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2020 Census: Sustaining Current Reform Efforts Will Be Key to a More Cost-Effective Enumeration
Testimony issued by the Government Accountability Office with an abstract that begins "Overall, the U.S. Census Bureaus (Bureau) planning efforts for 2020 are off to a good start, as the Bureau made noteworthy progress within each of the four lessons learned from the 2010 Census. Still, additional steps will be needed within each of the lessons learned in order to sustain those reforms."
Date:
July 18, 2012
Creator:
United States. Government Accountability Office.
Object Type:
Text
System:
The UNT Digital Library
2169 steel waveform experiments.
In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included the elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe<U+F061>-<U+F065>phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mm-thick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for …
Date:
November 1, 2012
Creator:
Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd & Brown, Justin L.
Object Type:
Report
System:
The UNT Digital Library
230Th-234U Age-Dating Uranium by Mass Spectrometry
This is the standard operating procedure used by the Isotope Ratio Mass Spectrometry Group of the Chemical Sciences Division at LLNL for the preparation of a sample of uranium oxide or uranium metal for {sup 230}Th-{sup 234}U age-dating. The method described here includes the dissolution of a sample of uranium oxide or uranium metal, preparation of a secondary dilution, spiking of separate aliquots for uranium and thorium isotope dilution measurements, and purification of uranium and thorium aliquots for mass spectrometry. This SOP may be applied to uranium samples of unknown purity as in a nuclear forensic investigation, and also to well-characterized samples such as, for example, U{sub 3}O{sub 8} and U-metal certified reference materials. The sample of uranium is transferred to a quartz or PFA vial, concentrated nitric acid is added and the sample is heated on a hotplate at approximately 100 C for several hours until it dissolves. The sample solution is diluted with water to make the solution approximately 4 M HNO{sub 3} and hydrofluoric acid is added to make it 0.05 M HF. A secondary dilution of the primary uranium solution is prepared. Separate aliquots for uranium and thorium isotope dilution measurements are taken and spiked with …
Date:
April 18, 2012
Creator:
Williams, R. W. & Gaffney, A. M.
Object Type:
Report
System:
The UNT Digital Library
2d Affine XY-Spin Model/4d Gauge Theory Duality and Deconfinement
We introduce a duality between two-dimensional XY-spin models with symmetry-breaking perturbations and certain four-dimensional SU(2) and SU(2) = Z{sub 2} gauge theories, compactified on a small spatial circle R{sup 1,2} x S{sup 1}, and considered at temperatures near the deconfinement transition. In a Euclidean set up, the theory is defined on R{sup 2} x T{sup 2}. Similarly, thermal gauge theories of higher rank are dual to new families of 'affine' XY-spin models with perturbations. For rank two, these are related to models used to describe the melting of a 2d crystal with a triangular lattice. The connection is made through a multi-component electric-magnetic Coulomb gas representation for both systems. Perturbations in the spin system map to topological defects in the gauge theory, such as monopole-instantons or magnetic bions, and the vortices in the spin system map to the electrically charged W-bosons in field theory (or vice versa, depending on the duality frame). The duality permits one to use the two-dimensional technology of spin systems to study the thermal deconfinement and discrete chiral transitions in four-dimensional SU(N{sub c}) gauge theories with n{sub f} {ge} 1 adjoint Weyl fermions.
Date:
August 16, 2012
Creator:
Anber, Mohamed M.; Poppitz, Erich; U., /Toronto; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept. /San Francisco State U.
Object Type:
Article
System:
The UNT Digital Library
3D COMSOL Simulations for Thermal Deflection of HFIR Fuel Plate in the "Cheverton-Kelley" Experiments
Three dimensional simulation capabilities are currently being developed at Oak Ridge National Laboratory using COMSOL Multiphysics, a finite element modeling software, to investigate thermal expansion of High Flux Isotope Reactor (HFIR) s low enriched uranium fuel plates. To validate simulations, 3D models have also been developed for the experimental setup used by Cheverton and Kelley in 1968 to investigate the buckling and thermal deflections of HFIR s highly enriched uranium fuel plates. Results for several simulations are presented in this report, and comparisons with the experimental data are provided when data are available. A close agreement between the simulation results and experimental findings demonstrates that the COMSOL simulations are able to capture the thermal expansion physics accurately and that COMSOL could be deployed as a predictive tool for more advanced computations at realistic HFIR conditions to study temperature-induced fuel plate deflection behavior.
