Experimental Results in Support of Simulating Progressive Crush in Carbon-Fiber Textile Composites (open access)

Experimental Results in Support of Simulating Progressive Crush in Carbon-Fiber Textile Composites

This report summarizes the findings of an experimental program conducted to support the modeling of the crush behavior of triaxial braid carbon fiber composites. The matrix material as well as braided panels and tubes were characterized in order to determine material properties, to assess failure modes, and to provide a test bed for new analytical and numerical tools developed specifically for braided composites. The matrix material selected by the ACC was an epoxy vinyl ester (Ashland Hetron 922). Tensile tests were used to compare two formulations-one used by the ACC and one recommended by the resin supplier. The latter was a faster reacting system and gelled in one-third the time of the ACC formulation. Both formulations had an average elongation at failure that was only half of the resin supplier's reported value. Only one specimen of each type came close to the reported elongation value and it was shown that failure invariably initiated at both surface and internal defects. Overall, the tensile properties of the two formulations were nearly identical, but those of the ACC system were more consistent. The properties of the ACC matrix formulation were measured in tension, shear, and compression and the average properties obtained in these …
Date: April 2, 2001
Creator: DeTeresa, S J; Allison, L M; Cunningham, B J; Freeman, DC; Saculla, M D; Sanchez, R J et al.
System: The UNT Digital Library
ISCR FY2005 Annual Report (open access)

ISCR FY2005 Annual Report

Large-scale scientific computation and all of the disciplines that support and help validate it have been placed at the focus of Lawrence Livermore National Laboratory (LLNL) by the Advanced Simulation and Computing (ASC) program of the National Nuclear Security Administration (NNSA) and the Scientific Discovery through Advanced Computing (SciDAC) initiative of the Office of Science of the Department of Energy (DOE). The maturation of simulation as a fundamental tool of scientific and engineering research is underscored in the President's Information Technology Advisory Committee (PITAC) June 2005 finding that ''computational science has become critical to scientific leadership, economic competitiveness, and national security''. LLNL operates several of the world's most powerful computers--including today's single most powerful--and has undertaken some of the largest and most compute-intensive simulations ever performed, most notably the molecular dynamics simulation that sustained more than 100 Teraflop/s and won the 2005 Gordon Bell Prize. Ultrascale simulation has been identified as one of the highest priorities in DOE's facilities planning for the next two decades. However, computers at architectural extremes are notoriously difficult to use in an efficient manner. Furthermore, each successful terascale simulation only points out the need for much better ways of interacting with the resulting avalanche of …
Date: February 2, 2006
Creator: Keyes, D E & McGraw, J R
System: The UNT Digital Library
Chemical Technology Division annual technical report, 2001. (open access)

Chemical Technology Division annual technical report, 2001.

The Chemical Technology Division (CMT) is one of eight engineering research divisions within Argonne National Laboratory, one of the U.S. government's oldest and largest research laboratories. The University of Chicago oversees the laboratory on behalf of the U.S. Department of Energy (DOE). Argonne's mission is to conduct basic scientific research, to operate national scientific facilities, to enhance the nation's energy resources, and to develop better ways to manage environmental problems. Argonne has the further responsibility of strengthening the nation's technology base by developing innovative technology and transferring it to industry. CMT is a diverse early-stage engineering organization, specializing in the treatment of spent nuclear fuel, development of advanced electrochemical power sources, and management of both high- and low-level nuclear wastes. Although this work is often indistinguishable from basic research, our efforts are directed toward the practical devices and processes that are covered by Argonne's mission. Additionally, the Division operates the Analytical Chemistry Laboratory and Environment, Safety, and Health Analytical Chemistry services, which provide a broad range of analytical services to Argonne and other organizations. The Division is multidisciplinary. Its people have formal training as ceramists; physicists; material scientists; electrical, mechanical, chemical, and nuclear engineers; and chemists. They have experience working …
Date: July 2, 2002
Creator: Lewis, D.; Gay, E. C.; Miller, J. C. & Boparai, A. S.
System: The UNT Digital Library
Vadose Zone Transport Field Study: FY 2002 Status Report (open access)

