2-D or not 2-D, that is the question: A Northern California test (open access)

2-D or not 2-D, that is the question: A Northern California test

Reliable estimates of the seismic source spectrum are necessary for accurate magnitude, yield, and energy estimation. In particular, how seismic radiated energy scales with increasing earthquake size has been the focus of recent debate within the community and has direct implications on earthquake source physics studies as well as hazard mitigation. The 1-D coda methodology of Mayeda et al. has provided the lowest variance estimate of the source spectrum when compared against traditional approaches that use direct S-waves, thus making it ideal for networks that have sparse station distribution. The 1-D coda methodology has been mostly confined to regions of approximately uniform complexity. For larger, more geophysically complicated regions, 2-D path corrections may be required. The complicated tectonics of the northern California region coupled with high quality broadband seismic data provides for an ideal ''apples-to-apples'' test of 1-D and 2-D path assumptions on direct waves and their coda. Using the same station and event distribution, we compared 1-D and 2-D path corrections and observed the following results: (1) 1-D coda results reduced the amplitude variance relative to direct S-waves by roughly a factor of 8 (800%); (2) Applying a 2-D correction to the coda resulted in up to 40% variance …
Date: June 6, 2005
Creator: Mayeda, K; Malagnini, L; Phillips, W S; Walter, W R & Dreger, D
System: The UNT Digital Library
Adsorption of biometals to monosodium titanate in biological environments (open access)

Adsorption of biometals to monosodium titanate in biological environments

Monosodium titanate (MST) is an inorganic sorbent/ion exchanger developed for the removal of radionuclides from nuclear wastes. We investigated the ability of MST to bind Cd(II), Hg(II), or Au(III) to establish the utility of MST for applications in environmental decontamination or medical therapy (drug delivery). Adsorption isotherms for MST were determined at pH 7-7.5 in water or phosphate-buffered saline. The extent of metal binding was determined spectroscopically by measuring the concentrations of the metals in solution before and after contact with the MST. Cytotoxic responses to MST were assessed using THP1 monocytes and succinate dehydrogenase activity. Monocytic activation by MST was assessed by TNF{alpha} secretion (ELISA) with or without lipopolysaccharide (LPS) activation. MST sorbed Cd(II), Hg(II), and Au(III) under conditions similar to that in physiological systems. MST exhibited the highest affinity for Cd(II) followed by Hg(II) and Au (III). MST (up to 100 mg/L) exhibited only minor (< 25% suppression of succinate dehydrogenase) cytotoxicity and did not trigger TNF{alpha} secretion nor modulate LPS-induced TNF{alpha} secretion from monocytes. MST exhibits high affinity for biometals with no significant biological liabilities in these introductory studies. MST deserves further scrutiny as a substance with the capacity to decontaminate biological environments or deliver metals in …
Date: June 6, 2005
Creator: Hobbs, D. T.; Messer, R. L. W.; Lewis, J. B.; Click, D. R. Lockwood, P. E. & Wataha, J. C.
System: The UNT Digital Library
ADVANCES TOWARDS THE MEASUREMENT AND CONTROL LHC TUNE AND CHROMATICITY (open access)

ADVANCES TOWARDS THE MEASUREMENT AND CONTROL LHC TUNE AND CHROMATICITY

Requirements for tune and chromaticity control in most superconducting hadron machines, and in particular the LHC, are stringent. In order to reach nominal operation, the LHC will almost certainly require feedback on both tune and chromaticity. Experience at RHIC has also shown that coupling control is crucial to successful tune feedback. A prototype baseband phase-locked loop (PLL) tune measurement system has recently been brought into operation at RHIC as part of the US LHC Accelerator Research Program (LARP). We report on the performance of that system and compare it with the extensive accumulation of data from the RHIC 245MHz PLL.
Date: June 6, 2005
Creator: Cameron, P.; Cupolo, J.; Degen, C.; Dellapenna, A.; Hoff, L.; Mead, J. et al.
System: The UNT Digital Library
Analysis of the ANL Test Method for 6CVS Containment Vessels (open access)

