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Fermi Large Area Telescope Observations of the Active Galaxy 4C 55.17: Steady, Hard Gamma-Ray Emission and its Implications (open access)

Fermi Large Area Telescope Observations of the Active Galaxy 4C 55.17: Steady, Hard Gamma-Ray Emission and its Implications

None
Date: April 22, 2013
Creator: McConville, W.; Ostorero, L.; Moderski, R.; Stawarz, L.; Cheung, C. C.; Ajello, M. et al.
Object Type: Article
System: The UNT Digital Library
Development of a Generalized Methodology for Soil-Structure Interaction Analysis Using Nonlinear Time-Domain TechniquesNEAMS Program, DOE Office of Nuclear Energy (NE-41) (open access)

Development of a Generalized Methodology for Soil-Structure Interaction Analysis Using Nonlinear Time-Domain TechniquesNEAMS Program, DOE Office of Nuclear Energy (NE-41)

None
Date: April 22, 2013
Creator: Solberg, J. M.; Hossain, Q.; Blink, J. A.; Bohlen, S. R.; Mseis, G. & Greenberg, H.
Object Type: Report
System: The UNT Digital Library
Micro-Anatomy Imager (open access)

Micro-Anatomy Imager

None
Date: April 22, 2013
Creator: Demos, S G
Object Type: Report
System: The UNT Digital Library
Technical Letter Report Development of Flaw Size Distribution Tables Including Effects of Flaw Depth Sizing Errors for Draft 10CFR 50.61a (Alternate PTS Rule) JCN-N6398, Task 4 (open access)

Technical Letter Report Development of Flaw Size Distribution Tables Including Effects of Flaw Depth Sizing Errors for Draft 10CFR 50.61a (Alternate PTS Rule) JCN-N6398, Task 4

This document describes a new method to determine whether the flaws in a particular reactor pressure vessel are consistent with the assumptions regarding the number and sizes of flaws used in the analyses that formed the technical justification basis for the new voluntary alternative Pressurized Thermal Shock (PTS) rule (Draft 10 CFR 50.61a). The new methodology addresses concerns regarding prior methodology because ASME Code Section XI examinations do not detect all fabrication flaws, they have higher detection performance for some flaw types, and there are flaw sizing errors always present (e.g., significant oversizing of small flaws and systematic under sizing of larger flaws). The new methodology allows direct comparison of ASME Code Section XI examination results with values in the PTS draft rule Tables 2 and 3 in order to determine if the number and sizes of flaws detected by an ASME Code Section XI examination are consistent with those assumed in the probabilistic fracture mechanics calculations performed in support of the development of 10 CFR 50.61a.
Date: April 22, 2013
Creator: Simonen, Fredric A.; Gosselin, Stephen R. & Doctor, Steven R.
Object Type: Report
System: The UNT Digital Library
Trace Assessment for BWR ATWS Analysis (open access)

Trace Assessment for BWR ATWS Analysis

A TRACE/PARCS input model has been developed in order to be able to analyze anticipated transients without scram (ATWS) in a boiling water reactor. The model is based on one developed previously for the Browns Ferry reactor for doing loss-of-coolant accident analysis. This model was updated by adding the control systems needed for ATWS and a core model using PARCS. The control systems were based on models previously developed for the TRAC-B code. The PARCS model is based on information (e.g., exposure and moderator density (void) history distributions) obtained from General Electric Hitachi and cross sections for GE14 fuel obtained from an independent source. The model is able to calculate an ATWS, initiated by the closure of main steam isolation valves, with recirculation pump trip, water level control, injection of borated water from the standby liquid control system and actuation of the automatic depres-surization system. The model is not considered complete and recommendations are made on how it should be improved.
Date: April 22, 2010
Creator: Cheng, L. Y.; Diamond, D. & Arantxa Cuadra, Gilad Raitses, Arnold Aronson
Object Type: Report
System: The UNT Digital Library
MEASUREMENTS OF PAST 14C LEVELS AND 13C/12C RATIOS IN THE SURFACE WATERS OF THE WORLD'S SUBPOLAR OCEANS. (open access)

MEASUREMENTS OF PAST 14C LEVELS AND 13C/12C RATIOS IN THE SURFACE WATERS OF THE WORLD'S SUBPOLAR OCEANS.

