Control system for a wound-rotor motor (open access)

Control system for a wound-rotor motor

A load switching circuit for switching two or more transformer taps under load carrying conditions includes first and second parallel connected bridge rectifier circuits which control the selective connection of a direct current load to taps of a transformer. The first bridge circuit is normally conducting so that the load is connected to a first tap through the first bridge circuit. To transfer the load to the second tap, a switch is operable to connect the second bridge circuit to a second tap, and when the second bridge circuit begins to conduct, the first bridge circuit ceases conduction because the potential at the second tap is higher than the potential at the first tap, and the load is thus connected to the second tap through the second bridge circuit. The load switching circuit is applicable in a motor speed controller for a wound-rotor motor for effecting tap switching as a function of motor speed while providing a stepless motor speed control characteristics.
Date: July 17, 1981
Creator: Ellis, James N.
System: The UNT Digital Library
Electrochemical cell and negative electrode therefor. [Li-Al anode] (open access)

Electrochemical cell and negative electrode therefor. [Li-Al anode]

A secondary electrochemical cell is described with the positive and negative electrodes separated by a molten salt electrolyte with the negative electrode comprising a particulate mixture of lithium-aluminum alloy and electrolyte and an additive selected from graphitized carbon, Raney iron or mixtures thereof. The lithium-aluminum alloy is present in the range of from about 45 to about 80% by volume of the negative electrode, and the electrolyte is present in an amount not less than about 10% by volume of the negative electrode. The additive of graphitized carbon is present in the range of from about 1 to about 10% by volume of the negative electrode, and the Raney iron additive is present in the range of from about 3 to about 10% by volume of the negative electrode.
Date: July 29, 1981
Creator: Kaun, T.D.
System: The UNT Digital Library
Fast transient digitizer (open access)

Fast transient digitizer

Method and apparatus are presented for sequentially scanning a plurality of target elements with an electron scanning beam modulated in accordance with variations in a high-frequency analog signal to provide discrete analog signal samples representative of successive portions of the analog signal; coupling the discrete analog signal samples from each of the target elements to a different one of a plurality of high speed storage devices; converting the discrete analog signal samples to equivalent digital signals; and storing the digital signals in a digital memory unit for subsequent measurement or display.
Date: July 8, 1981
Creator: Villa, F.
System: The UNT Digital Library
Frequency spectrum analyzer with phase-lock (open access)

Frequency spectrum analyzer with phase-lock

A frequency-spectrum analyzer with phase-lock for analyzing the frequency and amplitude of an input signal is comprised of a voltage controlled oscillator (VCO) which is driven by a ramp generator, and a phase error detector circuit. The phase error detector circuit measures the difference in phase between the VCO and the input signal, and drives the VCO locking it in phase momentarily with the input signal. The input signal and the output of the VCO are fed into a correlator which transfers the input signal to a frequency domain, while providing an accurate absolute amplitude measurement of each frequency component of the input signal.
Date: July 29, 1981
Creator: Boland, Thomas J.
System: The UNT Digital Library
Gas-Driven Microturbine (open access)

Gas-Driven Microturbine

The present invention is directed to a means of fabricating a gas-driven microturbine that is capable of providing autonomous propulsion in which the rapidly moving gases are directed through a micromachined turbine to power mechanical, electrical, or electromechanical devices by direct mechanical linkage of turbo-electric generator components in a domain ranging from tenths of micrometers to thousands of micrometers. By optimally selecting monopropellants or bipropellants to be the fuel set, a more efficient gas-driven microturbine can be realized from the increased mass flow rate of the gas stream due to the higher combustion reaction energies of these fuel sets. Additionally, compressed gas can be utilized to provide a high-flow gas stream for the gas-driven microturbine. The present invention is adaptable to many defense and non-defense applications, including the provision of mechanical power for miniature devices such as fans, geared mechanisms, mechanical linkages, actuators, bio-medical procedures, manufacturing, industrial, aviation, computers, safety systems, and electrical generators.
Date: July 14, 1999
Creator: Sniegowski, Jeffrey J.; Rodgers, Murray S.; McWhorter, Paul J.; Aeschliman, Daniel P. & Miller, William M.
System: The UNT Digital Library
Highly conductive electrolyte composites and method of fabrication thereof (open access)

