2005 Annual Health Physics Report for HEU Transparency Program (open access)

2005 Annual Health Physics Report for HEU Transparency Program

During the 2005 calendar year, LLNL provided health physics support for the Highly Enriched Uranium Transparency Program (HEU-TP) in external and internal radiation protection and technical expertise into matters related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2005, there were 161 person-trips that required dose monitoring of the U.S. monitors. Of the 161 person-trips, 149 person-trips were SMVs and 12 person-trips were Transparency Monitoring Office (TMO) trips. Additionally, there were 11 monitoring visits by TMO monitors to facilities other than UEIE and 3 to UEIE itself. There were two monitoring visits (source changes) that were back to back with 16 monitors. Each of these concurring visits were treated as single person-trips for dosimetry purposes. Counted individually, there were 191 individual person-visits in 2005. The LLNL Safety Laboratories Division provided the dosimetry services for the HEU-TP monitors.
Date: April 21, 2006
Creator: Radev, R
Object Type: Report
System: The UNT Digital Library
DSP-Based dual-polarity mass spectrum pattern recognition for bio-detection (open access)

DSP-Based dual-polarity mass spectrum pattern recognition for bio-detection

The Bio-Aerosol Mass Spectrometry (BAMS) instrument analyzes single aerosol particles using a dual-polarity time-of-flight mass spectrometer recording simultaneously spectra of thirty to a hundred thousand points on each polarity. We describe here a real-time pattern recognition algorithm developed at Lawrence Livermore National Laboratory that has been implemented on a nine Digital Signal Processor (DSP) system from Signatec Incorporated. The algorithm first preprocesses independently the raw time-of-flight data through an adaptive baseline removal routine. The next step consists of a polarity dependent calibration to a mass-to-charge representation, reducing the data to about five hundred to a thousand channels per polarity. The last step is the identification step using a pattern recognition algorithm based on a library of known particle signatures including threat agents and background particles. The identification step includes integrating the two polarities for a final identification determination using a score-based rule tree. This algorithm, operating on multiple channels per-polarity and multiple polarities, is well suited for parallel real-time processing. It has been implemented on the PMP8A from Signatec Incorporated, which is a computer based board that can interface directly to the two one-Giga-Sample digitizers (PDA1000 from Signatec Incorporated) used to record the two polarities of time-of-flight data. By using …
Date: April 21, 2006
Creator: Riot, V; Coffee, K; Gard, E; Fergenson, D; Ramani, S & Steele, P
Object Type: Article
System: The UNT Digital Library
Fluorine for Hydrogen Exchange in the Hydrofluorobenzene Derivatives C6HxF(6-x), where x = 2, 3, 4 and 5 by Monomeric [1,2,4-(Me3C)3C5H2]2CeH; The Solid State Isomerization of [1,2,4-(Me3C)3C5H2]2Ce(2,3,4,5-C6HF4) to [1,2,4-(Me3C)3C5H2]2Ce(2,3,4,6-C6HF4) (open access)

Fluorine for Hydrogen Exchange in the Hydrofluorobenzene Derivatives C6HxF(6-x), where x = 2, 3, 4 and 5 by Monomeric [1,2,4-(Me3C)3C5H2]2CeH; The Solid State Isomerization of [1,2,4-(Me3C)3C5H2]2Ce(2,3,4,5-C6HF4) to [1,2,4-(Me3C)3C5H2]2Ce(2,3,4,6-C6HF4)

