Abstract: A window for utilization in the receiving of intelligence from a modulated beam of collimated light, with the window being configured to restrict the field of view of the optical system used therewith, and employing the phenomenon of total internal reflection. Such a window may be used to reject the entry of unwanted radiation, such as noise, and comprises first and second generally triangularly shaped wedges of optical material. The entry face of the first wedge is generally perpendicular to a base plane, and its rear face is disposed at an acute angle to the entry face. The entry face of the second wedge is disposed at the same angle to the base plane as the rear face of the first wedge, and the two wedges are separated by a small air gap.

Abstract: A transition between a waveguide and transmission line is disclosed in which a probe portion of the transmission line extends into the waveguide to electrically field couple signals between the waveguide and transmission line. The transmission line is preferably a coplanar fuse and includes a substrate having conductors disposed therein which prevent energy from propagating into the substrate from the waveguide. Propagation of energy into the desired transmission line mode is therefore facilitated. Because the probe is formed as an integral part of the transmission line, direct coupling to the waveguide is possible without the use of intervening sections, transitions or transmission lines. The transition may be scaled in order to couple a wide range of frequencies.

Abstract: A pliant, controllable contour control surface comprising a first flexible facesheet formed to a first initial contour of the control surface, and a second flexible facesheet formed to a second initial contour of the control surface. The first and second facesheets each have a set of prestrained shape memory alloy tendons embedded therein, extending from a leading edge to a trailing edge of the control surface. Each set of the shape memory alloy tendons is separately connected to a controlled source of electrical current such that tendons of the first and second flexible facesheets can be selectively heated in an antagonistic, slack-free relationship, to bring about a desired modification of the configuration of the control surface. A computer based control system is utilized for maintaining a constant temperature of the antagonists to establish conditions conducive to the stress induced transformation from austenite to martensite, accomplished by causing constant current to flow through the antagonists.

Abstract: A propulsion thruster (10) includes a solid-fuel, liquid-oxidizer main rocket engine (11), a tank (22) of liquid oxygen, and a turbine (32)-driven pump (30) for pumping liquid oxygen to the main engine. A solid-fuel, liquid-oxidizer auxiliary engine (40) has its oxidizer input port (50) coupled to the output (30b) of the turbopump, for generating drive fluids for the turbine (32) of the turbopump. The temperature of the turbine drive fluids is reduced to prevent damage to the turbine, and the mass flow rate is increased, by injecting water from a tank (60) into the drive fluids at the output (48) of the auxiliary engine (40). Starting is enhanced by preventing cooling of the solid fuel by the liquid oxidizer, which is accomplished by applying gaseous oxygen from a tank (90) to the oxidizer input port (50) of the auxiliary engine (40).

Abstract: A built-in-test capability is provided for determining the integrity of an optical fiber connecting: (a) an optical firing unit having a primary light source emitting a first wavelength, a test light source emitting a second wavelength different from the first wavelength, a mechanism both for coupling light from the light sources to the optical fiber and also for coupling the return light to a filter/detector; and (b) an optically initiated device which is coupled to a second end of the optical fiber. The apparatus includes a photoluminescent material disposed at a junction of the optically initiated device and the optical-fiber-second-end. This photoluminescence material photoluminesces at a third wavelength (when exposed to the test light source), and the light travels through the optical fiber and, when detected indicates optical fiber continuity.

Abstract: A vehicle includes a composite panel 10 with nonparallel face sheets 12,14, and a reinforcing core 16, preferably honeycomb, lying therebetween. A fastener 30 lies in an aperture 22 of the panel, and includes a socket 32 with a flange 40 bearing against first face sheet 12, and a body 46 defining a through aperture 54 and a spherical cavity 50. Fastener 30 also includes a swivel 34, with a ball-shaped knob 62 rigidly coupled to a post 64. Knob 62 fits into cavity 50 and can swivel. Post 64 is internally and externally threaded. An internally threaded spacer 36 is screwed onto the exterior threads 65 of post 64, to adjust the length of the fastener to the thickness of panel 10. Either post 64 or spacer 36 includes an additional fastening arrangement. In a particular embodiment of the invention, the additional fastening means of the spacer is a flange, and in another embodiment, it is a threaded portion of the bore of the post or of the spacer.