Vadose Zone Transport Field Study: FY 2002 Status Report

This work reported here is part of the U. S. Department of Energy’s Science and Technology Initiative to develop improved conceptual models of flow and transport in the vadose zone, particularly for the Hanford Site, Washington. The National Academy of Sciences has identified significant knowledge gaps in conceptual model development as one reason for discovery of subsurface contamination in unexpected places. Inadequate conceptualizations limits, not only the understanding of long-term fate and transport, but also the selection and design of remediation technologies. Current conceptual models are limited partly because they do not account for the random heterogeneity that occurs under the extremes of very nonlinear flow behavior typical of the Hanford vadose zone. A major improvement in conceptual modeling of the Hanford vadose zone includes a better understanding and description of soil anisotropy, a property that appears to control much of the subsurface flow and transport in layered sediments at the Hanford Site.
Date: January 2, 2003
Creator: Ward, Anderson L.; Gee, Glendon W.; Zhang, Z. F. & Keller, Jason M.
System: The UNT Digital Library
Hydrodynamic phenomena of gas-filled chamber due to target implosion in fusion reactors. (open access)

Hydrodynamic phenomena of gas-filled chamber due to target implosion in fusion reactors.

Use of an intermediate gas in the reaction chamber of an inertial fusion power reactor is under consideration to decrease the thermal shock to the walls resulting from target implosions. A model was developed and implemented in HEIGHTS package to simulate hydrodynamic and radiation shock waves in the chamber and used to determine the effect of xenon gas at various densities ranging from mtorr up to tens of torr. Numerical calculations for the dense-gas case indicated that two pressure peaks result from the shock wave interacting with the chamber wall, and radiation energy accumulates directly in front of the hydrodynamic shock wave. The shock wave should reach a maximum pressure peak when the chamber gas has a density between the two extremes analyzed. In general, calculated results with our model compared favorably with previously published data.
Date: July 2, 2003
Creator: Sizyuk, V. & Hassanein, A.
System: The UNT Digital Library
Laboratory Directed Research and Development FY2002 Annual Report (open access)

Laboratory Directed Research and Development FY2002 Annual Report

None
Date: May 2, 2003
Creator: Al-Ayat, R
System: The UNT Digital Library
Proceedings of the 3rd US-Japan Workshop on Plasma Polarization Spectroscopy (open access)

Proceedings of the 3rd US-Japan Workshop on Plasma Polarization Spectroscopy

The third US-Japan Workshop on Plasma Polarization Spectroscopy was held at the Lawrence Livermore National Laboratory in Livermore, California, on June 18-21, 2001. The talks presented at this workshop are summarized in these proceedings. The papers cover both experimental investigation and applications of plasma polarization spectroscopy as well as the theoretical foundation and formalisms to understand and describe the polarization phenomena. The papers give an overview of the history of plasma polarization spectroscopy, derive the formal aspects of polarization spectroscopy, including the effects of electric and magnetic fields, discuss spectra perturbed by intense microwave fields, charge exchange, and dielectronic recombination, and present calculations of various collisional excitation and ionization cross sections and the modeling of plasma polarization spectroscopy phenomena. Experimental results are given from the WT-3 tokamak, the MST reverse field pinch, the Large Helical Device, the GAMMA 10 mirror machine, the Nevada Terrawatt Facility, the Livermore EBIT-II electron beam ion trap, and beam-foil spectroscopy. In addition, results were presented from studies of several laser-produced plasma experiments and new instrumental techniques were demonstrated.
Date: January 2, 2002
Creator: Beiersdorfer, P & Flyimoto, T
System: The UNT Digital Library
Scanning Hall Probe Microscopy of Magnetic Vortices inVery Underdoped yttrium-barium-copper-oxide (open access)

Scanning Hall Probe Microscopy of Magnetic Vortices inVery Underdoped yttrium-barium-copper-oxide