The reaction between monomeric bis(1,2,4-tri-t-butylcyclopentadienyl)cerium hydride, Cp'2CeH, and several hydrofluorobenzene derivatives is described. The aryl derivatives that are the primary products, Cp'2Ce(C6H5-xFx) where x = 1,2,3,4, are thermally stable enough to be isolated in only two cases, since all of them decompose at different rates to Cp'2CeF and a fluorobenzyne; the latter is trapped by either solvent when C6D6 is used or by a Cp'H ring when C6D12 is the solvent. The trapped products are identified by GCMS analysis after hydrolysis. The aryl derivatives are generated cleanly by reaction of the metallacycle, Cp'((Me3C)2C5H2C(Me2)CH2)Ce, with a hydrofluorobenzene and the resulting arylcerium products, in each case, are identified by their 1H and 19F NMR spectra at 20oC. The stereochemical principle that evolves from these studies is that the thermodynamic isomer is the one in which the CeC bond is flanked by two ortho-CF bonds. This orientation is suggested to arise from the negative charge that is localized on the ipso-carbon atom due to Co(delta+)-Fo(delta-) polarization. The preferred regioisomer is determined by thermodynamic rather than kinetic effects; this is illustrated by the quantitative, irreversible solid-state conversion at 25oC over two months of Cp'2Ce(2,3,4,5-C6HF4) to Cp'2Ce(2,3,4,6-C6HF4), an isomerization that involves a CeC(ipso) for C(ortho)F …
Date: April 21, 2008
Creator: Andersen, Richard; Werkema, Evan L. & Andersen, Richard A.
Object Type: Article
System: The UNT Digital Library
Borehole Seismic Monitoring of Injected CO2 at the Frio Site (open access)

Borehole Seismic Monitoring of Injected CO2 at the Frio Site

As part of a small scale sequestration test (about 1500 tonsof CO2) in a saline aquifer, time-lapse borehole seismic surveys wereconducted to aid in characterization of subsurface CO2 distribution andmaterial property changes induced by the injected CO2. A VSP surveydemonstrated a large increase (about 75 percent) in seismic reflectivitydue to CO2 injection and allowed estimation of the spatial extent of CO2induced changes. A crosswell survey imaged a large seismic velocitydecrease (up to 500 m/s) within the injection interval and provided ahigh resolution image of this velocity change which maps the subsurfacedistribution of CO2 between two wells. Numerical modeling of the seismicresponse uses the crosswell measurements to show that this small CO2volume causes a large response in the seismic reflectivity. This resultdemonstrates that seismic detection of small CO2 volumes in salineaquifers is feasible and realistic.
Date: April 21, 2006
Creator: Daley, Thomas M.; Myer, Larry R.; Hoversten, G.M.; Peterson, JohnE. & Korneev, Valeri A.
Object Type: Article
System: The UNT Digital Library
A Beamline for High Pressure Studies at the Advanced Light Source With a Superconducting Bending Magnet as the Source (open access)

A Beamline for High Pressure Studies at the Advanced Light Source With a Superconducting Bending Magnet as the Source

A new facility for high-pressure diffraction and spectroscopy using diamond anvil high-pressure cells has been built at the Advanced Light Source on Beamline 12.2.2. This beamline benefits from the hard X-radiation generated by a 6 Tesla superconducting bending magnet (superbend). Useful x-ray flux is available between 5 keV and 35 keV. The radiation is transferred from the superbend to the experimental enclosure by the brightness preserving optics of the beamline. These optics are comprised of: a plane parabola collimating mirror (M1), followed by a Kohzu monochromator vessel with a Si(111) crystals (E/{Delta}E {approx} 7000) and a W/B{sub 4}C multilayer (E/{Delta}E {approx} 100), and then a toroidal focusing mirror (M2) with variable focusing distance. The experimental enclosure contains an automated beam positioning system, a set of slits, ion chambers, the sample positioning goniometry and area detectors (CCD or image-plate detector). Future developments aim at the installation of a second end station dedicated for in situ laser-heating on one hand and a dedicated high-pressure single-crystal station, applying both monochromatic as well as polychromatic techniques.
Date: April 21, 2005
Creator: Kunz, M.; MacDowell, A. A.; Caldwell, W. A.; Cambie, D.; Celestre, R. S.; Domning, E. E. et al.
Object Type: Article
System: The UNT Digital Library
Use of molecular modeling to determine the interaction and competition of gases within coal for carbon dioxide sequestration, Annual Technical Progress Report: 2005 (open access)

Use of molecular modeling to determine the interaction and competition of gases within coal for carbon dioxide sequestration, Annual Technical Progress Report: 2005

