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RADIOACTIVE ELEMENTS IN THE STANDARD ATOMIC WEIGHTS TABLE (open access)

RADIOACTIVE ELEMENTS IN THE STANDARD ATOMIC WEIGHTS TABLE

In the 1949 Report of the Atomic Weights Commission, a series of new elements were added to the Atomic Weights Table. Since these elements had been produced in the laboratory and were not discovered in nature, the atomic weight value of these artificial products would depend upon the production method. Since atomic weight is a property of an element as it occurs in nature, it would be incorrect to assign an atomic weight value to that element. As a result of that discussion, the Commission decided to provide only the mass number of the most stable (or longest-lived) known isotope as the number to be associated with these entries in the Atomic Weights Table. As a function of time, the mass number associated with various elements has changed as longer-lived isotopes of a particular element has been found in nature, or as improved half-life values of an element's isotopes might cause a shift in the longest-lived isotope from one mass to another. In the 1957 Report of the Atomic Weights Commission, it was decided to discontinue the listing of the mass number in the Atomic Weights Table on the grounds that the kind of information supplied by the mass number …
Date: July 27, 2011
Creator: Holden, N. E.; Holden, N. & Holden, N. E.
System: The UNT Digital Library
Ideal MHD Stability of ITER Steady State Scenarios with ITBs (open access)

Ideal MHD Stability of ITER Steady State Scenarios with ITBs

One of ITER goals is to demonstrate feasibility of continuous operations using non-inductive current drive. Two main candidates have been identified for advanced operations: the long duration, high neutron fluency hybrid scenario and the steady state scenario, both operating at a plasma current lower than the reference ELMy scenario [1][2] to minimize the required current drive. The steady state scenario targets plasmas with current 7-10 MA in the flat-top, 50% of which will be provided by the self-generated, pressure-driven bootstrap current. It has been estimated that, in order to obtain a fusion gain Q > 5 at a current of 9 MA, it should be ΒN > 2.5 and H > 1.5 [3]. This implies the presence of an Internal Transport Barrier (ITB). This work discusses how the stability of steady state scenarios with ITBs is affected by the external heating sources and by perturbations of the equilibrium profiles.
Date: July 27, 2011
Creator: Poli, F. M.; Kessel, C. E.; Jardin, S.; Manickam, J.; Chance, M. & Chen, J.
System: The UNT Digital Library
Suppression of probe background signals via B1 field inhomogeneity (open access)

Suppression of probe background signals via B1 field inhomogeneity

A new approach combining a long pulse with the DEPTH sequence (Cory and Ritchey, Journal of Magnetic Resonance, 1988) greatly improves the efficiency for suppressing probe background signals arising from spinning modules. By applying a long initial excitation pulse in the DEPTH sequence, instead of a {pi}/2 pulse, the inhomogeneous B{sub 1} fields outside the coil can dephase the background coherence in the nutation frame. The initial long pulse and the following two consecutive EXORCYCLE {pi} pulses function complementarily and prove most effective in removing background signals from both strong and weak B{sub 1} fields. Experimentally, the length of the long pulse can be optimized around odd multiples of the {pi}/2 pulse, depending on the individual probe design, to preserve signals inside the coil while minimizing those from probe hardware. This method extends the applicability of the DEPTH sequence to probes with small differences in B{sub 1} field strength between the inside and outside of the coil, and can readily combine with well-developed double resonance experiments for quantitative measurement. In general, spin systems with weak internal interactions are required to attain efficient and uniform excitation for powder samples, and the principles to determine the applicability are discussed qualitatively in terms …
Date: January 27, 2011
Creator: Feng, Jian & Reimer, Jeffrey
System: The UNT Digital Library
Reconciling sampling and direct instrumentation for unintrusive call-path profiling of MPI programs (open access)

Reconciling sampling and direct instrumentation for unintrusive call-path profiling of MPI programs

