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51st Annual Radiobioassay & Radiochemical Measurements Conference Proceedings (open access)

51st Annual Radiobioassay & Radiochemical Measurements Conference Proceedings

None
Date: October 10, 2005
Creator: Wong, C. & Lane, G.
System: The UNT Digital Library
Active Nuclear Material Detection and Imaging (open access)

Active Nuclear Material Detection and Imaging

An experimental evaluation has been conducted to assess the operational performance of a coded-aperture, thermal neutron imaging system and its detection and imaging capability for shielded nuclear material in pulsed photonuclear environments. This evaluation used an imaging system developed by Brookhaven National Laboratory. The active photonuclear environment was produced by an operationallyflexible, Idaho National Laboratory (INL) pulsed electron accelerator. The neutron environments were monitored using INL photonuclear neutron detectors. Results include experimental images, operational imaging system assessments and recommendations that would enhance nuclear material detection and imaging performance.
Date: October 1, 2005
Creator: Norman, Daren; Jones, James; KevinHaskell; Vanmier, Peter E. & Forman, Leon
System: The UNT Digital Library
Adaptive Perturbation Theory: Quantum Mechanics and Field Theory (open access)

Adaptive Perturbation Theory: Quantum Mechanics and Field Theory

Adaptive perturbation is a new method for perturbatively computing the eigenvalues and eigenstates of quantum mechanical Hamiltonians that are widely believed not to be solvable by such methods. The novel feature of adaptive perturbation theory is that it decomposes a given Hamiltonian, H, into an unperturbed part and a perturbation in a way which extracts the leading non-perturbative behavior of the problem exactly. In this talk I will introduce the method in the context of the pure anharmonic oscillator and then apply it to the case of tunneling between symmetric minima. After that, I will show how this method can be applied to field theory. In that discussion I will show how one can non-perturbatively extract the structure of mass, wavefunction and coupling constant renormalization.
Date: October 19, 2005
Creator: Weinstein, Marvin
System: The UNT Digital Library
Advances in Light-Front QCD and New Perspectives for QCD from AdS/CFT (open access)

Advances in Light-Front QCD and New Perspectives for QCD from AdS/CFT

The light-front quantization of gauge theories in light-cone gauge provides a frame-independent wavefunction representation of relativistic bound states, simple forms for current matrix elements, explicit unitarity, and a Fock space built on a trivial vacuum. The AdS/CFT correspondence has led to important insights into the properties of quantum chromodynamics even though QCD is a broken conformal theory. We have recently shown how a model based on a truncated AdS space can be used to obtain the hadronic spectrum of q{bar q}, qqq and gg bound states, as well as their respective light-front wavefunctions. Specific hadrons are identified by the correspondence of string modes with the dimension of the interpolating operator of the hadron's valence Fock state, including orbital angular momentum excitations. The predicted mass spectrum is linear M {proportional_to} L at high orbital angular momentum, in contrast to the quadratic dependence M{sup 2}/L found in the description of spinning strings. Since only one parameter, the QCD scale {Lambda}{sub QCD}, is introduced, the agreement with the pattern of physical states is remarkable. In particular, the ratio of {Delta} to nucleon trajectories is determined by the ratio of zeros of Bessel functions. As a specific application of QCD dynamics from AdS/CFT duality, …
Date: October 26, 2005
Creator: Brodsky, Stanley J. & de Teramond, Guy F.
System: The UNT Digital Library
After-hours Power Status of Office Equipment in the USA (open access)

After-hours Power Status of Office Equipment in the USA

Office equipment is expected to be the fastest-growingsegment of commercial energy use over the next 20 years, yet many aspectsof office equipment energy use are poorly understood. User behavior, suchas turning off devices at night or enabling power management, influencesenergy use to a great extent. The computing environment also plays a roleboth in influencing user behavior and in the success of power management.Information about turn-off rates and power management rates for officeequipment was collected through a series of after-hours audits incommercial buildings. Sixteen businesses were recruited, includingoffices (small, medium and large offices in a variety of industries),schools, and medical buildings in California, Georgia, and Pennsylvania.The types and power states of office equipment found in these buildingswere recorded and analyzed. This article presents these data forcomputers, monitors, printers, copiers, fax machines, scanners andmulti-function devices. These data can be used to improve estimates ofboth energy consumption for these devices and savings from energyconservation efforts.
Date: October 13, 2005
Creator: Webber, Carrie A.; Roberson, Judy A.; McWhinney, Marla C.; Brown,Richard E.; Pinckard, Margaret J. & Busch, John F.
System: The UNT Digital Library
Aggregated Transfer Factors For Small Mammals Collected From the Exposed Sediments Of A 137 Cs Contaminated Reservoir (open access)

