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Transforming CyberSecurity R&D within the Department of Energy: Getting Ahead of The Threat
This report outlines a preliminary response from DOE researchers to the following three questions: a) what are the key priorities w.r.t. cybersecurity R&D over the next decade? b) what would we recommend, in terms of a program, to address those priorities c) how would a DOE Office of Science program in this area complement other cybersecurity R&D initiatives such as NSF's or other agency programs?
Date:
January 1, 2008
Creator:
Frincke, Deborah A.; Catlett, Charlie; Siebenlist, Frank; Strelitz, Richard; Talbot, Ed & Worley, Brian
Object Type:
Report
System:
The UNT Digital Library
Transmutation Fuel Campaign Description and Status
This report contains a technical summary package in response to a Level 2 milestone in the transmutation fuel campaign (TFC) management work-package calling for input to the Secretarial decision. At present, the form of the Secretarial decision package is not fully defined, and it is not clear exactly what will be required from the TFC as a final input. However, it is anticipated that a series oftechnical and programmatic documents will need to be provided in support of a wider encompassing document on GNEP technology development activities. The TFC technical leadership team provides this report as initial input to the secretarial decision package which is being developed by the Technical Integration Office (TIO) in support of Secretarial decision. This report contains a summary of the TFC execution plan with a work breakdown structure, highlevel schedule, major milestones, and summary description of critical activities in support of campaign objectives. Supporting documents referenced in this report but provided under separate cover include: • An updated review of the state-of-the art for transmutation fuel development activities considering national as well as international fuel research and development testing activities. • A definition of the Technology Readiness Level (TRL) used to systematically define and execute …
Date:
January 1, 2008
Creator:
Carmack, Jon & Pasamehmetoglu, Kemal O.
Object Type:
Report
System:
The UNT Digital Library
Transport anisotropy as a probe of the interstitial vortex state in superconductors with artificial pinning arrays
We show using simulations that when interstitial vortices are present in superconductors with periodic pinning arrays, the transport in two perpendicular directions can be anisotropic. The degree of the anisotropy varies as a function of field due to the fact that the interstitial vortex lattice has distinct orderings at different matching fields. The anisotropy is most pronounced at the matching fields but persists at incommensurate fields, and it is most prominent for triangular, honeycomb, and kagome pinning arrays. Square pinning arrays can also show anisotropic transport at certain fields in spite of the fact that the perpendicular directions of the square pinning array are identical. We show that the anisotropy results from distinct vortex dynamical states and that although the critical depinning force may be lower in one direction, the vortex velocity above depinning may also be lower in the same direction for ranges of external drives where both directions are depinned. For honeycomb and kagome pinning arrays, the anisotropy can show multiple reversals as a function of field. We argue that when the pinning sites can be multiply occupied such that no interstitial vortices are present, the anisotropy is strongly reduced or absent.
Date:
January 1, 2008
Creator:
Reichhardt, Charles & Reichhardt, Cynthia
Object Type:
Article
System:
The UNT Digital Library
TRU waste inventory collection and work off plans for the centralization of TRU waste characterization/certification at INL - on your mark - get set - 9410
The U.S. Department of Energy (DOE) amended the Record of Decision (ROD) for the Waste Management Program: Treatment and Storage of Transuranic Waste to centralize transuranic (TRU) waste characterization/certification from fourteen TRU waste sites. This centralization will allow for treatment, characterization and certification ofTRU waste from the fourteen sites, thirteen of which are sites with small quantities ofTRU waste, at the Idaho National Laboratory (INL) prior to shipping the waste to the Waste Isolation Pilot Plant (WIPP) for disposal. Centralization of this TRU waste will avoid the cost of building treatment, characterization, certification, and shipping capabilities at each of the small quantity sites that currently do not have existing facilities. Advanced Mixed Waste Treatment Project (AMWTP) and Idaho Nuclear Technology and Engineering Center (INTEC) will provide centralized shipping facilities, to WIPP, for all of the small quantity sites. Hanford, the one large quantity site identified in the ROD, has a large number of waste in containers that are overpacked into larger containers which are inefficient for shipment to and disposal at WIPP. The AMWTF at the INL will reduce the volume of much of the CH waste and make it much more efficient to ship and dispose of at WIPP. …
