New Approaches for Collaborative Sharing of Chemical Model Data and Analysis Tools (open access)

New Approaches for Collaborative Sharing of Chemical Model Data and Analysis Tools

The urgent need for high-efficiency, low-emission energy utilization technologies for transportation, power generation, and manufacturing processes presents difficult challenges to the combustion research community. The required predictive understanding requires systematic knowledge across the full range of physical scales involved in combustion processes--from the properties and interactions of individual molecules to the dynamics and products of turbulent multi-phase reacting flows. Innovative experimental techniques and computational approaches are revolutionizing the rate at which chemical science research can produce the new information necessary to advance our combustion knowledge. But the increased volume and complexity of this information often makes it even more difficult to derive the systems-level knowledge we need. Combustion researchers have responded by forming interdisciplinary communities intent on sharing information and coordinating research priorities. Such efforts face many barriers, however, including lack of data accessibility and interoperability, missing metadata and pedigree information, efficient approaches for sharing data and analysis tools, and the challenges of working together across geography, disciplines, and a very diverse spectrum of applications and funding. This challenge is especially difficult for those developing, sharing and/or using detailed chemical models of combustion to treat the oxidation of practical fuels. This is a very complex problem, and the development of …
Date: January 19, 2005
Creator: Schuchardt, K; Oluwole, O; Pitz, W; Rahn, L A; Green, Jr., W H; Leahy, D et al.
Object Type: Article
System: The UNT Digital Library
Photocathodes for the Energy Recovery Linacs. (open access)

Photocathodes for the Energy Recovery Linacs.

This paper presents an overview of existing and emerging technologies on electron sources that can service various Energy Recovering Linacs under consideration. Photocathodes that can deliver average currents from 1 mA to 1 A, the pros and cons associated with these cathodes are addressed. Status of emerging technologies such as secondary emitters, cesiated dispenser cathodes, field and photon assisted field emitters and super lattice photocathodes are also reviewed.
Date: March 19, 2005
Creator: Rao, T.; Burrill, A.; Chang, X. Y.; Smedley, J. & Al., Et
Object Type: Article
System: The UNT Digital Library
PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 73, JET CORRELATIONS AT RHIC, MARCH 10-11, 2005. (open access)

PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 73, JET CORRELATIONS AT RHIC, MARCH 10-11, 2005.

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Date: April 19, 2005
Creator: GYULASSY, M.; TANNENBAUM, M. & WANG, F.
Object Type: Report
System: The UNT Digital Library
Differential Current Measurement in the Bnl Energy Recovery Linac Test Facility. (open access)

Differential Current Measurement in the Bnl Energy Recovery Linac Test Facility.

An Energy Recovery Linac (ERL) test facility is presently under construction at BNL [1,2]. The goal of this test facility is to demonstrate CW operation with an average beam current greater than 100mA, and with greater than 99.95% efficiency of current recovery. This facility will serve as a test bed for the novel high current CW photo-cathode [3,4], the superconducting RF cavity with HOM dampers [5,6], and the lattice [7,8] and feedback systems needed to insure the specified beam parameters. It is an important stepping stone for electron cooling in RHIC [9], and essential to meet the luminosity specifications of RHICII [10]. The expertise and experience gained in this effort might also extend forward into a 10-20GeV ERL for the electron-ion collider eRHIC [11]. We report here on the use of a technique of differential current measurement to monitor the efficiency of current recovery in the test facility, and investigate the possibility of using such a monitor in the machine protection system.
Date: March 19, 2005
Creator: Cameron, P.
Object Type: Article
System: The UNT Digital Library
The Second Phase of the Atmospheric Model Intercomparison Project (AMIP2) (open access)

The Second Phase of the Atmospheric Model Intercomparison Project (AMIP2)

None
Date: January 19, 2005
Creator: Gleckler, P
Object Type: Article
System: The UNT Digital Library
Chemical Conversion of Energetic Materials to Higher Value Products (open access)

