Geobotanical Remote Sensing for Geothermal Exploration (open access)

Geobotanical Remote Sensing for Geothermal Exploration

This paper presents a plan for increasing the mapped resource base for geothermal exploration in the Western US. We plan to image large areas in the western US with recently developed high resolution hyperspectral geobotanical remote sensing tools. The proposed imaging systems have the ability to map visible faults, surface effluents, historical signatures, and discover subtle hidden faults and hidden thermal systems. Large regions can be imaged at reasonable costs. The technique of geobotanical remote sensing for geothermal signatures is based on recent successes in mapping faults and effluents the Long Valley Caldera and Mammoth Mountain in California.
Date: May 22, 2001
Creator: Pickles, W. L.; Kasameyer, P. W.; Martini, B. A.; Potts, D. C. & Silver, E. A.
Object Type: Article
System: The UNT Digital Library
Recent X-Ray Laser Experiments on the COMET Facility (open access)

Recent X-Ray Laser Experiments on the COMET Facility

The development of the transient collisional excitation x-ray laser scheme using tabletop laser systems with multiple pulse capability has progressed rapidly in the last three years. The high small-signal gain and strong x-ray output have been demonstrated for laser drive energies of typically less than 10 J. We report recent x-ray laser experiments on the Lawrence Livermore National Laboratory (LLNL) Compact Multipulse Terawatt (COMET) tabletop facility using this technique. In particular, the saturated output from the Ni-like Pd ion 4d - 4p x-ray laser at 146.8 {angstrom} has been well characterized and has potential towards a useable x-ray source in a number of applications. One important application of a short wavelength x-ray laser beam with picosecond pulse duration is the study of a high density laser-produced plasma. We report the implementation of a Mach-Zehnder type interferometer using diffraction grating optics as beam splitters designed for the Ni-like Pd laser and show results from probing a 600 ps heated plasma. In addition, gas puff targets are investigated as an x-ray laser gain medium and we report results of strong lasing on the n = 3 - 3 transitions of Ne-like Ar.
Date: September 22, 2001
Creator: Dunn, J.; Smith, R. F.; Nilsen, J.; Hunter, J. R.; Barbee, T. W.; Shlyaptsev, V. N. et al.
Object Type: Article
System: The UNT Digital Library
Applications of Computational Fluid Dynamics Simulations in Urban Environments and Experiments Designed to Aid the Development and Evaluation of these Models (open access)

Applications of Computational Fluid Dynamics Simulations in Urban Environments and Experiments Designed to Aid the Development and Evaluation of these Models

Progress in development of CFD models has shown their great potential for prediction of air flow, heat dissipation, and dispersion of air pollutants in the urban environment. Work at Lawrence Livermore National Laboratory has progressed using the finite element code FEM3 which has been ''massively parallelized'' to produce flow fields and pollutant dispersion in a grid encompassing many city blocks and with high resolution. While it may be argued that urban CFD models are not yet economical for emergency response applications, there are many applications in assessments and air quality management where CFD models are unrivaled in the level of detail that they provide. We have conducted field experiments to define the flow field and air tracer dispersion around buildings as a means of critiquing and evaluating the CFD models. The first experiment, the ''B170 study'', was a study of flow field, turbulence, and tracer dispersion in separation zones around a complex, single building. The second was the URBAN 2000 experiment in downtown Salt Lake City where flow fields and tracers were studied in nested resolution from the single building scale up to larger scales of 25 city blocks, and out to 6 km. For the future an URBAN 2003 …
Date: August 22, 2001
Creator: Shinn, J & Gouveia, F J
Object Type: Article
System: The UNT Digital Library
Time-Reversal Acoustics and Maximum-Entropy Imaging (open access)

Time-Reversal Acoustics and Maximum-Entropy Imaging

Target location is a common problem in acoustical imaging using either passive or active data inversion. Time-reversal methods in acoustics have the important characteristic that they provide a means of determining the eigenfunctions and eigenvalues of the scattering operator for either of these problems. Each eigenfunction may often be approximately associated with an individual scatterer. The resulting decoupling of the scattered field from a collection of targets is a very useful aid to localizing the targets, and suggests a number of imaging and localization algorithms. Two of these are linear subspace methods and maximum-entropy imaging.
Date: August 22, 2001
Creator: Berryman, James G.
Object Type: Article
System: The UNT Digital Library
3(omega) Damage: Growth Mitigation (open access)

