Abstract: A control for a power source which includes nuclear fuel interspersed with thermionic converters, including a power regulator that maintains a substantially constant output voltage to a variable load, and a control circuit that drives a neutron flux regulator in accordance with the current supplied to the power regulator and the neutron flux density in the region of the converters. The control circuit generates a control signal which is the difference between the neutron flux density and a linear function of the current, and which drives the neutron regulator in a direction to decrease or increase the neutron flux according to the polarity of the control signal.

Abstract: Apparatus for the separation and extraction of molecular isotopes. Molecules of one and the same isotope are preferentially photo-dissociated by a laser and an ultra-violet source, or by multi-photon absorption of laser radiation. The resultant ions are confined with a magnetic field, moved in opposite directions by an electric field, extracted from the photo-dissociation region by means of screening and accelerating grids, and collected in ducts.

Abstract: A method and apparatus for recording directly group delay measurement of a system under temperature and stress tests employing a modulated carrier frequency swept over an S or X-band of interest and applied through a reference path and a test path to separate detectors for group delay measurement using a power divider, e.g., a directional coupler or a hybrid-T junction. A phase comparator is initially balanced, and then the modulated carrier is swept in frequency over the band of interest for different conditions of temperature and/or mechanical stress to obtain a family of characteristic group-delay curves for the system under test.

Abstract: An apparatus and method for removing and reinserting base member segments in an arcuate slot in an engine part where each base member separately includes blades or stators comprising holding the engine part in place while manipulating fingers on an arm into an interfitting abutting relationship with most of the blades on a base member and applying a torque force to the base of the blades to move a base member relative to such arcuate slot.

Abstract: A structure of a circularly polarized, thin conformal, antenna array which may be mounted integrally with the skin of an aircraft employs microstrip elliptical elements and interconnecting feed lines spaced from a circuit ground plane by a thin dielectric layer. The feed lines are impedance matched to the elliptical antenna elements by selecting a proper feedpoint inside the periphery of the elliptical antenna elements. Diodes connected between the feed lines and the ground plane rectify the microwave power, and microstrip filters (low pass) connected in series with the feed lines provide DC current to a microstrip bus. Low impedance matching strips are included between the elliptical elements and the rectifying and filtering elements.

Abstract: An improved apparatus for examining the crystal lattice of a semiconductor wafer utilizing x-ray diffraction techniques. The apparatus is employed in a method which includes the step of recording the image of a wafer supported in a bent configuration conforming to a compound curve, produced through the use of a vaccum chuck provided for an x-ray camera while the entire surface thereof is illuminated simultaneously by a beam of incident x-rays which are projected from a distant point-source and satisfy conditions of the Bragg Law for all points on the surface of the wafer.

Abstract: Fully annealed aluminum sheet is first stretch formed to the complex, doubly compound shape of a previously prepared forming die, e.g., an ejection seat blowout panel of a shuttlecraft. The part is then marked with a series of grid lines for monitoring later elongation. Thereafter it is solution heat treated and refrigerated to retard hardening. While still soft, it is stretched a second time on the same die to induce a modicum of work hardening, after which it is aged to the desired stress corrosion resistant temper, perferrably the T8 level, to provide the desired hardness and stress corrosion resistance.

Abstract: A flexible pile thermal barrier insulator includes a plurality of upstanding pile yarns. A generally planar backing section supports the upstanding pile yarns. The backing section includes a plurality of filler yarns forming a mesh in a first direction. A plurality of warp yarns are looped around said filler yarns and said pile yarns in said backing section and form a mesh in a second direction. A binder prevents separation of the yarns in the backing section.

Abstract: A closed cycle refrigeration (CCR) system is disclosed for providing cooling at different temperatures to different parts of a maser. The CCR includes a first station for cooling the maser's parts, except the amplifier portion, to 4.5.degree. K. The CCR further includes means with a 3.0.degree. K station for cooling the maser's amplifier to 3.0.degree. K and, thereby, increases the maser's gain and/or bandwidth by a significant factor. The means which provide the 3.0.degree. K cooling include a pressure regulator, heat exchangers, an expansion valve, and a vacuum pump, which coact to cause helium, provided from a compressor, to liquefy and thereafter expand so as to vaporize. The heat of vaporization for the helium is provided by the maser amplifier, which is thereby cooled to 3.0.degree. K.

Abstract: An externally moderated thermal nuclear reactor is disclosed which is designed to provide output power in the form of electromagnetic radiation. The reactor is a gaseous fueled nuclear cavity reactor device which can operate over wide ranges of temperature and pressure, and which includes the capability of processing and recycling waste products such as long-lived transuranium actinides. The primary output of the device may be in the form of coherent radiation, so that the reactor may be utilized as a self-critical nuclear pumped laser.