Highly conductive electrolyte composites and method of fabrication thereof

An electrolyte composite is manufactured by pressurizing a mixture of ionically conductive glass and an ionically conductive compound at between 12,000 and 24,000 pounds per square inch to produce a pellet. The resulting pellet is then sintered at relatively lower temperatures (800{degrees}C--1200{degrees}C), for example 1000{degrees}C, than are typically required (1400{degrees}C) when fabricating single constituent ceramic electrolytes. The resultant composite is 100 percent conductive at 250{degrees}C with conductivity values of 2.5 to 4 {times} 10{sup {minus}2} (ohm-cm){sup {minus}1}. The matrix exhibits chemical stability against sodium for 100 hours at 250 to 300{degrees}C.
Date: July 17, 1990
Creator: Hash, M. C. & Bloom, I. D.
System: The UNT Digital Library
Hyper filter-fluorescer spectrometer for x rays above 120 keV (open access)

Hyper filter-fluorescer spectrometer for x rays above 120 keV

An apparatus utilizing filter-fluorescer combinations is provided to measure short bursts of high fluence x-rays above 120 keV energy, where there are no practical absorption edges available for conventional filter-fluorescer techniques. The absorption edge of the prefilter is chosen to be less than that of the fluorescer, i.e., E/sub PRF/ < E/sub F/, contrary to the prior art technique E/sub PRF/ > E/sub F/. In this way, the response function is virtually zero between E/sub PRF/ and E/sub F/ and well defined and enhanced in an energy band of less than 1000 keV above the 120 keV energy.
Date: July 7, 1981
Creator: Wang, C. L.
System: The UNT Digital Library
Improved Consolidation Process for Producing Ceramic Waste forms (open access)

Improved Consolidation Process for Producing Ceramic Waste forms

A process for the consolidation and containment of solid or semisolid hazardous waste, which process comprises closing an end of a circular hollow cylinder, filling the cylinder with the hazardous waste, and then cold working the cylinder to reduce its diameter while simultaneously compacting the waste. The open end of the cylinder can be sealed prior to or after the cold working process. The preferred method of cold working is to draw the sealed cylinder containing the hazardous waste through a plurality of dies to simultaneously reduce the diameter of the tube while compacting the waste. This process provides a quick continuous process for consolidating hazardous waste, including radioactive waste.
Date: July 24, 1998
Creator: Hash, Harry C. & Hash, Mark C.
System: The UNT Digital Library
Improved solvent extraction recovery of shale oil. [DOE patent application] (open access)

Improved solvent extraction recovery of shale oil. [DOE patent application]

An improved process for solvent extraction of organic matter from shale by two extraction steps in sequence. The extraction steps are: (1) treating a kerogen-containing shale with a solvent system comprising a combination of water and an alcohol at a temperature of about 375 to 425/sup 0/C; and (2) treating the product of (1) with a solvent system comprising a combination of an alcohol and another organic solvent at an elevated temperature, but not above about 425/sup 0/C. The organic matter is recovered by separating the liquid which results from step (2) from the shale solids.
Date: July 20, 1981
Creator: McKay, John F. & Chong, Shuang-Ling
System: The UNT Digital Library
In-Line Thermoelectric Module (open access)

In-Line Thermoelectric Module

A thermoelectric module with a plurality of electricity generating units each having a first end and a second end, the units being arranged first end to second end along an-in-line axis. Each unit includes first and second elements each made of a thermoelectric material, an electrically conductive hot member arranged to heat one side of the first element, and an electrically conductive cold member arranged to cool another side of the first element and to cool one side of the second element. The hot member, the first element, the cold member and the second element are supported in a fixture, are electrically connected respectively to provide an electricity generating unit, and are arranged respectively in positions along the in-line axis. The individual components of each generating unit and the respective generating units are clamped in their in-line positions by a loading bolt at one end of the fixture and a stop wall at the other end of the fixture. The hot members may have a T-shape and the cold members an hourglass shape to facilitate heat transfer. The direction of heat transfer through the hot members may be perpendicular to the direction of heat transfer through the cold members, and …
Date: July 28, 1998
Creator: Pento, Robert; Marks, James E. & Staffanson, Clifford D.
System: The UNT Digital Library
Magnetic testing probe (open access)

Magnetic testing probe

A cylindrical eddy current tube testing probe is disclosed. Current flow in dual electromagnetic coils separated by an eddy current sensing coil is so directed that magnetic fields of the electromagnet coils have components extending in opposite directions axially of the tested tube and components extending radially of the tube which add in the region of the eddy current sensing coil.
Date: July 7, 1981
Creator: Scott, G.W. & Chitwood, L.D.
System: The UNT Digital Library
Method and apparatus for measuring flow velocity using matched filters (open access)