3(omega) Damage: Growth Mitigation

The design of high power UV laser systems is limited to a large extent by the laser-initiated damage performance of transmissive fused silica optical components. The 3{omega} (i.e., the third harmonic of the primary laser frequency) damage growth mitigation LDRD effort focused on understanding and reducing the rapid growth of laser-initiated surface damage on fused silica optics. Laser-initiated damage can be discussed in terms of two key issues: damage initiated at some type of precursor and rapid damage growth of the damage due to subsequent laser pulses. The objective of the LDRD effort has been the elucidation of laser-induced damage processes in order to quantify and potentially reduce the risk of damage to fused silica surfaces. The emphasis of the first two years of this effort was the characterization and reduction of damage initiation. In spite of significant reductions in the density of damage sites on polished surfaces, statistically some amount of damage initiation should always be expected. The early effort therefore emphasized the development of testing techniques that quantified the statistical nature of damage initiation on optical surfaces. This work led to the development of an optics lifetime modeling strategy that has been adopted by the NIF project to …
Date: February 22, 2001
Creator: Kozlowski, M; Demos, S; Wu, Z-L; Wong, J; Penetrante, B & Hrubesh, L
Object Type: Report
System: The UNT Digital Library
Comparison of de-noising techniques for FIRST images (open access)

Comparison of de-noising techniques for FIRST images

Data obtained through scientific observations are often contaminated by noise and artifacts from various sources. As a result, a first step in mining these data is to isolate the signal of interest by minimizing the effects of the contaminations. Once the data has been cleaned or de-noised, data mining can proceed as usual. In this paper, we describe our work in denoising astronomical images from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. We are mining this survey to detect radio-emitting galaxies with a bent-double morphology. This task is made difficult by the noise in the images caused by the processing of the sensor data. We compare three different approaches to de-noising: thresholding of wavelet coefficients advocated in the statistical community, traditional Altering methods used in the image processing community, and a simple thresholding scheme proposed by FIRST astronomers. While each approach has its merits and pitfalls, we found that for our purpose, the simple thresholding scheme worked relatively well for the FIRST dataset.
Date: January 22, 2001
Creator: Fodor, I K & Kamath, C
Object Type: Article
System: The UNT Digital Library
Deuterium Accelerator for Neutron Radiography (open access)

Deuterium Accelerator for Neutron Radiography

None
Date: August 22, 2001
Creator: Rusnak, Brian; Hall, James & Hibbard, Wilthea
Object Type: Article
System: The UNT Digital Library
Evaluation of P/M Ring Gear Using Computed Tomography and Ultrasonic Testing (open access)

Evaluation of P/M Ring Gear Using Computed Tomography and Ultrasonic Testing

Ultrasonic (UT) and computed tomography (CT) evaluation of a P/M ring gear was performed at LLNL to characterize the gear and to determine the relative sensitivity of the two techniques to defects of interest. The features of concern lie at the root of the teeth and in layers along the sides of the teeth. These layers can be detected using metalography but success depends on chance and the number of sections polished. Much of the current focus is on improving the sensitivity of the CT scan and on better ways to evaluate the large data sets obtained. The initial data obtained showed anomalies close to the gear teeth as expected. Later data showed anomalies at other locations and in other orientations. Figure 3 shows a radiograph with vertical and horizontal CT slices through regions with anomalies.
Date: February 22, 2001
Creator: Haskins, J J & Martin, P
Object Type: Report
System: The UNT Digital Library
3(omega) Power Balance Procedure on the NIF (open access)