Under this project we have developed methods that allow the reconstruction of past {sup 14}C levels of the surface waters of the subpolar North Pacific Ocean by measuring the {sup 14}C contents of archived salmon scales. The overall goal of this research was to reduce of the uncertainty in the uptake of fossil CO{sub 2} by the oceans and thereby improve the quantification of the global carbon cycle and to elucidate the fate of anthropogenic CO{sub 2}. Ocean General Circulation Models (OGCMs), with their three dimensional global spatial coverage and temporal modeling capabilities, provide the best route to accurately calculating the total uptake of CO{sub 2} by the oceans and, hence, to achieving the desired reduction in uncertainty. {sup 14}C has played, and continues to play, a central role in the validation of the OGCMs calculations, particularly with respect to those model components which govern the uptake of CO{sub 2} from the atmosphere and the transport of this carbon within the oceans. Under this project, we have developed time-series records of the {sup 14}C levels of the surface waters of three areas of the subpolar North Pacific Ocean. As the previously available data on the time-history of oceanic surface water …
Date: April 22, 2010
Creator: Brown, T A
Object Type: Report
System: The UNT Digital Library
The Influence of Linker Geometry on Uranyl Complexation by Rigidly-Linked Bis(3-hydroxy-N-methyl-pyridin-2-one) (open access)

The Influence of Linker Geometry on Uranyl Complexation by Rigidly-Linked Bis(3-hydroxy-N-methyl-pyridin-2-one)

A series of bis(3-hydroxy-N-methyl-pyridin-2-one) ligands was synthesized, and their respective uranyl complexes were characterized by single crystal X-ray diffraction analyses. These structures were inspected for high-energy conformations and evaluated using a series of metrics to measure co-planarity of chelating moieties with each other and the uranyl coordination plane, as well as to measure coordinative crowding about the uranyl dication. Both very short (ethyl, 3,4-thiophene and o-phenylene) and very long ({alpha},{alpha}{prime}-m-xylene and 1,8-fluorene) linkers provide optimal ligand geometries about the uranyl cation, resulting in planar, unstrained molecular arrangements. The planarity of the rigid linkers also suggests there is a degree of pre-organization for a planar coordination mode that is ideal for uranyl-selective ligand design. Comparison of intramolecular N{sub amide}-O{sub phenolate} distances and {sup 1}H NMR chemical shifts of amide protons supports earlier results that short linkers provide the optimal geometry for intramolecular hydrogen bonding.
Date: April 22, 2010
Creator: Szigethy, Geza & Raymond, Kenneth
Object Type: Article
System: The UNT Digital Library
Epithermal Neutron Source for Neutron Resonance Spectroscopy (NRS) using High Intensity, Short Pulse Lasers (open access)

Epithermal Neutron Source for Neutron Resonance Spectroscopy (NRS) using High Intensity, Short Pulse Lasers

A neutron source for neutron resonance spectroscopy (NRS) has been developed using high intensity, short pulse lasers. This measurement technique will allow for robust measurements of interior ion temperature of laser-shocked materials and provide insight into equation of state (EOS) measurements. The neutron generation technique uses protons accelerated by lasers off of Cu foils to create neutrons in LiF, through (p,n) reactions with {sup 7}Li and {sup 19}F. The distribution of the incident proton beam has been diagnosed using radiochromic film (RCF). This distribution is used as the input for a (p,n) neturon prediction code which is compared to experimentally measured neutron yields. From this calculation, a total fluence of 1.8 x 10{sup 9} neutrons is infered, which is shown to be a reasonable amount for NRS temperature measurement.
Date: April 22, 2010
Creator: Higginson, D. P.; McNaney, J. M.; Swift, D. C.; Bartal, T.; Hey, D. S.; Pape, S. L. et al.
Object Type: Article
System: The UNT Digital Library
Design of a 2 Slot VLPC Cryostat Cooled by a Cryocooler (open access)

