixing together two powders, one with a higher solidus temperature and one with a lower solidus temperature, whose net composition is that of the coating. The powder mixture is compacted with a binder, applied to a surface of the article, and heated to a temperature above the lower solidus temperature.

Abstract: A low pressure discharge lamp, particularly a compact fluorescent lamp, achieves an overall reduction in height by orienting ends of the envelope radially inward for connection to the base. This advantageously positions the electrodes housed within the envelope away from the base. Moreover, this mounting arrangement provides resistance against pull out forces and elimination of a cement to secure the envelope to the base, as well as other improved heat transfer benefits.

Abstract: An improved process for the purification of solid dihydric phenol, preferably bisphenol-A recovered from a polymer containing the reaction residue of dihydric phenol units in the polymer structure by essentially dry distilling dihydric phenol in the presence of about 0.005 to about 0.05 weight percent of hypophosphorous acid based on the weight of dihydric phenol.

Abstract: First and second flexible interconnect structures are provided and each includes a flexible interconnect layer and a chip with a surface having chip pads attached to the flexible interconnect layer. Molding material is inserted between the flexible interconnect layers for encapsulating the respective chips. Vias in the flexible interconnect layers are formed to extend to selected chip pads, and a pattern of electrical conductors is applied which extends over the flexible interconnect layers and into the vias to couple selected ones of the chip pads.

Abstract: A cryogen recondensing system magnetic resonance imager superconducting magnet and a cryogen recondensing system with a rare earth displacement material cryocooler and superconductive lead bismuth magnetic sleeve provides superconducting current flow of currents induced by movement of the rare earth displacer which generate opposing magnetic fields to shield the superconducting magnet from the magnetic interference of the cryocooler rare earth displacer. Strips of high conductivity wave-shaped aluminum or sapphire rods may be embedded in the surface of the sleeve to lower the thermal resistance of the superconducting shield to enable it to quickly reach superconducting temperature.

Abstract: This invention provides an improved process of preparing UO.sub.2 powder from poor quality, partially oxidized powder containing organic and inorganic impurities. The process is illustrated in the flow chart of FIG. 1 which includes the steps of (a) oxidizing a uranium-containing scrap also containing inorganic and cationic organic impurities; (b) solubilizing, typically with nitric acid, the uranium contained in the oxidized scrap to produce uranyl nitrate; (c) solvent extracting the solubilized product of step (b) to remove cation impurities to provide a purified uranyl nitrate solution; (d) precipitating the purified uranyl nitrate with ammonia to form ammonium diuranate powder; and (e) calcining and passivating the ammonium diuranate powder to produce UO.sub.2 powder; and optionally (f) forming the UO.sub.2 powder of step (e) into pellets and sintering the formed pellets to produce sintered UO.sub.2 pellets.

Abstract: An indium gasket having a configuration which allows the indium to reach its yield point at a relatively low contact pressure. The indium gasket is provided with a multiplicity of openings which are filled by the deforming indium during compression between the cryocooler and the cryocooler interface sleeve of a superconducting magnet system. The creation of openings in the gasket has the effect of decreasing the mechanical interface pressure at which the indium yields. The indium flows at a mechanical interface pressure that does not exceed the structural strength requirements of the cryocooler. The indium flows into the empty spaces formed by the openings, thereby providing the necessary thermal conductance between the cryocooler and the interface sleeve. The result is a relatively small temperature difference between the interface sleeve and the cryocooler during cooling of the superconducting magnets.

Abstract: Disclosed is a ballast circuit for a gas discharge lamp, including a resonant load circuit with a gas discharge lamp and first and second resonant impedances whose values determine the operating frequency of the resonant load circuit. The ballast circuit further includes a d.c.-to-a.c. converter circuit coupled to the resonant load circuit so as to induce an a.c. current in the resonant load circuit. The converter circuit comprises first and second switches serially connected between a bus conductor at a d.c. voltage and ground, and has a common node through which the bidirectional load current flows. A feedback arrangement regeneratively controls the first and second switches, and includes a circuit for sensing a.c. current in the resonant load circuit and producing a feedback signal in proportion to the a.c. current.

Abstract: A method for nondestructive/noncontact detection of alpha case on a surface of a workpiece made of titanium or a titanium-based alloy. Infrared radiation is reflected off of a selected portion of the workpiece surface and sensed by a detector which may comprise a scanning infrared radiometer, an infrared camera, or a spot radiometer. The presence of any alpha case in the selected portion of the workpiece surface is detected by comparing the intensity of the reflected infrared radiation to a predetermined intensity known to be indicative of the absence of alpha case. An image of the reflected infrared radiation may be created and the step of detecting the presence of alpha case may include the step of comparing the intensity of the reflected infrared radiation within the image to the predetermined intensity. According to a preferred embodiment, a target may be disposed between the source of the infrared radiation and the workpiece surface so as to create a predetermined pattern within the image.

