Abstract: Fiber-reinforced plastic composite materials are fire-protected by the apcation thereon of a combination of coatings comprising a ceramic coating and an intumescent coating. The ceramic coating consists of zirconia stabilized with yttria.

Abstract: Improved acoustic damping materials comprise interpenetrating polymer netks having a soft polymer component and a hard polymer component. The soft polymer component, constituting from 75 to 95, preferably 90, percent by weight of the material, is made by polymerizing an aromatic diisocyanate with a polyalkylene ether glycol, and the hard polymer component is a vinyl ester polymer made by polymerization of the acrylate or methacrylate ester of the diglycidyl ether of a polyphenol. The curing of the mixture is carried out at room temperature in presence of a peroxide and an aromatic amine. The mixture of ingredients, while liquid, may be injected into mechanical devices, such as shafts of rotating equipment whose noise is to be dampened, and allowed to cure therein.

Abstract: A hull extension is attached at an appropriate distance above the hull bottom surface to the stern of a planing water craft so as to be at least partially submerged at subplaning speeds and totally unsubmerged at planing speeds, effectively increasing hull length at subplaning speeds while not affecting hull length at planing speeds. A "step" effect is thus featured whereby the hull extension is not in contact with the water once planing commences. Hydrodynamic and buoyant efficiency is increased by the hull extension at subplaning speeds and unaffected thereby at planing speeds. The hull extension also offers practical utility in terms of providing additional protection, deck space and mounting area.

Abstract: Improved acoustic damping materials comprise interpenetrating polymer netks having a soft polymer component and a hard polymer component. The soft polymer component, constituting from 50 to 90, preferably 70, percent by weight of the material, is made by polymerizing an aromatic diisocyanate with a polyalkylene ether glycol, and the hard polymer component is a vinyl ester polymer made by polymerization of a vinyl ester resin such as the acrylate or methacrylate ester of the diglycidyl ether of a polyphenol. Optionally, the vinyl ester resin may be brominated, whereby increased fire retardance is conferred upon the interpenetrating polymer network. The mixture is cured at room temperature.

Abstract: A method of protecting acoustic and damping tiles from fire damage by placing a fire barrier silicone foam sheet on the inner surface of a mold, mounting the mold at a selected distance from the surface of a hull of a vessel with the fiberglass cloth side of the silicone foam sheet facing the hull and spaced therefrom, injecting a polyurethane foam into the space between the hull surface and the silicone foam sheet, curing the polyurethane foam, and removing the mold. The porosity of the polyurethane foam is imparted by incorporation of 5-50% by volume of Saran.RTM. microspheres.

Abstract: In accordance with the present invention, a device to suction off the portion of the boundary layer closest to the hull and expel it alongside the ship is provided. The invention comprises a casing mounted in substantially parallel spaced alignment to the ship hull for diverting the portion of the ship boundary layer in immediate proximity to the underwater hull, at least one pump in communication with the casing for drawing up water from the ship boundary layer that enters into the casing, and at least one outlet nozzle in communication with the pump for expelling the water alongside the hull. The invention removes the portion of the fluid with the highest concentration of vorticity thereby removing the mechanism by which the "inverse bubbles" and floating drops persist far downstream of the ship's stern and thus suppressing the source of the most detectable features of the ship's wake radar image.

Abstract: In accordance with the present invention, an improved variable breadth imler for use in a variable capacity centrifugal pump and a method for adapting a variable capacity centrifugal pump to produce a specific predetermined shutoff head are provided. The variable breadth impeller is a two piece unit comprising an impeller element having a plurality of radially extending impeller vanes thereon and an axially movable shroud having a plurality of radially extending grooves therein for receiving the impeller vanes in a meshing relationship. The movable shroud further includes a plurality of axially extending grooves in its outer peripheral surface which act as a supplemental pumping means between minimum flow rate condition and shutoff condition. The operation of the improved variable breadth impeller results in a specific predetermined pressure head being attained and maintained at pump shutoff operating condition.

Abstract: An improved ceramic-plus-metal superconducting composition of YBa.sub.2 Cu.sub.3 O.sub.6+x plus substantially pure aluminum for ultimate use in making superconducting devices such as wires and tapes for utilization in motors, generators, electric circuits, etc.

Abstract: This invention relates to polymeric materials formable by casting at room mperature and having antifouling material incorporated therein. It is the reaction product of a) with polyether polyols and methylene bis (4-cyclohexyl) isocyanate, where a) is a polymer composition which is the reaction product of the distilled tributyltin oxide with a copolymer of either methyl methacrylate or methyl acrylate and, with either methacrylic acid or acrylic acid in such proportion that four (4) percent of the carbonyl groups remain unreacted.