None
Date: January 27, 2011
Creator: Szebenyi, Z; Gamblin, T; Schulz, M; de Supinski, B; Wolf, F & Wylie, B
System: The UNT Digital Library
9975 SHIPPING PACKAGE LIFE EXTENSION SURVEILLANCE PROGRAM RESULTS SUMMARY (open access)

9975 SHIPPING PACKAGE LIFE EXTENSION SURVEILLANCE PROGRAM RESULTS SUMMARY

Results from the 9975 shipping package Storage and Surveillance Program at the Savannah River Site (SRS) are summarized for justification to extend the life of the 9975 packages currently stored in the K-Area Complex (KAC). This justification is established with the stipulation that surveillance activities will continue throughout the extended time to ensure the continued integrity of the 9975 materials of construction and to further understand the currently identified degradation mechanisms. The 10 year storage life justification was developed prior to storage. A subsequent report was later used to validate the qualification of the 9975 shipping packages for 10 years in storage. However the qualification for the storage period was provided by the monitoring requirements of the 9975 Storage and Surveillance Program. This report summarizes efforts to determine a new safe storage limit for the 9975 shipping package based on the surveillance data collected since 2005 when the 9975 Storage and Surveillance Program began. The Program has demonstrated that the 9975 package has a robust design that can perform under a variety of conditions. The primary emphasis of the on-going 9975 Storage and Surveillance Program is an aging study of the 9975 Viton{reg_sign} containment vessel O-rings and the Celotex{reg_sign} fiberboard …
Date: May 27, 2011
Creator: Dunn, K.; Daugherty, W.; Hackney, B.; Hoffman, E. & Skidmore, E.
System: The UNT Digital Library
TECHNOLOGY DEVELOPMENT AND DEPLOYMENT OF SYSTEMS FOR THE RETRIEVAL AND PROCESSING OF REMOTE-HANDLED SLUDGE FROM HANFORD K-WEST FUEL STORAGE BASIN (open access)

TECHNOLOGY DEVELOPMENT AND DEPLOYMENT OF SYSTEMS FOR THE RETRIEVAL AND PROCESSING OF REMOTE-HANDLED SLUDGE FROM HANFORD K-WEST FUEL STORAGE BASIN

In 2011, significant progress was made in developing and deploying technologies to remove, transport, and interim store remote-handled sludge from the 105-K West Fuel Storage Basin on the Hanford Site in south-central Washington State. The sludge in the 105-K West Basin is an accumulation of degraded spent nuclear fuel and other debris that collected during long-term underwater storage of the spent fuel. In 2010, an innovative, remotely operated retrieval system was used to successfully retrieve over 99.7% of the radioactive sludge from 10 submerged temporary storage containers in the K West Basin. In 2011, a full-scale prototype facility was completed for use in technology development, design qualification testing, and operator training on systems used to retrieve, transport, and store highly radioactive K Basin sludge. In this facility, three separate systems for characterizing, retrieving, pretreating, and processing remote-handled sludge were developed. Two of these systems were successfully deployed in 2011. One of these systems was used to pretreat knockout pot sludge as part of the 105-K West Basin cleanup. Knockout pot sludge contains pieces of degraded uranium fuel ranging in size from 600 {mu}m to 6350 {mu}m mixed with pieces of inert material, such as aluminum wire and graphite, in the …
Date: December 27, 2011
Creator: RE, RAYMOND
System: The UNT Digital Library
A REVISED METHOD FOR ESTIMATING OXIDE BASICITY PER THE SMITH SCALE WITH EXAMPLE APPLICATION TO GLASS DURABILITY (open access)