Date:
August 1, 2012
Creator:
Jain, Prashant K; Freels, James D & Cook, David Howard
Object Type:
Report
System:
The UNT Digital Library
3D Equilibrium Effects Due to RMP Application on DIII-D
The mitigation and suppression of edge localized modes (ELMs) through application of resonant magnetic perturbations (RMPs) in Tokamak plasmas is a well documented phenomenon [1]. Vacuum calculations suggest the formation of edge islands and stochastic regions when RMPs are applied to the axisymmetric equilibria. Self-consistent calculations of the plasma equilibrium with the VMEC [2] and SPEC [3] codes have been performed for an up-down symmetric shot (142603) in DIII-D. In these codes, a self-consistent calculation of the plasma response due to the RMP coils is calculated. The VMEC code globally enforces the constraints of ideal MHD; consequently, a continuously nested family of flux surfaces is enforced throughout the plasma domain. This approach necessarily precludes the observation of islands or field-line chaos. The SPEC code relaxes the constraints of ideal MHD locally, and allows for islands and field line chaos at or near the rational surfaces. Equilibria with finite pressure gradients are approximated by a set of discrete "ideal-interfaces" at the most irrational flux surfaces and where the strongest pressure gradients are observed. Both the VMEC and SPEC calculations are initialized from EFIT reconstructions of the plasma that are consistent with the experimental pressure and current profiles. A 3D reconstruction using …
Date:
June 20, 2012
Creator:
Lazerson, S.; Lazarus, E.; Hudson, S.; Pablant, N. & Gates, D.
Object Type:
Article
System:
The UNT Digital Library
3D Equilibrium Effects Due to RMP Application on DIII-D
The mitigation and suppression of edge localized modes (ELMs) through application of resonant magnetic perturbations (RMPs) in Tokamak plasmas is a well documented phenomenon. Vacuum calculations suggest the formation of edge islands and stochastic regions when RMPs are applied to the axisymmetric equilibria. Self-consistent calculations of the plasma equilibrium with the VMEC and SPEC codes have been performed for an up-down symmetric shot in DIII-D. In these codes, a self-consistent calculation of the plasma response due to the RMP coils is calculated. The VMEC code globally enforces the constraints of ideal MHD; consequently, a continuously nested family of flux surfaces is enforced throughout the plasma domain. This approach necessarily precludes the observation of islands or field-line chaos. The SPEC code relaxes the constraints of ideal MHD locally, and allows for islands and field line chaos at or near the rational surfaces. Equilibria with finite pressure gradients are approximated by a set of discrete "ideal-interfaces" at the most irrational flux surfaces and where the strongest pressure gradients are observed. Both the VMEC and SPEC calculations are initialized from EFIT reconstructions of the plasma that are consistent with the experimental pressure and current profiles. A 3D reconstruction using the STELLOPT code, which …
Date:
June 20, 2012
Creator:
Lazerson, S.; Lazarus, E.; Hudson, S.; Pablant, N. & Gates, D.
Object Type:
Report
System:
The UNT Digital Library
3D Simulation of Missing Pellet Surface Defects in Light Water Reactor Fuel Rods
The cladding on light water reactor (LWR) fuel rods provides a stable enclosure for fuel pellets and serves as a first barrier against fission product release. Consequently, it is important to design fuel to prevent cladding failure due to mechanical interactions with fuel pellets. Cladding stresses can be effectively limited by controlling power increase rates. However, it has been shown that local geometric irregularities caused by manufacturing defects known as missing pellet surfaces (MPS) in fuel pellets can lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. Nuclear fuel performance codes commonly use a 1.5D (axisymmetric, axially-stacked, one-dimensional radial) or 2D axisymmetric representation of the fuel rod. To study the effects of MPS defects, results from 1.5D or 2D fuel performance analyses are typically mapped to thermo-mechanical models that consist of a 2D plane-strain slice or a full 3D representation of the geometry of the pellet and clad in the region of the defect. The BISON fuel performance code developed at Idaho National Laboratory employs either a 2D axisymmetric or 3D representation of the full fuel rod. This allows for a computational model of …
Date:
September 1, 2012
Creator:
Spencer, B. W.; Hales, J. D.; Novascone, S. R. & Williamson, R. L.
