Abstract: A system is provided for facilitating the use of an in-motion slit radiographic technique to inspect 3-dimensional composite materials. The system includes a lead lined device that is adjustable to form various slit shaped and size openings. When used in conjunction with a standard X-ray source and film, the device prevents the non-parallel and undesirable portion of the X-ray radiation from creating a distorted image when complex 3-dimensional structures are inspected.

Abstract: A receiver of pulsed phase modulated signals is disclosed. These signals are produced by switching a reactance on and off a power line. The receiver produces a sinusoidal current in phase with the current on the power line and a sinusoidal voltage nominally 90 degrees out of phase with the voltage on the power line. These sinusoids are multiplied together to produce a sinusoid of double the original frequency (which may be filtered out) and voltage levels (positive when the reactance is on line and negative when it is off). The absolute value difference between these voltage levels (if any) is used as an error voltage for feedback. The voltage sinusoid is modified by this feedback.

Abstract: The crosspolarization components radiated by adjacent orthogonally linearly polarized feed horns of a reflector antenna system are compensated by structural modifications incorporated in the feed horns. In a first embodiment, the modified feed horns have curved walls and included shaped septa. Other embodiments involve the use of shaped walls or shaped septa only. In the case of an offset reflector, asymmetric modifications of the wall shape and septa are employed. For flared feed horns with rectangular cross section, the crosspolarization compensation is provided by curving the forward edges of the horn walls convexly or concavely as required.

Abstract: Multifilament fibers of alumina are fabricated into a multi-directional preform which is densified through repeated infiltration with an aqueous solution of colloridal alumina, dried and fired.

Abstract: Epoxide compounds can be cured without resorting to the usual elevated temperatures by reducing the ambient pressure to 4.79 Pa or lower. This is particularly useful in potting circuitry.

Abstract: A novel composite explosive comprised of conventional explosive material and a mixture of boron and at least one other metal is disclosed. The other metal must be capable of exothermically reacting with boron to produce intermetallic compound and an energy release of at least about 1.0 kcal/gm. In a preferred embodiment of the composite explosive, pellets of a stoichiometric mixture of boron and titanium are mixed with cyclotetramethylenetetranitramine (HMX). By mixing the boron and at least one other metal which forms an intermetallic compound with boron in an exothermic reaction wherein the heat energy release is at least about 1.0 kcal/gm and adding a conventional explosive material to the mixture, there is an improved method of forming a mass of hot or molten particles in an environment when the conventional explosive is detonated.

Abstract: An improved material particularly suited for the thermal insulation of building structures such as residential housing. The material comprises an inorganic, low-density cellular thermally insulating foam comprising a gypsum matrix having minute cavities homogeneously distributed therein. The material has a dry density of less than about 6 pounds per cubic foot and a thermal coefficient of less than about 0.37. The gypsum matrix includes therein approximately 1 to 15% by weight of cement, approximately 0.5 to 7% by weight of mineral wool and at least approximately 0.25% by weight of chopped glass.

Abstract: Multiple electrical connections between circuits in axially displaced housings are made by mounting the connectors so that they are at right angles to the axis of the housings.

Abstract: Pressure measurements of drilling mud inside the drill string and outside by transducers mounted in an instrumentation sub near the drill bit provide rapid notice of the instrusion of fluids or solids into the borehole and also permit appropriate adjusting of the mud pumping pressure.

Abstract: Fiber reinforced ceramics are produced without pressing or sintering by treating the fibrous reinforcement with an aqueous slurry comprising an alkali silicate and a ceramic powder and thereafter drying.

Abstract: A method of coding to provide command signals simultaneously to selected devices is disclosed. Each device is assigned a different power of the same integer. Commands are then signaled to the desired devices by sending a series of pulses, the total of which is the sum of the integer raised to the power of each the devices to be commanded. Thus if devices having powers of 0 and 3 are to be commanded, and the integer is 2, 9 pulses would be sent. (2.degree.=1, 2.sup.3 =8, 1+8=9). Each different total will signal a unique device or a unique combination of devices.

