Abstract: A Stirling cycle heat engine is disclosed in which displacer motion is controlled as a function of the working fluid pressure P.sub.1 and a substantially constant pressure P.sub.0. The heat engine includes an auxiliary chamber at the constant pressure P.sub.0. An end surface of a displacer piston is disposed in the auxiliary chamber. During the compression portion of the engine cycle when P.sub.1 rises above P.sub.0 the displacer forces the working fluid to pass from the cold chamber to the hot chamber of the engine. During the expansion portion of the engine cycle the heated working fluid in the hot chamber does work by pushing down on the engine's drive piston. As the working fluid pressure P.sub.1 drops below P.sub.0 the displacer forces most of the working fluid in the hot chamber to pass through the regenerator to the cold chamber.

Abstract: An accelerometer telemetry system incorporated in a finger ring is used for monitoring the motor responses of a subject. The system includes an accelerometer, battery and transmitter and provides information to a remote receiver regarding hand movements of a subject wearing the ring, without the constraints of wires. Possible applications include the detection of fatigue from the hand movements of the wearer.

Abstract: Improvements in instrumentation suitable for measuring aircraft noise and sonic booms. A converter produces an electric current proportional to the sound pressure level at a condenser microphone. The electric current is transmitted over a cable and amplified by a zero drive amplifier. The converter consists of a local oscillator, a dual-gate field-effect transistor (FET) mixer and a voltage regulator/impedance translator. The local oscillator generates a carrier voltage that is applied to one of the gates of the FET mixer. The FET mixer mixes the microphone signal with the carrier to produce an electrical current at the frequency of vibration of the microphone diaphragm. The voltage regulator/impedance translator regulates the voltage of the local oscillator and mixer stages, eliminates the carrier at the output and provides a low output impedance at the cable terminals.

Abstract: A system for measuring momentum flux in a turbulently flowing fluid including a sensing apparatus for dynamically sensing the mainstream and the cross velocity components of the fluid, a transducer operative to provide two electrical output signals representative of the velocity components in the mainstream and in the cross direction, and signal processors to derive the Reynolds stress wave and the Reynolds stress.

Abstract: A method of forming a tubular wick for a heat pipe. The method is characterized by the steps of forming a wick blank of a predetermined thickness comprising a plurality of superimposed layers of stainless steel mesh screen, wet rolling the blank for reducing the thickness thereof, wrapping the blank about an inner mandrel, compressing the blank into a rigid tubular structure, removing the tubular structure from the mandrel and sintering the tubular structure.

Abstract: An apparatus is disclosed for imaging soft x-ray and ultraviolet electromagnetic radiation and charged particles. The apparatus includes a pair of microchannel electron multiplier plates that are connected in a cascaded chevron configuration which intercepts an incident beam of radiation or charged particles which are being imaged. Incident photons or charged particles strike the front surface of the chevron configuration causing emission of electrons. The electrons are accelerated by a voltage gradient and strike the inner side walls of the individual channels which comprise the microchannel electron multiplier plates causing emission of secondary electrons. Accelerated and multiplied secondary electrons impinge upon a resistive anode after they transverse the chevron configuration.

Abstract: A Self-Contained Breathing Apparatus with automatic redundant fluid pressure controls and a facemask mounted low pressure warning device. The apparatus utilizes two stages of pressure regulation wherein the final stage is the demand regulator that delivers the breathing gas to the wearer. The first state includes a pair of pressure regulators connected in parallel with different outlet pressures, both of which reduce the pressure of the stored supply gas to pressures compatible with the second stage breathing demand regulator. A primary regulator in the first stage delivers a low output pressure to the second stage demand regulator. In the event of a "failure closed" condition of the primary regulator an automatic transfer valve switches on the backup regulator and communicates its slightly higher outlet pressure to the demand regulator.

Abstract: Utilizing round optical fibers as communication channels in optical communication networks presents the problem of obtaining a high efficiency coupling between the optical fiber and the laser. A laser is made an integral part of the optical fiber channel by either diffusing active material into the optical fiber or surrounding the optical fiber with the active material. Oscillation within the active medium to produce lasing action is established by grating the optical fiber so that distributed feedback occurs.

Abstract: Apparatus for sensing the temperature, velocity, and direction of the wind, including four temperature-dependent crystal oscillators spaced about an axis, a heater centered on the axis, and a screen through which the wind blows to pass over the crystals. In one method of operation, the frequency of the oscillators is taken when the heater is not energized, to obtain the temperature of the wind, and the frequencies of the oscillators are taken after the heater is energized to determine the direction and velocity of the wind. When the heater is energized, the wind causes the downwind crystals to achieve a higher temperature than the upwind crystals, and with the magnitude of the difference indicating the velocity of the wind.

