Materials Evaluation Test Series (METS) 04, 05, and 06 (open access)

Materials Evaluation Test Series (METS) 04, 05, and 06

The purpose of this work is to examine the environmental, safety, health and operational aspects of detonating a confined explosive test apparatus that has been designed to maximize the dynamics of impact on beryllium metal components for Contained Firing Facility (CFF) applications. A combination of experimental collection and evaluation methods were designed and implemented to provide an evaluation of immediately postdetonation by-products reflecting a potential worst-case scenario beryllium aerosolization explosive event. The collective Material Evaluation Test Series (METS) 04 - 06 provided explosive devices designed to scale for the dedicated METS firing tank that would provide a post-detonation internal environment comparable to the CFF. The experimental results provided appropriate information to develop operational parameters to be considered for conducting full-scale beryllium-containing experimental tests with similar designs within CFF and B801A. These operational procedures include the inclusion of chelating agents in pre-shot CFF cardboard containers with a minimum of 600 gallons content, an extended time period post-test before purging the CFF chamber, and an adaptation of approaches toward applications of the scrubber and HEPA systems during the post-shot sequence for an integrated environmental, safety, and health approach. In addition, re-entry and film retrieval procedures will be adapted, in line with abatement …
Date: March 23, 2006
Creator: Zalk, D.; Ingram, C.; Simmons, L.; Arganbright, R.; Lyle, J. & Wong, K.
Object Type: Report
System: The UNT Digital Library
Stark Tuning of Donor Electron Spins of Silicon (open access)

Stark Tuning of Donor Electron Spins of Silicon

We report Stark shift measurements for {sup 121}Sb donor electron spins in silicon using pulsed electron spin resonance. Interdigitated metal gates on top of a Sb-implanted {sup 28}Si epi-layer are used to apply electric fields. Two Stark effects are resolved: a decrease of the hyperfine coupling between electron and nuclear spins of the donor and a decrease in electron Zeeman g-factor. The hyperfine term prevails at X-band magnetic fields of 0.35T, while the g-factor term is expected to dominate at higher magnetic fields. A significant linear Stark effect is also resolved presumably arising from strain.
Date: March 23, 2006
Creator: Bradbury, Forrest R.; Tyryshkin, Alexei M.; Sabouret, Guillaume; Bokor, Jeff; Schenkel, Thomas & Lyon, Stephen A.
Object Type: Article
System: The UNT Digital Library
Vlt and Acs Observations of RDCS J1252.9-2927: Dynamical Structure and Galaxy Populations in a Massive Cluster at Z=1.237* (open access)

Vlt and Acs Observations of RDCS J1252.9-2927: Dynamical Structure and Galaxy Populations in a Massive Cluster at Z=1.237*

We present results from an extensive spectroscopic survey, carried out with FORS on the ESO Very Large Telescope, and from an extensive multi-wavelength imaging data set from the Advanced Camera for Surveys and ground based facilities of the cluster of galaxies RDCS J1252.9-2927. We have spectroscopically confirmed 38 cluster members in the redshift range 1.22 < z < 1.25. The distribution in velocity of these spectroscopic members yields a cluster median redshift of z = 1.237 and a rest-frame velocity dispersion of 747{sub -84}{sup +74} km s{sup -1}. Star-forming members are observed to mainly populate the outskirts of the cluster while passive galaxies dominate the central cluster region. Using the 38 confirmed redshifts, we were able to resolve, for the first time at z > 1, kinematic structure. The velocity distribution, which is not Gaussian at the 95% confidence level, is consistent with two groups that are also responsible for the projected elongation of the cluster in the East-West direction. The groups are composed of 26 and 12 galaxies and have velocity dispersions of 486{sub -85}{sup +47} km s{sup -1} and 426{sub -105}{sup +57} km s{sup -1}, respectively. The elongation is also seen in the intracluster gas (from X-ray observations) …
Date: March 23, 2007
Creator: Demarco, R.; Rosati, P.; Lidman, C.; Girardi, M.; Nonino, M.; Rettura, A. et al.
Object Type: Article
System: The UNT Digital Library
Influence of argon and oxygen on charge-state-resolved ion energydistributions of filtered aluminum arcs (open access)

