Abstract: A low NOx gas combustor includes an air injection mechanism to create a combustion air path. A set of arc-shaped gas injector arrays are formed in an annular configuration. Each arc-shaped gas injector array injects an arc-shaped stream of gas that intersects with the combustion air path to produce a fuel rich flame segment that is separated from an adjacent fuel rich flame segment from an adjacent arc-shaped gas injector array by an air rich zone. The interaction between the fuel rich flame segment and the air rich zone results in low NOx combustion of the gas.

Abstract: A method to reduce waterwall corrosion in a low NO.sub.x boiler includes the steps of locating a waterwall area of a low NO.sub.x boiler where oxidizing conditions exist and deposition of FeS is likely. The combustion air input at the waterwall area is biased to reduce FeS deposition on the waterwall. The biased combustion air input increases the oxidation rate of FeS.sub.2 so as to reduce FeS deposition on the waterwall. The biased combustion air input may be achieved by increasing the air-to-fuel ratio of one burner while reducing the air-to-fuel ratio of another burner, such that the overall air-to-fuel ratio in the low NO.sub.x boiler is substantially constant.

Abstract: A method of simultaneously reconstructing and testing a straddle-mount turbine blade hub with the turbine blades in place. The method employs a sector scan ultrasonic phased array mounted on one face of the hub to inspect the opposite face.

Abstract: An electrical cable protected against moisture by a tubular liquid crystal film having its molecules multiaxially oriented.

Abstract: The method for the reagentless removal of nitrogen oxides from oxygen rich exhaust streams which includes impinging the exhaust gases upon a catalyst which includes a Lewis base metal cation, bismuth oxide and a mixture of transition metal cations.

Abstract: A thermal barrier coating has several different layers, the first of which is an oxidation barrier. A phonon scattering zone is positioned on top of the oxidation barrier. The phonon scattering zone includes a plurality of phonon scattering interface layers, each of which is formed between a first ceramic material and a second ceramic material. The first and second ceramic materials are each between 1 and 1000 nanometers thick. An optical reflectance zone is positioned on the phonon scattering zone. The optical reflectance zone includes a second stack of ceramic materials with a plurality of optically reflecting interface layers, each of which is formed between a first ceramic material and a second ceramic material. The first and second ceramic materials are each between 0.1 and 1.0 microns thick.

Abstract: A method and apparatus are described for cleaning the inside of a heat exchanger tube while the tube is in operation and for simultaneously enhancing the heat transfer rate across the tube wall. The method consists of positioning a rod containing a tube cleaner inside of the heat exchanger tube and moving the rod in a back and forth motion during operation of the heat exchanger tube. The tube cleaner is designed to scrape the inside wall of the heat exchanger tube and to create turbulence in the fluid near the tube wall thereby improving the heat transfer rate across the tube wall.

Abstract: An apparatus for underwater welding has a housing and a diverter. The diverter is inside the housing and has an outer sheath and an inner sheath. A gap between the housing and diverter passes a screening fluid to form an outer screening jet that prevents water from flowing into a weld site near the electrode. The inner sheath forms a pair of channels in the inner diverter. One channel passes a shielding fluid that shields the weld site. The other channel forms an exhaust line for venting the weld site during welding.

Abstract: An apparatus for welding the interior surface of a tube includes a laser welding probe body configured for positioning within an interior surface of a tube. A centering mechanism relying upon fluid pressure is used to substantially center the laser welding probe body within an annular void defined between the laser welding probe body and the interior surface of the tube. In one embodiment, the centering mechanism is implemented with a set of seals. In another embodiment, the centering mechanism is implemented with a set of centering balls that respond to the fluid pressure and thereby operate to center the laser welding probe body within the annular void. The fluid pressure may be created with shielding gas used during the laser welding operation.

Abstract: A power plant water chemistry analysis apparatus and method relies upon water chemistry sensors to obtain power plant water chemistry data characterizing the chemical activity of a power plant water system. An analytical model processor is used to generate model predictions for the power plant water system. A statistical data fitting processor selects screened data from the power plant water chemistry data that corresponds to the model predictions. The screened data is processed by an artificial intelligence processor to derive power plant water chemistry diagnostic information. The artificial intelligence processor includes an expert system, rule base, plant water chemistry system simulator, and pattern recognition module.

Abstract: A method of producing austenite steel for use in the radiation zone of a nuclear reactor. The method comprising the steps of forming the austenite steel with about 17% by weight chromium, about 9 to 11.5% by weight nickel, about 0.04% by weight carbon, and iron impurities whose content of silicon is about 0.1% by weight and whose total content of sulfur and phosphorous is less than 0.03% by weight; and exposing the austenite steel to a temperature treatment at a temperature less than 1150 .degree. C. to produce a fine grain lattice with grain diameter features under approximately 20 .mu.m.

