SRNL Emergency Response Capability for Atmospheric Contaminant Releases (open access)

SRNL Emergency Response Capability for Atmospheric Contaminant Releases

Emergency response to an atmospheric release of chemical or radiological contamination is enhanced when plume predictions, field measurements, and real-time weather information are integrated into a geospatial framework. The Weather Information and Display (WIND) System at Savannah River National Laboratory (SRNL) utilizes such an integrated framework. The rapid availability of predictions from a suite of atmospheric transport models within this geospatial framework has proven to be of great value to decision makers during an emergency involving an atmospheric contaminant release.
Date: July 12, 2006
Creator: Koffman, L.; Chuck Hunter, C.; Robert Buckley, R. & Robert Addis, R.
Object Type: Article
System: The UNT Digital Library
SLUDGE BATCH 4 SIMULANT FLOWSHEET STUDIES: PHASE II RESULTS (open access)

SLUDGE BATCH 4 SIMULANT FLOWSHEET STUDIES: PHASE II RESULTS

The Defense Waste Processing Facility (DWPF) will transition from Sludge Batch 3 (SB3) processing to Sludge Batch 4 (SB4) processing in early fiscal year 2007. Tests were conducted using non-radioactive simulants of the expected SB4 composition to determine the impact of varying the acid stoichiometry during the Sludge Receipt and Adjustment Tank (SRAT) process. The work was conducted to meet the Technical Task Request (TTR) HLW/DWPF/TTR-2004-0031 and followed the guidelines of a Task Technical and Quality Assurance Plan (TT&QAP). The flowsheet studies are performed to evaluate the potential chemical processing issues, hydrogen generation rates, and process slurry rheological properties as a function of acid stoichiometry. Initial SB4 flowsheet studies were conducted to guide decisions during the sludge batch preparation process. These studies were conducted with the estimated SB4 composition at the time of the study. The composition has changed slightly since these studies were completed due to changes in the sludges blended to prepare SB4 and the estimated SB3 heel mass. The following TTR requirements were addressed in this testing: (1) Hydrogen and nitrous oxide generation rates as a function of acid stoichiometry; (2) Acid quantities and processing times required for mercury removal; (3) Acid quantities and processing times required …
Date: September 12, 2006
Creator: Stone, M & David Best, D
Object Type: Report
System: The UNT Digital Library
Observations on a Montana Water Quality Proposal. (open access)

Observations on a Montana Water Quality Proposal.

In May 2005, a group of petitioners led by the Northern Plains Resource Council (NPRC) submitted a petition to revise water quality requirements to the Montana Board of Environmental Review (BER). Under Montana law, the BER had to consider the petition and either reject it or propose it as a new regulation. In September 2005, the BER announced proposed changes to the Montana water quality regulations. The proposal, which included almost the exact language found in the petition, was directed toward discharges of water from coal bed natural gas (CBNG) production. The key elements of the proposal included: (1) No discharges of CBNG water are allowed to Montana surface waters unless operators can demonstrate that injection to aquifers with the potential for later recovery of the water is not feasible. (2) When operators can demonstrate the injection is not feasible, the CBNG water to be discharged must meet very strict technology-based limits for multiple parameters. (3) The Montana water quality standards for the sodium adsorption ratio (SAR) and electrical conductivity (EC) would be evaluated using the 7Q10 flow (lowest 7-consecutive-day flow in a 10-year period) rather than a monthly flow that is currently used. (4) SAR and EC would be …
Date: January 12, 2006
Creator: Veil, J. A. & Puder, M. G.
Object Type: Report
System: The UNT Digital Library
Benchmark Studies of Induced Radioactivity Produced in LHC Materials, Pt II Specific Activities (open access)

Benchmark Studies of Induced Radioactivity Produced in LHC Materials, Pt II Specific Activities

A new method to estimate remanent dose rates, to be used with the Monte Carlo code FLUKA, was benchmarked against measurements from an experiment that was performed at the CERN-EU high-energy reference field facility. An extensive collection of samples of different materials were placed downstream of and laterally to a copper target, intercepting a positively charged mixed hadron beam with a momentum of 120 GeV/c. Emphasis was put on the reduction of uncertainties such as careful monitoring of the irradiation parameters, the use of different instruments to measure dose rates, detailed elemental analyses of the irradiated materials and detailed simulations of the irradiation experiment. Measured and calculated dose rates are in good agreement.
Date: April 12, 2006
Creator: Brugger, M.; Mayer, S.; Roesler, S.; Ulrici, L.; Khater, H.; Prinz, A. et al.
Object Type: Article
System: The UNT Digital Library
Explosion Source Phenomena Using Soviet, Test-Era, Waveform Data (open access)