Influence of argon and oxygen on charge-state-resolved ion energydistributions of filtered aluminum arcs

The charge-state-resolved ion energy distributions (IEDs) in filtered aluminum vacuum arc plasmas were measured and analyzed at different oxygen and argon pressures in the range 0.5 8.0 mTorr. A significant reduction of the ion energy was detected as the pressure was increased, most pronounced in an argon environment and for the higher charge states. The corresponding average charge state decreased from 1.87 to 1.0 with increasing pressure. The IEDs of all metal ions in oxygen were fitted with shifted Maxwellian distributions. The results show that it is possible to obtain a plasma composition with a narrow charge-state distribution as well as a narrow IED. These data may enable tailoring thin-film properties through selecting growth conditions that are characterized by predefined charge state and energy distributions.
Date: March 23, 2006
Creator: Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil & Schneider, Jochen M.
Object Type: Article
System: The UNT Digital Library
Hydrologic Resources Management Program and Underground Test Area Project FY2005 Progress Report (open access)

Hydrologic Resources Management Program and Underground Test Area Project FY2005 Progress Report

This report describes FY 2005 technical studies conducted by the Chemical Biology and Nuclear Science Division (CBND) at Lawrence Livermore National Laboratory (LLNL) in support of the Hydrologic Resources Management Program (HRMP) and the Underground Test Area Project (UGTA). These programs are administered by the U.S. Department of Energy, National Nuclear Security Administration, Nevada Site Office (NNSA/NSO) through the Defense Programs and Environmental Restoration Divisions, respectively. HRMP-sponsored work is directed toward the responsible management of the natural resources at the Nevada Test Site (NTS), enabling its continued use as a staging area for strategic operations in support of national security. UGTA-funded work emphasizes the development of an integrated set of groundwater flow and contaminant transport models to predict the extent of radionuclide migration from underground nuclear testing areas at the NTS. The report is organized on a topical basis and contains five chapters that highlight technical work products produced by CBND. However, it is important to recognize that most of this work involves collaborative partnerships with the other HRMP and UGTA contract organizations. These groups include the Energy and Environment Directorate at LLNL (LLNL-E&E), Los Alamos National Laboratory (LANL), the Desert Research Institute (DRI), the U.S. Geological Survey (USGS), Stoller-Navarro …
Date: March 23, 2007
Creator: Eaton, G. F.; Genetti, V.; Hu, Q.; Hudson, G. B.; Kersting, A. B.; Lindvall, R. E. et al.
Object Type: Report
System: The UNT Digital Library
Nano-subgrain Strengthening in Ball-milled Iron (open access)

Nano-subgrain Strengthening in Ball-milled Iron

The strength and deformation behavior of ball-milled, iron-base materials containing nano-scale subgrains have been evaluated. As reported by several authors, nanosubgrains form during the early stages of ball milling as a result of severe plastic deformation inherent in the ball milling process. The strength for these nano-scale subgrains are compared with the strength of larger-scale subgrains in iron and iron-base alloys produced by traditional mechanical working. The data covers over 2 orders of magnitude in subgrain size (from 30 nm to 6 {micro}m) and shows a continuous pattern of behavior. For all materials studied, the strength varied as {lambda}{sup -1}, where {lambda} is the subgrain size. Strengthening from subgrains was found to breakdown at a much smaller subgrain size than strengthening from grains. In addition, the ball-milled materials showed significant strengthening contributions from nano-scale oxide particles. Shear bands are developed during testing of ball-milled materials containing ultra-fine subgrains. A model for shear band development in nano-scale subgrains during deformation has also been developed. The model predicts a strain state of uniaxial compression in the shear band with a strain of -1.24. Subgrains are shown to offer the opportunity for high strength and good work hardening with the absence of yield …
Date: March 23, 2006
Creator: Lesuer, D R; Syn, C K & Sherby, O D
Object Type: Article
System: The UNT Digital Library
Formation, Stability, and Mobility of One-Dimensional Lipid Bilayer on High Curvature Substrates (open access)

Formation, Stability, and Mobility of One-Dimensional Lipid Bilayer on High Curvature Substrates

