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Mobile Data Collection Applications: A Proof of Concept (open access)

Mobile Data Collection Applications: A Proof of Concept

This project's goal is to provide a proof of concept for mobile data collection applications, and identify the best ways such applications could be implemented and used. Such an application should decrease the time and resources users now need to devote to redundant data processes, and provide an easy of locating and retrieving data at a later time. The two types of available mobile devices, Personal Digital Assistants and Tablet Personal Computers, each have their particular strengths that suggest themselves for certain types of applications. As such, parallel data collection applications have been developed, with a common web application for uploading information to the database. While these aspects have been developed and proven, it still remains to refine these applications, develop the tables to hold their data, and field-test with users for their feedback.
Date: September 20, 2006
Creator: Chang, J.
System: The UNT Digital Library
Calculation of Radiative Corrections to Hyperfine Splitting in p1/2 States (open access)

Calculation of Radiative Corrections to Hyperfine Splitting in p1/2 States

Techniques to calculate one-loop radiative corrections to hyperfine splitting including binding corrections to all orders have been developed in the last decade for s states of atoms and ions. In this paper these methods are extended to p{sub 1/2} states for three cases. In the first case, the point-Coulomb 2p{sub 1/2} hyperfine splitting is treated for the hydrogen isoelectronic sequence, and the lowest order result, {alpha}/4{pi} E{sub F}, is shown to have large binding corrections at high Z. In the second case, neutral alkalis are considered. In the third case, hyperfine splitting of the 2p{sub 1/2} state of lithium-like bismuth is treated. In the latter two cases, correlation corrections are included and, in addition, the point is stressed that uncertainties associated with nuclear structure, which complicate comparison with experiment for s states, are considerably reduced because of the smaller overlap with the nucleus.
Date: September 20, 2006
Creator: Sapirstein, J & Cheng, K T
System: The UNT Digital Library
Pseudomonas aeruginosa forms Biofilms in Acute InfectionIndependent of Cell-to-Cell Signaling (open access)

Pseudomonas aeruginosa forms Biofilms in Acute InfectionIndependent of Cell-to-Cell Signaling

Biofilms are bacterial communities residing within a polysaccharide matrix that are associated with persistence and antibiotic resistance in chronic infections. We show that the opportunistic pathogen Pseudomonas aeruginosa forms biofilms within 8 hours of infection in thermally-injured mice, demonstrating that biofilms contribute to bacterial colonization in acute infections. P. aeruginosa biofilms were visualized within burned tissue surrounding blood vessels and adipose cells. Although quorum sensing (QS), a bacterial signaling mechanism, coordinates differentiation of biofilms in vitro, wild type and QS-deficient P. aeruginosa formed similar biofilms in vivo. Our findings demonstrate that P. aeruginosa forms biofilms on specific host tissues independent of QS.
Date: September 20, 2006
Creator: Schaber, J. Andy; Triffo, W. J.; Suh, Sang J.; Oliver, Jeffrey W.; Hastert, Mary C.; Griswold, John A. et al.
System: The UNT Digital Library
DESIGN OF A MICROFABRICATED, TWO-ELECTRODE PHASE-CONTRAST ELEMENTSUITABLE FOR ELECTRON MICROSCOPY (open access)

DESIGN OF A MICROFABRICATED, TWO-ELECTRODE PHASE-CONTRAST ELEMENTSUITABLE FOR ELECTRON MICROSCOPY

A miniature electrostatic element has been designed to selectively apply a ninety-degree phase shift to the unscattered beam in the back focal plane of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. The design involves a cylindrically shaped, biased-voltage electrode, which is surrounded by a concentric grounded electrode. Electrostatic calculations have been used to determine that the fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size is greater than 5:1. Unlike the planar, three-electrode einzel lens originally proposed by Boersch for the same purpose, this new design does not require insulating layers to separate the biased and grounded electrodes, and it can thus be produced by a very simple microfabrication process. Scanning electron microscope images confirm that mechanically robust devices with feature sizes of {approx}1 {micro}m can be easily fabricated. Preliminary experimental images demonstrate that these devices do apply a 90-degree phase shift between the scattered and unscattered electrons, as expected.
Date: September 20, 2006
Creator: Cambie, Rossana; Downing, Kenneth H.; Typke, Dieter; Glaeser,Robert M. & Jin, Jian
System: The UNT Digital Library
Coupling Magnetic Fields and ALE Hydrodynamics for 3D Simulations of MFCG's (open access)

Coupling Magnetic Fields and ALE Hydrodynamics for 3D Simulations of MFCG's

We review the development of a full 3D multiphysics code for the simulation of explosively driven Magnetic Flux Compression Generators (MFCG) and related pulse power devices. In a typical MFCG the device is seeded with an initial electric current and the device is then detonated. The detonation compresses the magnetic field and amplifies the current. This is a multiphysics problem in that detonation kinetics, electromagnetic diffusion and induction, material deformation, and thermal effects are all important. This is a tightly coupled problem in that the different physical quantities have comparable spatial and temporal variation, and hence should be solved simultaneously on the same computational mesh.
Date: September 20, 2006
Creator: White, D; Rieben, R & Wallin, B
System: The UNT Digital Library
Partial waves of baryon-antibaryon in three-body B mesondecay (open access)