Chemical Conversion of Energetic Materials to Higher Value Products

The objective of this program is to develop new processes for the disposal of surplus energetic materials. Disposal through open burning/open detonation (OB/OD) is considered less attractive today due to environmental, cost and safety concerns. The use of energetic materials as chemical feedstocks for higher value products can provide environmentally sound and cost-effective alternatives to OB/OD. Our recent studies on the conversion of surplus energetic materials (Explosive D, TNT) to higher value products will be described.
Date: April 19, 2005
Creator: Mitchell, A. R.; Hsu, P. C.; Coburn, M. D.; Schmidt, R. D.; Pagoria, P. F. & Lee, G. S.
Object Type: Article
System: The UNT Digital Library
HIGH ENERGY, HIGH BRIGHTNESS X-RAYS PRODUCED BY COMPTON BACKSCATTERING AT THE LIVERMORE PLEIADES FACILITY (open access)

HIGH ENERGY, HIGH BRIGHTNESS X-RAYS PRODUCED BY COMPTON BACKSCATTERING AT THE LIVERMORE PLEIADES FACILITY

PLEIADES (Picosecond Laser Electron Interaction for the Dynamic Evaluation of Structures) produces tunable 30-140 keV x-rays with 0.3-5 ps pulse lengths and up to 10{sup 7} photons/pulse by colliding a high brightness electron beam with a high power laser. The electron beam is created by an rf photo-injector system, accelerated by a 120 MeV linac, and focused to 20 {micro}m with novel permanent magnet quadrupoles. To produce Compton back scattered x-rays, the electron bunch is overlapped with a Ti:Sapphire laser that delivers 500 mJ, 100 fs, pulses to the interaction point. K-edge radiography at 115 keV on Uranium has verified the angle correlated energy spectrum inherent in Compton scattering and high-energy tunability of the Livermore source. Current upgrades to the facility will allow laser pumping of targets synchronized to the x-ray source enabling dynamic diffraction and time-resolved studies of high Z materials. Near future plans include extending the radiation energies to >400 keV, allowing for nuclear fluorescence studies of materials.
Date: May 19, 2005
Creator: Tremaine, A. M.; Anderson, S. G.; Betts, S.; Crane, J.; Gibson, D. J.; Hartemann, F. V. et al.
Object Type: Article
System: The UNT Digital Library
Hanford Site Environmental Surveillance Master Sampling Schedule for Calendar Year 2005 (open access)

Hanford Site Environmental Surveillance Master Sampling Schedule for Calendar Year 2005

Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE). Sampling is conducted to evaluate levels of radioactive and nonradioactive pollutants in the Hanford environs. This document contains the calendar year 2005 schedules for the routine and non-routine collection of samples for the Surface Environmental Surveillance Project (SESP) and Drinking Water Monitoring Project.
Date: January 19, 2005
Creator: Bisping, Lynn E.
Object Type: Report
System: The UNT Digital Library
Radiological Instrumentation Assessment for King County Wastewater Treatment Division (open access)

Radiological Instrumentation Assessment for King County Wastewater Treatment Division

The King County Wastewater Treatment Division (WTD) have concern about the aftermath of a radiological dispersion event (RDE) leading to the introduction of significant quantities of radioactive material into its combined sanitary and storm sewer system. Radioactive material could come from the use of a radiological dispersion device (RDD). RDDs include "dirty bombs" that are not nuclear detonations but are explosives designed to spread radioactive material. Radioactive material also could come from deliberate introduction or dispersion of radioactive material into the environment, including waterways and water supply systems. Volume 2 of PNNL-15163 assesses the radiological instrumentation needs for detection of radiological or nuclear terrorism, in support of decisions to treat contaminated wastewater or to bypass the West Point Treatment Plant (WPTP), and in support of radiation protection of the workforce, the public, and the infrastructure of the WPTP. Fixed radiation detection instrumentation should be deployed in a defense-in-depth system that provides 1) early warning of significant radioactive material on the way to the WPTP, including identification of the radionuclide(s) and estimates of the soluble concentrations, with a floating detector located in the wet well at the Interbay Pump Station and telemetered via the internet to all authorized locations; 2) monitoring …
Date: May 19, 2005
Creator: Strom, Daniel J.; McConn, Ronald J. & Brodzinski, Ronald L.
Object Type: Report
System: The UNT Digital Library
New cubic phase of lithium nitride to 200 GPa (open access)

