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Reactor refueling containment system

Description: This report describes a method of refueling a nuclear reactor whereby the drive mechanism is disengaged and removed by activating a jacking mechanism that raises the closure head. The area between the barrier plate and closure head is exhausted through the closure head penetrations. The closure head, upper drive mechanism, and bellows seal are lifted away and transported to a safe area. The barrier plate acts as the primary boundary and each drive and control rod penetration has an elastomer seal preventing excessive tritium gases from escaping. The individual instrumentation plugs are disengaged allowing the corresponding fuel assembly to be sealed and replaced.
Date: December 31, 1992
Creator: Gillett, J.E. & Meuschke, R.E.
Partner: UNT Libraries Government Documents Department

Insensitive explosive

Description: This invention relates to the field of chemistry and, more particularly, to explosives. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36). It is desirable to use explosives in weapons and other applications which are less sensitive than the common explosives RDX, TNT, and HMX, since there have been catastrophic explosions of munitions which use these compounds. In preliminary characterization and sensitivity testing, it has been found that 3-amino-5-nitro-1,2,4-triazole (ANTA) is a promising insensitive high explosive. This report details the safety, production, and physical properties of ANTA.
Date: December 31, 1991
Creator: Lee, Kien-yin & Storm, C.B.
Partner: UNT Libraries Government Documents Department

Irreversible magnetic switch

Description: This invention is comprised of an irreversible magnetic switch containing a ferromagnetic amorphous metal having a predetermined crystallization temperature in its inductor magnetic path. With the incorporation of such material, the magnetic properties after cooling from a high temperature excursion above its crystallization temperature are only a fraction of the original value. The difference is used to provide a safety feature in the magnetic switch.
Date: December 31, 1991
Creator: Karnowsky, M. M. & Yost, F. G.
Partner: UNT Libraries Government Documents Department

Method and apparatus for detecting timing errors in a system oscillator

Description: This invention is comprised of a method of detecting timing errors in a system oscillator for an electronic device, such as a power supply, includes the step of comparing a system oscillator signal with a delayed generated signal and generating a signal representative of the timing error when the system oscillator signal is not identical to the delayed signal. An LED indicates to an operator that a timing error has occurred. A hardware circuit implements the above-identified method.
Date: December 31, 1991
Creator: Gliebe, R.J. & Kramer, W.R.
Partner: UNT Libraries Government Documents Department

Method for simultaneous measurement of mass loading and fluid property changes using a quartz crystal microbalance

Description: A method, using a quartz crystal microbalance, to obtain simultaneous measurement of solid mass accumulation and changes in liquid density-viscosity product. The simultaneous real-time measurements of electrical parameters yields that changes in surface mass can be differentiated from changes in solution properties. Two methods to obtain the admittance/frequency data are employed.
Date: December 31, 1991
Creator: Granstaff, V.E. & Martin, S.J.
Partner: UNT Libraries Government Documents Department

Micromachined silicon electrostatic chuck

Description: In the field of microelectronics, and in particular the fabrication of microelectronics during plasma etching processes, electrostatic chucks have been used to hold silicon wafers during the plasma etching process. Current electrostatic chucks that operate by the {open_quotes}Johnson-Rahbek Effect{close_quotes} consist of a metallic base plate that is typically coated with a thick layer of slightly conductive dielectric material. A silicon wafer of approximately the same size as the chuck is placed on top of the chuck and a potential difference of several hundred volts is applied between the silicon and the base plate of the electrostatic chuck. This causes an electrostatic attraction proportional to the square of the electric field in the gap between the silicon wafer and the chuck face. When the chuck is used in a plasma filled chamber the electric potential of the wafer tends to be fixed by the effective potential of the plasma. The purpose of the dielectric layer on the chuck is to prevent the silicon wafer from coming into direct electrical contact with the metallic part of the chuck and shorting out the potential difference. On the other hand, a small amount of conductivity appears to be desirable in the dielectric coating so that much of its free surface between points of contact with the silicon wafer is maintained near the potential of the metallic base plate; otherwise, a much larger potential difference would be needed to produce a sufficiently large electric field in the vacuum gap between the wafer and chuck. Typically, the face of the chuck has a pattern of grooves in which about 10 torr pressure of helium gas is maintained. This gas provides cooling (thermal contact) between the wafer and the chuck. A pressure of 10 torr is equivalent to about 0.2 psi.
Date: December 31, 1994
Creator: Anderson, R.A. & Seager, C.H.
Partner: UNT Libraries Government Documents Department