Molecular modeling was employed to both visualize and probe our understanding of carbon dioxide sequestration within a bituminous coal. A large-scale (>20,000 atoms) 3D molecular representation of Pocahontas No. 3 coal was generated. This model was constructed based on a the review data of Stock and Muntean, oxidation and decarboxylation data for aromatic clustersize frequency of Stock and Obeng, and the combination of Laser Desorption Mass Spectrometry data with HRTEM, enabled the inclusion of a molecular weight distribution. The model contains 21,931 atoms, with a molecular mass of 174,873 amu, and an average molecular weight of 714 amu, with 201 structural components. The structure was evaluated based on several characteristics to ensure a reasonable constitution (chemical and physical representation). The helium density of Pocahontas No. 3 coal is 1.34 g/cm{sup 3} (dmmf) and the model was 1.27 g/cm{sup 3}. The structure is microporous, with a pore volume comprising 34% of the volume as expected for a coal of this rank. The representation was used to visualize CO{sub 2}, and CH{sub 4} capacity, and the role of moisture in swelling and CO{sub 2}, and CH{sub 4} capacity reduction. Inclusion of 0.68% moisture by mass (ash-free) enabled the model to swell by …
Date: April 21, 2006
Creator: Evanseck, Jeffrey D.; Madura, Jeffry D. & Mathews, Jonathan P.
Object Type: Report
System: The UNT Digital Library
FLUOR HANFORD DECOMMISSIONING UPDATE (open access)

FLUOR HANFORD DECOMMISSIONING UPDATE

Fluor Hanford is completing D&D of the K East Basin at the U.S. Department of Energy's (DOE's) Hanford Site in southeastern Washington State this spring, with demolition expected to begin in June. Located about 400 yards from the Columbia River, the K East Basin is one of two indoor pools that formerly contained irradiated nuclear fuel, radioactive sludge and tons of contaminated debris. In unique and path-breaking work, workers finished removing the spent fuel from the K Basins in 2004. In May 2007, workers completed vacuuming the sludge into containers in the K East Basin, and transferring it into containers in the K West Basin. In December, they finished vacuuming the remainder of K West Basin sludge into these containers. The K East Basin was emptied of its radioactive inventory first because it was more contaminated than the K West Basin, and had leaked in the past. In October 2007, Fluor Hanford began physical D&D of the 8,400-square foot K East Basin by pouring approximately 14-inches of grout into the bottom of it. Grout is a type of special cement used for encasing waste. Two months later, Fluor Hanford workers completed sluicing contaminated sand from the large filter that had …
Date: April 21, 2008
Creator: MS, GERBER
Object Type: Article
System: The UNT Digital Library
Proceedings of RIKEN BNL Research Center Workshop entitled Hydrodynamics in Heavy Ion Collisions and QCD Equation of State (Volume 88) (open access)

Proceedings of RIKEN BNL Research Center Workshop entitled Hydrodynamics in Heavy Ion Collisions and QCD Equation of State (Volume 88)

The interpretation of relativistic heavy-ion collisions at RHIC energies with thermal concepts is largely based on the relative success of ideal (nondissipative) hydrodynamics. This approach can describe basic observables at RHIC, such as particle spectra and momentum anisotropies, fairly well. On the other hand, recent theoretical efforts indicate that dissipation can play a significant role. Ideally viscous hydrodynamic simulations would extract, if not only the equation of state, but also transport coefficients from RHIC data. There has been a lot of progress with solving relativistic viscous hydrodynamics. There are already large uncertainties in ideal hydrodynamics calculations, e.g., uncertainties associated with initial conditions, freezeout, and the simplified equations of state typically utilized. One of the most sensitive observables to the equation of state is the baryon momentum anisotropy, which is also affected by freezeout assumptions. Up-to-date results from lattice quantum chromodynamics on the transition temperature and equation of state with realistic quark masses are currently available. However, these have not yet been incorporated into the hydrodynamic calculations. Therefore, the RBRC workshop 'Hydrodynamics in Heavy Ion Collisions and QCD Equation of State' aimed at getting a better understanding of the theoretical frameworks for dissipation and near-equilibrium dynamics in heavy-ion collisions. The topics …
Date: April 21, 2008
Creator: Karsch, F.; Kharzeev, D.; Molnar, K.; Petreczky, P. & Teaney, D.
Object Type: Article
System: The UNT Digital Library
Security Proof for Password Authentication in TLS-Verifier-based Three-Party Group Diffie-Hellman (open access)

