States

Evaluation of High Dynamic Range Photography as a Luminance Mapping Technique (open access)

Evaluation of High Dynamic Range Photography as a Luminance Mapping Technique

The potential, limitations, and applicability of the High Dynamic Range (HDR) photography technique is evaluated as a luminance mapping tool. Multiple exposure photographs of static scenes are taken with a Nikon 5400 digital camera to capture the wide luminance variation within the scenes. The camera response function is computationally derived using the Photosphere software, and is used to fuse the multiple photographs into HDR images. The vignetting effect and point spread function of the camera and lens system is determined. Laboratory and field studies have shown that the pixel values in the HDR photographs can correspond to the physical quantity of luminance with reasonable precision and repeatability.
Date: December 30, 2004
Creator: Inanici, Mehlika & Galvin, Jim
Object Type: Report
System: The UNT Digital Library
Modeling Power Systems as Complex Adaptive Systems (open access)

Modeling Power Systems as Complex Adaptive Systems

Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.
Date: December 30, 2004
Creator: Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas et al.
Object Type: Report
System: The UNT Digital Library
PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 65, RHIC SPIN COLLABORATION MEETINGS XXVII, XXX. (open access)

PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 65, RHIC SPIN COLLABORATION MEETINGS XXVII, XXX.

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Date: December 30, 2004
Creator: Ogawa, A.
Object Type: Article
System: The UNT Digital Library
Signal Analysis for Radiation Event Identification (open access)

Signal Analysis for Radiation Event Identification

The method of digitizing the scintillation output signals from a lithiated sol-gel based glass is described. The design considerations for using the lithiated scintillator for the detection of Special Nuclear Material (SNM) is presented.
Date: December 30, 2004
Creator: Wallace, Steven A.
Object Type: Report
System: The UNT Digital Library
Ab Initio No-Core Shell Model Calculations Using Realistic Two- and Three-Body Interactions (open access)

Ab Initio No-Core Shell Model Calculations Using Realistic Two- and Three-Body Interactions

There has been significant progress in the ab initio approaches to the structure of light nuclei. One such method is the ab initio no-core shell model (NCSM). Starting from realistic two- and three-nucleon interactions this method can predict low-lying levels in p-shell nuclei. In this contribution, we present a brief overview of the NCSM with examples of recent applications. We highlight our study of the parity inversion in {sup 11}Be, for which calculations were performed in basis spaces up to 9{Dirac_h}{Omega} (dimensions reaching 7 x 10{sup 8}). We also present our latest results for the p-shell nuclei using the Tucson-Melbourne TM three-nucleon interaction with several proposed parameter sets.
Date: November 30, 2004
Creator: Navratil, P; Ormand, W E; Forssen, C & Caurier, E
Object Type: Article
System: The UNT Digital Library
An Architectural Tour of BlueGene/L (open access)

An Architectural Tour of BlueGene/L

BlueGene/L is the next large supercomputer for the DOE ASC program. BlueGene/L will consist of 65,000 dual processor IBM PowerPC 440 processors, each with attached FPU. Several interconnect networks consisting of a full 3D torus, combining tree, barrier tree, and interrupt tree are used to maximize computing efficiency. The theoretical peak performance of the system is 360 Teraflops/s.
Date: November 30, 2004
Creator: Dossa, D
Object Type: Article
System: The UNT Digital Library
Carbon Sequestration on Surface Mine Lands (open access)

