Texas Attorney General Opinion: LO98-043 (open access)

Texas Attorney General Opinion: LO98-043

Letter opinion 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, Dan Morales, regarding a legal question submitted for clarification; Interpretation of Senate Bill 667, establishing program to assist individuals with hearing or speech impairment to purchase specialized telecommunications device for telephone access (ID# 39619)
Date: June 2, 1998
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: LO98-044 (open access)

Texas Attorney General Opinion: LO98-044

Letter opinion 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, Dan Morales, regarding a legal question submitted for clarification; Status of work performed by county attorney while he simultaneously held the office of municipal judge (RQ-1053)
Date: June 2, 1998
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Conceptual design report for immobilized high-level waste interim storage facility (Phase 1) (open access)

Conceptual design report for immobilized high-level waste interim storage facility (Phase 1)

The Hanford Site Canister Storage Building (CSB Bldg. 212H) will be utilized to interim store Phase 1 HLW products. Project W-464, Immobilized High-Level Waste Interim Storage, will procure an onsite transportation system and retrofit the CSB to accommodate the Phase 1 HLW products. The Conceptual Design Report establishes the Project W-464 technical and cost basis.
Date: June 2, 1998
Creator: Burgard, K. C.
Object Type: Report
System: The UNT Digital Library
SURFACE ACOUSTIC WAVE MERCURY VAPOR SENSOR (open access)

SURFACE ACOUSTIC WAVE MERCURY VAPOR SENSOR

Sensor Research and Development Corporation (SRD) has been contracted to develop and deliver a prototype instrument capable of the in situ detection and measurement of low levels of gaseous mercury for use in thermal treatment process control applications and continuous emissions monitoring. The goal is to develop a fast, simple, inexpensive and reliable in situ sensor instrument for detecting and monitoring vaporized mercury that should be able to react to extremely low (< 200 ppb) levels of mercury vapor, should be site deployable and provide continuous data on either cumulative mercury exposure or instantaneous concentration. To date, a delivery system for gaseous mercury has been designed and constructed, sensor responses have been measured and analyzed for a wide range of sensing film thicknesses and operating temperatures, a microheater and temperature control circuitry and software have been designed and implemented, and a contract modification, which has received initial approval from DOE, to include measurement of total mercury (both in elemental and reacted forms) has been drafted.
Date: June 2, 1998
Creator: Caron, Joshua
Object Type: Report
System: The UNT Digital Library
Production and characterization of x-ray speckle at sector 8 of the Advanced Photon Source. (open access)

Production and characterization of x-ray speckle at sector 8 of the Advanced Photon Source.

The authors have implemented in the undulator first-optics enclosure of the Massachusetts Institute of Technology-McGill University-IBM Corporation Collaborative Access Team Sector at the Advanced Photon Source an x-ray beamline and a spectrometer optimized for performing small-angle, wide-bandpass, coherent-x-ray-scattering experiments. They describe the novel features of this set-up. The performance of the beamline and the spectrometer has been characterized by measuring static x-ray speckle patterns from isotropically-discarded aerogels. Statistical analysis of the special patterns has been performed from which they extract the speckle widths and contrast versus wave-vector transfer and sample thickness. The measured speckle widths and contrast are compared to direct numerical evaluations of the intensity correlation function. The calculated widths are in poor agreement with the measurements but the calculated contrast agrees well with the measured contrast.
Date: June 2, 1998
Creator: Lurio, L. B.; Malik, A.; Mochrie, S. G.; Sandy, A. R.; Stephenson, G. B. & Sutton, M.
Object Type: Article
System: The UNT Digital Library
Diagnosing hot electron production by short pulse, high intensity lasers using photonuclear reactions (open access)

Diagnosing hot electron production by short pulse, high intensity lasers using photonuclear reactions