Abstract: Cermet compositions having high temperature oxidation resistance, high hardness and high abrasion and wear resistance, and particularly adapted for production of high temperature resistant cermet insulator bodies, comprising a sintered body of particles of a high temperature resistant metal or metal alloy, preferably molybdenum or tungsten particles, dispersed in and bonded to a solid solution formed of aluminum oxide and silicon nitride, and particularly a ternary solid solution formed of a mixture of aluminum oxide, silicon nitride and aluminum nitride. Also disclosed are novel ceramic compositions comprising a sintered solid solution of aluminum oxide, silicon nitride and aluminum nitride.The cermet compositions are designed particularly to provide high temperature resistant refractory coatings on metal substrates, preferably molybdenum or tungsten substrates.

Abstract: Flame retardant elastomeric compositions comprised of either spandex type polyurethane having incorporated into the polymer chain halogen containing polyols, conventional spandex type polyurethanes in physical admixture with flame retardant additives or fluoroelastomeric resins in physical admixture with flame retardant additives, methods of preparing fibers of the flame retardant elastomeric materials and articles of manufacture comprised of the flame retardant elastomeric materials and non-elastic materials such as polybenzimidazoles, fiberglass, nylons, etc.

Abstract: A wrist joint assembly is provided for use with a mechanical manipulator arm for finely positioning an end-effector carried by the wrist joint on the terminal end of the manipulator arm wherein the wrist joint assembly is pivotable about a first axis to produce a yaw motion, a second axis to produce a pitch motion, and a third axis to produce a roll motion, wherein the three axes are mutually perpendicular and have a common point of origin. The wrist joint assembly includes a disk segment affixed to the terminal end of the manipulator arm and a first housing member rotatably carried on the disk segment about the first axis. A second housing member is rotatably carried on the first housing member and a third housing member is rotatably carried on the second housing member whereby the third housing member and the mechanical end-effector carried thereon are moved in the yaw, pitch, and roll motion.

Abstract: Ceramic tantalum carbide artifacts having high thermal shock and mechanical erosion resistance are provided by incorporating tungsten-rhenium and carbon particles in a tantalum carbide matrix. The mix is sintered by hot pressing to form the ceramic article which has a high fracture strength relative to its elastic modulus and thus has an improved thermal shock and mechanical erosion resistance. The tantalum carbide is preferable less than minus 100 mesh, the carbon particles are preferable less than minus 100 mesh, and the tungsten-rhenium particles are preferable elongate, having a length to thickness ratio of at least 2/1. Tungsten-rhenium wire pieces are suitable as well as graphite particles.

Abstract: A differential optoacoustic absorption detector employs two tapered cells in tandem or in parallel. When operating in tandem, two mirrors are used at one end remote from the source of the beam of light directed into one cell back through the other, and a lens to focus the light beam into the one cell at a principal focus half way between the reflecting mirror. Each cell is tapered to conform to the shape of the beam so that the volume of one is the same as for the other, and the volume of each receives maximum illumination. The axes of the cells are placed as close to each other as possible in order to connect a differential pressure detector to the cells with connecting passages of minimum length. An alternative arrangement employs a beam splitter and two lenses to operate the cells in parallel.

Abstract: An adjustable securing base has a surface radius of curvature which can be adjusted to support an adjacent part on the base surface. The securing base comprises a flexible thin plate with an adjustment mechanism connected on opposite edges of the base for adjusting the plate curvature. An opening in the plate is coupled to a vacuum device for securing the part adjacent the plate surface.

Abstract: A method of adhering bone to the surface of a rigid substrate such as a metal or resin prosthesis using an improved surgical bone cement. The bone cement has mechanical properties more nearly matched to those of animal bone and thermal curing characteristics which result in less traumatization of body tissues and comprises a dispersion of short high modulus graphite fibers within a bonder composition including polymer dissolved in reactive monomer such as polymethylmethacrylate dissolved in methylmethacrylate monomer.

Abstract: A motion-restraining device for dissipating at a controlled rate the force of a moving body. The device is characterized by a drive shaft adapted to be driven in rotation by a moving body connected thereto through a tape wound about a reel mounted on the drive shaft, oscillatable mass, a crankshaft connected with the drive shaft, and an elongated pitman link having one end pivotally connected to the crankshaft and the opposite end thereof connected with the mass through an energy dissipating linkage including a shuttle disposed within a slot and guided thereby for rectilinear motion between a pair of spaced impact surfaces so configured that reaction forces applied at impact of the shuttle with the impact surfaces include oppositely projected force components angularly related to the direction of the applied impact forces, whereby a cancellation of components of reaction forces is achieved.

Abstract: This invention is a device for measuring small differences between relatively high sound pressure levels at two different microphone sites. It provides electrical insertion voltages, "pilot" voltages, as a means for continuously monitoring the gains of two acoustical channels. The difference between two pilot voltages is utilized to force the gain of one channel to track the other channel.

Abstract: A system for synchronizing a signal at a remotely located slave station with the phase and frequency of a signal generated at a master station. The signal transmitted at the master station and received by the slave station provides compensation for the phase shift caused by the transmission path delays between the master and slave station. The slave station transmits a signal to the master station at a frequency that is different from the frequency of the signal being transmitted by the master station. The signal transmitted by the slave station is received by the master station while the master station transmitter is off. The signal transmitted by the master station is received by the slave station while the slave station transmitter is off.