Carbon Sequestration on Surface Mine Lands

The first quarter of 2004 was dedicated to tree planting activities in two locations in Kentucky. During the first year of this project there was not available mine land to plant in the Hazard area, so 107 acres were planted in the Martin County mine location. This year 120 acres were planted in the Hazard area to compensate for the prior year and an additional 57 acres were planted on Peabody properties in western Kentucky. Additional sets of special plots were established on each of these areas that contained 4800 seedlings each for carbon sequestration demonstrations. Plantings were also conducted to continue compaction and water quality studies on the newly established areas as well as continual measurements of the first year's plantings. Total plantings on this project now amount to 357 acres containing 245,960 seedlings. During the second quarter of this year monitoring systems were established for all the new research areas. Weather data pertinent to the research as well as hydrology and water quality monitoring continues to be conducted on all areas. Studies established to assess specific questions pertaining to carbon flux and the invasion of the vegetation by small mammals are being quantified. Experimental practices initiated with this …
Date: November 30, 2004
Creator: Graves, Donald H.; Barton, Christopher; Koo, Bon Jun; Sweigard, Richard & Warner, Richard
Object Type: Report
System: The UNT Digital Library
Carbon Sequestration on Surface Mine Lands Quarterly Report (open access)

Carbon Sequestration on Surface Mine Lands Quarterly Report

A monitoring program to measure treatment effects on above ground, and below ground carbon and nitrogen pools for the planting areas is being conducted. The collection of soil and tissue samples from both the 2003 and 2004 plantings is complete and are currently being processed in the laboratory. Detailed studies have been initiated to address specific questions pertaining to carbon cycling. Examinations of decomposition and heterotropic respiration on carbon cycling in the reforestation plots were continued during this reporting period. A whole-tree harvesting method was employed to evaluate carbon accumulation as a function of time on the mined site. The trees were extracted from the sites and separated into the following components: foliage, stems, branches, and roots.
Date: November 30, 2004
Creator: Graves, Donald H.; Barton, Christopher; Sweigard, Richard & Warner, Richard
Object Type: Report
System: The UNT Digital Library
CHARACTERIZATION OF THE LOCAL TITANIUM ENVIRONMENT IN DOPED SODIUM ALUMINUM HYDRIDE USING X-RAY ADSORPTION SPECTROSCOPY. (open access)

CHARACTERIZATION OF THE LOCAL TITANIUM ENVIRONMENT IN DOPED SODIUM ALUMINUM HYDRIDE USING X-RAY ADSORPTION SPECTROSCOPY.

Ti K-edge x-ray absorption spectroscopy was used to explore the local titanium environment and valence in 2-4 mol% Ti-doped sodium alanate. An estimate of the oxidation state of the dopant, based upon known standards, revealed a zero-valent titanium atom. An analysis of the near-edge and extended fine structures indicates that the Ti does not enter substitutional or interstitial sites in the NaAlH{sub 4} lattice. Rather, the Ti is located on/near the surface and is coordinated by 10.2 {+-} 1 aluminum atoms with an interatomic distance of 2.82 {+-} 0.01 {angstrom}, similar to that of TiAl{sub 3}. The Fourier transformed EXAFS spectra reveals a lack of long-range order around the Ti dopant indicating that the Ti forms nano-clusters of TiAl{sub 3}. The similarity of the spectra in the hydrided and dehydrided samples suggests that the local Ti environment is nearly invariant during hydrogen cycling.
Date: November 30, 2004
Creator: Graetz, J.; Ignatov, A. Yu; Tyson, T. A.; Reilly, J. J. & Johnson, J.
Object Type: Article
System: The UNT Digital Library
CROSS-ROLL FLOW FORMING OF ODS ALLOY HEAT EXCHANGER TUBES FOR HOOP CREEP ENHANCEMENT (open access)