Aggregated Transfer Factors For Small Mammals Collected From the Exposed Sediments Of A 137 Cs Contaminated Reservoir

{sup 137}Cs transfer factors were computed for small mammals collected from the dried sediment areas of a partially drained, contaminated reservoir. Soil {sup 137}Cs concentrations were heterogeneous on small and large spatial scales, with a geometric mean of 253.1 Bq/kg dry weight. About 50% of the variance in cotton rat Sigmodon hispidus tissue {sup 137}Cs levels was explained by variation in soil {sup 137}Cs levels. Soil to animal transfer factors (whole body dry weight) averaged 6.0 for cotton rats and 1.2 for cotton mice Peromyscus gossypinus. These values are similar to {sup 137}Cs transfer factors for herbivorous, homeothermic animals from other contaminated ecosystems. Site-specific transfer factors can significantly affect the estimation of dose. In the RESRAD-BIOTA dose model, the default transfer factor for {sup 137}Cs in terrestrial animals is 110 resulting in an estimate of radiation dose to terrestrial biota that is 16 times more than the dose calculated with the actual measured transfer factor.
Date: October 4, 2005
Creator: Paller, Michael H.; Jannika, G. Timothy & Wike, Lynn D
System: The UNT Digital Library
Aging Studies of Sr-doped LaCrO3/YSZ/Pt Cells for an Electrochemical NOx Sensor (open access)

Aging Studies of Sr-doped LaCrO3/YSZ/Pt Cells for an Electrochemical NOx Sensor

The stability and NO{sub x} sensing performance of electrochemical cells of the structure Sr-doped LaCrO{sub 3-{delta}} (LSC)/yttria-stabilized zirconia (YSZ)/Pt are being investigated for use in NO{sub x} aftertreatment systems in diesel vehicles. Among the requirements for NO{sub x} sensor materials in these systems are stability and long lifetime (up to ten years) in the exhaust environment. In this study, cell aging effects were explored following extended exposure to a test environment of 10% O{sub 2} at operating temperatures of 600-700 C. The data show that aging results in changes in particle morphology, chemical composition and interfacial structure, Impedance spectroscopy indicated an initial increase in the cell resistance during the early stages of aging, which is correlated to densification of the Pt electrode. Also, x-ray photoelectron spectroscopy indicated formation of SrZrO{sub 2} solid state reaction product in the LSC, a process which is of finite duration. Subsequently, the overall cell resistance decreases with aging time due, in part, to roughening of YSZ-LSC interface, which improves interface adherence and enhances charge transfer kinetics at the O{sub 2}/YSZ/LSC triple phase boundary. This study constitutes a first step in the development of a basic understanding of aging phenomena in solid state electrochemical systems with …
Date: October 5, 2005
Creator: Song, S.; Martin, L. P.; Glass, R. S.; Murray, E. P.; Visser, J. H.; Soltis, R. E. et al.
System: The UNT Digital Library
American Material Culture: Investigating a World War II Trash Dump (open access)

American Material Culture: Investigating a World War II Trash Dump

The Idaho National Laboratory: An Historical Trash Trove Historians and archaeologists love trash, the older the better. Sometimes these researchers find their passion in unexpected places. In this presentation, the treasures found in a large historic dump that lies relatively untouched in the middle of the Idaho National Laboratory (INL) will be described. The U.S. military used the central portion of the INL as one of only six naval proving grounds during World War II. They dumped trash in dry irrigation canals during and after their wartime activities and shortly before the federal government designated this arid and desolate place as the nation’s nuclear reactor testing station in 1949. When read critically and combined with memories and photographs, the 60-year old trash provides a glimpse into 1940s’ culture and the everyday lives of ordinary people who lived and worked during this time on Idaho’s desert. Thanks to priceless stories, hours of research, and the ability to read the language of historic artifacts, the dump was turned from just another trash heap into a treasure trove of 1940s memorabilia. Such studies of American material culture serve to fire our imaginations, enrich our understanding of past practices, and humanize history. Historical archaeology …
Date: October 1, 2005
Creator: Braun, Julie
System: The UNT Digital Library
American Material Culture: Investigating a World War II Trash Dump (open access)