Object Type:
Article
System:
The UNT Digital Library
3D simulations of multipacting in the 56 MHz SRF cavity
The 56 MHz SRF Quarter-Wave Resonator (QWR) is designed for RHIC as a storage cavity to improve the collider performance. 2D multipacting simulation has been done for the cavity alone. Ripples were added to the outer body of the cavity for multipacting suppression based on the simulation findings. During operation, there will be four higher order mode (HOM) couplers. All of these components will be exposed to high RF fields. In this paper we compare 2D and 3D codes simulation results for multipacting in the cavity. We also report 3D simulation results for multipacting simulation at the couplers.
Date:
May 20, 2012
Creator:
Q., Wu; Belomestnykh, S.; Ge, L.; Ko, K.; Li, Z.; Ng, C. et al.
Object Type:
Article
System:
The UNT Digital Library
3D WAVE PROPAGATION AND SITE EFFECTS IN THE HUMBOLDT BAY AREA USING STRONG GROUND MOTION RECORDS FROM THE M6.5 2010 FERNDALE EARTHQUAKE.
None
Date:
September 26, 2012
Creator:
Pitarka, Arben; Thio, Hong Kie & Somerville, Paul G.
Object Type:
Article
System:
The UNT Digital Library
3DPDF: Open Source Solutions for Incorporating 3D Information in PDF Files
None
Date:
November 29, 2012
Creator:
Graf, Norman A.
Object Type:
Article
System:
The UNT Digital Library
9977 TYPE B PACKAGING INTERNAL DATA COLLECTION FEASIBILITY TESTING - MAGNETIC FIELD COMMUNICATIONS
The objective of this report is to document the findings from proof-of-concept testing performed by the Savannah River National Laboratory (SRNL) R&D Engineering and Visible Assets, Inc. for the DOE Packaging Certification Program (PCP) to determine if RuBee (IEEE 1902.1) tags and readers could be used to provide a communication link from within a drum-style DOE certified Type B radioactive materials packaging. A Model 9977 Type B Packaging was used to test the read/write capability and range performance of a RuBee tag and reader. Testing was performed with the RuBee tags placed in various locations inside the packaging including inside the drum on the outside of the lid of the containment vessel and also inside of the containment vessel. This report documents the test methods and results. A path forward will also be recommended.
Date:
June 18, 2012
Creator:
Shull, D.
Object Type:
Report
System:
The UNT Digital Library
9978 AND 9975 TYPE B PACKAGING INTERNAL DATA COLLECTION FEASIBILITY TESTING
The objective of this report is to document the findings from a series of proof-of-concept tests performed by Savannah River National Laboratory (SRNL) R and D Engineering, for the DOE Packaging Certification Program to determine if a viable radio link could be established from within the stainless steel confines of several drum-style DOE certified Type B radioactive materials packagings. Two in-hand, off-the-shelf radio systems were tested. The first system was a Wi-Fi Librestream Onsight{trademark} camera with a Fortress ES820 Access Point and the second was the On-Ramp Wireless Ultra-Link Processing{trademark} (ULP) radio system. These radio systems were tested within the Model 9975 and 9978 Type B packagings at the SRNL. This report documents the test methods and results. A path forward will also be recommended.
Date:
May 7, 2012
Creator:
Fogle, R.
Object Type:
Report
System:
The UNT Digital Library
L.A. Courthouse: Initial Project Justification Is Outdated and Flawed
Testimony issued by the Government Accountability Office with an abstract that begins "Because of delays and cost increases, the General Services Administration (GSA) canceled the authorized 41-courtroom Los Angeles (L.A.), California, courthouse project in 2006. Since then, GSA and the judiciary have been slow to agree upon how to proceed with the project, for which about $366 million in appropriated funds remains available. In 2012, with the judiciarys support, GSA issued a request for proposal for contractors to design and build a 24-courtoom, 32-chamber courthouse, which would be used in conjunction with 25 existing courtrooms in the Roybal Courthouse. However, this new plan will not address one of the principal justifications for the original projectthat the L.A. Court be centralized at one site. Instead, it would increase the distance between the Roybal Courthouse and the planned second court location and the distance to the federal detention center from which prisoners must be transported."
Date:
August 17, 2012
Creator:
United States. Government Accountability Office.
