Dosimetry Modeling for Predicting Radiolytic Production at the Spent Fuel - Water Interface (open access)

Dosimetry Modeling for Predicting Radiolytic Production at the Spent Fuel - Water Interface

Modeling of the alpha, beta, and gamma dose from spent fuel as a function of particle size and fuel to water ratio was examined. These doses will be combined with modeling of G values and interactions to determine the concentration of various species formed at the fuel water interface and their affect on dissolution rates.
Date: April 30, 2006
Creator: Miller, William H.; Kline, Amanda J. & Hanson, Brady D.
System: The UNT Digital Library
2005 Plant Metabolic Engineering Gordon Conference - July 10-15, 2005 (open access)

2005 Plant Metabolic Engineering Gordon Conference - July 10-15, 2005

The post-genomic era presents new opportunities for manipulating plant chemistry for improvement of plant traits such as disease and stress resistance and nutritional qualities. This conference will provide a setting for developing multidisciplinary collaborations needed to unravel the dynamic complexity of plant metabolic networks and advance basic and applied research in plant metabolic engineering. The conference will integrate recent advances in genomics, with metabolite and gene expression analyses. Research discussions will explore how biosynthetic pathways interact with regard to substrate competition and channeling, plasticity of biosynthetic enzymes, and investigate the localization, structure, and assembly of biosynthetic metabolons in native and nonnative environments. The meeting will develop new perspectives for plant transgenic research with regard to how transgene expression may influence cellular metabolism. Incorporation of spectroscopic approaches for metabolic profiling and flux analysis combined with mathematical modeling will contribute to the development of rational metabolic engineering strategies and lead to the development of new tools to assess temporal and subcellular changes in metabolite pools. The conference will also highlight new technologies for pathway engineering, including use of heterologous systems, directed enzyme evolution, engineering of transcription factors and application of molecular/genetic techniques for controlling biosynthetic pathways.
Date: June 30, 2006
Creator: Wurtzel, Eleanore T.
System: The UNT Digital Library
Amplitude Dependence of Time of Flight. (open access)

Amplitude Dependence of Time of Flight.

Machida found in tracking studies [Shinji Machida, presentation at the FFAG05 Workshop, Kyoto University Research Reactor Institute, Osaka, Japan, 5-9 December 2005] that the time of flight in a linear non-scaling FFAG depended on the transverse amplitude of the particles. I compute a relationship between the transverse amplitude dependence of the time of flight and the variation of tune with energy and explain its physical origin.
Date: January 30, 2006
Creator: Berg, J. S.
System: The UNT Digital Library
Summary of the FFAG05 Workshop at KEK (open access)

Summary of the FFAG05 Workshop at KEK

The FFAG05 workshop at KEK is one in a series of important annual gatherings of scientists working in the area of fixed field alternating gradient accelerators (FFAGs). At this workshop, we heard of many FFAG designs that are in operation, under construction, and in the planning stages. These machines are being used for a wide variety of applications. We also had a great deal of discussion of some of the theoretical aspects of FFAG design. This paper attempts to give a coherent summary of the workshop, and hopefully serves as an introduction to the more detailed papers in the workshop proceedings.
Date: January 30, 2006
Creator: Berg, J. S.
System: The UNT Digital Library
Update on electron-cloud power deposition for the LHC arcdipoles (open access)

Update on electron-cloud power deposition for the LHC arcdipoles

We revisit the estimation of the power deposited by the electron cloud (EC) in the arc dipoles of the LHC by means of simulations. We adopt, as simulation input, a set of electron-related parameters closely resembling those used in recent simulations at CERN [1]. We explore values for the bunch population Nb in the range 0.4 x 10^11 <= Nb <=1.6 x 10^11, peak secondary electron yield (SEY) delta max in the range 1.0 <= delta max <= 2.0, and bunch spacing tb either 25 or 75 ns. For tb=25 ns we find that the EC average power deposition per unit length of beam pipe, dPbar/dz, will exceed the available cooling capacity, which we take to be 1.7 W/m at nominal Nb [2], if delta max exceeds ~1.3, but dPbar/dz will be comfortably within the cooling capacity if delta max <= 1.2. For tb =75 ns dPbar/dz exceeds the cooling capacity only when delta max > 2 and Nb > 1.5 x 10^11 taken in combination. The rediffused component of the secondary electron emission spectrum plays a significant role: if we artificially suppress this component while keeping delta max fixed, dPbar/dz is roughly cut in half for most values of …
Date: January 30, 2006
Creator: Furman, Miguel A. & Chaplin, Vernon H.
System: The UNT Digital Library
METHODS TO CALCULATE CORROSION RATES FOR ALLOY 22 FROM POLARIZATION RESISTANCE EXPERIMENTS (open access)