Abstract: The invention is directed to a device for pumping electro-rheological flu comprising a casing that defines an inner rotor chamber having a central inlet opening and a peripheral discharge opening. Rotatably disposed within said chamber is a rotor for imparting energy to the pumped electro-rheological fluid comprising of a plurality of non-conducting coaxial substantially parallel spaced disks. On one face of each disk are embedded one or more electrodes and on the opposing face of each disk are attached one or more conductive surfaces. By selectively applying an electric charge to the embedded electrodes, an electric field is produced between the electrodes and the conducting surfaces of adjacent disks. As a result, the viscosity of the electro-rheological fluid exposed to the applied electric field is increased thereby producing electro-rheological fluid vanes between adjacent disks.

Abstract: The invention is directed to an improved multihull vessel for enhanced seakeeping and reduced hydrodynamic fluid resistance and a method for minimizing the wavemaking resistance of multihull vessels. Lower wavemaking resistance is realized while maintaining the advantageous seakeeping characteristics of small waterplane area multihull vessels. By the proper arrangement of slender, tapered hull elements, the present invention produces favorable wave interference effects and smaller surface wave disturbances resulting in lower wavemaking resistance. A tapered hull design provides a small waterplane area for enhanced seakeeping while producing smaller surface wave disturbances and reduced hull interaction resistance due to the lack of surface discontinuities. In addition, proper arrangement of hull elements provides favorable wave interference.

Abstract: A method for making superconducting ceramic filaments by joining the ceramic to a normal conducting metal in such a way that minimal mechanical working, drawing, or extrusion is needed to arrive at a fine filamentary shape.

Abstract: An omni-directional hydrophone having a pair of fiber-optic windings wrapped around a resilient ball to form a spherical acoustic sensor is provided. The fiber-optic pair has a first fiber which has a bonded jacket and a second fiber which has an unbonded jacket. The fiber with the bonded jacket is sensitive to both vibration of the mounting structure and impinging acoustic signals. The fiber with the unbonded jacket is sensitive to vibration but insulated from the acoustic signals. By comparing the signals from the two fibers, the hydrophone detects acoustic signals by detecting the phase difference between the two fibers. As both fibers are equally affected by vibration, there is no phase difference caused by vibration. This mechanization permits the canceling of vibration induced signals while retaining full sensitivity to acoustic signals. The hydrophone uses a standard fiber-optic laser source and detection system to convert the acoustic generated phase change to amplitude dependent voltage signals.

Abstract: A corrosion resistant structure having an outer ceramic layer of alumina stabilized zirconia resistant to oxidation at high temperatures, over a base alloy selected from the group consisting of CoCrAlY and NiCrAlY and applied to the base alloy by physical vapor deposition process, such as reactive magnetron sputtering wherein the outer ceramic layer has a thickness of from about 0.5 .mu.m to about 200 .mu.m.

Abstract: A rotor and a method for the production thereof which incorporates the inently strong, highly damped, yet light weight characteristics of fiber reinforced plastic composites, Achieving with a minimal amount of added weight in the form of high density material a significant reduction in the vibratory response of the rotor due to hydrodynamic flow excitation, by selectively tailoring the mass distribution therein as by adding the high density material at selected locations of the rotor.

Abstract: A fiber-optic hydrophone having a pair of jacketed fiber optic windings fed in a concentric planar spiral configuration in a layer of polyurethane is provided. One of the fiber optic windings has a fiber with a bonded acoustically sensitive jacket thereby increasing its sensitivity to acoustic energy. The second fiber optic winding, the reference winding, has a unbonded jacket enclosing the fiber resulting in reduced sensitivity to acoustic energy. Sensitivity to vibrational energy; however, is not reduced. The combining of signals from the pair of fibers provides a vibration-canceled acoustic signal.

Abstract: This invention is directed to a high damping and damage tolerant flexible opeller assembly and a method for the production thereof. The high damping and damage tolerant flexible propeller has a unitary hub having an axis of rotation and adapted for mounting on a rotatable shaft, multiple spokes extending from the hub portion, each spoke at its tip portion being made of a high density material having the shape that conforms to that of the specific propeller, each spoke at its inner portion from the tip portion to the hub portion being made of multidimensional fibers, the inner portion of each spoke being made of a multidimensional fiber preform being impregnated with a highly viscoelastic matrix material.