Security Proof for Password Authentication in TLS-Verifier-based Three-Party Group Diffie-Hellman

The internet has grown greatly in the past decade, by some numbers exceeding 47 million active web sites and a total aggregate exceeding100 million web sites. What is common practice today on the Internet is that servers have public keys, but clients are largely authenticated via short passwords. Protecting these passwords by not storing them in the clear on institutions's servers has become a priority. This paper develops password-based ciphersuites for the Transport Layer Security (TLS) protocol that are: (1) resistant to server compromise; (2) provably secure; (3) believed to be free from patent and licensing restrictions based on an analysis of relevant patents in the area.
Date: April 21, 2008
Creator: Chevassut, Olivier; Milner, Joseph & Pointcheval, David
Object Type: Report
System: The UNT Digital Library
Predicting dissolution patterns in variable aperture fractures: 1. Development and evaluation of an enhanced depth-averaged computational model (open access)

Predicting dissolution patterns in variable aperture fractures: 1. Development and evaluation of an enhanced depth-averaged computational model

Water-rock interactions within variable-aperture fractures can lead to dissolution of fracture surfaces and local alteration of fracture apertures, potentially transforming the transport properties of the fracture over time. Because fractures often provide dominant pathways for subsurface flow and transport, developing models that effectively quantify the role of dissolution on changing transport properties over a range of scales is critical to understanding potential impacts of natural and anthropogenic processes. Dissolution of fracture surfaces is controlled by surface-reaction kinetics and transport of reactants and products to and from the fracture surfaces. We present development and evaluation of a depth-averaged model of fracture flow and reactive transport that explicitly calculates local dissolution-induced alterations in fracture apertures. The model incorporates an effective mass transfer relationship that implicitly represents the transition from reaction-limited dissolution to transport-limited dissolution. We evaluate the model through direct comparison to previously reported physical experiments in transparent analog fractures fabricated by mating an inert, transparent rough surface with a smooth single crystal of potassium dihydrogen phosphate (KDP), which allowed direct measurement of fracture aperture during dissolution experiments using well-established light transmission techniques [Detwiler, et al., 2003]. Comparison of experiments and simulations at different flow rates demonstrate the relative impact of the …
Date: April 21, 2006
Creator: Detwiler, R L & Rajaram, H
Object Type: Article
System: The UNT Digital Library
PREPARATION AND CHARACTERIZATION OF POROUS WALLED HOLLOW GLASS MICROSPHERES (open access)

PREPARATION AND CHARACTERIZATION OF POROUS WALLED HOLLOW GLASS MICROSPHERES

Porous-walled hollow glass microspheres (PWHGMs) of a modified alkali borosilicate composition have been successfully fabricated by combining the technology of producing hollow glass microspheres (HGMs) with the knowledge associated with porous glasses. HGMs are first formed by a powder glass--flame process, which are then transformed to PWHGMs by heat treatment and subsequent treatment in acid. Pore diameter and pore volume are most influenced by heat treatment temperature. Pore diameter is increased by a factor of 10 when samples are heat treated prior to acid leaching; 100 {angstrom} in non-heat treated samples to 1000 {angstrom} in samples heat treated at 600 C for 8 hours. As heat treatment time is increased from 8 hours to 24 hours there is a slight shift increase in pore diameter and little or no change in pore volume.
Date: April 21, 2008
Creator: Raszewski, F; Erich Hansen, E; Ray Schumacher, R & David Peeler, D
Object Type: Article
System: The UNT Digital Library
Installation and Commissioning Automated Demand Response Systems (open access)