Abstract: The invention comprises of a pair of readout ring electrodes which are used in conjunction with apparatus for measuring the electrical impedance between different points in the body of a living animal to determine the amount of blood flow therebetween. The readout electrodes have independently adjustable diameters to permit attachment around different parts of the body between which it is desired to measure electric impedance. The axial spacing between the electrodes is adjusted by a pair of rods which have a first pair of ends fixedly attached to one electrode and a second pair of ends slidably attached to the other electrode. Indicia are provided on the outer surface of the ring electrodes and on the surface of the rods to permit measurement of the circumference and spacing between the ring electrodes. The ring electrodes are electrically isolated from each other.

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: Low density, fibrous, rigid, silica insulations are rendered impervious to moisture by application of a ceramic glaze coating comprising a silica barrier layer, an emissivity layer comprising a high silica glass component and an emmissivity agent and an overglaze layer comprising a high silica glass component and a borosilicate glass component. The resulting three-layered ceramic glaze laminate adhered to the fibrous silica insulation provides a moisture-impervious insulating material which exhibits a high emmissivity and is resistant to delamination and spalling at repeated cycles of thermal shock.

Abstract: Low density, fibrous, rigid, silica insulations are rendered impervious to moisture by application of a ceramic glaze coating comprising a silica barrier layer and an emissivity glaze layer comprising a high silica glass component, an emissivity agent and a borosilicate glass component. The resulting ceramic glaze laminate adhered to the fibrous silica insulation provides a moisture-impervious insulating material which exhibits a high emissivity and is resistant to delamination and spalling at repeated cycles of thermal shock.

Abstract: Simultaneous phase lock and synchronization acquisition of an L format biphase input signal having a pseudorandom sequence are obtained with a delay lock loop including a feedback shift register for deriving a first non-return to zero (NRZ) output signal having the same pseudorandom sequence as the input signal. An output of the shift register is compared with the input signal to derive a phase indicating binary error signal that is fed to a digital filter for deriving a binary output signal to control the transition times of a clock signal derived from a voltage controlled clock source. The digital filter is activated and the shift register is advanced in response to the clock signal. The input signal is converted into a second NRZ signal that has the same information content as the input signal. The first and second NRZ signals are compared to derive a further signal indicative of an estimate of the correlation function between the input signal and the output signal of the shift register.

Abstract: The invention is a device for counting aerosols and sorting them according to either size, mass or energy. The component parts of the invention are an accelerator, a capacitor sensor and a readout. The accelerator is a means for accelerating the aerosols toward the face of the capacitor sensor with such force that they partially penetrate the capacitor sensor, momentarily discharging it. The readout device is a means for counting the number of discharges of the capacitor sensor and measuring the amplitudes of these different discharges. The capacitor employed is a metal-oxide-silicon capacitor in which the metal and oxide layers are very thin. The aerosols are accelerated by the accelerator in the direction of the metal layer with such force that they penetrate the metal and damage the oxide layers, thereby allowing the electrical charge on the capacitor to discharge through the damaged region.

Abstract: A device for installing rocket engines supported at a cant relative to vertical, an axially extensible, tiltable pedestal, a lifting platform for supporting a rocket engine at its thrust chamber exit, including a mount having a concentric base characterized by a concave bearing surface, a plurality of uniformly spaced legs extended radially from the base, and an annular receiver coaxially aligned with the base and affixed to the distal ends of said legs for receiving the thrust chamber exit. The lifting platform rests on a seat concentrically related to the pedestal and affixed to an extended end portion thereof having a convex bearing surface mated in sliding engagement with the concave bearing surface of the annular base for accommodating a rocking motion of the platform about an axis angularly related to the longitudinal axis of the pedestal, whereby excessive asymmetric loading on the thrust chamber is avoided.

Abstract: A reusable silica surface insulation (RSI) material is provided by bonding amorphous silica fibers with colloidal silica at an elevated temperature. The surface insulation is ordinarily manufactured in the form of blocks (i.e., tiles).

Abstract: A system for sharing a memory in a fault-tolerant computer. The memory is under the direct control and monitoring of error detecting and error diagnostic units in the fault-tolerant computer. This computer, for example, verifies that data to and from the memory is legally encoded and verifies that words read from the memory at a desired address are, in fact, actually delivered from that desired address. The present invention provides the means for a second processor, which is independent of the direct control and monitoring of the error checking and diagnostic units of the fault-tolerant computer, to share the memory of the fault-tolerant computer and includes circuitry to verify that:1. The processor has properly accessed a desired memory location in the memory;2. A data word read out from the memory is properly coded; and3. No inactive memory was erroneously outputting data onto the shared memory bus.

Abstract: In a horn-reflector antenna system for producing a spherical aperture phase front, a corrugated conical horn illuminates a section of a hyperbolic reflector to produce a spherical aperture phase front which produces a far-field beam with low sidelobes and high beam efficiency. The system is insensitive to frequency and polarization changes, and is also insensitive to orientation about the axis of the conical horn for beam scanning.

Abstract: An apparatus is disclosed for holding a plurality of modular components against a surface. A fixture prepositions the components and a vacuum develops a uniform pressure which presses and holds the fixture and objects against a surface. The surface may be curved, vertical, or overhead and since local load concentrations are avoided, fragile ceramic tiles may be installed using the apparatus.