Analysis of the ANL Test Method for 6CVS Containment Vessels

In the fall of 2010, Argonne National Laboratory (ANL) contracted with vendors to design and build 6CVS containment vessels as part of their effort to ship Fuel Derived Mixed Fission Product material. The 6CVS design is based on the Savannah River National Laboratory's (SRNL) design for 9975 and 9977 six inch diameter containment vessels. The main difference between the designs is that the 6CVS credits the inner O-ring seal as the containment boundary while the SRNL design credits the outer O-ring seal. Since the leak test must be done with the inner O-ring in place, the containment vessel does not have a pathway for getting the helium into the vessel during the leak test. The leak testing contractor was not able to get acceptable leak rates with the specified O-ring, but they were able to pass the leak test with a slightly larger O-ring. ANL asked the SRNL to duplicate the leak test vendor's method to determine the cause of the high leak rates. The SRNL testing showed that the helium leak indications were caused by residual helium left within the 6CVS Closure Assembly by the leak test technique, and by helium permeation through the Viton O-ring seals. After SRNL …
Date: June 6, 2011
Creator: Trapp, D. & Crow, G.
System: The UNT Digital Library
Angularly Adaptive P1--Double P0 Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems in Planar Geometry (open access)

Angularly Adaptive P1--Double P0 Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems in Planar Geometry

The double spherical harmonics angular approximation in the lowest order, i.e. double P{sub 0} (DP{sub 0}), is developed for the solution of time-dependent non-equilibrium grey radiative transfer problems in planar geometry. The standard P{sub 1} angular approximation represents the angular dependence of the radiation specific intensity using a linear function in the angular domain -1 {le} {mu} {le} 1. In contrast, the DP{sub 0} angular approximation represents the angular dependence as isotropic in each half angular range -1 {le} {mu} < 0 and 0 < {mu} {le} 1. Neglecting the time derivative of the radiation flux, both the P{sub 1} and DP{sub 0} equations can be written as a single diffusion equation for the radiation energy density. Although the DP{sub 0} diffusion approximation is expected to be less accurate than the P{sub 1} diffusion approximation at and near thermodynamic equilibrium, the DP{sub 0} angular approximation can more accurately capture the complicated angular dependence near the non-equilibrium wave front. We develop an adaptive angular technique that locally uses either the DP{sub 0} or the P{sub 1} diffusion approximation depending on the degree to which the radiation and material fields are in thermodynamic equilibrium. Numerical results are presented for a test problem …
Date: June 6, 2005
Creator: Brantley, P S
System: The UNT Digital Library
Application of Cryocoolers to a Vintage Dilution Refrigerator (open access)

Application of Cryocoolers to a Vintage Dilution Refrigerator

A dilution refrigerator is required for 50mK detector operation of CDMS (Cryogenic Dark Matter Search). Besides shielding the dilution refrigerator itself, the liquid nitrogen shield and liquid helium bath in the refrigerator cool the detector cryostat heat shields and cool electronics, resulting in significant external heat loads at 80K and at 4K. An Oxford Instruments Kelvinox 400 has served this role for ten years but required daily transfers of liquid nitrogen and liquid helium. Complicating the cryogen supply is the location 800 meters below ground in an RF shielded, class 10000 clean room at Soudan, MN. Nitrogen and helium re-liquefiers using cryocoolers were installed outside the clean room and continuously condense room temperature gas and return the liquids to the dilution refrigerator through a transfer line. This paper will describe the design, installation, controls and performance of liquefaction systems.
Date: June 6, 2011
Creator: Schmitt, Richard; Smith, Gary; Ruschman, Mark & Beaty, Jim
System: The UNT Digital Library
Asymptotic Behavior of the Electron Cloud Instability (open access)