Installation and Commissioning Automated Demand Response Systems

Demand Response (DR) can be defined as actions taken to reduce electric loads when contingencies, such as emergencies and congestion, occur that threaten supply-demand balance, or market conditions raise supply costs. California utilities have offered price and reliability DR based programs to customers to help reduce electric peak demand. The lack of knowledge about the DR programs and how to develop and implement DR control strategies is a barrier to participation in DR programs, as is the lack of automation of DR systems. Most DR activities are manual and require people to first receive notifications, and then act on the information to execute DR strategies. Levels of automation in DR can be defined as follows. Manual Demand Response involves a labor-intensive approach such as manually turning off or changing comfort set points at each equipment switch or controller. Semi-Automated Demand Response involves a pre-programmed demand response strategy initiated by a person via centralized control system. Fully-Automated Demand Response does not involve human intervention, but is initiated at a home, building, or facility through receipt of an external communications signal. The receipt of the external signal initiates pre-programmed demand response strategies. We refer to this as Auto-DR (Piette et. al. 2005). …
Date: April 21, 2008
Creator: Partners, Global Energy; Company, Pacific Gas and Electric; Kiliccote, Sila; Kiliccote, Sila; Piette, Mary Ann; Wikler, Greg et al.
Object Type: Article
System: The UNT Digital Library
Laser System for Photoelectron and X-Ray Production in the PLEIADES Compton Light Source (open access)

Laser System for Photoelectron and X-Ray Production in the PLEIADES Compton Light Source

The PLEIADES (Picosecond Laser-Electron Interaction for the Dynamic Evaluation of Structures) facility provides tunable short x-ray pulses with energies of 30-140 keV and pulse durations of 0.3-5 ps by scattering an intense, ultrashort laser pulse off a 35-75 MeV electron beam. Synchronization of the laser and electron beam is obtained by using a photoinjector gun, and using the same laser system to generate the electrons and the scattering laser. The Ti Ti:Sapphire, chirped pulse amplification based 500 mJ, 50 fs, 810 nm scattering laser and the similar 300 {micro}J, 5 ps, 266 nm photoinjector laser systems are detailed. Additionally, an optical parametric chirped pulse amplification (OPCPA) system is studied as a replacement for part of the scattering laser front end. Such a change would significantly simplify the set-up the laser system by removing the need for active switching optics, as well as increase the pre-pulse contrast ratio which will be important when part of the scattering laser is used as a pump beam in pump-probe diffraction experiments using the ultrashort tunable x-rays generated as the probe.
Date: April 21, 2005
Creator: Gibson, D J; Barty, C J; Betts, S M; Crane, J K & Jovanovic, I
Object Type: Article
System: The UNT Digital Library
Precision Micron Hole Drilling using a Frequency Doubled, Diode Pumped Solid State Laser (open access)

Precision Micron Hole Drilling using a Frequency Doubled, Diode Pumped Solid State Laser

This work represents the second phase of a program to demonstrate precision laser drilling with minimal Heat Affected Zone. The technique uses a Diode Pumped Solid State Laser with two wavelengths and two modes of operation. The fundamental mode of the DPSSL at 1.06 microns is used to drill a hole with a diameter of a fraction of a millimeter diameter in a millimeter thick substrate quickly, but with low precision. This hole is then machined to precision dimensions using the second harmonic of the DPSSL Laser at 532 nm using a trepanning technique. Both lasers operate in the ablative mode with peak powers at or above a giga-watt per square centimeter and pulse durations in the 80 - 100 ns range. Under these conditions, the thermal diffusion distance is of the order of a micron or less and that fact coupled with the ablative nature of the process results in little or no HAZ (heat affected zone). With no HAZ, there isn't any change in the crystalline structure surrounding the hole and the strength of the substrate is maintained. Applications for these precision holes include cooling passages in turbine blades, ports for diesel injectors, suction holes for boundary layer …
Date: April 21, 2004
Creator: Friedman, H W & Pierce, E L
Object Type: Report
System: The UNT Digital Library
Estimation of (n,f) Cross-Sections by Measuring Reaction Probability Ratios (open access)

