Collection
Office of Scientific & Technical Information Technical Reports
1,253
Congressional Research Service Reports
773
Defense Base Closure and Realignment Commission
331
Government Accountability Office Reports
277
Texas Laws and Resolutions Archive
64
Texas Attorney General Opinions
38
Texas Register
19
Texas State Publications
9
Federal Register
3
End of Term Publications
2
5 More
Country
States
Decade
Month
Day
Language
2,774 Matching Results
Results open in a new window/tab.
Appendix D-12A Building 332C Waste Accumulation Area
This appendix is designed to provide information specific to the Building 332C Waste Accumulation Area (B-332C WAA), a waste storage area. This appendix is not designed to be used as a sole source of information. All general information that is not specific to the B-332C WAA is included in the Contingency Plan for Waste Accumulation Areas, dated July 2004, and should be referenced. The B-332C WAA is located in the southwest quadrant of the LLNL Main Site in Building 332, Room 1330. Hazardous and mixed wastes may be stored at the B-332C WAA for 90 days or less, until transferred to the appropriate Radioactive and Hazardous Waste Management (RHWM) facility or other permitted treatment, storage or disposal facility (TSDF). Radioactive waste may also be stored at the WAA. The design storage capacity of this WAA is 2,200 gallons.
Date:
January 21, 2005
Creator:
Chase, Dawn
Object Type:
Report
System:
The UNT Digital Library
Quarkonium at Finite Temperature.
The author discusses quarkonium spectral functions at finite temperature reconstructed using the Maximum Entropy Method. The author shows in particular that the J/{psi} survives in the deconfined phase up to 1.5T{sub c}.
Date:
July 21, 2003
Creator:
Petreczky, P.
Object Type:
Article
System:
The UNT Digital Library
Engineering Annual Summary 2003
None
Date:
July 21, 2004
Creator:
Patterson, S R
Object Type:
Report
System:
The UNT Digital Library
Polymer pendant crown thioethers for removal of mercury from acidic wastes: synthesis, characterization and application
Removal of mercury ions from industrial waste streams is a difficult and expensive problem requiring an efficient and selective extractant that is resistant to corrosive conditions. We have now developed an acid-resistant thiacrown polymer that has potential utility as a selective and cost-effective Hg{sup 2+} extractant. Copolymerization of a novel C-substituted thiacrown, N,N-(4-vinylbenzylmethyl)-2-aminomethyl-1,4,8,11,14-pentathiacycloheptadecane, with DVB (80% divinylbenzene) using a radical initiator generated a highly cross-linked polymer containing pendant thiacrowns. Mercury extraction capabilities of the polymer were tested in acidic media (pH range: 1.5 to 6.2) and the extraction of Hg{sup 2+} was determined to be 95% at a mixing time of 30 minutes. The thiacrown polymer was also determined to be selective for Hg{sup 2+}, even in the presence of high concentrations of competing ions such as Pb{sup 2+}, Cd{sup 2+}, Al{sup 3}, and Fe{sup 3+}. The bound Hg{sup 2+} ions can then be stripped from the polymer, allowing the polymer to be reused without significant loss of loading capacity. The binding of Hg{sup 2+} to the polymer has been examined by X-ray photoemission spectroscopy. The thiacrown appears unaffected by incorporation into the polymer and the Hg{sup 2+} appears to be bound to the polymer complex in a similar manner …
Date:
July 21, 2000
Creator:
Reynolds, J G; Baumann, T F; Nelson, A J & Fox, G A
Object Type:
Article
System:
The UNT Digital Library
Analysis of the November 1999 Dead Sea Calibration Shots
In November 1999 three chemical explosions were conducted in the Dead Sea for the purposes of calibrating the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). These shots were organized and conducted by the Geophysical Institute of Israel (GII). Large chemical explosions are the most valuable form of ground truth as the location, depth and origin time are very well known. We focus on the two largest shots (M{sub w} {ge} 3.6) and performed several types of analysis of the regional recordings and travel times of these shots. These data provide valuable new information about the region and offer an opportunity to test monitoring strategies. A crustal and uppermost mantle velocity model was inferred from the travel times of the regional phases: Pn, Pg and Sg. This effort utilized a grid search method to find suitable models of the structure. Results indicate that the crust is relatively thin (32 km) with lower than average crustal velocities (mean V{sub P} = 6.1-6.2 km/s). We located each shot treating the other shot as a calibration explosion. Locations were computed using both station static corrections and kriged correction surfaces. Results show that the locations with static corrections can be better or …
Date:
July 21, 2000
Creator:
Rodgers, A J; Myers, S; Mayeda, K & Walter, W
Object Type:
Article
System:
The UNT Digital Library
Chemically Transformable Configurations of Mercaptohexadecanoic Acid Self-Assembled Monolayers Adsorbed on Au(111)
Carboxyl terminated Self-Assembled Monolayers (SAMs) are commonly used in a variety of applications, with the assumption that the molecules form well ordered monolayers. In this work, NEXAFS verifies well ordered monolayers can be formed using acetic acid in the solvent. Disordered monolayers with unbound molecules present in the result using only ethanol. A stark reorientation occurs upon deprotonation of the endgroup by rinsing in a KOH solution. This reorientation of the endgroup is reversible with tilted over, hydrogen bound carboxyl groups while carboxylate-ion endgroups are upright. C1s photoemission shows that SAMs formed and rinsed with acetic acid in ethanol, the endgroups are protonated, while without, a large fraction of the molecules on the surface are carboxylate terminated.
