Modeling the Galaxy Three-Point Correlation Function (open access)

Modeling the Galaxy Three-Point Correlation Function

We present new theoretical predictions for the galaxy three-point correlation function (3PCF) using high-resolution dissipationless cosmological simulations of a flat Lambda CDM Universe which resolve galaxy-size halos and subhalos. We create realistic mock galaxy catalogs by assigning luminosities and colors to dark matter halos and subhalos, and we measure the reduced 3PCF as a function of luminosity and color in both real and redshift space. As galaxy luminosity and color are varied, we find small differences in the amplitude and shape dependence of the reduced 3PCF, at a level qualitatively consistent with recent measurements from the SDSS and 2dFGRS. We confirm that discrepancies between previous 3PCF measurements can be explained in part by differences in binning choices. We explore the degree to which a simple local bias model can fit the simulated 3PCF. The agreement between the model predictions and galaxy 3PCF measurements lends further credence to the straightforward association of galaxies with CDM halos and subhalos.
Date: June 5, 2007
Creator: Marin, Felipe; /Chicago U., Astron. Astrophys. Ctr.; Wechsler, Risa; /Chicago U., Astron. Astrophys. Ctr. /KIPAC, Menlo Park /SLAC; Frieman, Joshua A.; /Chicago U., Astron. Astrophys. Ctr. /Fermilab et al.
Object Type: Article
System: The UNT Digital Library
Can combining economizers with improved filtration save energy and protect equipment in data centers? (open access)

Can combining economizers with improved filtration save energy and protect equipment in data centers?

Economizer use in data centers is an energy efficiency strategy that could significantly limit electricity demand in this rapidly growing economic sector. Widespread economizer implementation, however, has been hindered by potential equipment reliability concerns associated with exposing information technology equipment to particulate matter of outdoor origin. This study explores the feasibility of using economizers in data centers to save energy while controlling particle concentrations with high-quality air filtration. Physical and chemical properties of indoor and outdoor particles were analyzed at an operating northern California data center equipped with an economizer under varying levels of air filtration efficiency. Results show that when improved filtration is used in combination with an economizer, the indoor/outdoor concentration ratios for most measured particle types were similar to levels when using conventional filtration without economizers. An energy analysis of the data center reveals that, even during the summer months, chiller savings from economizer use greatly outweigh any increase in fan power associated with improved filtration. These findings indicate that economizer use combined with improved filtration could reduce data center energy demand while providing a level of protection from particles of outdoor origin similar to that observed with conventional design.
Date: June 5, 2009
Creator: Shehabi, Arman; Ganguly, Srirupa; Gundel, Lara A.; Horvath, Arpad; Kirchstetter, Thomas W.; Lunden, Melissa M. et al.
Object Type: Article
System: The UNT Digital Library
Demonstration of 12 nm resolution Fresnel zone plate lens based soft x-ray microscopy (open access)

Demonstration of 12 nm resolution Fresnel zone plate lens based soft x-ray microscopy

To extend soft x-ray microscopy to a resolution of order 10 nm or better, we developed a new nanofabrication process for Fresnel zone plate lenses. The new process, based on the double patterning technique, has enabled us to fabricate high quality gold zone plates with 12 nm outer zones. Testing of the zone plate with the full-field transmission x-ray microscope, XM-1, in Berkeley, showed that the lens clearly resolved 12 nm lines and spaces. This result represents a significant step towards 10 nm resolution and beyond.
Date: June 5, 2009
Creator: Chao, W.; Kim, J.; Rekawa, S.; Fischer, P. & Anderson, E. H.
Object Type: Article
System: The UNT Digital Library
Network Sensitivity Solutions for Regional Moment Tensor Inversions (open access)

