Abstract: A peripheral sliding seal for sealing the liquid propellant in a cylindrical tank 10 containing a piston 14 for positive expulsion of the liquid propellant. The seal comprises a peripheral inward flange member 16 around the piston periphery adjacent the inner wall of the tank, an annular pressure ring 18 bonded to the flange member 16 and forming several recesses therewith, one recess containing a compliant sealing ring 20 and the other containing a shear seal 32 bonded both to the flange member 16 and to the entrance head 12 of the tank. The bonds prevent internal and external leakage of the liquid fuel during storage. Pressurization of the piston 14 permits the piston 14 to move and breaks the shear seal 32. The compliant-ring seal slides with the piston 14, the compliant ring 20 being pressed against the inner wall of the tank by resilient fingers 34 of the pressure ring 18 to form a sliding seal.

Abstract: Actinides metals are recovered from spent nuclear fuel oxides containing fission products by a pyrochemical process. The process comprises, in part, electrorefining the metal complex from an anode by electrolytically oxidizing actinides into a salt and then electrodepositing actinides onto a cathode to form an actinide metal deposit. The actinide metal deposit is then melted to separate the salts and the actinide metals. The separated salt is recycled into an electrorefiner and the actinide metals are recovered and then transferred to a fuel fabrication system.

Abstract: A nonintrusive flow sensing system (10) and related method are provided for monitoring fluid flow within a conduit (14), particularly such as a liquid flow (12). The sensing system (10) includes an array of ultrasonic transducers (18, 20, 24, 26) mounted on the conduit (14) and adapted to send and receive pulsed ultrasonic signals bidirectionally across the conduit with an upstream-downstream component of direction, and through the conduit in longitudinal and circumferential directions. Signal transit times are processed to obtain accurate measurements of liquid flow velocity, temperature and pressure.

Abstract: To decrease the wear between the journal 6, and the hydrostatic bearing 1, especially during start up and shut down of the turbomachine, a rub ring 5, is employed intermediate the journal and bearing. The rub ring will come into contact with the journal before the bearing and prevent contact with the bearing bore. The rub ring also serves to block the leakage of the fluid from the bearing. This interrupted flow causes an increase in the stiffness and damping coefficients of the hydrostatic bearing. The use of the rub ring increases the life of the bearing, improves the rotordynamic performance, reduces the leakage flow and improves the hydrodynamic performance of the hydrostatic bearing.

Abstract: A light weight, efficient, and compact piezoelectric rotary union system is provided for joining structures such as space station modules. The system comprises piezoelectric actuators attached to a first structure that engage and rotate a ring attached to a second structure. The actuators position and rotate the ring by non-sliding, smooth walking motion that provides high mechanical efficiency, long life, and negligible electrical noise. Electrical conductors embedded in the ring and the actuator traction surfaces transmit electric currents and signals between the structures. Moderate traction pressure and large contact area substantially eliminate contact heating and associated vacuum welding. The piezoelectric actuators generate relatively large translational forces at relatively low speeds. The absence of conventional rolling bearings eases connection and disconnection of the rotary union.

Abstract: The invention relates to a device for accurately positioning an object, such as a mirror 3 used to precisely aim a laser. The invention uses kinematic principles to hold the object. Here a 2-2-2 kinematic bipod system is employed. The invention uses three actuators 5 to position the object. Each actuator acts as a bipod restricting the object in two of its six degrees of freedom. Each actuator has three degrees of freedom it can transmit to the object. The actuator can rotate on its single-axis flexure 7 so that the actuator cna rotate on one axis relative to support 4. Each actuator has a two-axis coincident flexure 8 on one end for allowing the object to be moved in two rotational degrees of freedom and the roller sleeve 50 allows a third rotational degree of freedom. Each actuator is positioned circumferencially about the central coordinate axis of the object to be moved, 120 degrees apart.

Abstract: An improved leak detection system (10) of the differential absorption type is provided for identifying gas leaks in a test object (12), wherein the improved system (10) provides enhanced resolution and accuracy by compensating for the effects of background gases and the like along the image path. The system utilizes a video camera (18) to generate images of the test object (12) which has been pressurized with a selected gas (14) having strong absorption properties with respect to an illuminating light source (16) of a selected wavelength. Since the absorption bandwidth of the test gas (14) varies with temperature, the gas is preconditioned as by heating such that the temperature of gas leaking to the exterior of the test object (12) will vary with proximity to the test object.

Abstract: An improved face seal assembly (10) is provided to prevent fluid leakage between assembled structural components (12), (14) or the like, such as housing components of a fluid control valve or the like. The face seal assembly (10) comprises a metal seal ring (16) defined by a rigid seal base (22) having generally parallel axial side faces (24), in combination with a pair of deflectable seal legs (26) extending generally radially from the seal base as axially diverging continuation of said side faces. The seal ring (16) is sandwiched coaxially between a pair of film gaskets (18) of a selected seal material, preferably such as a Teflon coated polyimide film. The resultant seal ring and gasket stack forms the face seal assembly (10) and is interposed between assembled housing components or the like to deflect the seal legs (26) toward each other into substantially coplanar relation with the axial side faces (24) of the seal base (22).