METHODS TO CALCULATE CORROSION RATES FOR ALLOY 22 FROM POLARIZATION RESISTANCE EXPERIMENTS

None
Date: April 30, 2006
Creator: L. L. Wong, S. I. Martin, R. B. Rebak
System: The UNT Digital Library
OVERVIEW OF MODELING APPROACHES FOR ASSESSING NATURAL SYSTEM PERFORMANCE OF THE HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY AT YUCCA MOUNTAIN, NEVADA (open access)

OVERVIEW OF MODELING APPROACHES FOR ASSESSING NATURAL SYSTEM PERFORMANCE OF THE HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY AT YUCCA MOUNTAIN, NEVADA

For two decades, extensive hydrologic investigations have been conducted for geologic disposal of high-level radioactive waste in fractured volcanic tuffs at Yucca Mountain, Nevada. Extensive field and laboratory geologic, hydrologic, and geochemical testing has provided a large amount of data for developing the conceptual understanding of these processes and parameters for quantifying these processes. A suite of sophisticated numerical models has been developed to assess the long-term performance of the natural barrier of unsaturated zone (UZ) and saturated zone (SZ) to flow of groundwater and transport of radionuclides released from the repository. This work focuses on characterizing surface and subsurface processes of climate change, infiltration, percolation in the UZ and groundwater flow in the SZ, as well as on predicting hydrologic responses of the natural system to the emplacement of waste packages in drifts, including seepage of water into emplacement drifts and radionuclide transport in the UZ and SZ. These models are then abstracted into a total system performance assessment (TSPA) model. The TSPA integrates these natural attributes with features of engineered systems, and through systematic stochastic analyses involving Monte Carlo simulations, predicts the dose consequences and groundwater concentrations for at least 10,000 years for various future climate conditions, waste …
Date: May 30, 2006
Creator: Zhu, M.
System: The UNT Digital Library
Measurements of Gamma in BaBar (open access)

Measurements of Gamma in BaBar

We report on the first measurements to the angle {gamma} of the Unitarity Triangle in B meson decays collected by the BABAR detector at the SLAC PEP-II asymmetric-energy B factory in the years 1999-2004.
Date: August 30, 2006
Creator: Marchiori, G.
System: The UNT Digital Library
Trace-level beryllium analysis in the laboratory and in the field: State of the art, challenges, and opportunities (open access)

Trace-level beryllium analysis in the laboratory and in the field: State of the art, challenges, and opportunities

Control of workplace exposure to beryllium is a growing issue in the United States and other nations. As the health risks associated with low-level exposure to beryllium are better understood, the need increases for improved analytical techniques both in the laboratory and in the field. These techniques also require a greater degree of standardization to permit reliable comparison of data obtained from different locations and at different times. Analysis of low-level beryllium samples, in the form of air filters or surface wipes, is frequently required for workplace monitoring or to provide data to support decision-making on implementation of exposure controls. In the United States and the United Kingdom, the current permissible exposure level is 2 {micro}g/m{sup 3} (air), and the United States Department of Energy has implemented an action level of 0.2 {micro}g/m{sup 3} (air) and 0.2 {micro}g/100 cm{sup 2} (surface). These low-level samples present a number of analytical challenges, including (1) a lack of suitable standard reference materials, (2) unknown robustness of sample preparation techniques, (3) interferences during analysis, (4) sensitivity (sufficiently low detection limits), (5) specificity (beryllium speciation), and (6) data comparability among laboratories. Additionally, there is a need for portable, real-time (or near real-time) equipment for beryllium …
Date: March 30, 2006
Creator: BRISSON, MICHAEL
System: The UNT Digital Library
Mislocalization of the Drosophila centromere-specific histone CIDpromotes formation of functional ectopic kinetochores (open access)

