Abstract: A method and apparatus for passing light bundles through a multiple pass sampling cell. The multiple pass sampling cell includes a sampling chamber having first and second ends positioned along a longitudinal axis of the sampling cell. The sampling cell further includes an entrance opening, located adjacent the first end of the sampling cell at a first azimuthal angular position. The entrance opening permits a light bundle to pass into the sampling cell. The sampling cell also includes an exit opening at a second azimuthal angular position. The light exit permits a light bundle to pass out of the sampling cell after the light bundle has followed a predetermined path.

Abstract: Sewn, quilted ceramic blankets (AFRSI) and integrally woven core insulation systems (TABI) were examined in a 170 decibel aeroacoustic environment under oscillating air loads. Preconditioning in a radiant heat source was done at both 2000.degree. F. and 2500.degree. F. before testing. A multi-layer ceramic weave construction based on an angle interlock weave architecture is superior over all other TPS systems examined. These configurations do not require a surface coating to enhance survivability. Single-ply TABI fabric surfaces using an insulated integrally woven core structure survive up to 2000.degree. F. without the use of a ceramic coating to toughen the surface to the aeroacoustic noise level. AFRSI blankets of the art require a ceramic coating in order to demonstrate comparable performance after exposure to a 2000.degree. F. radiant heat temperature.

Abstract: A novel rehydration beverage containing sodium chloride, sodium citrate and aspartame useful for rapid restoration of hydration homeostasis. The beverage is particularly useful for restoration of normal body fluid volumes and their intracellular and extracellular distribution during a hypohydration state observed in astronauts and air passengers.

Abstract: A method is provided for determining surface shear magnitude and direction at every point on a surface. The surface is covered with a shear stress-sensitive liquid crystal coating and illuminated by white light from a normal direction. A video camera is positioned at an oblique angle above the surface to observe the color of the liquid crystal at that angle. The shear magnitude and direction are derived from the color information. A method of calibrating the device is also provided.

Abstract: Blade-vortex interaction noises, sometimes referred to as "blade slap", are avoided by increasing the absolute value of inflow to the rotor system of a rotorcraft. This is accomplished by creating a drag force which causes the angle of the tip-path plane of the rotor system to become more negative or more positive.

Abstract: Composite flexible multilayer insulation systems (MLI) were evaluated for thermal performance and compared with currently used fibrous silica (baseline) insulation system. The systems described are multilayer insulations consisting of alternating layers of metal foil and scrim ceramic cloth or vacuum metallized polymeric films quilted together using ceramic thread. A silicon carbide thread for use in the quilting and the method of making it are also described. These systems are useful to provide lightweight thermal insulation for a variety of uses, particularly on the surface of aerospace vehicles subject to very high temperatures during flight.

Abstract: A method for performing image compression that eliminates redundant and invisible image components. The image compression uses a Discrete Cosine Transform (DCT) and each DCT coefficient yielded by the transform is quantized by an entry in a quantization matrix which determines the perceived image quality and the bit rate of the image being compressed. The present invention adapts or customizes the quantization matrix to the image being compressed. The quantization matrix comprises visual masking by luminance and contrast techniques and by an error pooling technique all resulting in a minimum perceptual error for any given bit rate, or minimum bit rate for a given perceptual error.

Abstract: A space suit sizing device using a ball nut and screw drive mechanism to shorten and lengthen components of a space suit. The device includes a rotatable member having an outer race formed on an inner surface thereof, and a translatable member having an inner race formed on an outer surface thereof. A plurality of recirculating balls are located in a space defined by the inner and outer races. As the rotatable member is rotated by hand, the translatable member is caused to move in and out of the rotatable member. Since one component of the space suit is connected to the translatable member, the length of this component varies in accordance with the position of the translatable member.

Abstract: A system is provided for determining tracking error in a propeller or rotor driven aircraft by determining differences in the aerodynamic loading on the propeller or rotor blades of the aircraft. The system includes a microphone disposed relative to the blades during the rotation thereof so as to receive separate pressure pulses produced by each of the blades during the passage thereof by the microphone. A low pass filter filters the output signal produced by the microphone, the low pass filter having an upper cut-off frequency set below the frequency at which the blades pass by the microphone. A sensor produces an output signal after each complete revolution of the blades, and a recording display device displays the outputs of the low pass filter and sensor so as to enable evaluation of the relative magnitudes of the pressure pulses produced by passage of the blades by the microphone during each complete revolution of the blades.