Date:
October 21, 2003
Creator:
van Buuren, T; Bostedt, C; Nelson, A J; Terminello, L J; Vance, A L; Fadley, C S et al.
Object Type:
Article
System:
The UNT Digital Library
Virtual Proving Ground for Assessing Reliability and Uncertainty
The process for accurately estimating product reliability early in the development process can be a difficult and costly task. Traditional methods like Reliability Prediction Models and Life Testing Strategies yield beneficial results when relative information is known about the product that is to be analyzed. When there is minimal information (e.g., prior failure rates, etc.), such as in new concept design, these above reliability methods have limitations. For these cases computer simulation technology has proven to yield valuable results. This paper will demonstrate analysis procedures for assessing the margin and reliability of product design in the early product development stage. This analysis process is composed of requirements definition, a mathematical model, model validation, parameter diagram, design of experiment (DOE), response surface, and optimization. The analysis process shows its impacts, in the following areas: reducing the product development cycle, reducing cost, increasing confidence, and estimating product reliability. This is particularly important early in the concept development process.
Date:
July 21, 2004
Creator:
Hsieh, H & Sam, D
Object Type:
Article
System:
The UNT Digital Library
Hydrodynamic Instability of Ionization Fronts in HII Regions
The authors investigate hydrodynamic instability of accelerating ionization fronts with two dimensional hydrodynamic simulations. When recombination in the ionized region is turned off, Rayleigh-Taylor instability is effective. Perturbation grows up with classical Rayleigh-Taylor growth rate. In the case with recombination, the local difference of absorption profile works to smooth the surface. The perturbation does not grow and the amplitude follows a damped oscillations with time.
Date:
August 21, 2003
Creator:
Mizuta, A.; Kane, J.; Ryutov, D.; Remington, B.; Takabe, H. & Pound, M.
Object Type:
Article
System:
The UNT Digital Library
Distortion Correction for the Many Beam Fabry Perot Velocimeter
Graphical curves and text tables are presented that map out time and space distortions for data obtained from film records of the Many Beam Fabry Perot Velocimeter. Effective distortion corrections extracted from these mappings can be applied to upcoming velocimetry experiments, but only with limited success over periods of a year or more into the future. A method of using three fiducials to provide fresh time and space distortion data on each film record is presented as a more reliable procedure to correct distortions to an acceptable level of accuracy.
Date:
March 21, 2001
Creator:
Avara, G.; Collins, L. & Rivera, A.
Object Type:
Report
System:
The UNT Digital Library
Fluid Effects on Shear Waves in FInely Layered Porous Media
Although there are five effective shear moduli for any layered VTI medium, one and only one effective shear modulus for the layered system contains all the dependence of pore fluids on the elastic or poroelastic constants that can be observed in vertically polarized shear waves. Pore fluids can increase the magnitude the shear energy stored by this modulus by a term that ranges from the smallest to the largest shear moduli of the VTI system. But, since there are five shear moduli in play, the increase in shear energy overall is reduced by a factor of about 5 in general. We can therefore give definite bounds on the maximum increase of shear modulus, being about 20% of the permitted range, when gas is fully replaced by liquid. An attendant increase of density (depending on porosity and fluid density) by approximately 5 to 10% partially offsets the effect of this shear modulus increase. Thus, an increase of shear wave speed on the order of 5 to 10% is shown to be possible when circumstances are favorable - i.e., when the shear modulus fluctuations are large (resulting in strong anisotropy), and the medium behaves in an undrained fashion due to fluid trapping. …
Date:
May 21, 2004
Creator:
Berger, E. L.