New cubic phase of lithium nitride to 200 GPa

We present a new cubic ({gamma}) Li{sub 3}N phase discovered above 40({+-}5) GPa. Structure and electronic bands are examined at high pressure with synchrotron x-ray diffraction and inelastic x-ray scattering in a diamond anvil cell, and also with first-principles calculations. We observe a dramatic band-gap widening and volume collapse at the phase transition. {gamma}-Li{sub 3}N remains extremely stable and ionic to 200 GPa, with predicted metallization near 8 TPa. The high structural stability, wide band-gap and simple electronic structure of {gamma}-Li{sub 3}N are analogous to that of such lower valence closed-shell solids as NaCl, MgO and Ne, meriting its use as a low-Z internal pressure standard.
Date: July 19, 2005
Creator: Lazicki, A.; Maddox, B.; Evans, W.; Yoo, C. S.; McMahan, A. K.; Pickett, W. E. et al.
Object Type: Article
System: The UNT Digital Library
General Corrosion and Passive Film Stability (open access)

General Corrosion and Passive Film Stability

This report summarizes both general corrosion of Alloy 22 from 60 to 220 C and the stability of the passive (oxide) film from 60 to 90 C over a range of solution compositions that are relevant to the in-drift chemical environment at the waste package surface. The general corrosion rates were determined by weight-loss measurements in a range of complex solution compositions representing the products of both the evaporation of seepage water and also the deliquescence of dust previously deposited on the waste canisters. These data represent the first weight-loss measurements performed by the program at temperatures above 90 C. The low corrosion rates of Alloy 22 are attributed to the protective oxide film that forms at the metal surface. In this report, changes in the oxide film composition are correlated with weight loss at the higher temperatures (140-220 C) where film characterization had not been previously performed. The stability of the oxide film was further analyzed by conducting a series of electrochemical tests in progressively more acidic solutions to measure the general corrosion rates in solutions that mimic crevice or pit environments.
Date: July 19, 2005
Creator: Orme, C; Gray, J; Hayes, J; Wong, L; Rebak, R; Carroll, S et al.
Object Type: Report
System: The UNT Digital Library
Infrared Lorentz Violation and Slowly InstantaneousElectricity (open access)

Infrared Lorentz Violation and Slowly InstantaneousElectricity

None
Date: January 19, 2005
Creator: Dvali, Gia; Papucci, Michele & Schwartz, Matthew D.
Object Type: Article
System: The UNT Digital Library
Calibration of Small Plastic Scintillators for Imaging Applications (open access)

Calibration of Small Plastic Scintillators for Imaging Applications

This report presents the results of measurements and simulations performed with 12 small plastic scintillation detectors manufactured by Scionix for imaging applications. The scintillator is equivalent to a Bicron BC-420 plastic scintillator. A gamma calibration is presented to determine the voltage to be applied on each detector to ensure uniform detector operation. Time of flight measurements performed with a Cf-252 source are also presented. Comparisons between experimental data and data from the Monte Carlo simulations show good agreement for time lags of 0 to 70 ns.
Date: January 19, 2005
Creator: Pozzi, S.
Object Type: Report
System: The UNT Digital Library
TRANSPARENCY: Tracking Uranium under the U.S. / Russian HEU Purchase Agreement (open access)

