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Use of DAC-Hours for Radiation Work Permit Suspension Guides and Validation of Respiratory Equipment Selection at the Savannah River Site (open access)

Use of DAC-Hours for Radiation Work Permit Suspension Guides and Validation of Respiratory Equipment Selection at the Savannah River Site

Historically, the Savannah River Site, like many Department of Energy sites, has used some multiple of the expected Derived Air Concentration (DAC) of a radionuclide as a suspension guide for Radiological Work Permits (RWP) or validation of selected respiratory protection equipment. The term DAC expresses the concentration of a radionuclide in air, typically in mCi/cc. Even though the term DAC is derived from an intake of radioactivity (Annual Limit on Intake) that would result in defined estimated dose to a worker, knowing only the DAC value does not allow a worker's potential dose to be determined. Recently, the Savannah Rive Site has converted to the use of DAC-hours for RWP suspension guides and respiratory equipment validation. The term DAC-hr takes into account not only the concentration of the radionuclide in air (DAC) but also the time the individual was exposed allowing an estimate of a worker's dose to be determined. The conversion to DAC-hrs resulted in four benefits to the radiation protection program without increasing the risk to workers; (1) consistency with the constant air monitor (CAM) alarm setpoint protocol; (2) consistency with Internal Dosimetry terminology; (3) an a priori determination of the potential risk to a worker; and (4) …
Date: October 30, 2003
Creator: Hadlock, D.J.
System: The UNT Digital Library
Preparations for EUV interferometry of the 0.3 NA MET optic (open access)

Preparations for EUV interferometry of the 0.3 NA MET optic

An at-wavelength interferometer is being created for the measurement and alignment of the 0.3 numerical aperture Micro Exposure Tool projection optic at EUV wavelengths. The prototype MET system promises to provide early learning from EUV lithographic imaging down to 20-nm feature size. The threefold increase to 0.3 NA in the image-side numerical aperture presents several challenges for the extension of ultra-high-accuracy interferometry, including pinhole fabrication and the calibration and removal of systematic error sources.
Date: October 30, 2003
Creator: Goldberg, Kenneth A.; Naulleau, Patrick P.; Denham, Paul E.; Rekawa, Senajith B.; Jackson, Keith H.; Liddle, J. Alexander et al.
System: The UNT Digital Library
Masses and branching fractions at CDF (open access)

Masses and branching fractions at CDF

The authors present a collection of new results on b-meson and {Lambda}{sub b} masses and branching fractions measured at CDF. They have improved the measurement of the {Lambda}{sub b} and B{sub s} mass and they have measured the branching fractions of B{sub s} {yields} D{sub s}{pi}, {Lambda}{sub b} {yields} {Lambda}{sub c}{pi} and B{sub u} {yields} {Phi}K{sup {+-}}.
Date: October 30, 2003
Creator: D'Auria, S.
System: The UNT Digital Library
Prospects for higgs search at D0 (open access)

Prospects for higgs search at D0

The D0 experiment is recording physics quality data. Both the detector and the accelerator performance are continually improving. We are studying issues such as the b{bar b} mass resolution, b-jet tagging efficiency, missing E{sub T} resolution, and backgrounds to Higgs processes. We look forward to seeing exciting results. The status of the Higgs search at the upgraded D0 detector is discussed.
Date: April 30, 2003
Creator: Snyder, Scott S.
System: The UNT Digital Library
Electrostatic interactions between peptides and the molecular chaperone DnaK (open access)

Electrostatic interactions between peptides and the molecular chaperone DnaK

None
Date: January 30, 2003
Creator: Liu, Wei; Bratko, Dusan; Prausnitz, J.M. & Blanch, H.W.
System: The UNT Digital Library
Overview of nuclear data (open access)

Overview of nuclear data

For many years, nuclear structure and decay data have been compiled and disseminated by an International Network of Nuclear Structure and Decay Data (NSDD) evaluators under the auspices of the International Nuclear Data Committee (INDC) of the International Atomic Energy Agency (IAEA). In this lecture I will discuss the kinds of data that are available and describe various ways to obtain this information. We will learn about some of the publications that are available and Internet sources of nuclear data. You will be introduced to Isotope Explorer software for retrieving and displaying nuclear structure and radioactive decay data. The on-line resources Table of Radioactive Isotopes, PGAA Database Viewer, Nuclear Science Reference Search, Table of Isotopes Educational Website, and other information sources will be discussed. Exercises will be provided to increase your ability to understand, access, and use nuclear data.
Date: June 30, 2003
Creator: Firestone, R.B.
System: The UNT Digital Library
The active fracture model: Its relation to fractal flow patterns and a further evaluation using field observations (open access)