Solid targets irradiated with 10{sup 19} W/cm{sup 2} or greater of 1 {mu}m light in picosecond pulses are found to be radioactive. The strongest activities observed are the result of photonuclear reactions in which an energetic photon excites the nucleus sufficiently to produce particle emission leaving a radioactive daughter. The photoreaction cross sections are known for a wide range of nuclei and provide a quantitative measure of the photon flux produced in the target. Both the delayed daughter activities and measurements of the prompt particles emitted in the reaction can be used as diagnostics. Examples of these techniques applied in diagnosing experiments at the Nova laser facility adapted to generate petawatt pulses using chirped pulse amplification will be presented. These results will be compared with bremsstrahlung photon spectra calculated using electron spectra measured in a magnetic spectrograph. {copyright} {ital 1999 American Institute of Physics.}
Date: June 2, 1998
Creator: Phillips, T. W.; Cable, M. D.; Cowan, T. E.; Hatchett, S. P.; Henry, E. A.; Key, M. H. et al.
Object Type: Article
System: The UNT Digital Library
High-energy 4{omega} probe laser for laser-plasma experiments at nova (open access)

High-energy 4{omega} probe laser for laser-plasma experiments at nova

For the characterization of inertial confinement fusion plasmas we implemented a high-energy 4{omega} probe laser at the Nova laser facility. A total energy of > 50 Joules at 4{omega}, a focal spot size of order 100 {micro}m, and a pointing accuracy of 100 {micro}m was demonstrated for target shots. This laser provides intensities of up to 3 x 10{sup 14}W cm{sup -2} and therefore fulfills high-power requirements for laser-plasma interaction experiments. The 4{omega} probe laser is now routinely used for Thomson scattering. Successful experiments were performed in gas-filled hohlraums at electron densities of n{sub e} > 2 X 10{sup 21}cm{sup -3} which represents the highest density plasma so far being diagnosed with Thomson scattering.
Date: June 2, 1998
Creator: Glenzer, S. H., LLNL
Object Type: Article
System: The UNT Digital Library
Achromatically filtered diamond photoconductive detectors for high power soft x-ray flux measurements (open access)

Achromatically filtered diamond photoconductive detectors for high power soft x-ray flux measurements

A 1 mm square diamond photoconductive detector (PCD) has been installed on the LLNL Nova laser system, for use as a broad band soft x-ray power diagnostic. The PCD is installed behind an array of pinholes, which cast multiple, overlapping images of the source onto the diamond. This allows reduction of the x-ray intensity, to avoid saturation problems, while avoiding the spectral dependency of thin film filters. The diode current is read out on a 5 GHz bandwidth scope. The system is calibrated by comparison to an absolutely calibrated array of filtered vacuum x-ray photodiodes (XRD` s) (``dante``). The time response of the PCD and its bias electronics have been characterized using the 5th harmonic (210 nm) of a short pulse (< 1 ps) Ti:sapphire laser. The data show a fast rise, limited by the 5 GHz scope bandwidth, and a slower fall off, characterized by an RC time of order 200 ps.
Date: June 2, 1998
Creator: Turner, R. E.
Object Type: Article
System: The UNT Digital Library
Fiber optic based optical coherence tomography (OCT) for dental applications (open access)

Fiber optic based optical coherence tomography (OCT) for dental applications

We have developed a hand-held fiber optic based optical coherence tomography (OCT) system for scanning of the oral cavity We have produced, using this scanning device, in viva cross-sectional images of hard and soft dental tissues in human volunteers Clinically relevant anatomical structures, including the gingival margin, periodontal sulcus, and dento-enamel junction, were visible in all the images The dento-enamel junction and the alveolar bone were identifiable in approximately two thirds of the images These images represent, to our knowledge, the first in viva OCT images of human dental tissue.
Date: June 2, 1998
Creator: Everett, M. J., LLNL
Object Type: Article
System: The UNT Digital Library
Fudge: a high-bandwidth fusion diagnostic of the NIF (open access)