Method and apparatus for measuring flow velocity using matched filters

An apparatus and method for measuring the flow velocities of individual phase flow components of a multiphase flow is disclosed. Signals arising from flow noise disturbance are extracted from the flow, at upstream and downstream locations. The signals are processed through pairs of matched filters which are matched to the flow disturbance frequency characteristics of the phase flow component to be measured. The processed signals are then cross-correlated to determine the transit delay time of the phase flow component between sensing positions.
Date: July 17, 1981
Creator: Raptis, A. C.
System: The UNT Digital Library
Method for determining the hardness of strain hardening articles of tungsten-nickel-iron alloy (open access)

Method for determining the hardness of strain hardening articles of tungsten-nickel-iron alloy

The present invention is directed to a rapid nondestructive method for determining the extent of strain hardening in an article of tungsten-nickel-iron alloy. The method comprises saturating the article with a magnetic field from a permanent magnet, measuring the magnetic flux emanating from the article, comparing the measurements of the magnetic flux emanating from the article with measured magnetic fluxes from similarly shaped standards of the alloy with known amounts of strain hardening to determine the hardness.
Date: July 29, 1981
Creator: Wallace, S.A.
System: The UNT Digital Library
Method for fabricating a seal between a ceramic and a metal alloy (open access)

Method for fabricating a seal between a ceramic and a metal alloy

A method of fabricating a seal between a ceramic and an alloy comprising the steps of prefiring the alloy in an atmosphere with a very low partial pressure of oxygen, firing the assembled alloy and ceramic in air, and gradually cooling the fired assembly to avoid the formation of thermal stress in the ceramic. The method forms a bond between the alloy and the ceramic capable of withstanding the environment of a pressurized water reactor and suitable for use in an electrical conductivity sensitive liquid level transducer.
Date: July 24, 1981
Creator: Kelsey, P.V. Jr. & Siegel, W.T.
System: The UNT Digital Library
Method for generating a highly reactive plasma for exhaust gas after treatment and enhanced catalyst reactivity (open access)

Method for generating a highly reactive plasma for exhaust gas after treatment and enhanced catalyst reactivity

This patent application describes a method and apparatus of exhaust gas remediation that enhance the reactivity of the material catalysts found within catalytic converters of cars, trucks, and power stations.
Date: July 1, 2000
Creator: Whealton, John H.; Hanson, Gregory R.; Storey, John M.; Raridon, Richard J.; Armfield, Jeffrey S.; Bigelow, Timothy S. et al.
System: The UNT Digital Library
Method of Determining the Extent to which a Nickel Structure has been Attached by a Fluorine-Containing Gas (open access)

Method of Determining the Extent to which a Nickel Structure has been Attached by a Fluorine-Containing Gas

The method of determining the extent to which a nickel structure has been attacked by a halogen containing gas to which it has been exposed which comprises preparing a quantity of water substantially free from dissolved oxygen, passing ammonia gas through a cuprammonium solution to produce ammonia substantially free from oxygen, dissolving said oxygen-free ammonia in said water to produce a saturated aqueous ammonia solution free from uncombined oxygen, treating at least a portion of said nickel structure of predetermined weight with said solution to dissolve nickel compounds from the surface of said structure without dissolving an appreciable amount of said nickel and analyzing the resulting solution to determine the quantity of said nickel compounds that was associated with said said portion of said structure to determine the proportion of combined nickel in said nickel structure.
Date: July 13, 2004
Creator: Brusie, James P.
System: The UNT Digital Library
Method to Remove Uranium/Vanadium Contamination from Groundwater (open access)

Method to Remove Uranium/Vanadium Contamination from Groundwater

A process for removing uranium/vanadium-based contaminants from groundwater using a primary in-ground treatment media and a pretreatment media that chemically adjusts the groundwater contaminant to provide for optimum treatment by the primary treatment media.
Date: July 27, 2004
Creator: Metzler, Donald R. & Stanley, Morrison
System: The UNT Digital Library
Neutron and gamma radiation shielding material, structure, and process of making structure (open access)

Neutron and gamma radiation shielding material, structure, and process of making structure

