2001-2002 Wet Season Branchiopod Survey Report, Lawrence Livermore National Laboratory, Site 300, Alameda and San Joaquin Counties, California (open access)

2001-2002 Wet Season Branchiopod Survey Report, Lawrence Livermore National Laboratory, Site 300, Alameda and San Joaquin Counties, California

Condor County Consulting on behalf of Lawrence Livermore National Laboratory (LLNL) has performed wet season surveys for listed branchiopods at Site 300, located in eastern Alameda County and western San Joaquin County. LLNL is collecting information for the preparation of an EIS covering ongoing explosives testing and related activities on Site 300. Related activities include maintenance of fire roads and annual control burns of approximately 607 hectares (1500 acres). Control burns typically take place on the northern portion of the site. Because natural branchiopod habitat is sparse on Site 300, it is not surprising that listed branchiopods were not observed during this 2001-2002 wet season survey. Although the site is large, a majority of it has topography and geology that precludes the formation of static seasonal pools. Even the relatively gentle topography of the northern half of the site contains few areas where water pools for more than two weeks. The rock outcrops found on the site did not provide suitable habitat for listed branchiopods. Most of the habitat available to branchiopods on the site is puddles that form in roadbeds and dry quickly. The one persistent pool on the site, the larger of the two modified vernal pools and …
Date: November 16, 2004
Creator: Weber, W & Woollett, J
Object Type: Report
System: The UNT Digital Library
2002-2003 Wet Season Branchiopod Survey Report, Lawrence Livermore National Laboratory, Site 300, Alameda and San Joaquin Counties, California (open access)

2002-2003 Wet Season Branchiopod Survey Report, Lawrence Livermore National Laboratory, Site 300, Alameda and San Joaquin Counties, California

Condor Country Consulting conducted surveys for listed branchiopods in the 2002-2003 wet season to complete requirements of the Guidelines (USFWS 1996) used to determine the distribution of federally-listed branchiopods within the study area. The first survey was performed during the previous wet season (2001-2002). The 2002-2003 wet season survey, combined with the previous season's survey, is intended to provide LLNL with information that will assist them in determining the effects of the proposed action on federally listed branchiopods and provide information useful in the preparation of the associated environmental documentation. It is also expected to satisfy the survey requirements of the USFWS. For the purpose of this report, the term branchiopod refers specifically to phyllopodous branchiopods and not cladocerans. Fairy shrimp, tadpole shrimp, and clam shrimp are all categorized as phyllopodous branchiopods and are currently the only members of the Class Branchiopoda that contain species that are listed under the federal Endangered Species Act. Although cladocerans are branchiopods and were found on the site, they are only referred to by the Order in this report because they are not the target species of this study.
Date: November 16, 2004
Creator: Weber, W & Woollett, J
Object Type: Report
System: The UNT Digital Library
2002 Small Mammal Inventory at Lawrence Livermore National Laboratory, Site 300 (open access)

2002 Small Mammal Inventory at Lawrence Livermore National Laboratory, Site 300

To assist the University of California in obtaining biological assessment information for the ''2004 Environmental Impact Statement for Continued Operation of Lawrence Livermore National Laboratory (LLNL)'', Jones & Stokes conducted an inventory of small mammals in six major vegetation communities at Site 300. These communities were annual grassland, native grassland, oak savanna, riparian corridor, coastal scrub, and seep/spring wetlands. The principal objective of this study was to assess the diversity and abundance of small mammal species in these communities, as well as the current status of any special-status small mammal species found in these communities. Surveys in the native grassland community were conducted before and after a controlled fire management burn of the grasslands to qualitatively evaluate any potential effects of fire on small mammals in the area.
Date: November 16, 2004
Creator: West, E & Woollett, J
Object Type: Report
System: The UNT Digital Library
Alfven Eigenmode Stability with Beams in ITER-like Plasma (open access)