Partial waves of baryon-antibaryon in three-body B mesondecay

The origin of the reversed angular correlation in thecontext of the pp-bar partial waves in the baryonic decay modes of Bmesons.
Date: September 20, 2006
Creator: Suzuki, Mahiko
System: The UNT Digital Library
METHOD FOR IN SITU VISUALIZATION OF TRITIUM DIFFUSED IN STAINLESS STEEL USING A DIGITAL AUTORADIOGRAPHIC IMAGING SYSTEM (open access)

METHOD FOR IN SITU VISUALIZATION OF TRITIUM DIFFUSED IN STAINLESS STEEL USING A DIGITAL AUTORADIOGRAPHIC IMAGING SYSTEM

At the end of their service lives, various stainless steel components of nuclear weapons that have been exposed to tritium gas are evaluated to determine the extent of the tritium permeation. This information is then used to assess the decrement to performance caused by hydrogen (tritium) embrittlement. This evaluation is currently performed using a photo-emulsion based method and requires 24 hours or longer to complete. A system based on digital imaging technology has recently been designed and built at the Savannah River National Laboratory that performs this evaluation in 10 minutes or less on typical samples.
Date: September 20, 2006
Creator: Gibbs, K & Carol Kestin, C
System: The UNT Digital Library
Ideal Laser Beam Propagation through high temperature ignition hohlraum plasmas (open access)

Ideal Laser Beam Propagation through high temperature ignition hohlraum plasmas

We demonstrate that a blue (3{omega}, 351 nm) laser beam with an intensity of 2 x 10{sup 15} W-cm{sup -2} propagates within the original beam cone through a 2-mm long, T{sub e}=3.5 keV high density (n{sub e} = 5 x 10{sup 20} cm{sup -3}) plasma. The beam produced less than 1% total backscatter; the resulting transmission is greater than 90%. Scaling of the electron temperature in the plasma shows that the plasma becomes transparent for uniform electron temperatures above 3 keV. These results are consistent with linear theory thresholds for both filamentation and backscatter instabilities inferred from detailed hydrodynamic simulations. This provides a strong justification for current inertial confinement fusion designs to remain below these thresholds.
Date: September 20, 2006
Creator: Froula, D H; Divol, L; Meezan, N; Dixit, S; Moody, J D; Pollock, B B et al.
System: The UNT Digital Library
An Extensible Business Process Approach for Managing Institutional Roles & Responsibilities ? A New Horizon for LLNL (open access)

An Extensible Business Process Approach for Managing Institutional Roles & Responsibilities ? A New Horizon for LLNL

None
Date: September 20, 2006
Creator: Aaron, C
System: The UNT Digital Library
Simulating Electron Clouds in High-Current Ion Accelerators withSolenoid Focusing (open access)

Simulating Electron Clouds in High-Current Ion Accelerators withSolenoid Focusing

Contamination from electrons is a concern for the solenoid-focused ion accelerators being developed for experiments in high-energy-density physics (HEDP). These electrons are produced directly by beam ions hitting lattice elements and intercepting diagnostics, or indirectly by ionization of desorbed neutral gas, and they are believed responsible for time dependence of the beam radius, emittance, and focal distance seen on the Solenoid Transport Experiment (STX) at Lawrence Berkeley National Laboratory. The electrostatic particle-in-cell code WARP has been upgraded to included the physics needed to simulate electron-cloud phenomena. We present preliminary self-consistent simulations of STX experiments suggesting that the observed time dependence of the beam stems from a complicated interaction of beam ions, desorbed neutrals, and electrons.
Date: September 20, 2006
Creator: Sharp, W. M.; Grote, D. P.; Cohen, R. H.; Friedman, A.; Vay, J. L.; Seidl, P. A. et al.
System: The UNT Digital Library
OVERVIEW OF TESTING TO SUPPORT PROCESSING OF SLUDGE BATCH 4 IN THE DEFENSE WASTE PROCESSING FACILITY (open access)

OVERVIEW OF TESTING TO SUPPORT PROCESSING OF SLUDGE BATCH 4 IN THE DEFENSE WASTE PROCESSING FACILITY

The Defense Waste Processing Facility (DWPF) at the Savannah River Site began processing of its third sludge batch in March 2004. To avoid a feed outage in the facility, the next sludge batch will have to be prepared and ready for transfer to the DWPF by the end of 2006. The next sludge batch, Sludge Batch 4 (SB4), will consist of a significant volume of HM-type sludge. HM-type sludge is very high in aluminum compared to the mostly Purex-type sludges that have been processed to date. The Savannah River National Laboratory (SRNL) has been working with Liquid Waste Operations to define the sludge preparation plans and to perform testing to support qualification and processing of SB4. Significant challenges have arisen during SB4 preparation and testing to include poor sludge settling behavior and lower than desired projected melt rates. An overview of the testing activities is provided.
Date: September 20, 2006
Creator: Herman, C
System: The UNT Digital Library