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631 Matching Results
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The Large Synoptic Survey Telescope and Foundations for Data Exploitation of Petabyte Data Sets
The next generation of imaging surveys in astronomy, such as the Large Synoptic Survey Telescope (LSST), will require multigigapixel cameras that can process enormous amounts of data read out every few seconds. This huge increase in data throughput (compared to megapixel cameras and minute- to hour-long integrations of today's instruments) calls for a new paradigm for extracting the knowledge content. We have developed foundations for this new approach. In this project, we have studied the necessary processes for extracting information from large time-domain databases systematics. In the process, we have produced significant scientific breakthroughs by developing new methods to probe both the elusive time and spatial variations in astrophysics data sets from the SuperMACHO (Massive Compact Halo Objects) survey, the Lowell Observatory Near-Earth Object Search (LONEOS), and the Taiwanese American Occultation Survey (TAOS). This project continues to contribute to the development of the scientific foundations for future wide-field, time-domain surveys. Our algorithm and pipeline development has provided the building blocks for the development of the LSST science software system. Our database design and performance measures have helped to size and constrain LSST database design. LLNL made significant contributions to the foundations of the LSST, which has applications for large-scale imaging …
Date:
February 26, 2007
Creator:
Cook, K H; Nikolaev, S & Huber, M E
Object Type:
Report
System:
The UNT Digital Library
Creating the Core Conditions of Extra-solar and Solar Giant Planets
Materials can be experimentally characterized at high pressures and densities by sending a laser-induced shock wave through a sample that is pre-compressed inside a diamond-anvil cell. This combination of static- and dynamic-compression methods has been experimentally demonstrated, and ultimately provides access to the 10-100 TPa (0.1-1 Gbar) pressure range that is relevant to planetary science. We report on dynamical measurements of the high pressure compressibility of helium, hydrogen and helium/hydrogen mixtures up to 230 GPa by combining laser shocks and static compression in diamond anvil cells. The initial density of samples in these precompressed targets has been varied by a factor of 3. The measurements on the principal He Hugoniot, i.e with the initial density of cryo-helium, is extended above 100 GPa and a maximum of compression ratio of greater than 5-fold of the initial density is observed. Also, a strong decrease in compressibility is observed by increasing the initial density. A similar data set has been produced for precompressed H{sub 2} and a mixture of He and H{sub 2}.
Date:
February 26, 2007
Creator:
Celliers, P.; Eggert, J.; Collins, G.; Brygoo, S.; Jeanloz, R.; McWilliams, R. et al.
Object Type:
Report
System:
The UNT Digital Library
A Hypothesis of the Magnetostatic Turbulence and its Implications for Astrophysics
Arguments are presented in favor of a possible existence of a random, force-free magnetic field. Ponderomotive forces in such a field are small, and the evolutionary time is much longer than Alfven crossing time over the vortex scale, whence the suggested term ''magnetostatic''. The presence of this long-lived random magnetic field provides stiffness with respect to large-scale compressional motions. On the other hand, such a field cannot be detected by techniques involving line-of-sight averaging. It may therefore be a source of stiffness for various astrophysical objects, ranging from plasmas in clusters of galaxies to the interiors of molecular clouds in HII regions, and remaining at the same time undetectable. Analysis of large-scale motions on the background of the magnetostatic turbulence is presented; it is concluded that these large-scale motions can be roughly described by a usual hydrodynamics for the matter with an isotropic pressure; the adiabatic index is 4/3.
Date:
February 26, 2007
Creator:
Ryutov, D. D. & Remington, B. A.