Network Sensitivity Solutions for Regional Moment Tensor Inversions

Well-resolved moment tensor solutions reveal information about the sources of seismic waves. Here we introduce a new way of assessing confidence in the regional full moment tensor inversion via the introduction of the network sensitivity solution (NSS). The NSS takes into account the unique station distribution, frequency band, and signal-to-noise ratio of a given event scenario. The NSS compares both a hypothetical pure source (for example an explosion or an earthquake) and the actual data with several thousand sets of synthetic data from a uniform distribution of all possible sources. The comparison with a hypothetical pure source provides the theoretically best-constrained source-type region for a given set of stations, and with it one can determine whether further analysis with the data is warranted. The NSS that employs the actual data gives a direct comparison of all other source-types with the best-fit source. In this way, one can choose a threshold level of fit where the solution is comfortably constrained. The method is tested for the well-recorded nuclear test, JUNCTION, at the Nevada Test Site. Sources that fit comparably well to a hypothetical pure explosion recorded with no noise at the JUNCTION data stations have a large volumetric component and are …
Date: June 5, 2009
Creator: Ford, S R; Dreger, D S & Walter, W R
Object Type: Article
System: The UNT Digital Library
Secondary Uranium-Phase Paragenesis and Incorporation of Radionuclides into Secondary Phase (open access)

Secondary Uranium-Phase Paragenesis and Incorporation of Radionuclides into Secondary Phase

The purpose of this analysis/model report (AMR) is to assess the potential for uranium (U) (VI) compounds, formed during the oxidative corrosion of spent uranium-oxide (UO{sub 2}) fuels, to sequester certain radionuclides and, thereby, limit their release. The ''unsaturated drip tests'' being conducted at Argonne National Laboratory (ANL) provide the basis of this AMR (Table 1). The ANL drip tests on spent fuel are the only experiments on fuel corrosion from which solids have been analyzed for trace levels of radionuclides. Brief summaries are provided of the results from other selected corrosion and dissolution experiments on spent UO{sub 2} fuels, specifically those conducted under nominally oxidizing conditions. Discussions of the current understanding of thermodynamic and kinetic properties of U(VI) compounds is provided in order to outline the scientific basis for modeling precipitation and dissolution of potential radionuclide-bearing phases under repository-relevant conditions. Attachment I provides additional information on corrosion mechanisms and behaviors of radionuclides in the tests at ANL. Attachment II reviews occurrence, formation, and alteration (collectively known as paragenesis) of naturally occurring U(VI) minerals because natural mineral occurrences can be used to assess the possible long-term behaviors of U(VI) compounds formed in short-term laboratory experiments and to extrapolate experimental results …
Date: June 5, 2001
Creator: Finch, R.
Object Type: Report
System: The UNT Digital Library
Foaming and Antifoaming in Radioactive Waste Pretreatment and Immobilization Processes (open access)

Foaming and Antifoaming in Radioactive Waste Pretreatment and Immobilization Processes

The objective of this research is to develop a fundamental understanding of the physico-chemical mechanisms that cause foaminess in the DOE High Level (HLW) and Low Activity radioactive waste separation processes and to develop and test advanced antifoam/defoaming agents. Antifoams developed for this research will be tested using simulated defense HLW radioactive wastes obtained from the Hanford and Savannah River sites.
Date: June 5, 2003
Creator: Wasan, Darsh T.; Nikolov, Alex; Lambert, Dan & Calloway, T. Bond, Jr.
Object Type: Report
System: The UNT Digital Library
Atomic resolution of lithium ions in LiCoO{sub 2} (open access)

Atomic resolution of lithium ions in LiCoO{sub 2}

LiCoO{sub 2} is the most common lithium storage material used as positive electrode in lithium rechargeable batteries. Ordering of lithium and vacancies has a profound effect on the physical properties of Li{sub x}CoO{sub 2} and the electrochemical performances of lithium batteries. An exit surface wave (ESW) phase image reconstructed from experimental images obtained on the LBNL One-Angstrom Microscope (OAM) shows all three types of atoms in LiCoO{sub 2}.
Date: June 5, 2003
Creator: Shao-Horn, Yang; Croguennec, Laurence; Delmas, Claude; Nelson, E. Chris & O'Keefe, Michael A.
Object Type: Article
System: The UNT Digital Library
X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films (open access)

