Abstract: An apparatus and method of rendering audio. A binaural signal is split on an amplitude weighting basis into a front binaural signal and a rear binaural signal, based on perceived position information of the audio. In this manner, the front-back differentiation of the binaural signal is improved.

Abstract: A slow release, particulate urea-formaldehyde polymer useful as a fertilizer for enhancing the extended delivery of nitrogen needed for plant development and growth and a granular fertilizer made with the particulate urea-formaldehyde polymer.

Abstract: A coated aggregate material for enhancing the extended delivery of nitrogen needed for plant development and growth, the coated aggregate material having a slow release (extended-release) nitrogen coating of a particulate UF polymer adhered to the aggregate material with an adhesive binder.

Abstract: A multi-element rotor blade includes a main element and an active slat movable relative to the main element. The slat rotates and translates relative to the main element from a base position. The base position provides a compromise between minimum coefficient of drag CD and maximum coefficient of lift CLmax. In the advancing blade, since the airspeed thereof is significantly greater than the retreating blade, the slat is positively rotated from the base position to minimizes drag at low angles of attack. In the retreating blade, since the airspeed thereof is significantly lower than the advancing blade, the slat is negatively rotated and translated to maximize the coefficient of lift CLmax.

Abstract: A method for producing a composite component having a variable thickness includes placing a caul member over a plurality of laid-up prepreg plies supported by a mold. The mold includes a cavity for receiving the lay-up that is defined by a bottom surface, a plurality of walls extending upwardly from the bottom surface, and an open upper face surrounded by a mold edge. A support flange extends inwardly toward the center of the cavity from each of the walls at a predetermined distance from the bottom surface. The caul is made from an anisotropic material so that the caul is basically rigid about lateral axis and flexible about a longitudinal axis. During an autoclave curing process, the caul applies pressure along the length of the lay-up to draw the caul into engagement with the support flange, which serves as a stop to prevent further movement of the caul.

Abstract: A coated aggregate material for enhancing the extended delivery of nitrogen needed for plant development and growth, the coated aggregate material having a slow release (extended-release) nitrogen coating of a particulate UF polymer adhered to the aggregate material with an adhesive binder.

Abstract: An elastomeric coupler assembly having a helical elastomeric bearing movably supports an active slat relative to a main element. An inner elastomeric coupler assembly and an outer elastomeric coupler assembly support the slat therebetween. Centrifugal force operates to drive the slat to a first position and an actuator rod operates in tension to pull upon the inner elastomeric coupler assembly to drive the slat in opposition to the centrifugal force to a second position. The helical elastomeric bearing is layered such that it defines a section of a circular helix. The circular helix provides a coupling, which converts a linear input parallel to a virtual hinge axis into a rotary output to pitch the slat. In operation, centrifugal force operates to slide the slat outboard toward the blade tip such that the attached slat moves elastomerically along the helical arc of the helical elastomeric bearing to rotate the slat nose down.

Abstract: A seed for enhancing the extended delivery of nitrogen needed for plant development and growth, the seed having a slow release nitrogen coating of a particulate UF polymer adhered to the seed with an adhesive binder.

Abstract: A method for treating a seedling by dipping the roots of the seedling into a composition containing a slow release, particulate urea-formaldehyde polymer, which is useful as a fertilizer for enhancing the extended delivery of nitrogen needed for plant development and growth and to the composition useful as the root dip, or as a soil drench.

Abstract: An elastomeric coupler assembly having a helical elastomeric bearing movably supports an active slat relative to a main element. An inner elastomeric coupler assembly and an outer elastomeric coupler assembly support the slat therebetween. Centrifugal force operates to drive the slat to a first position and an actuator rod operates in tension to pull upon the inner elastomeric coupler assembly to drive the slat in opposition to the centrifugal force to a second position. The helical elastomeric bearing is layered such that it defines a section of a circular helix. The circular helix provides a coupling, which converts a linear input parallel to a virtual hinge axis into a rotary output to pitch the slat. In operation, centrifugal force operates to slide the slat outboard toward the blade tip such that the attached slat moves elastomerically along the helical arc of the helical elastomeric bearing to rotate the slat nose down.