3(omega) Power Balance Procedure on the NIF

This document defines the detailed NIF full system shot procedure to obtain 8% power balance as specified by the SDR002 3.2.1.04. Because the 48 quads of the NIF will be set up over a period of five years, obtaining power balance will naturally be accomplished in two steps. First, as each quad is brought online, the four laser beams within each quad will be tuned by setting the PABTS splitter ratios so that each beam will give the same laser power on target during low energy square pulse shots. During the quad activation period all of the technical tools and procedures will be developed that are needed for attaining full laser power balance. After the initial settings of the 48 PABTS, if no other tuning is done the overall NIF power balance is expected to be about <15%. In the second step, an iteration procedure with approximately 18 full laser system shots will be needed to obtain 8% power balance by tuning out the remaining systematic differences among the quads to an acceptable small difference of 2% rms (at 3{omega}). This rms difference is smaller than the expected variation of the injection energy or the amplifier gain, and is also …
Date: January 22, 2001
Creator: Glenzer, S.; Jones, O.; Speck, D. R.; Munro, D.; Lerche, R.; Salmon, T. et al.
Object Type: Report
System: The UNT Digital Library
Synthesis and Properties of a New Explosive, 4-Amino-3,5-Dinitro-lH-Pyrazole (LLM-116) (open access)

Synthesis and Properties of a New Explosive, 4-Amino-3,5-Dinitro-lH-Pyrazole (LLM-116)

A novel synthesis of the title compound was achieved by direct amination using Vicarious Nucleophilic Substitution (VNS) methodology. Reaction of 1,1,1-trimethylhydrazinium iodide with 3,5-dinitropyrazole in DMSO produces 4-amino-3,s-dinitro-1H-pyrazole as a 1:1 crystal solvate with DMSO. Recrystallization from water yields the monohydrated crystal. Recrystallization of the monohydrate from butyl acetate yields the compound in pure form. Crystallographic data and results of small-scale safety tests are reported. These data indicate that LLM-116 is a promising candidate as an insensitive high explosive.
Date: May 22, 2001
Creator: Schmidt, R. D.; Lee, G. S.; Pagoria, P. F.; Mitchell, A. R. & Gilardi, R.
Object Type: Report
System: The UNT Digital Library
IEEE 802.11 Wireless LAN Security White Paper (open access)

IEEE 802.11 Wireless LAN Security White Paper

Given the increased productivity and growing popularity of wireless communications in general, and wireless data communications in particular, this paper outlines the protocols, security implications, and architectures of IEEE Std. 802.11-1999 wireless LANs (WLANs) and makes recommendations regarding a phased implementation of WLANs at LLNL. This project is driven by the need for convenient and secure access to the Internet for Laboratory visitors and to the internal network for Laboratory employees. A solid architecture designed with a priority on security will allow LLNL to offer network access in areas where it is traditionally hard to deploy wired networks. It will also enable such services as wireless access for inventory control and convenient network access for conference rooms around LLNL. Wireless network access has the potential to increase productivity by enabling instant access to information.
Date: October 22, 2001
Creator: King, Jason S.
Object Type: Report
System: The UNT Digital Library
Arbitrary Lagrangian-Eulerian Method with Local Structured Adaptive Mesh Refinement for Modeling Shock Hydrodynamics (open access)

Arbitrary Lagrangian-Eulerian Method with Local Structured Adaptive Mesh Refinement for Modeling Shock Hydrodynamics

A new method that combines staggered grid Arbitrary Lagrangian-Eulerian (ALE) techniques with structured local adaptive mesh refinement (AMR) has been developed for solution of the Euler equations. This method facilitates the solution of problems currently at and beyond the boundary of soluble problems by traditional ALE methods by focusing computational resources where they are required through dynamic adaption. Many of the core issues involved in the development of the combined ALEAMR method hinge upon the integration of AMR with a staggered grid Lagrangian integration method. The novel components of the method are mainly driven by the need to reconcile traditional AMR techniques, which are typically employed on stationary meshes with cell-centered quantities, with the staggered grids and grid motion employed by Lagrangian methods. Numerical examples are presented which demonstrate the accuracy and efficiency of the method.
Date: October 22, 2001
Creator: Anderson, R W; Pember, R B & Elliott, N S
Object Type: Article
System: The UNT Digital Library
Hydrodynamic Theory of Atomic Mixing in Multicomponent Gases and Plasmas (open access)