Estimation of (n,f) Cross-Sections by Measuring Reaction Probability Ratios

Neutron-induced reaction cross-sections on unstable nuclei are inherently difficult to measure due to target activity and the low intensity of neutron beams. In an alternative approach, named the 'surrogate' technique, one measures the decay probability of the same compound nucleus produced using a stable beam on a stable target to estimate the neutron-induced reaction cross-section. As an extension of the surrogate method, in this paper they introduce a new technique of measuring the fission probabilities of two different compound nuclei as a ratio, which has the advantage of removing most of the systematic uncertainties. This method was benchmarked in this report by measuring the probability of deuteron-induced fission events in coincidence with protons, and forming the ratio P({sup 236}U(d,pf))/P({sup 238}U(d,pf)), which serves as a surrogate for the known cross-section ratio of {sup 236}U(n,f)/{sup 238}U(n,f). IN addition, the P({sup 238}U(d,d{prime}f))/P({sup 236}U(d,d{prime}f)) ratio as a surrogate for the {sup 237}U(n,f)/{sup 235}U(n,f) cross-section ratio was measured for the first time in an unprecedented range of excitation energies.
Date: April 21, 2005
Creator: Plettner, C.; Ai, H.; Beausang, C. W.; Bernstein, L. A.; Ahle, L.; Amro, H. et al.
Object Type: Article
System: The UNT Digital Library
Environmental Management Waste Management Facility (EMWMF) Site-Specific Health and Safety Plan, Oak Ridge, Tennessee (open access)

Environmental Management Waste Management Facility (EMWMF) Site-Specific Health and Safety Plan, Oak Ridge, Tennessee

The Bechtel Jacobs Company LLC (BJC) policy is to provide a safe and healthy workplace for all employees and subcontractors. The implementation of this policy requires that operations of the Environmental Management Waste Management Facility (EMWMF), located one-half mile west of the U.S. Department of Energy (DOE) Y-12 National Security Complex, be guided by an overall plan and consistent proactive approach to environment, safety and health (ES&H) issues. The BJC governing document for worker safety and health, BJC/OR-1745, 'Worker Safety and Health Program', describes the key elements of the BJC Safety and Industrial Hygiene (IH) programs, which includes the requirement for development and implementation of a site-specific Health and Safety Plan (HASP) where required by regulation (refer also to BJC-EH-1012, 'Development and Approval of Safety and Health Plans'). BJC/OR-1745, 'Worker Safety and Health Program', implements the requirements for worker protection contained in Title 10 Code of Federal Regulations (CFR) Part 851. The EMWMF site-specific HASP requirements identifies safe operating procedures, work controls, personal protective equipment, roles and responsibilities, potential site hazards and control measures, site access requirements, frequency and types of monitoring, site work areas, decontamination procedures, and outlines emergency response actions. This HASP will be available on site for …
Date: April 21, 2008
Creator: Flynn, N.C. Bechtel Jacobs
Object Type: Report
System: The UNT Digital Library
Versatile P(acman) BAC Libraries for Transgenesis Studies in Drosophila melanogaster (open access)

Versatile P(acman) BAC Libraries for Transgenesis Studies in Drosophila melanogaster

We constructed Drosophila melanogaster BAC libraries with 21-kb and 83-kb inserts in the P(acman) system. Clones representing 12-fold coverage and encompassing more than 95percent of annotated genes were mapped onto the reference genome. These clones can be integrated into predetermined attP sites in the genome using Phi C31 integrase to rescue mutations. They can be modified through recombineering, for example to incorporate protein tags and assess expression patterns.
Date: April 21, 2009
Creator: Venken, Koen J.T.; Carlson, Joseph W.; Schulze, Karen L.; Pan, Hongling; He, Yuchun; Spokony, Rebecca et al.
Object Type: Article
System: The UNT Digital Library
New Accessory for Cleaning the Inside of the Machine Tool Cavity (open access)