TRANSPARENCY: Tracking Uranium under the U.S. / Russian HEU Purchase Agreement

By the end of August, 2005, the Russia Federation delivered to the United States (U.S.) more than 7,000 metric tons (MT) of low enriched uranium (LEU) containing approximately 46 million SWU and 75,000 MT of natural uranium. This uranium was blended down from weapons-grade (nominally enriched to 90% {sup 235}U) highly enriched uranium (HEU) under the 1993 HEU Purchase Agreement that provides for the blend down of 500 MT HEU into LEU for use as fuel in commercial nuclear reactors. The HEU Transparency Program, under the National Nuclear Security Administration (NNSA), monitored the conversion and blending of the more than 250 MT HEU used to produce this LEU. The HEU represents more than half of the 500 MT HEU scheduled to be blended down through the year 2013 and is equivalent to the elimination of more than 10,000 nuclear devices. The HEU Transparency Program has made considerable progress in its mission to develop and implement transparency measures necessary to assure that Russian HEU extracted from dismantled Russian nuclear weapons is blended down into LEU for delivery to the United States. U.S. monitor observations include the inventory of in process containers, observation of plant operations, nondestructive assay measurements to determine {sup …
Date: October 19, 2005
Creator: Benton, J B; Decman, D J & Leich, D A
Object Type: Article
System: The UNT Digital Library
Predictive Assay For Cancer Targets (open access)

Predictive Assay For Cancer Targets

Early detection of cancer is a key element in successful treatment of the disease. Understanding the particular type of cancer involved, its origins and probable course, is also important. PhIP (2-amino-1-methyl-6 phenylimidazo [4,5-b]pyridine), a heterocyclic amine produced during the cooking of meat at elevated temperatures, has been shown to induce mammary cancer in female, Sprague-Dawley rats. Tumors induced by PhIP have been shown to contain discreet cytogenetic signature patterns of gains and losses using comparative genomic hybridization (CGH). To determine if a protein signature exists for these tumors, we are analyzing expression levels of the protein products of the above-mentioned tumors in combination with a new bulk protein subtractive assay. This assay produces a panel of antibodies against proteins that are either on or off in the tumor. Hybridization of the antibody panel onto a 2-D gel of tumor or control protein will allow for identification of a distinct protein signature in the tumor. Analysis of several gene databases has identified a number of rat homologs of human cancer genes located in these regions of gain and loss. These genes include the oncogenes c-MYK, ERBB2/NEU, THRA and tumor suppressor genes EGR1 and HDAC3. The listed genes have been shown to …
Date: September 19, 2005
Creator: Suess, A.; Nguyen, C.; Sorensen, K.; Montgomery, J.; Souza, B.; Kulp, K. et al.
Object Type: Article
System: The UNT Digital Library
Sphere-Pac Evaluation for Transmutation (open access)

Sphere-Pac Evaluation for Transmutation

The U.S. Department of Energy Advanced Fuel Cycle Initiative (AFCI) is sponsoring a project at Oak Ridge National Laboratory with the objective of conducting the research and development necessary to evaluate the use of sphere-pac transmutation fuel. Sphere-pac fuels were studied extensively in the 1960s and 1970s. More recently, this fuel form is being studied internationally as a potential plutonium-burning fuel. For transmutation fuel, sphere-pac fuels have potential advantages over traditional pellet-type fuels. This report provides a review of development efforts related to the preparation of sphere-pac fuels and their irradiation tests. Based on the results of these tests, comparisons with pellet-type fuels are summarized, the advantages and disadvantages of using sphere-pac fuels are highlighted, and sphere-pac options for the AFCI are recommended. The Oak Ridge National Laboratory development activities are also outlined.
Date: May 19, 2005
Creator: Icenhour, A.S.
Object Type: Report
System: The UNT Digital Library
Transport of Radioactive Material by Alpha Recoil (open access)

