Graph-theoretic algorithm for hierarchial decomposition of dynamic systems (open access)

Graph-theoretic algorithm for hierarchial decomposition of dynamic systems

A graph-theoretic scheme is proposed for partitioning of dynamic systems into hierarchially ordered subsystems having independent inputs and outputs. The resulting subsystems are input-output reachable as well as structurally controllable and observable, so that a piece-by-piece design of estimators and controllers can be accomplished for systems with large dimensions without excessive computer requirements.
Date: March 24, 1982
Creator: Pichai, V.; Sezer, M.E. & Siljak, D.D.
Object Type: Report
System: The UNT Digital Library
Improved radioimmunotherapy of hematologic malignancies (open access)

Improved radioimmunotherapy of hematologic malignancies

This research project proposes to develop novel new approaches of improving the radioimmunodetection and radioimmunotherapy of malignancies by augmenting retention of radioimmunoconjugates by tumor cells. The approaches shown to be effective in these laboratory experiments will subsequently be incorporated into out ongoing clinical trials in patients. Specific project objectives include: to study the rates of endocytosis, intracellular routing, and metabolic degradation of radiolabeled monoclonal antibodies targeting tumor-associated antigens on human leukemia and lymphoma cells; To examine the effects of lysosomotropic amines (e.g. chloroquine, amantadine), carboxylic ionophores (monensin, nigericin), and thioamides (propylthiouracil), on the retention of radiolabeled MoAbs by tumor cells; to examine the impact of newer radioiodination techniques (tyramine cellobiose, paraiodobenzoyl) on the metabolic degradation of radioiodinated antibodies; to compare the endocytosis, intracellular routing, and degradation of radioimmunoconjugates prepared with different radionuclides ({sup 131}Iodine, {sup 111}Indium, {sup 90}Yttrium, {sup 99m}Technetium, {sup 186}Rhenium); and to examine the utility of radioimmunoconjugates targeting oncogene products for the radioimmunotherapy and radioimmunoscintigraphy of cancer.
Date: March 24, 1992
Creator: Press, O.W.
Object Type: Report
System: The UNT Digital Library
Transistorized power switch and base drive circuit therefore (open access)

Transistorized power switch and base drive circuit therefore

A high power switching circuit is disclosed which utilizes a four-terminal Darlington transistor block to improve switching speed, particularly in rapid turn-off. Two independent reverse drive currents are utilized during turn-off in order to expel the minority carriers of the Darlington pair at their own charge sweep-out rate. The reverse drive current may be provided by a current transformer, the secondary of which is tapped to the base terminal of the power stage of the Darlington block. In one application, the switching circuit is used in each power switching element in a chopper-inverter drive of an electric vehicle propulsion system.
Date: March 24, 1981
Creator: Lee, F.C. & Carter, R.A.
Object Type: Patent
System: The UNT Digital Library
Measurement of the tau- to eta pi-pi+pi-nu tau Branching Fraction and a Search for a Second-Class Current in the tau- to eta'(958)pi-nu tau Decay (open access)

Measurement of the tau- to eta pi-pi+pi-nu tau Branching Fraction and a Search for a Second-Class Current in the tau- to eta'(958)pi-nu tau Decay

The {tau}{sup -} {yields} {eta}{pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}} decay with the {eta} {yields} {gamma}{gamma} mode is studied using 384 fb{sup -1} of data collected by the BABAR detector. The branching fraction is measured to be (1.60 {+-} 0.05 {+-} 0.11) x 10{sup -4}. It is found that {tau}{sup -} {yields} f{sub 1}(1285){pi}{sup -} {nu}{sub {tau}} {yields} {eta}{pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}} is the dominant decay mode with a branching fraction of (1.11 {+-} 0.06 {+-} 0.05) x 10{sup -4}. The first error on the branching fractions is statistical and the second systematic. In addition, a 90% confidence level upper limit on the branching fraction of the {tau}{sup -} {yields} {eta}{prime}(958){pi}{sup -}{nu}{sub {tau}} decay is measured to be 7.2 x 10{sup -6}. This last decay proceeds through a second-class current and is expected to be forbidden in the limit of isospin symmetry.
Date: March 24, 2008
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V. et al.
Object Type: Article
System: The UNT Digital Library
Analyses of Oxyanion Materials by Prompt Gamma Activation Analysis (open access)