CROSS-ROLL FLOW FORMING OF ODS ALLOY HEAT EXCHANGER TUBES FOR HOOP CREEP ENHANCEMENT

Mechanically alloyed oxide dispersion strengthened (ODS) Fe-Cr-Al alloy thin walled tubes and sheets, produced via powder processing and consolidation methodologies, are promising materials for eventual use at temperatures up to 1200 C in the power generation industry, far above the temperature capabilities of conventional alloys. Target end-uses range from gas turbine combustor liners to high aspect ratio (L/D) heat exchanger tubes. Grain boundary creep processes at service temperatures, particularly those acting in the hoop direction, are the dominant failure mechanisms for such components. The processed microstructure of ODS alloys consists of high aspect ratio grains aligned parallel to the tube axis, a result of dominant axial metal flow which aligns the dispersoid particles and other impurities in the longitudinal direction. The dispersion distribution is unaltered on a micro scale by recrystallization thermal treatments, but the high aspect ratio grain shape typically obtained limits transverse grain spacing and consequently the hoop creep response. Improving hoop creep in ODS-alloy components will require understanding and manipulating the factors that control the recrystallization behavior, and represents a critical materials design and development challenge that must be overcome in order to fully exploit the potential of ODS alloys. The objectives of this program are to …
Date: November 30, 2004
Creator: Kad, Bimal K.
Object Type: Report
System: The UNT Digital Library
Desorption/Ionization Fluence Thresholds and Improved Mass Spectral Consistency Measured Using a Flattop Laser Profile in the Bioaerosol Mass Spectrometry of Single Bacillus Endospores (open access)

Desorption/Ionization Fluence Thresholds and Improved Mass Spectral Consistency Measured Using a Flattop Laser Profile in the Bioaerosol Mass Spectrometry of Single Bacillus Endospores

Bioaerosol mass spectrometry (BAMS) is being developed to analyze and identify biological aerosols in real-time. Mass spectra of individual Bacillus endospores were measured here with a bipolar aerosol time-of-flight mass spectrometer in which molecular desorption and ionization were produced using a single laser pulse from a Q-switched, frequency-quadrupled Nd:YAG laser that was modified to have an approximately flattop profile. The flattened laser profile allowed the minimum fluence required to desorb and ionize significant numbers of ions from single aerosol particles to be determined. For Bacillus spores this threshold had a mean value of approximately 1 nJ/{micro}m{sup 2} (0.1 J/cm{sup 2}). Thresholds for individual spores, however, could apparently deviate by 20% or more from the mean. Threshold distributions for clumps of MS2 bacteriophage and bovine serum albumin were subsequently determined. Finally, the flattened profile was observed to increase the reproducibility of single spore mass spectra. This is consistent with the general conclusions of our earlier paper on the fluence dependence of single spore mass spectra and is particularly significant because it is expected to enable more robust differentiation and identification of single bioaerosol particles.
Date: November 30, 2004
Creator: Steele, P T; Srivastava, A; Pitesky, M E; Fergenson, D P; Tobias, H J; Gard, E E et al.
Object Type: Article
System: The UNT Digital Library
Development of a Novel Tunable X-Ray Source for the RPI-LINAC (open access)

Development of a Novel Tunable X-Ray Source for the RPI-LINAC

This document summarizes the results of a three year effort to develop a parametric x-ray (PXR) source. The emphasis of this research was to demonstrate production of high yield monoenergetic x-rays. Production of PXR is accomplished by placing a crystal in a relativistic electron beam. The process was first demonstrated in 1985 in Russia. Numerous papers were written about the characteristics of PXR from both experimental and theoretical perspectives. The advantage of PXR over other monoenergetic x-ray sources is that it is produced at large angle relative to the electron beam and at high intensity. None of the previous work described in the literature capitalized on this effect to study what is required in order to generate an effective monoenergetic x-ray source that can be used for practical applications. The work summarized here describes the process done in order to optimize the PXR production process by selecting an appropriate crystal and the optimal conditions. The research focused on production of 18 keV x-rays which are suitable for mammography however the results are not limited to this application or energy range. We are the first group to demonstrate x-ray imaging using PXR. Such sources can improve current medical imaging modalities. More …
Date: November 30, 2004
Creator: Danon, Y. & Block, R. C.
Object Type: Report
System: The UNT Digital Library
Development of Improved Sorbents for Radiochemical Separations at the SRS (open access)

