Abstract: This invention relates to the compositions and processes for preparing thermoset and thermoplastic polyimides derived from novel asymmetrical dianhydrides: specifically 2,3,3?,4? benzophenone dianhydride (a-BTDA), and 3,4?-(hexafluoroisopropylidene)diphthalic anhydride (a-6FDA). The a-BTDA anhydride is prepared by Suzuki coupling with catalysts from a mixed anhydride of 3,4-dimethylbenzoic acid or 2,3-dimethylbenzoic acid with 2,3-dimethylphenylboronic acid or 3,4-dimethylphenylboronic acid respectively, to form 2,3,3?,4?-tetramethylbenzophenone which is oxidized to form 2,3,3?,4?-benzophenonetetracarboxylic acid followed by cyclodehydration to obtain a-BTDA. The a-6FDA is prepared by nucleophilic triflouoromethylation of 2,3,3?,4?-tetramethylbenzophenone with trifluoromethyltrimethylsilane to form 3,4?-(trifluoromethylmethanol)-bis(o-xylene) which is converted to 3,4?-(hexafluoroisopropylidene-bis(o-xylene).

Abstract: Process for preparing polymer-reinforced silica aerogels which comprises a one-pot reaction of at least one alkoxy silane in the presence of effective amounts of a polymer precursor to obtain a silica reaction product, the reaction product is gelled and subsequently subjected to conditions that promotes polymerization of the precursor and then supercritically dried to obtain the polymer-reinforced monolithic silica aerogels.

Abstract: This invention is a highly concentrated stable solution of polyimide precursors (monomers) having a solids content ranging from about 80 to 98 percent by weight in lower aliphatic alcohols i.e. methyl and/or ethyl alcohol. The concentrated polyimide precursor solution comprises effective amounts of at least one aromatic diamine, at least one aromatic dianhydride or a lower molecular weight alkyl ester of said dianhydride, and a monofunctional endcap including monoamines, monoanhydrides and the lower alkyl esters of said monoanhydrides. These concentrated polyimide precursor solutions are particularly useful for the preparation of fibrous prepregs and composites for use in structural materials for military and civil applications.

Abstract: Ultra-high temperature, light-weight, black ceramic insulation having a density ranging from about 0.12 g/cc. to 0.6 g/cc. such as ceramic tile is obtained by pyrolyzing siloxane gels derived from the reaction of at least one organo dialkoxy silane and at least one tetralkoxy silane in an acid or base liquid medium. The reaction mixture of the tetra- and dialkoxy silanes also may contain an effective amount of a mono- or trialkoxy silane to obtain the siloxane gels. The siloxane gels are dried at ambient temperatures and pressures to form siloxane ceramic precursors without significant shrinkage. The siloxane ceramic precursors are subsequently pyrolyzed, in an inert atmosphere, to form the black ceramic insulation comprising atoms of silicon, carbon and oxygen. The ceramic insulation can be characterized as a porous, uniform ceramic tile resistant to oxidation at temperatures ranging as high as 1700° C.

Abstract: Non-flammable, fibrous-siloxane cured composites derived from the polymerization of dialkoxysilanes, trialkoxysilanes and tetraalkoxysilanes, in an aqueous medium, to obtain viscous polysiloxane resins. These siloxane resins are used to impregnate or coat various fibrous materials such as carbon fibers or glass cloth which are subsequently subjected to heat and pressure to form cured, non-flammable siloxane-impregnated composites e.g. panels having a density of about 1 to 3 g/cc. and a limited oxygen index above 30. These non-flammable, fibrous-siloxane composites are particularly useful in the manufacture of fire-proof materials for various transportation vehicles and for building materials e.g. panels as a fire barrier.