Asymptotic Behavior of the Electron Cloud Instability

The fast beam-ion instability and the single bunch electron-cloud instability are substantially nonlinear phenomena and can be analyzed in a similar way. The initial exponential growth of the amplitudes known for both instabilities takes place only in the linear approximation. Later, in the nonlinear regime, amplitudes grow according to a power law or even decrease. We analyze the nonlinear regime describing the growth of amplitudes in time and along the train of bunches. Analytic analysis is compared with simulations.
Date: June 6, 2007
Creator: Heifets, Samuel
System: The UNT Digital Library
Azimuthally sensitive hanbury brown-twiss interferometry in Au + Au collisions sqrt S sub NN = 200 GeV (open access)

Azimuthally sensitive hanbury brown-twiss interferometry in Au + Au collisions sqrt S sub NN = 200 GeV

We present the results of a systematic study of the shape of the pion distribution in coordinate space at freeze-out in Au+Au collisions at RHIC using two-pion Hanbury Brown-Twiss (HBT) interferometry. Oscillations of the extracted HBT radii vs. emission angle indicate sources elongated perpendicular to the reaction plane. The results indicate that the pressure and expansion time of the collision system are not sufficient to completely quench its initial shape.
Date: June 6, 2004
Creator: Argonne National Laboratory
System: The UNT Digital Library
BALLISTICS TESTING OF THE 9977 SHIPPING PACKAGE FOR STORAGE APPLICATIONS (open access)

BALLISTICS TESTING OF THE 9977 SHIPPING PACKAGE FOR STORAGE APPLICATIONS

Radioactive materials are stored in a variety of locations throughout the DOE complex. At the Savannah River Site (SRS), materials are stored within dedicated facilities. Each of those facilities has a documented safety analysis (DSA) that describes accidents that the facility and the materials within it may encounter. Facilities at the SRS are planning on utilizing the certified Model 9977 Shipping Package as a long term storage package and one of these facilities required ballistics testing. Specifically, in order to meet the facility DSA, the radioactive materials (RAM) must be contained within the storage package after impact by a .223 caliber round. In order to qualify the Model 9977 Shipping Package for storage in this location, the package had to be tested under these conditions. Over the past two years, the Model 9977 Shipping Package has been subjected to a series of ballistics tests. The purpose of the testing was to determine if the 9977 would be suitable for use as a storage package at a Savannah River Site facility. The facility requirements are that the package must not release any of its contents following the impact in its most vulnerable location by a .223 caliber round. A package, assembled …
Date: June 6, 2012
Creator: Loftin, B.; Abramczyk, G. & Koenig, R.
System: The UNT Digital Library
Beta decay of neutron-rich transuranic nuclei (open access)

Beta decay of neutron-rich transuranic nuclei

Allowance is made for beta-delayed fission in the calculation of the mass yield of underground thermonuclear explosions. This allowance is made by calculating a correction factor by four different methods. These correction factors are applied to a simple model of product yield and the accuracy and potential usefulness of the results are discussed. 19 refs., 3 figs., 1 tab. (DWL)
Date: June 6, 1986
Creator: Hoff, R.W.
System: The UNT Digital Library
Bobbin-Tool Friction-Stir Welding of Thick-Walled Aluminum Alloy Pressure Vessels (open access)

Bobbin-Tool Friction-Stir Welding of Thick-Walled Aluminum Alloy Pressure Vessels

