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Oxidation-resistant interfacial coatings for fiber-reinforced ceramic composites (open access)

Oxidation-resistant interfacial coatings for fiber-reinforced ceramic composites

A ceramic-matrix composite having a multilayered interfacial coating adapted to protect the reinforcing fibers from long-term oxidation, while allowing these to bridge the wake of advancing cracks in the matrix, is provided by selectively mismatching materials within adjacent layers of the interfacial coating, the materials having different coefficients of thermal expansion so that a low toughness interface region is created to promote crack deflection either within an interior layer of the mismatched interfacial coating or between adjacent layers of the mismatched interfacial coating.
Date: April 22, 1999
Creator: Lara-Curzio, Edgar; More, Karren L. & Lee, Woo Y.
System: The UNT Digital Library
Fluidtight Seal for a Container (open access)

Fluidtight Seal for a Container

A fluidtight seal for a container is formed by abutting a metal ring with a step machined in a convexo-concave container closure device and inserting this assembly into an open end of the container. Under compressive force, the closure device deforms causing the metal ring to pivot about the step on the closure device and interact with symmetrically tapered inner walls of the container to form a fluidtight seal between the container and the closure device. The compressive force is then withdrawn without affecting the fluidtight characteristic of the seal. A destructive force against the container closure device is necessary to destroy the fluidtight seal.
Date: March 31, 1999
Creator: Morrison, Edward F.
System: The UNT Digital Library
Control Coil Arrangement for a Rotating Machine Rotor (open access)

Control Coil Arrangement for a Rotating Machine Rotor

A rotating machine (e.g., a turbine, motor or generator) is provided wherein a fixed solenoid or other coil configuration is disposed adjacent to one or both ends of the active portion of the machine rotor for producing an axially directed flux in the active portion so as to provide planar axial control at single or multiple locations for rotor balance, levitation, centering, torque and thrust action. Permanent magnets can be used to produce an axial bias magnetic field. The rotor can include magnetic disks disposed in opposed, facing relation to the coil configuration.
Date: May 5, 1999
Creator: Shah, Manoj R. & Lewandowski, Chad R.
System: The UNT Digital Library
Stator for Rotating Electrical Machine Having Multiple Controlwindings (open access)

Stator for Rotating Electrical Machine Having Multiple Controlwindings

A rotating electric machine is provided which includes multiple independent control windings for compensating for rotor imbalances and for levitating/centering the rotor. The multiple independent control windings are placed at different axial locations along the rotor to oppose forces created by imbalances at different axial locations along the rotor. The multiple control windings can also be used to levitate/center the rotor with a relatively small magnetic field per unit area since the rotor and/or the main power winding provides the biasfield.
Date: May 5, 1999
Creator: Shah, Manoj R. & Lewandowski, Chad R.
System: The UNT Digital Library
Portable Apparatus for the Measurement of Environmental Radon and Thoron (open access)

Portable Apparatus for the Measurement of Environmental Radon and Thoron

The radometer is a portable instrument for the measurement of the concentration of atmospheric radon/thoron in a test area. A constant velocity pump pulls the air from the outside at a constant flow rate. If the air is too moist, some or all of the sample is passed through a desiccant filter prior to encountering an electrostatic filter. The electrostatic filter prevents any charged particles from entering the sampling chamber. Once the sample has entered the chamber, the progeny of the decay of radon/thoron are collected on a detector and measured. The measured data is compiled by a computer and displayed.
Date: August 19, 1999
Creator: Negro, Vincent
System: The UNT Digital Library
Low Temperature Sorbents for removal of Sulfur Compounds from fluid feed Streams (open access)

Low Temperature Sorbents for removal of Sulfur Compounds from fluid feed Streams

A sorbent material is provided comprising a material reactive with sulfur, a binder unreactive with sulfur and an inert material, wherein the sorbent absorbs the sulfur at temperatures between 30 and 200 C. Sulfur absorption capacity as high as 22 weight percent has been observed with these materials.
Date: September 30, 1999
Creator: Siriwardane, Ranjan
System: The UNT Digital Library
Low Loss Composition of BA{sub X}SR{sub Y}CA{sub 1-X-Y}TIO{sub 3}:BA{sub 0.12-0.25}SR{sub 0.35-0.47}CA{sub 0.32-0.53}TIO{sub 3} (open access)

Low Loss Composition of BA{sub X}SR{sub Y}CA{sub 1-X-Y}TIO{sub 3}:BA{sub 0.12-0.25}SR{sub 0.35-0.47}CA{sub 0.32-0.53}TIO{sub 3}