Abstract: An apparatus and method are described for removing vapor phase contaminants from a gas stream by placing a porous tube having a sorbent material into ductwork through which the gas stream passes. In a first mode of operation, vapor phase contaminants are adsorbed by the sorbent. In a second mode of operation, the porous tube is cleaned of any accumulated deposits, for example fly ash, while in place without having to stop the gas flow. In a third mode of operation, the sorbent can be regenerated in place and without having to stop the gas flow by heating and collecting the desorbed contaminants. This invention is particularly suited for the removal of vapor phase mercury from flue gas generated by a combustion process.

Abstract: A method is provided for controlling the proliferation of molluscs in target habitat by applying to the habitat a compound or mixture of compounds which are amines, ethoxylated amines, quaternary amines, ethoxylated quaternary amines and cyclic amines.

Abstract: A silicon solar cell has increased efficiency by providing an anti-reflection and passivation layer comprising a layer of silicon dioxide thermally grown on a surface of a silicon body and a layer of titanium dioxide deposited on the layer of silicon oxide. In fabricating the composite anti-reflection passivation layer, a layer of aluminum is first deposited on a surface of the thermally grown silicon oxide. After annealing the aluminum layer, the aluminum is removed from the silicon dioxide layer, and the layer of titanium dioxide is then deposited on the surface of the silicon dioxide from which the aluminum was removed. A layer of magnesium fluoride can be deposited on the surface of the titanium dioxide.

Abstract: Metal matrix composites are made by infiltrating packed loose fly ash with molten metal or metal alloy under low pressure. In some embodiments the infiltration is driven by pressurized gas. Coating the fly ash prior to infiltration can lower the threshold of pressure required for satisfactory infiltration by the molten metal. In some embodiments nickel coated cenosphere fly ash is employed. Resulting metal-fly ash composites have high volume fractions of fly ash, and the fly ash is uniformely distributed in the metal matrix. The densities of the composites are relatively low, particularly in composites made using cenosphere fly ash.

Abstract: A protective overload device (POD) that absorbs energy and reduces the damage to transmission towers resulting from sudden conductor, shield wire, insulator, or conductor suspension failures is herein disclosed. The POD is positioned between the non-energized end of the insulator and the tower or support structure, or between the energized end of the insulator and the conductor. The POD consists of a top lid, a bottom plate, and a ductile load fuse refill disk. The top lid is slotted at regular intervals to allow for transverse deformation of the individual fingers that hold the bottom plate. The ductile load fuse refill disk consists of a filler material in which a steel cable is embedded. The POD acts as a passive rigid link under normal conditions. In the event of a dynamic shock that could fail a tower or tower arm, the fingers of the top lid will move outward along the sliding plane of the bottom plate until the bottom plate separates from the top lid.

Abstract: Metal matrix composites comprising of a solid preform comprising of a filler phase containing fly ash and a binding material having a binder to water ratio of 1:1 to 1:9, wherein the preform contains a metal homogeneously distributed within the preform.

Abstract: A three-phase dc to-ac power inverter includes a dc power source with a first dc node for positive voltage, a second dc node for negative voltage, and a third dc node for zero voltage. A set of three-level pole circuits are connected to the first dc node, the second dc node, and the third dc node of the dc power source. A control circuit, responsive to an inverter voltage vector reference demand signal with a voltage magnitude reference demand component and a voltage phase reference demand component, generates pole control signals for the three-level pole circuits using logic circuitry which combines phase indexed digital waveform values stored in a pair of lookup tables. The pole control signals force the three-level pole circuits to generate a set of phase-shifted waveforms with zero voltage components. The phase-shifted waveforms are combined by a set of transformers to produce a three-phase output voltage with a harmonic content lower than the harmonic content of the phase-shifted waveforms.

Abstract: A resonant DC link converter which is specifically adapted for driving a switched reluctance motor (SRM) using low power (VA) rated switches, includes an input circuit providing a DC supply voltage, a resonating inductance (connected to the switched input circuit) for generating a resonating DC link current, and an output converter circuit synthesizing a multi-phase AC output signal to power a respective phase winding of the SRM. A controller switches the switch devices of the input circuit and output converter circuits in a predetermined sequence.

Abstract: Methods are provided to at least slow the dissolution of silica in an aqueous environment. In the subject methods, the silica surface is contacted with a multivalent metal cation capable of complexing with oxygen atoms present on the silica surface, where contacting is preferably accomplished by introducing a source of the multivalent metal cation into the aqueous environment. The subject methods find particular use in the inhibition of the dissolution of silica comprising neutron poisoning materials employed in the storage of spent nuclear fuel.