New Accessory for Cleaning the Inside of the Machine Tool Cavity

The best way to extend the life of a metalworking fluid (MWF) is to make sure the machine tool and MWF delivery system are properly cleaned at least once per year. The dilemma the MWF manager is faced with is: How does one clean the machine tool and the MWF system on a large machine tool with an enclosure in a timely manner without impacting production schedules? Remember the walls and roof of the machine enclosure are coated with a film of dried contaminated MWF that must also be removed. If not removed, the deposits on these surfaces can recontaminate the fresh charge of MWF. I have found a product that with this revised procedure helps to shorten the machine tool down time involved with machine cleaning. (1) Discuss with your MWF supplier if they have a machine cleaning product that can be used with your current water based MWF during normal machining operations. Most MWF manufacturers have a machine cleaner that can be used at a lower concentration (1-2% vs. 5%) and can be used while still making production parts for a short period of time (usually 24-48 hours). (2) Make sure this machine cleaner is compatible with the …
Date: April 21, 2009
Creator: Lazarus, Lloyd
Object Type: Article
System: The UNT Digital Library
On Decays of B Mesons to a Strange Meson and an Eta or Eta' Meson at Babar (open access)

On Decays of B Mesons to a Strange Meson and an Eta or Eta' Meson at Babar

We describe studies of the decays of B mesons to final states {eta}K{sup *}(892), {eta}K{sup *}{sub 0}(S-wave), {eta}K{sup *}{sub 2}(1430), and {eta}'K based on data collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collier at the Stanford Linear Accelerator Center. We measure branching fractions and charge asymmetries for the decays B {yields} {eta}K{sup *}, where K{sup *} indicates a spin 0, 1, or 2 K{pi} system, making first observations of decays to final states {eta}K{sup *0}{sub 0}(S-wave), {eta}K{sup *+}{sub 0} (S-wave), and {eta}K{sup *0}{sub 2}(1430). We measure the time-dependent CP-violation parameters S and C for the decays B{sup 0} {yields} {eta}'K{sup 0}, observing CP violation in a charmless B decay with 5{sigma} significance considering both statistical and systematic uncertainties..
Date: April 21, 2009
Creator: Hirschauer, James Francis
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Development of Li+ alumino-silicate ion source (open access)

Development of Li+ alumino-silicate ion source

To uniformly heat targets to electron-volt temperatures for the study of warm dense matter, one strategy is to deposit most of the ion energy at the peak of energy loss (dE/dx) with a low (E< 5 MeV) kinetic energy beam and a thin target[1]. Lower mass ions have a peak dE/dx at a lower kinetic energy. To this end, a small lithium (Li+) alumino-silicate source has been fabricated, and its emission limit has been measured. These surface ionization sources are heated to 1000-1150 C where they preferentially emit singly ionized alkali ions. Alumino-silicates sources of K+ and Cs+ have been used extensively in beam experiments, but there are additional challenges for the preparation of high-quality Li+ sources: There are tighter tolerances in preparing and sintering the alumino-silicate to the substrate to produce an emitter that gives uniform ion emission, sufficient current density and low beam emittance. We report on recent measurements ofhigh ( up to 35 mA/cm2) current density from a Li+ source. Ion species identification of possible contaminants is being verified with a Wien (E x B) filter, and via time-of-flight.
Date: April 21, 2009
Creator: Roy, P.K.; Seidl, P.A.; Waldron, W.; Greenway, W.; Lidia, S.; Anders, A. et al.
Object Type: Article
System: The UNT Digital Library
Invariability of Central Metabolic Flux Distribution in Shewanella oneidensis MR-1 Under Environmental or Genetic Perturbations (open access)

Invariability of Central Metabolic Flux Distribution in Shewanella oneidensis MR-1 Under Environmental or Genetic Perturbations