A REVISED METHOD FOR ESTIMATING OXIDE BASICITY PER THE SMITH SCALE WITH EXAMPLE APPLICATION TO GLASS DURABILITY

Previous researchers have developed correlations between oxide electronegativity and oxide basicity. The present paper revises those correlations using a newer method of calculating electronegativity of the oxygen anion. Basicity is expressed using the Smith {alpha} parameter scale. A linear relation was found between the oxide electronegativity and the Smith {alpha} parameter, with an R{sup 2} of 0.92. An example application of this new correlation to the durability of high-level nuclear waste glass is demonstrated. The durability of waste glass was found to be directly proportional to the quantity and basicity of the oxides of tetrahedrally coordinated network forming ions.
Date: July 27, 2011
Creator: JG, REYNOLDS
System: The UNT Digital Library
Forecast of Standard Atomic Weights for the Mononuclidic Elements – 2011 (open access)

Forecast of Standard Atomic Weights for the Mononuclidic Elements – 2011

In this short report, I will provide an early warning about potential changes to the standard atomic weight values for the twenty mononuclidic and the so-called pseudo-mononuclidic ({sup 232}Th and {sup 231}Pa) chemical elements due to the estimated changes in the mass values to be published in the next Atomic Mass Tables within the next two years. There have been many new measurements of atomic masses, since the last published Atomic Mass Table. The Atomic Mass Data Center has released an unpublished version of the present status of the atomic mass values as a private communication. We can not update the Standard Atomic Weight Table at this time based on these unpublished values but we can anticipate how many changes are probably going to be expected in the next few years on the basis of the forthcoming publication of the Atomic Mass Table. I will briefly discuss the procedures that the Atomic Weights Commission used in deriving the recommended Standard Atomic Weight values and their uncertainties from the atomic mass values. I will also discuss some concern raised about a proposed change in the definition of the mole. The definition of the mole is now connected directly to the mass …
Date: July 27, 2011
Creator: Holden, N. E.; Holden, N. & Holden, N. E.
System: The UNT Digital Library
Shock timing on the National Ignition Facility: the first precision tuning series (open access)

Shock timing on the National Ignition Facility: the first precision tuning series

Ignition implosions on the National Ignition Facility (NIF) [Lindl et al., Phys. Plasmas 11, 339 (2004)] are driven with a very carefully tailored sequence of four shock waves that must be timed to very high precision in order to keep the fuel on a low adiabat. The first series of precision tuning experiments on NIF have been performed. These experiments use optical diagnostics to directly measure the strength and timing of all four shocks inside the hohlraum-driven, cryogenic deuterium-filled capsule interior. The results of these experiments are presented demonstrating a significant decrease in the fuel adiabat over previously un-tuned implosions. The impact of the improved adiabat on fuel compression is confirmed in related deuterium-tritium (DT) layered capsule implosions by measurement of fuel areal density (rR), which show the highest fuel compression (rR {approx} 1.0 g/cm{sup 2}) measured to date.
Date: October 27, 2011
Creator: Robey, H. F.; Celliers, P. M.; Kline, J. L. & Mackinnon, A. J.
System: The UNT Digital Library
FRMAC Interactions During a Radiological or Nuclear Event (open access)

FRMAC Interactions During a Radiological or Nuclear Event

During a radiological or nuclear event of national significance the Federal Radiological Emergency Monitoring and Assessment Center (FRMAC) assists federal, state, tribal, and local authorities by providing timely, high-quality predictions, measurements, analyses and assessments to promote efficient and effective emergency response for protection of the public and the environment from the consequences of such an event.
Date: January 27, 2011
Creator: Wong, C T
System: The UNT Digital Library
Developing extensible lattice-Boltzmann simulationsfor general-purpose graphics-programming units (open access)

Developing extensible lattice-Boltzmann simulationsfor general-purpose graphics-programming units