Design of a 2 Slot VLPC Cryostat Cooled by a Cryocooler

The conceptual design and preliminary engineering calculations have been completed for a two cassette cryostat. This report summarizes the design. A cryocooler is permanently mounted in the center of a stainless steel, 0.75 inch thick top lid. The cryocooler sits upon a spacer which raises the cooling stage elevations to favorably match the cassette heat intercept elevations. The top lid (32.0-inch outside diameter) mates to a 24-inch pipe size flange with o-ring. The 24-inch pipe size vacuum vessel with end plate has a minimum internal depth of 16-inch to give adequate clearance for the depth of the cryocooler and multilayer insulation blankets. Support stand legs elevate the container to a convenient height and allow for placement of the AFE power supply underneath. Two cassette slots are located on either side of the cryocooler. The slots are positioned parallel to each other, 10.5-inch center to center (6 standard cassette slot widths) so that the standard 8 slot AFE backplane can be used. The slot opening through the lid is approximately 1.422-inch x 16.782-inch. A 0.016-inch thick titanium (Ti-6AI-4V) envelope with sealing lip is inserted through lid and defines the gas helium boundary that the VLPC cassette resides. The internal dimensions of …
Date: April 22, 2004
Creator: Rucinski, Russell A.
Object Type: Report
System: The UNT Digital Library
DOD-SBIR Structured Multi-Resolution PIC Code for Electromagnetic Plasma Simulations, Final Report (open access)

DOD-SBIR Structured Multi-Resolution PIC Code for Electromagnetic Plasma Simulations, Final Report

A novel electromagnetic solver with mesh refinement capability was implemented in Warp. The solver allows for calculations in 2-1/2 and 3 dimensions, includes the standard Yee stencil, and the Cole-Karkkainen stencil for lower numerical dispersion along the principal axes. Warp implementation of the Cole-Karkkainen stencil includes an extension to perfectly matched layers (PML) for absorption of waves, and is preserving the conservation property of charge conserving current deposition schemes, like the Buneman-Villanesor and Esirkepov methods. Warp's mesh refinement framework (originally developed for electrostatic calculations) was augmented to allow for electromagnetic capability, following the methodology presented in [1] extended to an arbitrary number of refinement levels. Other developments include a generalized particle injection method, internal conductors using stair-cased approximation, and subcycling of particle pushing. The solver runs in parallel using MPI message passing, with a choice at runtime of 1D, 2D and 3D domain decomposition, and is shown to scale linearly on a test problem up-to 32,768 CPUs. The novel solver was tested on the modeling of filamentation instability, fast ignition, ion beam induced plasma wake, and laser plasma acceleration.
Date: April 22, 2010
Creator: Vay, J. L.; Grote, D. P. & Friedman, A.
Object Type: Report
System: The UNT Digital Library
Aluminum-Catalyzed Intramolecular Hydroamination of Aminoalkenes (open access)

Aluminum-Catalyzed Intramolecular Hydroamination of Aminoalkenes

A new aluminium complex bearing a dianionic phenylene-diamine based ligand has been synthesized and shown to catalyze the intramolecular hydroamination of various aminoalkenes.
Date: April 22, 2010
Creator: Koller, Juergen & Bergman, Robert
Object Type: Article
System: The UNT Digital Library
Instability Control in a Staged Z-pinch (open access)