Development of Improved Sorbents for Radiochemical Separations at the SRS

High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 137}Cs, {sup 90}Sr and alpha-emitting radionuclides (i.e., actinides) prior to disposal. Separation processes planned at SRS include caustic side solvent extraction, for {sup 137}Cs removal, and ion exchange/sorption of {sup 90}Sr and alpha-emitting radionuclides with monosodium titanate (MST). The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes {sup 238}Pu, {sup 239}Pu and {sup 240}Pu. This paper describes results from a project to produce sorbents that exhibit increased removal kinetics and capacity for {sup 90}Sr and alpha-emitting radionuclides versus that of the baseline MST material. Testing indicated that MST samples prepared in the presence of organic-based templating agents showed limited improvements in performance compared to the baseline MST. We observed significantly improved plutonium and neptunium removal performance with MST samples prepared upon the addition of a proprietary reagent. The modified MST offers the possibility of increased throughput and reduced solids handling in waste processing facilities at the SRS.
Date: November 30, 2004
Creator: Hobbs, David T.; Nyman, M. D.; Tripathi, A.; Medvedev, D. & Clearfield, A.
Object Type: Article
System: The UNT Digital Library
Effective Operators in the NCSM Formalism (open access)

Effective Operators in the NCSM Formalism

No-core shell model (NCSM) calculations using ab initio effective interactions are very successful in reproducing the experimental nuclear spectra. While a great deal of work has been directed toward computing effective interactions from bare nucleon-nucleon (NN) and three-nucleon forces, less progress has been made in calculating the effective operators. Thus, except for the relative kinetic energy, the proton radius, and the NN pair density, all investigations have used bare operators. We apply the Lee-Suzuki procedure to general two-body operators, investigating the importance of the approximations involved. In particular we concentrate on the limitations of the two-body cluster approximation.
Date: November 30, 2004
Creator: Stetcu, I; Barrett, B R; Navratil, P & Vary, J P
Object Type: Article
System: The UNT Digital Library
Effective Operators Within the Ab Initio No-Core Shell Model (open access)

Effective Operators Within the Ab Initio No-Core Shell Model

We implement an effective operator formalism for general one- and two-body operators, obtaining results consistent with the no-core shell model (NCSM) wave functions. The Argonne V8' nucleon-nucleon potential was used in order to obtain realistic wave functions for {sup 4}He, {sup 6}Li and {sup 12}C. In the NCSM formalism, we compute electromagnetic properties using the two-body cluster approximation for the effective operators and obtain results which are sensitive to the range of the bare operator. To illuminate the dependence on the range, we employ a Gaussian two-body operator of variable range, finding weak renormalization of long range operators (e.g., quadrupole) in a fixed model space. This is understood in terms of the two-body cluster approximation which accounts mainly for short-range correlations. Consequently, short range operators, such as the relative kinetic energy, will be well renormalized in the two-body cluster approximation.
Date: November 30, 2004
Creator: Stetcu, I; Barrett, B R; Navratil, P & Vary, J P
Object Type: Article
System: The UNT Digital Library
Effects of Oxide Film on the Corrosion Resistance of Titanium Grade 7 in Fluoride-Containing NaCl Brines (open access)

Effects of Oxide Film on the Corrosion Resistance of Titanium Grade 7 in Fluoride-Containing NaCl Brines

The effects of oxide film on the corrosion behavior of Titanium Grade 7 (0.12-0.25% Pd) in fluoride-containing NaCl brines have been investigated. With the presence of a 0.6 {micro}m thick oxide layer, the annealed Ti grade 7 exhibited a significant improvement on the anodic polarization behavior. However, the oxide film did not demonstrate sustainable corrosion resistance in fluoride-containing solutions.
Date: November 30, 2004
Creator: Lian, T; Whalen, M T & Wong, L
Object Type: Article
System: The UNT Digital Library
Energy Efficiency of the 2000 International Energy Conservation Code in West Virginia (open access)

Energy Efficiency of the 2000 International Energy Conservation Code in West Virginia