Alfven Eigenmode Stability with Beams in ITER-like Plasma

Toroidicity Alfven Eigenmodes (TAE) in ITER can be driven unstable by two groups of energetic particles, the 3.5 MeV {alpha}-particle fusion products and the tangentially injected 1MeV beam ions. Stability conditions are established using the perturbative NOVA/NOVA-K codes. A quasi-linear diffusion model is then used to assess the induced redistribution of energetic particles.
Date: July 16, 2004
Creator: Gorelenkov, N. N.; Berk, H. L. & Budny, R. V.
Object Type: Report
System: The UNT Digital Library
Alliance for Computational Science Collaboration HBCU Partnership at Fisk University. Final Report 2001 (open access)

Alliance for Computational Science Collaboration HBCU Partnership at Fisk University. Final Report 2001

Computational Science plays a big role in research and development in mathematics, science, engineering and biomedical disciplines. The Alliance for Computational Science Collaboration (ACSC) has the goal of training African-American and other minority scientists in the computational science field for eventual employment with the Department of Energy (DOE). The involvements of Historically Black Colleges and Universities (HBCU) in the Alliance provide avenues for producing future DOE African-American scientists. Fisk University has been participating in this program through grants from the DOE. The DOE grant supported computational science activities at Fisk University. The research areas included energy related projects, distributed computing, visualization of scientific systems and biomedical computing. Students' involvement in computational science research included undergraduate summer research at Oak Ridge National Lab, on-campus research involving the participation of undergraduates, participation of undergraduate and faculty members in workshops, and mentoring of students. These activities enhanced research and education in computational science, thereby adding to Fisk University's spectrum of research and educational capabilities. Among the successes of the computational science activities are the acceptance of three undergraduate students to graduate schools with full scholarships beginning fall 2002 (one for master degree program and two for Doctoral degree program).
Date: August 16, 2004
Creator: Collins, W. E.
Object Type: Report
System: The UNT Digital Library
AMR for low Mach number reacting flow (open access)

AMR for low Mach number reacting flow

We present a summary of recent progress on the development and application of adaptive mesh refinement algorithms for low Mach number reacting flows. Our approach uses a form of the low Mach number equations based on a general equation of state that discretely conserves both mass and energy. The discretization methodology is based on a robust projection formulation that accommodates large density contrasts. The algorithm supports modeling of multicomponent systems and incorporates an operator-split treatment of stiff reaction terms. The basic computational approach is embedded in an adaptive projection framework that uses structured hierarchical grids with subcycling in time that preserves the discrete conservation properties of the underlying single-grid algorithm. We present numerical examples illustrating the application of the methodology to turbulent premixed combustion and nuclear flames in type Ia supernovae.
Date: January 16, 2004
Creator: Bell, John B.
Object Type: Article
System: The UNT Digital Library
Analysis of the time-reversal operator for planar dipole arrays (open access)

Analysis of the time-reversal operator for planar dipole arrays

The problem of imaging of targets in random media or cluttered environments is found in a wide variety of different applications, including ocean acoustics, medical ultrasound, geophysics, and radar. The solution often requires separating targets of interest from other scatterers, and compensating for wave speed variations in the medium. The problem is not usually the lack of data, but too much data, specifically the lack of a useful organizing principle for the data. The difficult part is separating the meaningful data from the remainder. It would therefore be most helpful if there were some means for skipping over those parts of the data that we do not really want to image very much, and looking at those parts (targets) that do interest us. This sounds challenging (maybe even impossible), but recent developments in acoustics make it clear that certain very limited imaging goals are achievable with much smaller data sets than are traditionally needed in, for example, seismic array processing. Early versions of this new method have been given the names of ''time-reversal acoustics'' or ''time-reversal mirrors,'' and have been developed most extensively by the French ultrasonics group led by Fink.
Date: January 16, 2004
Creator: Chambers, D H & Berryman, J G
Object Type: Article
System: The UNT Digital Library
An Analytical Model for Solute Transport in Unsaturated Flowthrough a Single Fracture and Porous Rock Matrix (open access)

An Analytical Model for Solute Transport in Unsaturated Flowthrough a Single Fracture and Porous Rock Matrix

Exact analytical solutions are presented for solute transport in an unsaturated fracture and porous rock matrix. The problem includes advective transport in the fracture and rock matrix as well as advective and diffusive fracture-matrix exchange. Linear sorption in the fracture and matrix and radioactive decay are also treated. The solution is for steady, uniform transport velocities within the fracture and matrix, but allows for independent specification of each of the velocities. The problem is first solved in terms of the solute concentrations that result from an instantaneous point source. Superposition integrals are then used to derive the solute mass flux at a fixed downstream position from an instantaneous point source and for the solute concentrations that result from a continuous point source. Solutions are derived for cases with the solute source in the fracture and the solute source in the matrix. The analytical solutions are closed-form and are expressed in terms of algebraic functions, exponentials, and error functions. Comparisons between the analytical solutions and numerical simulations, as well as sensitivity studies, are presented. Increased sensitivity to cross-flow and solute source location is found for increasing Peclet number. The numerical solutions are found to compare well with the analytical solutions at …
Date: September 16, 2004
Creator: Houseworth, J.E.
Object Type: Article
System: The UNT Digital Library
Applied and Environmental Microbiology Gordon Research Conference July 27 - August 1, 2003 (open access)

Applied and Environmental Microbiology Gordon Research Conference July 27 - August 1, 2003

None
Date: April 16, 2004
Creator: Wall, Judy D.
Object Type: Article
System: The UNT Digital Library
Applying synchrotron phase measurement to the estimation of maximum beam intensity in the Fermilab Booster (open access)

Applying synchrotron phase measurement to the estimation of maximum beam intensity in the Fermilab Booster

It is important to have experimental methods to estimate the maximum beam intensity for the Fermilab Booster as objective input into long term program commitments. An important existing limit is set by the available rf power. This limit is difficult to set a priori, because the real longitudinal impedance is not well known. The synchrotron phase at transition crossing was measured using both the mountain range plot and the direct phase measurement of the RF accelerating voltage relative to the beam, and results were consistent. They were applied to predict 6 x 10{sup 12} maximum Booster beam intensity with present running conditions.
Date: March 16, 2004
Creator: Yang, Xi & MacLachlan, James
Object Type: Report
System: The UNT Digital Library
The Astro-E2 XRS/EBIT Microcalorimeter XC-ray Spectrometer (open access)

The Astro-E2 XRS/EBIT Microcalorimeter XC-ray Spectrometer

The X-ray Spectrometer (XRS) instrument is a revolutionary non-dispersive spectrometer that will form the basis for the Astro-E2 observatory to be launched in 2005. We have recently installed a flight spare XRS microcalorimeter spectrometer at the EBIT-I and SuperEBIT facility at LLNL replacing the XRS from the earlier Astro-E mission and providing twice the resolving power. The XRS microcalorimeter is an x-ray detector that senses the heat deposited by the incident photon. It achieves a high energy resolution by operating at 0.06K and by carefully engineering the heat capacity and thermal conductance. The XRS/EBIT instrument has 32 pixels in a square geometry and achieves an energy resolution of 6 eV at 6 keV, with a bandpass from 0.1 to 12 keV (or more at higher operating temperature). The instrument allows detailed studies of the x-ray line emission of laboratory plasmas. The XRS/EBIT also provides an extensive calibration 'library' for the Astro-E2 observatory.
Date: April 16, 2004
Creator: Porter, F S; Brown, G V; Boyce, K R; Kelley, R L; Kilbourne, C A; Beiersdorfer, P et al.
Object Type: Article
System: The UNT Digital Library
Atomic and Molecular Facility at the Advanced Light Source (open access)

Atomic and Molecular Facility at the Advanced Light Source

Atomic physics research using an undulator beamline at the Advanced Light Source (ALS).
Date: April 16, 2004
Creator: Berrah, N.
Object Type: Report
System: The UNT Digital Library
Axial Electron Heat Loss From Mirror Devices Revisited (open access)

Axial Electron Heat Loss From Mirror Devices Revisited

An issue of the axial electron heat loss is of a significant importance for mirror-based fusion devices. This problem has been considered in a number of publications but it is still shrouded in misconceptions. In this paper we revisit it once again. We discuss the following issues: (1) Formation of the electron distribution function in the end tank at large expansion ratios; (2) The secondary emission from the end plates and the ways of suppressing it (if needed); (3) Ionization and charge exchange in the presence of neutrals in the end tanks; (4) Instabilities caused by the peculiar shape of the electron distribution function and their possible impact on the electron heat losses; (5) Electron heat losses in the pulsed mode of operation of mirror devices.
Date: August 16, 2004
Creator: Ryutov, D.
Object Type: Article
System: The UNT Digital Library
Benzene Generation Testing for Tank 48H Waste Disposition (open access)

Benzene Generation Testing for Tank 48H Waste Disposition

In support for the Aggregation option, researchers performed a series of tests using actual Tank 48H slurries. The tests were designed to examine potential benzene generation issues if the Tank 48H slurry is disposed to Saltstone. Personnel used the archived Tank 48H sample (HTF-E-03-127, collected September 17, 2003) for the experiments. The tests included a series of three experiments (Tests A, B, and F) performed in duplicate, giving a total of six experiments. Test A used Tank 48H slurry mixed with approximately 20:1 with Defense Waste Processing Facility (DWPF) Recycle from Tanks 21H and 22H. Test B used Tank 48H slurry mixed with approximately 2.7:1 with DWPF Recycle from Tanks 21H and 22H, while Test F used Tank 48H slurry as-is. Tests A and B occurred at 45 degrees C, while Test F occurred at 55 degrees C. Over a period of 8 weeks, personnel collected samples for analysis, once per week. Each sample was tested with the in-cell gamma counter. The researchers noted a decline in the cesium activity in solution which is attributed to temperature dependence of the complex slurry equilibrium. Selected samples were sent to ADS for potassium, boron, and cesium analysis. The benzene generation rate was …
Date: November 16, 2004
Creator: PETERS, THOMAS
Object Type: Report
System: The UNT Digital Library
Bounds and self-consistent estimates for elastic constants of random polycrystals with hexagonal, trigonal, and tetragonal symmetries (open access)

Bounds and self-consistent estimates for elastic constants of random polycrystals with hexagonal, trigonal, and tetragonal symmetries

Peselnick, Meister, and Watt have developed rigorous methods for bounding elastic constants of random polycrystals based on the Hashin-Shtrikman variational principles. In particular, a fairly complex set of equations that amounts to an algorithm has been presented previously for finding the bounds on effective elastic moduli for polycrystals having hexagonal, trigonal, and tetragonal symmetries. The more analytical approach developed here, although based on the same ideas, results in a new set of compact formulas for all the cases considered. Once these formulas have been established, it is then straightforward to perform what could be considered an analytic continuation of the formulas (into the region of parameter space between the bounds) that can subsequently be used to provide self-consistent estimates for the elastic constants in all cases. These self-consistent estimates are easily shown (essentially by construction) to lie within the bounds for all the choices of crystal symmetry considered. Estimates obtained this way are quite comparable to those found by the Gubernatis and Krumhansl CPA (coherent potential approximation), but do not require any computations of scattering coefficients.
Date: September 16, 2004
Creator: Berger, E. L.
Object Type: Article
System: The UNT Digital Library
Bridging the Gap between Quantum Mechanics and Large-Scale Atomistic Simulation (open access)

Bridging the Gap between Quantum Mechanics and Large-Scale Atomistic Simulation

The prospect of modeling across disparate length and time scales to achieve a predictive multiscale description of real materials properties has attracted widespread research interest in the last decade. To be sure, the challenges in such multiscale modeling are many, and in demanding cases, such as mechanical properties or dynamic phase transitions, multiple bridges extending from the atomic level all the way to the continuum level must be built. Although often overlooked in this process, one of the most fundamental and important problems in multiscale modeling is that of bridging the gap between first-principles quantum mechanics, from which true predictive power for real materials emanates, and the large-scale atomistic simulation of thousands or millions of atoms, which is usually essential to describe the complex atomic processes that link to higher length and time scales. For example, to model single-crystal plasticity at micron length scales via dislocation-dynamics simulations that evolve the detailed dislocation microstructure requires accurate large-scale atomistic information on the mobility and interaction of individual dislocations. Similarly, modeling the kinetics of structural phase transitions requires linking accurate large-scale atomistic information on nucleation processes with higher length and time scale growth processes.
Date: August 16, 2004
Creator: Moriarty, J. A.
Object Type: Book
System: The UNT Digital Library
Calculation of Post-Closure Natural Convection Heat and Mass Transfer in Yucca Mountain Drifts (open access)

Calculation of Post-Closure Natural Convection Heat and Mass Transfer in Yucca Mountain Drifts

Natural convection heat and mass transfer under post-closure conditions has been calculated for Yucca Mountain drifts using the computational fluid dynamics (CFD) code FLUENT. Calculations have been performed for 300, 1000, 3000, and 10,000 years after repository closure. Effective dispersion coefficients that can be used to calculate mass transfer in the drift have been evaluated as a function of time and boundary temperature tilt.
Date: March 16, 2004
Creator: Webb, S. & Itamura, M.
Object Type: Article
System: The UNT Digital Library
Ceramic Coatings for Corrosion Resistant Nuclear Waste Container Evaluated in Simulated Ground Water at 90?C (open access)

Ceramic Coatings for Corrosion Resistant Nuclear Waste Container Evaluated in Simulated Ground Water at 90?C

None
Date: August 16, 2004
Creator: Haslam, J J; Farmer, J C; Hopper, R W & Wilfinger, K R
Object Type: Article
System: The UNT Digital Library
Chemical Interactions in Multimetal/Zeolite Catalysts (open access)

Chemical Interactions in Multimetal/Zeolite Catalysts

This two-year project has led to a significant improvement in the fundamental understanding of the catalytic action of zeolite-supported redox catalysts. It turned out to be essential that we could combine four strategies for the preparation of catalysts containing transition metal (TM) ions in zeolite cavities: (1) ion exchange from aqueous solution; (2) chemical vapor deposition (CVD) of a volatile halide onto a zeolite in its acidic form; (3) solid state ion exchange; and (4) hydrothermal synthesis of a zeolite having TM ions in its lattice, followed by a treatment transporting these ions to ''guest positions''. Technique (2) enables us to position more TM ions into cavities than permitted by the conventional technique (1).viz one positive charge per Al centered tetrahedron in the zeolite lattice. The additional charge is compensated by ligands to the TM ions, for instance in oxo-ions such as (GaO){sup +} or dinuclear [Cu-O-Cu]{sup 2+}. While technique (3) is preferred over CVD where volatile halides are not available, technique (4) leads to rather isolated ''ex lattice'' oxo-ions. Such oxo-ions tend to be mono-nuclear, in contrast to technique (2) which preferentially creates dinuclear oxo-ions of the same TM element. A favorable element for the present research was that …
Date: April 16, 2004
Creator: Sachtler, Wolfgang M. H.
Object Type: Report
System: The UNT Digital Library
CLIMATE CHANGE FUEL CELL PROGRAM (open access)

CLIMATE CHANGE FUEL CELL PROGRAM

ChevronTexaco has successfully operated a 200 kW PC25C phosphoric acid fuel cell power plant at the corporate data center in San Ramon, California for the past two years and seven months following installation in December 2001. This site was chosen based on the ability to utilize the combined heat (hot water) and power generation capability of this modular fuel cell power plant in an office park setting . In addition, this project also represents one of the first commercial applications of a stationary fuel cell for a mission critical data center to assess power reliability benefits. This fuel cell power plant system has demonstrated outstanding reliability and performance relative to other comparably sized cogeneration systems.
Date: September 16, 2004
Creator: Walneuski, Mike
Object Type: Report
System: The UNT Digital Library
Comparison of two up-scaling methods in poroelasticity and its generalizations (open access)