Abstract: In lieu of passing all air to be conditioned over an evaporator coil which is cold enough to cause a substantial amount of water vapor to condense; only a portion of the air is cooled to this extent. The remaining air is cooled to a higher temperature (at which negligible water vapor condenses). The total work to recompress the vaporized refrigerant is thereby reduced.

Abstract: There is disclosed the manner in which a reflector for a solar energy collector is designed. The absorber is a right circular cylinder and is contained in an evacuated glass shroud. The glass shroud prevents the use of the reflector design technique of the prior art, and instead calculations are performed as if an absorber having a smaller diameter were to be used.

Abstract: Improved wicks for recirculating condensed vapor back to the discharge zone of a metal vapor laser are disclosed. The wicks are generally tabular in configuration and may be formed of sintered metal or of a metal substrate with a porous plasma sprayed layer thereon. Compatible wick metals are taught for use with different active vaporized metals.

Abstract: An electric signal representative of the rate of insolation is integrated to determine if it is adequate for operation of a solar energy collection system.

Abstract: Apparatus for processing data whereby a digital control signal is generated for effecting the presentation of a selected portion of a map image on a raster display. The data includes stored data words describing characteristics of line segments utilizable to construct the image. The line segments include line vectors representative of elongated features of the image and boundary vectors identifying boundaries between image areas of different brightness. Processing of the data is accomplished by means of two control loops. The first control loop performs selected macrosteps including arithmetic manipulations, on the data words to effect generation of the digital control signal. The second control loop effects selection of the macrosteps to be performed by the first loop and routes the data words within the generator in response to the instant data being processed by the generator.

Abstract: To simulate the radar return from terrain of particular generic type (e.g. desert, forest, cultivated land) it is a known suggestion to employ closed-loop shift register with feedback suitable to produce particular "texture" of return from specified terrain. It is here disclosed to synchronize output of such register with azimuthal position of simulated search radar; but this alone gives "grainy" effect because "smeary" or slowly changing amplitude with range in PPI sweep is not matched by corresponding lateral, or azimuthal, "smear". This objectionable effect is overcome by providing three sets of output terminals on feedback register, giving outputs corresponding to shifts for azimuths N, N+1, and N+2. By buffing together the three outputs, an azimuthal variation at a slow rate, comparable with the variation with range, is obtained, giving a more deceptive (and thus better) simulation.

Abstract: In communication system comprising plurality of earth stations tied together by relay (e.g. satellite-borne) in which status of individual subscriber line interface units must be continually reported to central control unit, only status changed since previous interrogation cycle is reported, with unchanged units being skipped over. When control is via satellite-borne relay, control unit sends interrogation commands to different stations at such time intervals that the report from one station arrives just as that from another station ends. For long transit times, this may result in all interrogation signals being transmitted before the first report in the sequence is received.

Abstract: An apparatus and a method are provided for detecting and measuring vibrations of a selected portion of a drill string in a bore hole. The vibrations are detected by a transducer which produces an electrical signal representative of the vibrations. The signal is applied to a band-pass filter which produces an output signal representative of vibrations occurring at frequencies within the pass band of the filter. The pass band is repetitively stepped through a predetermined frequency range under the control of digital circuitry.

Abstract: A single pair of conductors in a drill cable in a borehole is used not only to transmit power into the hole, but to transmit control commands into the hole, and to communicate sensor data back up to the surface. A frequency for power and communication of 1 kHz is employed; but this is frequency modulated by deviation of about 5 percent to transmit commands down-hole. A different non-interfering phase modulation is used to send data back to the surface by causing a susceptance (preferably capacitive) to be connected across the supply cable to signify a binary pulse. The alteration in phase between current into the cable and potential across it is observed at the surface and the pulses so detected are processed by conventional data processing techniques.