Multiple-frequency acoustic wave devices for chemical sensing and materials characterization in both gas and liquid phase

Description: This invention consists of a chemical sensor that includes two or more pairs of interdigital electrodes having different periodicities. Each pair is comprised of a first electrode and a second electrode. The electrodes are patterned on a surface of a piezoelectric substrate. Each pair of electrodes may launch and receive various acoustic waves (AW), including a surface acoustic wave (SAW), and may also launch and receive several acoustic plate modes (APMs). The frequencies associated with each are functions of the transducer periodicity as well as the velocity of the particular AW in the chosen substrate material. An AW interaction region exists between each pair of electrodes. Circuitry is used to launch, receive, and monitor the propagation characteristics of the AWs and may be configured in an intermittent measurement fashion or in a continuous measurement fashion. Perturbations to the AW velocity and attenuation are recorded at several frequencies and provide the sensor response.
Date: December 31, 1991
Creator: Martin, S. J. & Ricco, A. J.
Partner: UNT Libraries Government Documents Department

Pneumatic solids feeder for coal gasification reactor

Description: This invention is comprised of a pneumatic feeder system for a coal gasification reactor which includes one or more feeder tubes entering the reactor above the level of the particle bed inside the reactor. The tubes are inclined downward at their outer ends so that coal particles introduced into the tubes through an aperture at the top of the tubes slides downward away from the reactor and does not fall directly into the reactor. Pressurized gas introduced into, or resulting from ignition of recycled combustible gas in a chamber adjacent to the tube ends, propels the coal from the tube into the reactor volume and onto the particle bed. Leveling of the top of the bed is carried out by a bladed rotor mounted on the reactor stirring shaft. Coal is introduced into the tubes from containers above the tubes by means of rotary valves placed across supply conduits. This system avoids placement of feeder hardware in the plenum above the particle bed and keeps the coal from being excessively heated prior to reaching the particle bed.
Date: December 31, 1991
Creator: Notestein, J. E. & Halow, J. S.
Partner: UNT Libraries Government Documents Department

Process for the recovery of strontium from acid solutions

Description: The invention is a process for selectively extracting strontium and technetium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant is a macrocyclic polyether in a diluent which is insoluble in water, but which will itself dissolve a small amount of water. The process will extract strontium and technetium values from nitric acid solutions which are up to 6 molar in nitric acid.
Date: December 31, 1990
Creator: Horwitz, E. P. & Dietz, M. L.
Partner: UNT Libraries Government Documents Department

Reactive multilayer synthesis of hard ceramic foils and films

Description: Disclosed is method for synthesizing hard ceramic materials such as carbides, borides and aluminides, particularly in the form of coatings provided on another material so as to improve the wear and abrasion performance of machine tools, for example. Method involves the sputter deposition of alternating layers of reactive metals with layers of carbon, boron, or aluminum and the subsequent reaction of the multilayered structure to produce a dense crystalline ceramic. The material can be coated on a substrate or formed as a foil which can be coiled as a tape for later use.
Date: December 31, 1993
Creator: Makowiecki, D.M. & Holt, J.B.
Partner: UNT Libraries Government Documents Department

Underwater manipulator

Description: This invention is comprised of a self-contained, waterproof, water-submersible, remote-controlled apparatus provided for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer {plus_minus} 45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer {plus_minus} 10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.
Date: December 31, 1992
Creator: Schrum, P.B. & Cohen, G.H.
Partner: UNT Libraries Government Documents Department

Small system for tritium accelerator mass spectrometry

Description: This invention is comprised of an apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radiofrequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and {sup 3}He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.
Date: December 31, 1991
Creator: Roberts, M.L. & Davis, J.C.
Partner: UNT Libraries Government Documents Department

