13 Matching Results

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Tritium monitor and collection system (open access)

Tritium monitor and collection system

This system measures tritium on-line and collects tritium from a flowing inert gas stream. It separates the tritium from other non-hydrogen isotope contaminating gases, whether radioactive or not. The collecting portion of the system is constructed of various zirconium alloys called getters. These alloys adsorb tritium in any of its forms at one temperature and at a higher temperature release it as a gas. The system consists of four on-line getters and heaters, two ion chamber detectors, two collection getters, and two guard getters. When the incoming gas stream is valved through the on-line getters, 99.9% of it is adsorbed and the remainder continues to the guard getter where traces of tritium not collected earlier are adsorbed. The inert gas stream then exits the system to the decay chamber. Once the on-line getter has collected tritium for a predetermined time, it is valved off and the next online getter is valved on. Simultaneously, the first getter is heated and a pure helium purge is employed to carry the tritium from the getter. The tritium loaded gas stream is then routed through an ion chamber which measures the tritium activity. The ion chamber effluent passes through a collection getter that readsorbs …
Date: March 26, 1991
Creator: Baker, J. D.; Wickham, K. L.; Ely, W. E.; Tuggle, D. G.; Meikrantz, D. H.; Grafwaller, E. G. et al.
System: The UNT Digital Library
Linear electric field mass spectrometry (open access)

Linear electric field mass spectrometry

A mass spectrometer is described having a low weight and low power requirement, for use in space. It can be used to analyze the ionized particles in the region of the spacecraft on which it is mounted. High mass resolution measurements are made by timing ions moving through a gridless cylindrically sysmetric linear electric field.
Date: March 29, 1991
Creator: McComas, D. J. & Nordholt, J. E.
System: The UNT Digital Library
Sterilization of fermentation vessels by ethanol/water mixtures (open access)

Sterilization of fermentation vessels by ethanol/water mixtures

This invention is comprised of a method for sterilizing process fermentation vessels with a concentrated alcohol and water mixture integrated in a fuel alcohol or other alcohol production facility. Hot, concentrated alcohol is drawn from a distillation or other purification stage and sprayed into the empty fermentation vessels. This sterilizing alcohol/water mixture should be of a sufficient concentration, preferably higher than 12% alcohol by volume, to be toxic to undesirable microorganisms. Following sterilization, this sterilizing alcohol/water mixture can be recovered back into the same distillation or other purification stage from which it was withdrawn. The process of this invention has its best application in, but is not limited to, batch fermentation processes, wherein the fermentation vessels must be emptied, cleaned, and sterilized following completion of each batch fermentation process.
Date: March 20, 1991
Creator: Wyman, C. E.
System: The UNT Digital Library
Process for strengthening silicon based ceramics (open access)

Process for strengthening silicon based ceramics

A process for strengthening silicon based ceramic monolithic materials and composite materials that contain silicon based ceramic reinforcing phases that requires that the ceramic be exposed to a wet hydrogen atmosphere at about 1400{degrees}C. The process results in a dense, tightly adherent silicon containing oxide layer that heals, blunts, or otherwise negates the detrimental effect of strength limiting flaws on the surface of the ceramic body.
Date: March 7, 1991
Creator: Kim, Hyoun-Ee & Moorhead, A. J.
System: The UNT Digital Library
Precision surface machining (open access)

Precision surface machining

Precision finishing apparatus utilizing line contact polishing to produce optical quality parts. A rotatable cylinder is horizontally disposed above a workpiece which is mounted on a rotatable, and horizontally and vertically adjustable chuck. Predetermined surfaces can be cut into the surface of the cylinder to produce figures of revolution, such as aspheres,, when the workpiece is being rotated.
Date: March 6, 1991
Creator: Lazazzera, Vito J. & Schmell, Rodney A.
System: The UNT Digital Library
Chemotactic selection of pollutant degrading soil bacteria (open access)

Chemotactic selection of pollutant degrading soil bacteria

A method is described for identifying soil microbial strains which may be bacterial degraders of pollutants. This method includes: Placing a concentration of a pollutant in a substantially closed container; placing the container in a sample of soil for a period of time ranging from one minute to several hours; retrieving the container and collecting its contents; microscopically determining the identity of the bacteria present. Different concentrations of the pollutant can be used to determine which bacteria respond to each concentration. The method can be used for characterizing a polluted site or for looking for naturally occurring biological degraders of the pollutant. Then bacteria identified as degraders of the pollutant and as chemotactically attracted to the pollutant are used to innoculate contaminated soil. To enhance the effect of the bacteria on the pollutant, nutrients are cyclicly provided to the bacteria then withheld to alternately build up the size of the bacterial colony or community and then allow it to degrade the pollutant.
Date: March 4, 1991
Creator: Hazen, T. C.
System: The UNT Digital Library
Amorphous silicon/polycrystalline thin film solar cells (open access)

Amorphous silicon/polycrystalline thin film solar cells

An improved photovoltaic solar cell is described including a p-type amorphous silicon layer, intrinsic amorphous silicon, and an n-type polycrystalline semiconductor such as cadmium sulfide, cadmium zinc sulfide, zinc selenide, gallium phosphide, and gallium nitride. The polycrystalline semiconductor has an energy bandgap greater than that of the amorphous silicon. The solar cell can be provided as a single-junction device or a multijunction device.
Date: March 13, 1991
Creator: Ullal, H. S.
System: The UNT Digital Library
Magnetron sputtered boron films and Ti/B multilayer structures (open access)