Object Type:
Article
System:
The UNT Digital Library
Terahop and Lawrence Livermore National LaboratoryStructural Fire RF Testing
The Georgia Public Safety Training Center's Live Fire Training Facility in Forsyth, GA is a three story structure constructed of rebar-reinforced concrete wall and floors. All the door and window coverings on the building are constructed of thick, plate metal to withstand the high temperatures generated inside the building during training exercises. All of the building's walls and floors are 1-foot thick, and regular concrete columns run up along the inside of the wall increasing the thickness to 20-inches in those locations. A center concrete staircase divides the structure in half. For typical exercises, fires are started in the back right corner of the building on the first floor and in the front right corner on the second floor as shown in Figure 2. Due to the high heat generated during these exercises, measured at 300 F on the floor and 700 F near the ceilings, there were limited locations at which equipment could be placed that did not incorporate heat shielding, such as the Lawrence Livermore National Laboratory's UWB system. However, upon inspection of the building, two preferable locations were identified in which equipment could be placed that would be protected from the temperature extremes generated by the fires. …
Date:
February 26, 2007
Creator:
Haugen, P & Pratt, G
Object Type:
Report
System:
The UNT Digital Library
RAPID ANALYSIS OF EMERGENCY URINE AND WATER SAMPLES
There is a need for fast, reliable methods for the determination of actinides and Sr-89/90 analysis on environmental and bioassay samples in response to an emergency radiological incident. The SRS (Savannah River Site) Environmental Bioassay Laboratory participated in the National Institute of Standards and Technology Radiochemistry Intercomparison Program (NRIP-06) and analyzed water and urine samples within 8 hours of receipt. The SRS Environmental Laboratory was the only lab that participated in the program that analyzed these samples for both actinides and Sr-89/90 within the requested 8 hour turnaround time. A new, rapid actinide and strontium 89/90 separation method was used for both urine and water samples. This method uses stacked TEVA Resin{reg_sign}, TRU Resin{reg_sign} and Sr-Resin{reg_sign} cartridges from Eichrom Technologies (Darien, IL, USA) that allows the rapid separation of plutonium (Pu), neptunium (Np), uranium (U), and americium (Am), curium (Cm) and thorium (Th) using a single multi-stage column combined with alpha spectrometry. By using vacuum box cartridge technology and stacked cartridges with rapid flow rates, sample preparation time was minimized. This paper discusses the technology and conditions employed for both water and urine samples and presents the SRS performance data on the NRIP-06 samples.
Date:
February 26, 2007
Creator:
Maxwell, S
Object Type:
Article
System:
The UNT Digital Library
HYDROGEN TECHNOLOGY RESEARCH AT THE SAVANNAH RIVER NATIONAL LABORATORY, CENTER FOR HYDROGEN RESEARCH, AND THE HYDROGEN TECHNOLOGY RESEARCH LABORATORY
The Savannah River National Laboratory (SRNL) is a U.S. Department of Energy research and development laboratory located at the Savannah River Site (SRS) near Aiken, South Carolina. SRNL has over 50 years of experience in developing and applying hydrogen technology, both through its national defense activities as well as through its recent activities with the DOE Hydrogen Programs. The hydrogen technical staff at SRNL comprises over 90 scientists, engineers and technologists, and it is believed to be the largest such staff in the U.S. SRNL has ongoing R&D initiatives in a variety of hydrogen storage areas, including metal hydrides, complex hydrides, chemical hydrides and carbon nanotubes. SRNL has over 25 years of experience in metal hydrides and solid-state hydrogen storage research, development and demonstration. As part of its defense mission at SRS, SRNL developed, designed, demonstrated and provides ongoing technical support for the largest hydrogen processing facility in the world based on the integrated use of metal hydrides for hydrogen storage, separation and compression. The SRNL has been active in teaming with academic and industrial partners to advance hydrogen technology. A primary focus of SRNL's R&D has been hydrogen storage using metal and complex hydrides. SRNL and its Hydrogen Technology …
Date:
February 26, 2007
Creator:
Danko, E
Object Type:
Article
System:
The UNT Digital Library
Osiris: A Modern, High-Performance, Coupled, Multi-Physics Code For Nuclear Reactor Core Analysis
To meet the simulation needs of the GNEP program, LLNL is leveraging a suite of high-performance codes to be used in the development of a multi-physics tool for modeling nuclear reactor cores. The Osiris code project, which began last summer, is employing modern computational science techniques in the development of the individual physics modules and the coupling framework. Initial development is focused on coupling thermal-hydraulics and neutral-particle transport, while later phases of the project will add thermal-structural mechanics and isotope depletion. Osiris will be applicable to the design of existing and future reactor systems through the use of first-principles, coupled physics models with fine-scale spatial resolution in three dimensions and fine-scale particle-energy resolution. Our intent is to replace an existing set of legacy, serial codes which require significant approximations and assumptions, with an integrated, coupled code that permits the design of a reactor core using a first-principles physics approach on a wide range of computing platforms, including the world's most powerful parallel computers. A key research activity of this effort deals with the efficient and scalable coupling of physics modules which utilize rather disparate mesh topologies. Our approach allows each code module to use a mesh topology and resolution that …
Date:
February 26, 2007
Creator:
Procassini, R. J.; Chand, K. K.; Clouse, C. J.; Ferencz, R. M.; Grandy, J. M.; Henshaw, W. D. et al.