Instability Control in a Staged Z-pinch

A \Staged Z-Pinch” is a fusion-energy concept in which stored-electric energy is first converted into plasma-liner-kinetic energy, and then transferred to a coaxialtarget plasma [H. U. Rahman, F. J. Wessel, and N. Rostoker, Phys. Rev. Lett. 74, p. 714(1996)]. Proper choice of the liner and target materials, and their initial radii and mass densities, leads to dynamic stabilization, current amplification, and shock heating of the target. Simulations suggest that this configuration has merit as a alternative inertial-confinement-fusion concept, and may provide an energy release exceeding thermonuclear break-even, if tested on one of many newer pulsed power systems, for example those located at Sandia National Laboratories.
Date: April 22, 2011
Creator: WESSEL, Frank J.
Object Type: Report
System: The UNT Digital Library
Advanced Simulation and Computing Fiscal Year 2011-2012 Implementation Plan, Revision 0 (open access)

Advanced Simulation and Computing Fiscal Year 2011-2012 Implementation Plan, Revision 0

The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering (D&E) programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is …
Date: April 22, 2010
Creator: McCoy, M.; Phillips, J.; Hpson, J. & Meisner, R.
Object Type: Report
System: The UNT Digital Library
Construction and Calibration of the Scanning and Measuring Projector (open access)

Construction and Calibration of the Scanning and Measuring Projector

None
Date: April 22, 1964
Creator: Davey, P. G. & Schwemin, A. J.
Object Type: Report
System: The UNT Digital Library
On the Possible Use of the CERN 200-MHz Cavities for the RHIC Beam Storage System (open access)

On the Possible Use of the CERN 200-MHz Cavities for the RHIC Beam Storage System

None
Date: April 22, 1991
Creator: R., McKenzie-Wilson & Pirkl, W.
Object Type: Report
System: The UNT Digital Library
RHIC Injection and Beam Dump Schemes (open access)

RHIC Injection and Beam Dump Schemes

None
Date: April 22, 1987
Creator: J., Claus
Object Type: Report
System: The UNT Digital Library
Grant No DE-FG02-03ER83720 Report for US Department of Engery (open access)

Grant No DE-FG02-03ER83720 Report for US Department of Engery

Effective and reliable nuclear monitoring requires discrimination between small magnitude explosions and earthquakes based on the use of limited regional data. Lg is generally the largest seismic phase from both explosion and earthquake sources recorded at regional distances. For small events, Lg may sometimes be the only well-recorded seismic phase so that discriminants based only on the use of Lg are especially desirable. Recent research has provided significantly better understanding of Lg by demonstrating that the explosion-generated Rg makes significant contribution to the low-frequency S or Lg from explosions. Near-source scattering of explosion-generated Rg appears to be a viable mechanism for generating low-frequency(< 2 Hz) Lg waves from explosions. Detailed knowledge of the complex scattering process is, however, still incomplete and is in fact the subject of several ongoing studies. Our analysis of regional data from nuclear explosions from both Nevada Test Site (NTS) and Kazakh Test Site (KTS) and nearby earthquakes in Phase I has suggested that there are several reliable source discrimination methods only based on the use of Lg at regional distances. These discriminants should be. especially useful for small magnitude seismic events for which Lg may be the only well-recorded seismic phase. Our results suggest four …
Date: April 22, 2004
Creator: Chan, Winston & Wagner, Robert
Object Type: Report
System: The UNT Digital Library
Observation of high soft x-ray drive in large-scale hohlraums at the National Ignition Facility (open access)

Observation of high soft x-ray drive in large-scale hohlraums at the National Ignition Facility

None
Date: April 22, 2010
Creator: Kline, J. L.; Glenzer, S. H.; Olson, R. E.; Suter, L. J.; Widmann, K.; Callahan, D. A. et al.
Object Type: Article
System: The UNT Digital Library
Near-ultraviolet luminescence of N2 irradiated by short x-ray pulses (open access)