Analyses of Oxyanion Materials by Prompt Gamma Activation Analysis

Prompt gamma activation analysis (PGAA) has been used to analyze metal ion oxyanion materials that have multiple applications, including medicine, materials, catalysts, and electronics. The significance for the need for accurate, highly sensitive analyses for the materials is discussed in the context of quality control of end products containing the parent element in each material. Applications of the analytical data for input to models and theoretical calculations related to the electronic and other properties of the materials are discussed.
Date: March 24, 2008
Creator: Firestone, Richard B.; Perry, D. L.; English, G. A.; Firestone, R. B.; Leung, K. N.; Garabedian, G. et al.
Object Type: Article
System: The UNT Digital Library
Development of a Multi Megawatt Circulator for X Band (open access)

Development of a Multi Megawatt Circulator for X Band

Research is in progress on a TeV-scale linear collider that will operate at 5-10 times the energy of present-generation accelerators. This will require development of high power RF sources generating of 50-100 MW per source. Transmission of power at this level requires overmoded waveguide to avoid breakdown. In particular, the TE{sub 01} circular waveguide mode is currently the mode of choice for waveguide transmission at Stanford Linear Accelerator Center (SLAC) in the Multimode Delay Line Distribution System (MDLDS). A common device for protecting an RF source from reflected power is the waveguide circulator. A circulator is typically a three-port device that allows low loss power transmission from the source to the load, but diverts power coming from the load (reflected power) to a third terminated port. To achieve a low loss, matched, three port junction requires nonreciprocal behavior. This is achieved using ferrites in a static magnetic field which introduces a propagation constant dependent on RF field direction relative to the static magnetic field. Circulators are currently available at X-Band for power levels up to 1 MW in fundamental rectangular waveguide; however, the next generation of RF sources for TeV-level accelerators will require circulators in the 50-100 MW range. Clearly, …
Date: March 24, 2008
Creator: Neilson, J.; Ives, L. & Tantawi, S. G.
Object Type: Article
System: The UNT Digital Library
Quantitative comparison between Type Ia supernova spectra at low and high redshifts: A case study (open access)

Quantitative comparison between Type Ia supernova spectra at low and high redshifts: A case study

We develop a method to measure the strength of the absorption features in type Ia supernova (SN Ia) spectra and use it to make a quantitative comparisons between the spectra of type Ia supernovae at low and high redshifts. In this case study, we apply the method to 12 high-redshift (0.212 = z = 0.912) SNe Ia observed by the Supernova Cosmology Project. Through measurements of the strengths of these features and of the blueshift of theabsorption minimum in Ca ii H&K, we show that the spectra of the high-redshift SNe Ia are quantitatively similar to spectra of nearby SNe Ia (z< 0.15). One supernova in our high redshift sample, SN 2002fd at z = 0.279, is found to have spectral characteristics that are associated with peculiar SN 1991T/SN 1999aa-like supernovae.
Date: March 24, 2008
Creator: Supernova Cosmology Project
Object Type: Article
System: The UNT Digital Library
Sonoma Persistent Surveillance System (open access)

Sonoma Persistent Surveillance System

Sonoma offers the first cost-effective, broad-area, high-resolution, real-time motion imagery system for surveillance applications. Sonoma is unique in its ability to provide continuous, real-time video imagery of an area the size of a small city with resolutions sufficient to track 8,000 moving objects in the field of view. At higher resolutions and over smaller areas, Sonoma can even track the movement of individual people. The visual impact of the data available from Sonoma is already causing a paradigm shift in the architecture and operation of other surveillance systems. Sonoma is expected to cost just one-tenth the price of comparably sized sensor systems. Cameras mounted on an airborne platform constantly monitor an area, feeding data to the ground for real-time analysis. Sonoma was designed to provide real-time data for actionable intelligence in situations such as monitoring traffic, special events, border security, and harbors. If a Sonoma system had been available in the aftermath of the Katrina and Rita hurricanes, emergency responders would have had real-time information on roads, water levels, and traffic conditions, perhaps saving many lives.
Date: March 24, 2006
Creator: Pennington, D M
Object Type: Report
System: The UNT Digital Library
An Integrated Assessment of Geochemical and Community Structure Determinants of Metal Reduction Rates in Subsurface Sediments (open access)

