Abstract: Acetals of the formulas CHCl.sub.2 CH(OR).sub.2, CCl.sub.3 CH(OR).sub.2, .sub.2 CH(OR).sub.2, CF.sub.3 CH(OR).sub.2, RO.sub.2 CCH(OR).sub.2, and (RO).sub.2 HCCH(OR).sub.2 wherein R can be --CH.sub.2 CYZ(NO.sub.2), --CH.sub.2 CH.sub.2 CYZ(NO.sub.2), --CH.sub.2 C(N0.sub.2).sub.2 CH.sub.3, --CH.sub.2 C(NO.sub.2).sub.2 CYZ(NO.sub.2), --CH.sub.2 C(NO.sub.2).sub.2 CH.sub.2 CYZ(NO.sub.2) or --CH.sub.2 C(NO.sub.2).sub.2 C(NO.sub.2).sub.2 CYZ(NO.sub.2) wherein Y and Z vary independently and can be Cl, F or NO.sub.2. These acetals are produced by contacting a negatively substituted aldehyde such as CHCl.sub.2 CHO, CCl.sub.3 CHO, CHF.sub.2 CHO, CF.sub.3 CHO, HO.sub.2 CCHO, or OHCCHO with a negatively substitute alcohol of the formula ROH wherein R is as defined above. Either FSO.sub.3 H, ClSO.sub.3 H, or CHF.sub.2 SO.sub.3 H, or CF.sub.3 SO.sub.3 H is used to catalyze the condensation. The acetals of this invention are useful as explosives.

Abstract: An underwater noisemaking device that is self-driven for use in towed undater acoustic minesweeping or as a decoy countermeasure device. It comprises a cambered and slotted disc mounted in a frame so as to be free to rotate about a horizontal, transverse axis within its plane when being towed or is in a flow stream. The disc auto-rotates rapidly causing intermittent cavitation, resulting in the emission of loud "clapping" acoustic noise. It may be incorporated into other towed underwater acoustic minesweeping and decoy devices.

Abstract: The present invention determines the occurrence of leading and trailing es of a target under evaluation by an IFF system. A target's "leading edge" is declared when a predetermined number T.sub.L of correct replies is found to exist in a predetermined group of W.sub.L received replies in response to a number B of interrogations. A target's "trailing edge" is declared when a number T.sub.z of incorrect replies is found to exist in a group of W.sub.z replies if either at least a number B of interrogations have been transmitted after the target's "leading edge" has been declared, or a number T.sub.u of correct replies is found to exist in a group of W.sub.u received replies followed by reduction of this number T.sub.u to a smaller number T.sub.t.

Abstract: Synchronous plating techniques for reducing adjacent bit disturb charactetics or interactions in a magnetic memory wire include the step of sinusoidally and smoothly depositing the magnetic layer on the outer surface of the wire so as to increase the effective magnetic path length between adjacent bits. The resultant wire has changing cross-sectional dimensions corresponding to the varying sinusoidal configuration of the wire.This invention concerns a film-plated memory wire of improved characteristics and the method of making the same. The term "memory wire" is used to designate a magnetic recording and reproducing element for recording or reproducing magnetic signals by magnetic flat interlinkage with a magnetic transducer head during relative motion of the wire and head.

Abstract: A radio information system is described which uses the exact mathematical tios and the unique periodic angular coherence of the residual RF carrier and the digitally encoded modulation spectral components of the electromagnetic wave as emitted by a source transmitter (or transmitters) to enhance system performance and to provide new instrumentation and measurement capabilities at the receiver apparatus. The digital modulation synchronizing code occupies a wide frequency bandwidth and is encoded for precise repetitive transmission to provide, for example in a satellite navigation system, a means of accurate synchronization and measurement of time and range parameters. Many encoded sequences of either discrete or pseudo-random types may be used as the synchronizing code. However in the description herein the pseudo-random noise (PRN) codes are used for their added advantage in spread spectrum discrimination against intentional interference.

Abstract: A rapid laser scanning system utilizing an optical grating coupler (OGC) reby the angle at which an incident laser beam is outputted therefrom may be varied by the imposition of an electric field on a thin film underlying the coupler at right angles to the path of the laser beam through the thin film.

Abstract: A system for eliminating background signals in chopped infrared measuring systems employs operational amplifier principles for subtracting a reference signal of proper amplitude, phase and frequency from the background-plus-signal radiation. The output is converted to a dc voltage level directly related to incident flux.

Abstract: A three component liquid monopropellant composition, adaptable for provid underwater propulsion which comprises an amine salt, oxidant and a desensitizing quantity of water sufficient to provide cooling and steam generation. A method for providing underwater propulsion wherein the aforesaid liquid monopropellant is combusted in the combustion chamber of an underwater reaction motor.

Abstract: An improved plastic-bonded explosive formulation comprising a mixture of , RDX, or DATB and a resin having a silicone backbone which shrinks less and has better thermal stability than those presently known. The formulation was developed for use in advanced missile systems.

