Abstract: Cryogenic refrigeration system employs a power driven screw compressor which delivers pressurized refrigerant gas through a closed system to expand in a screw expander to produce refrigeration. The screw expander is rotatively coupled to the compressor. The screw compressor-screw expander cryogenic system includes heat exchangers and operates on the closed Brayton cycle to produce refrigeration.

Abstract: A spacecraft specifically adapted for launch from the space shuttle by means of a cradle having locking and ejection mechanisms mounted therein. The cradle fastens into the payload bay of the space shuttle and returns therewith for reuse in subsequent launches. The spacecraft mounts at three points to the cradle, and the cradle mounts at three points to the shuttle such that a plane through the attachment points passes through the roll axis of the spacecraft at approximately the center of mass thereof. The cradle utilizes the truss structure of the spacecraft to produce the required stiffness by providing a structural tie between the two ends and the bottom of the cradle. At launch, the spacecraft is ejected with both linear and angular momentum, the spin providing gyroscopic stability. The locking mechanisms in the cradle can be remotely controlled to relock the spacecraft to the cradle in the event of an unsuccessful deployment attempt.

Abstract: A shielded cable comprises a flat electrical insulator having a plurality of parallel spaced-apart conductors. A pluraity of openings extend through the insulator to expose at least one conductor. The shield, which is formed from an electrically conductive coating, not only covers the exterior of the insulator but also enters the openings and is electrically connected to the conductor. Gaps are created in the electrically conductive coating so as to provide areas for interconnection by an insulation displacement connector which "mass-terminates" all of the conductors. The exposed one conductor, which is in contact through the openings with the electrically conductive coating, maintains the electrical continuity of the shield notwithstanding the gap formed therein.

Abstract: Transformer configurations especially useful in the microwave frequency range. A reliable physical center-tap is achieved by the interposition of a stub at the center of an elongated member which provides electrical contact with a reactive impedance. The circuit formed thereby allows the reflection of an r.f. short circuit to the center of the elongated portion without attendant fabrication thereon. A loop configuration for the remaining coupling means allows adjustability of electromagnetic coupling which is less sensitive to spacing of primary and secondary than the common parallel configuration.

Abstract: Cylindrical ingots of materials that expand on melting or freezing are purified or zone refined by a process which includes providing a tubular container having both a cylindrical cavity and a slot along its entire length. In zone refining, as is well-known, a heater of a predetermined elevated temperature traverses from one end of a normally solid charge to another at least once to thereby sweep impurities to one end of the charge. During the zone refining process, material which expands on phase change (e.g., solid to liquid) flows into the slot. As a consequence, fractures and other damage to the container and/or zone-refined material are minimized. The substantially round cross section is retained following removal of the excess material from the zone refined ingot after solidification.

Abstract: A method for fabricating a thin-panel illuminator for uniform, high contrast lighting of large area graphic displays such as maps, photographs, charts, and the like. Light is introduced through one edge of a transparent substrate having front and back plane parallel opposed surfaces and thereby directed into the interior of the substrate. The back surface is textured with a multiplicity of shallow depressions such as grooves or dimples which have shallow sloped sides such that light is selectively directed from the interior of the substrate through a limited angle out of the substrate towards a display surface adjacent and coextensive with the back surface of the substrate and away from a viewer observing the display surface through the substrate.The diffusing surface is fabricated by roughening the back surface of the substrate to form relatively deep depressions which are then partially filled with an optically transparent liquid to thereby form relatively shallow depressions.

Abstract: Substrate for nickel-hydrogen battery electrode is etched from nickel sheet metal to provide inner and outer rims 54, 56 for self centering, a tab 62 on which a lead can be welded and properly distributed openings through conductors for optimum ion flow and electric conduction.

Abstract: The specification describes a process for defining a predetermined region on and above a substrate by using a resist pattern having a controlled line profile. First, a composite electron-beam sensitive resist comprising a bottom layer of resist, a middle layer of a chosen conductive material, and a top layer of resist is formed on a selected substrate. The substrate with the composite resist is exposed to a beam of electrons to simultaneously define a predetermined pattern in the top and bottom layers of the resist. Next, a first chosen solvent is applied for a first predetermined period of time to develop the pattern in the top layer of resist, with the layer of conductive material protecting the bottom layer of resist from exposure of the first chosen solvent. Then, the portion of the conductive layer which is exposed after development of the top resist layer, is removed.

Abstract: A digital watch having a face mounted detachable pulse sensor unit coupled to infrared plethysmograph electronics within the watch. The pulse sensor unit is detachable from a receptacle on the watch face and mountable into a receptacle at a first end of a remote pulse sensing cable. The second end of the cable is connected into the watch receptacle for conveying the pulse sensing information to the infrared electronics. A cuff holds the pulse sensor unit in place against the wearer's finger for sampling his heartbeat. The wearer may thus monitor his pulse rate while both hands are free.