Curved lipid membranes are ubiquitous in living systems and play an important role in many biological processes. To understand how curvature and lipid composition affect membrane formation and fluidity we have assembled and studied mixed 1,2-Dioleoyl-sn-Glycero-3-Phosphocholine (DOPC) and 1,2-Dioleoyl-sn-Glycero-3-Phosphoethanolamine (DOPE) supported lipid bilayers on amorphous silicon nanowires with controlled diameters ranging from 20 nm to 200 nm. Addition of cone-shaped DOPE molecules to cylindrical DOPC molecules promotes vesicle fusion and bilayer formation on smaller diameter nanowires. Our experiments demonstrate that nanowire-supported bilayers are mobile, exhibit fast recovery after photobleaching, and have low concentration of defects. Lipid diffusion coefficients in these high-curvature tubular membranes are comparable to the values reported for flat supported bilayers and increase with decreasing nanowire diameter.
Date: March 23, 2007
Creator: Huang, J.; Martinez, J.; Artyukhin, A.; Sirbuly, D.; Wang, Y.; Ju, J. W. et al.
Object Type: Article
System: The UNT Digital Library
Effect of solution saturation state and temperature on diopside dissolution (open access)

Effect of solution saturation state and temperature on diopside dissolution

Steady-state dissolution rates of diopside are measured as a function of solution saturation state using a titanium flow-through reactor at pH 7.5 and temperature ranging from 125 to 175 C. Diopside dissolved stoichiometrically under all experimental conditions and rates were not dependent on sample history. At each temperature, rates continuously decreased by two orders of magnitude as equilibrium was approached and did not exhibit a dissolution plateau of constant rates at high degrees of undersaturation. The variation of diopside dissolution rates with solution saturation can be described equally well with a ion exchange model based on transition state theory or pit nucleation model based on crystal growth/dissolution theory from 125 to 175 C. At 175 C, both models over predict dissolution rates by two orders of magnitude indicating that a secondary phase precipitated in the experiments. The ion exchange model assumes the formation of a Si-rich, Mg-deficient precursor complex. Lack of dependence of rates on steady-state aqueous calcium concentration supports the formation of such a complex, which is formed by exchange of protons for magnesium ions at the surface.
Date: March 23, 2007
Creator: Dixit, S & Carroll, S A
Object Type: Article
System: The UNT Digital Library
Texas Attorney General Opinion: GA-0533 (open access)

Texas Attorney General Opinion: GA-0533

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification: Counties’ alternatives for disposing of seized gambling contraband (RQ-0536-GA)
Date: March 23, 2007
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: GA-0168 (open access)

Texas Attorney General Opinion: GA-0168

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification: Implementing section 1602.267 of the Occupations Code, which establishes a one-year shampoo apprentice permit (RQ-0118-GA)
Date: March 23, 2004
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Statutory Royalty Rates for Digital Performance of Sound Recordings: Decision of the Copyright Royalty Board (open access)

Statutory Royalty Rates for Digital Performance of Sound Recordings: Decision of the Copyright Royalty Board

None
Date: March 23, 2009
Creator: unknown
Object Type: Report
System: The UNT Digital Library
State Securities Class Action Suits: Merrill Lynch, Pierce, Fenner & Smith, Inc. v. Dabit (open access)

State Securities Class Action Suits: Merrill Lynch, Pierce, Fenner & Smith, Inc. v. Dabit

None
Date: March 23, 2006
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Hong Kong’s Ongoing Transition: Implications of Chinese Sovereignty in 2001. March 2001 (open access)

Hong Kong’s Ongoing Transition: Implications of Chinese Sovereignty in 2001. March 2001

This report focuses on the situation in Hong Kong as it continues its political and social transformation after the July 1997 reversion to Chinese sovereignty.
Date: March 23, 2001
Creator: Dumbaugh, Kerry
Object Type: Report
System: The UNT Digital Library
Types of Committee Hearings (open access)

Types of Committee Hearings

None
Date: March 23, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Wild and Scenic Rivers Act and Federal Water Rights (open access)