Explosion Source Phenomena Using Soviet, Test-Era, Waveform Data

During the nuclear testing era, the former Soviet Union carried out extensive observations of underground nuclear explosions, recording both their own shots and those of foreign nuclear states. Between 1961 and 1989, the Soviet Complex Seismological Expedition deployed seismometers at time-varying subsets of over 150 sites to record explosions at regional distances from the Semipalatinsk and Lop Nor test sites and from the shot points of peaceful nuclear explosions. This data set included recordings from broadband, multi-channel ChISS seismometers that produced a series of narrow band outputs, which could then be measured to perform spectral studies. [ChISS is the Russian abbreviation for multichannel spectral seismometer. In this instrument the signal from the seismometer is passed through a system of narrow bandpass filters and recorded on photo paper. ChISS instruments have from 8 to 16 channels in the frequency range from 100 sec to 40 Hz. We used data mostly from 7 channels, ranging from 0.08 to 5 Hz.] Quantitative, pre-digital era investigations of high-frequency source scaling relied on this type of data. To augment data sets of central Central Asia explosions, we have measured and compiled 537 ChISS coda envelopes for 124 events recorded at Talgar, Kazakhstan, at a distance …
Date: April 12, 2006
Creator: Richards, Paul G.; Rautian, Tatyana G.; Khalturin, Vitaly I. & Phillips, W. Scott
Object Type: Report
System: The UNT Digital Library
Hose Instability and Wake Generation By An Intense Electron Beam in a Self-Ionized Gas (open access)

Hose Instability and Wake Generation By An Intense Electron Beam in a Self-Ionized Gas

The propagation of an intense relativistic electron beam through a gas that is self-ionized by the beam's space charge and wakefields is examined analytically and with 3D particle-in-cell simulations. Instability arises from the coupling between a beam and the offset plasma channel it creates when it is perturbed. The traditional electron hose instability in a preformed plasma is replaced with this slower growth instability depending on the radius of the ionization channel compared to the electron blowout radius. A new regime for hose stable plasma wakefield acceleration is suggested.
Date: April 12, 2006
Creator: Deng, S.; Barnes, C. D.; Clayton, C. E.; O'Connell, C.; Decker, F. J.; Fonseca, R. A. et al.
Object Type: Article
System: The UNT Digital Library
Comparison of Kinetic and Equilibrium Reaction Models inSimulating the Behavior of Gas Hydrates in Porous Media (open access)

Comparison of Kinetic and Equilibrium Reaction Models inSimulating the Behavior of Gas Hydrates in Porous Media

In this study we compare the use of kinetic and equilibrium reaction models in the simulation of gas (methane) hydrates in porous media. Our objective is to evaluate through numerical simulation the importance of employing kinetic versus equilibrium reaction models for predicting the response of hydrate-bearing systems to external stimuli, such as changes in pressure and temperature. Specifically, we (1) analyze and compare the responses simulated using both reaction models for production in various geological settings and for the case of depressurization in a core during extraction; and (2) examine the sensitivity to factors such as initial hydrate saturation, hydrate reaction surface area, and numerical discretization. We find that for systems undergoing thermal stimulation and depressurization, the calculated responses for both reaction models are remarkably similar, though some differences are observed at early times. Given these observations, and since the computational demands for the kinetic reaction model far exceed those for the equilibrium reaction model, the use of the equilibrium reaction model often appears to be justified and preferred for simulating the behavior of gas hydrates.
Date: May 12, 2006
Creator: Kowalsky, Michael B. & Moridis, George J.
Object Type: Article
System: The UNT Digital Library
Air convection noise of pencil-beam interferometer for long traceprofiler (open access)

Air convection noise of pencil-beam interferometer for long traceprofiler

In this work, we investigate the effect of air convection onlaser-beam pointing noise essential for the long trace profiler (LTP). Wedescribe this pointing error with noise power density (NPD) frequencydistributions. It is shown that the NPD spectra due to air convectionhave a very characteristic form. In the range of frequencies from ~;0.05Hz to ~;0.5 Hz, the spectra can be modeled with an inverse-power-lawfunction. Depending on the intensity of air convection that is controlledwith a resistive heater of 100 to 150 mW along a one-meter-long opticalpath, the power index lies between 2 and 3 at an overall rms noise of~;0.5 to 1 microradian. The efficiency of suppression of the convectionnoise by blowing air across the beam optical path is also discussed.Air-blowing leads to a white-noise-like spectrum. Air blowing was appliedto the reference channel of an LTP allowing demonstration of thecontribution of air convection noise to the LTP reference beam. Theability to change (with the blowing technique presented) the spectralcharacteristics of the beam pointing noise due to air convection allowsone to investigate the contribution of the convection effect, and thusmake corrections to the power spectral density spectra measured with theLTP.
Date: July 12, 2006
Creator: Yashchuk, Valeriy V.; Irick, Steve C.; MacDowell, Alastair A.; McKinney, Wayne R. & Takacs, Peter Z.
Object Type: Article
System: The UNT Digital Library
BPM Motors in Residential Gas Furnaces: What are theSavings? (open access)

BPM Motors in Residential Gas Furnaces: What are theSavings?