Object Type:
Article
System:
The UNT Digital Library
Reactive Membrane Barriers for Containment of Subsurface Contamination
The overall goal of this project was to develop reactive membrane barriers--a new and flexible technique to contain and stabilize subsurface contaminants. Polymer membranes will leak once a contaminant is able to diffuse through the membrane. By incorporating a reactive material in the polymer, however, the contaminant is degraded or immobilized within the membrane. These processes increase the time for contaminants to breakthrough the barrier (i.e. the lag time) and can dramatically extend barrier lifetimes. In this work, reactive barrier membranes containing zero-valent iron (Fe{sup 0}) or crystalline silicotitanate (CST) were developed to prevent the migration of chlorinated solvents and cesium-137, respectively. These studies were complemented by the development of models quantifying the leakage/kill time of reactive membranes and describing the behavior of products produced via the reactions within the membranes. First, poly(vinyl alcohol) (PVA) membranes containing Fe{sup 0} and CST were prepared and tested. Although PVA is not useful in practical applications, it allows experiments to be performed rapidly and the results to be compared to theory. For copper ions (Cu{sup 2+}) and carbon tetrachloride, the barrier was effective, increasing the time to breakthrough over 300 times. Even better performance was expected, and the percentage of the iron used …
Date:
February 26, 2007
Creator:
Arnold, William A. & Cussler, Edward L.
Object Type:
Report
System:
The UNT Digital Library
Development of a Prototype Lattice Boltzmann Code for CFD of Fusion Systems.
Designs of proposed fusion reactors, such as the ITER project, typically involve the use of liquid metals as coolants in components such as heat exchangers, which are generally subjected to strong magnetic fields. These fields induce electric currents in the fluids, resulting in magnetohydrodynamic (MHD) forces which have important effects on the flow. The objective of this SBIR project was to develop computational techniques based on recently developed lattice Boltzmann techniques for the simulation of these MHD flows and implement them in a computational fluid dynamics (CFD) code for the study of fluid flow systems encountered in fusion engineering. The code developed during this project, solves the lattice Boltzmann equation, which is a kinetic equation whose behaviour represents fluid motion. This is in contrast to most CFD codes which are based on finite difference/finite volume based solvers. The lattice Boltzmann method (LBM) is a relatively new approach which has a number of advantages compared with more conventional methods such as the SIMPLE or projection method algorithms that involve direct solution of the Navier-Stokes equations. These are that the LBM is very well suited to parallel processing, with almost linear scaling even for very large numbers of processors. Unlike other methods, …
Date:
February 26, 2007
Creator:
Pattison, Martin J; Premnath, Kannan N; Banerjee, Sanjoy & Dwivedi, Vinay
Object Type:
Report
System:
The UNT Digital Library
GRB 060714: No Clear Dividing Line Between Prompt Emission and X-Ray Flares
The long gamma-ray burst GRB 060714 was observed to exhibit a series of five X-ray flares beginning {approx} 70 s after the burst trigger T{sub 0} and continuing until {approx} T{sub 0} + 200 s. The first two flares were detected by the Burst Alert Telescope (BAT) on the Swift satellite, before Swift had slewed to the burst location, while the last three flares were strongly detected by the X-Ray Telescope (XRT) but only weakly detected by the BAT. This burst provides an unusual opportunity to track a complete sequence of flares over a wide energy range. The flares were very similar in their light curve morphology, showing power-law rise and fall components, and in most cases significant sub-structure. The flares also showed strong evolution with time, both spectrally and temporally. The small time scale and large amplitude variability observed are incompatible with an external shock origin for the flares, and support instead late time sporadic activity either of the central source or of localized dissipation events within the outflow. We show that the flares in GRB 060714 cannot be the result of internal shocks in which the contrast in the Lorentz factor of the colliding shells is very small, …
Date:
February 26, 2007
Creator:
Krimm, Hans A.; Granot, J.; Marshal, F.; Perri, M.; Barthelmy, S. D.; Burrows, D. N. et al.