Object Type:
Article
System:
The UNT Digital Library
Permanent Magnet Designs With Large Variations in Field Strength.
The use of permanent magnets has been investigated as an option for electron cooling ring for the proposed luminosity upgrade of RHIC. Several methods have been developed that allow a large variation in field strength. These design concepts were verified with computer simulations using finite element codes. It will be shown that the field uniformity is maintained while the field strength is mechanically adjusted.
Date:
January 21, 2004
Creator:
Gupta, R.
Object Type:
Article
System:
The UNT Digital Library
HIF VNL Progress Report to DOE, April 22, 2005
We have made progress in learning to use the code Hydra to do detailed modeling of targets for Accelerator Driven High Energy Density Physics. Hydra is a state-of-the-art 3D, radiative transfer hydrodynamics modeling code developed at LLNL. In particular, we have carried out two-dimensional simulations of a 23 MeV, 1 mm radius Neon beam striking a 48 micron thick Aluminum foil at 10% solid density, and observed the heating of the foil by the beam. The Bragg peak was chosen to fall near the center of the foil, and as expected, rarefaction waves propagated symmetrically inward (at a speed of order the sound speed), as the heated material flowed outward and cooled. Foams allow relatively high temperatures to be attained over longer timescales, and the foils behaved, at least qualitatively, as predicted by previous analysis. Design of a number of configurations, ion species, and material compositions will be carried out using this code. Further, calculations by our collaborators at Tech-X corporation have compared results from the SRIM code (a code for understanding detailed energy deposition and scattering of ions in a cold solid) with cold dEdX curves published by Northcliffe and Schilling in 1970. The latter publication was used for …
Date:
April 21, 2005
Creator:
Barnard, J
Object Type:
Report
System:
The UNT Digital Library
Coarse-Grained Molecular Dynamics: Dissipation Due to Internal Modes
We describe progress on the issue of pathological elastic wave reflection in atomistic and multiscale simulation. First we briefly review Coarse-Grained Molecular Dynamics (CGMD). Originally CGMD was formulated as a Hamiltonian system in which energy is conserved. This formulation is useful for many applications, but recently CGMD has been extended to include generalized Langevin forces. Here we describe how Langevin dynamics arise naturally in CGMD, and we examine the implication for elastic wave scattering.
Date:
December 21, 2001
Creator:
Rudd, R E
Object Type:
Article
System:
The UNT Digital Library
NIF-0096141-OA Prop Simulations of NEL PBRS Measurements
Portable Back Reflection Sensor, PBRS, (NEL only) and Quad Back Reflection Sensor, QBRS, time delay reflectometer traces are among the most useful diagnostics of NIF laser status available. NEL PBRS measurements show several signals reaching the detector for each shot. The time delay between signals suggests that the largest of these is due to energy at the spatial filter pinhole planes leaking into adjacent pinholes and traveling back upstream to the PBRS. Prop simulations agree with current PBRS measurements to within 50%. This suggests that pinhole leakage is the dominant source of energy at the PBRS. However, the simulations predict that the energy leakage is proportional to beam output energy, while the PBRS measurements increase more slowly (''saturate''). Further refinement of the model or the measurement may be necessary to resolve this discrepancy.
Date:
February 21, 2003
Creator:
Widmayer, C. & Manes, K.
Object Type:
Report
System:
The UNT Digital Library
DIAMOND AMPLIFIER FOR PHOTOCATHODES.