Lattice-Boltzmann methods are versatile numerical modeling techniques capable of reproducing a wide variety of fluid-mechanical behavior. These methods are well suited to parallel implementation, particularly on the single-instruction multiple data (SIMD) parallel processing environments found in computer graphics processing units (GPUs). Although more recent programming tools dramatically improve the ease with which GPU programs can be written, the programming environment still lacks the flexibility available to more traditional CPU programs. In particular, it may be difficult to develop modular and extensible programs that require variable on-device functionality with current GPU architectures. This paper describes a process of automatic code generation that overcomes these difficulties for lattice-Boltzmann simulations. It details the development of GPU-based modules for an extensible lattice-Boltzmann simulation package - LBHydra. The performance of the automatically generated code is compared to equivalent purpose written codes for both single-phase, multiple-phase, and multiple-component flows. The flexibility of the new method is demonstrated by simulating a rising, dissolving droplet in a porous medium with user generated lattice-Boltzmann models and subroutines.
Date: October 27, 2011
Creator: Walsh, S C & Saar, M O
System: The UNT Digital Library
Electron Beam Charge Diagnostics for Laser Plasma Accelerators (open access)

Electron Beam Charge Diagnostics for Laser Plasma Accelerators

A comprehensive study of charge diagnostics is conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs). First, a scintillating screen (Lanex) was extensively studied using subnanosecond electron beams from the Advanced Light Source booster synchrotron, at the Lawrence Berkeley National Laboratory. The Lanex was cross calibrated with an integrating current transformer (ICT) for up to the electron energy of 1.5 GeV, and the linear response of the screen was confirmed for charge density and intensity up to 160 pC/mm{sup 2} and 0.4 pC/(ps mm{sup 2}), respectively. After the radio-frequency accelerator based cross calibration, a series of measurements was conducted using electron beams from an LPA. Cross calibrations were carried out using an activation-based measurement that is immune to electromagnetic pulse noise, ICT, and Lanex. The diagnostics agreed within {+-}8%, showing that they all can provide accurate charge measurements for LPAs.
Date: June 27, 2011
Creator: Nakamura, Kei; Gonsalves, Anthony; Lin, Chen; Smith, Alan; Rodgers, David; Donahue, Rich et al.
System: The UNT Digital Library
Axisymmetric Magnetic Mirror Applications - Diverter Test Stand to Fusion Power Plant (open access)

Axisymmetric Magnetic Mirror Applications - Diverter Test Stand to Fusion Power Plant

None
Date: May 27, 2011
Creator: Molvik, A. W.; Moir, R. W.; Ryutov, D. D. & Simonen, T. C.
System: The UNT Digital Library
The orientation and morphology of Pt precipitates within sapphire (open access)

The orientation and morphology of Pt precipitates within sapphire

None
Date: January 27, 2011
Creator: Santala, M K; Radmilovic, V R; Giulian, R; Ridgway, M C; Gronsky, R & Glaeser, A M
System: The UNT Digital Library
Obligate Biotrophy Features Unraveled by the Genomic Analysis of the Rust Fungi, Melampsora larici-populina and Puccinia graminis f. sp. tritici (open access)

Obligate Biotrophy Features Unraveled by the Genomic Analysis of the Rust Fungi, Melampsora larici-populina and Puccinia graminis f. sp. tritici

Rust fungi are some of the most devastating pathogens of crop plants. They are obligate biotrophs, which extract nutrients only from living plant tissues and cannot grow apart from their hosts. Their lifestyle has slowed the dissection of molecular mechanisms underlying host invasion and avoidance or suppression of plant innate immunity. We sequenced the 101 mega base pair genome of Melampsora larici-populina, the causal agent of poplar leaf rust, and the 89 mega base pair genome of Puccinia graminis f. sp. tritici, the causal agent of wheat and barley stem rust. We then compared the 16,841 predicted proteins of M. larici-populina to the 18,241 predicted proteins of P. graminis f. sp tritici. Genomic features related to their obligate biotrophic life-style include expanded lineage-specific gene families, a large repertoire of effector-like small secreted proteins (SSPs), impaired nitrogen and sulfur assimilation pathways, and expanded families of amino-acid, oligopeptide and hexose membrane transporters. The dramatic upregulation of transcripts coding for SSPs, secreted hydrolytic enzymes, and transporters in planta suggests that they play a role in host infection and nutrient acquisition. Some of these genomic hallmarks are mirrored in the genomes of other microbial eukaryotes that have independently evolved to infect plants, indicating convergent …
Date: April 27, 2011
Creator: Duplessis, Sebastien; Cuomo, Christina A.; Lin, Yao-Cheng; Aerts, Andrea; Tisserant, Emilie; Veneault-Fourrey, Claire et al.
System: The UNT Digital Library
Antiviral Activity of Metal-Containing Polymers—Organotin and Cisplatin-Like Polymers (open access)