Transport of Radioactive Material by Alpha Recoil

The movement of high-specific-activity radioactive particles (i.e., alpha recoil) has been observed and studied since the early 1900s. These studies have been motivated by concerns about containment of radioactivity and the protection of human health. Additionally, studies have investigated the potential advantage of alpha recoil to effect separations of various isotopes. This report provides a review of the observations and results of a number of the studies.
Date: May 19, 2005
Creator: Icenhour, A.S.
Object Type: Report
System: The UNT Digital Library
RADIONUCLIDE TRANSPORT IN FRACTURED TUFF UNDER EPISODIC FLOW CONDITIONS (open access)

RADIONUCLIDE TRANSPORT IN FRACTURED TUFF UNDER EPISODIC FLOW CONDITIONS

The current conceptual model of radionuclide transport in unsaturated fractured rock includes water movement in fractures, with migration of the entrained radionuclides being retarded by diffusion into and sorption within the rock matrix. Water infiltration and radionuclide transport through low-permeability unsaturated fractured rock are episodic and intermittent in nature, at least at local scales. Under episodic flow conditions, the matrix is constantly imbibing or draining, and this fluctuating wetness both drives two-way advective movement of radionuclides, and forces changes in the matrix diffusivity. This work is intended to examine, both experimentally and numerically, how radionuclide transport under episodic flow conditions is affected by the interacting processes of imbibition and drainage, diffusion, and matrix sorption. Using Topopah Spring welded volcanic tuff, collected from the potential repository geologic unit at Yucca Mountain for storing high-level nuclear waste, we prepared a saw-cut fracture core (length 10.2 cm, diameter 4.4 cm, and fracture aperture 100 {micro}m). The dry core was packed into a flow reactor, flushed with CO{sub 2}, then saturated via slow pumping (0.01 mL/min) of synthetic groundwater. The fractured core was then flushed with air at >97% relative humidity (to simulate in situ unsaturated fractured rock conditions at Yucca Mountain), then the …
Date: September 19, 2005
Creator: Hu, O.; Sun, Y. & Ewing, R.P.
Object Type: Report
System: The UNT Digital Library
Accelerator mass spectrometry for quantitative in vivo tracing (open access)

Accelerator mass spectrometry for quantitative in vivo tracing

Accelerator mass spectrometry (AMS) counts individual rare, usually radio-, isotopes such as radiocarbon at high efficiency and specificity in milligram-sized samples. AMS traces very low chemical doses ({micro}g) and radiative doses (100 Bq) of isotope labeled compounds in animal models and directly in humans for pharmaceutical, nutritional, or toxicological research. Absorption, metabolism, distribution, binding, and elimination are all quantifiable with high precision after appropriate sample definition.
Date: April 19, 2005
Creator: Vogel, J S
Object Type: Article
System: The UNT Digital Library
CONSIDERATIONS OF THE ROLE OF THE CATHODIC REGION IN LOCALIZED CORROSION (open access)

CONSIDERATIONS OF THE ROLE OF THE CATHODIC REGION IN LOCALIZED CORROSION

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Date: December 19, 2005
Creator: KELLY, R.G., LANDAU, U., PAYER, J.H.
Object Type: Article
System: The UNT Digital Library
Waste Package Corrosion Studies Using Small Mockup Experiments (open access)

Waste Package Corrosion Studies Using Small Mockup Experiments

The corrosion of spent nuclear fuel and subsequent mobilization of radionuclides is of great concern in a geologic repository, particularly if conditions are oxidizing. Corroding A516 steel may offset these transport processes within the proposed waste packages at the Yucca Mountain Repository (YMR) by retaining radionuclides, creating locally reducing conditions, and reducing porosity. Ferrous iron, Fe{sup 2+}, has been shown to reduce UO{sub 2}{sup 2+} to UO{sub 2(s)} [1], and some ferrous iron-bearing ion-exchange materials adsorb radionuclides and heavy metals [2]. Of particular interest is magnetite, a potential corrosion product that has been shown to remove TcO{sub 4}{sup -} from solution [3]. Furthermore, if Fe{sup 2+} minerals, rather than fully oxidized minerals such as goethite, are produced during corrosion, then locally reducing conditions may be present. High electron availability leads to the reduction and subsequent immobilization of problematic dissolved species such as TcO{sub 4}{sup -}, NpO{sub 2}{sup +}, and UO{sub 2}{sup 2+} and can also inhibit corrosion of spent nuclear fuel. Finally, because the molar volume of iron material increases during corrosion due to oxygen and water incorporation, pore space may be significantly reduced over long time periods. The more water is occluded, the bulkier the corrosion products, and the …
Date: October 19, 2005
Creator: Anderson, B. E.; Helean, K. B.; Bryan, C. R.; Brady, P. V. & Ewing, R. C.
Object Type: Report
System: The UNT Digital Library
Transition to a Virtually Incompressible Oxide Phase at a Shock Pressure of 120 GPa (1.2 Mbar): Gd3Ga5O12 (open access)