Abstract: A neutron radiography camera operates in cooperation with a neutron beam source for determining hydrogen content of irradiated BWR fuel elements. The camera implements the method using a notched neutron spectrum filter to determine the hydrogen content. The camera is specifically configured to take advantage of the tubular geometry of a nuclear fuel rod. Incident neutron beam ports are formed in a base unit that receives an incident filtered neutron beam. The ports aim the neutron beam at a periphery of the BWR fuel elements, which in the context of nuclear fuel rods includes zirconium alloy cladding. Collision of the neutrons with hydrogen in the cladding lowers their energy and scatters them at preferential angles. Scatter cavities defining scattered neutron paths are formed in the base unit, and absorber plates are disposed of terminal ends of the scatter cavities. The absorber plates become activated by resonance absorption from the neutrons scattered by hydrogen in the target fuel elements.

Abstract: A combustor mount joins a mounting arm of a combustor to a conical nozzle support of a turbine nozzle. The mounting arm includes a conical mounting flange having first and second axially spaced apart radial lands and a plurality of circumferentially spaced apart outer holes. The nozzle support includes a conical seat having first and second axially spaced apart radial rabbets and a plurality of circumferentially spaced apart inner holes. The first and second lands are disposed on respective ones of the first and second rabbets, with the outer and inner holes being aligned. A plurality of fasteners extend through respective pairs of the aligned holes for clamping together the mounting flange to the seat to mount the combustor to the nozzle support.

Abstract: Disclosed is a fluorescent lamp and ballast arrangement of the type having a lamp base for connection to a fixture that also accommodates a lamp base of an incandescent lamp. A ballast circuit contains a first conversion circuit which converts a.c. voltage to d.c. voltage and which has an electrolytic capacitor for smoothing the d.c. voltage. The ballast circuit further includes a second conversion circuit which converts the d.c. voltage into a.c. current and which includes a resonant inductor and resonant capacitor. A ballast housing has first and second ends spaced along a longitudinal axis of the housing and encloses parts of the ballast circuit. Only two lamp tube portions of the lamp terminate in the first end of the ballast housing, with the resonant inductor being positioned between the two lamp tube portions.

Abstract: A filament-heater power supply includes a combination forward and flyback power converter for supplying electronically variable, isolated voltages to dimmable discharge lamp filaments while supplying a fixed dc output voltage to a ballast control circuit. Hence, only a single ballast power supply is needed. The control circuit controls the level of filament voltage to operate the lamp filaments at an optimum temperature, even during dimming operation, thereby substantially extending lamp life. The filament-heater power supply provides a high degree of isolation among filament voltages while regulating and tracking the voltage across each filament. The filament-heater power supply can preheat the filaments to aid lamp starting, thereby extending the useful life of the lamp, and is also structured to sense when a lamp is not present in a fixture so that high voltage starting pulses are not applied to the terminals of an empty fixture.

Abstract: An actively controlled acoustic treatment panel for suppressing noise in a gas turbine engine nacelle including a backsheet formed by a planar matrix of adjacent individually controllable elements, where each of the controllable elements has a transducer and a honeycomb cell enclosing the transducer. A facesheet is also bonded to the controllable elements. A plurality of sensors are positioned within the acoustic treatment panel for sensing acoustic pressure of the noise propagated against the facesheet. A driver is provided for electrically driving each of the transducers to effect displacement thereof in a direction substantially perpendicular to the facesheet. Circuitry is also operatively connected to the pressure sensors and the driver for controlling velocity magnitude and phase of the transducers during displacement, wherein a resulting acoustic impedance at the facesheet achieves a desired acoustic impedance boundary condition at the nacelle.

Abstract: A field-installable circuit breaker trip actuator unit includes a flux shifter unit that interfaces with the circuit breaker operating mechanism and is installable without dismantling the circuit breaker components. The flux shifter unit responds to an electronic trip unit to articulate the circuit breaker operating mechanism and separate the circuit breaker contacts upon occurrence of an overcurrent condition. A reset arrangement allows the trip actuator unit to be automatically reset upon completion of the contact separation process.

Abstract: An exhaust nozzle of a gas turbine engine effective for reducing the emission of infrared radiation and providing an extensive maneuvering capability. The nozzle preferably is of the two-dimensional type and includes an exhaust cowl with a generally rectangular cross-sectional exhaust opening and a plug within the downstream end of the cowl. The plug, which is preferably wedge-shaped, is pivotable about a transverse axis running through the aft portion of the plug by an appropriate means, for example, a cam or a screw jack mechanism. The nozzle can also include blocker doors and louvers for providing thrust reversal.

Abstract: A ballast system for at least one dimmable fluorescent lamp includes a ballast inverter for driving the fluorescent lamp to provide light output and a parallel impedance for coupling across the fluorescent lamp for providing an alternative path for diverting sufficient ac current to avoid developing striated light output as the light output is dimmed. The parallel impedance may be a resistor connected in series with a diode. For multiple lamp systems, the parallel impedance may be connected across one or more of the lamps.