Superconducting thermoelectric generator

Description: This invention is comprised of an apparatus and method for producing electricity from heat. The present invention is a thermoelectric generator that uses materials with substantially no electrical resistance, often called superconductors, to efficiently convert heat into electrical energy without resistive losses. Preferably, an array of superconducting elements is encased within a second material with a higher thermal conductivity than that of the superconducting material. The second material is preferably a semiconductor. Alternatively, the superconducting material can be doped on a base semiconducting material, or the superconducting material and the semiconducting material can exist as alternating, interleaved layers of waferlike materials. A temperature gradient imposed across the boundary of the two materials, establishes an electrical potential related to the magnitude of the temperature gradient. The superconducting material carries the resulting electrical current at zero resistivity, thereby eliminating resistive losses. The elimination of resistive losses significantly increases the conversion efficiency of the thermoelectric device.
Date: December 31, 1992
Creator: Metzger, J.D. & El-Genk, M.
Partner: UNT Libraries Government Documents Department

Supported liquid membrane system

Description: A cell apparatus for a supported liquid membrane including opposing faceplates, each having a spirally configured groove, an inlet groove at a first end of the spirally configured groove, and an outlet groove at the other end of the spirally configured groove, within the opposing faces of the faceplates, a microporous membrane situated between the grooved faces of the faceplates, said microporous membrane containing an extractant mixture selective for a predetermined chemical species within the pores of said membrane, means for aligning the grooves of the faceplates in an directly opposing configuration with the porous membrane being situated therebetween, such that the aligned grooves form a pair of directly opposing channels, separate feed solution and stripping solution compartments connected to respective channels between the faceplates and the membrane, separate pumping means for passing feed solution and stripping solution through the channels is provided.
Date: December 31, 1990
Creator: Takigawa, D. Y. & Bush, H. Jr.
Partner: UNT Libraries Government Documents Department

Traveling-wave photodetector

Description: The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.
Date: December 31, 1992
Creator: Hietala, V. M. & Vawter, G. A.
Partner: UNT Libraries Government Documents Department

Visual cluster analysis and pattern recognition template and methods

Description: This invention is comprised of a method of clustering using a novel template to define a region of influence. Using neighboring approximation methods, computation times can be significantly reduced. The template and method are applicable and improve pattern recognition techniques.
Date: December 31, 1993
Creator: Osbourn, G.C. & Martinez, R.F.
Partner: UNT Libraries Government Documents Department

Wedge and spring assembly for securing coils in electromagnets and dynamoelectric machines

Description: A wedge and spring assembly for use in electromagnets or dynamoelectric machines having a housing with an axis therethrough and a plurality of coils supported on salient poles that extend radially inward from the housing toward the housing axis to define a plurality of interpole spaces, respectively between the housing and adjacent coils, the interpole spaces each extending in a direction generally parallel to the housing axis. The wedge and spring assembly includes a nonmagnetic retainer spring and a nonmagnetic wedge. The retainer spring is formed to fit into one of the interpole spaces, and has juxtaposed ends defining between them a slit extending in a direction generally parallel to the housing axis. The wedge for insertion into the slit provides an outwardly directed force on respective portions of the juxtaposed ends defining the slit to expand the slit so that respective portions of the retainer spring engage areas of the coils adjacent thereto, thereby resiliently holding the coils against their respective salient poles. Preferably, the spring retainer and wedge are self-locking wherein wedge is fabricated from a material softer than a material the retainer spring is fabricated from, so that the wedge is securely retained in the slit. The retainer spring is generally triangular shaped to fit within the interpole space and fabricated from berryllium-copper alloy, and the wedge is generally T-shaped and fabricated from aluminum. Alternatively, a wedge and spring assembly includes a wedge having divergent sloped surfaces in which each surface and the respective juxtaposed ends of the retainer spring are angled relative to one another so that the wedge is securely retained in the slit by friction existing between its sloped surfaces and the juxtaposed ends of the retaining spring.
Date: December 31, 1994
Creator: Lindner, M. & Cottingham, J.G.
Partner: UNT Libraries Government Documents Department

An ion source based on the cathodic arc

Description: This invention is comprised of a cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated. An array of electrically isolated rings positioned in the source serves the duel purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles.
Date: December 31, 1992
Creator: Sanders, D. M. & Falabella, S.
Partner: UNT Libraries Government Documents Department