Fudge: a high-bandwidth fusion diagnostic of the NIF

Diagnostics for the National Ignition Facility (NIF)/Inertial Confinement Fusion (ICF) program must include good characterization of the fusion source. Ideally, diagnostics would measure the spatially-resolved history of the fusion reaction rate and temperature. Existing diagnostics can satisfy this goal only partially. One class of new techniques that could play a major role in high-yield diagnostics is measurements based on fusion {gamma} rays. The Fusion Diagnostic Gamma Experiment (FUDGE) can be used to perform energy-resolved measurements of (D,T) fusion reaction rates This diagnostic is based on the 16 7-MeV {gamma} rays that are produced by (D,T) fusion. The {gamma} rays are free of spectral dispersion and can be detected with a high bandwidth Cherenkov detector. A simple magnetic monochromator selects signals from the 16 7-MeV {gamma} rays and reduces background signals from non-fusion {gamma} rays.
Date: June 2, 1998
Creator: Moran, M. J., LLNL
Object Type: Article
System: The UNT Digital Library
Measurements of near forward scattered laser light in a large ICF plasma (open access)

Measurements of near forward scattered laser light in a large ICF plasma

We describe an instrument which measures the angular spread and spectrum of near forward scattered laser light from a probe beam in a long scalelength laser-plasma. The instrument consists of a combination of time integrating and time resolving detectors which measure the scattered light amplitude over four orders of magnitude for a range of angles. These measurements allow us to study the beam spray resulting from various laser and plasma conditions and determine the density fluctuations associated with this beam spray.
Date: June 2, 1998
Creator: Moody, J. D.
Object Type: Article
System: The UNT Digital Library
Filtered x-ray diode diagnostics fielded on the Z-accelerator for source power measurements (open access)

Filtered x-ray diode diagnostics fielded on the Z-accelerator for source power measurements

Filtered x-ray diode, (XRD), detectors are used as primary radiation flux diagnostics on Sandia`s Z-accelerator, which generates nominally a 200 TW, 2 MJ, x-ray pulse. Given such flux levels and XRD sensitivities the detectors are being fielded 23 meters from the source. The standard diagnostic setup and sensitivities are discussed. Vitreous carbon photocathodes are being used to reduce the effect of hydrocarbon contamination present in the Z-machine vacuum system. Nevertheless pre- and post-calibration data taken indicate spectrally dependent changes in the sensitivity of these detectors by up to factors up to 2 or 3.
Date: June 2, 1998
Creator: Chandler, G.A.; Deeney, C. & Cuneo, M.
Object Type: Article
System: The UNT Digital Library
X-ray absorption spectroscopy studies of electrochemically deposited thin oxide films. (open access)

X-ray absorption spectroscopy studies of electrochemically deposited thin oxide films.

We have utilized ''in situ'' X-ray Absorption Fine Structure Spectroscopy to investigate the structure and composition of thin oxide films of nickel and iron that have been prepared by electrodeposition on a graphite substrate from aqueous solutions. The films are generally disordered. Structural information has been obtained from the analysis of the data. We also present initial findings on the local structure of heavy metal ions, e.g. Sr and Ce, incorporated into the electrodeposited nickel oxide films. Our results are of importance in a number of technological applications, among them, batteries, fuel cells, electrochromic and ferroelectric materials, corrosion protection, as well as environmental speciation and remediation.
Date: June 2, 1998
Creator: Balasubramanian, M.
Object Type: Article
System: The UNT Digital Library
Analytical performance of direct-hydrogen-fueled polymer electrolyte fuel cell (PEFC) systems for transportation applications. (open access)

Analytical performance of direct-hydrogen-fueled polymer electrolyte fuel cell (PEFC) systems for transportation applications.