X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films

None
Date: June 5, 2002
Creator: Richardson, Thomas; Farangis, Baker; Slack, J.L.; Nachimuthu, P.; Perera, R.; Tamura, N. et al.
Object Type: Article
System: The UNT Digital Library
High Frequency Electromagnetic Impedance Imaging for Vadose Zone and Groundwater Characterization (open access)

High Frequency Electromagnetic Impedance Imaging for Vadose Zone and Groundwater Characterization

A geophysical experiment is described for characterizing the clastic dike systems, which are ubiquitous within the vadose zone at the Hanford Nuclear Reservation. because the dikes possess a significant electrical contrast from the insulating host medium, we have applied controlled source audio magnetotelluric (CSAMT) measurements to map their geometric extent and to further clarify if the dike complex acts as a conduit for contaminant transport within the vadose zone. Because of cost and weak natural field signal levels, we employed controlled field sourcing using the STRATGEM acquisition system. Use of artificial fields often goes with the assumption that the data required in the far-field of the transmitter.
Date: June 5, 2003
Creator: Newman, Greory A.; Alumbaugh, David L.; Hoversten, Michael & Nichols, Edward
Object Type: Report
System: The UNT Digital Library
A generic approach to improved semi-solid forming of metals (open access)

A generic approach to improved semi-solid forming of metals

Lack of technology for the production of large inexpensive feedstock, with uniform spherical primary phase throughout as required for semi-solid forming, has restricted realization of the full potential for the semi-solid forming process. Furthermore, narrow process windows and alloy chemistry restrictions increase process costs and limit performance attributes possible with existing semi-solid metal systems. Successful semi-solid forming trials utilizing Chesapeake Composites Corporation's DSC trademark Metals for feedstock indicate that this represents a generic approach to providing a permanent highly uniform, spherical solid phase, without electromagnetic or mechanical shearing. This approach also provides for further growth of semi-solid forming by providing for: low cost large diameter billet stock, reduced semi-solid forming costs, extension of semi-solid forming to new alloy systems, and semi-solid formed components with substantially enhanced physical and mechanical proper ties.
Date: June 5, 2002
Creator: Klier, E. M.
Object Type: Report
System: The UNT Digital Library
Cold Vacuum Drying Instrument Air System Design Description (SYS 12) (open access)

Cold Vacuum Drying Instrument Air System Design Description (SYS 12)

This system design description (SDD) addresses the instrument air (IA) system of the spent nuclear fuel (SNF). This IA system provides instrument quality air to the Cold Vacuum Drying (CVD) Facility. The IA system is a general service system that supports the operation of the heating, ventilation, and air conditioning (HVAC) system, the process equipment skids, and process instruments in the CVD Facility. The following discussion is limited to the compressor, dryer, piping, and valving that provide the IA as shown in Drawings H-1-82222, Cold Vacuum Drying Facility Mechanical Utilities Compressed & Instrument Air P&ID, and H-1.82161, Cold Vacuum Drying Facility Process Equipment Skid P&ID MCO/Cusk Interface. Figure 1-1 shows the physical location of the 1A system in the CVD Facility.
Date: June 5, 2000
Creator: Shapley, B. J. & Tran, Y. S.
Object Type: Report
System: The UNT Digital Library
Parametric Analyses of Heat Removal from High Level Waste Tanks (open access)

Parametric Analyses of Heat Removal from High Level Waste Tanks

The general thermal hydraulics program GOTH-SNF was used to predict the thermal response of the waste in tanks 241-AY-102 and 241-AZ-102 when mixed by two 300 horsepower mixer pumps. This mixing was defined in terms of a specific waste retrieval scenario. Both dome and annulus ventilation system flow are necessary to maintain the waste within temperature control limits during the mixing operation and later during the sludge-settling portion of the scenario are defined.
Date: June 5, 2000
Creator: Truitt, J. B.
Object Type: Report
System: The UNT Digital Library
Distributed Energy Resources at Naval Base Ventura County Building 1512: A Sensitivity Analysis (open access)