It was desired to assemble thick-walled Al alloy 2219 pressure vessels by bobbin-tool friction-stir welding. To develop the welding-process, mechanical-property, and fitness-for-service information to support this effort, extensive friction-stir welding-parameter studies were conducted on 2.5 cm. and 3.8 cm. thick 2219 Al alloy plate. Starting conditions of the plate were the fully-heat-treated (-T62) and in the annealed (-O) conditions. The former condition was chosen with the intent of using the welds in either the 'as welded' condition or after a simple low-temperature aging treatment. Since preliminary stress-analyses showed that stresses in and near the welds would probably exceed the yield-strength of both 'as welded' and welded and aged weld-joints, a post-weld solution-treatment, quenching, and aging treatment was also examined. Once a suitable set of welding and post-weld heat-treatment parameters was established, the project divided into two parts. The first part concentrated on developing the necessary process information to be able to make defect-free friction-stir welds in 3.8 cm. thick Al alloy 2219 in the form of circumferential welds that would join two hemispherical forgings with a 102 cm. inside diameter. This necessitated going to a bobbin-tool welding-technique to simplify the tooling needed to react the large forces generated in friction-stir …
Date: June 6, 2007
Creator: Dalder, E C; Pastrnak, J W; Engel, J; Forrest, R S; Kokko, E; Ternan, K M et al.
System: The UNT Digital Library
Breeder Reactor Fuel Fabrication Development Overview (open access)

Breeder Reactor Fuel Fabrication Development Overview

This report addresses the breeder reactor fuel fabrication development overview.
Date: June 6, 1980
Creator: Carlson, MCJ
System: The UNT Digital Library
BWR containment failure analysis during degraded-core accidents (open access)

BWR containment failure analysis during degraded-core accidents

This paper presents a containment failure mode analysis during a spectrum of postulated degraded core accident sequences in a typical 1000-MW(e) boiling water reactor (BWR) with a Mark-I wetwell containment. Overtemperature failure of containment electric penetration assemblies (CEPAs) has been found to be the major failure mode during such accidents.
Date: June 6, 1982
Creator: Yue, D.D.
System: The UNT Digital Library
Characteristics of transition radiation in the x-ray spectral region (open access)

Characteristics of transition radiation in the x-ray spectral region

Measurements of soft x-ray production by transition radiation have been performed in a series of experiments at the Lawrence Livermore National Laboratory. The results have shown that transition radiation is an intense and predictable source of photons in the soft x-ray energy range. This paper will give a brief review of the general properties of the x-ray distributions generated by these sources. 9 refs., 9 figs.
Date: June 6, 1986
Creator: Moran, M. J.
System: The UNT Digital Library
Charm and Charmonium Spectroscopy at the e+e- B-Factories (open access)

Charm and Charmonium Spectroscopy at the e+e- B-Factories

Over the past few years, there has been a lot of progress in the areas of charm and charmonium spectroscopy, in large part due to the very large data samples being accumulated at the e{sup +}e{sup -} B-Factories. In this presentation I will focus on results in three areas: the X/Y/Z charmonium-candidate states, the D{sub sJ} charmed-strange mesons, and newly-discovered charmed baryons. Note the absence of a section on pentaquarks: all B-Factory searches for pentaquarks, charmed or otherwise, have not yielded any observation of such states.
Date: June 6, 2006
Creator: Marsiske, Helmut
System: The UNT Digital Library
Chiral Anomaly Effects And the BaBar Measurements of the $\gamma\gamma^{*}\to \pi^{0}$ Transition Form Factor (open access)

Chiral Anomaly Effects And the BaBar Measurements of the $\gamma\gamma^{*}\to \pi^{0}$ Transition Form Factor

None
Date: June 6, 2013
Creator: Pham, T. N. & Pham, X. Y.
System: The UNT Digital Library
Coherence Properties of Individual Femtosecond Pulses of an X-ray Free-Electron Laser (open access)

Coherence Properties of Individual Femtosecond Pulses of an X-ray Free-Electron Laser

