Improved Operation of the SSPX Spheromak (open access)

Improved Operation of the SSPX Spheromak

None
Date: August 18, 2005
Creator: Wood, R. D.; Hill, D. N.; Hooper, E. B.; Woodruff, S.; McLean, H. S. & Stallard, B. W.
Object Type: Article
System: The UNT Digital Library
Storage resource managers: Middleware components for gridstorage (open access)

Storage resource managers: Middleware components for gridstorage

The amount of scientific data generated by simulations orcollected from large scale experiments have reached levels that cannot bestored in the researcher's workstation or even in his/her local computercenter. Such data are vital to large scientific collaborations dispersedover wide-area networks. In the past, the concept of a Gridinfrastructure [1]mainly emphasized the computational aspect ofsupporting large distributed computational tasks, and optimizing the useof the network by using bandwidth reservation techniques. In this paperwe discuss the concept of Storage Resource Managers (SRMs) as componentsthat complement this with the support for the storage management of largedistributed datasets. The access to data is becoming the main bottleneckin such "data intensive" applications because the data cannot bereplicated in all sites. SRMs can be used to dynamically optimize the useof storage resource to help unclog this bottleneck.
Date: August 18, 2005
Creator: Shoshani, Arie; Sim, Alex & Gu, Junmin
Object Type: Report
System: The UNT Digital Library
The Pathogenomic Sequence Analysis of B. cereus and B. thuringiensis Isolates Closely Related to Bacillus anthracis (open access)

The Pathogenomic Sequence Analysis of B. cereus and B. thuringiensis Isolates Closely Related to Bacillus anthracis

The sequencing and analysis of two close relatives of Bacillus anthracis are reported. AFLP analysis of over 300 isolates of B.cereus, B. thuringiensis and B. anthracis identified two isolates as being very closely related to B. anthracis. One, a B. cereus, BcE33L, was isolated from a zebra carcass in Nambia; the second, a B. thuringiensis, 97-27, was isolated from a necrotic human wound. The B. cereus appears to be the closest anthracis relative sequenced to date. A core genome of over 3,900 genes was compiled for the Bacillus cereus group, including Banthracis. Comparative analysis of these two genomes with other members of the B. cereus group provides insight into the evolutionary relationships among these organisms. Evidence is presented that differential regulation modulates virulence, rather than simple acquisition of virulence factors. These genome sequences provide insight into the molecular mechanisms contributing to the host range and virulence of this group of organisms.
Date: August 18, 2005
Creator: Han, Cliff S.; Xie, Gary; Challacombe, Jean F.; Altherr, MichaelR.; Smriti, B.; Bruce, David et al.
Object Type: Article
System: The UNT Digital Library
From Sequential Extraction to Transport Modeling: Monitored Natural Attenuation as a Remediation Approach for Inorganic Contaminants (open access)

From Sequential Extraction to Transport Modeling: Monitored Natural Attenuation as a Remediation Approach for Inorganic Contaminants

To quantify metal natural attenuation processes in terms of environmental availability, sequential extraction experiments were carried out on subsurface soil samples impacted by a low pH, high sulfate, metals (Be, Ni, U, As) plume associated with the long-term operation of a coal plant at the Savannah River Site in South Carolina. Despite significant heterogeneity resulting both from natural and anthropogenic factors, sequential extraction results demonstrate that pH is a controlling factor in the prediction of the distribution of metal contaminants within the solid phases in soils at the site as well as the contaminant partitioning between the soil and the soil solution. Results for beryllium, the most mobile metal evaluated, exhibit increasing attenuation along the plume flow path which corresponds to an increasing plume pH. These laboratory- and field-scale studies provide mechanistic information regarding partitioning of metals to soils at the site (one of the major attenuation mechanisms for the metals at the field site). Subsequently, these data have been used in the definition of the contaminant source terms and contaminant transport factors in risk modeling for the site.
Date: August 18, 2005
Creator: Crapse, Kimberly P.; Serkiz, Steven M.; Pishko, Adrian L.; Kaplan, Daniel L.; Lee, Cindy M. & Schank, Anja
Object Type: Book
System: The UNT Digital Library
High Level Waste System Impacts from Small Column Ion Exchange Implementation (open access)