Abstract: This invention relates to new ceramic piezoelectric compositions having superior electrical properties, processes for the preparation of the new piezoelectric composition and applications for the new compositions. Specifically, a solid solution composition of 85.5-87.5 molar percent lead zinc niobate, 9.5-9.7 molar percent lead titanate and 3-5 molar percent of a barium titanate dopant or strontium titanate dopant has exhibited desirable electrical properties. This specific composition is well suited for use in a 3-1 connectivity composite, which can be used as a hydrophone. These compositions may be prepared by oxide sintering techniques utilizing extremely high purity materials, or alternatively, by a sol gel process.

Abstract: A device for converting a mid-wave infrared or long-wave infrared thermal image into a coherent near-infrared image includes a two-dimensional array of quantum-well-based optical modulators and infrared photodetectors. Each modulator is integrated or hybridized with a respective photodetector, and the combination is connected to an electronic circuit. Variations in mid-IR or long-IR light intensity are converted by each photodetector into variations in a bias applied to its respective modulator. The bias variations modulate the intensity and/or phase of near-IR light illuminating the modulators.

Abstract: A method for producing a stabilized magnesium hydroxide slurry comprising physically deflocculating the magnesium hydroxide solids in a starting slurry to produce a stabilized magnesium hydroxide slurry. Depending on the chloride level of the starting slurry, a cationic polymer may be added to the slurry. Optionally a thickening agent may be added to the deflocculated slurry. Also disclosed is a stabilized magnesium hydroxide slurry produced by the method which may be transported and stored without substantial agglomeration of the magnesium hydroxide solids.

Abstract: Weld filler alloys comprising aluminum, copper, lithium and, optionally, silver are disclosed which possess significantly improved fabricability and weldability. The weld filler alloys are free of magnesium and can be easily drawn into weld wire that is useful for welding aluminum-base alloys. Weldments made with the filler alloys exhibit highly improved mechanical, physical and corrosion resistance properties. The weld filler alloys may be used to weld cryogenic containers for space launch vehicles and the like.

Abstract: A stabilized, pressure-hydrated magnesium hydroxide slurry and a process for its production from burnt magnesite are described. According to an embodiment of the invention, a mixture comprising burnt natural magnesite and water is pressure hydrated to provide a pressure hydrated slurry. The pressure hydrated slurry is then deagglomerated. If desired, chloride ions and cationic polymer can be added to further stabilize the slurry.

Abstract: A device for remote sensing utilizing fiber optic techniques is presented. This device makes use of multi-mode optic fibers in conjunction with light polarized in multiple directions. The device presents a platform which is insensitive to phenomena outside of the remote sensing region while capable of detecting and analyzing multiple phenomena within the sensing region. The device is also capable of inspecting multiple remote sensing regions simultaneously.

Abstract: An optical sensor is described comprising a first optical fiber and a first reflective member. The first optical fiber has a first predetermined length of graded-index multimode optical fiber attached to its end. The first reflective member and the first optical fiber are arranged such that a gap is formed between the unattached end of the graded-index multimode optical fiber and the first reflective member. Also described is a rugged sensor design incorporating the first optical fiber and first reflective sensor as well as a method for providing the predetermined length of graded-index multimode fiber at the end of the first optical fiber. Finally, a readout system for an optical sensor is also described which comprises two optical paths differing in length by an amount equal to an optical path distance in the optical sensor. The readout system also comprises an optical source having a wavelength differing from that of the optical sensor, a modulator and a controller.

Abstract: An optical memory material includes a two-photon storage component which can be written from a first to a second state in response to WRITE light, mixed with a signal component which fluoresces by one-photon absorption only at the written locations in response to READ light. The storage material may be a fulgide. The memory material may also include a frequency upconversion material to aid writing. Writing is performed by a spatial light modulator (SLM) with a dynamic focussing system, for concentrating sufficient power at WRITE locations for nonlinear two-photon absorption. Crosstalk is avoided during simultaneous writing in some embodiments, by spacing the individual WRITE beams apart by an integer number of inter-beam spacings, so that non-adjacent datels are written simultaneously in a "paragraph," and the non-written areas are written at a different time with different paragraphs.