Residential gas furnaces contain blowers to distribute warm air. Currently, furnace blowers use either a Permanent Split Capacitor (PSC) or a Brushless Permanent Magnet (BPM) motor. Blowers account for the majority of furnace electricity consumption. Therefore, accurate determination of the blower electricity consumption is important for understanding electricity consumption of furnaces. The electricity consumption of blower motors depends on the static pressure across the blower. This paper examines both types of blower motors in non-condensing non-weatherized gas furnaces at a range of static pressures. Fan performance data is based on manufacturer product literature and laboratory tests. We use field-measured static pressure in ducts to get typical system curves to calculate how furnaces would operate in the field. We contrast this with the electricity consumption of a furnace blower operating under the DOE test procedure and manufacturer rated conditions. Furnace electricity use is also affected by operating modes that happen at the beginning and end of each furnace firing cycle. These operating modes are the pre-purge and post-purge by the draft inducer, the on-delay and off-delay of the blower, and the hot surface ignitor operation. To accurately calculate this effect, we use the number of firing cycles in a typical California …
Date: May 12, 2006
Creator: Lutz, James; Franco, Victor; Lekov, Alex & Wong-Parodi, Gabrielle
Object Type: Article
System: The UNT Digital Library
Sonochemical Digestion of High-Fired Plutonium Dioxide Samples (open access)

Sonochemical Digestion of High-Fired Plutonium Dioxide Samples

This work was performed as part of a broader effort to automate analytical methods for determining plutonium and other radioisotopes in environmental samples. The work described here represented a screening study to evaluate the effect of applying ultrasonic irradiation to dissolve high-fired plutonium oxide. The major findings of this work can be summarized as follows: (1) High-fired plutonium oxide does not undergo measurable dissolution when sonicated in nitric acid solutions, even at a high concentration range of nitric acid where the calculated thermodynamic solubility of plutonium oxide exceeds the ?g/mL level. (2) Applying organic complexants (nitrilotriacetic acid) and reductants (hydroxyurea) in 1.5 M nitric acid does not significantly increase the dissolution compared with digestion in nitric acid alone. Nearly all (99.5%) of the plutonium oxide remains undissolved under these conditions. (3) The action of a strong inorganic reductant, titanium trichloride in 25 wt% HCl, results in 40% dissolution of the plutonium oxide when the titanium trichloride concentration is ?1 wt% under sonication. (4) Oxidative treatment of plutonium oxide by freshly dissolved AgO ({approx}20 mg/mL) in 1.5 M nitric acid with sonication resulted in 95% plutonium oxide dissolution. However, the same treatment of plutonium oxide mechanically mixed with 50 mg of …
Date: October 12, 2006
Creator: Sinkov, Sergei I. & Lumetta, Gregg J.
Object Type: Report
System: The UNT Digital Library
Sonochemical Digestion of Soil and Sediment Samples (open access)

Sonochemical Digestion of Soil and Sediment Samples

This work was performed as part of a broader effort to automate analytical methods for determination of plutonium and other radioisotopes in environmental samples. The work described here represented a screening study to determine the potential for applying ultrasonic irradiation to sample digestion. Two standard reference materials (SRMs) were used in this study: Columbia River Sediment and Rocky Flats Soil. The key experiments performed are listed below along with a summary of the results. The action of nitric acid, regardless of its concentration and liquid-to-solid ratio, did not achieve dissolution efficiency better that 20%. The major fraction of natural organic matter (NOM) remained undissolved by this treatment. Sonication did not result in improved dissolution for the SRMs tested. The action of hydrofluoric acid at concentrations of 8 M and higher achieved much more pronounced dissolution (up to 97% dissolved for the Rocky Flats soil sample and up to 78% dissolved for the Columbia River Sediment sample). Dissolution efficiency remains constant for solid-to-liquid ratios of up to 0.05 to 1 and decreases for the higher loadings of the solid phase. Sonication produced no measurable effect in improving the dissolution of the samples compared with the control digestion experiments. Combined treatment of …
Date: October 12, 2006
Creator: Sinkov, Sergei I. & Lumetta, Gregg J.
Object Type: Report
System: The UNT Digital Library
Simulation of the ILC Collimation System using BDSIM, MARS15 and STRUCT (open access)

Simulation of the ILC Collimation System using BDSIM, MARS15 and STRUCT

None
Date: July 12, 2006
Creator: Carter, J.; Agapov, I.; