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
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
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
Interfacial phenomena on selected cathode materials (open access)

Interfacial phenomena on selected cathode materials

We have carried out a series of surface studies of selected cathode materials. Instrumental techniques such as Raman microscopy, surface enhanced Raman spectroscopy (SERS), and atomic force microscopy were used to investigate the cathode surfaces. The goal of this study was to identify detrimental processes which occur at the electrode/electrolyte interface and can lead to electrode degradation and failure during cycling and/or storage at elevated temperatures.
Date: June 22, 2001
Creator: Kostecki, Robert; Matsuo, Yoshiaki & McLarnon, Frank
Object Type: Report
System: The UNT Digital Library
Superlight gravitinos in electron-photon collisions (open access)

Superlight gravitinos in electron-photon collisions

None
Date: August 22, 2001
Creator: Gopalakrishna, Shrihari & Wells, James
Object Type: Article
System: The UNT Digital Library
Phenomenological two-gap model for the specific heat of MgB2 (open access)

Phenomenological two-gap model for the specific heat of MgB2

The authors show that the specific heat of the superconductor MgB{sub 2} in zero field, for which significant non-BCS features have been reported, can be fitted, essentially within experimental error, over the entire range of temperature to T{sub c} by a phenomenological two-gap model. The resulting gap parameters agree with previous determinations from band-structure calculations, and from various spectroscopic experiments. The determination from specific heat, a bulk property, shows that the presence of two superconducting gaps in MgB{sub 2} is a volume effect.
Date: June 22, 2001
Creator: Bouquet, F.; Wang, Y.; Fisher, R. A.; Hinks, D. G.; Jorgensen, J. D.; Junod, A. et al.
Object Type: Article
System: The UNT Digital Library
GOEMON, a C++ library for accelerator modeling and analysis (open access)

GOEMON, a C++ library for accelerator modeling and analysis

Goemon is a C++ library that supersedes Tracy 2 written in Pascal. It has been continuously developed at ALS since 1993. This paper describes its design and implementation issues, and applications.
Date: June 22, 2001
Creator: Nishimura, Hiroshi
Object Type: Article
System: The UNT Digital Library
Characterization of Prototype Superconducting Magnetic Quadrupolesfor the High Current Transport Experiment (open access)

Characterization of Prototype Superconducting Magnetic Quadrupolesfor the High Current Transport Experiment

Later phases of the High Current Transport Experiment (HCX) at LBNL will employ superconducting magnetic quadrupole lenses to focus an intense, heavy-ion beam over approximately 50 lattice periods (100 quadrupoles). Here they present a characterization of a baseline quadrupole design suitable for transporting a single, low-energy ({approx} 2 MeV), high-current ({approx} 800 mA) heavy-ion (K{sup +}) beam that will be provided from an existing injector and beam matching section. For optimal performance in this application, a compact quadrupole magnet providing high focusing strength and high field quality is required. The reference parameters that they have chosen take into account magnet development work by AML, LLNL, and MIT and result in a transport lattice well matched to programmatic needs with a lattice period of approximately 50 cm. The goal of this note is to introduce a common framework where the magnetic performance of different designs can be compared. In that regard, they try to avoid the details of an earlier parameter note [1] where provisions for tweaks in magnet excitation, cryostat assembly, etc. were discussed in fairly general terms. This note is not intended to be a final specification for the HCX quadrupoles to be constructed or to be the sole …
Date: February 22, 2001
Creator: Lund, Steven M.; Sabbi, GianLuca & Seidl, Peter
Object Type: Report
System: The UNT Digital Library
Nanoscale fabrication and modification of selected battery materials (open access)

Nanoscale fabrication and modification of selected battery materials

Carbon is an integral part of many battery electrodes. We explored the use of semiconductor-processing techniques that involve photolithography to pattern photoresists and subsequent pyrolysis to form carbon microstructures that function as microelectrodes. In this study, we describe the status of the fabrication of carbon microelectrodes obtained by pyrolysis of photoresist. Electrochemical nanometer-scale patterning of the surface of a conducting lithium manganese oxide (LiMn{sub 2}O{sub 4}) by scanning probe microscopy (SPM) was studied. We show that a localized surface chemical change can be confined to a depth which depends on the oxide-tip voltage difference and ambient humidity The ability to produce nanometer-size patterns of chemically modified oxide or nanometer-sized alterations of the oxide morphology is demonstrated and discussed with reference to possible mechanisms.
Date: June 22, 2001
Creator: Kostecki, Robert; Song, Xiang Yun; Kinoshita, Kim & McLarnon, Frank
Object Type: Report
System: The UNT Digital Library
Injection Molding of Plastics from Agricultural Materials (open access)

Injection Molding of Plastics from Agricultural Materials

The objective of this research was to conduct a systematic study to relate injection molding parameters to properties of blends of starch and synthetic polymer. From this study, we wished to develop a thorough understanding of the injection molding process and gain significant insight into designing molds and aiding in developing products cheaply and efficiently.
Date: February 22, 2001
Creator: Bhattacharya, M. & Ruan, R.
Object Type: Report
System: The UNT Digital Library
FIRE HAZARDS ANALYSIS - BUSTED BUTTE (open access)

FIRE HAZARDS ANALYSIS - BUSTED BUTTE

The purpose of this fire hazards analysis (FHA) is to assess the risk from fire within individual fire areas at the Busted Butte Test Facility and to ascertain whether the DOE fire safety objectives are met. The objective, identified in DOE Order 420.1, Section 4.2, is to establish requirements for a comprehensive fire and related hazards protection program for facilities sufficient to minimize the potential for: (1) The occurrence of a fire related event. (2) A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees. (3) Vital DOE programs suffering unacceptable interruptions as a result of fire and related hazards. (4) Property losses from a fire and related events exceeding limits established by DOE. Critical process controls and safety class systems being damaged as a result of a fire and related events.
Date: January 22, 2001
Creator: Longwell, R.; Keifer, J. & Goodin, S.
Object Type: Report
System: The UNT Digital Library
Annual Summary Report Calendar Year 2000 for the 100-HR-3, 100-KR-4, and 100-NR-2 Operable Units and Pump-and-Treat Operations (open access)

Annual Summary Report Calendar Year 2000 for the 100-HR-3, 100-KR-4, and 100-NR-2 Operable Units and Pump-and-Treat Operations

This annual progress and performance evaluation report discusses the groundwater remedial actions in the 100 Area, including the interim actions at the 100-HR-3 and 100-KR-4 Operable Units, and also discusses the expedited response action in the 100-NR-2 operable unit.
Date: August 22, 2001
Creator: Mitchem, G. B.
Object Type: Report
System: The UNT Digital Library
Measurement and Calculation of Electrochemical Potentials in Hydrogenated High Temperature Water, including an Evaluation of the Yttria-Stabilized Zirconia/Iron-Iron Oxide (Fe/Fe3O4) Probe as Reference Electrode (open access)

Measurement and Calculation of Electrochemical Potentials in Hydrogenated High Temperature Water, including an Evaluation of the Yttria-Stabilized Zirconia/Iron-Iron Oxide (Fe/Fe3O4) Probe as Reference Electrode

The importance of knowing the electrochemical corrosion potential (ECP, also referred to as E{sub con}) of nickel-base alloys in hydrogenated water is related to the need to understand the effects of dissolved (i.e., aqueous) hydrogen concentration ([H{sub 2}]) on primary water stress corrosion cracking (PWSCC). Also, the use of a reference electrode (RE) can improve test quality by heightening the ability to detect instances of out-of-specification or unexpected chemistry. Three methods are used to measure and calculate the ECP of nickel-based alloys in hydrogenated water containing {approx} 1 to 150 scc/kg H{sub 2} (0.1 to 13.6 ppm H{sub 2}) at 260 to 360 C. The three methods are referred to as the specimen/component method, the platinum (Pt) method, and the yttria-stabilized zirconia/iron-iron oxide (YSZ/Fe-Fe{sub 3}O{sub 4}) RE method. The specimen/component method relies upon the assumption that the specimen or component behaves as a hydrogen electrode, and its E{sub corr} is calculated using the Nernst equation. The present work shows that this method is valid for aqueous H{sub 2} levels {ge} {approx} 5 to 10 scc/kg H{sub 2}. The Pt method uses a voltage measurement between the specimen or component and a Pt electrode, with the Pt assumed to behave as …
Date: October 22, 2001
Creator: Attanasio, Steven A.; Morton, David S. & Ando, Mark A.
Object Type: Report
System: The UNT Digital Library
Novel joining of dissimilar ceramics in the Si{sub 3}N{sub 4}-Al{sub 2}O{sub 3} system using polytypoid functional gradients (open access)

Novel joining of dissimilar ceramics in the Si{sub 3}N{sub 4}-Al{sub 2}O{sub 3} system using polytypoid functional gradients

A unique approach to crack-free joining of heterogeneous ceramics is demonstrated by the use of sialon polytypoids as Functionally Graded Materials (FGM) as defined by the phase diagram in the system, Si3N4-Al2O3. Polytypoids in the Al2O3-Si3N4 system offer a path to compatibility for such heterogeneous ceramics. The first part of the dissertation describes successful hot press sintering of multilayered FGM's with 20 layers of thickness 500 mm each. Transmission Electron Microscopy was used to identify the polytypoids at the interfaces of different areas of the joint. It has been found that the 15R polytypoid was formed in the Al2O3-contained layers and the 12H polytypoid was formed in the Si3N4-contained layers. The second part of the dissertation discusses the mechanical properties of these polytypoidally joined Si3N4-Al2O3. The thermal stresses of this FGM junction were analyzed using a finite element analysis program (FEAP) taking into account both coefficient of thermal expansion (CTE) and modulus variations. From this analysis, the result showed a dramatic decrease in radial, axial and hoop stresses as the FGM changes from three layers to 20 graded layers. Scaling was considered, showing that the graded transition layer should constitute about 75 percent or more of the total sample thickness …
Date: August 22, 2001
Creator: Lee, Caroline Sunyong
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Modeling Transport in Fractured Porous Media with the Random-Walk Particle Method: The Transient Activity Range and the Particle-Transfer Probability (open access)

Modeling Transport in Fractured Porous Media with the Random-Walk Particle Method: The Transient Activity Range and the Particle-Transfer Probability

Multiscale features of transport processes in fractured porous media make numerical modeling a difficult task, both in conceptualization and computation. Modeling the mass transfer through the fracture-matrix interface is one of the critical issues in the simulation of transport in a fractured porous medium. Because conventional dual-continuum-based numerical methods are unable to capture the transient features of the diffusion depth into the matrix (unless they assume a passive matrix medium), such methods will overestimate the transport of tracers through the fractures, especially for the cases with large fracture spacing, resulting in artificial early breakthroughs. We have developed a new method for calculating the particle-transfer probability that can capture the transient features of diffusion depth into the matrix within the framework of the dual-continuum random-walk particle method (RWPM) by introducing a new concept of activity range of a particle within the matrix. Unlike the multiple-continuum approach, the new dual-continuum RWPM does not require using additional grid blocks to represent the matrix. It does not assume a passive matrix medium and can be applied to the cases where global water flow exists in both continua. The new method has been verified against analytical solutions for transport in the fracture-matrix systems with various …
Date: October 22, 2001
Creator: Pan, Lehua & Bodvarsson, G.S.
Object Type: Report
System: The UNT Digital Library
Strongly Coupled Density-Dependent Flow (open access)

Strongly Coupled Density-Dependent Flow

None
Date: October 22, 2001
Creator: Oldenburg, Curtis M.
Object Type: Article
System: The UNT Digital Library
Supplemental Release Limits for the Directed Reuse of Lead in Shielding Products by the Department of Energy (open access)

Supplemental Release Limits for the Directed Reuse of Lead in Shielding Products by the Department of Energy

The DOE National Center of Excellence for Metals Recycle (NMR) proposes to define and implement a complex-wide directed reuse strategy for surplus radiologically impacted lead (Pb) as part of the U.S. Department of Energy's commitment to the safe and cost-effective recycle or reuse of excess materials and equipment across the DOE complex. NMR will, under this proposal, act on behalf of the DOE Office of Environmental Management, Office of Technical Program Integration (specifically EM-22), as the Department's clearinghouse for DOE surplus lead and lead products by developing and maintaining a cost-effective commercially-based contaminated lead recycle program. It is NMR's intention, through this directed reuse strategy, to mitigate the adverse environmental and economic consequences of managing surplus lead as a waste within the complex. This approach would promote the safe and cost-effective reuse of DOE's scrap and surplus lead in support of the Department's goals of resource utilization, energy conservation, pollution prevention and waste minimization. This report discusses recommendations for supplemental radiological limits for the directed reuse of contaminated lead and lead products by the DOE within the nuclear industry. The limits were selected--with slight modification--from the recently published American National Standards Institute and Health Physics Society standard N13.12 titled Surface …
Date: August 22, 2001
Creator: Coleman, R.L.
Object Type: Report
System: The UNT Digital Library
Carbon microstructures for electrochemical studies (open access)

Carbon microstructures for electrochemical studies

Thin layers of photoresist were spin coated onto silicon wafers, and then carbonized to form smooth carbon films by heating in nitrogen for 1 hour at temperatures between 600 to 1100 C. Well-defined carbon microstructures on Si wafers that are being considered for electrodes in a microbattery concept were obtained by additional processing steps involving patterning and lithography of the photoresist prior to carbonization. The status of the fabrication of carbon microelectrodes obtained by pyrolysis of photoresist, characterization of the carbons by surface-sensitive techniques and electrochemical analysis by cyclic voltammetry of the I{sup -}/I{sub 3}{sup -} redox reaction is described.
Date: June 22, 2001
Creator: Kostecki, Robert; Song, Xiang Yun & Kinoshita, Kim
Object Type: Report
System: The UNT Digital Library
T2LBM Version 1.0: Landfill bioreactor model for TOUGH2 (open access)

T2LBM Version 1.0: Landfill bioreactor model for TOUGH2

The need to control gas and leachate production and minimize refuse volume in landfills has motivated the development of landfill simulation models that can be used by operators to predict and design optimal treatment processes. T2LBM is a module for the TOUGH2 simulator that implements a Landfill Bioreactor Model to provide simulation capability for the processes of aerobic or anaerobic biodegradation of municipal solid waste and the associated flow and transport of gas and liquid through the refuse mass. T2LBM incorporates a Monod kinetic rate law for the biodegradation of acetic acid in the aqueous phase by either aerobic or anaerobic microbes as controlled by the local oxygen concentration. Acetic acid is considered a proxy for all biodegradable substrates in the refuse. Aerobic and anaerobic microbes are assumed to be immobile and not limited by nutrients in their growth. Methane and carbon dioxide generation due to biodegradation with corresponding thermal effects are modeled. The numerous parameters needed to specify biodegradation are input by the user in the SELEC block of the TOUGH2 input file. Test problems show that good matches to laboratory experiments of biodegradation can be obtained. A landfill test problem demonstrates the capabilities of T2LBM for a hypothetical …
Date: May 22, 2001
Creator: Oldenburg, Curtis M.
Object Type: Report
System: The UNT Digital Library