Abstract: A sparger system for mixing a solid/liquid suspension in a cylindrical container comprises a sparger pipe which extends substantially parallel to the longitudinal axis of the container. The sparger pipe is separated from an inner wall of the container by a first distance and a first end portion of the sparger pipe extends through a side wall of the container. A first flange member is releasably coupled to the first end portion of the sparger pipe so that, when the first flange member is coupled to the first end portion of the sparger pipe, the first end of the sparger pipe is sealed. The flange member may be removed from the first end portion of the sparger so that pressurized liquid may be introduced directly into the sparger pipe to clean the sparger pipe and the container. A fluid passage is coupled to the sparger pipe and extends to an opening which is above a maximum level of liquid to be stored in the container.

Abstract: Aluminum-base alloys containing Cu, Li, Zn and Mg are disclosed which possess highly desirable properties, such as relatively low density, high modulus, high strength/ductility combinations, strong natural aging response with and without prior cold work, and high artificially aged strength with and without prior cold work. In addition, the alloys possess good weldability, cryogenic properties, and elevated temperature properties. The alloys may comprise from about 3.5 to about 7 weight percent Cu, from about 0.1 to about 1.8 eight percent Li, from about 0.01 to about 4 weight percent Zn, from about 0.05 to about 3 weight percent Mg, from about 0.01 to about 2 weight percent grain refiner selected from Zr, Cr, Mn, Ti, Hf, V, Nb, B and TiB.sub.2, and the balance Al along with incidental impurities. Preferred alloys comprise from about 3.5 to 6.5 weight percent Cu, from about 0.5 to 1.8 weight percent Li, from about 0.3 to 2 weight percent Zn, from about 0.1 to 1.5 weight percent Mg, from about 0.05 to 0.

Abstract: A method is disclosed for the production of aluminum-copper-lithium alloys that exhibit improved strength and fracture toughness at cryogenic temperatures. Improved cryogenic properties are achieved by controlling the composition of the alloy, along with processing parameters such as the amount of cold-work and artificial aging. The ability to attain substantially equal or greater strength and fracture toughness at cryogenic temperature in comparison to room temperature allows for use of the alloys in cryogenic tanks for space launch vehicles and the like.

Abstract: A method for fabricating a hard faced fan blade containment system for turbofan aircraft engines, and the product resulting from that method. The product combines a hard facing material, a high strength fiber and an elastomeric binder to form a fan blade containment system which is lightweight and effectively retains fan blade fragments. The method consists of lightly bonding layers of high strength fibers together with a small amount of elastomeric binder so that they work in unison as a composite to contain a failed fan blade rather than as individual layers which are subject to sequential failure. In addition, a hard material such as ceramic or heat treated steel is encapsulated in an elastomer and bonded to the impact face of the containment system to blunt sharp edges of failed blade fragments and to spread the impact energy of the blade fragments over a larger area of the high strength fiber backing.

Abstract: Display devices incorporating an improved working electrode are disclosed. The devices comprise a transparent outer layer, a first electrode having a reflective surface facing the transparent layer, an electrochromic material located between the reflective surface and the outer transparent layer, an electrolyte in contact with the electrochromic material and a second electrode located behind the first electrode. The first electrode is ion-permeable, allowing ions to pass through and contact the electrochromic material in order to alter the optical properties of the material. The electrochromic material is preferably a conductive polymer such, as polyaniline. The display devices are capable of changing reflectance and/or color by the application of an electric potential to the electrodes.

Abstract: A semiconductor device having a metalized via hole used when mounting and connecting semiconductor chips, such as microwave chips, digital chips, analog chips and the like, on a top portion of a metalized carrier substrate is described herein. Each chip includes electrical circuitry on a top portion thereof with the circuitry connected to one end of a transmission line. Another end of the transmission line is connected to a metalized via hole. The via hole passes from the top portion of the chip to a bottom portion of the chip. The chip when mounted on the substrate is positioned over the top portion of the substrate and lowered thereon either by hand or with a mechanical chip carrying device. The bottom portion of the metalized via hole is indexed over a top of one end of a transmission line on the top portion of the substrate with the indexing tolerance between the two interfacing surfaces in a range of 0.5 to 10 mils.