The West Virginia State Building Code contains two options for energy efficiency requirements in one- and two-family dwellings. One is the International Code Council?s (ICC) 2000 International Energy Conservation Code (IECC) (ICC 1999a,b) (87-4-4.1.6). The second is an exception (replacement) for Chapter 11 of the ICC International Residential Code (IRC) (87-4-4.1.7). The West Virginia Energy Efficiency Program, West Virginia Development Office, has asked the U.S. Department of Energy (DOE) to compare the energy use resulting from the application of the 2000 IECC code and the IRC code, as amended by West Virginia. The Department's Pacific Northwest National Laboratory (PNNL) compared the energy use from compliance with the 2000 IECC to the exception to Chapter 11 of the IRC known as the ''Alternate Energy Code''.
Date: November 30, 2004
Creator: Lucas, Robert G.
Object Type: Report
System: The UNT Digital Library
Estimating Terrorist Risk with Possibility Theory (open access)

Estimating Terrorist Risk with Possibility Theory

This report summarizes techniques that use possibility theory to estimate the risk of terrorist acts. These techniques were developed under the sponsorship of the Department of Homeland Security (DHS) as part of the National Infrastructure Simulation Analysis Center (NISAC) project. The techniques have been used to estimate the risk of various terrorist scenarios to support NISAC analyses during 2004. The techniques are based on the Logic Evolved Decision (LED) methodology developed over the past few years by Terry Bott and Steve Eisenhawer at LANL. [LED] The LED methodology involves the use of fuzzy sets, possibility theory, and approximate reasoning. LED captures the uncertainty due to vagueness and imprecision that is inherent in the fidelity of the information available for terrorist acts; probability theory cannot capture these uncertainties. This report does not address the philosophy supporting the development of nonprobabilistic approaches, and it does not discuss possibility theory in detail. The references provide a detailed discussion of these subjects. [Shafer] [Klir and Yuan] [Dubois and Prade] Suffice to say that these approaches were developed to address types of uncertainty that cannot be addressed by a probability measure. An earlier report discussed in detail the problems with using a probability measure to …
Date: November 30, 2004
Creator: Darby, J.L.
Object Type: Report
System: The UNT Digital Library
FIELD TESTING & OPTIMIZATION OF CO2/SAND FRACTURING TECHNOLOGY (open access)

FIELD TESTING & OPTIMIZATION OF CO2/SAND FRACTURING TECHNOLOGY

These contract efforts involved the demonstration of a unique liquid free stimulation technology which was, at the beginning of these efforts, in 1993 unavailable in the US. The process had been developed, and patented in Canada in 1981, and held promise for stimulating liquid sensitive reservoirs in the US. The technology differs from that conventionally used in that liquid carbon dioxide (CO{sub 2}), instead of water is the base fluid. The CO{sub 2} is pumped as a liquid and then vaporizes at reservoir conditions, and because no other liquids or chemicals are used, a liquid free fracture is created. The process requires a specialized closed system blender to mix the liquid CO{sub 2} with proppant under pressure. These efforts were funded to consist of up to 21 cost-shared stimulation events. Because of the vagaries of CO{sub 2} supplies, service company support and operator interest only 19 stimulation events were performed in Montana, New Mexico, and Texas. Final reports have been prepared for each of the four demonstration groups, and the specifics of those demonstrations are summarized. A summary of the demonstrations of a novel liquid-free stimulation process which was performed in four groups of ''Candidate Wells'' situated in Crockett Co., …
Date: November 30, 2004
Creator: Mazza, Raymond L.
Object Type: Report
System: The UNT Digital Library
FINAL REPORT UFP RESTART AND SPARGER TESTING (open access)