Object Type:
Text
System:
The UNT Digital Library
Ab-initio calculation of optical properties of wurtzitic In_x Ga_1x N and In_x Al_1x N alloys including excitonic effects
None
Date:
September 5, 2012
Creator:
de Carvalho, L C; Schleife, A; Furthmueller, J & Bechstedt, F
Object Type:
Article
System:
The UNT Digital Library
Ab Initio Calculations Of Light-Ion Reactions
The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. In addition to the complex nature of nuclear forces, one faces the quantum-mechanical many-nucleon problem governed by an interplay between bound and continuum states. In recent years, significant progress has been made in ab initio nuclear structure and reaction calculations based on input from QCD employing Hamiltonians constructed within chiral effective field theory. In this contribution, we present one of such promising techniques capable of describing simultaneously both bound and scattering states in light nuclei. By combining the resonating-group method (RGM) with the ab initio no-core shell model (NCSM), we complement a microscopic cluster approach with the use of realistic interactions and a microscopic and consistent description of the clusters. We discuss applications to light nuclei scattering, radiative capture and fusion reactions.
Date:
March 12, 2012
Creator:
Navratil, P; Quaglioni, S; Roth, R & Horiuchi, W
Object Type:
Article
System:
The UNT Digital Library
Ab-initio description of quasiparticle band structures and optical near-edge absorption of transparent conducting oxides
None
Date:
February 14, 2012
Creator:
Schleife, A & Bechstedt, F
Object Type:
Article
System:
The UNT Digital Library
AB INITIO STUDY OF ADVANCED METALLIC NUCLEAR FUELS FOR FAST BREEDER REACTORS
Density-functional formalism is applied to study the ground state properties of {gamma}-U-Zr and {gamma}-U-Mo solid solutions. Calculated heats of formation are compared with CALPHAD assessments. We discuss how the heat of formation in both alloys correlates with the charge transfer between the alloy components. The decomposition curves for {gamma}-based U-Zr and U-Mo solid solutions are derived from Ising-type Monte Carlo simulations. We explore the idea of stabilization of the {delta}-UZr{sub 2} compound against the {alpha}-Zr (hcp) structure due to increase of Zr d-band occupancy by the addition of U to Zr. We discuss how the specific behavior of the electronic density of states in the vicinity of the Fermi level promotes the stabilization of the U{sub 2}Mo compound. The mechanism of possible Am redistribution in the U-Zr and U-Mo fuels is also discussed.
Date:
April 23, 2012
Creator:
Landa, A; Soderlind, P; Grabowski, B; Turchi, P A; Ruban, A V & Vitos, L
Object Type:
Article
System:
The UNT Digital Library
Ab Initio Thermodynamic Study of the CO2 Capture Properties of Potassium Carbonate Sesquihydrate, K2CO3·1.5H2O
By combining density functional theory and lattice phonon dynamics, the thermodynamic properties of CO2 absorption/desorption reactions with dehydrated potassium carbonates through K2CO3·1.5H2O + CO2 = 2KHCO3 + 0.5H2O(g) are analyzed. The energy change and the chemical potential of this reaction have been calculated and used to evaluate its thermodynamic properties and phase transitions. The results indicate that the K2CO3·1.5H2O can only be applied for postcombustion CO2 capture technology at temperatures lower than its phase transition temperature, which depends on the CO2 pressure and the steam pressure with the best range being PH2O ≤ 1.0 bar. Above the phase transition temperature, the sorbent will be regenerated into anhydrous K2CO3. If the steam pressure PH2O is much greater than 1.0 bar, it is possible to use the K2CO3·1.5H2O sorbent for precombustion CO2 capture technology. Compared to anhydrous K2CO3, K2CO3·1.5H2O requires less energy for regeneration.
Date:
January 1, 2012
Creator:
Duan, Yuhua; Luebkes, David R.; Pennline, Henry W.; Li, Bingyun Li; Janik, Michael J. & Halley, Woods
Object Type:
Article
System:
The UNT Digital Library
Abbott Quadrangle
Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:24000
Date:
2012
Creator:
Geological Survey (U.S.)
Object Type:
Map
System:
The Portal to Texas History
Abell Quadrangle
Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:24000
Date:
2012
Creator:
Geological Survey (U.S.)
Object Type:
Map
System:
The Portal to Texas History
Abernathy Quadrangle
Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:24000
Date:
2012
Creator:
Geological Survey (U.S.)
Object Type:
Map
System:
The Portal to Texas History
Abernathy Southwest Quadrangle
Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:24000
Date:
2012
Creator:
Geological Survey (U.S.)
Object Type:
Map
System:
The Portal to Texas History
Abilene East Quadrangle
Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:24000
Date:
2012
Creator:
Geological Survey (U.S.)
Object Type:
Map
System:
The Portal to Texas History