Resource Type

States

2005 DOE Hydrogen Program Review PresentationCOST AND PERFORMANCE ENHANCEMENTS FOR A PEM FUEL CELL TURBOCOMPRESSOR (open access)

2005 DOE Hydrogen Program Review PresentationCOST AND PERFORMANCE ENHANCEMENTS FOR A PEM FUEL CELL TURBOCOMPRESSOR

The objectives of the program during the past year was to complete Technical Objectives 2 and 3 and initiate Technical Objective 4 are described. To assist the Department of Energy in the development of a low cost, reliable and high performance air compressor/expander. Technical Objective 1: Perform a turbocompressor systems PEM fuel cell trade study to determine the enhanced turbocompressor approach. Technical Objective 2: Using the results from technical objective 1, an enhanced turbocompressor will be fabricated. The design may be modified to match the flow requirements of a selected fuel cell system developer. Technical Objective 3: Design a cost and performance enhanced compact motor and motor controller. Technical Objective 4: Turbocompressor/motor controller development.
Date: April 1, 2005
Creator: Gee, Mark K.
System: The UNT Digital Library
About NICADD extruded scintillating strips (open access)

About NICADD extruded scintillating strips

The results of control measurements of extruded scintillating strip responses to a radioactive source Sr-90 are provided, and details of strip choice, preparation, and method of measurement are included. About four hundred one meter long extruded scintillating strips were measured at four different points. These results were essential for prototyping a tail catcher and muon tracker for a future international electron positron linear collider detector.
Date: April 1, 2005
Creator: Dyshkant, A.; Beznosko, D.; Blazey, G.; Chakraborty, D.; Francis, K.; Kubik, D. et al.
System: The UNT Digital Library
Abundance of Green Tree Frogs and Insects in Artificial Canopy Gaps in a Bottomland Hardwood Forest. (open access)

Abundance of Green Tree Frogs and Insects in Artificial Canopy Gaps in a Bottomland Hardwood Forest.

ABSTRACT - We found more green tree frogs ( Hyla cinerea) n canopv gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopv gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat Flies were the most commonlv collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.
Date: April 1, 2005
Creator: Horn, Scott; Hanula, James, L.; Ulyshen, Michael D. & Kilgo, John, C.
System: The UNT Digital Library
Acceleration and deceleration phase nonlinear Rayleigh-Taylor growth at spherical interfaces (open access)

Acceleration and deceleration phase nonlinear Rayleigh-Taylor growth at spherical interfaces

The Layzer model for the nonlinear evolution of bubbles in the Rayleigh-Taylor instability has recently been generalized to the case of spherically imploding interfaces [D. S. Clark and M. Tabak, to appear, PRE (2005).]. The spherical case is more relevant to, e.g., inertial confinement fusion or various astrophysical phenomena when the convergence is strong or the perturbation wavelength is comparable to the interface curvature. Here, the model is further extended to the case of bubble growth during the deceleration (stagnation) phase of a spherical implosion and to the growth of spikes during both the acceleration and deceleration phases. Differences in the nonlinear growth rates for both bubbles and spikes are found when compared with planar results. The model predictions are verified by comparison with numerical hydrodynamics simulations.
Date: April 8, 2005
Creator: Clark, D S & Tabak, M
System: The UNT Digital Library
Accelerator Mass Spectrometry Allows for Cellular Quantification of Doxorubicin at Femtomolar Concentrations (open access)

Accelerator Mass Spectrometry Allows for Cellular Quantification of Doxorubicin at Femtomolar Concentrations