Hydrodynamic Theory of Atomic Mixing in Multicomponent Gases and Plasmas

Atomic mixing in multicomponent gases and plasmas is usually described as a diffusional process. The diffusional description is an approximation to a more general dynamical description in which the motion of each individual species or material is governed by its own momentum equation, with appropriate coupling terms to represent the exchange of momentum between different species. These equations are not new, but they are scattered in the literature. Here we summarize the form of these species momentum equations, and the coupling coefficients therein, in sufficient detail to facilitate their inclusion and use to simulate atomic mixing in hydrodynamics codes.
Date: August 22, 2001
Creator: Ramshaw, J D
Object Type: Report
System: The UNT Digital Library
Carbon Resistor Pressure Gauge Calibration at Low Stresses (open access)

Carbon Resistor Pressure Gauge Calibration at Low Stresses

The 470 Ohm carbon resistor gauge has been used in the stress range up to approximately 4-5 GPa for highly heterogeneous materials and/or divergent flow experiments. The attractiveness of the gauge is due to its rugged nature, simple construction, low cost, reproducibility, and survivability in dynamic events. The associated drawbacks are a long time response to pressure equilibration and gauge resistance hysteresis. In the range below 0.4 GPa, the gauge calibration has been mainly extrapolated into this regime. Because of the need for calibration data within this low stress regime, calibration experiments were performed using a split-Hopkinson bar, drop tower apparatus, and a gas pressure chamber. Since the performance of the gauge at elevated temperatures is a concern, the change in resistance due to heating at atmospheric pressure was also investigated. Details of the various calibration arrangements and the results will be discussed and compared a calibration curve fit to previously published calibration data.
Date: June 22, 2001
Creator: Cunningham, B; Vandersall, K S; Niles, A M; Greenwood, D W; Garcia, F & Forbes, J W
Object Type: Article
System: The UNT Digital Library
Improving development planning in a natural gas storage field through simulation-optimization uncertainty analyses (open access)

Improving development planning in a natural gas storage field through simulation-optimization uncertainty analyses

This is the second of two papers describing the application of simulation-optimization methods to a gas storage field development planning problem. The first paper began by giving a detailed description of the field and earlier efforts to model the effects of selected field development options on the field's productivity. It then outlined the basic steps required to apply a combination of artificial neural networks (ANNs) and the genetic algorithm (GA) to explore a much larger universe of field development planning options. Familiarity with the contents of the first paper is a prerequisite for understanding the material presented in this second paper. The optimized solutions to the planning problem presented in the first paper were based on a deterministic, ''best guess'' view of the field's reservoir properties. However, practical field development planning dictates that at least some of the uncertainties associated with these properties be taken into account. This second paper describes procedures and presents results showing how the ANN-GA approach to optimization can be extended to accommodate three sources of uncertainty pertinent to the field being studied: (1) Alternative hypotheses regarding the permeabilities in a key region of the field; (2) Uncertainty regarding the likely success of remediating existing wells; …
Date: January 22, 2001
Creator: Johnson, V M
Object Type: Report
System: The UNT Digital Library
Using Data Mining to Find Bent-Double Radio Galaxies in the FIRST Survey (open access)

Using Data Mining to Find Bent-Double Radio Galaxies in the FIRST Survey

In this paper, the authors describe the use of data mining techniques to search for radio-emitting galaxies with a bent-double morphology. In the past, astronomers from the FIRST (Faint Images of the Radio Sky at Twenty-cm) survey identified these galaxies through visual inspection. This was not only subjective but also tedious as the on-going survey now covers 8000 square degrees, with each square degree containing about 90 galaxies. In this paper, they describe how data mining can be used to automate the identification of these galaxies. They discuss the challenges faced in defining meaningful features that represent the shape of a galaxy and their experiences with ensembles of decision trees for the classification of bent-double galaxies.
Date: June 22, 2001
Creator: Kamath, C.; Cantu-Paz, E.; Fodor,I & Tang,N A
Object Type: Article
System: The UNT Digital Library
Experimental Design for Laser Produced Shocks in Diamond Anvil Cells (open access)