Distributed Energy Resources at Naval Base Ventura County Building 1512: A Sensitivity Analysis

This report is the second of a two-part study by BerkeleyLab of a DER (distributed energy resources) system at Navy Base VenturaCounty (NBVC). First, a preliminary assessment ofthe cost effectivenessof distributed energy resources at Naval Base Ventura County (NBVC)Building 1512 was conducted in response to the base s request for designassistance to the Federal Energy Management Program (Bailey and Marnay,2004). That report contains a detailed description of the site and theDER-CAM (Consumer Adoption Model) parameters used. This second reportcontains sensitivity analyses of key parameters in the DER system modelof Building 1512 at NBVC and additionally considers the potential forabsorption-powered refrigeration.The prior analysis found that under thecurrent tariffs, and given assumptions about the performance andstructure of building energy loads and available generating technologycharacteristics, installing a 600 kW DER system with absorption coolingand recovery heat capabilities could deliver cost savings of about 14percent, worth $55,000 per year. However, under current conditions, thisstudy also suggested that significant savings could be obtained ifBuilding 1512 changed from its current direct access contract to a SCETOU-8 (Southern California Edison time of use tariff number 8) ratewithout installing a DER system. Evaluated on this tariff, the potentialsavings from installation of a DER system would be about 4 …
Date: June 5, 2005
Creator: Bailey, Owen C. & Marnay, Chris
Object Type: Report
System: The UNT Digital Library
Controlling the morphology of nanocrystal-polymer composites for solar cells (open access)

Controlling the morphology of nanocrystal-polymer composites for solar cells

None
Date: June 5, 2002
Creator: Huynh, Wendy U.; Dittmer, Janke J.; Libby, William C.; Whiting, Gregory L. & Alivisatos, A. Paul
Object Type: Article
System: The UNT Digital Library
10 (micro)m and 5 (micro)m Pinhole-Assisted Point-Projection Backlit Imaging for NIF (open access)

10 (micro)m and 5 (micro)m Pinhole-Assisted Point-Projection Backlit Imaging for NIF

Pinhole-assisted point-projection backlighting with 10{micro}m and 5 {micro}m pinholes placed a small distance of order 1 mm away from the backlighter produces images with large field of view and high resolution. Pinholes placed closely to high-power backlighter sources can vaporize and close due to x-ray driven ablation, thereby limiting the usefulness of this method. A study of streaked 1-D backlit imaging of 25 {micro}m W wires using the OMEGA laser is presented. The pinhole closure timescale for 10 {micro}m pinholes placed 0.45 mm and 1 mm distant from the backlighter is 1.3 ns and 2.2 ns, respectively. Similar timescales for 5 {micro}m pinholes is also presented. Successful wire imaging prior to pinhole closure is clearly demonstrated.
Date: June 5, 2001
Creator: Bullock, A. B.; Landen, O. L. & Bradley, D. K.
Object Type: Article
System: The UNT Digital Library
Hanford Diversification and the Tri-Cities Economy FY 1999 (open access)

Hanford Diversification and the Tri-Cities Economy FY 1999

The missions of the U.S. Department of Energy's Richland Operations Office (DOE/RL) are to safely manage the Hanford Site, to manage and clean up its legacy wastes, and to develop and deploy new science and technology in the environmental and energy fields. Collectively, DOE/RL and its contractors are the most important single entity in the Tri-Cities local economy (Pasco, Kennewick, and Richland, Washington, and the surrounding area). Although the relevant economic region affected by DOE/RL and its contractors actually embraces a geographic area reaching from Yakima in the west to Walla Walla in the east and from Moses Lake in the north to Pendleton, Oregon, in the south, over 90% of economic impacts likely occur in Benton and Franklin Counties. These two counties are defined as the ''local'' Tri-Cities economy for purposes of this study. In the federal fiscal year (FY) 1999 (October 1, 1998 through September 30, 1999), the total impact of DOE'S local $1.59 billion budget was felt through payrolls of $542 million and local purchases of goods and services of $226 million. The total local spending of $768 million was up slightly from the FY 1998 total of $765 million. Taking into account the multiplier effects of …
Date: June 5, 2000
Creator: Scott, M. J.
Object Type: Report
System: The UNT Digital Library
Nuclear transitions induced by synchrotron x-rays. (open access)

Nuclear transitions induced by synchrotron x-rays.