Accelerator mass spectrometry (AMS) is a highly sensitive analytical methodology used to quantify the content of radioisotopes, such as {sup 14}C, in a sample. The primary goals of this work were to demonstrate the utility of AMS in determining cellular [{sup 14}C]doxorubicin (DOX) concentrations and to develop a sensitive assay that is superior to high performance liquid chromatography (HPLC) for the quantification of DOX at the tumor level. In order to validate the superior sensitivity of AMS versus HPLC with fluorescence detection, we performed three studies comparing the cellular accumulation of DOX: one in vitro cell line study, and two in vivo xenograft mouse studies. Using AMS, we quantified cellular DOX content up to 4 hours following in vitro exposure at concentrations ranging from 0.2 pg/ml (345 fM) to 2 {micro}g/ml (3.45 {micro}M) [{sup 14}C]DOX. The results of this study show that, compared to standard fluorescence-based HPLC, the AMS method was over five orders of magnitude more sensitive. Two in vivo studies compared the sensitivity of AMS to HPLC using a nude mouse xenograft model in which breast cancer cells were implanted subcutaneously. After sufficiently large tumors formed, DOX was administered intravenously at two dose levels. Additionally, we tested the …
Date: April 12, 2005
Creator: DeGregorio, M W; Dingley, K H; Wurz, G T; Ubick, E & Turteltaub, K W
System: The UNT Digital Library
Accelerator mass spectrometry for quantitative in vivo tracing (open access)

Accelerator mass spectrometry for quantitative in vivo tracing

Accelerator mass spectrometry (AMS) counts individual rare, usually radio-, isotopes such as radiocarbon at high efficiency and specificity in milligram-sized samples. AMS traces very low chemical doses ({micro}g) and radiative doses (100 Bq) of isotope labeled compounds in animal models and directly in humans for pharmaceutical, nutritional, or toxicological research. Absorption, metabolism, distribution, binding, and elimination are all quantifiable with high precision after appropriate sample definition.
Date: April 19, 2005
Creator: Vogel, J S
System: The UNT Digital Library
Advanced Test Reactor Testing Experience: Past, Present and Future (open access)

Advanced Test Reactor Testing Experience: Past, Present and Future

The Advanced Test Reactor (ATR), at the Idaho National Laboratory (INL), is one of the world’s premier test reactors for providing the capability for studying the effects of intense neutron and gamma radiation on reactor materials and fuels. The physical configuration of the ATR, a 4-leaf clover shape, allows the reactor to be operated at different power levels in the corner “lobes” to allow for different testing conditions for multiple simultaneous experiments. The combination of high flux (maximum thermal neutron fluxes of 1E15 neutrons per square centimeter per second and maximum fast [E>1.0 MeV] neutron fluxes of 5E14 neutrons per square centimeter per second) and large test volumes (up to 48" long and 5.0" diameter) provide unique testing opportunities. The current experiments in the ATR are for a variety of test sponsors -- US government, foreign governments, private researchers, and commercial companies needing neutron irradiation services. There are three basic types of test configurations in the ATR. The simplest configuration is the sealed static capsule, wherein the target material is placed in a capsule, or plate form, and the capsule is in direct contact with the primary coolant. The next level of complexity of an experiment is an instrumented lead …
Date: April 1, 2005
Creator: Marshall, Frances M.
System: The UNT Digital Library
[After a Fashion, April 21, 2005] (open access)

[After a Fashion, April 21, 2005]

Article about the Women on their Toes benefit, the Austin Museum of Art's annual Art Ball, and other events around Austin, Texas.
Date: April 21, 2005
Creator: Moser, Stephen MacMillan
System: The UNT Digital Library
[After a Fashion Articles, April 2005] (open access)

[After a Fashion Articles, April 2005]

Articles about events that took place in Austin, Texas in April of 2005, including an in memoriam paragraph about John DeLorean.
Date: 2005-04-15/2005-04-21
Creator: Moser, Stephen MacMillan
System: The UNT Digital Library
Air to Blood Distribution of Volatile Organic Compounds: A Linear Free Energy Analysis (open access)

Air to Blood Distribution of Volatile Organic Compounds: A Linear Free Energy Analysis

Article on air to blood distribution of volatile organic compounds and a linear free energy analysis.
Date: April 23, 2005
Creator: Abraham, M. H. (Michael H.); Ibrahim, Adam & Acree, William E. (William Eugene)
System: The UNT Digital Library
Analysis of Radially Resolved Spectra and Potential for Lasing in Mo Wire Array Z Pinches (open access)

Analysis of Radially Resolved Spectra and Potential for Lasing in Mo Wire Array Z Pinches