Experimental Design for Laser Produced Shocks in Diamond Anvil Cells

Laser driven shock measurements have been performed on pre-compressed samples. A diamond anvil cell (DAC) has been used to statically compress water to 1 GPa and then strong shocked with an energetic laser. The use of intense laser irradiation can drive shocks in targets making it possible to study the equation of state (EOS) of samples well into the hundreds of GPQ regime. Generally, such experiments employ a sample initially at normal density and standard pressure. Therefore providing data on the principal Hugoniot. In this experiment the initial state of the sample was varied to provide data off the principal Hugoniot. We report the work that was done on the Vulcan laser and describe a method to achieve off principal Hugoniot data.
Date: June 22, 2001
Creator: Moon, S. J.; Cauble, R.; Collins, G. W.; Celliers, P. M.; Hicks, D.; Da Silva, L. B. et al.
Object Type: Article
System: The UNT Digital Library
Non-Compliance Tracking and Trending at LLNL (open access)

Non-Compliance Tracking and Trending at LLNL

The Criticality Safety Section at LLNL has a formal set of procedures to guide the administrative and technical work of the section. Two of these procedures, ''Response to a Criticality Safety Infraction'' and ''CSG Criticality Safety Non-Compliance and Audit Tracking System,'' provide combined guidance for response, tracking, and trending for procedural non-compliances. Combined with a database, this system provides a framework to systematically respond to, document, track and trend criticality safety non-compliances, as well as audit findings.
Date: August 22, 2001
Creator: Huang, S T & Pearson, J S
Object Type: Article
System: The UNT Digital Library
Noise Performance of the Debuncher Stchastic Cooling Systems (open access)

Noise Performance of the Debuncher Stchastic Cooling Systems

A careful measurement of the system noise performance for all 12 Debuncher stochastic cooling systems has been performed. The opportunity to make the measurement was due to a pickup tank warm up to fix a bad preamplifier. A HP power meter and spectrum analyzer were used to measure the noise power and spectral characteristics of each system. Signals were monitored in the tunnel at the medium level transfer switch, before any variable gain devices. Noise power levels observed ranged between -10 to -30 dBm, which is well within the linear calibration range of the power meter. The noise floor of the power meter was measured to be below -40 dBm. The temperature of the tunnel for the warm measurements was 80 degrees F or 300 Kelvin. The tanks had been at tunnel temperature for weeks when the warm measurement was made. There was no vacuum in the tanks for the warm measurement. The cold temperature of the tanks at liquid helium was 4.5-5 K. 5K was used in the calculations. No component changes were made between the measurements. The gain of the cryogenic amplifier increases with a decrease in operating temperature. The gain of the cryo amplifier was carefully measured …
Date: March 22, 2001
Creator: Pasquinelli, Ralph J.
Object Type: Report
System: The UNT Digital Library
Optimization of the 8 GeV AP3-P1 Lattice for Antiproton Transfers (open access)

Optimization of the 8 GeV AP3-P1 Lattice for Antiproton Transfers

During 8 GeV antiproton transfers between the Accumulator to the Main Injector, the antiprotons must travel through four separate beam lines, AP3, AP1, P2, and P1. This note describes the optimization of a single lattice that describes these beam lines for 8 GeV antiproton transfers from the Accumulator to the Main Injector and 8 GeV proton transfers from the Main Injector to the Accumulator.
Date: January 22, 2001
Creator: McGinnis, Dave
Object Type: Report
System: The UNT Digital Library
FEA Analysis of AP-0 Target Hall Collection Lens (Current Design) (open access)

FEA Analysis of AP-0 Target Hall Collection Lens (Current Design)