Since their discovery by Bednorz and Mueller (1986), high-temperature cuprate superconductors have been the subject of intense experimental research and theoretical work. Despite this large-scale effort, agreement on the mechanism of high-T{sub c} has not been reached. Many theories make their strongest predictions for underdoped superconductors with very low superfluid density n{sub s}/m*. For this dissertation I implemented a scanning Hall probe microscope and used it to study magnetic vortices in newly available single crystals of very underdoped YBa{sub 2}Cu{sub 3}O{sub 6+x} (Liang et al. 1998, 2002). These studies have disproved a promising theory of spin-charge separation, measured the apparent vortex size (an upper bound on the penetration depth {lambda}{sub ab}), and revealed an intriguing phenomenon of ''split'' vortices. Scanning Hall probe microscopy is a non-invasive and direct method for magnetic field imaging. It is one of the few techniques capable of submicron spatial resolution coupled with sub-{Phi}{sub 0} (flux quantum) sensitivity, and it operates over a wide temperature range. Chapter 2 introduces the variable temperature scanning microscope and discusses the scanning Hall probe set-up and scanner characterizations. Chapter 3 details my fabrication of submicron GaAs/AlGaAs Hall probes and discusses noise studies for a range of probe sizes, which suggest …
Date: December 2, 2005
Creator: Guikema, Janice Wynn & /SLAC, SSRL
System: The UNT Digital Library
Congressional Investigations: Subpoenas and Contempt Power (open access)

Congressional Investigations: Subpoenas and Contempt Power

When conducting investigations of the executive branch, congressional committees and Members of Congress generally receive the information required for legislative needs. If agencies fail to cooperate or the President invokes executive privilege, Congress can turn to a number of legislative powers that are likely to compel compliance. The two techniques described in this report are the issuance of subpoenas and the holding of executive officials in contempt. These techniques usually lead to an accommodation that meets the needs of both branches. Litigation is used at times, but federal judges generally encourage congressional and executive parties to settle their differences out of court. The specific examples in this report explain how information disputes arise and how they are resolved.
Date: April 2, 2003
Creator: Fisher, Louis
System: The UNT Digital Library
Plant Wide Assessment for Johns Manville Waterville Ohio Plant 1 (open access)

Plant Wide Assessment for Johns Manville Waterville Ohio Plant 1

The report describes activites carried out at the palnt to identify energy savings in various energy user systems. The results list areas of energy savings potential and metods of energy savings.
Date: July 2, 2006
Creator: Kissock, Kelly & Thekdi, Arvind
System: The UNT Digital Library
Privacy: An Overview of Federal Statutes Governing Wiretapping and Electronic Eavesdropping (open access)

Privacy: An Overview of Federal Statutes Governing Wiretapping and Electronic Eavesdropping

This report provides an overview of federal law governing wiretapping and electronic eavesdropping. It also appends citations to state law in the area and contains a bibliography of legal commentary as well as the text of the Electronic Communications Privacy Act (ECPA) and the Foreign Intelligence Surveillance Act (FISA). This report also includes a brief summary of the recently expired Protect America Act, P.L. 110-55 and of the Foreign Intelligence Surveillance Act of 1978 Amendments Act of 2008, P.L. 110-261 (H.R. 6304).
Date: September 2, 2008
Creator: Stevens, Gina & Doyle, Charles
System: The UNT Digital Library
Data Packages for the Hanford Immobilized Low Activity Tank Waste Performance Assessment 2001 Version [SEC 1 THRU 5] (open access)

Data Packages for the Hanford Immobilized Low Activity Tank Waste Performance Assessment 2001 Version [SEC 1 THRU 5]

Data package supporting the 2001 Immobilized Low-Activity Waste Performance Analysis. Geology, hydrology, geochemistry, facility, waste form, and dosimetry data based on recent investigation are provided. Verification and benchmarking packages for selected software codes are provided.
Date: March 2, 2000
Creator: MANN, F.M.
System: The UNT Digital Library