The performance of a stand-alone polymer electrolyte fuel cell (PEFC) system directly fueled by hydrogen has been evaluated for transportation vehicles. The study was carried out using a systems analysis code and a vehicle analysis code. The systems code includes models for the various PEFC components and is applicable for steady-state and transient situations. At the design point the system efficiency is above 50% for a 50-kW system. The efficiency improves under partial load and approaches 60% at 40% load, as the fuel cell operating point moves to lower current densities on the V-I polarization curve. At much lower loads, the system efficiency drops because of the deterioration in the performance of the compressor, expander, and eventually the fuel cell. The system performance suffers at lower temperatures, as the V-I characteristic curve for the fuel cell shifts downward because of the increased ohmic losses. The results of the transient analysis indicate that the hydrogen-fueled PEFC system can start rather rapidly, within seconds from ambient conditions. However, the warm-up time constant to reach the design operating temperatures is about 180 s. It is important during this period for the coolant to bypass the system radiator until the coolant temperature approaches the …
Date: June 2, 1998
Creator: Doss, E. D.
Object Type: Article
System: The UNT Digital Library
Recovery characteristics of high damping elastomers used in seismic isolation bearings. (open access)

Recovery characteristics of high damping elastomers used in seismic isolation bearings.

The protection of nuclear and civil structures from the destructive effects of earthquakes has been the focus of intense research and development throughout the world. Seismic isolation is an effective means for reducing and even eliminating the devastating consequences of earthquakes on people, equipment and structures. Engineers have developed many devices for implementing the seismic isolation strategy and the most effective and economical ones have been identified through the test of time. One of these devices is the laminated elastomeric isolation bearing. The behavior of high damping elastomer bearings during several recent earthquakes has shown that they are a viable device for mitigating the effects of earthquakes. In this paper, results are presented from recent tests on two different elastomers. The first is a highly filled, high modulus, high damping elastomer and the second is a highly-filled, low modulus, high damping elastomer. The stiffness recovery characteristics of the high modulus elastomer subjected to beyond design basis strains and the results of seven years of aging on the low modulus elastomer are presented.
Date: June 2, 1998
Creator: Kulak, R. F.
Object Type: Article
System: The UNT Digital Library
Magnetic and Charge Fluctuations in High-T(Sub c) Superconductors (open access)

Magnetic and Charge Fluctuations in High-T(Sub c) Superconductors

Neutron scattering has been used to study the spin fluctuations in the YBaCuO and BiSrCaCuO materials. Evidence is found for both incommensurate fluctuations and a commensurate resonance excitation. Measurements on the lattice dynamics for YBaCuO show incommensurate structure that appears to stem from charge fluctuations that are associated with the spin fluctuations.
Date: June 2, 1998
Creator: Chakoumakos, B.C.; Dogan, F. & Mook, H.A.
Object Type: Article
System: The UNT Digital Library
Femtosecond laser materials processing (open access)

Femtosecond laser materials processing

Femtosecond lasers enable materials processing of most any material with extremely high precision and negligible shock or thermal loading to the surrounding area Applications ranging from drilling teeth to cutting explosives to making high-aspect ratio cuts in metals with no heat-affected zone are made possible by this technology For material removal at reasonable rates, we developed a fully computer-controlled 15-Watt average power, 100-fs laser machining system.
Date: June 2, 1998
Creator: Stuart, B. C., LLNL
Object Type: Article
System: The UNT Digital Library
A FIELD-SCALE MODELING STUDY AND CHARACTERIZING HYDRAULIC PROPERTIES FOR WATER, AIR AND HEAT FLOW IN THE UNSATURATED ZONE OF YUCCA MOUNTAIN, NEVADA (open access)

A FIELD-SCALE MODELING STUDY AND CHARACTERIZING HYDRAULIC PROPERTIES FOR WATER, AIR AND HEAT FLOW IN THE UNSATURATED ZONE OF YUCCA MOUNTAIN, NEVADA

None
Date: June 2, 1998
Creator: Y.S. WU, S. FINSTERLE, AND G.S. BODVARSSON
Object Type: Report
System: The UNT Digital Library
Nitrogen addition affects leaf nutrition and photosynthesis in sugar maple in a nutrient poor northern Vermont forest (open access)

Nitrogen addition affects leaf nutrition and photosynthesis in sugar maple in a nutrient poor northern Vermont forest

None
Date: June 2, 1998
Creator: Ellsworth, David S.
Object Type: Article
System: The UNT Digital Library