An environmentally important bacterium with versatile respiration, Shewanella oneidensis MR-1, displayed significantly different growth rates under three culture conditions: minimal medium (doubling time {approx} 3 hrs), salt stressed minimal medium (doubling time {approx} 6 hrs), and minimal medium with amino acid supplementation (doubling time {approx}1.5 hrs). {sup 13}C-based metabolic flux analysis indicated that fluxes of central metabolic reactions remained relatively constant under the three growth conditions, which is in stark contrast to the reported significant changes in the transcript and metabolite profiles under various growth conditions. Furthermore, ten transposon mutants of S. oneidensis MR-1 were randomly chosen from a transposon library and their flux distributions through central metabolic pathways were revealed to be identical, even though such mutational processes altered the secondary metabolism, for example, glycine and C1 (5,10-Me-THF) metabolism.
Date: April 21, 2009
Creator: Tang, Yinjie; Martin, Hector Garcia; Deutschbauer, Adam; Feng, Xueyang; Huang, Rick; Llora, Xavier et al.
Object Type: Article
System: The UNT Digital Library
Final Technical Report (open access)

Final Technical Report

The purpose of this grant was to purchase equipment for biotechnology studies and courses at Saint Peter’s College (SPC). Equipment was used for courses such as Genetics and Biochemistry. The equipment helped SPC update its labs so as to create a better learning environment for our students.
Date: April 21, 2009
Creator: Petriello, Richard & Bonato, Frederick
Object Type: Report
System: The UNT Digital Library
EFFECTS OF GAMMA RADIATION ON ELECTROCHEMICAL PROPERTIES OF IONIC LIQUIDS (open access)

EFFECTS OF GAMMA RADIATION ON ELECTROCHEMICAL PROPERTIES OF IONIC LIQUIDS

The electrochemical properties of ionic liquids (ILs) make them attractive for possible replacement of inorganic salts in high temperature molten salt electrochemical processing of nuclear fuel. To be a feasible replacement solvent, ILs need to be stable in moderate and high doses of radiation without adverse chemical and physical effects. Here, we exposed seven different ILs to a 1.2 MGy dose of gamma radiation to investigate their physical and chemical properties as they related to radiological stability. The azolium-based ILs experienced the greatest change in appearance, but these ILs were chemically more stable to gamma radiation than some of the other classes of ILs tested, due to the presence of aromatic electrons in the azolium ring. All the ILs exhibited a decrease in their conductivity and electrochemical window (at least 1.1 V), both of which could affect the utility of ILs in electrochemical processing. The concentration of the irradiation decomposition products was less than 3 mole %, with no impurities detectable using NMR techniques.
Date: April 21, 2009
Creator: Visser, A; Nicholas Bridges, N; Thad Adams, T; John Mickalonis, J & Mark02 Williamson, M
Object Type: Article
System: The UNT Digital Library
Effect of Reducing Groundwater on the Retardation of Redox-Sensitive Radionuclides (open access)

Effect of Reducing Groundwater on the Retardation of Redox-Sensitive Radionuclides

Laboratory batch sorption experiments were used to investigate variations in the retardation behavior of redox-sensitive radionuclides. Water-rock compositions used during these experiments were designed to simulate subsurface conditions at the Nevada Test Site (NTS), where a suite of radionuclides were deposited as a result of underground nuclear testing. Experimental redox conditions were controlled by varying the oxygen content inside an enclosed glove box and by adding reductants into the testing solutions. Under atmospheric (oxidizing) conditions, the radionuclide distribution coefficients varied with the mineralogical composition of the sorbent and the water chemistry. Under reducing conditions, distribution coefficients showed marked increases for {sup 99}Tc and {sup 237}Np in devitrified tuff, but much smaller variations in alluvium, carbonate rock, and zeolitic tuff. This effect was particularly important for {sup 99}Tc, which tends to be mobile under oxidizing conditions. Unlike other redox-sensitive radionuclides, iodine sorption may decrease under reducing conditions when I{sup -} is the predominant species. Overall, sorption of U to alluvium, devitrified tuff, and zeolitic tuff under atmospheric conditions was less than in the glove-box tests. However, the mildly reducing conditions achieved here were not likely to result in substantial U(VI) reduction to U(IV). Sorption of Pu was not affected by the …
Date: April 21, 2008
Creator: Hu, Q; Zavarin, M & Rose, T P
Object Type: Article
System: The UNT Digital Library