Abstract: A combustion system using a dilute hydrogen peroxide(H.sub.2 O.sub.2) solon as an oxidizer. The system uses the concept of Liquid Phase Extraction and eliminates part of the water produced during the decomposition of hydrogen peroxide into water (H.sub.2 O) and oxygen (O.sub.2). The elimination of a part of the water produced during the decomposition allows the energy resulting from the combustion of oxygen and a fuel to be used to increase the prime mover performance of the system. The system comprises a decomposition chamber, a liquid/gas separator, a heat exchanger and a combustion chamber. Dilute hydrogen peroxide solution is catalytically decomposed in the decomposition chamber. The oxygen and the water produced during the decomposition of H.sub.2 O.sub.2 are separated by means of the separator. Some portion of the separated water is extracted.

Abstract: A protective coupling circuit is located between the D.C. supply voltage the amplifier components of a push-pull switching amplifier to suppress transients created during switching. The coupling circuit comprises a power supply filter with an inductor coil and capacitor, and circuitry for limiting the voltage on the individual switching elements and the output coil. Excess voltages caused by transients are fed to the power supply filter. In an alternative embodiment the power supply filter inductor coil is actually an auxiliary winding on the amplifier output transformer rather than a separate coil. This allows for use of some smaller capacity circuit elements.

Abstract: An RF test signal generator including a driving oscillator, a pulse generr for generating narrow spikes at the oscillator frequency (such as a step recovery diode), a modulator and an attenuator. Since the very narrow pulse exhibits nearly constant amplitude in the frequency domain, a constant amplitude comb spectrum with frequency spacing at the oscillator frequency is generated so as to facilitate automated testing techniques.

Abstract: A thin omnidirectional antenna suitable for mounting and operation flush to ground plane. A flat metal probe is sandwiched between a pair of dielectric vanes which are enclosed in turn by a pair of metallic T-guides within a radiating cavity. The design achieves resonance for efficient radiation within an electrically small cavity.

Abstract: An impulsive safety-arming device provides handling safety in a rocket mo. Prior to arming, a piston is blocked in position to contain a squib, thereby preventing inadvertent ignition. After arming, the piston block is removed allowing high temperature, high pressure gas from the squib to force the piston past vent ports and to escape and ignite the motor.

Abstract: 1. An apparatus for producing low frequency compressional waves under water hich comprises two circular plates spaced in opposed parallel relation, a plurality of reciprocating fluid motors arranged in parallel between said plates, an independent fluid pump hydraulically connected to each of said motors for driving the same, a by-pass valve for each motor adjustable to vary the length of the stroke of such motor, a prime mover coupled to drive all of the pumps in synchronism, whereby the motors connected thereto reciprocate in unison to move said plates toward and away from each other at a frequency corresponding to the speed of the prime mover, and means for adjusting all of the by-pass valves in assembly, whereby the amplitude of oscillation of said plates is correspondingly varied.

Abstract: A solid state klystron comprising a switching regulator, power source, tuning adapter, and solid state oscillator utilizing supply voltages identical to those of a standard tube-type klystron.

Abstract: A system for determining the proper instant of time to launch an object, h as a target or torpedo, from an aircraft to cause the object to impact a water surface at a predetermined nose-down angle, thereby preventing structural damage due to high impact forces. The system utilizes signals produced by instrumentation representative of the aircraft pitch and angular rate of pitch. The desired launch altitude and predetermined impact angle are physically set into the system by means of adjustable voltage sources. These parameters are processed in the system such that the system forms a complete electronic analogy to the physical laws which govern the motion of the free falling object. In operation, the system continuously computes the predicted impact angle based on the instantaneous inputs of the aircraft's altitude, pitch angle and pitch rate. It then compares the predicted impact angle with the predetermined impact angle.

Abstract: A testing system and method for testing and evaluating the performance and ervice life of finger seals and skirts used on surface effects ships (SES). The system simulates actual conditions that SES seals would encounter and tests full scale portions of seals and skirts. The system and method comprises placing a number of seals together in a mounting frame that moves the finger relative to another surface to simulate the chaffing and wear that occurs during actual pitch and roll. Below and in contact with the finger seals/skirts is a surface which has a wave-shaped rigid contoured surface movable as a unit vertically and horizontally. On the surface is a water-retaining pile-like material that retains water flowed thereon.

Abstract: Fluoro-anhydride curing agents for fluorinated epoxy resins, especially for highly fluorinated epoxy resins selected from the class consisting of hydroxyperfluoroalkyl phthalic anhydride, hydroxyperfluoroalkyl pyromellitic dianhydride, and mixtures thereof; a fluoro-anhydride curing agent for fluorinated epoxy resins that is the toluene-soluble mixture prepared by heating a hydroxyperfluoroalkyl benzenepentacarboxylic acid at about 240.degree. C; precursors for all of the curing agents; and the epoxy resins prepared therefrom.

Abstract: A cable brake and lock device to control the release of a mooring cable crises a spring-biased piston abutting an elastic brake element, with the cable passing through both. An initial, preselected force is applied by the spring to the piston and the brake element, causing the element to lock onto the cable. When the force of the ambient, hydrostatic pressure exceeds that of the spring, the spring is compressed, releasing the piston from the elastic brake element to permit the cable to run freely. Any decrease in the ambient pressure will permit the piston to again contact the brake element to lock the cable.