The active fracture model: Its relation to fractal flow patterns and a further evaluation using field observations

None
Date: May 30, 2003
Creator: Liu, Hui-Hai; Zhang, Guoxiang & Bodvarsson, Gudmundur S.
System: The UNT Digital Library
Atmospheric Prognostic and Dispersion Model Design for use in the European Ensemble Modeling Exercises (open access)

Atmospheric Prognostic and Dispersion Model Design for use in the European Ensemble Modeling Exercises

The Savannah River Technology Center (SRTC) of the Department of Energy (DOE)Savannah River Site (SRS) has been involved with predicting the transport and dispersion of hazardous atmospheric releases for many years. The SRS utilizes an automated, real-time capability for consequence assessment during emergency response to local releases. The emphasis during these situations is to provide accurate guidance as quickly as possible. Consequently, atmospheric transport and dispersion models of a simple physical nature (such as Gaussian plume models) have typically been used in an effort to provide timely responses. However, use of one or two-dimensional (steady-state) winds are inadequate in conditions of high spatial and temporal variability (such as during frontal passage). Increased computing capabilities have led to the use of more sophisticated three dimensional prognostic models that may capture some of these higher resolution phenomena. In an ideal situation, the decision-maker would want to use the best model each time an accident occurred. Unfortunately, due to the nonunique nature of solutions to the nonlinear equations governing the atmosphere, model A may perform better than models B and C in one type of weather scenario, and worse during a different situation.Therefore, it is not always possible to distinguish which model is …
Date: October 30, 2003
Creator: Buckley, R. L.
System: The UNT Digital Library
BOA: Framework for automated builds (open access)

BOA: Framework for automated builds

Managing large-scale software products is a complex software engineering task. The automation of the software development, release and distribution process is most beneficial in the large collaborations, where the big number of developers, multiple platforms and distributed environment are typical factors. This paper describes Build and Output Analyzer framework and its components that have been developed in CMS to facilitate software maintenance and improve software quality. The system allows to generate, control and analyze various types of automated software builds and tests, such as regular rebuilds of the development code, software integration for releases and installation of the existing versions.
Date: September 30, 2003
Creator: al., N. Ratnikova et
System: The UNT Digital Library
Boron Addition to Model Austenitic Steels and void Nucleation (open access)

Boron Addition to Model Austenitic Steels and void Nucleation

Fe-15Cr-16Ni, -0.25Ti, -500appmB, and -0.25Ti-500appmB have been irradiated in FFTF/MOTA over a wide range of dose rate which covers more than two orders difference in magnitude, within the very limited temperature range of 387-444 C. The effects of dose rate and boron addition on swelling are examined. Lower dose rates increase the swelling by shortening the incubation dose for swelling. Addition of boron does not significantly change the swelling nor the dose rate dependence of swelling for both the ternary and Ti-modified alloy. The helium pressure of cavities is found to be much smaller than the surface tension at every irradiation condition including the lowest dose and dose rate, helium generated by boron transmutant does not play any role in cavity formation in this experiment. Cavities form without helium. The difference in cavity morphology by boron addition is most likely caused by formation of borides and by lithium.
Date: October 30, 2003
Creator: Okita, T; Wolfer, W G; Garner, F A & Sekimura, N
System: The UNT Digital Library
Studies of Electron Transport and Isochoric Heating and Their Applicability to Fast Ignition (open access)

Studies of Electron Transport and Isochoric Heating and Their Applicability to Fast Ignition

Experimental measurements of electron transport and isochoric heating in 100 J, 1 ps laser irradiation of solid A1 targets are presented. Modeling with a hybrid PIC code is compared with the data and good agreement is obtained using a heuristic model for the electron injection. The relevance for fast ignition is discussed.
Date: October 30, 2003
Creator: Key, M. H.; Amiranoff, F.; Andersen, C.; Batani, D.; Baton, S. D.; Cowan, T. et al.
System: The UNT Digital Library
Carcinogens formed when Meat is Cooked (open access)