An Integrated Assessment of Geochemical and Community Structure Determinants of Metal Reduction Rates in Subsurface Sediments

This project represented a joint effort between Oak Ridge National Laboratory (ORNL), the University of Tennessee (UT), and Florida State University (FSU). ORNL served as the lead in-stitution with Dr. A.V. Palumbo responsible for project coordination, integration, and deliver-ables. In situ uranium bioremediation is focused on biostimulating indigenous microorganisms through a combination of pH neutralization and the addition of large amounts of electron donor. Successful biostimulation of U(VI) reduction has been demonstrated in the field and in the laboratory. However, little data is available on the dynamics of microbial populations capable of U(VI) reduction, and the differences in the microbial community dynamics between proposed electron donors have not been explored. In order to elucidate the potential mechanisms of U(VI) reduction for optimization of bioremediation strategies, structure-function relationships of microbial populations were investigated in microcosms of subsurface materials cocontaminated with radionuclides and nitrate from the Oak Ridge Field Research Center (ORFRC), Oak Ridge, Tennessee.
Date: March 24, 2008
Creator: Kostka, Joel E.
Object Type: Report
System: The UNT Digital Library
Actinic EUV mask inspection beyond 0.25 NA (open access)

Actinic EUV mask inspection beyond 0.25 NA

The SEMATECH Berkeley Actinic Inspection Tool (AIT) is an EUV-wavelength mask inspection microscope designed for direct aerial image measurements, and pre-commercial EUV mask research. Operating on a synchrotron bending magnet beamline, the AIT uses an off-axis Fresnel zoneplate lens to project a high-magnification EUV image directly onto a CCD camera. We present the results of recent system upgrades that have improved the imaging resolution, illumination uniformity, and partial coherence. Benchmarking tests show image contrast above 75% for 100-nm mask features, and significant improvements and across the full range of measured sizes. The zoneplate lens has been replaced by an array of user-selectable zoneplates with higher magnification and NA values up to 0.0875, emulating the spatial resolution of a 0.35-NA 4x EUV stepper. Illumination uniformity is above 90% for mask areas 2-{micro}m-wide and smaller. An angle-scanning mirror reduces the high coherence of the synchrotron beamline light source giving measured {sigma} values of approximately 0.125 at 0.0875 NA.
Date: March 24, 2008
Creator: Goldberg, Kenneth A.; Mochi, Iacopo; Anderson, Erik H.; Rekawa, Seno. B.; Kemp, Charles D.; Huh, S. et al.
Object Type: Article
System: The UNT Digital Library
Coupling Multi-Component Models with MPH on Distributed Memory Computer Architectures (open access)

Coupling Multi-Component Models with MPH on Distributed Memory Computer Architectures

A growing trend in developing large and complex applications on today's Teraflop scale computers is to integrate stand-alone and/or semi-independent program components into a comprehensive simulation package. One example is the Community Climate System Model which consists of atmosphere, ocean, land-surface and sea-ice components. Each component is semi-independent and has been developed at a different institution. We study how this multi-component, multi-executable application can run effectively on distributed memory architectures. For the first time, we clearly identify five effective execution modes and develop the MPH library to support application development utilizing these modes. MPH performs component-name registration, resource allocation and initial component handshaking in a flexible way.
Date: March 24, 2005
Creator: He, Yun & Ding, Chris
Object Type: Article
System: The UNT Digital Library
NUCLEAR WASTE GLASSES CONTINUOUS MELTING AND BULK VITRIFICAITON (open access)