Mislocalization of the Drosophila centromere-specific histone CIDpromotes formation of functional ectopic kinetochores

The centromere-specific histone variant CENP-A (CID in Drosophila) is a structural and functional foundation for kinetochore formation and chromosome segregation. Here, we show that overexpressed CID is mislocalized into normally non-centromeric regions in Drosophila tissue culture cells and animals. Analysis of mitoses in living and fixed cells reveals that mitotic delays, anaphase bridges, chromosome fragmentation, and cell and organismal lethality are all direct consequences of CID mislocalization. In addition, proteins that are normally restricted to endogenous kinetochores assemble at a subset of ectopic CID incorporation regions. The presence of microtubule motors and binding proteins, spindle attachments, and aberrant chromosome morphologies demonstrate that these ectopic kinetochores are functional. We conclude that CID mislocalization promotes formation of ectopic centromeres and multicentric chromosomes, which causes chromosome missegregation, aneuploidy, and growth defects. Thus, CENP-A mislocalization is one possible mechanism for genome instability during cancer progression, as well as centromere plasticity during evolution.
Date: January 30, 2006
Creator: Heun, Patrick; Erhardt, Sylvia; Blower, Michael D.; Weiss,Samara; Skora, Andrew D. & Karpen, Gary H.
System: The UNT Digital Library
D0-Anti-D0 Mixing Results From BaBar By Analysis of D0 ---> K+ Pi- Pi0 Dalitz-Plot Regions (open access)

D0-Anti-D0 Mixing Results From BaBar By Analysis of D0 ---> K+ Pi- Pi0 Dalitz-Plot Regions

We present a preliminary search for D{sup 0}-{bar D}{sup 0} mixing using the decays D{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0}, additionally presenting Dalitz-plot distributions and a measurement of the branching ratio for this mode. A new tagging technique is used to produce the doubly Cabibbo-suppressed Dalitz plot, which in turn is used to motivate the method used for the D-mixing search. We analyze 230.4 fb{sup -1} of data collected from the BABAR detector at the PEP-II collider. Assuming CP conservation, we find R{sub M} &lt; 0.054% with 95% confidence, and we estimate that the data are consistent with no mixing at a 4.5% confidence level. We present D-mixing results both with and without the assumption of CP conservation.
Date: June 30, 2006
Creator: Wilson, Michael G.
System: The UNT Digital Library
GAS PHASE MOLECULAR DYNAMICS: HIGH-RESOLUTION SPECTROSCOPIC PROBES OF CHEMICAL DYNAMICS. (open access)

GAS PHASE MOLECULAR DYNAMICS: HIGH-RESOLUTION SPECTROSCOPIC PROBES OF CHEMICAL DYNAMICS.

This research is carried out as part of the Gas Phase Molecular Dynamics group program in the Chemistry Department at Brookhaven National Laboratory. High-resolution spectroscopic tools are developed and applied to problems in chemical dynamics. Recent topics have included the state-resolved studies of collision-induced electronic energy transfer, dynamics of barrierless unimolecular reactions, and the kinetics and spectroscopy of transient species.
Date: May 30, 2006
Creator: Hall, G. E.
System: The UNT Digital Library
PROGRESS WITH K BASINS SLUDGE RETRIEVAL STABILIZATION & PACKAGING AT THE HANFORD NUCLEAR SITE (open access)