Abstract: A thrust engine is disclosed in the form of a hybrid staged combustion-expander topping cycle engine. The engine comprises a mixed cycle, one cycle being an expander cycle (14) operating at low temperatures and the other being a staged combustion cycle (12) operating at a higher temperature. A portion of liquid hydrogen from a fuel pump (16) is passed in heat exchange relation with the engine nozzle (22) for cooling same and heating the hydrogen, and the heated hydrogen is passed to an oxidizer turbine (28) for driving a liquid oxygen pump (81). Another portion of the liquid hydrogen from the fuel pump is passed in heat exchange relation with the engine thrust chamber (21) and combustor (20), and a portion of the resulting heated hydrogen is introduced, together with a portion of the pressurized liquid oxygen from the liquid oxygen pump, into a preburner (20) for combustion therein, and passage of the combustion gasses to a fuel turbine (26) for driving the fuel pump.

Abstract: A castable smoke-producing pyrotechnic composition comprising a hydroxy-terminated azido polymer binder with a polyisocyanate curative, an energetic plasticizer, and a dye in an amount sufficient to generate colored smoke.

Abstract: An annular ring resonator which employs relay imaging to reduce crosstalk caused by diffusion which occurs between biconic mirrors 30 and 31 in the resonator.

Abstract: A warning device (10) is provided for use by electrical technicians or the like to indicate the presence of an electrical shock hazard. The warning device is adapted to be worn on the wrists or the like and includes a filtered detection circuit (32,34) for sensing a target signal such as an ac noise signal emitted from an electrical source. When the target signal magnitude exceeds a selected threshold (40), such as when the wearer moves into close proximity with the signal source, the warning device (10) activates an alarm (42,44) to indicate the presence of a shock hazard.

Abstract: A method for the densification of a shaped nickel base single crystal alloy article utilizing a pre-HIP, an improved hot isostatic pressing (HIP) step, and post-HIP solution heat treatment to enhance removal of casting porosity in a finished article.

Abstract: A device to provide high current, low emittance electron beams with a long life cathode. The device consists of an undulator 7 which provides a source of ultraviolet light 15 for an ultraviolet photocathode 8. The undulator 7 needs a supply of electrons to produce the ultraviolet light which it can get by diverting a portion of a beam from a linear accelerator 3 before E.sub.3 or after E.sub.4 the electron beam traverses a free electron laser 5. The device is self-maintaining once a source of electrons is developed but needs a start-up source of electrons. The start up source can be provided by a pulsed cathode electron gun 1 which has to be on for a short period of time until the ultraviolet photocathode 8 is operated.

Abstract: Glycidyl azide polymer esters for use in insensitive gun and rocket propellants having pendant terminated azide ester groups and a method for producing same.

Abstract: This invention relates to a fine focusing lens for charged particle beams. Since the field lines of the poles are additive, and the lens 50 can be made to be very small, the lens can be used inside of a coarse focusing lens 51. The lens 50 employs a plurality of poles 1-32, evenly spaced, circumferentially around the lens. The poles may be wires 38 for electromagnetic poles or plates 35 for electrostatic poles. Each pole can be tagged to induce a frequency, pulse, or phase signal on the charged particle beam 49, so that the effects of each pole on the beam can be separately detected. The beam can therefore be focused by seeing the effects of and adjusting each pole separately. As the number of poles increases, the ability to finely focus a charged particle beam increases. The lens 50 as shown in the figures has 32 poles, which is enough to very finely focus a charged particle beam.

Abstract: The present invention relates to an apparatus and method for steering a light beam which utilizes the relative positioning of adjacently disposed semi-spherical windows to provide the desired steering.

Abstract: A low freezing point eutectic solid propellant plasticizer composition component comprising a mixture of 1,5-dinitrato-3-nitrazapentane and 1,5-diazido-3-nitrazapentane having a eutectic freezing point below about -25.degree. C.

Abstract: Energetic azido curing agents are provided for curing hydroxy-terminated aliphatic polymers having pendant alkyl azide groups.

Abstract: An apparatus for treating a gas stream with a liquid includes a housing containing an eliminator section for removing liquid from the gas and, adjacent to and upstream of the eliminator section with respect to the gas flow, vertical angle liquid collectors mounted on side walls of the housing to remove from the gas stream large amounts of liquid which flow along the side walls. A plate member depends from a top wall of the housing and another plate member extends up from adjacent the bottom wall of the housing to deflect toward a central portion of the eliminator liquid-laden portions of the gas stream which travel along the top and bottom walls. Baffles upstream of the eliminator are adjustable to control the flow of gas through the apparatus. The eliminator includes a plurality of sawtooth blades defining zigzag paths for the gas, each blade including a plurality of planar members each having at least one vertical groove adjacent its trailing end to remove liquid from the gas and permit it to drain.