High Level Waste System Impacts from Small Column Ion Exchange Implementation

The objective of this task is to identify potential waste streams that could be treated with the Small Column Ion Exchange (SCIX) and perform an initial assessment of the impact of doing so on the High-Level Waste (HLW) system. Design of the SCIX system has been performed as a backup technology for decontamination of High-Level Waste (HLW) at the Savannah River Site (SRS). The SCIX consists of three modules which can be placed in risers inside underground HLW storage tanks. The pump and filter module and the ion exchange module are used to filter and decontaminate the aqueous tank wastes for disposition in Saltstone. The ion exchange module contains Crystalline Silicotitanate (CST in its engineered granular form is referred to as IONSIV{reg_sign} IE-911), and is selective for removal of cesium ions. After the IE-911 is loaded with Cs-137, it is removed and the column is refilled with a fresh batch. The grinder module is used to size-reduce the cesium-loaded IE-911 to make it compatible with the sludge vitrification system in the Defense Waste Processing Facility (DWPF). If installed at the SRS, this SCIX would need to operate within the current constraints of the larger HLW storage, retrieval, treatment, and disposal …
Date: August 18, 2005
Creator: McCabe, D. J.; Hamm, L. L.; Aleman, S. E.; Peeler, D. K.; Herman, C. C. & Edwards, T. B.
Object Type: Report
System: The UNT Digital Library
Using Decision Trees for Comparing Pattern Recognition Feature Sets (open access)

Using Decision Trees for Comparing Pattern Recognition Feature Sets

Determination of the best set of features has been acknowledged as one of the most difficult tasks in the pattern recognition process. In this report significance tests on the sort-ordered, sample-size normalized vote distribution of an ensemble of decision trees is introduced as a method of evaluating relative quality of feature sets. Alternative functional forms for feature sets are also examined. Associated standard deviations provide the means to evaluate the effect of the number of folds, the number of classifiers per fold, and the sample size on the resulting classifications. The method is applied to a problem for which a significant portion of the training set cannot be classified unambiguously.
Date: August 18, 2005
Creator: Proctor, D D
Object Type: Article
System: The UNT Digital Library
Laboratory astrophysics and atomic physics using the NASA/GSFC microcalorimeter spectrometers at the LLNL Electron Beam Ion Trap and Radiation Properties Facility (open access)

Laboratory astrophysics and atomic physics using the NASA/GSFC microcalorimeter spectrometers at the LLNL Electron Beam Ion Trap and Radiation Properties Facility

The 32 pixel laboratory microcalorimeter spectrometer built by the NASA/Goddard Space Flight Center is now an integral part of the spectroscopy suite used routinely by the electron beam ion trap and radiative properties group at the Lawrence Livermore National Laboratory. The second generation laboratory instrument, dubbed the XRS/EBIT, is nearly identical to the XRS instrument on the Suzaku X-ray Observatory, formerly Astro-E2. The detector array is from the same processed wafer and uses the same HgTe absorbers. it is being used to measure the photon emission from a variety of radiation sources. These include x-ray emission from laboratory simulated celestial sources, x-ray emission from highly charged ions of Au, and x-ray emission following charge exchange and radiative electron capture. The wide range of applications demonstrates the versatility of a high-resolution, high-efficiency low temperature detector that is able to collect data continually with minimal operator servicing.
Date: August 18, 2005
Creator: Brown, G.; Beiersdorfer, P.; Boyce, K.; Chen, H.; Gu, M. F.; Kahn, S. et al.
Object Type: Article
System: The UNT Digital Library
Magnetohydrodynamic Turbulence Simulations on the Earth SimulatorUsing the Lattice Boltzmann Method (open access)

Magnetohydrodynamic Turbulence Simulations on the Earth SimulatorUsing the Lattice Boltzmann Method

None
Date: August 18, 2005
Creator: Carter, Jonathan; Soe, Min; Oliker, Leonid; Tsuda, Yoshinori; Vahala, George; Vahala, Linda et al.
Object Type: Article
System: The UNT Digital Library
CORROSION RELIABILITY PREDICTION: LONG TERM NUCLEAR WASTE STORAGE IN YUCCA MOUNTAIN (open access)

CORROSION RELIABILITY PREDICTION: LONG TERM NUCLEAR WASTE STORAGE IN YUCCA MOUNTAIN

The US. Department of Energy has proposed the disposal of high level nuclear waste from commercial and defense reactors in a mined geologic repository under Yucca Mountain, Nevada. The waste will be stored in metallic canisters. The barrier against corrosion will be an Alloy 22 canister and a Ti Grade 7 drip shield. Both of these materials are extremely corrosion resistant. The environment inside Yucca Mountain is relatively benign, but the long time period over which these materials must resist penetration makes corrosion a concern. This paper presents a background of the corrosion issues and shows some recent results regarding measurements of localized corrosion under thin aqueous layers and layers that simulate wet dust deposits.
Date: August 18, 2005
Creator: Frankel, G.S.; Tada, E. & Maier, B.
Object Type: Report
System: The UNT Digital Library
SAFETY STUDIES TO MEASURE EXOTHERMIC REACTIONS OF SPENT PLUTONIUM DECONTAMINATION CHEMICALS USING WET & DRY DECONTAMINATION METHODS (open access)