PROGRESS WITH K BASINS SLUDGE RETRIEVAL STABILIZATION & PACKAGING AT THE HANFORD NUCLEAR SITE

This paper shows how Fluor Hanford and BNG America have combined nuclear plant skills from the U.S. and the U.K. to devise methods to retrieve and treat the sludge that has accumulated in K Basins at the Hanford Site over many years. Retrieving the sludge is the final stage in removing fuel and sludge from the basins to allow them to be decontaminated and decommissioned, so as to remove the threat of contamination of the Columbia River. A description is given of sludge retrieval using vacuum lances and specially developed nozzles and pumps into Consolidation Containers within the basins. The special attention that had to be paid to the heat generation and potential criticality issues with the irradiated uranium-containing sludge is described. The processes developed to re-mobilize the sludge from the Consolidation Containers and pump it through flexible and transportable hose-in-hose piping to the treatment facility are explained with particular note made of dealing with the abrasive nature of the sludge. The treatment facility, housed in an existing Hanford building, is described, and the uranium-corrosion and grout packaging processes explained. The uranium corrosion process is a robust, tempered process very suitable for dealing with a range of differing sludge compositions. …
Date: January 30, 2006
Creator: KNOLLMEYER, P.M.; PHILLIPS, C & TOWNSON, P.S.
System: The UNT Digital Library
Hanford Site River Protection Project (RPP) Tank Farm Closure (open access)

Hanford Site River Protection Project (RPP) Tank Farm Closure

The U. S. Department of Energy, Office of River Protection and the CH2M HILL Hanford Group, Inc. are responsible for the operations, cleanup, and closure activities at the Hanford Tank Farms. There are 177 tanks overall in the tank farms, 149 single-shell tanks (see Figure 1), and 28 double-shell tanks (see Figure 2). The single-shell tanks were constructed 40 to 60 years ago and all have exceeded their design life. The single-shell tanks do not meet Resource Conservation and Recovery Act of 1976 [1] requirements. Accordingly, radioactive waste is being retrieved from the single-shell tanks and transferred to double-shell tanks for storage prior to treatment through vitrification and disposal. Following retrieval of as much waste as is technically possible from the single-shell tanks, the Office of River Protection plans to close the single-shell tanks in accordance with the Hanford Federal Facility Agreement and Consent Order [2] and the Atomic Energy Act of 1954 [3] requirements. The double-shell tanks will remain in operation through much of the cleanup mission until sufficient waste has been treated such that the Office of River Protection can commence closing the double-shell tanks. At the current time, however, the focus is on retrieving waste and closing …
Date: January 30, 2006
Creator: Jaraysi, M. N.; Smith, Z.; Quintero, R.; Burandt, M. B. & Hewitt, W.
System: The UNT Digital Library
EXPERIENCE USING PHENOMENA IDENTIFICATION AND RANKING TECHNIQUE (PIRT) FOR NUCLEAR ANALYSIS. (open access)

EXPERIENCE USING PHENOMENA IDENTIFICATION AND RANKING TECHNIQUE (PIRT) FOR NUCLEAR ANALYSIS.

THE PHENOMENA IDENTIFICATION AND RANKING TECHNIQUE (PIRT) IS A SYSTEMATIC WAY OF GATHERING INFORMATION FROM EXPERTS ON A SPECIFIC SUBJECT, AND RANKING THE IMPORTANCE OF THE INFORMATION, IN ORDER TO MEET SOME DECISION MAKING OBJECTIVE. IT HAS BEEN APPLIED TO MANY NUCLEAR TECHONLOGY ISSUES INCLUDING NUCLEAR ANALYSIS IN ORDER TO HELP GUIDE RESEARCH OR DEVELOP REGULATORY REQUIREMENTS.
Date: June 30, 2006
Creator: DIAMOND, DAVID J.
System: The UNT Digital Library
HDF5-FastQuery: Accelerating Complex Queries on HDF Datasets usingFast Bitmap Indices (open access)

HDF5-FastQuery: Accelerating Complex Queries on HDF Datasets usingFast Bitmap Indices