The Wild and Scenic Rivers Act and Federal Water Rights

This report discusses federal authority over water, and federal "reserved" and non-reserved water rights.
Date: March 23, 2006
Creator: Baldwin, Pamela
Object Type: Report
System: The UNT Digital Library
The Low-Income Home Energy Assistance Program (LIHEAP): Program and Funding (open access)

The Low-Income Home Energy Assistance Program (LIHEAP): Program and Funding

None
Date: March 23, 2006
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Kyrgyzstan: Recent Developments and U.S. Interests (open access)

Kyrgyzstan: Recent Developments and U.S. Interests

None
Date: March 23, 2005
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Appropriations for FY2004: Foreign Operations, Export Financing, and Related Programs (open access)

Appropriations for FY2004: Foreign Operations, Export Financing, and Related Programs

This report provides appropriations of Foreign Operations, Export Financing, and Related Programs for FY2004.
Date: March 23, 2004
Creator: Nowels, Larry
Object Type: Report
System: The UNT Digital Library
Vietnam’s Labor Rights Regime: An Assessment (open access)

Vietnam’s Labor Rights Regime: An Assessment

None
Date: March 23, 2001
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Nonlinear optical absorption in laser modified regions of fused silica substrates (open access)

Nonlinear optical absorption in laser modified regions of fused silica substrates

The presence of strong nonlinear absorption has been observed in laser modified fused silica. Intensity-dependent transmission measurements using 355-nm, 532-nm and 1,064-nm laser pulses were performed in pristine polished regions in fused silica substrates and in locations that were exposed to dielectric breakdown. The experimental results suggest that multi-photon absorption is considerably stronger in the modified regions compared to pristine sites and is strongly dependent on the excitation wavelength.
Date: March 23, 2004
Creator: Walser, A D; Demos, S; Etienne, M & Dorsinville, R
Object Type: Article
System: The UNT Digital Library
The Option of Freezing Non-defense Discretionary Spending to Reduce the Budget Deficit (open access)

The Option of Freezing Non-defense Discretionary Spending to Reduce the Budget Deficit

None
Date: March 23, 2005
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Campaign Finance Reform: Regulating Political Communications on the Internet (open access)

Campaign Finance Reform: Regulating Political Communications on the Internet

This report describes regulating political communications on the Internet related to Campaign Finance Reform.
Date: March 23, 2006
Creator: Whitaker, L. Paige
Object Type: Report
System: The UNT Digital Library
Community Development Block Grant Funds in Disaster Relief and Recovery (open access)

Community Development Block Grant Funds in Disaster Relief and Recovery

This report provides information about the Community Development Block Grant Funds in Disaster Relief and Recovery. Over the years, congress has appropriated supplemental CDBG funds supported recovery efforts in New York city.
Date: March 23, 2006
Creator: Boyd, Eugene
Object Type: Report
System: The UNT Digital Library
Thermal Decomposition of Trinitrotoluene (TNT) with a New One-Dimensional Time to Explosion (ODTX) Apparatus (open access)

Thermal Decomposition of Trinitrotoluene (TNT) with a New One-Dimensional Time to Explosion (ODTX) Apparatus

The thermal explosion of trinitrotoluene (TNT) is used as a basis for evaluating the performance of a new One-Dimensional-Time-to-Explosion (ODTX) apparatus. The ODTX experiment involves holding a 12.7 mm-diameter spherical explosive sample under confinement (150 MPa) at a constant elevated temperature until the confining pressure is exceeded by the evolution of gases during chemical decomposition. The resulting time to explosion as a function of temperature provides valuable decomposition kinetic information. A comparative analysis of the measurements obtained from the new unit and an older system is presented. Discussion on selected performance aspects of the new unit will also be presented. The thermal explosion of TNT is highly dependent on the material. Analysis of the time to explosion is complicated by historical and experimental factors such as material variability, sample preparation, temperature measurement and system errors. Many of these factors will be addressed. Finally, a kinetic model using a coupled thermal and heat transport code (chemical TOPAZ) was used to match the experimental data.
Date: March 23, 2001
Creator: Tran, T. D.; Simpson, R. L.; Maienschein, J. & Tarver, Craig M.
Object Type: Article
System: The UNT Digital Library