Abstract: The present invention is directed to a chemical etching composition for etching metals or metallic alloys. The composition includes a solution of hydrochloric acid, phosphoric acid, ethylene glycol and an oxidizing agent. The etching composition is particularly useful for etching metal surfaces in preparation for subsequent fluorescent penetrant inspection.

Abstract: A nickel-based superalloy is provided which is resistant to deterioration in hydrogen at high operating temperatures and pressures, and which thus can be used in hydrogen-fueled spacecraft such as the Space Shuttle. The superalloy is characterized by a two-phase microstructure and consists of a gamma-prime precipitated phase in a gamma matrix. The gamma matrix phase is a primary solid solution and the gamma precipitated phase will be an intermetallic compound of the type A.sub.3 B, such as nickel aluminide or titanide. Both phases are coherent, ordered, and compatible, and thus will retain most of their strength at elevated temperatures. The alloy consists essentially of (by weight):______________________________________ Ni 50-60% Cr 10-20% Al 2-6% Co 2-5% Ti 3-8% W 5-12% Mo 5-10% Nb 1-3% ______________________________________wherein the ratio W/MO is approximately equal to 1, and Ti/Al ranges from about 1 to about 2.

Abstract: A docking target is provided for use in automated docking of a first vehicle on which the target is located. The target comprising a pair of laterally extending arm portions lying in substantially the same plane and a central post extending outwardly from the plane of the arm portions. At least three reflectors are located on the target, two of the reflectors being located at the outboard ends of the arm portions and another reflector being located at the end of the central post. In an important embodiment, the reflectors comprise individual pieces of retroreflective tape. The reflectors, when viewed from the front of the target, are aligned along the longitudinal center line of the target, and can take a number of different shapes including circular or square.

Abstract: A prosthetic device for below-the-elbow amputees having a cuff, a stem, a housing, two hook-like fingers, an elastic band for holding the fingers together, and a brace. The fingers are pivotally mounted on a housing that is secured to the amputee's upper arm with the brace. The stem, which also contains a cam, is rotationally mounted within the housing and is secured to the cuff, which fits over the amputee's stump. By rotating the cammed stem between the fingers with the lower arm, the amputee can open and close the fingers.

Abstract: An electromagnetic projectile launcher provides acceleration of a superconducting projectile through the diamagnetic repulsion of the superconducting projectile. A superconducting layer is provided aft of the projectile, either directly on the projectile or on a platform upon which the projectile is carried, and a travelling magnetic field is caused to propagate along a magnetic field drive coil in which the projectile is disposed. The resulting diamagnetic repulsion between the superconducting projectile and the travelling magnetic field causes the projectile to be propelled along the coil. In one embodiment, a segmented drive coil is used to generate the travelling magnetic field.

Abstract: A variable magnification variable dispersion glancing incidence x-ray spectroscopic telescope capable of multiple high spatial revolution imaging at precise spectral lines of solar and stellar x-ray and extreme ultraviolet radiation sources includes a pirmary optical system which focuses the incoming radiation to a primary focus. Two or more rotatable carries each providing a different magnification are positioned behind the primary focus at an inclination to the optical axis, each carrier carrying a series of ellipsoidal diffraction grating mirrors each having a concave surface on which the gratings are ruled and coated with a mutlilayer coating to reflect by diffraction a different desired wavelength. The diffraction grating mirrors of both carriers are segments of ellipsoids having a common first focus coincident with the primary focus.

Abstract: A macromolecular crystal growing system especially designed for growing crystals in the low gravity of space as well as the gravity of earth includes at least one tray assembly, a carrier assembly which receives the tray, and a refrigeration-incubation module in which the carrier assembly is received. The tray assembly includes a plurality of sealed chambers with a plastic syringe and a plug means for the double tip of the syringe provided therein. Ganging mechanisms operate the syringes and plugs simultaneously in a precise and smooth operation. Preferably, the tray assemblies are mounted on ball bearing slides for smooth operation in inserting and removing the tray assemblies into the carrier assembly. The plugging mechanism also includes a loading control mechanism. A mechanism for leaving a syringe unplugged is also provided.

Abstract: A process for figuring the surface of a beryllium mirror to a predetermined urvature wherein the configuration of the mirror surface is sensed to locate areas of the mirror surfaces which are higher than desired and then a stream of phosphoric acid diluted with water and ethylene glycol is directed into contact with the areas of the mirror which are higher than desired while at the same time a current of 10 to 200 milliamps is passed through the stream to the mirror to electro-chemically polish the mirror surface.

Abstract: An antibacklash gear system wherein a pair of gears mounted for limited movement therebetween are biased by a spring to move the teeth of the gears out of register, the spring serving as a link between two levers mounted on one of the gears. The position of one of the levers may be adjusted to vary the force applied to the other lever by the spring to thereby vary the force urging the gears to move relative to each other.

Abstract: An acrylic fiber having dispersed therein 2 to 10 weight percent of a colloidal silica having an average particle size of about 1 to 4 microns, with a mean particle size of 2-3, preferably about 2, microns. This acrylic fiber has excellent whiteness and moisture transport characteristics and fabrics made from it have an improved crispness of hand.