Object Type:
Article
System:
The UNT Digital Library
A Liquid Xenon Ionization Chamber in an All-fluoropolymer Vessel
A novel technique has been developed to build vessels for liquid xenon ionization detectors entirely out of ultra-clean fluoropolymer. We describe the advantages in terms of low radioactivity contamination, provide some details of the construction techniques, and show the energy resolution achieved with a prototype all-fluoropolymer ionization detector.
Date:
February 26, 2007
Creator:
LePort, F.; Pocar, A.; Bartoszek, L.; DeVoe, R.; Fierlinger, P.; Flatt, B. et al.
Object Type:
Report
System:
The UNT Digital Library
Controls of Fluid Chemistry on Fracture Growth
During this two year project (the original proposal requested 3 years funding) we developed and tested a new design for a mini-bending jig for the hydrothermal atomic force microscope (HAFM) and a modified design for the HAFM itself. These new capabilities now permit study of the connection between stress and mineral dissolution and growth, as well as sub-critical crack growth (SCG). We demonstrated the successful design by imaging SCG of glass in situ, in real time in the HAFM, as a function of changing solution pH. We generated a movie of the SCG process. We successfully accomplished our project objectives through year 2.
Date:
February 26, 2007
Creator:
Bruton, C.; Knauss, K.; Viani, B. & Bonner, B.
Object Type:
Report
System:
The UNT Digital Library
04-ERD-052-Final Report
Generating the sequence of the human genome represents a colossal achievement for science and mankind. The technical use for the human genome project information holds great promise to cure disease, prevent bioterror threats, as well as to learn about human origins. Yet converting the sequence data into biological meaningful information has not been immediately obvious, and we are still in the preliminary stages of understanding how the genome is organized, what are the functional building blocks and how do these sequences mediate complex biological processes. The overarching goal of this program was to develop novel methods and high throughput strategies for determining the functions of ''anonymous'' human genes that are evolutionarily deeply conserved in other vertebrates. We coupled analytical tool development and computational predictions regarding gene function with novel high throughput experimental strategies and tested biological predictions in the laboratory. The tools required for comparative genomic data-mining are fundamentally the same whether they are applied to scientific studies of related microbes or the search for functions of novel human genes. For this reason the tools, conceptual framework and the coupled informatics-experimental biology paradigm we developed in this LDRD has many potential scientific applications relevant to LLNL multidisciplinary research in bio-defense, …
Date:
February 26, 2007
Creator:
Loots, G. G.; Ovcharenko, I.; Collette, N.; Babu, P.; Chang, J.; Stubbs, L. et al.
Object Type:
Report
System:
The UNT Digital Library
Final Report: Ionization chemistry of high temperature molecular fluids
With the advent of coupled chemical/hydrodynamic reactive flow models for high explosives, understanding detonation chemistry is of increasing importance to DNT. The accuracy of first principles detonation codes, such as CHEETAH, are dependent on an accurate representation of the species present under detonation conditions. Ionic species and non-molecular phases are not currently included coupled chemistry/hydrodynamic simulations. This LDRD will determine the prevalence of such species during high explosive detonations, by carrying out experimental and computational investigation of common detonation products under extreme conditions. We are studying the phase diagram of detonation products such as H{sub 2}O, or NH{sub 3} and mixtures under conditions of extreme pressure (P > 1 GPa) and temperature (T > 1000K). Under these conditions, the neutral molecular form of matter transforms to a phase dominated by ions. The phase boundaries of such a region are unknown.