Date:
January 1, 2008
Creator:
Mctaggert, Jerri Lynne; Lott, Sheila A & Gadbury, Casey
Object Type:
Article
System:
The UNT Digital Library
Tuning magnetic frustration on the diamond lattice of the A-site magnetic spinels CoA12-xGax04: lattice expansion versus site disorder
The spinels CoB{sub 2}O{sub 4} with magnetic Co{sup 2+} ions on the diamond lattice A site can be frustrated because of competing near-neighbor (J{sub 1}) and next-near neighbor (J{sub 2}) interactions. Here we describe attempts to tune the relative strengths of these interactions by substitution on the non-magnetic B-site. The system we employ is CoAl{sub 2-x}Ga{sub x}O{sub 4}, where Al is systematically replaced by the larger Ga, ostensibly on the B site. As expected, Ga substitution expands the lattice, resulting in Co atoms on the A-site being pushed further from one other and thereby weakening magnetic interactions. In addition, Ga distributes between the B and the A site in a concentration dependent manner displacing an increasing amount of Co from the A site with increasing x. This increased inversion, which is confirmed by neutron diffraction studies carried out at room temperature, affects magnetic ordering very significantly, and changes the nature of the ground state. Modeling of the magnetic coupling illustrates the complexity that arises from the cation site disorder.
Date:
January 1, 2008
Creator:
Proffen, Thomas E; Melot, Brent C; Page, Katharine; Seshadri, Ramzy; Stoudenmire, E M; Balents, Leon et al.
Object Type:
Article
System:
The UNT Digital Library
Ultraviolet Induced Motion of a Fluorescent Dust Cloud in an Argon Direct Current Glow Discharge Plasma
Dusty plasmas consist of electrons, ions, neutrals and nm-μm sized particles commonly referred to as dust. In man-made plasmas this dust may represent impurities in a tokamak or plasma etching processing. In astrophysical plasmas this dust forms structures such as planetary rings and comet tails. To study dusty plasma dynamics an experiment was designed in which a 3:1 silica (<5 μm diameter) and fl uorescent dust mixture was added to an argon DC glow discharge plasma and exposed to UV radiation. This fl uorescent lighting technique offers an advantage over laser scattering (which only allows two-dimensional slices of the cloud to be observed) and is simpler than scanning mirror techniques or particle image velocimetry. Under typical parameters (P=150 mTorr, V anode= 100 V, Vcathode= -400 V, Itotal < 2mA) when the cloud is exposed to the UV light (100W, λ = 365 nm) the mixture fl uoresces, moves ~2mm towards the light source and begins rotating in a clockwise manner (as seen from the cathode). By calibrating a UV lamp and adjusting the relative intensity of the UV with a variable transformer it was found that both translational and rotational velocities are a function of UV intensity. Additionally, it was …
Date:
January 1, 2008
Creator:
Hvasta, M.G. & and Zwicker, A.
Object Type:
Article
System:
The UNT Digital Library
Uncorrelated versus independent elliptically-contoured distributions for anomalous change detection in hyperspectral imagery
The detection of actual changes in a pair of images is confounded by the inadvertent but pervasive differences that inevitably arise whenever two pictures are taken of the same scene, but at different times and under different conditions. These differences include effects due to illumination, calibration, misregistration, etc. If the actual changes are assumed to be rare, then one can 'learn' what the pervasive differences are, and can identify the deviations from this pattern as the anomalous changes. A recently proposed framework for anomalous change detection recasts the problem as one of binary classification between pixel pairs in the data and pixel pairs that are independently chosen from the two images. When an elliptically-contoured (EC) distribution is assumed for the data, then analytical expressions can be derived for the measure of anomalousness of change. However, these expression are only available for a limited class of EC distributions. By replacing independent pixel pairs with uncorrelated pixel pairs, an approximate solution can be found for a much broader class of EC distributions. The performance of this approximation is investigated analytically and empirically, and includes experiments comparing the detection of real changes in real data.