We report a new approach to the generation of high-current, high-brightness electron beams. Primary electrons are produced by a photocathode (or other means) and are accelerated to a few thousand electron-volts, then strike a specially prepared diamond window. The large Secondary Electron Yield (SEY) provides a multiplication of the number of electrons by about two orders of magnitude. The secondary electrons drift through the diamond under an electric field and emerge into the accelerating proper of the ''gun'' through a Negative Electron Affinity surface of the diamond. The advantages of the new approach include the following: (1) Reduction of the number of primary electrons by the large SEY, i.e. a very low laser power in a photocathode producing the primaries. (2) Low thermal emittance due to the NEA surface and the rapid thermalization of the electrons. (3) Protection of the cathode from possible contamination from the gun, allowing the use of large quantum efficiency but sensitive cathodes. (4) Protection of the gun from possible contamination by the cathode, allowing the use of superconducting gun cavities. (5) Production of high average currents, up to ampere class. (6) Encapsulated design, making the ''load-lock'' systems unnecessary. This paper presents the criteria that need …
Date:
June 21, 2004
Creator:
Rao, T.; Ben-Zvi, Ilan; Burrill, A.; Chang, X.; Hulbert, S.; Johnson, P. D. et al.
Object Type:
Article
System:
The UNT Digital Library
Printed wiring board fabrication and lead elimination via single-bath electrodeposition
Printed wiring board (PWB) fabrication, an operation performed both at LLNL and throughout the electronics industry, generates considerable quantities of hazardous waste, notably lead-bearing materials used for soldering, tinning, and finish coating the circuits of the board. Hot-air solder leveling (HASL), the most common method of finishing is one of the main sources of hazardous lead-bearing wastes in traditional PWB manufacturing. The development of a safer finishing method will lead to employee health and environmental benefits. In addition, there is a production advantage to eliminating HASL, for it provides a fairly uneven surface that is problematic for mounting very small components. In this project, we developed ''single-bath electroplating'' as a potential HASL replacement technology for many applications. Single-bath electroplating involves alternating deposition of one or the other metal component of a bimetal bath, through control of plating potential and mass transport. It employs a nickel layer as both etch resist and finish coat and has the potential for lowering environmental and human-health risks associated with PWB manufacture--while at the same time reconfiguring the process for greater efficiency and profitability.
Date:
February 21, 2001
Creator:
Meltzer, M P & Steffani, C P
Object Type:
Report
System:
The UNT Digital Library
Simulations of Beam Emittance Growth from the Collective Relaxation of Space-Charge Nonuniformities
None
Date:
June 21, 2004
Creator:
Lund, S M; Grote, D P & Davidson, R C
Object Type:
Article
System:
The UNT Digital Library
Superconducting Detector System for High-Resolution Energy-Dispersive Soft X-Ray Spectroscopy
Synchrotron-based soft x-ray spectroscopy is often limited by detector performance. Grating spectrometers have the resolution, but lack the efficiency for the analysis of dilute samples. Semiconducting Si(Li) or Ge detectors are efficient, but often lack the resolution to separate weak signals from strong nearby lines in multi-element samples. Superconducting tunnel junctions (STJs) operated at temperatures below 1 K can be used as high-resolution high-efficiency x-ray detectors. They combine high energy resolution around 10 eV FWHM with the broad band efficiency of energy-dispersive detectors. We have designed a two-stage adiabatic demagnetization refrigerator (ADR) to operate STJ detectors in x-ray fluorescence measurements at beam line 4 of the ALS. We demonstrate the capabilities of such a detector system for fluorescence analysis of dilute metal sites in proteins and inorganic model compounds.
Date:
February 21, 2001
Creator:
Friedrich, S; Niedermayr, T; Drury, O; Funk, T; Frank, M; Labov, S E et al.
Object Type:
Report
System:
The UNT Digital Library
Delineation of Fast Flow Paths in Porous Media Using Noble Gas Tracers
Isotopically enriched xenon isotopes are ideal for tracking the flow of relatively large volumes of groundwater. Dissolved noble gas tracers behave conservatively in the saturated zone, pose no health risk to drinking water supplies, and can be used with a large dynamic range. Different Xe isotopes can be used simultaneously at multiple recharge sources in a single experiment. Results from a tracer experiment at a California water district suggests that a small fraction of tracer moved from the recharge ponds through the thick, unconfined, coarse-grained alluvial aquifer to high capacity production wells at a horizontal velocity of 6 m/day. In contrast, mean water residence times indicate that the average rate of transport is 0.5 to 1 m/day.
Date:
March 21, 2002
Creator:
Hudson, G. B. & Moran, J. E.