Carcinogens formed when Meat is Cooked

Diet has been associated with varying cancer rates in human populations for many years, yet the causes of the observed variation in cancer patterns have not been adequately explained (Wynder et al. 1977). Along with the effect of diet on human cancer incidence is the strong evidence that mutations are the initiating events in the cancer process (Vogelstein et al. 1992). Foods, when heated, are a good source of genotoxic carcinogens that very likely are a cause for some of these events(Doll et al. 1981). These carcinogens fall into two chemical classes: heterocyclic aromatic amines (HAA) and polycyclic aromatic hydrocarbons (PAH). There is ample evidence that many of these compounds are complete carcinogens in rodents(El-Bayoumy et al. 1995; Ohgaki et al. 1991). Heterocyclic aromatic amines are among the most potent mutagenic substances ever tested in the Ames/Salmonella mutagenicity test (Wakabayashi et al. 1992). Both classes of carcinogen cause tumors in rodents at multiple sites, (El-Bayoumy et al. 1995; Ohgaki et al. 1991) many of which are common tumor sites in people on a Western diet. An HAA, PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine), and a PAH, B[a]P (benzo[a]pyrene), of comparable carcinogenic potency caused mammary gland tumors in a feeding study in female rats (El-Bayoumy …
Date: May 30, 2003
Creator: Felton, J S; Salmon, C P & Knize, M G
System: The UNT Digital Library
Incorporation of Chemical Reactions into Building-scale Flow (open access)

Incorporation of Chemical Reactions into Building-scale Flow

Many hazardous atmospheric releases involve chemical reactions that occur within a few kilometers of the source. Reactions with commonly occurring atmospheric compounds such as the OH radical, can transform and potentially neutralize original release compounds. Especially in these cases, accurately resolving flow around nearby structures and over surrounding topography can be critical to correctly predicting material dispersion, and thus, the extent of any hazard. Accurate prediction of material dispersion around complex geometries near the source of an atmospheric release requires high-resolution computation. Further complications arise if the compounds released undergo chemical reactions which could alter the extent of the main plume. The reaction products form dispersion patterns separate from, and often more complicated than, the original plume. Directions for future work include expanding the library of chemical reaction mechanisms, adding capabilities for aqueous and heterogeneous reactions, and integrating this model within larger-scale models. We plan that the larger-scale models will provide meteorological and chemical boundary conditions, and that this model could provide a source term in larger-scale models, both for momentum and for dispersed compounds.
Date: October 30, 2003
Creator: Humphreys, T D; Jayaweera, T M & Lee, R L
System: The UNT Digital Library
Current Drive and Pressure Profile Modifications with Electron Cyclotron Power in DIII-D Quiescent Double Barrier Experiments (open access)

Current Drive and Pressure Profile Modifications with Electron Cyclotron Power in DIII-D Quiescent Double Barrier Experiments

None
Date: June 30, 2003
Creator: Casper, T. A.; Burrell, K. H.; Doyle, E. J.; Gohil, P.; Greenfield, C. M.; Groebner, R. J. et al.
System: The UNT Digital Library
Scene-based Wave-front Sensing for Remote Imaging (open access)

Scene-based Wave-front Sensing for Remote Imaging

Scene-based wave-front sensing (SBWFS) is a technique that allows an arbitrary scene to be used for wave-front sensing with adaptive optics (AO) instead of the normal point source. This makes AO feasible in a wide range of interesting scenarios. This paper first presents the basic concepts and properties of SBWFS. Then it discusses that application of this technique with AO to remote imaging. For the specific case of correction of a lightweight optic. End-to-end simulation results establish that in this case, SBWFS can perform as well as point-source AO. Design considerations such as noise propagation, number of subapertures and tracking changing image content are analyzed.
Date: July 30, 2003
Creator: Poyneer, L A; LaFortune, K & Chan, C
System: The UNT Digital Library
Statistical Study of SCM Simulations Using Continuous Forcing Data Derived from NWP Products with the ARM Data Constraints (open access)

Statistical Study of SCM Simulations Using Continuous Forcing Data Derived from NWP Products with the ARM Data Constraints