Measurements of the spatial and temporal coherence of single, femtosecond x-ray pulses generated by the first hard x-ray free-electron laser, the Linac Coherent Light Source, are presented. Single-shot measurements were performed at 780 eV x-ray photon energy using apertures containing double pinholes in 'diffract-and-destroy' mode. We determined a coherence length of 17 {micro}m in the vertical direction, which is approximately the size of the focused Linac Coherent Light Source beam in the same direction. The analysis of the diffraction patterns produced by the pinholes with the largest separation yields an estimate of the temporal coherence time of 0.55 fs. We find that the total degree of transverse coherence is 56% and that the x-ray pulses are adequately described by two transverse coherent modes in each direction. This leads us to the conclusion that 78% of the total power is contained in the dominant mode.
Date: June 6, 2012
Creator: Vartanyants, I. A.; Singer, A.; Mancuso, A. P.; Yefanov, O. M.; Sakdinawat, A.; Liu, Y. et al.
System: The UNT Digital Library
Computations of Eigenpair Subsets with the MRRR Algorithm (open access)

Computations of Eigenpair Subsets with the MRRR Algorithm

The main advantage of inverse iteration over the QR algorithm and Divide & Conquer for the symmetric tridiagonal eigenproblem is that subsets of eigenpairs can be computed at reduced cost. The MRRR algorithm (MRRR = Multiple Relatively Robust Representations) is a clever variant of inverse iteration without the need for reorthogonalization. STEGR, the current version of MRRR in LAPACK 3.0, does not allow for subset computations. The next release of STEGR is designed to compute a (sub-)set of k eigenpairs with {Omicron}(kn) operations. Because of the special way in which eigenvectors are computed, MRRR subset computations are more complicated than when using inverse iteration. Unlike the latter, MRRR sometimes cannot ignore the unwanted part of the spectrum. We describe the problems with what we call 'false singletons'. These are eigenvalues that appear to be isolated with respect to the wanted eigenvalues but in fact belong to a tight cluster of unwanted eigenvalues. This paper analyzes these complications and ways to deal with them.
Date: June 6, 2006
Creator: Marques, Osni A.; Parlett, Beresford N. & Vomel, Christof
System: The UNT Digital Library
Computing Heavy Elements (open access)

Computing Heavy Elements

None
Date: June 6, 2011
Creator: Schunck, N.; Baran, A.; Kortelainen, M.; McDonnell, J.; More, J.; Nazarewicz, W. et al.
System: The UNT Digital Library
Conditional and opposed reaction path diagrams for the analysis of fluid-chemistry interactions (open access)

Conditional and opposed reaction path diagrams for the analysis of fluid-chemistry interactions

This conference paper considers how to use reaction path diagrams to better understand the output of reacting flow simulations. Briefly, these diagrams have long been used to depict the reactants and products in networks of chemical reactions. The diagrams can be generated in several ways from computer simulations of chemically reacting fluids to depict how the fluid moderates the chemistry by determining which species are brought into contact to react in quantity. The concept of a conditional diagram is introduced which depicts the reactions occurring in only a portion of the fluid domain, thus enabling comparisons between different regions of the fluid and the overall reaction network. Several examples are provided of the paths occurring in methane diffusion flames.
Date: June 6, 2003
Creator: Grcar, Joseph F.; Day, Marcus S. & Bell, John B.
System: The UNT Digital Library
Constraining PCP Violating Varying Alpha Theory through Laboratory Experiments (open access)

Constraining PCP Violating Varying Alpha Theory through Laboratory Experiments

In this report we have studied the implication of a parity and charge-parity (PCP) violating interaction in varying alpha theory. Due to this interaction, the state of photon polarization can change when it passes through a strong background magnetic field. We have calculated the optical rotation and ellipticity of the plane of polarization of an electromagnetic wave and tested our results against different laboratory experiments. Our model contains a PCP violating parameter {beta} and a scale of alpha variation {omega}. By analyzing the laboratory experimental data, we found the most stringent constraints on our model parameters to be 1 {le} {omega} {le} 10{sup 13} GeV{sup 2} and -0.5 {le} {beta} {le} 0.5. We also found that with the existing experimental input parameters it is very difficult to detect the ellipticity in the near future.
Date: June 6, 2012
Creator: Maity, Debaprasad; /NCTS, Taipei /Taiwan, Natl. Taiwan U.; Chen, Pisin & /NCTS, Taipei /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC
System: The UNT Digital Library
Controlling company drawing symbology (open access)