Abstract: A deforming charge assembly is provided which has an inner and an outer cylinder formed from carbon fiber. Each of the inner and outer cylinders have an inner circumference surface having an inner diameter and an outer circumference surface having an outer diameter. The inner diameter of the outer cylinder is greater than the outer diameter of the inner cylinder. Each of the inner and outer cylinders have a first layer of circumferentially wound carbon fiber, a second layer of unidirectional carbon fiber sheet and a plurality of layers of carbon fibers circumferentially wrapped around the second layer. A plurality of sympathetic detonation barrier members are provided and have an inner surface in contact with the outer circumference surface of the inner cylinder and an outer surface in contact with the inner circumference surface of the outer cylinder.

Abstract: Ultra-high temperature, light-weight, ceramic insulation such as ceramic tile is obtained by pyrolyzing a siloxane gel derived from the reaction of at least one organo dialkoxy silane and at least one tetralkoxy silane in an acid or base liquid medium. The reaction mixture of the tetra- and dialkoxy silanes may contain also an effective amount of a mono- or trialkoxy silane to obtain the siloxane gel. The siloxane gel is dried at ambient pressures to form a siloxane ceramic precursor without significant shrinkage. The siloxane ceramic precursor is subsequently pyrolyzed, in an inert atmosphere, to form the black ceramic insulation comprising atoms of silicon, carbon and oxygen. The ceramic insulation, can be characterized as a porous, uniform ceramic tile resistant to oxidation at temperatures ranging as high as 1700° C. and is particularly useful as lightweight tiles for spacecraft and other high-temperature insulation applications.

Abstract: This invention is a non-fragmenting warhead casing prepared from at least one thermosetting epoxy resin and carbon fibers wherein the epoxy resin is characterized as a liquid, low viscosity resin at ambient temperatures, curable at temperatures ranging up to 175° F. and further characterized has having a glass transition temperature T(g) ranging from about 200° F. to 250° F.

Abstract: A confinement cylinder is disclosed having opposite end regions and a cenl region, each acting as reservoirs for holding liquid metal for a metal vapor laser discharge device. The confinement cylinder is located at the central region of the discharge chamber of the laser device and allows the liquid metal to be raised to a temperature sufficient so that the liquid metal may transition into its vapor state, find its way back to the discharge chamber, and actively participate in the production of lasing.

Abstract: A three-dimensional grid is created by a series of panels arranged in a s-circle about a seated subject. The panels are configured or otherwise arranged to allow the seated subject full range of reach in all directions. The subject may be seated or standing and is placed a distance from the panels. The panels include a plurality of rods which slideably project through the panels in the direction of the seated subject. To determine reach, the subject reaches toward the rods and pushes them with either hand as far away from him/her as possible. Measurements may then be taken from the end of each rod that has been moved. Similarly situated panels, including visual indicia, may be used to evaluate field of view.

Abstract: A corrosion-resistant coating which can be applied directly to a surface as self-priming topcoat comprising an epoxy resin binder and a combination of pigments consisting essentially of an aluminum triphosphate, zinc salts of benzoic acids, and an alkaline earth metal phosphate such as zinc-barium phosphate. In addition, the coating contains up to about 30 parts by weight of a titanium dioxide pigment, up to about 2.0 parts by weight of an oil soluble surface active agent and up to about 50 parts by weight of at least one organic paint solvent.

Abstract: A system for monitoring the soldering process which comprises a soldering ans including a means for monitoring analog heat flow, a means, connected to said soldering means, for converting analog heat flow readings into a digital temperature data points, a computing means, connected to said means for converting analog heat flow readings into digital data points, which smoothes the temperature data points; locates the beginning of the temperature data point decay; locates the beginning of the temperature data point recovery; calibrates the system for monitoring the soldering process; and classifies the current temperature data point input as an iron cleaning operation or a soldering operation.

Abstract: A novel form of sandwich construction is disclosed. The lattice core sandh construction comprises of elongate lattice cells in side-by-side abutment, to present common, lengthwise flat sides that have facesheets co-cured thereto without any secondary bonding. Each lattice cell is formed by wrapping, in alterate patterns, fiber-reinforced, composite bands around commonly-shaped mandrels. Opppositely disposed face sheets are placed against flat sides and the construction co-cured. After co-curing, the mandrels are removed.