A dielectric thin-film material for microwave applications, including use as a capacitor, the thin-film comprising a composition of barium strontium calcium and titanium of perovskite type (Ba{sub x}Sr{sub y}Ca{sub 1-x-y})TiO{sub 3}. Also provided is a method for making a dielectric thin film of that formula over a wide compositional range through a single deposition process.
Date: October 19, 1999
Creator: Xiang, Xiao-Dong; Chang, Hauyee & Takeuchi, Ichiro
System: The UNT Digital Library
In-situ method to remove iron and other metals from Solution in Groundwater down Gradient from Permeable Reactive Barrier (open access)

In-situ method to remove iron and other metals from Solution in Groundwater down Gradient from Permeable Reactive Barrier

This invention is directed to a process for treating the flow of anaerobic groundwater through an aquifer with a primary treatment media, preferably iron, and then passing the treated groundwater through a second porous media though which an oxygenated gas is passed in order to oxygenate the dissolved primary treatment material and convert it into an insoluble material thereby removing the dissolved primary treatment material from the groundwater.
Date: September 22, 1999
Creator: Carpenter, Clay E. & Morrison, Stanley J.
System: The UNT Digital Library
Automated Sample collection and Analysis unit (open access)

Automated Sample collection and Analysis unit

Autoramp is an atmospheric radionuclide collection and analysis unit designed for unattended operation. A large volume of air passes through one of 31 filter cartridges which is then moved from a sampling chamber and past a bar code reader, to a shielded enclosure. The collected dust-borne radionuclides are counted with a high resolution germanium gamma-ray detector. An analysis is made and the results are transmitted to a central station that can also remotely control the unit.
Date: March 31, 1999
Creator: Latner, Norman; Sanderson, Colin G. & Negro, Vincent C.
System: The UNT Digital Library
Planar fuel cell utilizing nail current collectors for increased active surface area (open access)

Planar fuel cell utilizing nail current collectors for increased active surface area

A plurality of nail current collector members are useful in the gas flow passages of an electrochemical device to optimize the active surfaces of the device and to provide structural support. In addition, the thicknesses of cathode and anode layers within the electrochemical device are varied according to current flow through the device to reduce resistance and increase operating efficiency.
Date: November 26, 1999
Creator: George, Thomas J. & Meacham, G.B. Kirby
System: The UNT Digital Library
Abrasion Resistant Coating and Method of making the same (open access)

Abrasion Resistant Coating and Method of making the same

An abrasion resistant coating is created by adding a ductile phase to a brittle matrix phase during spray coating where an Al-Cu-Fe quasicrystalline phase (brittle matrix) and an FeAl intermetallic (ductile phase) are combined. This composite coating produces a coating mostly of quasicrystal phase and an inter-splat layer of the FeAl phase to help reduce porosity and cracking within the coating. Coatings are prepared by plasma spraying unblended and blended quasicrystal and intermetallic powders. The blended powders contain 1, 5, 10 and 20 volume percent of the intermetallic powders. The unblended powders are either 100 volume percent quasicrystalline or 100 volume percent intermetallic; these unblended powders were studied for comparison to the others. Sufficient ductile phase should be added to the brittle matrix to transform abrasive wear mode from brittle fracture to plastic deformation, while at the same time the hardness of the composite should not be reduced below that of the original brittle phase material.
Date: June 25, 1999
Creator: Sordelet, Daniel J. & Besser, Matthew F.
System: The UNT Digital Library
Vacuum Enhanced Cutaneous Biopsy Instrument (open access)

Vacuum Enhanced Cutaneous Biopsy Instrument

A syringe-like disposable cutaneous biopsy instrument equipped with a tubular blade at its lower end, and designed so that a vacuum is created during use, said vacuum serving to retain undeformed a plug of tissue cut from a patient's skin.
Date: June 25, 1999
Creator: Collins, Joseph
System: The UNT Digital Library
Cryogenic Homogenization and Sampling of Heterogeneous Multi-Phase Feedstock (open access)

Cryogenic Homogenization and Sampling of Heterogeneous Multi-Phase Feedstock

An apparatus and process for producing a homogeneous analytical sample from a heterogeneous feedstock by: providing the mixed feedstock, reducing the temperature of the feedstock to a temperature below a critical temperature, reducing the size of the feedstock components, blending the reduced size feedstock to form a homogeneous mixture; and obtaining a representative sample of the homogeneous mixture. The size reduction and blending steps are performed at temperatures below the critical temperature in order to retain organic compounds in the form of solvents, oils, or liquids that may be adsorbed onto or absorbed into the solid components of the mixture, while also improving the efficiency of the size reduction. Preferably, the critical temperature is less than 77K (-196 C). Further, with the process of this invention the representative sample maybe maintained below the critical temperature until being analyzed.
Date: September 21, 1999
Creator: Doyle, Glenn M.; Ideker, Virgene D. & Siegwarth, James D.
System: The UNT Digital Library
Uniform bulk Material Processing using Multimode Microwave Radiation (open access)