FINAL REPORT UFP RESTART AND SPARGER TESTING

Following a Design Basis Event (DBE), potential plugging of the PJM systems is highly probable after air compressors and/or electric power become unavailable for up to 100 hrs. Under such conditions, the rheologically bounding yield stress of the pretreated sludge simulant could reach 300-625 Pa. (Defined in WTP-RPP-100, Rev. 0, Sec. 6.1. [1] and WTP-RPP-98, Rev. 0, Secs. 5.1 and 5.2 [2].) The tests covered under this report are conservative since this range of bounding yield stress is based on the settled solids component in the tank. Also, note that CCN 065607 states that the design basis is 70 Pa for 'gelled material' over the entire tank. Three issues must be addressed by these tests: (1) Determine the required pressure and air flow to overcome the plugged sparger tube resistance following a DBE event. (2) Can the UFP PJMs be restarted with or without assistance from air spargers? (3) Show that solids can be mixed by air spargers following a DBE to allow generated hydrogen gas to rise and be vented to the vessel head space. This is to limit hydrogen concentrations below LFL level. In the first test, a full-scale sparger was simulated by a 2-inch dia. Schedule 160 …
Date: November 30, 2004
Creator: Guerrero, H & Michael Restivo, M
Object Type: Report
System: The UNT Digital Library
Final Technical Report (open access)

Final Technical Report

The objective of the research is the reduction of emissions of NOx and carbon from wood waste combustion and dryer systems. Focus in on suspension (dust) burners, especially the cyclone burners that are widely used in the industry. Computational fluid dynamics (CFD) is used to help understand the details of combustion and pollutant formation in wood waste combustion systems, and to help determine the potential of combustion modification for reducing emissions. Field burners are examined with the modeling.
Date: November 30, 2004
Creator: Malte, Philip
Object Type: Report
System: The UNT Digital Library
Final Technical Report (open access)

Final Technical Report

The Net100 project was motivated by complaints from computational scientists and researchers at DOE laboratories who were frequently unable to transfer data across the country at appropriate available bandwidth rates. Many high-performance distributed computing applications transfer large volumes of data over wide area networks and require data rates on the order of gigabits per second. Even though Internet backbone speeds have increased considerably in recent years, distributed applications are rarely able to take full advantage of these new high-capacity networks. The goal of the Net100 project was to try to improve the network performance of scientific applications without requiring the intervention of a network expert. The main objective was to have the operating system dynamically tune network flows so the application and the scientist would not have to be network-aware. The Net100 project sought to accomplish this by augmenting the tools and technology developed as a part of the NSF-sponsored Web100 project.
Date: November 30, 2004
Creator: Brown, Janet; Huntoon, Gwendolyn & Mathis, Matthew
Object Type: Report
System: The UNT Digital Library
FY04-Q4 REPORT: LX-17 MODELING (open access)

FY04-Q4 REPORT: LX-17 MODELING

TATB containing explosives tend to permanently expand as their temperatures are increased or thermally cycled, a phenomenon known as ''ratchet-growth.'' Mesoscale simulations using dissipative particle dynamics (DPD) have been carried out in order to study the geometric packing effects of TATB pressed powders under stress conditions. Further, our mesoscale simulations of polycrystalline TATB pressed powders have been used to predict hot-spot changes as a function of temperature (thermal cycling) and confinement. Our DPD simulations showed irreversible permanent growth in the mesoscale pressed powders only when crystal fracture induced by the anisotropic thermal expansion of TATB was incorporated into the model.
Date: November 30, 2004
Creator: Gee, R & Fried, L
Object Type: Report
System: The UNT Digital Library
Generation of angular-momentum-dominated electron beams from a photoinjector (open access)

Generation of angular-momentum-dominated electron beams from a photoinjector

Various projects under study require an angular-momentum-dominated electron beam generated by a photoinjector. Some of the proposals directly use the angular-momentum-dominated beams (e.g. electron cooling of heavy ions), while others require the beam to be transformed into a flat beam (e.g. possible electron injectors for light sources and linear colliders). In this paper, we report our experimental study of an angular-momentum-dominated beam produced in a photoinjector, addressing the dependencies of angular momentum on initial conditions. We also briefly discuss the removal of angular momentum. The results of the experiment, carried out at the Fermilab/NICADD Photoinjector Laboratory, are found to be in good agreement with theoretical and numerical models.
Date: November 30, 2004
Creator: Sun, Yin-E.; Piot, Philippe; Kim, Kwang-Je; Barov, Nikolas; Lidia, Steven; Santucci, James et al.
Object Type: Article
System: The UNT Digital Library