Abstract: An acrylic fiber having improved basic dyeability and the method for making the same wherein an acrylic polymer containing a sulfonated vinyl monomer as a part thereof is dissolved in a suitable solvent to form a spinning dope and a solution of a second or additive polymer dissolved in the same solvent is added to the dope which is then spun to form fibers. The second polymer is selected from the group consisting of cellulose triacetate, polymethyl methacrylate, polyvinyl chloride, a polyamide of hexamethylenediamine with 1,1,3-trimethyl-5-carboxy-3-(p-carboxyphenyl) indane and a polyamide of hexamethylene diamine with isophthalic acid. The spin dope will contain 10 to 35 weight percent of polymer solids, with the amount of the second or additive polymer being 0.5 to 25 weight percent of the total polymer solids. Fibers spun from the dope have enhanced basic dyeability. The method is effective only when the acrylic polymer contains a sulfonated vinyl monomer as part of the acrylic polymer backbone.

Abstract: Disclosed is an acrylic fiber having improved basic dyeability. The fiber is made by a process wherein a copolymer of an acrylic monomer and a sulfonated vinyl monomer is dissolved in a solvent to form a spinning dope and a solution of polystyrene in the same solvent is added to the dope prior to spinning the dope to form fibers. The polystyrene will be in the form of a separate phase dispersed throughout the spinning dope and the fibers formed from the dope. Fibers formed from this polystyrene-containing dope have improved basic dyeability.

Abstract: The method for making bicomponent filaments from two spin dopes wherein the dopes are assembled into alternating layers in a feed tube leading to a transition tube connected to a conventional spinnerette, the layers then being fed through the transition tube and the spinnerette to form filaments. The feed tube has a constant cross-sectional area along the length thereof and the transition tube has a parabolic configuration such that the linear flow rate of the assembled dope layers passing through the transition tube decreases at a uniform rate as the cross-sectional area of the stream of assembled layers is increased to the cross-sectional area of the spinnerette, to thereby maintain the distinctness of the interfaces of the layers and thus insure that good bicomponent filaments will be formed.

Abstract: A fabric suitable for use in making sandbags and the method of making the same wherein the fabric is woven from a yarn of twisted staple acrylic fibers having a fiber length of about 7 to 20 cm and a denier per filament of about 5 to 15, preferably 10 to 15, the yarn having a total denier of about 200 to 2650. The yarn is wrapped with a continuous filament yarn of a type which is degraded by ultraviolet light, with the wrapping being done in such a manner that fuzziness of the yarn is reduced to the point where the yarn can be woven into fabric without the use of size and at a weaving efficiency of at least about 70%.

Abstract: An acrylic fiber having improved basic dyeability and hot/wet properties, the fiber being made up of a blend of (a) at least 60 weight percent of a polymer of at least 35 weight percent of acrylonitrile copolymerized with up to 65 weight percent of at least one other mono-olefinic monomer and a minor amount of a sulfonated vinyl monomer with (b) 0.5 to 40 weight percent of the polyterephthalamide of a mixture of 2,2,4 and 2,4,4 trimethyl hexamethylene diamine, the fiber being made up of a two-phase heterogeneous suspension of the polyterephthalamide in a continuous phase of the acrylic polymer. Without the sulfonated vinyl monomer the fiber will have superior hot/wet properties but will show no improvement in dyeability, the dyeability of the fiber being enhanced only when the sulfonated vinyl monomer is present as a part of the acrylic polymer chain.

Abstract: A reinforced acrylic fiber and the method for making the same wherein a diisocyanate selected from the group consisting of: ##STR1## is polycondensed to form a polycarbodiimide in the presence of a spinning dope made up of dimethylacetamide containing 10 to 30 weight percent of acrylic polymer dissolved therein. The polycarbodiimide is present in discrete particles in the spinning dope. The spinning dope containing the polycarbodiimide is extruded to form fibers which have good hot-wet properties.

Abstract: A system for lowering the level of turbulence in an opening over which a eam of air is flowing at a subsonic velocity wherein a fence positioned adjacent to the opening at an upstream location is provided with a plurality of apertures in the distal portion thereof. The apertures in the distal portion of the fence spread the shear layer of air flowing over the top edge of the fence and substantially reduce turbulence within the opening.

Abstract: A system for lowering the level of turbulence in an opening through a wall ver which air is flowing at a subsonic velocity wherein an arcuate flange is secured to the downstream edge of the opening and extends into the opening a distance of 0.11 to 0.22 times the length of opening in the direction air flow, the flange being tangent to the wall at the part of attachment of the branch.

Abstract: A rocket for firing from a tube having open ends wherein a rocket motor sed from a projectile is connected to the projectile by a frangible, ported collar, the front of the motor having a vent for allowing combustion products to flow into the tube between the motor and the projectile. The pressure of the combustion products between the motor and the projectile will break the collar to allow the projectile to exit from the tube at a high velocity.

Abstract: Apparatus for stabilizing the flight of a rocket wherein the body of the ket is provided with a plurality of petals arranged around the periphery of the aft end of the rocket with the leading end of each petal being pivotally attached to the rocket body such that the trailing end of each petal is free to move outward away from the rocket body. A ring slidably mounted on the rocket is linked to each of the petals in such a manner that as the ring moves in an aft direction on the rocket body the trailing ends of all of the petals simultaneously move outward equal distances from the rocket body.