Date:
January 1, 2008
Creator:
Theiler, James P & Scovel, James C
Object Type:
Article
System:
The UNT Digital Library
Using ancillary information to improve hypocenter estimation: Bayesian single event location (BSEL)
We have developed and tested an algorithm, Bayesian Single Event Location (BSEL), for estimating the location of a seismic event. The main driver for our research is the inadequate representation of ancillary information in the hypocenter estimation procedure. The added benefit is that we have also addressed instability issues often encountered with historical NLR solvers (e.g., non-convergence or seismically infeasible results). BSEL differs from established nonlinear regression techniques by using a Bayesian prior probability density function (prior PDF) to incorporate ancillary physical basis constraints about event location. P-wave arrival times from seismic events are used in the development. Depth, a focus of this paper, may be modeled with a prior PDF (potentially skewed) that captures physical basis bounds from surface wave observations. This PDF is constructed from a Rayleigh wave depth excitation eigenfunction that is based on the observed minimum period from a spectrogram analysis and estimated near-source elastic parameters. For example, if the surface wave is an Rg phase, it potentially provides a strong constraint for depth, which has important implications for remote monitoring of nuclear explosions. The proposed Bayesian algorithm is illustrated with events that demonstrate its congruity with established hypocenter estimation methods and its application potential. The …
Date:
January 1, 2008
Creator:
Anderson, Dale N
Object Type:
Article
System:
The UNT Digital Library
Using Helicopter Electromagnetic Surveys to Identify Potential Hazards at Mine Waste Impoundments
In July 2003, helicopter electromagnetic surveys were conducted at 14 coal waste impoundments in southern West Virginia. The purpose of the surveys was to detect conditions that could lead to impoundment failure either by structural failure of the embankment or by the flooding of adjacent or underlying mine works. Specifically, the surveys attempted to: 1) identify saturated zones within the mine waste, 2) delineate filtrate flow paths through the embankment or into adjacent strata and receiving streams, and 3) identify flooded mine workings underlying or adjacent to the waste impoundment. Data from the helicopter surveys were processed to generate conductivity/depth images. Conductivity/depth images were then spatially linked to georeferenced air photos or topographic maps for interpretation. Conductivity/depth images were found to provide a snapshot of the hydrologic conditions that exist within the impoundment. This information can be used to predict potential areas of failure within the embankment because of its ability to image the phreatic zone. Also, the electromagnetic survey can identify areas of unconsolidated slurry in the decant basin and beneath the embankment. Although shallow, flooded mineworks beneath the impoundment were identified by this survey, it cannot be assumed that electromagnetic surveys can detect all underlying mines. A preliminary …
Date:
January 1, 2008
Creator:
Hammack, R. W.
Object Type:
Article
System:
The UNT Digital Library
Utility-Interconnected Photovoltaic Systems: Evaluating the Rationale for the Utility-Accessible External Disconnect Switch
The utility-accessible alternating current (AC) external disconnect switch (EDS) for distributed generators, including photovoltaic (PV) systems, is a hardware feature that allows a utility?s employees to manually disconnect a customer-owned generator from the electricity grid. This paper examines the utility-accessible EDS debate in the context of utility-interactive PV systems for residential and small commercial installations. It also evaluates the rationale for EDS requirements.
Date:
January 1, 2008
Creator:
Coddington, M.; Margolis, R.M. & Aabakken, J.
Object Type:
Report
System:
The UNT Digital Library
Vehicle Ancillary Load Reduction Project Close-Out Report: An Overview of the Task and a Compilation of the Research Results
The amount of fuel used for climate control in U.S. vehicles reduces the fuel economy of more than 200 million light-duty conventional vehicles and thus affects U.S. energy security. Researchers at the DOE National Renewable Energy Laboratory estimated that the United States consumes about 7 billion gallons of fuel per year for air-conditioning (A/C) light-duty vehicles. Using a variety of tools, NREL researchers developed innovative techniques and technologies to reduce the amount of fuel needed for these vehicles' ancillary loads. For example, they found that the A/C cooling capacity of 5.7 kW in a Cadillac STS could be reduced by 30% while maintaining a cooldown performance of 30 minutes. A simulation showed that reducing the A/C load by 30% decreased A/C fuel consumption by 26%. Other simulations supported the great potential for improving fuel economy by using new technologies and techniques developed to reduce ancillary loads.