Object Type:
Report
System:
The UNT Digital Library
Physics and Advanced Technologies LDRD Final Report:Adaptive Optics Imaging and Spectroscopy of the Solar System
This focus of this project was the investigation of the planets Uranus and Neptune and Saturn's moon Titan using adaptive optics imaging and spectroscopy at the 10-meter W.M. Keck Telescopes. These bodies share a common type of atmosphere, one that is rich in methane and has a hydrocarbon haze layer produced by methane photolysis. Neptune and Uranus have atmospheric features which change on short timescales; we have investigated their altitude, composition, and connection to events occurring deeper in the planets' tropospheres. Titan has a solid surface located under its atmosphere, the composition of which is still quite uncertain. With spectra that sample the vertical structure of the atmosphere and narrowband observations that selectively probe Titan's surface we have determined the surface reflectivity of Titan at near-infrared wavelengths.
Date:
January 21, 2004
Creator:
Gibbard, S; Max, C; Macintosh, B & Grossman, A
Object Type:
Report
System:
The UNT Digital Library
Are Published Minimum Vapor Phase Spark Ignition Energy Data Valid?
The use of sprayed flammable fluids as solvents in dissolution and cleaning processes demand detailed understanding of ignition and fire hazards associated with these applications. When it is not feasible to inert the atmosphere in which the spraying process takes place, then elimination of all possible ignition sources must be done. If operators are involved in the process, the potential for human static build-up and ultimate discharge is finite, and it is nearly impossible to eliminate. The specific application discussed in this paper involved the use of heated Dimethyl Sulfoxide (DMSO) to dissolve high explosives (HE). Search for properties of DMSO yielded data on flammability limits and flash point, but there was no published information pertaining to the minimum energy for electrical arc ignition. Due to the sensitivity of this procedure, The Hazards Control Department of Lawrence Livermore National Laboratory (LLNL) was tasked to determine the minimum ignition energy of DMSO aerosol and vapor an experimental investigation was thus initiated. Because there were no electrical sources in spray chamber, Human Electro-Static Discharge (HESD) was the only potential ignition source. Consequently, the electrostatic generators required for this investigation were designed to produce electrostatic arcs with the defined voltage and current pulse …
Date:
November 21, 2001
Creator:
Staggs, K J; Alvares, N J & Greenwood, D W
Object Type:
Article
System:
The UNT Digital Library
Instructions for Installation of the Whole-Building Diagnostician Software Release 2.10-162
The Whole Building Diagnostician (WBD) is modular diagnostic software that detects and diagnoses common problems associated with heating, ventilating, and air conditioning systems and equipment. This instruction document describes how to install the WBD and the Microsoft Data Access Object components, how to view the results in the demonstration database, and the new features of the Whole Building energy module (WBE).
Date:
August 21, 2003
Creator:
Carlon, Teresa A. & Bauman, Nathan N.
Object Type:
Report
System:
The UNT Digital Library
IR Extinction Coefficient Measurements of CH and CD GDP Shells
None
Date:
March 21, 2003
Creator:
Cook, R C & Nikroo, A
Object Type:
Report
System:
The UNT Digital Library
Optical Extinction of Sapphire Shock Loaded to 250-260 GPa
Sapphire, a common optical window material used in shock-compression studies, displays significant shock-induced optical emission and extinction. It is desirable to quantify such non-ideal window behavior to enhance the usefulness of sapphire in optical studies of opaque shock-compressed samples, such as metals. At the highest stresses we can achieve with a two-stage gas gun it is technically very difficult to study the optical properties of sapphire without the aid of some opaque backing material, hence one is invariably compelled to deconvolve the optical effects of the opaque surface and the sapphire. In an effort to optimize this deconvolution process, we have constructed sapphire/thin-film/sapphire samples using two basic types of thin films: one optimized to emit copious optical radiation (the hot-film sample), the other designed to yield minimal emission (the cold-film sample). This sample geometry makes it easy to maintain the same steady shock-stress in the sapphire window (255 GPa in our case) while varying the window/film interface temperature. A six-channel time-resolved optical pyrometer is used to measure the emission from the sample assemblies. Two different sapphire crystal orientations were evaluated. We also comment on finite thermal conductivity effects of the thin-film geometry on the interpretation of our data.
Date:
August 21, 2001
Creator:
Hare, D. E.; Webb, D. J.; Lee, S. H. & Holmes, N.
Object Type:
Article
System:
The UNT Digital Library