Transition to a Virtually Incompressible Oxide Phase at a Shock Pressure of 120 GPa (1.2 Mbar): Gd3Ga5O12

Cubic, single-crystal, transparent Gd{sub 3}Ga{sub 5}O{sub 12} has a density of 7.10 g/cm{sup 3}, a Hugoniot elastic limit (HEL) of 30 GPa, and undergoes a continuous phase transition from 65 GPa to a quasi-incompressible (QI) phase at 120 GPa. Only diamond has a larger HEL. The QI phase of Gd{sub 3}Ga{sub 5}O{sub 12} is more incompressible than diamond from 170 to 260 GPa. Electrical conductivity measurements indicate the QI phase has a bandgap of 3.1 eV. Gd{sub 3}Ga{sub 5}O{sub 12} can be used to obtain substantially higher pressures and lower temperatures in metallic fluid hydrogen than was achieved previously by shock reverberation between Al{sub 2}O{sub 3} disks. Dynamic compression achieves pressures, densities, and temperatures that enable investigation of ultracondensed matter at conditions yet to be achieved by any other technique. The prototypical example is observation of minimum metallic conductivity (MMC) of dense fluid hydrogen at 140 GPa, nine-fold compression of liquid density, and {approx}3000 K [1-3]. The high pressure and density and relatively low temperature are achieved by multiple-shock compression [2]. Temperature T is relatively low in the sense that T/TP{sub F} {approx} 0.01, where T{sub F} is the Fermi temperature. The time scale of compression is sufficiently long to …
Date: September 19, 2005
Creator: Mashimo, T; Chau, R; Zhang, Y; Kobayoshi, T; Sekine, T; Fukuoka, K et al.
Object Type: Article
System: The UNT Digital Library
Atmospheric Dispersion Capability for T2VOC (open access)

Atmospheric Dispersion Capability for T2VOC

Atmospheric transport by variable-K theory dispersion has been added to T2VOC. The new code, T2VOCA, models flow and transport in the subsurface identically to T2VOC, but includes also the capability for modeling passive multicomponent variable-K theory dispersion in an atmospheric region assumed to be flat, horizontal, and with a logarithmic wind profile. The specification of the logarithmic wind profile in the T2VOC input file is automated through the use of a build code called ATMDISPV. The new capability is demonstrated on 2-D and 3-D example problems described in this report.
Date: September 19, 2005
Creator: Oldenburg, Curtis M.
Object Type: Report
System: The UNT Digital Library
Securing Resources in Collaborative Environments: A Peer-to-peerApproach (open access)

Securing Resources in Collaborative Environments: A Peer-to-peerApproach

We have developed a security model that facilitates control of resources by autonomous peers who act on behalf of collaborating users. This model allows a gradual build-up of trust. It enables secure interactions among users that do not necessarily know each other and allows them to build trust over the course of their collaboration. This paper describes various aspects of our security model and describes an architecture that implements this model to provide security in pure peer-to-peer environments.
Date: September 19, 2005
Creator: Berket, Karlo; Essiari, Abdelilah & Thompson, Mary R.
Object Type: Article
System: The UNT Digital Library