Date:
January 1, 2008
Creator:
Rugh, J. & Farrington, R.
Object Type:
Report
System:
The UNT Digital Library
Verification of MELCOR Input Decks Used in ITER RPrS Analyses
This report as part of an ITER Task Agreement, documents the verification of the MELCOR Input Computer Decks used in performing the required safety analyses to be presented in the Preliminary Safety Report (Rapport Préliminaire de Séreté, RPrS).
Date:
January 1, 2008
Creator:
Moore, Richard L.
Object Type:
Report
System:
The UNT Digital Library
Vibration suppression in cutting tools using collocated piezoelectric sensors/actuators with an adaptive control algorithm
The machining process is very important in many engineering applications. In high precision machining, surface finish is strongly correlated with vibrations and the dynamic interactions between the part and the cutting tool. Parameters affecting these vibrations and dynamic interactions, such as spindle speed, cut depth, feed rate, and the part's material properties can vary in real-time, resulting in unexpected or undesirable effects on the surface finish of the machining product. The focus of this research is the development of an improved machining process through the use of active vibration damping. The tool holder employs a high bandwidth piezoelectric actuator with an adaptive positive position feedback control algorithm for vibration and chatter suppression. In addition, instead of using external sensors, the proposed approach investigates the use of a collocated piezoelectric sensor for measuring the dynamic responses from machining processes. The performance of this method is evaluated by comparing the surface finishes obtained with active vibration control versus baseline uncontrolled cuts. Considerable improvement in surface finish (up to 50%) was observed for applications in modern day machining.
Date:
January 1, 2008
Creator:
Radecki, Peter P; Farinholt, Kevin M; Park, Gyuhae & Bement, Matthew T
Object Type:
Article
System:
The UNT Digital Library
Virtual Human Problem Solving Environments
Abstract. Interest in complex integrated digital or virtual human modeling has seen a significant increase over the last decade. Coincident with that increased interest, Oak Ridge National Laboratory (ORNL) initiated the development of a human simulation tool, the Virtual Human. The Virtual Human includes a problem-solving environment (PSE) for implementing the integration of physiological models in different programming languages and connecting physiological function to anatomy. The Virtual Human PSE (VHPSE) provides the computational framework with which to develop the concept of a "Virtual Human." Supporting the framework is a data definition for modeling parameters, PhysioML, a Virtual Human Database (VHDB), and a Web-based graphical user interface (GUI) developed using Java. Following description of the VHPSE, we discuss four example implementations of models within the framework. Further expansion of a human modeling environment was carried out in the Defense Advanced Research Projects Agency Virtual Soldier Project. SCIRun served as the Virtual Soldier problem solving environment (VSPSE). We review and compare specific developments in these projects that have significant potential for the future of Virtual Human modeling and simulation. We conclude with an evaluation of areas of future work that will provide important extensions to the VHPSE and VSPSE and make possible …
Date:
January 1, 2008
Creator:
Ward, Richard C.; Pouchard, Line Catherine; Munro, Nancy B. & Fischer, Sarah Kathleen
Object Type:
Book
System:
The UNT Digital Library
Vortices wiggled and dragged
When a sufficiently strong magnetic field is applied to a superconductor, some of the field can pierce it through the generation of magnetic vortices, each of which contains a quantized amount of magnetic flux. Although the superconducting state of the material outside each vortex is maintained (and destroyed within each vortex), the interaction of vortices with a current passing through the material can cause them to move, dissipating energy and thereby generating a source of electrical resistance. The ability to manipulate an individual superconducting vortex represents a powerful tool for studying the dynamics of vortices and the superconductors that support them. It could also lead to the development of a new class of fluxon-based electronics.
Date:
January 1, 2008
Creator:
Reichhardt, Charles
Object Type:
Article
System:
The UNT Digital Library
When superfluids are a drag
The article considers the dramatic phenomenon of seemingly frictionless flow of slow-moving superfluids. Specifically the question of whether an object in a superfluid flow experiences any drag force is addressed. A brief account is given of the history of this problem and it is argued that recent advances in ultracold atomic physics can shed much new light on this problem. The article presents the commonly held notion that sufficiently slow-moving superfluids can flow without drag and also discusses research suggesting that scattering quantum fluctuations might cause drag in a superfluid moving at any speed.