Abstract: A light-weight, economical device to alleviate a plurality of difficulties encountered in walking by a victim suffering from a drop foot condition. A legband girdles the leg below the knee and above the calf providing an anchor point for the upper end of a ligament having its lower end attached to a toe of a shoe or a toe on the foot. The ligament is of such length that the foot is supported thereby and retained in a normal position during walking.

Abstract: A method and apparatus for cutting a transverse slot about a bore of smaller diameter than that of the slot are disclosed. The invention consists of introducing a cutting head facing transversely to the bore, through the bore opening its distance from the mill shaft being progressively extended by the addition of spacers between the head and the shaft until the desired slot depth is obtained. The spacers are held in position by a cable passing from the cutting head through the series of spacers and out along the mill shaft. The mill shaft carrying the cutting head is moved transversely into the object wherein the slot is being cut as the object is being rotated thereabout by the mill table to which it is affixed.

Abstract: An angular position transducer utilizing photocells and a light source is disclosed. The device uses a fully rotatable baffle which is connected via an actuator shaft to the body whose rotational displacement is to be measured. The baffle blocks the light path between the light source and the photocells so that a constant semicircular beam of light reaches the photocells.When the assembly is in the null position the illuminated area of each of the photocells is equal. As the actuator shaft rotates, the baffle also rotates which causes an increase in the area of illumination of one of the photocells together with an equal decrease in the area of illumination of the other photocell.The current produced by the photocells is fed through a resistor, a differential amplifier measures the voltage drop across the resistor which indicates the angular position of the actuator shaft and hence of the object.

Abstract: A telephone multiline signaling system using a common signal pair of lines for transmitting coded electrical signals for selectively connecting one or more of a plurality of telephone lines to a telephone line or channel located at an operator's console. The operator can rapidly and automatically produce coded electrical signals by manipulating mechanical thumb wheel switches so as to instruct a service center to connect any one or more of a plurality of telephone lines to the console so as to enable the operator to listen and/or talk over a plurality of lines simultaneously. The system includes an on-site console having a plurality of mechanically operated thumb wheel switches provided thereon on which the desired lines to be connected thereto can be dialed in. Electrical coded signals are fed to a plurality of banks of line AND gates representing units, tens and hundreds, a group of channel gates and a command gate.

Abstract: A transportable bridge is provided which may be erected across a wide, e.g. 150 foot, depression, and with access to only one bank of the depression. The bridge comprises a pair of abutments and a plurality of deck units. The abutments are laterally extensible, and erectible, from a collapsed state; they each comprise a base, a pair of backstays pivoted to one end of the base, and a pair of beam columns pivoted to the other end of the base, the backstays and beam columns being at small, acute angles to the plane of the base in the collapsed position, and being erected to form a triangle in the use position. Connecting means at the free ends of the backstays and beam columns are automatically engaged upon erection. A pair of reaction beams each has one end pivoted to a beam column, intermediate its ends, and extends over the base and past the one end of the base: anchoring means anchor the reaction beams to the ground.

Abstract: A map is segmented into columns and rows, and pairs of segments are lamind back to back in a particular manner: the segments of each column serially, and the columns serially. A marginal flap is provided at the top of each segment, wider than the segment and with a slot in it as well as the segment. A ring passes through the slots to hold the segments together, and to permit the viewing of two segments which are adjacent in the map.

Abstract: In this pioneering invention, electrical energy in alternating or direct current form at any selected power, voltage, current, or frequency, within wide limits, is converted and controlled to other forms of electrical energy at uniformly and continuously controlled output waveform and voltage or current by means of progressive variation of magnetic flux in associated magnetic paths. For electrical energy regeneration, this invention relies on electromagnetic induction in windings surrounding variable permeance magnetic paths of ferrimagnetic or ferromagnetic materials. The controlling means rely upon progressive saturation and/or domain rotation for selected portions of the magnetic paths to yield a uniformly controllable permeance within the magnetic paths. Feedback techniques are used to stabilize the output and provide the means for external control of power output in combination with a reference source.

Abstract: A soil compactor for laboratory use to systematically and controllably coct specimens of soil and earth-rock mixture materials. The raising of a drop hammer after each strike to a pre-selected height is accomplished automatically by the use of a pneumatic cylinder in conjunction with sensing valves. A counter and deactivation valve are also provided so that the system will automatically shut off after the hammer drops a pre-determined number of times. Uniform compaction of each specimen is ensured by automatically rotating the specimen a pre-selected number of degrees after each strike by the hammer. The compactor is also vertically and horizontally adjustable so that specimens of various heights and widths can be accommodated.