Comparison of two up-scaling methods in poroelasticity and its generalizations

Two methods of up-scaling coupled equations at the microscale to equations valid at the mesoscale and/or macroscale for fluid-saturated and partially saturated porous media are discussed, compared, and contrasted. The two methods are: (1) two-scale and multiscale homogenization, and (2) volume averaging. Both these methods have advantages for some applications and disadvantages for others. For example, homogenization methods can give formulas for coefficients in the up-scaled equations, whereas volume averaging methods give the form of the up-scaled equations but generally must be supplemented with physical arguments and/or data in order to determine the coefficients. Homogenization theory requires a great deal of mathematical insight from the user in order to choose appropriate scalings for use in the resulting power-law expansions, while volume averaging requires more physical insight to motivate the steps needed to find coefficients. Homogenization often is performed on periodic models, while volume averaging does not require any assumption of periodicity and can therefore be related very directly to laboratory and/or field measurements. Validity of the homogenization process is often limited to specific ranges of frequency - in order to justify the scaling hypotheses that must be made - and therefore cannot be used easily over wide ranges of frequency. …
Date: March 16, 2004
Creator: Berger, E. L.
Object Type: Article
System: The UNT Digital Library
Conditions Conducive to Forming Crystalline Uranyl Silicates in High Caustic Nuclear Waste Evaporators (open access)

Conditions Conducive to Forming Crystalline Uranyl Silicates in High Caustic Nuclear Waste Evaporators

The laboratory conditions used to synthesize the uranyl silicate minerals are almost identical to the evaporator conditions under which high caustic nuclear wastes are processed to reduce total liquid waste volume. The only significant difference lies in the sodium ion concentration in such caustic nuclear wastes, which typically averages around 5.6 M Na+. In this investigation, synthetic uranyl silicate minerals (sodium weeksite, sodium boltwoodite and uranophane) were produced only under low Na+ concentration (less than 0.02 M), while attempts to synthesize these same uranyl silicates minerals in the presence of high Na+ concentration (high ionic strength reacting media), which is typical of caustic nuclear waste evaporator processing conditions proved unfruitful. In the presence of high Na+ concentration the main product for the same soluble silica-uranium reaction mixture shifts towards the formation of mainly clarkeite (Na[(UO2)O(OH)](H2O)0-1), a hydrated sodium uranate and not to wards the formation of uranyl silicates. Thus, the presence of high Na+ concentration in the reaction mixture of dissolved uranium and silica inhibits or suppresses the formation of crystalline uranyl silicates. We therefore conclude that evaporator fouling by uranyl silicate minerals is not easily produced under nuclear waste processing conditions because of the high Na+ concentration in the …
Date: November 16, 2004
Creator: OJI, LAWRENCE
Object Type: Report
System: The UNT Digital Library
Core Plasma Charge States of Mo Ions in High Electron Temperature JET and FTU Plasmas (open access)

Core Plasma Charge States of Mo Ions in High Electron Temperature JET and FTU Plasmas

None
Date: June 16, 2004
Creator: Mattioli, M; Carraro, L; Bortolon, A; Coffey, I; Finkenthal, M; Fournier, K et al.
Object Type: Article
System: The UNT Digital Library
Correlation Profiles and Motifs in Complex Networks. (open access)

Correlation Profiles and Motifs in Complex Networks.

Networks have recently emerged as a unifying theme in complex systems research [1]. It is in fact no coincidence that networks and complexity are so heavily intertwined. Any future definition of a complex system should reflect the fact that such systems consist of many mutually interacting components. These components are far from being identical as say electrons in systems studied by condensed matter physics. In a truly complex system each of them has a unique identity allowing one to separate it from the others. The very first question one may ask about such a system is which other components a given component interacts with? This information system wide can be visualized as a graph, whose nodes correspond to individual components of the complex system in question and edges to their mutual interactions. Such a network can be thought of as a backbone of the complex system. Of course, system's dynamics depends not only on the topology of an underlying network but also on the exact form of interaction of components with each other, which can be very different in various complex systems. However, the underlying network may contain clues about the basic design principles and/or evolutionary history of the complex …
Date: January 16, 2004
Creator: Maslov, S.; Sneppen, K. & Alon, U.
Object Type: Book
System: The UNT Digital Library