The present invention is directed to a novel neutron and gamma radiation shielding material consisting of 95 to 97% by weight SiO/sub 2/ and 5 to 3% by weight sodium silicate. In addition, the method of using this composition to provide a continuous neutron and gamma radiation shielding structure is disclosed.
Date: July 6, 1981
Creator: Hondorp, H.L.
System: The UNT Digital Library
One-piece, composite crucible with integral withdrawal/discharge section (open access)

One-piece, composite crucible with integral withdrawal/discharge section

A one-piece, composite open-bottom casting mold with integral withdrawal section is fabricated by thermal spraying of materials compatible with and used for the continuous casting of shaped products of reactive metals and alloys such as, for example, titanium and its alloys or for the gas atomization thereof.
Date: July 30, 2002
Creator: Besser, Matthew; Terpstra, Robert L. (Iowa State Univ., Ames, IA); Sordelet, Daniel J.; Anderson, Iver E.; Hartman, Alan D.; Argetsinger, Edward R. et al.
System: The UNT Digital Library
Optical State-of-Change Monitor for Lead-Acid Batteries (open access)

Optical State-of-Change Monitor for Lead-Acid Batteries

A method and apparatus for determining the instantaneous state-of-charge of a battery in which change in composition with discharge manifests itself as a change in optical absorption. In a lead-acid battery, the sensor comprises a fiber optic system with an absorption cdl or, alternatively, an optical fiber woven into an absorbed-glass-mat battery. In a lithium-ion battery, the sensor comprises fiber optics for introducing light into the anode to monitor absorption when lithium ions are introduced.
Date: July 24, 1998
Creator: Weiss, Jonathan D.
System: The UNT Digital Library
Plasma channel optical-pumping device and method (open access)

Plasma channel optical-pumping device and method

A device and method are described for optically pumping a gaseous laser using blackbody radiation produced by a plasma channel which is formed from an electrical discharge between two electrodes spaced at opposite longitudinal ends of the laser. A preionization device which can comprise a laser or electron beam accelerator produces a preionization beam which is sufficient to cause an elctrical discharge between the electrodes to initiate the plasma channel along the preionization path. The optical pumping energy is supplied by a high voltage power supply rather than by the preionization beam. High output optical intensities are produced by the laser due to the high temperature black-body radiation produced by the plasma channel, in the same manner as an exploding wire type laser. However, unlike the exploding wire type laser, the disclosed invention can be operated in a repetitive manner by utilizing a repetitive pulsed preionization device.
Date: July 17, 1981
Creator: Judd, O.P.
System: The UNT Digital Library
Portable vacuum object handling device (open access)

Portable vacuum object handling device

The disclosure relates to a portable device adapted to handle objects which are not to be touched by hand. A piston and bore wall form a vacuum chamber communicating with an adaptor sealably engageable with an object to be lifted. The piston is manually moved and set to establish vacuum. A valve is manually actuable to apply the vacuum to lift the object.
Date: July 30, 1981
Creator: Anderson, G.H.
System: The UNT Digital Library
Pressure Gradient Passivation of Carbonaceous Material Normally Susceptible to Spontaneous Combustion (open access)

Pressure Gradient Passivation of Carbonaceous Material Normally Susceptible to Spontaneous Combustion

This invention is a process for the passivation or deactivation with respect to oxygen of a carbonaceous material by the exposure of the carbonaceous material to an oxygenated gas in which the oxygenated gas pressure is increased from a first pressure to a second pressure and then the pressure is changed to a third pressure. Preferably a cyclic process which comprises exposing the carbonaceous material to the gas at low pressure and increasing the pressure to a second higher pressure and then returning the pressure to a lower pressure is used. The cycle is repeated at least twice wherein the higher pressure may be increased after a selected number of cycles.
Date: July 15, 1999
Creator: Ochs, Thomas L.; Sands, William D.; Schroeder, Karl; Summers, Cathy A. & Utz, Bruce R.
System: The UNT Digital Library
Process for fabrication of metal oxide films (open access)

Process for fabrication of metal oxide films

This invention is comprised of a method of fabricating metal oxide films from a plurality of reactants by inducing a reaction by plasma deposition among the reactants. The plasma reaction is effective for consolidating the reactants and producing thin films of metal oxides, e.g. electro-optically active transition metal oxides, at a high deposition rate. The presence of hydrogen during the plasma reaction enhances the deposition rate of the metal oxide. Various types of metal oxide films can be produced.
Date: July 17, 1990
Creator: Tracy, C. E.; Benson, D. & Svensson, S.
System: The UNT Digital Library