Date:
February 26, 2007
Creator:
Fried, L E
Object Type:
Report
System:
The UNT Digital Library
Evaluated Decay Data for {Sup 246}CM.
The Nuclear Data and Measurement Series document results of studies in the field of microscopic nuclear data. The primary objective is the dissemination of information in the comprehensive form required for nuclear technology applications. This Series is devoted to: (a) measured microscopic nuclear parameters, (b) experimental techniques and facilities employed in measurements, (c) the analysis, correlation and interpretation of nuclear data, and (d) the compilation and evaluation of nuclear data. Contributions to this Series are reviewed to assure technical competence and, unless otherwise stated, the contents can be formally referenced. This Series does not supplant formal journal publication, but it does provide the more extensive information required for technological applications (e.g., tabulated numerical data) in a timely manner.
Date:
February 26, 2007
Creator:
Kondev, F. G.
Object Type:
Report
System:
The UNT Digital Library
SINGLE-CELL LEVEL INVESTIGATION OF CYTOSKELETAL/CELLULAR RESPONSE TO EXTERNAL STIMULI
A detailed understanding of the molecular mechanisms by which chemical signals control cell behavior is needed if the complex biological processes of embryogenesis, development, health and disease are to be completely understood. Yet, if we are to fully understand the molecular mechanisms controlling cell behavior, measurements at the single cell level are needed to supplement information gained from population level studies. One of the major challenges to accomplishing studies at the single cell level has been a lack of physical tools to complement the powerful molecular biological assays which have provided much of what we currently know about cell behavior. The goal of this exploratory project is the development of an experimental platform that facilitates integrated observation, tracking and analysis of the responses of many individual cells to controlled environmental factors (e.g. extracellular signals). Toward this goal, we developed chemically-patterned microarrays of both adherent and suspension mammalian cell types. A novel chemical patterning methodology, based on photocatalytic lithography, was developed to construct biomolecule and cell arrays that facilitate analysis of biological function. Our patterning techniques rely on inexpensive stamp materials and visible light, and do not necessitate mass transport or specified substrates. Patterned silicon and glass substrates are modified such …
Date:
February 26, 2007
Creator:
Hiddessen, A L
Object Type:
Report
System:
The UNT Digital Library
Final Report for Nuclear Lattice Simulations with Chiral Effective Field Theory
The nuclear lattice program at North Carolina State University addresses the nuclear many-body problem by applying non-perturbative lattice methods directly to hadrons. In this approach nucleons are treated as point particles on a lattice with a lattice spacing between 1 and 4 fm. The low energy interactions of the nucleons are governed by effective field theory and the unknown operator coefficients are determined by fitting to few-body scattering data. By using hadronic degrees of freedom and concentrating on low-energy physics, it is possible to probe larger volumes, lower temperatures, and far greater numbers of nucleons than in lattice QCD. In some cases the sign/complex phase problem can even be completely eliminated.
Date:
February 26, 2007
Creator:
Lee, Dean
Object Type:
Report
System:
The UNT Digital Library
Local Structure and Vibrational Properties of α'-Pu Martensitein Ga-Stabilized δ-Pu
Extended x-ray absorption fine structure spectroscopy (EXAFS) is used to investigate the local atomic environment and vibrational properties of plutonium and gallium atoms in the {alpha}{prime} and {delta} phases of a mixed phase Pu-Ga alloy. EXAFS results measured at low temperature compare the structure of the mixed phase sample with a single-phase {delta}-Pu sample. EXAFS spectral components attributed to both {alpha}{prime}-Pu and {delta}-Pu were observed in the mixed phase sample. Ga K-edge EXAFS spectra indicate local atomic environments similar to the Pu LIII-edge EXAFS results, which suggests that Ga is substitutional for Pu atoms in both the monoclinic {alpha}{prime}-Pu and the fcc {delta}-Pu structures. In {delta}-Pu, we measure a Ga-Pu bond length contraction of 0.11 Angstroms with respect to the Pu-Pu bond length. The corresponding bond-length contraction around Ga in {alpha}{prime}-Pu is only 0.03 Angstroms. Results from temperature-dependent Pu LIII-edge EXAFS measurements are fit to a correlated Debye model, and a large difference in the Pu-Pu bond Debye temperature is observed for the {alpha}{prime} and {delta} phases: {theta}{sub cD}({alpha}{prime})=159{+-}13 K versus {theta}{sub cD}({delta})=120{+-}3 K. The corresponding analysis for the Ga K EXAFS determines a Ga-Pu bond Debye temperature of {theta}{sub cD}({delta})=188{+-}12 K in the {delta}-Pu phase. These results are related …
Date:
February 26, 2003
Creator:
Nelson, E. J.; Blobaum, K. J. M.; Wall, M. A.; Allen, P. G.; Schwartz, A. J. & Booth, C. H.