Measurements of radially resolved L-shell Mo spectra from wire array pinches on Sandia's Z generator are presented and analyzed using a collisional-radiative model. The spectra indicate large radial gradients in density over the {approx}8-mm-diameter plasma column, but only the emission from the {approx}2 mm central region of the pinch appears to be influenced by opacity. Population inversions and significant gain factors for 100-200 {angstrom} transitions in Ne-like Mo are predicted to exist at the diagnosed plasma conditions.
Date: April 29, 2005
Creator: Hansen, S B; Safronova, A S; Apruzese, J P; LePell, P D; Coverdale, C; Deeney, C et al.
System: The UNT Digital Library
Analysis of the Hydrogen Infrastructure Needed to Enable Commercial Introduction of Hydrogen-Fueled Vehicles (open access)

Analysis of the Hydrogen Infrastructure Needed to Enable Commercial Introduction of Hydrogen-Fueled Vehicles

None
Date: April 1, 2005
Creator: Melendez, M.
System: The UNT Digital Library
Angularly resolved measurements of ion energy of vacuum arc plasmas (open access)

Angularly resolved measurements of ion energy of vacuum arc plasmas

None
Date: April 8, 2005
Creator: Anders, Andre & Yushkov, George Yu.
System: The UNT Digital Library
Anisotropic Ellipsoidal Smoothing of Volume Data (open access)

Anisotropic Ellipsoidal Smoothing of Volume Data

This paper describes a simple image processing algorithm for identifying and smoothing cell membranes in tomographic reconstructions of electron micrographs of frozen bacteria.
Date: April 13, 2005
Creator: Xue, Bai; Max, Nelson & Siegerist, Cristina
System: The UNT Digital Library
Anisotropic intermediate valence in Yb2M3Ga9 (M = Rh, Ir) (open access)

Anisotropic intermediate valence in Yb2M3Ga9 (M = Rh, Ir)

The intermediate valence compounds Yb{sub 2}M{sub 3}Ga{sub 9} (M = Rh, Ir) exhibit an anisotropic magnetic susceptibility. We report measurements of the temperature dependence of the 4f occupation number, n{sub f}(T), for Yb{sub 2}M{sub 3}Ga{sub 9} as well as the magnetic inelastic neutron scattering spectrum S{sub mag}({Delta}E) at 12 and 300 K for Yb{sub 2}Rh{sub 3}Ga{sub 9}. Both n{sub f}(T) and S{sub mag}({Delta}E) were calculated for the Anderson impurity model with crystal field terms within an approach based on the non-crossing approximation. These results corroborate the importance of crystal field effects in these materials; they also suggest that Anderson lattice effects are important to the physics of Yb{sub 2}M{sub 3}Ga{sub 9}.
Date: April 26, 2005
Creator: Christianson, A. D.; Lawrence, J. M.; Lobos, A. M.; Aligia, A. A.; Bauer, E. D.; Moreno, N. O. et al.
System: The UNT Digital Library
Anisotropy of electrical conductivity in dry olivine (open access)

Anisotropy of electrical conductivity in dry olivine

[1] The electrical conductivity ({sigma}) was measured for a single crystal of San Carlos olivine (Fo{sub 89.1}) for all three principal orientations over oxygen fugacities 10{sup -7} < fO{sub 2} < 10{sup 1} Pa at 1100, 1200, and 1300 C. Fe-doped Pt electrodes were used in conjunction with a conservative range of fO{sub 2}, T, and time to reduce Fe loss resulting in data that is {approx}0.15 log units higher in conductivity than previous studies. At 1200 C and fO{sub 2} = 10{sup -1} Pa, {sigma}{sub [100]} = 10{sup -2.27} S/m, {sigma}{sub [010]} = 10{sup -2.49} S/m, {sigma}{sub [001]} = 10{sup -2.40} S/m. The dependences of {sigma} on T and fO{sub 2} have been simultaneously modeled with undifferentiated mixed conduction of small polarons and Mg vacancies to obtain steady-state fO{sub 2}-independent activation energies: Ea{sub [100]} = 0.32 eV, Ea{sub [010]} = 0.56 eV, Ea{sub [001]} = 0.71 eV. A single crystal of dry olivine would provide a maximum of {approx}10{sup 0.4} S/m azimuthal {sigma} contrast for T < 1500 C. The anisotropic results are combined to create an isotropic model with Ea = 0.53 eV.
Date: April 13, 2005
Creator: Du Frane, W. L.; Roberts, J. J.; Toffelmier, D. A. & Tyburczy, J. A.
System: The UNT Digital Library
Application of a Java-based, univel geometry, neutral particle Monte Carlo code to the searchlight problem (open access)