Statistical study of Single Column Model (SCM) results has been recently advocated by the ARM cloud parameterization and modeling working group. This is partly due to the sensitivity nature of Single Column Models (SCMs) to uncertainties in the initial conditions and the specified large-scale forcing. In addition, given the limitation of SCM framework (e.g. the lack of effective internal feedback between the SCM and the specified forcing) and the inevitable error in the initial conditions and the large-scale forcing, it might not be realistic to expect that SCMs can correctly capture every individual synoptic event. Statistical studies can help smooth out those random errors related to uncertainties in the initial conditions and the specified large-scale forcing so that one can focus on those physically important systematic errors from SCM simulations. Noted that, for climate simulations, it is more important for a given physical parameterization to successfully simulate statistics right for the process that is being parameterized. This study conducts a statistical study of SCM simulations by using the ARM recently developed continuous forcing data for the year 2000. The NCAR CCM3 SCM is used in this study. The long-term continuous forcing data were developed from the NOAA mesoscale model RUC …
Date: June 30, 2003
Creator: Xie, S.; Cederwall, R.; Zhang, M. & Yio, J. J.
System: The UNT Digital Library
Measurement of the Branching Fraction for B- --->D0 K*- (open access)

Measurement of the Branching Fraction for B- --->D0 K*-

The authors present a measurement of the branching fraction for the decay B{sup -} {yields} D{sup 0} K{sup *-} using a sample of approximately 86 million B{bar B} pairs collected by the BABAR detector from e{sup +}e{sup -} collisions near the {Upsilon}(4S) resonance. The D{sup 0} is detected through its decays to K{sup -}{pi}{sup +}, K{sup -}{pi}{sup +}{pi}{sup 0} and K{sup -} {pi}{sup +}{pi}{sup -}{pi}{sup +}, and the K{sup *-} through its decay to K{sub S}{sup 0} {pi}{sup -}. They measure the branching fraction to be {Beta}(B{sup -} {yields} D{sup 0}K{sup *-}) = (6.3 {+-} 0.7(stat.){+-}0.5(syst.)) x 10{sup -4}.
Date: December 30, 2003
Creator: Lange, D J; Wright, D M; Simani, M C & Cheng, C H
System: The UNT Digital Library
A Multi-Resolution Data Structure for Two-Dimensional Morse Functions (open access)

A Multi-Resolution Data Structure for Two-Dimensional Morse Functions

The efficient construction of simplified models is a central problem in the field of visualization. We combine topological and geometric methods to construct a multi-resolution data structure for functions over two-dimensional domains. Starting with the Morse-Smale complex we build a hierarchy by progressively canceling critical points in pairs. The data structure supports mesh traversal operations similar to traditional multi-resolution representations.
Date: July 30, 2003
Creator: Bremer, P-T; Edelsbrunner, H; Hamann, B & Pascucci, V
System: The UNT Digital Library
Solubility in Binary Solvent Mixtures: Anthracene Dissolved in Alcohol + 2-Methyl-1-butanol Mixtures at 298.2 K (open access)

Solubility in Binary Solvent Mixtures: Anthracene Dissolved in Alcohol + 2-Methyl-1-butanol Mixtures at 298.2 K

Article on solubility in binary solvent mixtures and anthracene dissolved in alcohol + 2-methyl-1-butanol mixtures at 298.2 K.
Date: July 30, 2003
Creator: Monárrez, Cassandra I.; Taylor, Priscilla G.; Tran, Anh M. & Acree, William E. (William Eugene)
System: The UNT Digital Library
A new generation Nb3Sn wire, and the prospects for its use inparticle accelerators (open access)

A new generation Nb3Sn wire, and the prospects for its use inparticle accelerators

The US DOE has initiated a Conductor Development Program aimed at demonstrating a high current density, cost effective Nb3Sn conductor for use in accelerator magnets. The first goal, an increase in current density by 50%, has been achieved in a practical conductor. The program is focused at present on achieving the second goal of reduced losses. The different approaches for achieving these goals will be discussed, and the status will be presented. Magnet technology R&D has been proceeding in parallel with the conductor development efforts, and these two technologies are reaching the level required for the next step--introduction into operating accelerator magnets. An obvious point for introducing this technology is the LHC interaction region magnets, which require large apertures and high fields (or high field gradients). By upgrading the interaction region magnets, machine performance can be enhanced significantly without replacing the arc magnets, which represent most of the cost of an accelerator. Design requirements generated by recent studies and workshops will be reviewed, and a roadmap for the development of the next-generation interaction region magnets will be presented.
Date: September 30, 2003
Creator: Scanlan, R. M.; Dietderich, D. R. & Gourlay, S. A.
System: The UNT Digital Library
Specificity of anion-binding in the substrate-pocket ofbacteriorhodopsin (open access)