Date:
January 1, 2008
Creator:
Roberts, David C
Object Type:
Article
System:
The UNT Digital Library
World average top-quark mass
This paper summarizes a talk given at the Top2008 Workshop at La Biodola, Isola d Elba, Italy. The status of the world average top-quark mass is discussed. Some comments about the challanges facing the experiments in order to further improve the precision are offered.
Date:
January 1, 2008
Creator:
Glenzinski, D.
Object Type:
Article
System:
The UNT Digital Library
X-Ray Absorption Spectroscopy of Yb3+-Doped Optical Fibers
Optical fibers doped with Ytterbium-3+ have become increasingly common in fiber lasers and amplifiers. Yb-doped fibers provide the capability to produce high power and short pulses at specific wavelengths, resulting in highly effective gain media. However, little is known about the local structure, distribution, and chemical coordination of Yb3+ in the fibers. This information is necessary to improve the manufacturing process and optical qualities of the fibers. Five fibers doped with Yb3+ were studied using Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy and X-ray Absorption Near Edge Spectroscopy (XANES), in addition to Yb3+ mapping. The Yb3+ distribution in each fiber core was mapped with 2D and 1D intensity scans, which measured X-ray fluorescence over the scan areas. Two of the five fibers examined showed highly irregular Yb3+ distributions in the core center. In four of the five fibers Yb3+ was detected outside of the given fiber core dimensions, suggesting possible Yb3+ diffusion from the core, manufacturing error, or both. X-ray absorption spectroscopy (XAS) analysis has so far proven inconclusive, but did show that the fibers had differing EXAFS spectra. The Yb3+ distribution mapping proved highly useful, but additional modeling and examination of fiber preforms must be conducted to improve XAS …
Date:
January 1, 2008
Creator:
Citron, Robert & Kropf, A. Jeremy
Object Type:
Article
System:
The UNT Digital Library
X-ray line polarization spectroscopy of Li-like satellite line spectra
We apply the magnetic-sublevel atomic kinetics model POLAR to the calculation of polarization properties of satellite lines in Li-like Si driven by subpicosecond-duration laser pulses. We identify spectral lines whose polarization can serve as a marker of plasma anisotropy due to anisotropy in the electron distribution function. We also discuss the utility and limitations of ur current theoretical approach and point out possible future improvements and directions.
Date:
January 1, 2008
Creator:
Sherrill, Manolo Edgar; Abdallah, Joseph; Zhang, Honglin; Hakel, Peter & Mancini, Roberto C
Object Type:
Article
System:
The UNT Digital Library
Zirconium Oxide Nanostructures Prepared by Anodic Oxidation
Zirconium oxide is an advanced ceramic material highly useful for structural and electrical applications because of its high strength, fracture toughness, chemical and thermal stability, and biocompatibility. If highly-ordered porous zirconium oxide membranes can be successfully formed, this will expand its real-world applications, such as further enhancing solid-oxide fuel cell technology. Recent studies have achieved various morphologies of porous zirconium oxide via anodization, but they have yet to create a porous layer where nanoholes are formed in a highly ordered array. In this study, electrochemical methods were used for zirconium oxide synthesis due to its advantages over other coating techniques, and because the thickness and morphology of the ceramic fi lms can be easily tuned by the electrochemical parameters, such as electrolyte solutions and processing conditions, such as pH, voltage, and duration. The effects of additional steps such as pre-annealing and post-annealing were also examined. Results demonstrate the formation of anodic porous zirconium oxide with diverse morphologies, such as sponge-like layers, porous arrays with nanoholes ranging from 40 to 75 nm, and nanotube layers. X-ray powder diffraction analysis indicates a cubic crystallographic structure in the zirconium oxide. It was noted that increased voltage improved the ability of the membrane to …
Date:
January 1, 2008
Creator:
Dang, Y. Y.; Bhuiyan, M.S. & Paranthaman, M. P.
Object Type:
Article
System:
The UNT Digital Library