SAFETY STUDIES TO MEASURE EXOTHERMIC REACTIONS OF SPENT PLUTONIUM DECONTAMINATION CHEMICALS USING WET & DRY DECONTAMINATION METHODS

None
Date: August 18, 2005
Creator: HOPKINS, A.M.; JACKSON, G.W.; MINETTE, M.; EWALT, J.; COOPER, T.; SCOTT, P. et al.
Object Type: Article
System: The UNT Digital Library
MATERIAL QUALITY CHARACTERIZATION OF CDZNTE SUBSTRATES FOR HGCDTE EPITAXY. (open access)

MATERIAL QUALITY CHARACTERIZATION OF CDZNTE SUBSTRATES FOR HGCDTE EPITAXY.

CdZnTe (CZT) has been traditionally used as substrate for HgCdTe (MCT) epitaxy. The constraint of good lattice matching plays a fundamental role in the use of this substrate. In, fact, despite the difficulties in growing large area of affordable high-quality substrates, CZT wafers remain the best choice for high yield infrared devices. Nevertheless, material quality of the substrate and epilayer play a limiting role in IR focal plane array (FPA) detector technology. Furthermore, data suggest that the quality of the epilayer is affected by imperfections in the CZT substrate. In addition the pixel size for the current generation of FPAs (less than 20 {micro}m) suggests a need for detailed microscale characterization and an understanding of the substrates and epilayers on at least the spatial scale of the pixel dimensions. In an effort to understand the correlation between material quality and device performances, we have begun to study CZT substrates to investigate bulk and surface properties. The National Synchrotron Light Source (NSLS, BNL) permits a wide variety of material investigations that take advantage of the highly collimated photon radiation emitted from the X-ray and VUV-IR rings. Synchrotron radiation offers the capability to combine good resolution and shorter exposure times than conventional …
Date: August 18, 2005
Creator: Carini, G. A.; Bolotnikov, A. E.; Camarda, G. S.; James, R. B. & AL., ET
Object Type: Article
System: The UNT Digital Library
Confidence Probability versus Detection Probability (open access)

Confidence Probability versus Detection Probability

In a discovery sampling activity the auditor seeks to vet an inventory by measuring (or inspecting) a random sample of items from the inventory. When the auditor finds every sample item in compliance, he must then make a confidence statement about the whole inventory. For example, the auditor might say: ''We believe that this inventory of 100 items contains no more than 5 defectives with 95% confidence.'' Note this is a retrospective statement in that it asserts something about the inventory after the sample was selected and measured. Contrast this to the prospective statement: ''We will detect the existence of more than 5 defective items in this inventory with 95% probability.'' The former uses confidence probability while the latter uses detection probability. For a given sample size, the two probabilities need not be equal, indeed they could differ significantly. Both these probabilities critically depend on the auditor's prior belief about the number of defectives in the inventory and how he defines non-compliance. In other words, the answer strongly depends on how the question is framed.
Date: August 18, 2005
Creator: Axelrod, M
Object Type: Report
System: The UNT Digital Library
The Piece Wise Linear Reactive Flow Model (open access)

The Piece Wise Linear Reactive Flow Model

For non-ideal explosives a wide range of behavior is observed in experiments dealing with differing sizes and geometries. A predictive detonation model must be able to reproduce many phenomena including such effects as: variations in the detonation velocity with the radial diameter of rate sticks; slowing of the detonation velocity around gentle corners; production of dead zones for abrupt corner turning; failure of small diameter rate sticks; and failure for rate sticks with sufficiently wide cracks. Most models have been developed to explain one effect at a time. Often, changes are made in the input parameters used to fit each succeeding case with the implication that this is sufficient for the model to be valid over differing regimes. We feel that it is important to develop a model that is able to fit experiments with one set of parameters. To address this we are creating a new generation of models that are able to produce better fitting to individual data sets than prior models and to simultaneous fit distinctly different regimes of experiments. Presented here are details of our new Piece Wise Linear reactive flow model applied to LX-17.
Date: August 18, 2005
Creator: Vitello, P & Souers, P C
Object Type: Article
System: The UNT Digital Library
Using Ancillary Information to Reduce Sample Size in Discovery Sampling and the Effects of Measurement Error (open access)

Using Ancillary Information to Reduce Sample Size in Discovery Sampling and the Effects of Measurement Error