We discuss two rare but interesting processes by which synchrotron x-rays with energies up to about 100 keV may be used to induce nuclear transitions. In the NEET (Nuclear Excitation by Electronic Transition) process, an intense x-ray beam is employed to make vacancies, e.g. K-holes, in the atoms of a specific nuclear isotope. When a vacancy is filled by an electronic transition from a higher atomic level, there is some probability that instead of the usual x-ray or Auger emission, the nucleus of the atom itself will be excited. This is then followed by a nuclear decay exhibiting characteristic gamma-rays or other types of radiation, with time delays typical of the nuclear states involved. The probability for NEET increases when the energies of the atomic and the nuclear transitions become close. We address some theoretical aspects of the process and describe experimental efforts to observe it in {sup 189}Os and {sup 197}Au. The second process to be discussed is the possibility of ''triggering'' the decay of a nuclear isomer by irradiation with an x-ray beam. We focus on the case of the 31-year, 2.4-MeV, 16+ isomer of {sup 178}Hf. There has been speculation that if one could isolate gram quantities, …
Date: June 5, 2002
Creator: Gemmell, D. S.
Object Type: Article
System: The UNT Digital Library
Radiation levels experienced by the insertion devices of the third-generation synchrotron radiation sources. (open access)

Radiation levels experienced by the insertion devices of the third-generation synchrotron radiation sources.

None
Date: June 5, 2002
Creator: Job, P. K. & Alderman, J.
Object Type: Article
System: The UNT Digital Library
Beam Effects from an Increase of LINAC Current from 40 ma to 49 Milliamperes (open access)

Beam Effects from an Increase of LINAC Current from 40 ma to 49 Milliamperes

On March 25, 2002 the FNAL Linac had been running at a decreased 40 ma of beam current for some time. Both the 400 MeV Linac and the 8GeV Booster had been tuned to optimum running during that time. Optimum running for the Booster was at 4.1e12 per pulse. Losses at injection and at transition were limiting intensity at the time. By March 26, 2002 the Linac beam current had been increased to 49 ma. The optimum Booster intensity immediately jumped to 4.5e12 per pulse and increased in the next few days to 4.8e12 and 5e12 per pulse. Booster was not retuned until early April when a low-loss 5.0e12 was obtained for stacking operations. Linac current had sagged to 47 ma by then. Measurements were made on the 25th at 40 ma and the 26th and 27th at 49 ma. This is a report and discussion of those measurements.
Date: June 5, 2002
Creator: Tomlin, Ray
Object Type: Report
System: The UNT Digital Library
An overview of the Argonne National Laboratory fast critical experiments 1963-1990. (open access)

An overview of the Argonne National Laboratory fast critical experiments 1963-1990.

None
Date: June 5, 2001
Creator: LeSage, L.G.
Object Type: Report
System: The UNT Digital Library
Prediction of Corrosion of Alloys in Mixed-Solvent Environments (open access)