NUCLEAR WASTE GLASSES CONTINUOUS MELTING AND BULK VITRIFICAITON

This contribution addresses various aspects of nuclear waste vitrification. Nuclear wastes have a variety of components and composition ranges. For each waste composition, the glass must be formulated to possess acceptable processing and product behavior defined in terms of physical and chemical properties that guarantee the glass can be easily made and resist environmental degradation. Glass formulation is facilitated by developing property-composition models, and the strategy of model development and application is reviewed. However, the large variability of waste compositions presents numerous additional challenges: insoluble solids and molten salts may segregate; foam may hinder heat transfer and slow down the process; molten salts may accumulate in container refractory walls; the glass on cooling may precipitate crystalline phases. These problems need targeted exploratory research. Examples of specific problems and their possible solutions are discussed.
Date: March 24, 2008
Creator: AA, KRUGER & PR, HRMA
Object Type: Article
System: The UNT Digital Library
Design and Test of a 100MW X Band TE01 Window (open access)

Design and Test of a 100MW X Band TE01 Window

Research at Stanford Linear Accelerator Center (SLAC) is in progress on a TeV-scale linear collider that will operate at 5-10 times the energy of present generation accelerators. This will require development of high power X-Band sources generating 50-100 MW per source. Conventional pillbox window designs are capable of transmitting peak rf powers up to about 30 MW, well below the desired level required for the use of a single window per tube. SLAC has developed a 75 MW TE{sub 01} window [1] that uses a 'traveling wave' design to minimize fields at the window face. Irises match to the dielectric window impedance, resulting in a pure traveling wave in the ceramic and minimum fields on the window face. The use of the TE{sub 01} mode also has zero electric field on the braze fillet. Unfortunately, in-band resonances prevented this window design from achieving the desired 75MW power level. It was believed the resonances resulted from sudden steps in the circular guide to match the 38mm input diameter to the overmoded (TE{sub 01} and TE{sub 02} mode propagating) 65 mm diameter of the window ceramic. Calabazas Creek Research Inc. is currently developing a traveling wave window using compact, numerically optimized, parabolic …
Date: March 24, 2008
Creator: Neilson, J.; Ives, L. & Tantawi, S. G.
Object Type: Article
System: The UNT Digital Library
Elevated Uptake of Th and U by Netted Chain Fern (Woodwardia areloata) (open access)

Elevated Uptake of Th and U by Netted Chain Fern (Woodwardia areloata)

None
Date: March 24, 2006
Creator: KNOX, ANNA
Object Type: Article
System: The UNT Digital Library
Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas (open access)

Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas

Supermassive black holes (SMBHs) are a ubiquitous component of the nuclei of galaxies. It is normally assumed that, following the merger of two massive galaxies, a SMBH binary will form, shrink due to stellar or gas dynamical processes and ultimately coalesce by emitting a burst of gravitational waves. However, so far it has not been possible to show how two SMBHs bind during a galaxy merger with gas due to the difficulty of modeling a wide range of spatial scales. Here we report hydrodynamical simulations that track the formation of a SMBH binary down to scales of a few light years following the collision between two spiral galaxies. A massive, turbulent nuclear gaseous disk arises as a result of the galaxy merger. The black holes form an eccentric binary in the disk in less than a million years as a result of the gravitational drag from the gas rather than from the stars.
Date: March 24, 2008
Creator: Mayer, L.; Kazantzidis, S.; Madau, P.; Colpi, M.; Quinn, T. & Wadsley, J.
Object Type: Article
System: The UNT Digital Library
400 MeV upgrade for the Fermilab linac (open access)

400 MeV upgrade for the Fermilab linac

Fermilab has plans for a comprehensive accelerator upgrade to open new possibilities for both the fixed target and collider experimental programs. An early step in this program is to increase the energy of the linac from 200 to 400 MeV by replacing the last four of its nine 201 MHz Alvarez tanks with twenty-eight 805 MHz side-coupled cavity chains operating at about 8 MV/m average axial field. The principal purpose is to reduce the incoherent spacecharge tuneshift at injection into the Booster which currently limits both the brightness of the beam, an important determinant of collider luminosity, and total intensity to produce both the antiprotons for the collider and the beams to fixed target experimental areas. Other consequences of higher Booster injection energy expected to contribute to some degree of higher intensity limits and improved operational characteristics include improved quality of the guide field at injection, reduced frequency swing for the rf systems, and smaller emittance for the injected beam. The linac upgrade project has moved from a 1986 study through a development project including structure models and numerical studies to a full-feature module prototyping starting this year.
Date: March 24, 1989
Creator: MacLachlan, J.A.
Object Type: Article
System: The UNT Digital Library
Surface studies of UFe2 and evaluation of its catalytic properties with a 2H2:CO mixture (open access)