Controlling company drawing symbology

Fluor Daniel Hanford. Inc., is the prime contractor for the US, Department of Energy, Richland Operations Office at the Hanford Site, which is located near Richland, Washington, in the southeastern portion of the state. Six major subcontractors for Fluor Daniel Hanford, Inc., provide operations and maintenance in waste management, environmental restoration, science and energy for 24 major facilities, programs or utilities on the Site that covers 1,465 square kilometers (560 square miles). Hanford was established in secrecy during the Second World War to produce plutonium for America's nuclear weapons. Peak production was reached in the 1960s when nine production reactors were in operation at the Site. All weapons material production was halted in the late 1980s and the Site is now engaged in the world's largest environmental cleanup project. The mission at Hanford is to manage waste products; researching, developing, applying, and commercializing technologies; waste management; cleanup and environmental restoration. Engineering, scientific and research programs are conducted on environmental restoration, tank waste remediation, waste management, nuclear energy, and energy research.
Date: June 6, 1999
Creator: Nielsen, Bruce L.
System: The UNT Digital Library
Cosmological Imprints of a Generalized Chaplygin Gas Model for the Early Universe (open access)

Cosmological Imprints of a Generalized Chaplygin Gas Model for the Early Universe

We propose a phenomenological model for the early universe where there is a smooth transition between an early quintessence phase and a radiation-dominated era. The matter content is modeled by an appropriately modified Chaplygin gas for the early universe. We constrain the model observationally by mapping the primordial power spectrum of the scalar perturbations to the latest data of WMAP7. We compute as well the spectrum of the primordial gravitational waves as would be measured today. We show that the high frequencies region of the spectrum depends on the free parameter of the model and most importantly this region of the spectrum can be within the reach of future gravitational waves detectors.
Date: June 6, 2012
Creator: Bouhmadi-Lopez, Mariam; /Lisbon, CENTRA; Chen, Pisin; /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC; Liu, Yen-Wei & /Taiwan, Natl. Taiwan U.
System: The UNT Digital Library
Crystal structure of Thermotoga maritima TM0439: implications for the mechanism of bacterial GntR transcription regulators with Zn2+-binding FCD domains (open access)

Crystal structure of Thermotoga maritima TM0439: implications for the mechanism of bacterial GntR transcription regulators with Zn2+-binding FCD domains

The GntR superfamily of dimeric transcription factors, with more than 6200 members encoded in bacterial genomes, are characterized by N-terminal winged helix (WH) DNA-binding domains and diverse C-terminal, regulatory domains, which provide a basis for the classification of the constituent families. The largest of these families, FadR, contains nearly 3000 proteins with all a-helical regulatory domains classified into two related Pfam families: FadR{_}C and FCD. Only two crystal structures of the FadR family members, i.e. the E. coli FadR protein and the LldR from C. glutamicum, have been described to date in literature. Here we describe the crystal structure of TM0439, a GntR regulator with an FCD domain, found in the Thermotoga maritima genome. The FCD domain is similar to that of the LldR regulator, and contains a buried metal binding site. Using atomic absorption spectroscopy and Trp fluorescence, we show that the recombinant protein contains bound Ni{sup 2+} ions, but it is able to bind Zn{sup 2+} with K{sub D} < 70 nM . We conclude that Zn{sup 2+} is the likely physiological metal, where it may perform either or both structural and regulatory roles. Finally, we compare the TM0439 structure to two other FadR family structures recently deposited …
Date: June 6, 2009
Creator: Zheng, Meiying; Cooper, David; Grossoehmerb, Nickolas; Yu, Minmin; Hung, Li-Wei; Cieslik, Murcin et al.
System: The UNT Digital Library