Prediction of Corrosion of Alloys in Mixed-Solvent Environments

Corrosion is much less predictable in organic or mixed-solvent environments than in aqueous process environments. As a result, US chemical companies face greater uncertainty when selecting process equipment materials to manufacture chemical products using organic or mixed solvents than when the process environments are only aqueous. Chemical companies handle this uncertainty by overdesigning the equipment (wasting money and energy), rather than by accepting increased risks of corrosion failure (personnel hazards and environmental releases). Therefore, it is important to develop simulation tools that would help the chemical process industries to understand and predict corrosion and to develop mitigation measures. To create such tools, we have developed models that predict (1) the chemical composition, speciation, phase equilibria, component activities and transport properties of the bulk (aqueous, nonaqueous or mixed) phase that is in contact with the metal; (2) the phase equilibria and component activities of the alloy phase(s) that may be subject to corrosion and (3) the interfacial phenomena that are responsible for corrosion at the metal/solution or passive film/solution interface. During the course of this project, we have completed the following: (1) Development of thermodynamic modules for calculating the activities of alloy components; (2) Development of software that generates stability diagrams …
Date: June 5, 2003
Creator: A. Anderko, P. Wang, R. D. Young, D. P. Riemer, P. McKenzie and M. M. Lencka (OLI Systems Inc.) & Laboratory), S. S. Babu and P. Angelini (Oak Ridge National
Object Type: Report
System: The UNT Digital Library
Strange Goings on in Quark Matter. (open access)

Strange Goings on in Quark Matter.

We review recent work on how the superfluid state of three flavor quark matter is affected by non-zero quark masses and chemical potentials. The study of hadronic matter at high baryon density has recently attracted a lot of interest. At zero baryon density chiral symmetry is broken by a quark-anti-quark condensate. At high density condensation in the quark-anti-quark channel is suppressed. Instead, attractive interactions in the color anti-symmetric quark-quark channel favor the formation of diquark condensates. As a consequence, cold dense quark matter is expected to be a color superconductor. The symmetry breaking pattern depends on the density, the number of quark flavors, and their masses. A particularly symmetric phase is the color-flavor-locked (CFL) phase of three flavor quark matter. This phase is believed to be the true ground state of ordinary matter at very large density.
Date: June 5, 2001
Creator: Schafer, T.
Object Type: Article
System: The UNT Digital Library
A Study of the Effects of Disorder in the 2D Hubbard Model (open access)

A Study of the Effects of Disorder in the 2D Hubbard Model

We study the effects of disorder on long range antiferromagnetic correlations and the Mott gap in the half-filled, two dimensional, repulsive Hubbard model. We employ Hartree-Fock (HF) and Quantum Monte Carlo (QMC) techniques in our study of the bond and site disordered models. Results from mean field (HF) calculations are used to develop a qualitative picture of the physics and to guide our choice for input to the QMC methods. The basic properties of two QMC methods for correlated fermions are discussed, and the results from these different approaches are presented.
Date: June 5, 2000
Creator: Enjalran, M.; Hebert, F.; Scalettar, R.; Zhang, S. & Batrouni, G.
Object Type: Article
System: The UNT Digital Library
Energetic Nanocomposites with Sol-gel Chemistry: Synthesis, Safety, and Characterization (open access)

Energetic Nanocomposites with Sol-gel Chemistry: Synthesis, Safety, and Characterization

The preparation and characterization of energetic composite materials containing nanometer-sized constituents is currently a very active and exciting area of research at laboratories around the world. Some of these efforts have produced materials that have shown very unique and important properties relative to traditional energetic materials. We have previously reported on the use of sol-gel chemical methods to prepare energetic nanocomposites. Primarily we reported on the sol-gel method to synthesize nanometer-sized ferric oxide that was combined with aluminum fuel to make pyrotechnic nanocomposites. Since then we have developed a synthetic approach that allows for the preparation of hybrid inorganic/organic energetic nanocomposites. This material has been characterized by thermal methods, energy-filtered transmission electron microscopy (EFTEM), N{sub 2} adsorption/description methods, and Fourier-Transform (FT-IR) spectroscopy, results of which will be discussed. According to these characterization methods the organic polymer phase fills the nanopores of the composite material, providing superb mixing of the component phases in the energetic nanocomposite. The EFTEM results provide a convenient and effective way to evaluate the intimacy of mixing between these component phases. The safe handling and preparation of energetic nanocomposites is of paramount importance to this research and we will report on studies performed to ensure such.
Date: June 5, 2002
Creator: Gash, A. E.; Simpson, R. L. & Satcher, J. H.
Object Type: Article
System: The UNT Digital Library