Antiviral Activity of Metal-Containing Polymers—Organotin and Cisplatin-Like Polymers

This article examines the use of metal-containing polymers as a novel class of antivirals. Polymers containing platinum and to a lesser extent tin, have repeatedly demonstrated antitumor activity in vitro and in vivo against a variety of cell and tumor types. The mechanisms responsible for the antitumor activity include inducing a delay in cell proliferation and sister chromatid exchanges blocking tumor growth.
Date: May 27, 2011
Creator: Roner, Michael R.; Carraher, Charles E., Jr.; Shahi, Kimberly & Barot, Girish
System: The UNT Digital Library
Use of prior odds for missing persons identifications (open access)

Use of prior odds for missing persons identifications

This article discusses the use of DNA typing, likelihood ratios, and prior odds for missing persons identifications.
Date: June 27, 2011
Creator: Budowle, Bruce; Ge, Jianye; Chakraborty, Ranajit & Gill-King, Harrell
System: The UNT Digital Library
Development of micro-electrode array based tests for neurotoxicity: assessment of interlaboratory reproducibility with neuroactive chemicals (open access)

Development of micro-electrode array based tests for neurotoxicity: assessment of interlaboratory reproducibility with neuroactive chemicals

Article evaluating the response to the pharmacological compounds Fluoxetine, Muscimol, and Verapamil in primary neuronal cultures. Final conclusions are drawn that MEA technology has a potential for standard in vitro neurotoxicity/neuropharmacology evaluation.
Date: April 27, 2011
Creator: Novellino, A.; Scelfo, Bibiana; Palosaari, T.; Price, A.; Sobanski, Tomasz; Shafer, T.J. et al.
System: The UNT Digital Library
Improving Turn Around Times Of Calorimeter Measurements In The LLNL MC&A Labs Through Reduction Of Thermal Impedance (open access)

Improving Turn Around Times Of Calorimeter Measurements In The LLNL MC&A Labs Through Reduction Of Thermal Impedance

None
Date: June 27, 2011
Creator: Cochran, C. W.; Johnson, R. W. & Sanchez, J. J.
System: The UNT Digital Library
Novel Chemistry at the National Ignition Facility (open access)

Novel Chemistry at the National Ignition Facility

None
Date: August 27, 2011
Creator: Eggert, J H
System: The UNT Digital Library
Heterogeneous Task Scheduling for Accelerated OpenMP (open access)

Heterogeneous Task Scheduling for Accelerated OpenMP

None
Date: September 27, 2011
Creator: Scogland, T W; Rountree, B; Feng, W & de Supinski, B R
System: The UNT Digital Library
Ab-initio description of the electonic stopping power beyond Boron-Oppenheimer approximation (open access)

Ab-initio description of the electonic stopping power beyond Boron-Oppenheimer approximation

None
Date: October 27, 2011
Creator: Schleife, A; Rinke, P; Bechstedt, F & de Walle, C
System: The UNT Digital Library
Electronic properties of the graphene/6H-SiC(0001̅ ) interface: A first-principles study (open access)

Electronic properties of the graphene/6H-SiC(0001̅ ) interface: A first-principles study

This article discusses electronic properties of the graphene/6H-SiC(0001̅) interface.
Date: July 27, 2011
Creator: Jayasekera, Thushari; Xu, Shu; Kim, Ki Wook & Buongiorno Nardelli, Marco
System: The UNT Digital Library