American Material Culture: Investigating a World War II Trash Dump

The Idaho National Laboratory: An Historical Trash Trove Historians and archaeologists love trash, the older the better. Sometimes these researchers find their passion in unexpected places. In this presentation, the treasures found in a large historic dump that lies relatively untouched in the middle of the Idaho National Laboratory (INL) will be described. The U.S. military used the central portion of the INL as one of only six naval proving grounds during World War II. They dumped trash in dry irrigation canals during and after their wartime activities and shortly before the federal government designated this arid and desolate place as the nation’s nuclear reactor testing station in 1949. When read critically and combined with memories and photographs, the 60-year old trash provides a glimpse into 1940s’ culture and the everyday lives of ordinary people who lived and worked during this time on Idaho’s desert. Thanks to priceless stories, hours of research, and the ability to read the language of historic artifacts, the dump was turned from just another trash heap into a treasure trove of 1940s memorabilia. Such studies of American material culture serve to fire our imaginations, enrich our understanding of past practices, and humanize history. Historical archaeology …
Date: October 1, 2005
Creator: Braun, Julie
System: The UNT Digital Library
Anomaly-free sets of fermions (open access)

Anomaly-free sets of fermions

We present new techniques for finding anomaly-free sets of fermions. Although the anomaly cancellation conditions typically include cubic equations with integer variables that cannot be solved in general, we prove by construction that any chiral set of fermions can be embedded in a larger set of fermions which is chiral and anomaly-free. Applying these techniques to extensions of the Standard Model, we find anomaly-free models that have arbitrary quark and lepton charges under an additional U(1) gauge group.
Date: October 1, 2005
Creator: Batra, Puneet; Dobrescu, Bogdan A. & Spivak, David
System: The UNT Digital Library
An Approach Towards a Long-life, Microwave-assisted H- Ion Soucrefor Proton Drivers (open access)

An Approach Towards a Long-life, Microwave-assisted H- Ion Soucrefor Proton Drivers

This paper reports on experiments aimed at developing a new high-intensity H{sup -} ion source with long lifetime whose concept had recently been introduced. Starting from the motivation for this effort, several steps of the earlier development work are recapitulated, and the performance of the latest design variant is discussed in detail. The basic concept consists in coupling an ECR ion source to a standard SNS multi-cusp H{sup -} ion source that is driven by pulsed dc, rather than rf, power. As a key result, an electron beam of 1.5 A current has been extracted from the ECR discharge operating at 1.9 kW c. w. power, and a maximum discharge current of 17.5 A was achieved in the H{sup -} ion source. Production of H{sup -} ions, however could not yet been demonstrated in the one, preliminary, experiment conducted so far. The paper concludes by outlining further envisaged development steps for the plasma generator and an expansion towards a novel extraction system.
Date: October 26, 2005
Creator: Keller, R.; Regis, M.; Wallig, J.; Hahto, S.; Monroy, M.; Ratti, A. et al.
System: The UNT Digital Library
The ArcSDE GIS Dynamic Population Model Tool for Savannah River Site Emergency Response (open access)

The ArcSDE GIS Dynamic Population Model Tool for Savannah River Site Emergency Response

The Savannah River Site (SRS) is a 310-square-mile Department of Energy site located near Aiken, South Carolina. With a workforce of over 10,000 employees and subcontractors, SRS emergency personnel must be able to respond to an emergency event in a timely and effective manner, in order to ensure the safety and security of the Site. Geographic Information Systems (GIS) provides the technology needed to give managers and emergency personnel the information they need to make quick and effective decisions. In the event of a site evacuation, knowing the number of on-site personnel to evacuate from a given area is an essential piece of information for emergency staff. SRS has developed a GIS Dynamic Population Model Tool to quickly communicate real-time information that summarizes employee populations by facility area and building and then generates dynamic maps that illustrate output statistics.
Date: October 3, 2005
Creator: MCLANE, TRACY & JONES, DWIGHT
System: The UNT Digital Library
Are Quasar Jets Matter Or Poynting Flux Dominated? (open access)

Are Quasar Jets Matter Or Poynting Flux Dominated?