The AP-0 Target Hall Collection Lens is a pulsed device which focuses anti-protons just downstream of the Target. Since the angles at which the anti-protons depart the Target can be quite large, a very high focusing strength is required to maximize anti-proton capture into the downstream Debuncher Ring. The current design of the Collection Lens was designed to operate with a focusing gradient of 1,000 T/m. However, multiple failures of early devices resulted in lowering the normal operating gradient to about 750 T/m. At this gradient, the Lens design fares much better, lasting several million pulses, but ultimately still fails. A Finite Element Analysis (FEA) has been performed on this Collection Lens design to help determine the cause and/or nature of the failures. The Collection Lens magnetic field is created by passing high current through a central conductor cylinder. A uniform current distribution through the cylinder will create a tangential or azimuthal magnetic field that varies linearly from zero at the center of the cylinder to a maximum at the outer surface of the cylinder. Anti-proton particles passing through this cylinder (along the longitudinal direction) will see an inward focusing kick back toward the center of the cylinder proportional to …
Date: June 22, 2001
Creator: Hurh, P.G. & Tang, Z.
Object Type: Report
System: The UNT Digital Library
Economic Globalization and a Nuclear Renaissance (open access)

Economic Globalization and a Nuclear Renaissance

The phenomenon of globalization has become increasingly well recognized, documented, and analyzed in the last several years. Globalization, the integration of markets and intra-firm competition on a worldwide basis, involves complex behavioral and mindset changes within a firm that facilitate global competition. The changes revolve around efficient information flow and rapid deployment of technology. The objective of this report is to examine the probable characteristics of a global nuclear renaissance and its broad implications for industry structure and export control relative to nuclear technology. The question of how a modern renaissance would affect the trend toward globalization of the nuclear industry is addressed.
Date: October 22, 2001
Creator: Wood, Thomas W.; Johnson, Wayne L. & Parker, Brian M.
Object Type: Report
System: The UNT Digital Library
In/Si(111): Self-assembled one and two-dimensional electrongases (open access)

In/Si(111): Self-assembled one and two-dimensional electrongases

We present angle-resolved photoemission measurements forultrathin In films on Si(111). Depending on the coverage, this systemself-organizes into a metallic monolayer with either 4x1 or sqrt7 x sqrt3symmetry relative to the substrate. Electronically, they behave likeideal one- and two-dimensional electron gases (1DEG and 2DEG),respectively. The 4x1 system has atomic chains of In whose energy bandsdisperse only parallel to the chains, while for the sqrt7 x sqrt3 system,the dominant reciprocal space features (in both diffraction andbandstructure) resemble a pseudo-square lattice with only weakersecondary features relating to the sqrt7 x sqrt3 periodicity. In bothmaterials the electrons show coupling to the structure. The 1DEG couplesstrongly to phonons of momentum 2kF, leading to an 8x"2" Peierls-likeinsulating ground state. The 2DEG appears to be partially stabilized byelectron gap formation at the sqrt 7 x sqrt3 zone boundary.
Date: January 22, 2001
Creator: Rotenberg, Eli; Yeom, H. W.; Takeda, S.; Matsuda, I.; Horikoshi, K.; Schaefer, J. et al.
Object Type: Article
System: The UNT Digital Library
MCF-10A-NeoST: A New Cell System for Studying Cell-ECM and Cell-Cell Interactions in Breast Cancer (open access)

MCF-10A-NeoST: A New Cell System for Studying Cell-ECM and Cell-Cell Interactions in Breast Cancer

There is a continuing need for genetically matched cell systems to model cellular behaviors that are frequently observed in aggressive breast cancers. We report here the isolation and initial characterization of a spontaneously arising variant of MCF-10A cells, NeoST, which provides a new model to study cell adhesion and signal transduction in breast cancer. NeoST cells recapitulate important biological and biochemical features of metastatic breast cancer, including anchorage-independent growth, invasiveness in threedimensional reconstituted membranes, loss of E-cadherin expression, and increased tyrosine kinase activity. A comprehensive analysis of tyrosine kinase expression revealed overexpression or functional activation of the Axl, FAK, and EphA2 tyrosine kinases in transformed MCF-10A cells. MCF-10A and these new derivatives provide a genetically matched model to study defects in cell adhesion and signaling that are relevant to cellular behaviors that often typify aggressive breast cancer cells.
Date: August 22, 2001
Creator: Zantek, N. D.; Walker-Daniels, J.; Stewart, J.; Hansen, R. K.; Robinson, D.; Miao, H. et al.
Object Type: Article
System: The UNT Digital Library