Large scale scientific data is often stored in scientific data formats such as FITS, netCDF and HDF. These storage formats are of particular interest to the scientific user community since they provide multi-dimensional storage and retrieval. However, one of the drawbacks of these storage formats is that they do not support semantic indexing which is important for interactive data analysis where scientists look for features of interests such as ''Find all supernova explosions where energy &gt; 10{sup 5} and temperature &gt; 10{sup 6}''. In this paper we present a novel approach called HDF5-FastQuery to accelerate the data access of large HDF5 files by introducing multi-dimensional semantic indexing. Our implementation leverages an efficient indexing technology called bitmap indexing that has been widely used in the database community. Bitmap indices are especially well suited for interactive exploration of large-scale read only data. Storing the bitmap indices into the HDF5 file has the following advantages: (a) Significant performance speedup of accessing subsets of multi-dimensional data and (b) portability of the indices across multiple computer platforms. We will present an API that simplifies the execution of queries on HDF5 files for general scientific applications and data analysis. The design is flexible enough to accommodate …
Date: March 30, 2006
Creator: Gosink, Luke; Shalf, John; Stockinger, Kurt; Wu, Kesheng & Bethel,Wes
System: The UNT Digital Library
Field Ionization of Neutral Litium Vapor Using a 28.5 GeV Electron Beam (open access)

Field Ionization of Neutral Litium Vapor Using a 28.5 GeV Electron Beam

The E164/E164X plasma wakefield experiment studies beam-plasma interactions at the Stanford Linear Acceleration Center (SLAC). Due to SLAC's recent ability to variably compress bunches longitudinally from 650 {micro}m down to 20 {micro}m, the incoming beam is sufficiently dense to field ionize the neutral lithium (Li) vapor. The field ionization effects are characterized by the beams energy loss through the Li vapor column. Experiment results are presented.
Date: January 30, 2006
Creator: O'Connell, C. L.; Barnes, C. D.; Decker, F. J.; Hogan, M. J.; Iverson, R.; Krejcik, P. et al.
System: The UNT Digital Library
Effect of Crevice Former on Corrosion Damage Propagation (open access)

Effect of Crevice Former on Corrosion Damage Propagation

None
Date: January 30, 2006
Creator: J. H. Payer, U. Landau, X. Shan, A. S. Agarwal
System: The UNT Digital Library
THE WEAK MIXING ANGLE AND NEW PHYSICS (A TALE OF TWO NUMBERS) (open access)

THE WEAK MIXING ANGLE AND NEW PHYSICS (A TALE OF TWO NUMBERS)

The two best Z pole determinations of sin{sup 2} {theta}{sub W} (m{sub z}){sub {ovr MS}} differ by 3 sigma, a feature lost in global fits and averaging. Individually, sin{sup 2} {theta}{sub W}(m{sub Z}){sub {ovr MS}} = 0.2307(3) obtained from A{sub LR}, taken together with m{sub W} = 80.410(32) GeV, points to a very light Higgs boson, m{sub H} {approx_equal} 12-63 GeV, already ruled out experimentally. it is, however, easily redeemed by low mass scale supersymmetry or models with (effectively) S {approx_equal} -0.12 and T {approx_equal} +0.06. Alternatively, sin{sup 2} {theta}{sub W} (m{sub Z}){sub {ovr MS}} {approx_equal} 0.2320(3) obtained from A{sub FB}(Z {yields} {ovr bb}), suggests a very heavy Higgs, m{sub H} {approx} 500 GeV, along with S {approx_equal} +0.45 which is suggestive of Technicolor models. Future ways to resolve this discrepancy are briefly discussed.
Date: May 30, 2006
Creator: MARCIANO, W.
System: The UNT Digital Library
The International Linear Collider Beam Dumps (open access)

The International Linear Collider Beam Dumps

The ILC beam dumps are a key part of the accelerator design. At Snowmass 2005, the current status of the beam dump designs was reviewed, and the options for the overall dump layout considered. This paper describes the available dump options for the baseline and the alternatives and considers issues for the dumps that require resolution.
Date: January 30, 2006
Creator: Appleby, R.; Keller, L.; Markiewicz, T.; Seryi, A.; Walz, D. & Sugahara, R.
System: The UNT Digital Library
COUPLED MULTI-ELECTRODE INVESTIGATION OF CREVICE CORROSION OF 316 STAINLESS STEEL (open access)

