Abstract: Apparatus and method for producing maps of thickness or elastic constant iations of nominally plane sheet or plate materials. Amplitude variation at a set frequency on a normal resonance peak is recorded to determine resonance peak variation and thus specimen thickness or elastic constant variation. A mechanical scanner moves a transducer across the material submerged in a water tank for performing an ultrasonic C-scan. A transmitter or pulse generator repeatedly pulses the transducer to produce a focused narrow pulse of ultrasound which reverberates within the material. Echoes from the material in response to the pulse are received by the same or another synchronously moving transducer, whose resulting signal then passes through a gate, which removes extraneous signals and selects the number of multiple echoes and thus amplitude range desired, and a variable filter controlled by a function generator which selects the desired frequency, to a pen recorder.

Abstract: A method for preparing distortion-compensated images on film reticles for e in a plural optical projector readout unit. An oversized matrix of the images is prepared with each legend proportionately positioned in the field of view corresponding to one of the plural optical projectors. A very short focal length lens having one surface flat and the other convex is placed over the matrix with the flat surface adjacent thereto. The images, distorted through the lens, is photographed to produce a film reticle in a size suitable for use in the readout unit. The spherical aberration induced by the lens closely approximates the barrel distortion from the off-axis projection and magnification in the readout unit. In this manner, the image projected on the screen from the film reticle proportionately corresponds to the images in the matrix.

Abstract: A gas generator which separates a gas such as oxygen from a gas mixture such as air using a sorbent process. A sorbent contained in a fixed cooled bed absorbs the gas from the mixture; simultaneously a second bed of sorbent which previously absorbed the gas is heated and the gas is thereby desorbed from the sorbent. After a given time, the functions of the beds are exchanged. Heating and cooling of the two sorbent beds is accomplished by means of coolant which passes through each bed. Immediately after the functions of the beds are switched, the cool coolant first flows through and cools the absorbing bed, then is valved to a pump and to the heater for heating and then is valved to heat the second sorbent bed before being valved to a cooler for cooling.

Abstract: A coating composition for protecting metal surfaces from corrosion having ntrolled proportions of an alkyl ammonium alkyl phosphate and a high molecular weight petroleum sulfonate to inhibit corrosion, silicone and silicone alkyd resins to provide a physical barrier, trichlorotrifluoroethane and an aromatic hydrocarbon as solvents, and isopropyl alcohol as a coupling agent. An ethyl cellulose thickener may be added to the composition to increase its viscosity and reduce vertical run-off of the coating. The composition displaces water and moisture on the surface to be coated and deposits a clear, flexible, non-tacky film particularly resistant to abrasion.

Abstract: The novel prostaglandins PGB.sub.x are useful for a wide variety of in vivo and in vitro biological properties, including the reversal of degenerative changes in mitochondria, the protection of the heart against cardiac insults, the protection and reversal of anoxic damage to the brain, and the improvement of mammalian performance for conditioned psychological tasks. These prostaglandins PGB.sub.x are prepared, for example, by the base catalyzed reaction of PGB.sub.1.

Abstract: A laser device for generating high input power by minimization of surface flection losses between adjacent elements of the device. A laser medium having an index of refraction substantially greater than 1.5 is fluid cooled in a sealed tube by an optically clear cooling medium having a substantially lower refractive index. The indices of the laser and cooling mediums are matched to each other by thin film coatings of index matching material attached to the laser medium, each coating having a thickness of one quarter of the lasing wavelength.

Abstract: A signal enhancement method and apparatus including a computer arranged to process underwater signals at discrete spectral intervals for facilitating spectral signature recognition of submarines. An average of the spectral intensities of broadband noise on either side of the discrete spectral interval is computed and then subtracted from the spectral intensities of the specific narrow-band frequencies generated by the submarine, thereby eliminating any false combinations of nonrandom sidebands with random background noise. The remainder is then integrated with time producing a continuously increasing cumulative energy level of the discrete spectral interval when the energy thereof is originating from the submarine.

Abstract: A mixture of nondeuterated and partially or fully deuterated hydrocarbon ricants. Such a mixture exhibits substantially improved bearing performance life and oxidation resistance, without having fully deuterated the entire lubricant.

Abstract: A deployable stowed rotor having a rotor hub to which a pair of telescoping otor blades are connected is foldable into a package suitable for stowage prior to use. When the rotor is deployed, for example, as a lifting device for an ejection seat, positive preconing of the blades is provided by a spreading link arrangement connected to a drogue chute. Further coning during rotor spin-up is synchronized by intermeshed gears provided at respective one ends of the blades attached to the hub by teeter link hinges. Rotor speed is automatically regulated by a governing spring formed in conjunction with a helical spline arrangement between each of the blades and the hub and which varies the pitch of the spinning blades according to rotational velocity.

Abstract: A device for disconnectably linking a plurality of force producing or recing means such as a mechanical control system. The device comprises a coaxial array of a plurality of positive locking clutches, each clutch including two clutch halves. A single shaft passing through all clutch halves disengages and engages all clutches together as a motor connected thereto is actuated. The shaft is fail-safe spring loaded to the disengaged position, so that the spring will disengage all clutches if there is a power or motor failure.

Abstract: 1. A pulsed repeater amplifier circuit comprising three traveling wave tu, each said tube having a helical coil disposed therewithin; an input antenna; an output antenna; means connecting the said antennas and the said tubes in cascade so that a wave received on the input antenna is conducted successively through the said three tubes to the output antenna; means for establishing a predetermined electrostatic field about the helical coil in each tube; and means responsive to an individual modulating signal on the control grid of each tube for amplifying the wave during perdetermined intervals as it travels through each tube.