Object Type:
Article
System:
The UNT Digital Library
Energy Harvesting for Structural Health Monitoring Sensor Networks
This report has been developed based on information exchanges at a 2.5-day workshop on energy harvesting for embedded structural health monitoring (SHM) sensing systems that was held June 28-30, 2005, at Los Alamos National Laboratory. The workshop was hosted by the LANL/UCSD Engineering Institute (EI). This Institute is an education- and research-focused collaboration between Los Alamos National Laboratory (LANL) and the University of California, San Diego (UCSD), Jacobs School of Engineering. A Statistical Pattern Recognition paradigm for SHM is first presented and the concept of energy harvesting for embedded sensing systems is addressed with respect to the data acquisition portion of this paradigm. Next, various existing and emerging sensing modalities used for SHM and their respective power requirements are summarized, followed by a discussion of SHM sensor network paradigms, power requirements for these networks and power optimization strategies. Various approaches to energy harvesting and energy storage are discussed and limitations associated with the current technology are addressed. This discussion also addresses current energy harvesting applications and system integration issues. The report concludes by defining some future research directions and possible technology demonstrations that are aimed at transitioning the concept of energy harvesting for embedded SHM sensing systems from laboratory research …
Date:
February 26, 2007
Creator:
G. Park, C. R. Farrar, M. D. Todd, W. Hodgkiss, T. Rosing
Object Type:
Report
System:
The UNT Digital Library
The Wylie News (Wylie, Tex.), Vol. 55, No. 40, Ed. 1 Wednesday, February 26, 2003
Weekly newspaper from Wylie, Texas that includes local, state and national news along with advertising.
Date:
February 26, 2003
Creator:
Engbrock, Chad B.
Object Type:
Newspaper
System:
The Portal to Texas History
Rains County Leader (Emory, Tex.), Vol. 114, No. 37, Ed. 1 Tuesday, February 26, 2002
Weekly newspaper from Emory, Texas that includes local, state, and national news along with advertising.
Date:
February 26, 2002
Creator:
Hill, Earl Clyde, Jr.
Object Type:
Newspaper
System:
The Portal to Texas History
Seminole Sentinel (Seminole, Tex.), Vol. 97, No. 40, Ed. 1 Sunday, February 26, 2006
Semiweekly newspaper from Seminole, Texas that includes local, state, and national news along with extensive advertising.
Date:
February 26, 2006
Creator:
Wright, Dustin
Object Type:
Newspaper
System:
The Portal to Texas History
Timpson & Tenaha News (Timpson, Tex.), Vol. 19, No. 8, Ed. 1 Thursday, February 26, 2004
Weekly newspaper from Timpson, Texas that includes local, state, and national news along with advertising.
Date:
February 26, 2004
Creator:
Alexander, Nancy
Object Type:
Newspaper
System:
The Portal to Texas History
Polk County Enterprise (Livingston, Tex.), Vol. 124, No. 17, Ed. 1 Sunday, February 26, 2006
Semi-weekly newspaper from Livingston, Texas that includes local, state and national news along with advertising.
Date:
February 26, 2006
Creator:
White, Barbara
Object Type:
Newspaper
System:
The Portal to Texas History