Surface studies of UFe2 and evaluation of its catalytic properties with a 2H2:CO mixture

The reactivity of UFe2 with O2, CO and CO2 were studied using x-ray photoelectron spectroscopy (XPS). Adsorption of O2 on clean UFe2 surfaces (Fe/U approx. = 2.0), produced by argon-ion sputtering, leads to the formation of UO2 and depletion of Fe from the surface layer probed by XPS (Fe/U approx. = 0.8). The oxidation state of Fe in this layer, as determined by XPS (Fe 2p/sub 3/2/ = 710.4 eV), is between Fe S and Fe T of pure Fe oxides. Exposure of sputtered-clean UFe2 to CO and CO2 results in a slight broadening of the U 4f peaks, indicating U oxidation, and some Fe depletion in the analyzed layer (Fe/U approx. = 1.7). The O ls (530.2 and 530.4 eV for CO and CO2, respectively) and C ls (282.7 and 282.6 eV for CO and CO2, respectively) indicate that dissociative chemisorption to O and C atoms occurs. UFe2 ground into a fine powder was tested as a catalyst in a differential high-pressure flow reactor with a 2H2:CO gas mixture. A significant amount of methanol and hydrocarbons are produced at 577K; while hydrocarbons are the main products (>99%) at 739K. XPS analysis of the used catalyst indicates that U is …
Date: March 24, 1987
Creator: Schultz, J.; Naegele, J.; Spirlet, J.C. & Colmenares, C.
Object Type: Article
System: The UNT Digital Library
Method and apparatus for the formation of a spheromak plasma (open access)

Method and apparatus for the formation of a spheromak plasma

An inductive method and apparatus for forming detached spheromak plasma using a thin-walled metal toroidal ring are described that uses external current leads and internal poloidal and toroidal field coils located inside a vacuum chamber filled with low density hydrogen gas and an external axial field generating coil. The presence of a current in the poloidal field coils, and an externally generated axial field sets up the initial poloidal field configuration in which the field is strongest toward the major axis of the toroid. The internal toroidal-field-generating coil is then pulsed on, ionizing the gas and inducing poloidal current and toroidal magnetic field into the plasma region in the sleeve exterior to and adjacent to the ring and causing the plasma to expand away from the ring and toward the major axis. Next the current in the poloidal field coils in the ring is reversed. This induces toroidal current into the plasma and causes the poloidal magnetic field lines to reconnect. The reconnection continues until substantially all of the plasma is formed in a separated spheromak configuration held in equilibrium by the initial external field.
Date: March 24, 1981
Creator: Jardin, S. C.; Yamada, M.; Furth, H. P. & Okabayashi, M.
Object Type: Patent
System: The UNT Digital Library
Role of the Materials Review Board and the nuclear waste materials handbook (open access)

Role of the Materials Review Board and the nuclear waste materials handbook

The US Department of Energy has established an organizational structure that assures the quality of key data identified as being important to the licensing of a nuclear waste repository by the US Nuclear Regulatory Commission. The Materials Characterization Center collects and/or develops the test methods needed to obtain the data, and acts as a clearinghouse for all data obtained by the methods, regardless of source. The Materials Review Board reviews both test methods and test data submitted to it, and approves them if they meet the rigorous criteria and standards that have been established. The appearance of test methods and test data in the Nuclear Waste Materials Handbook is evidence that the material has undergone intensive review and can be used with confidence within the bounds of the application specified. The principal use of the Handbook is in the repository licensing process.
Date: March 24, 1985
Creator: Steindler, M.J. & Seefeldt, W.B.
Object Type: Article
System: The UNT Digital Library
A structural evaluation of the Shippingport reactor pressure vessel for transport impact conditions (open access)

A structural evaluation of the Shippingport reactor pressure vessel for transport impact conditions