Application of a Java-based, univel geometry, neutral particle Monte Carlo code to the searchlight problem

A univel geometry, neutral particle Monte Carlo transport code, written entirely in the Java programming language, is under development for medical radiotherapy applications. The code uses ENDF-VI based continuous energy cross section data in a flexible XML format. Full neutron-photon coupling, including detailed photon production and photonuclear reactions, is included. Charged particle equilibrium is assumed within the patient model so that detailed transport of electrons produced by photon interactions may be neglected. External beam and internal distributed source descriptions for mixed neutron-photon sources are allowed. Flux and dose tallies are performed on a univel basis. A four-tap, shift-register-sequence random number generator is used. Initial verification and validation testing of the basic neutron transport routines is underway. The searchlight problem was chosen as a suitable first application because of the simplicity of the physical model. Results show excellent agreement with analytic solutions. Computation times for similar numbers of histories are comparable to other neutron MC codes written in C and FORTRAN.
Date: April 1, 2005
Creator: Wemple, Charles A. & Cogliati, Joshua J.
System: The UNT Digital Library
Automated Demand Response and Commissioning (open access)

Automated Demand Response and Commissioning

This paper describes the results from the second season of research to develop and evaluate the performance of new Automated Demand Response (Auto-DR) hardware and software technology in large facilities. Demand Response (DR) is a set of activities to reduce or shift electricity use to improve the electric grid reliability and manage electricity costs. Fully-Automated Demand Response does not involve human intervention, but is initiated at a home, building, or facility through receipt of an external communications signal. We refer to this as Auto-DR. The evaluation of the control and communications must be properly configured and pass through a set of test stages: Readiness, Approval, Price Client/Price Server Communication, Internet Gateway/Internet Relay Communication, Control of Equipment, and DR Shed Effectiveness. New commissioning tests are needed for such systems to improve connecting demand responsive building systems to the electric grid demand response systems.
Date: April 1, 2005
Creator: Piette, Mary Ann; Watson, David S.; Motegi, Naoya & Bourassa, Norman
System: The UNT Digital Library
Auxiliary basis expansions for large-scale electronic structure calculations (open access)

Auxiliary basis expansions for large-scale electronic structure calculations

One way to reduce the computational cost of electronic structure calculations is to employ auxiliary basis expansions to approximate 4 center integrals in terms of 2 and 3-center integrals, usually using the variationally optimum Coulomb metric to determine the expansion coefficients. However the long-range decay behavior of the auxiliary basis expansion coefficients has not been characterized. We find that this decay can be surprisingly slow. Numerical experiments on linear alkanes and a toy model both show that the decay can be as slow as 1/r in the distance between the auxiliary function and the fitted charge distribution. The Coulomb metric fitting equations also involve divergent matrix elements for extended systems treated with periodic boundary conditions. An attenuated Coulomb metric that is short-range can eliminate these oddities without substantially degrading calculated relative energies. The sparsity of the fit coefficients is assessed on simple hydrocarbon molecules, and shows quite early onset of linear growth in the number of significant coefficients with system size using the attenuated Coulomb metric. This means it is possible to design linear scaling auxiliary basis methods without additional approximations to treat large systems.
Date: April 4, 2005
Creator: Jung, Yousung; Sodt, Alexander; Gill, Peter W. M. & Head-Gordon, Martin
System: The UNT Digital Library
Background reduction in cryogenic detectors (open access)

Background reduction in cryogenic detectors

This paper discusses the background reduction and rejection strategy of the Cryogenic Dark Matter Search (CDMS) experiment. Recent measurements of background levels from CDMS II at Soudan are presented, along with estimates for future improvements in sensitivity expected for a proposed SuperCDMS experiment at SNOLAB.
Date: April 1, 2005
Creator: Bauer, Daniel A.
System: The UNT Digital Library
A Beamline for High Pressure Studies at the Advanced Light Source With a Superconducting Bending Magnet as the Source (open access)

A Beamline for High Pressure Studies at the Advanced Light Source With a Superconducting Bending Magnet as the Source

