Abstract: A BÏ2212 article may be formed by mixing metallic precursor powders including bismuth, strontium, calcium and copper in an oxygen-free atmosphere, mechanically alloying the metallic precursor powders in an oxygen-free atmosphere, and heating the metallic precursor alloy according to a temperature profile. The profile may include a ramp-up stage during which the alloy is heated to a peak temperature in an oxygen-free atmosphere, a dwell stage during which the alloy is held at the peak temperature for a dwell time, and a ramp-down stage during which the alloy is cooled from the peak temperature. During at least a portion of the dwell stage, the oxygen-free atmosphere is switched to an oxygen-inclusive atmosphere, wherein the alloy is oxidized to form a superconducting oxide, which may be sintered during or after oxidation. The alloy may be formed into a shape, such as a wire, prior to oxidizing.

Abstract: A BÏ2212 article may be formed by mixing metallic precursor powders including bismuth, strontium, calcium and copper in an oxygen-free atmosphere, mechanically alloying the metallic precursor powders in an oxygen-free atmosphere, and heating the metallic precursor alloy according to a temperature profile. The profile may include a ramp-up stage during which the alloy is heated to a peak temperature in an oxygen-free atmosphere, a dwell stage during which the alloy is held at the peak temperature for a dwell time, and a ramp-down stage during which the alloy is cooled from the peak temperature. During at least a portion of the dwell stage, the oxygen-free atmosphere is switched to an oxygen-inclusive atmosphere, wherein the alloy is oxidized to form a superconducting oxide, which may be sintered during or after oxidation. The alloy may be formed into a shape, such as a wire, prior to oxidizing.

Abstract: A thermoelectric composite and a thermoelectric device and a method of making the thermoelectric composite. The thermoelectric composite is a semiconductor material formed from mechanically-alloyed powders of elemental constituents of the semiconductor material to produce nano-particles of the semiconductor material, and compacted to have at least a bifurcated grain structure. The bifurcated grain structure has at least two different grain sizes including small size grains in a range of 2-200 nm and large size grains in a range of 0.5 to 5 microns. The semiconductor material has a figure of merit ZT, defined as a ratio of the product of square of Seebeck coefficient, S2, and electrical conductivity ? divided by the thermal conductivity k, which varies from greater than 1 at 300 K to 2.5 at temperatures of 300 to 500K.

Abstract: A gas turbine engine fan blade includes a main body having a radially spaced apart root and tip, and axially spaced apart leading and trailing edges. A front shell is fixedly joined to a portion of the body leading edge to collectively define with the body an airfoil having first and second opposite sides extending between the root, tip, shell, and trailing edge for pressurizing air flowing thereover. The shell is hollow to offset toward the trailing edge a collective center of gravity of the airfoil to reduce steady stress at the airfoil leading edge.

Abstract: A method and apparatus provide cooling air from a compressor to hot components in a gas turbine engine. Compressed air discharged from an exit of the compressor is stratified into a main flow channeled to a combustor, and a separate bleed flow channeled to a heat exchanger. The bleed flow has an above average pressure whereas the main flow has a below average pressure. The bleed flow is cooled in the heat exchanger and channeled to hot components of the engine for cooling thereof.

Abstract: A containment system for wide chord turbofan fan blades, the system having a containment housing which forms a nesting area to accommodate broken blades and blade parts. Connected to the containment housing and constituting a part of the nesting area are structural rings which are positioned so that centrifugal forces will direct the larger blade fragments to impact upon the structural rings causing the large blade fragments to break into smaller fragments which are then easily housed in the nesting area, thus reducing the required area of the nesting area and minimizing the weight of the containment system.

Abstract: Alloys are described which contain nickel, aluminum, boron, iron and in some instances manganese, niobium and titanium.

Abstract: A metallic glass alloy that is either iron-based or nickel-based or based on a mixture of iron and nickel, containing lesser amounts of elements selected from the group boron, silicon carbon and phosphorous to which is added an amount of a ductility enhancing element selected from the group cerium, lanthanum, praseodymium and neodymium sufficient to increase ductility of the metallic glass upon annealing.

Abstract: A turbomachine such as a compressor having one or more rows of blades designed to operate at a supersonic inlet relative Mach number is provided with a manifold surrounding the blade tips for extracting air from the passages between adjacent blades by an amount generally inversely related to the inlet relative Mach number, thereby restructuring the shock pattern. Extraction rate is modulated by a valve operatively connected to the turbomachine fuel control system.