Laser patterning of laminated structures for electroplating

Description: Disclosed is a process for laser patterning of a substrate so that it can be subsequently electroplated or electrolessly plated. The process utilizes a laser to treat an inactive (inert) layer formed over an active layer to either combine or remove the inactive layer to produce a patterned active layer on which electrodeposition can occur. The process is carried out by utilizing laser alloying and laser etching, and involves only a few relatively high yield steps and can be performed on a very small scale.
Date: December 31, 1992
Creator: Mayer, S. T. & Evans, L. B.
Partner: UNT Libraries Government Documents Department

Method and apparatus for providing pulse pile-up correction in charge quantizing radiation detection systems

Description: This invention is comprised of a radiation detection method and system for continuously correcting the quantization of detected charge during pulse pile-up conditions. Charge pulses from a radiation detector responsive to the energy of detected radiation events are converted to voltage pulses of predetermined shape whose peak amplitudes are proportional to the quantity of charge of each corresponding detected event by means of a charge-sensitive preamplifier. These peak amplitudes are sampled and stored sequentially in accordance with their respective times of occurrence. Based on the stored peak amplitudes and times of occurrence, a correction factor is generated which represents the fraction of a previous pulses influence on a preceding pulse peak amplitude. This correction factor is subtracted from the following pulse amplitude in a summing amplifier whose output then represents the corrected charge quantity measurement.
Date: December 31, 1992
Creator: Britton, C.L. Jr. & Wintenberg, A.L.
Partner: UNT Libraries Government Documents Department

Method of separating organic contaminants from fluid feedstreams with polyphosphazene membranes

Description: A method is provided for separating polar hydrocarbons from a fluid feedstream. The fluid feedstream is flowed across a first surface of a polyphosphazene semipermeable membrane. At least one polar hydrocarbon from the fluid feedstream permeates through the polyphosphazene semipermeable membrane to a second opposed surface of the semipermeable membrane. Then the permeated polar hydrocarbon is removed from the second opposed surface of the polyphosphazene semipermeable membrane. Outstanding and unexpected separation selectivities on the order of 10,000 were obtained for methylene chloride when a methylene chloride in water feedstream was flowed across the polyphosphazene semipermeable membrane in the invented method.
Date: December 31, 1990
Creator: McCaffrey, R. R. & Cummings, D. G.
Partner: UNT Libraries Government Documents Department

Microwave sintering of multiple aritcles

Description: Disclosed are apparatus and method for producing articles of alumina and of alumina and silicon carbide in which the articles are sintered at high temperatures using microwave radiation. The articles are placed in a sintering container which is placed in a microwave cavity for heating. The rates at which heating and cooling take place is controlled.
Date: December 31, 1992
Creator: Blake, R. D. & Katz, J. D.
Partner: UNT Libraries Government Documents Department

Improved fracture toughness for copper oxide superconductors

Description: An oxide-based strengthening and toughening agent, such as tetragonal Zro{sub 2} particles, has been added to copper oxide superconductors, such as superconducting YBa{sub 2}Cu{sub 3}O{sub x} (123) to improve it fracture toughness (K{sub IC}). A sol-gel coating which is non-reactive with the superconductor, such as Y{sub 2}BaCuO{sub 5} (211) on the ZrO{sub 2} particles minimized the deleterious reactions between the superconductor and the toughening agent dispersed therethrough. Addition of 20 mole percent ZrO{sub 2} coated with 211 yielded a 123 composite with a K{sub IC} of 4.5 MPa(m){sup 0.5}.
Date: December 31, 1991
Creator: Goretta, K.C. & Kullberg, M.L.
Partner: UNT Libraries Government Documents Department

Low-temperature hermetic sealing of optical fiber components

Description: A method for manufacturing low-temperature hermetically sealed optical fiber components is provided. The method comprises the steps of: inserting an optical fiber into a housing, the optical fiber having a glass core, a glass cladding and a protective buffer layer disposed around the core and cladding; heating the housing to a predetermined temperature, the predetermined temperature being below a melting point for the protective buffer layer and above a melting point of a solder; placing the solder in communication with the heated housing to allow the solder to form an eutectic and thereby fill a gap between the interior of the housing and the optical fiber; and cooling the housing to allow the solder to form a hermetic compression seal between the housing and the optical fiber.
Date: December 31, 1995
Creator: Kramer, Daniel P.
Partner: UNT Libraries Government Documents Department