Uniform bulk Material Processing using Multimode Microwave Radiation

An apparatus for generating uniform heating in material contained in a cylindrical vessel is described. TE{sub 10}-mode microwave radiation is coupled into a cylindrical microwave transition such that microwave radiation having TE{sub 11}-, TE{sub 01}- and TM{sub 01}-cylindrical modes is excited therein. By adjusting the intensities of these modes, substantially uniform heating of materials contained in a cylindrical drum which is coupled to the microwave transition through a rotatable choke can be achieved. The use of a poor microwave absorbing insulating cylindrical insert, such as aluminum oxide, for separating the material in the container from the container walls and for providing a volume through which air is circulated is expected to maintain the container walls at room temperature. The use of layer of highly microwave absorbing material, such as SiC, inside of the insulating insert and facing the material to be heated is calculated to improve the heating pattern of the present apparatus.
Date: June 18, 1999
Creator: Varma, Ravi & Vaughan, Worth E.
System: The UNT Digital Library
Process for Making a Ceramic Composition for Immobilization of Actinides (open access)

Process for Making a Ceramic Composition for Immobilization of Actinides

Disclosed is a process for making a ceramic composition for the immobilization of actinides, particularly uranium and plutonium. The ceramic is a titanate material comprising pyrochlore, brannerite and rutile. The process comprises oxidizing the actinides, milling the oxides to a powder, blending them with ceramic precursors, cold pressing the blend and sintering the pressed material.
Date: June 22, 1999
Creator: Ebbinghaus, Bartley B.; Van Konynenburg, Richard A.; Vance, Eric R.; Stewart, Martin W.; Walls, Philip A.; Brummond, William Allen et al.
System: The UNT Digital Library
A Monolithic Interconnected module with a tunnel Junction for Enhanced Electrical and Optical Performance (open access)

A Monolithic Interconnected module with a tunnel Junction for Enhanced Electrical and Optical Performance

An improved thermophotovoltaic (TPV) n/p/n device is provided. Monolithic Interconnected Modules (MIMs), semiconductor devices converting infrared radiation to electricity, have been developed with improved electrical and optical performance. The structure is an n-type emitter on a p-type base with an n-type lateral conduction layer. The incorporation of a tunnel junction and the reduction in the amount of p-type material used results in negligible parasitic absorption, decreased series resistance, increased voltage and increased active area. The novel use of a tunnel junction results in the potential for a TPV device with efficiency greater than 24%.
Date: June 30, 1999
Creator: Murray, Christopher Sean & Wilt, David Morgan
System: The UNT Digital Library
Method for Non-Intrusively Identifying a Contained Material Utilizing Uncollided Nuclear Transmission Measurements (open access)

Method for Non-Intrusively Identifying a Contained Material Utilizing Uncollided Nuclear Transmission Measurements

An improved nuclear diagnostic method identifies a contained target material by measuring on-axis, mono-energetic uncollided particle radiation transmitted through a target material for two penetrating radiation beam energies, and applying specially developed algorithms to estimate a ratio of macroscopic neutron cross-sections for the uncollided particle radiation at the two energies, where the penetrating radiation is a neutron beam, or a ratio of linear attenuation coefficients for the uncollided particle radiation at the two energies, where the penetrating radiation is a gamma-ray beam. Alternatively, the measurements are used to derive a minimization formula based on the macroscopic neutron cross-sections for the uncollided particle radiation at the two neutron beam energies, or the linear attenuation coefficients for the uncollided particle radiation at the two gamma-ray beam energies. A candidate target material database, including known macroscopic neutron cross-sections or linear attenuation coefficients for target materials at the selected neutron or gamma-ray beam energies, is used to approximate the estimated ratio or to solve the minimization formula, such that the identity of the contained target material is discovered.
Date: February 26, 1999
Creator: Morrison, John L.; Stephens, Alan G. & S., Grover Blaine
System: The UNT Digital Library
Method of Dehalogenation using Diamonds (open access)

Method of Dehalogenation using Diamonds

A method for preparing olefins and halogenated olefins is provided comprising contacting halogenated compounds with diamonds for a sufficient time and at a sufficient temperature to convert the halogenated compounds to olefins and halogenated olefins via elimination reactions.
Date: February 26, 1999
Creator: Farcasiu, Malvina; Kaufman, Phillip B.; Ladner, Edward P. & Anderson, Richard R.
System: The UNT Digital Library
Polymer Coating for Immobilizing Soluble Ions in a Phosphate Ceramic Product (open access)