Specificity of anion-binding in the substrate-pocket ofbacteriorhodopsin

The structure of the D85S mutant of bacteriorhodopsin with a nitrate anion bound in the Schiff-base binding site, and the structure of the anion-free protein have been obtained in the same crystal form. Together with the previously solved structures of this anion pump, in both the anion-free state and bromide-bound state, these new structures provide insight into how this mutant of bacteriorhodopsin is able to bind a variety of different anions in the same binding pocket. The structural analysis reveals that the main structural change that accommodates different anions is the repositioning of the polar side-chain of S85. On the basis of these x-ray crystal structures, the prediction is then made that the D85S/D212N double mutant might bind similar anions and do so over a broader pH range than does the single mutant. Experimental comparison of the dissociation constants, K{sub d}, for a variety of anions confirms this prediction and demonstrates, in addition, that the binding affinity is dramatically improved by the D212N substitution.
Date: August 30, 2003
Creator: Facciotti, Marc T.; Cheung, Vincent S.; Lunde, Christopher S.; Rouhani, Shahab; Baliga, Nitin S. & Glaeser, Robert M.
System: The UNT Digital Library
Possible problems in ENDF/B-VI.r8 (open access)

Possible problems in ENDF/B-VI.r8

This document lists the problems that we encountered in processing ENDF/B-VI.r8 that we suspect are problems with ENDF/B-VI.r8 itself. It also contains a comparison of linear interpolation methods. Finally, this documents proposes an alternative to the current scheme of reporting problems to the ENDF community.
Date: October 30, 2003
Creator: Brown, David & Hedstrom, Gerry
System: The UNT Digital Library
Prospects for Investigating Unusual Nuclear Reaction Environments Using the National Ignition Facility (open access)

Prospects for Investigating Unusual Nuclear Reaction Environments Using the National Ignition Facility

The standard capsule design1 and other laser plasma targets at the National Ignition Facility offer the possibility of generating and studying thermal rates for significant astrophysical fusion reactions such as {sup 3}He({sup 3}He,2p){alpha}, {sup 7}Be(p,{gamma})B, and {sup 15}N(p,{alpha}){sup 12}C. At present the ''S'' factors for these reactions are determined either by extrapolation from higher energy scattering data or by underground laboratory, low event rate experiments such as at LUNA on un-ionized atoms with concomitantly large screening corrections. The ability to directly generate astrophysical fusion reactions in thermonuclear plasmas will be complemented by new, ab initio, ''no frozen core'' detailed shell model predictions for such light ion reactions. In addition, the expected fluence of neutrons from the main D + T {yields} {alpha} burn reaction, is high enough to drive 10-20% of seeded spectator nuclei into excited states via (n,n') reactions. Furthermore, the {approx}2% ''minority'' D + D {yields} {sup 3}He + n can drive reactions pertinent to the r, s, and p process nucleosynthesis of heavy elements, including branches that pass through excited states with t > 10 ps, that can be studied using particle spectroscopy and radiochemistry. Additionally, for the first time, it will be possible to measure the …
Date: September 30, 2003
Creator: Libby, S. B.; Tabak, M.; Hoffman, R. D.; Stoyer, M. A.; Haan, S. W.; Hatchett, S. P. et al.
System: The UNT Digital Library
Mullite/Mo interfaces formed by Intrusion bonding (open access)

Mullite/Mo interfaces formed by Intrusion bonding

The microstructure and strength of Mo/mullite interfaces formed by diffusion bonding at 1650 C has been analyzed. Interfacial metal-ceramic interlocking contributes to flexural strength of approx. 140 MPa as measured by 3 point bending. Saturation of mullite with MoO2 does not affect the interfacial strength.
Date: April 30, 2003
Creator: Bartolome, Jose F.; Diaz, Marcos; Moya, Jose S.; Saiz, Eduardo & Tomsia, Antoni P.
System: The UNT Digital Library