If quasar jets are accelerated by magnetic fields but terminate as matter dominated, where and how does the transition occur between the Poynting-dominated and matter-dominated regimes? To address this question, we study constraints which are imposed on the jet structure by observations at different spatial scales. We demonstrate that observational data are consistent with a scenario where the acceleration of a jet occurs within 10{sup 3-4}R{sub g}. In this picture, the non-thermal flares--important defining attributes of the blazar phenomenon--are produced by strong shocks formed in the region where the jet inertia becomes dominated by matter. Such shocks may be formed due to collisions between the portions of a jet accelerated to different velocities, and the acceleration differentiation is very likely to be related to global MHD instabilities.
Date: October 3, 2005
Creator: Sikora, Marek; /Warsaw, Copernicus Astron. Ctr.; Madejski, Greg M.; /SLAC /KIPAC, Menlo Park; Lasota, Jean-Pierre; /Paris, Inst. Astrophys. et al.
System: The UNT Digital Library
Assessment of a Single-Shot Pixelated Phase-Shifting Interferometer Utilizing a Liquid Crystal Spatial Light Modulator (open access)

Assessment of a Single-Shot Pixelated Phase-Shifting Interferometer Utilizing a Liquid Crystal Spatial Light Modulator

This article introduces a novel phase shifting pixelated interferometer based on a liquid crystal spatial light modulator and simulates the expected performance. The phase shifted frames are captured simultaneously which reduces the problems arising from vibrations and air turbulence. The liquid crystal spatial light modulator is very flexible and can be configured to provide a large number of phase shift levels and geometries to reduce the measurement error.
Date: October 1, 2005
Creator: Baker, K L & Stappaerts, E A
System: The UNT Digital Library
Assessment of RELAP5-3D for Analysis of Very High Temperature Gas-Cooled Reactors (open access)

Assessment of RELAP5-3D for Analysis of Very High Temperature Gas-Cooled Reactors

The RELAP5-3D© computer code is being improved for the analysis of very high temperature gas-cooled reactors. Diffusion and natural circulation can be important phenomena in gas-cooled reactors following a loss-of-coolant accident. Recent improvements to the code include the addition of models that simulate pressure loss across a pebble bed and molecular diffusion. These models were assessed using experimental data. The diffusion model was assessed using data from inverted U-tube experiments. The code’s capability to simulate natural circulation of air through a pebble bed was assessed using data from the NACOK facility. The calculated results were in reasonable agreement with the measured values.
Date: October 1, 2005
Creator: Oh, Chang; Siefken, Larry & Davis, Cliff
System: The UNT Digital Library
The "Athena Framework": Solving the World-wide Climate and Energy Problem (open access)

The "Athena Framework": Solving the World-wide Climate and Energy Problem

The energy systems we have enjoyed for the last 100 years has resulted in the advanced standard of living in the developed world and a major emerging problem with climate change. Now we face a simultaneous realization that our reliance on fossil fuels is a source of conflict and economic disruption as well as causing potentially catastrophic global climate change. It is time to give serious thought to how to collectively solve this problem. Collective action is critical since individual effort by one or only a few nations cannot adequately address the issue.
Date: October 10, 2005
Creator: Long, J S
System: The UNT Digital Library
Atomic-Nuclear Coupling Experiments (open access)

Atomic-Nuclear Coupling Experiments

Atomic-nuclear coupling experiments are described, with an emphasis on recent experiments aimed at demonstrating the NEET mechanism in atomic nuclei. Upper limits for x-ray induced decay of the Hf-178 31-y isomer reported by Ahmad and his colleagues are presented, and these upper limits are contrasted with the positive reports of Collins and coworkers.
Date: October 25, 2005
Creator: Becker, J. A.
System: The UNT Digital Library
Atomic Structure of Pyramidal Defects in GaN:Mg; Influence ofAnnealing (open access)

Atomic Structure of Pyramidal Defects in GaN:Mg; Influence ofAnnealing

The atomic structure of the characteristic defects (Mg-rich hexagonal pyramids) in p-doped bulk and MOCVD GaN:Mg thin films grown with Ga polarity was determined at atomic resolution by direct reconstruction of the scattered electron wave in a transmission electron microscope. Small cavities were present inside the defects, confirmed also with positron annihilation. The inside walls of the cavities were covered by GaN of reverse polarity compared to the matrix. Defects in bulk GaN:Mg were almost one order of magnitude larger than in thin films. An exchange of Ga and N sublattices within the defect compared to the matrix lead to a 0.6 {+-} 0.2 {angstrom} displacement between the Ga sublattices of these two areas. A [1100]/3 shift with change from AB stacking in the matrix to BC within the entire pyramid was observed. Annealing of the MOCVD layers lead to slight increase of the defect size and an increase of the photoluminescence intensity. Positron annihilation confirms presence of vacancies of different sizes triggered by the Mg doping in as-grown samples and decrease of their concentration upon annealing at 900 and 1000 C.
Date: October 3, 2005
Creator: Liliental-Weber, Z.; Tomaszewicz, T.; Zakharov, D.; O'Keefe, M.; Hautakangas, S.; Saarinen, K. et al.
System: The UNT Digital Library
B Decays to Open And Hidden Charm at BaBar (open access)