The Shippingport Atomic Power Station in Shippingport, Pennsylvania, is being decommissioned and dismantled. This government-leased property will be returned, in a radiologically safe condition, to its owner. All radioactive material is being removed from the Shippingport Station and transported for burial to the DOE Hanford Reservation in Richland, Washington. The reactor pressure vessel (RPV) will be transported by barge to Hanford. This paper describes an evaluation of the structural response of the RPV to the normal and accident impact test conditions as required by the Code of Federal Regulations. 3 refs., 5 figs., 3 tabs.
Date: March 24, 1989
Creator: Witte, M.C. & Chou, C.K.
Object Type: Article
System: The UNT Digital Library
Processing of geothermal brine effluents for injection (open access)

Processing of geothermal brine effluents for injection

The handling and disposal of brine effluents is a critical part of any geothermal conversion process. Brine effluents from the San Diego Gas and Electric/Department of Energy--Geothermal Loop Experimental Facility were characterized for particulate concentration and chemical composition. Bench scale tests were conducted with inorganic and organic coagulants as a means of enhancing the sedimentation process for separation and removal of suspended solids, principally amorphous silica. The effects of temperature, retention time, and pH on the precipitation of supersaturated silica, subsequent floc settling properties, and supernatant clarity were also determined. A design of a pilot scale clarifier now undergoing testing is also described.
Date: March 24, 1978
Creator: Quong, R.; Schoepflin, F. & Stout, N.D.
Object Type: Article
System: The UNT Digital Library
Relationships between removal processes and residence times for atmospheric pollutants (open access)

Relationships between removal processes and residence times for atmospheric pollutants

This report is concerned with improving estimates for the residence times of atmospheric trace constituents in various atmospheric reservoirs. Residence times are defined only for steady-state conditions; i.e., when the net growth rate vanishes. The most useful case of vanishing net growth rate is when the total growth rate is equal to the decay rate. It is demonstrated that the most important advance towards improving estimates of pollutant residence times is through proper choices of reservoirs. Chosen reservoirs should possess the following features: steady-state conditions, uniform mixing ratio throughout or throughout specified subreservoirs, and subreservoirs chosen in which removal rates can be treated as approximate constants. An example of a poorly mixed reservoir, the stratosphere, is discussed. In another example, it is suggested that commonly used reservoirs for atmospheric CO/sub 2/ have been chosen poorly and that a substantial portion of the anthropogenic CO/sub 2/ released during the past 50 years may still be mixing into the stratosphere. In another example, it is suggested that determination of the dry deposition velocity for accumulation-mode aerosol particles may not be so important as previously thought. To improve estimates for the atmospheric residence times of these particles, it is important to increase knowledge …
Date: March 24, 1978
Creator: Slinn, W.G.N.
Object Type: Article
System: The UNT Digital Library
Photovoltaic module design, qualification, and testing specification. Low-Cost Solar Array Project (open access)

Photovoltaic module design, qualification, and testing specification. Low-Cost Solar Array Project

This specification establishes minimum design, qualification and acceptance requirements for terrestrial solar cell modules suitable for incorporation in photovoltaic array applications in the 20kW to 500kW range, such as defined by Department of Energy PRDA EM-D-04-0038. Both mandatory and recommended requirement levels for selected performance criteria have been specified for modules within these arrays. As applicable, the manufacturer/contractor shall be responsible for generation and selection of appropriate design or test levels within the scope of these criteria. Specification of any additional requirements as necessary to satisfy the particular array or system application shall be the responsibility of the manufacturer/contractor. Environmental requirements imposed by this specification are considered to be the minimum level acceptable to DOE. Test procedures are detailed.
Date: March 24, 1978
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Beam test of a large area silicon drift detector (open access)

Beam test of a large area silicon drift detector

The results from the tests of the first large area (4 [times] 4 cm[sup 2]) planar silicon drift detector prototype in a pion beam are reported. The measured position resolution in the drift direction is ([sigma]=40 [plus minus] 10)[mu]m.
Date: March 24, 1992
Creator: Castoldi, A.; Chinnici, S.; Gatti, E.; Longoni, A.; Palma, F.; Sampietro, M. (Consiglio Nazionale delle Ricerche, Milan (Italy)) et al.
Object Type: Article
System: The UNT Digital Library