Abstract: A sonobuoy having a directional hydrophone centrally enclosed in a flexib acoustically transparent, spherical bag which upon deployment is filled with water to form a hydrosphere. A first embodiment comprises a plurality of upper and lower spreaders which form the bag into a spherical shape having a valve at the bottom most portion thereof for entry of water into the bag during oscillatory motion of the hydrophone. A second embodiment comprises a flexible, acoustically transparent, spherical bag which is time-filled with water by a pump to inflate the bag to a predetermined pressure. The hydrosphere forms a large virtual mass of static water around the hydrophone which reduces near field affects due to flow and motion noise and which also operates as a sea anchor.

Abstract: A deployable stowed rotor having a rotor hub to which a pair of telescoping otor blades are connected is foldable into a package suitable for stowage prior to use. When the rotor is deployed, for example, as a lifting device for an ejection seat, positive preconing of the blades is provided by a spreading link arrangement connected to a drogue chute. Further coning during rotor spin-up is synchronized by intermeshed gears provided at respective one ends of the blades attached to the hub by teeter link hinges. Rotor speed is automatically regulated by a governing spring formed in conjunction with a helical spline arrangement between each of the blades and the hub and which varies the pitch of the spinning blades according to rotational velocity.

Abstract: An object detection system capable of receiving and processing an omnidirional signal and two directional signals to produce a digitized omnidirectional signal, and digitized directional signals which have been corrected to magnetic north. The directional hydrophones produce sin .theta. and cos .theta. signals, where .theta. is the bearing angle of the sensed target from the directional hydrophones' y-axis. Each of the three signals is picked up by a separate hydrophone and is passed through an associated preamplifier and a shaper amplifier and low pass filter before being simultaneously sampled by separate sample/hold circuits. The three sampled signals are multiplexed to an analog to digital converter. The signal produced by a digital magnetic compass is converted to sin .theta. and cos .theta. values by appropriate function generators, where .theta. is the angle between the y-axis and magnetic north. The digital sin .theta., cos .theta., sin .phi. and cos .phi.

Abstract: A contour mapping system including compensation for the heave or vertical displacement of a ship due to wave and swell effects, and for correcting errors due to such effects in depth or bottom contour measurements of a body of water. Vertical acceleration A(s) of the ship, measured by a gravity meter accelerometer, is filtered according to the following Laplace transform equation by a cascaded series of filters to yield ship vertical displacement .DELTA.D(s) due solely to heave: ##EQU1## WHERE: .tau..sub.G = GRAVITY METER FILTER BREAKPOINT.omega..sub.f = filter transfer function breakpoint frequency.zeta. = filter transfer function damping constant.tau..sub.f = filter transfer function cut-off breakpointThis series of filters accomplishes attenuation of noise, such as is caused by gravity, vertical coriolis, vertical vibration or electrical noise, in the acceleration signal, and double integration of the remaining acceleration signal.

Abstract: A coating which is both a flexible sealant and a corrosion-inhibitive primer which can be used to protect the exterior skin and fastener patterns of high performance aircraft at low temperatures. The coating includes corrosion inhibitive pigmentation, resins, a curing agent, and a solvent blend permitting spray application of the coating. The two resins included in the coating are a reaction product of an epichlorohydrin and bisphenol A plus a polyurethane elastomer which is a reaction product of an aromatic isocyanate and a polyether glycol. The curing agent is a blocked diamine, i.e., a ketimine. The ketimine can be prepared by reacting a carbonyl compound and an aromatic diamine. Water is produced in this reaction. The reaction is reversible, so that as the ketimine absorbs atmospheric moisture, the aromatic diamine is released and in turn cures or cross-links the resins.

Abstract: A custom fitted pilot's helmet includes a liner attached within the confi of a helmet shell having numerous pressure relief holes over its entire surface. The liner includes a flexible sheet on one side of which is formed a plurality of elastic cell pairs separated by permanent heat seals or partitions overlaid with air tubes. The cells within a cell pair are separated from each other by a removable partition or severable heat seal. One cell of the cell pair contains one component of a foamable mixture and the other cell of the cell pair contains the second component of the foamable mixture. The liner-shell combination is positioned on the pilot's heat and the removable cell partitions are all virtually simultaneously removed. Thereafter, the foaming components within the cells admix and foam in situ to form a custom fitted helmet liner.

Abstract: A narrow angle, narrow bandwidth optical receiver system for detecting light rays reflected from a predetermined area illuminated by a laser beam having a known wavelength. A large collecting lens having a small field of view receives incoming reflected rays which are collimated by a pair of relay lenses having a narrow bandwidth, triple cavity, single element interference filter positoned therebetween. The filtered rays are processed by a photomultiplier tube and a CRT display to illustrate signals of interest within the illuminated area. An alternate embodiment provides a cone element to receive filtered rays from relay lenses for decreasing the size of the receiver system.

Abstract: A heat transfer device comprising a spiral brush insert within a tube of rmally conductive material. The brush insert has a diameter slightly larger than the inside diameter of the tube and is inserted from the downstream end of the tube so that the tips of the brush deflect to form a friction fit for imbedding within the tube wall and thereby prevent movement of the brush insert during normal fluid flow in the device.

Abstract: A mini-boat having an inflatable, hollow configuration for safely supporting persons in water. Two similarly shaped sheets of inflatable material are sealed together near their peripheral edges thereby forming two mirror imaged sections about an axis of symmetry at the stern of the mini-boat, the maximum depth preferably being near the axis and the sections tapering downwardly toward their distal ends at the bow. The sheets are further seamed together along a plurality of lines so spaced within the sealed sections as to define an array of relatively narrow interconnecting inflation cells. The sections are then folded at the axis and the opposing lower and distal edges are sealed together to define the keel and bow of the hull.