A new facility for high-pressure diffraction and spectroscopy using diamond anvil high-pressure cells has been built at the Advanced Light Source on Beamline 12.2.2. This beamline benefits from the hard X-radiation generated by a 6 Tesla superconducting bending magnet (superbend). Useful x-ray flux is available between 5 keV and 35 keV. The radiation is transferred from the superbend to the experimental enclosure by the brightness preserving optics of the beamline. These optics are comprised of: a plane parabola collimating mirror (M1), followed by a Kohzu monochromator vessel with a Si(111) crystals (E/{Delta}E {approx} 7000) and a W/B{sub 4}C multilayer (E/{Delta}E {approx} 100), and then a toroidal focusing mirror (M2) with variable focusing distance. The experimental enclosure contains an automated beam positioning system, a set of slits, ion chambers, the sample positioning goniometry and area detectors (CCD or image-plate detector). Future developments aim at the installation of a second end station dedicated for in situ laser-heating on one hand and a dedicated high-pressure single-crystal station, applying both monochromatic as well as polychromatic techniques.
Date: April 21, 2005
Creator: Kunz, M.; MacDowell, A. A.; Caldwell, W. A.; Cambie, D.; Celestre, R. S.; Domning, E. E. et al.
System: The UNT Digital Library
BEopt: Software for Identifying Optimal Building Designs on the Path to Zero Net Energy; Preprint (open access)

BEopt: Software for Identifying Optimal Building Designs on the Path to Zero Net Energy; Preprint

A zero net energy (ZNE) building produces as much energy on-site as it uses on an annual basis--using a grid-tied, net-metered photovoltaic (PV) system and active solar. The optimal path to ZNE extends from a base case to the ZNE building through a series of energy-saving building designs with minimal energy-related owning and operating costs. BEopt is a computer program designed to find optimal building designs along the path to ZNE. A user selects from among predefined options in various categories to specify options to be considered in the optimization. Energy savings are calculated relative to a reference. The reference can be either a user-defined base-case building or a climate-specific Building America Benchmark building automatically generated by BEopt. The user can also review and modify detailed information on all available options and the Building America Benchmark in a linked options library spreadsheet.
Date: April 1, 2005
Creator: Christensen, C.; Horowitz, S.; Givler, T.; Courtney, A. & Barker, G.
System: The UNT Digital Library
BIBLIOGRAPHIC DATABASES IN SUPPORT OF NSDD EVALUATIONS. (open access)

BIBLIOGRAPHIC DATABASES IN SUPPORT OF NSDD EVALUATIONS.

Bibliographic databases useful to nuclear structure and decay data (NSDD) evaluators are briefly described, along with examples of their usage. Authors' reference listings are also discussed. Nuclear Science References is recognized as the major bibliographic resource, and therefore most of the presentation is devoted to this database.
Date: April 4, 2005
Creator: BURROWS, T.
System: The UNT Digital Library
Bioinformatics for Diagnostics, Forensics, and Virulence Characterization and Detection (open access)

Bioinformatics for Diagnostics, Forensics, and Virulence Characterization and Detection

We summarize four of our group's high-risk/high-payoff research projects funded by the Intelligence Technology Innovation Center (ITIC) in conjunction with our DHS-funded pathogen informatics activities. These are (1) quantitative assessment of genomic sequencing needs to predict high quality DNA and protein signatures for detection, and comparison of draft versus finished sequences for diagnostic signature prediction; (2) development of forensic software to identify SNP and PCR-RFLP variations from a large number of viral pathogen sequences and optimization of the selection of markers for maximum discrimination of those sequences; (3) prediction of signatures for the detection of virulence, antibiotic resistance, and toxin genes and genetic engineering markers in bacteria; (4) bioinformatic characterization of virulence factors to rapidly screen genomic data for potential genes with similar functions and to elucidate potential health threats in novel organisms. The results of (1) are being used by policy makers to set national sequencing priorities. Analyses from (2) are being used in collaborations with the CDC to genotype and characterize many variola strains, and reports from these collaborations have been made to the President. We also determined SNPs for serotype and strain discrimination of 126 foot and mouth disease virus (FMDV) genomes. For (3), currently >1000 probes …
Date: April 5, 2005
Creator: Gardner, S & Slezak, T
System: The UNT Digital Library