Abstract: An improved organic acid activated liquid solder flux is provided by combining a carboxylic acid derivative of a condensed nuclear hydrocarbon, such as 1-naphthylacetic acid, with a flux base, such as rosin, and a solvent, such as isopropyl alcohol. Application of this mixture to solder joints to be made results in faster solder reflow and easier removal of flux residue than with a flux of substantially the same composition not employing the carboxylic acid. Any residues remaining are non-corrosive.

Abstract: Ion chamber 20 receives electrons from cathode 28 and produces ions by electron bombardment in discharge plasma chamber 20. Ions are extracted through ion optics including screen 22 and accelerator electrode 24. Higher ion densities in the center of the discharge chamber are reduced by spoiler 42 which is operated at a potential between cathode and anode potential. This reduces double ionization and central peaking to provide a more uniform ion beam through the optics. By employing laterally positioned spoiler elements beam steering can be accomplished. The ion source is useful wherever a uniform beam profile is desirable as in ion implantation. Controlling the direction of beam density is useful in ion machining and in ion thrusters for space application.

Abstract: Substrates prepared from chemically inert organic fibers that are non-wettable are rendered wettable by mechanically attached coatings of hydrophilic inorganic particles. The resulting inorganic-organic composites are suitable for use as separators in alkaline storage cells.

Abstract: Improved diimide and polyimide oligomers containing phenylacetylene terminal groups have been produced which melt at low temperatures and are curable into useful laminating resins, molding compounds and matrix resins. These oligomers are analogous to diimides and polyimides made from conventional dianhydrides, such as benzophenonetetracarboxylic dianhydride or pyromellitic dianhydride.

Abstract: The specification describes a process for ion beam etching fine patterns in a substrate using a protected resist mask which prevents erosion of the mask. First, a resist pattern is formed on the surface of a substrate to expose pre-selected areas of the substrate. Next, a selected material is deposited on the resist mask at a predetermined controlled angle of incidence with respect to the surface of the mask to form a relatively thin protective layer on the resist mask, having edges and patterns replicated from the edges and patterns of the resist mask and a negligible amount of the selected material deposited on the exposed substrate. Then, a beam of ions at a chosen energy is directed through openings in the protected mask to the substrate to etch the pre-selected areas. During etching, the protective layer on the resist prevents erosion of the resist mask and provides improved pattern definition for the etched region.

Abstract: A coupler for wavelength multiplexing or demultiplexing of multimode optical signals in optical circuits. Light introduced through an input/output surface at one end of a planar optical waveguide formed within a glass substrate propagates to a convexly curved second end of the waveguide on which is contiguously mounted a flexible, reflective diffraction grating. The light is diffracted by the diffraction grating and focussed by the curved end back onto the first end of the waveguide.In a multiplexer (beam combiner) embodiment, a plurality of optical signal sources, each having a different wavelength component, is aligned along the first end of the waveguide so that light propagating from each of the sources travels through the waveguide to the reflective diffraction grating, is diffracted by the grating and then brought to a common focus at the first end. An optical fiber abutting the first end is positioned at the common focus to receive the combined beams.

Abstract: A large scale parallel architecture in which many parallel channels numbering 10.sup.2 or more operate simultaneously to create a natural and efficient organization for processing two-dimensional arrays of data. The architecture comprises a plurality of stack integrated circuit wafers having top and bottom surfaces, electric signal paths extending through each of the wafers between the surfaces, and micro-interconnects (smaller than 50 mil) on the surfaces of adjacent wafers interconnecting the respective eletric signal paths with a topographical one-to-one correspondence.

Abstract: Stacked plates each have a plurality of thin etched flow passages to be employed in a tank containing gas and liquid for separation to provide gas free liquid. The liquid surface tension in the flow passages that are exposed to the gas provides a force to prevent the gas from entering the liquid galleries until the tank is void of liquid. Such separation is useful in fuel tanks in near zero gravity environment as well as in other separation duties.

Abstract: An inorganic-organic composite and method for making same wherein chopped zirconium oxide fibers are bonded together with a polymer. This composite is chemically stable and wettable in aqueous alkaline solutions, exhibits physical, chemical and thermal characteristics ideally suitable for use as separators in alkaline storage batteries, especially nickel-hydrogen and nickel-cadmium batteries.

Abstract: Commercially available alkali halide crystals are passivated in a plasma environment and coated by a plasma polymerization process to form moisture resistant alkali halide cyrstals. Prolonged exposure to high humidity did not cause observable damage to the surface of the crystal.