Abstract: A multi-element rotor blade includes a main element and an active slat movable relative to the main element. The slat rotates and translates relative to the main element from a base position. The base position provides a compromise between minimum coefficient of drag CD and maximum coefficient of lift CLmax. In the advancing blade, since the airspeed thereof is significantly greater than the retreating blade, the slat is positively rotated from the base position to minimizes drag at low angles of attack. In the retreating blade, since the airspeed thereof is significantly lower than the advancing blade, the slat is negatively rotated and translated to maximize the coefficient of lift CLmax.

Abstract: A method and apparatus for producing a composite component having a variable thickness includes placing a caul member over a plurality of laid-up prepreg plies supported by a mold and curing the lay-up in an autoclave. The mold includes a cavity for receiving the lay-up that is defined by a bottom surface, a plurality of walls extending upwardly from the bottom surface, and an open upper face surrounded by a mold edge. A support flange extends inwardly toward the center of the cavity from each of the walls at a predetermined distance upward from the bottom surface. The predetermined distance varies along the length of the mold and generally conforms to the outer profile of the composite component to be fabricated. The caul is positioned over the lay-up and defines a longitudinal axis extending along the length of the caul and a lateral axis extending along the width of the caul.

Abstract: A method and apparatus for controlling the thickness of press-cured composite articles during the manufacture thereof. The method includes a preparatory or prefabrication stage wherein prepreg plies are layed up and compacted to form a plurality of laminates that define a final laminate package that defines the uncured configuration of the composite article. The final laminate package may include supplemental ply-packs layed up at the mid-plane or neutral axis of the final laminate package for the purpose of controlling the overall thickness of the final laminate package. The prepreg plies layed up in the preparatory stage have been precut to conform to the final net shape of the composite article, but include a predetermined overbuild in the width dimension to facilitate control of thickness during cure of the final laminate package.

Abstract: A method and apparatus for controlling the thickness of press-cured composite articles during the manufacture thereof. The method includes a preparatory or prefabrication stage wherein prepreg plies are layed up and compacted to form a plurality of laminates that define a final laminate package that defines the uncured configuration of the composite article. The final laminate package may include supplemental ply-packs layed up at the mid-plane or neutral axis of the final laminate package for the purpose of controlling the overall thickness of the final laminate package. The prepreg plies layed up in the preparatory stage have been precut to conform to the final net shape of the composite article, but include a predetermined overbuild in the width dimension to facilitate control of thickness during cure of the final laminate package.

Abstract: A method of making a flexible composite tool particularly adapted for composite molding and the composite tool made by this method. The method includes dissolving a B-staged fluoroelastomer in a suitable solvent such as methyl ethyl ketone or toluene to form a fluoroelastomer solution. A fabric is then coated with the fluoroelastomer solution. The solvent is evaporated and the impregnated fabric is sandwiched between unreinforced sheets to form a reinforced tooling material. The reinforced tooling material is laid up with alternating layers of unreinforced fluoroelastomer and then cured to form a composite tool which is stable through multiple thermal cycles. In addition, an elastomer tool can be provided with detail cavities shaped to accept separately formed detail structures, with each cavity including extra reinforcement in order to locate the details to close tolerances without extensive hand positioning or use of adhesives. The tool is useful in molding composites and is reusable.

Abstract: The method of manufacturing a multi-legged (preferably five) flexbeam for a hingeless flexbeam helicopter rotor, which flexbeam is of one-piece construction and made solely of composite materials, and includes full length plies of unidirectional high strength fibers extending from a first leg and splitting in passing through the hub portion of the flexbeam, and then extending into two substantially diametrically opposite legs, and having cross and unidirectional plies interspersed between the full length plies to effect the desired taper and shape of the flexbeam hub and legs, and wherein the final ply lay-up is made on a rotatable lay-up tool of dodecahedron shape.

Abstract: A method of making a flexible composite tool particularly adapted for composite molding and the composite tool made by this method. The method includes dissolving a B-staged fluoroelastomer in a suitable solvent such as methyl ethyl ketone or toluene to form a fluoroelastomer solution. A fabric is then coated with the fluoroelastomer solution. The solvent is evaporated and the impregnated fabric is sandwiched between unreinforced sheets to form a reinforced tooling material. The reinforced tooling material is laid up with alternating layers of unreinforced fluoroelastomer and then cured to form a composite tool which is stable through multiple thermal cycles. In addition, an elastomer tool can be provided with detail cavities shaped to accept separately formed detail structures, with each cavity including extra reinforcement in order to locate the details to close tolerances without extensive hand positioning or use of adhesives. The tool is useful in molding composites and is reusable.