B Decays to Open And Hidden Charm at BaBar

A wealth of new measurements of hadronic B decays to open charm and charmonium have been performed on the data sample collected by the BaBar experiment at the PEP-II e{sup +}e{sup -} B-factory. We report the first measurement of the rates for inclusive charm production separately for charged and neutral B mesons. Combining measurements of the decay rate of B{sup 0} {yields} D*{sub s}{sup +}D*{sup -} obtained with a partial reconstruction technique and the complete reconstruction of B{sup 0} {yields} D*{sub s}{sup +}D*{sup -} with D{sub s}{sup +} {yields} {phi}{pi}{sup +}, we obtain the most precise measurement of {Beta}(D{sub s}{sup +} {yields} {phi}{pi}{sup +}). We present an update of the measurements of the branching fractions of exclusive B decays to J/{psi}, {psi}(2S), {chi}{sub c1}, {chi}{sub c2} and a kaon or a K*. In addition, we show preliminary results on exclusive decay rates to final states with baryons, or newly-discovered particles, such as D*{sub sJ}(2317), D{sub sJ}(2460){sup +}, and the X(3872).
Date: October 12, 2005
Creator: Ricciardi, S. & /Royal Holloway, U. of London
System: The UNT Digital Library
B meson mixing at CDF II (open access)

B meson mixing at CDF II

None
Date: October 1, 2005
Creator: Rescigno, Marco & /INFN, Rome
System: The UNT Digital Library
Baryon-strangeness correlations: a diagnostic of stronglyinteracting matter (open access)

Baryon-strangeness correlations: a diagnostic of stronglyinteracting matter

The correlation between baryon number and strangeness elucidates the nature of strongly interacting matter. This diagnostic can be extracted theoretically from lattice QCD calculations and experimentally from event-by-event fluctuations. The analysis of present lattice results above the critical temperature severely limits the presence of q{bar q} bound states, thus supporting a picture of independent (quasi)quarks. Details may be found in [1].
Date: October 7, 2005
Creator: Koch, Volker; Majumder, Abhijit & Randrup, Jorgen
System: The UNT Digital Library
Bent Marshak Waves (open access)

Bent Marshak Waves

Radiation driven heat waves (Marshak Waves) are ubiquitous in astrophysics and terrestrial laser driven high energy density plasma physics (HEDP) experiments. Generally, the equations describing Marshak waves are so nonlinear, that solutions involving more than one spatial dimension require simulation. However, in this paper we show how one may analytically solve the problem of the two-dimensional nonlinear evolution of a Marshak wave, bounded by lossy walls, using an asymptotic expansion in a parameter related to the wall albedo and a simplification of the heat front equation of motion. Three parameters determine the nonlinear evolution, a modified Markshak diffusion constant, a smallness parameter related to the wall albedo, and the spacing of the walls. The final nonlinear solution shows that the Marshak wave will be both slowed and bent by the non-ideal boundary. In the limit of a perfect boundary, the solution recovers the original diffusion-like solution of Marshak. The analytic solution will be compared to a limited set of simulation results and experimental data.
Date: October 11, 2005
Creator: Hurricane, O A & Hammer, J H
System: The UNT Digital Library
Bessel-Zernike Discrete Variable Representation Basis (open access)

Bessel-Zernike Discrete Variable Representation Basis

The connection between the Bessel discrete variable basis expansion and a specific form of an orthogonal set of Jacobi polynomials is demonstrated. These so-called Zernike polynomials provide alternative series expansions of suitable functions over the unit interval. Expressing a Bessel function in a Zernike expansion provides a straightforward method of generating series identities. Furthermore, the Zernike polynomials may also be used to efficiently evaluate the Hankel transform for rapidly decaying functions or functions with finite support.
Date: October 24, 2005
Creator: Cerjan, C J
System: The UNT Digital Library
Brilliant Bash (open access)

Brilliant Bash

Article about Alice Carrington Foulz's and Linda Pace's appearances in Brilliant Magazine and their Portrait Show to be held on November 3, 2005.
Date: October 23, 2005
Creator: Yerkes, Susan
System: The UNT Digital Library