Near-ultraviolet luminescence of N2 irradiated by short x-ray pulses

None
Date: April 22, 2010
Creator: Hau-Riege, S.; Bionta, R.; Ryutov, D.; London, R.; Ables, E.; Kishiyama, K. et al.
Object Type: Article
System: The UNT Digital Library
The Cyber Science and Security Institute (open access)

The Cyber Science and Security Institute

None
Date: April 22, 2010
Creator: Brase, J M & Spain, C W
Object Type: Report
System: The UNT Digital Library
Deep Borehole Instrumentation Along San Francisco Bay Bridges: 1996 - 2003 and Strong Ground Motion Systhesis Along the San Francisco/Oakland Bay Bridge (open access)

Deep Borehole Instrumentation Along San Francisco Bay Bridges: 1996 - 2003 and Strong Ground Motion Systhesis Along the San Francisco/Oakland Bay Bridge

As a result of collaboration between the Berkeley Seismographic Station, Lawrence Livermore National Laboratory, and Caltrans, instrument packages have been placed in bedrock in six boreholes and two surface sites along the San Francisco/Oakland Bay Bridge. Since 1996 over 200 local earthquakes have been recorded. Prior to this study few seismic recording instruments existed in bed-rock in San Francisco Bay. We utilized the data to perform analysis of ground motion variability, wave passage, site response, and up-and down-hole wave propagation along the Bay Bridge. We also synthesized strong ground motion at nine locations along the Bay Bridge. Key to these studies is LLNL's effort to exploit the information available in weak ground motions (generally from earthquakes &lt; M=4.0) to enhance predictions of seismic hazards. We found that Yerba Island has no apparent site response at the surface relative to a borehole site. The horizontal to vertical spectral ratio method best revealed no site response, while the complex signal spectral ratio method had the lowest variance for spectral ratios and best predicted surface recordings when the borehole recording was used as input. Both methods identified resonances at about the same frequencies. Regional attenuation results in a significant loss of high frequencies …
Date: April 22, 2005
Creator: Hutchings, L; Foxall, W; Kasameyer, P; larsen, S; Hayek, C; Tyler-Turpin, C et al.
Object Type: Report
System: The UNT Digital Library
Saltstone Clean Cap Formulation (open access)

Saltstone Clean Cap Formulation

The current operation strategy for using Saltstone Vault 4 to receive 0.2 Ci/gallon salt solution waste involves pouring a clean grout layer over the radioactive grout prior to initiating pour into another cell. This will minimize the radiating surface area and reduce the dose rate at the vault and surrounding area. The Clean Cap will be used to shield about four feet of Saltstone poured into a Z-Area vault cell prior to moving to another cell. The minimum thickness of the Clean Cap layer will be determined by the cesium concentration and resulting dose levels and it is expected to be about one foot thick based on current calculations for 0.1 Ci Saltstone that is produced in the Saltstone process by stabilization of 0.2 Ci salt solution. This report documents experiments performed to identify a formulation for the Clean Cap. Thermal transient calculations, adiabatic temperature rise measurements, pour height, time between pour calculations and shielding calculations were beyond the scope and time limitations of this study. However, data required for shielding calculations (composition and specific gravity) are provided for shielding calculations. The approach used to design a Clean Cap formulation was to produce a slurry from the reference premix (10/45/45 …
Date: April 22, 2005
Creator: Langton, C
Object Type: Report
System: The UNT Digital Library
Results obtained on Pewee I, EP-III effluent samples (open access)

Results obtained on Pewee I, EP-III effluent samples

None
Date: April 22, 1969
Creator: Smith, R. A.
Object Type: Report
System: The UNT Digital Library
Erratum: Bounds and Estimates for Elastic Constants of Random Polycrystals of Laminates (open access)

Erratum: Bounds and Estimates for Elastic Constants of Random Polycrystals of Laminates

None
Date: April 22, 2005
Creator: Berger, E. L.
Object Type: Article
System: The UNT Digital Library