COUPLED MULTI-ELECTRODE INVESTIGATION OF CREVICE CORROSION OF 316 STAINLESS STEEL

Crevice corrosion is currently studied using either one of two techniques depending on the data needed. The first method is a multi-crevice former over a metallic sample; this provides information on the severity of crevice corrosion (depth, position, frequency) but delivers little to no electrochemical information [1]. The second method involves the potentiodynamic or potentiostatic study of an uncreviced sample in model crevice solution or under a crevice former in aggressive solution [2]. Crevice corrosion is highly dependent on the position in the crevice. The distance from the crevice mouth will affect the depth of attack, the solution composition and pH, and the ohmic drop and the true potential in the crevice [3-6]. These in turn affect the current density as a function of potential and position. A Multi-Channel Micro-Electrode Analyzer (MMA) has been recently used to demonstrate the interaction between localized corrosion sites (pitting corrosion and intergranular corrosion) [7]. MMA can provide spatial resolution of electrochemical properties in the crevice. By coupling such a tool with scaling laws derived from experimental data (a simple equation linking the depth of crevice corrosion initiation to the crevice gap), it is possible to produce highly instrumented crevices, rescaled to enable spatial resolution …
Date: January 30, 2006
Creator: Scully, F. Bocher and J. R.
System: The UNT Digital Library
Test Bed for Superconducting Materials (open access)

Test Bed for Superconducting Materials

Superconducting rf cavities are increasingly used in accelerators. Gradient is a parameter of particular importance for the ILC. Much progress in gradient has been made over the past decade, overcoming problems of multipacting, field emission, and breakdown triggered by surface impurities. However, the quenching limit of the surface magnetic field for niobium remains a hard limitation on cavity fields sustainable with this technology. Further exploration of materials and preparation may offer a path to surpassing the current limit. For this purpose, we have designed a resonant test cavity. One wall of the cavity is formed by a flat sample of superconducting material; the rest of the cavity is copper or niobium. The H field on the sample wall is 75% higher than on any other surface. Multipacting is avoided by use of a mode with no surface electric field. The cavity will be resonated through a coupling iris with high-power rf at superconducting temperature until the sample wall quenches, as detected by a change in the quality factor. This experiment will allow us to measure critical magnetic fields up to well above that of niobium with minimal cost and effort.
Date: January 30, 2006
Creator: Nantista, C
System: The UNT Digital Library
Plasma Dark Current in Self-Ionized Plasma Wakefield Accelerators (open access)

Plasma Dark Current in Self-Ionized Plasma Wakefield Accelerators

Evidence of particle trapping has been observed in a beam driven Plasma Wake Field Accelerator (PWFA) experiment, E164X, conducted at the Stanford Linear Accelerator Center by a collaboration which includes USC, UCLA and SLAC. Such trapping produces plasma dark current when the wakefield amplitude is above a threshold value and may place a limit on the maximum acceleration gradient in a PWFA. Trapping and dark current are enhanced when in an ionizing plasma, that is self-ionized by the beam. Here we present experimental results.
Date: January 30, 2006
Creator: Oz, E.; Deng, S.; Katsouleas, T.; Muggli, P.; U., /Southern California; Iverson, R. et al.
System: The UNT Digital Library
RF and Magnetic Measurements on the SPARC Photoinjector and Solenoid at UCLA (open access)

RF and Magnetic Measurements on the SPARC Photoinjector and Solenoid at UCLA

The rf photocathode gun and the solenoid for the SPARC project at INFN-LNF (Frascati) have been fabricated and undergone initial testing at UCLA. The advanced aspects of the design of these devices are detailed. Final diagnosis of the tuning of the RF gun performance, including operating mode frequency and field balance, is described. The emittance compensating solenoid magnet, which is designed to be tuned in longitudinal position by differential excitation of the coils, has been measured using Hall probe scans for field profiling, and pulsed wire methods to determine the field center. Comparisons between measurements and the predictions of design codes are made.
Date: January 30, 2006
Creator: Rosenzweig, J. B.; Cook, A. M.; Dunning, M. P.; Frigola, P.; Travish, G.; Sanelli, C. et al.
System: The UNT Digital Library