Discovery sampling is a tool used in a discovery auditing. The purpose of such an audit is to provide evidence that some (usually large) inventory of items complies with a defined set of criteria by inspecting (or measuring) a representative sample drawn from the inventory. If any of the items in the sample fail compliance (defective items), then the audit has discovered an impropriety, which often triggers some action. However finding defective items in a sample is an unusual event--auditors expect the inventory to be in compliance because they come to the audit with an ''innocent until proven guilty attitude''. As part of their work product, the auditors must provide a confidence statement about compliance level of the inventory. Clearly the more items they inspect, the greater their confidence, but more inspection means more cost. Audit costs can be purely economic, but in some cases, the cost is political because more inspection means more intrusion, which communicates an attitude of distrust. Thus, auditors have every incentive to minimize the number of items in the sample. Indeed, in some cases the sample size can be specifically limited by a prior agreement or an ongoing policy. Statements of confidence about the results …
Date: August 18, 2005
Creator: Axelrod, M
Object Type: Report
System: The UNT Digital Library
Special Analysis: Atmospheric Dose Resulting from the Release of C14 from Reactor Moderator Deionizers in a Disposal Environment (open access)

Special Analysis: Atmospheric Dose Resulting from the Release of C14 from Reactor Moderator Deionizers in a Disposal Environment

The proposed action of disposing of 52 moderator deionizer vessels within the ILV was evaluated in this SA. In particular, a detailed analysis of the release of {sup 14}C via the atmospheric pathway was conducted for these vessels since the major concern has been the nearly 20 Ci of {sup 14}C that is associated with each vessel. The more rigorous evaluation of the atmospheric pathway for {sup 14}C included incorporation of new information about the chemical availability of {sup 14}C when disposed in a grout/cement encapsulation environment, as will be the case in the ILV. This information was utilized to establish the source term for a 1-D numerical model to simulate the diffusion of {sup 14}CO{sub 2} from the ILV Waste Zone to the land surface. The results indicate a peak surface emanation rate from the entire ILV of 1.42E-08 Ci/yr with an associated dose of only 3.83E-05 mrem/yr to the Maximally Exposed Individual (MEI) at 100m. The fact that the atmospheric pathway exposure for {sup 14}C is controlled by chemical solubility limits for {sup 14}C between the solid waste, pore water and pore vapor within the disposal environment rather than the absolute inventory suggests that the establishment of specific …
Date: August 18, 2005
Creator: Hiergesell, Robert A. & Swingle, Robert F.
Object Type: Report
System: The UNT Digital Library
Collider Phenomenology of Higgs Bosons in Left-RightSymmetric Randall-Sundrum Models (open access)

Collider Phenomenology of Higgs Bosons in Left-RightSymmetric Randall-Sundrum Models

We study the corrections to Higgs physics in a model of a single warped extra dimension with all fields except the Higgs in the bulk, and a gauge symmetry extended to SU(2){sub L} x SU(2){sub R} x U(1){sub B-L}. We find that generically the Higgs coupling to electroweak gauge boson pairs is suppressed, the coupling to gluons is enhanced, and the coupling to photons is often suppressed, but can be enhanced.
Date: August 18, 2005
Creator: Lillie, B.
Object Type: Article
System: The UNT Digital Library
Helium Pot System for Maintaining Sample Temperature after Cryocooler Deactivation (open access)

Helium Pot System for Maintaining Sample Temperature after Cryocooler Deactivation

None
Date: August 18, 2005
Creator: Haid, B J
Object Type: Article
System: The UNT Digital Library
Simulation of Positronium: Toward More Realistic Models of Void Spaces in Materials (open access)

Simulation of Positronium: Toward More Realistic Models of Void Spaces in Materials

An exact treatment of the positron and electron in a two-chain, Path Integral Monte Carlo (PIMC) simulation is used to calculate both self-annihilation and pickoff rates at finite temperature. It has already been demonstrated that this technique can reproduce and extend results of simple theories of positrons and positronium (Ps) in spherical voids. Here, we include the effect of the linear dielectric response of a homogeneous material on the annihilation rate of positrons and Ps. In addition, we find lifetimes and structural information for Ps in cylindrical channels, both with and without adsorbed fluid atoms.
Date: August 18, 2005
Creator: Bug, A; Cronin, T; Sterne, P & Wolfson, Z
Object Type: Article
System: The UNT Digital Library
Full Detector Simulation Using SLIC and LCDD (open access)

Full Detector Simulation Using SLIC and LCDD

Simulator for the Linear Collider (SLIC) and Linear Collider Detector Description (LCDD) provide a flexible and powerful package for full detector simulations. This paper outlines the main features of SLIC and LCDD and explains the structure of an LCDD document used for detector description input.
Date: August 18, 2005
Creator: McCormick, J.
Object Type: Article
System: The UNT Digital Library