Polymer Coating for Immobilizing Soluble Ions in a Phosphate Ceramic Product

A polymer coating is applied to the surface of a phosphate ceramic composite to effectively immobilize soluble salt anions encapsulated within the phosphate ceramic composite. The polymer coating is made from ceramic materials, including at least one inorganic metal compound, that wet and adhere to the surface structure of the phosphate ceramic composite, thereby isolating the soluble salt anions from the environment and ensuring long-term integrity of the phosphate ceramic composite.
Date: May 5, 1999
Creator: Singh, Dileep; Wagh, Arun S. & Patel, Kartikey D.
System: The UNT Digital Library
Aerogel Fingerprint Media (open access)

Aerogel Fingerprint Media

A fingerprint medium which is made of an aerogel having a predetermined density. The fingerprint medium may have a midrange density for forming plates or may be crushed forming a powder. The fingerprint medium may further include at least one of a metal and metal oxide to enhance characteristics desirable in a fingerprint medium.
Date: September 21, 1999
Creator: Miller, Fred S. & Andresen, Brian D.
System: The UNT Digital Library
Ceramic Composition for Immobilization of Actinides (open access)

Ceramic Composition for Immobilization of Actinides

Disclosed is a ceramic composition for the immobilization of actinides, particularly uranium and plutonium. The ceramic is a titanate material comprising pyrochlore, brannerite and rutile.
Date: June 22, 1999
Creator: Ebbinghaus, Bartley B.; Van Konynenburg, Richard A.; Vance, Eric R.; Stewart, Martin W.; Jostsons, Adam; Allender, Jeffrey S. et al.
System: The UNT Digital Library
Method for Producing Chemically Bonded Phosphate Ceramics and for Stabilizing Contaminants Encapsulated therein Utilizing Reducing Agents (open access)

Method for Producing Chemically Bonded Phosphate Ceramics and for Stabilizing Contaminants Encapsulated therein Utilizing Reducing Agents

Known phosphate ceramic formulations are improved and the ability to produce iron-based phosphate ceramic systems is enabled by the addition of an oxidizing or reducing step during the acid-base reactions that form the phosphate ceramic products. The additives allow control of the rate of the acid-base reactions and concomitant heat generation. In an alternate embodiment, waste containing metal anions is stabilized in phosphate ceramic products by the addition of a reducing agent to the phosphate ceramic mixture. The reduced metal ions are more stable and/or reactive with the phosphate ions, resulting in the formation of insoluble metal species within the phosphate ceramic matrix, such that the resulting chemically bonded phosphate ceramic product has greater leach resistance.
Date: May 5, 1999
Creator: Singh, Dileep; Wagh, Arun S. & Jeong, Seung-Young
System: The UNT Digital Library
Method of Forming Diamonds from Carbonaceous Material (open access)

Method of Forming Diamonds from Carbonaceous Material

A method for producing diamonds is provided comprising exposing carbonaceous material to ion irradiation at ambient temperature and pressure.
Date: November 30, 1999
Creator: Daulton, Tyrone; Lewis, Roy; Rehn, Lynn & Kirk, Marquis
System: The UNT Digital Library
A method to remove Ammonia using a Proton-Conducting Ceramic Membrane (open access)

A method to remove Ammonia using a Proton-Conducting Ceramic Membrane

An apparatus and method for decomposing NH{sub 3}. A fluid containing NH{sub 3} is passed in contact with a tubular membrane that is a homogeneous mixture of a ceramic and a first metal, with the ceramic being selected from one or more of a cerate having the formula of M' Ce{sub 1-x} M''O{sub 3-{delta}}, zirconates having the formula M'Zr{sub 1-x} M''3-{delta}, stannates having the formula M'Sn{sub 1-x}M''O{sub 3}-{delta}, where M' is a group IIA metal, M'' is a dopant metal of one or more of Ca, Y, Yb, In, Nd, Gd or mixtures thereof and {delta} is a variable depending on the concentration of dopant and is in the range of from 0.001 to 0.5, the first metal is a group VIII or group IB element selected from the group consisting of Pt, Ag, Pd, Fe, Co, Cr, Mn, V, Ni, Au, Cu, Rh, Ru and mixtures thereof. The tubular membrane has a catalytic metal on the side thereof in contact with the fluid containing NH{sub 3} which is effective to cause NH{sub 3} to decompose to N{sub 2} and H{sub 2}. When the H{sub 2} contacts the membrane, H{sup +} ions are formed which pass through the membrane driving …
Date: September 22, 1999
Creator: Balachandran, Uthamalingam & Bose, Arun C.
System: The UNT Digital Library