Magnetron sputtered boron films and Ti/B multilayer structures

A method is described for the production of thin boron and titanium/boron films by magnetron sputter deposition. The amorphous boron films contain no morphological growth features, unlike those found when thin films are prepared by various physical vapor 5 deposition processes. Magnetron sputter deposition method requires the use of a high density crystalline boron sputter target which is prepared by hot isostatic pressing. Thin boron films prepared by this method are useful for ultra-thin band pass filters as well as the low Z element in low Z/high Z mirrors which enhance reflectivity 10 from grazing to normal incidence.
Date: March 11, 1991
Creator: Makowiecki, Daniel Matthew & Jankowski, Alan Frederic
System: The UNT Digital Library
Apparatus and method for critical current measurements (open access)

Apparatus and method for critical current measurements

An apparatus for the measurement of the critical current of a superconductive sample, e.g., a clad superconductive sample, the apparatus including a conductive coil, a means for maintaining the coil in proximity to a superconductive sample, an electrical connection means for passing a low amplitude alternating current through the coil, a cooling means for maintaining the superconductive sample at a preselected temperature, a means for passing a current through the superconductive sample, and, a means for monitoring reactance of the coil. The alternating current capable of generating a magnetic field sufficient to penetrate, e.g., any cladding, and to induce eddy currents in the superconductive material, passing a steadily increasing current through the superconductive material, the current characterized as having a different frequency than the alternating current, and, monitoring the reactance of the coil with a phase sensitive detector as the current passed through the superconductive material is steadily increased whereby critical current of the superconductive material can be observed as the point whereat a component of impedance deviates.
Date: March 15, 1991
Creator: Martin, J. A. & Dye, R. C.
System: The UNT Digital Library
Optical transcutaneous bilirubin detector (open access)

Optical transcutaneous bilirubin detector

This invention consists of a transcutaneous bilirubin detector comprising a source of light having spectral components absorbable and not absorbable by bilirubin, a handle assembly, electronic circuitry and a fiber optic bundle connecting the assembly to the light source and circuitry. Inside the assembly is a prism that receives the light from one end of the fiber optic bundle and directs it onto the skin and directs the reflected light back into the bundle. The other end of the bundle is trifucated, with one end going to the light source and the other two ends going to circuitry that determines how much light of each kind has been reflected. A relatively greater amount absorbed by the skin from the portion of the spectrum absorbable by bilirubin may indicate the presence of the illness. Preferably, two measurements are made, one on the kneecap and one on the forehead, and compared to determine the presence of bilirubin. To reduce the impact of light absorption by hemoglobin in the blood carried by the skin, pressure is applied with a plunger and spring in the handle assembly, the pressure limited by points of a button slidably carried in the assembly that are perceived by …
Date: March 4, 1991
Creator: Kronberg, J. W.
System: The UNT Digital Library
Ringlight for use in high radiation (open access)

Ringlight for use in high radiation

The present invention relates generally to ringlight for providing illumination about a central viewing area and more particularly to an improved ringlight design suitable for use in automatic gaging applications conducted in hostile radioactive environments. It is a further object of the present invention to provide a ringlight which is relatively simple in construction and with few parts, and which is thus very reliable in operation. The above and other objects are achieved in the present invention by a ringlight providing an annular array of light-emitting elements centered about a viewing passage, wherein the improvement comprises: a first annular body, a second annular body mounted concentrically within the first annular body so as to form an annular void and light-emitting aperture therebetween, and a plurality of optical fibers extending into the void with end portions thereof secured therein so as to form an annular array of optical fiber end surfaces at said light-emitting aperture, the first and second bodies cooperating to angle the end portions of the plurality of optical fibers toward a central axis of the viewing passage.
Date: March 6, 1991
Creator: Baylor, G. A. & Jacket, H. S.
System: The UNT Digital Library
Integrated process for reprocessing spent nuclear fuel (open access)

Integrated process for reprocessing spent nuclear fuel

This invention is comprised of a process for recovering nuclear fuel from spent fuel assemblies that employs a single canister process container. The cladding and fuel are oxidized in the container, the fuel is dissolved and removed from the container for separation from the aqueous phase, the aqueous phase containing radioactive waste is returned to the container. This container is also the disposal vessel. Add solidification agents and compress container for long term storage.
Date: March 6, 1991
Creator: Forsberg, C. W.
System: The UNT Digital Library
Process for producing clad superconductive materials (open access)

Process for producing clad superconductive materials

A process for fabricating superconducting composite wire by the steps of placing a superconductive precursor admixture capable of undergoing a self propagating combustion in stoichiometric amounts sufficient to form a superconductive product within a metal tube, sealing one end of said tube, igniting said superconductive precursor admixture whereby said superconductive precursor admixture endburns along the length of the admixture, and cross-section reducing said tube at a rate substantially equal to the rate of burning of said superconductive precursor admixture and at a point substantially planar with the burnfront of the superconductive precursor mixture, whereby a clad superconductive product is formed in situ, the product characterized as superconductive without a subsequent sintering stage, is disclosed.
Date: March 19, 1991
Creator: Cass, R. B.; Ott, K. C. & Peterson, D. E.
System: The UNT Digital Library