Abstract: A reconfigurable aircraft stick control for an aircraft simulator that enes pitch and roll to be simulated. It includes a generic base that has mounting means that are adapted to be connected to a stick control of the type having a standard production grip as well as a stick control that uses a yoke. The control sticks include linkages that are easily connected to the mounting means on the base so that control sticks can be exchanged with minimum expenditure of time and effort to thereby simulate the control sticks on aircraft that are being simulated. Torque motors can be connected to the simulator to detect the speed and displacement of the control stick and to provide resistance to movement of the control sticks so as to simulate actual flying conditions.

Abstract: An optical fiber strain sensor is provided which remembers the maximum stn a structure has experienced in a given timeframe. A pair of multi-mode optical fibers with flat ends meet end-to-end within a microbore capillary tube with which the fibers have frictional contact. The fibers are fastened to the structure at two points a known distance apart on either side of the capillary tube. Increasing strain in the structure pulls the fiber ends apart in proportion to the amount of strain; however, when strain is decreasing, the fibers buckle rather than move closer together. Therefore, the maximum strain is reflected as a maximum distance between the fiber ends. When the maximum strain experienced is to be measured, the free end of one fiber is connected to a light source and the free end of the other fiber is connected to a detector.

Abstract: An optical fiber strain sensor is provided which remembers the maximum stn a structure has experienced in a given timeframe. A reflective surface is fixed at one location on the structure, and a multi-mode optical fiber with a flat end is fixed at another location on the structure and is positioned so that its flat end is in contact with the reflective surface. A microbore capillary tube attached to the reflective surface encloses the fiber at its flat end and frictionally retains it in contact with the reflective surface. Increasing strain in the structure pulls the fiber end away from the reflective surface in proportion to the amount of strain; however, when strain is decreasing, the fiber buckles rather than moving closer to the reflective surface. Therefore, the maximum strain is reflected as a maximum distance between the fiber end and the reflective surface.

Abstract: A separator that separates a lubricating oil from a coolant both of which e used in a cutting or grinding machine is disclosed. The separator comprises input, intermediate and output chambers comprising divider panels having top and bottom portions. Every other panel has a passageway near its top region and the alternate panels, relative to the every other panels, have passageways located at their bottommost region. The lubricating oil finds its way into the path of the coolant and becomes mixed therewith. The mixed lubricating oil and coolant is eventually directed into the separator. As the oil and coolant flow sequentially through the chambers of the separator, the separating properties of the oil and the coolant begin to act so that the oil raises to the surface, whereas the coolant tends to seek its way through the chambers of the separator.

Abstract: An air-launchable gliding sonobuoy store includes a canister enclosing an flatable-membranous wing folded in a collapsed state with an electroacoustic system. After launching, the wing inflates and a steering mechanism controls the wing glide path by skewing the trailing edge thereof. Upon reaching the sea, the wing serves as a buoy with the electroacoustic system transducer depending therefrom.

Abstract: A corrosion-resistant polyurethane coating for application directly to a face as a self-priming topcoat comprising major amount of a polyurethane binder and minor amount of a combination of pigments consisting essentially of an aluminum phosphate, zinc salts of benzoic acids, and an alkaline earth metal phosphate such as zinc-barium phosphate. In addition, the coating contains up to about 30 parts by weight of a titanium dioxide pigment, up to about 2.0 parts by weight of an oil soluble surface active agent and up to about parts by weight of at least one organic solvent.

Abstract: A sandwich construction is disclosed that provides alternating offset and jacent corrugated strips secured between upper and lower face sheets. The peaks of one strip are adjacent the troughs of an adjacent strip. The peaks and troughs can have flattened portions and the face sheets can be secured to said portions.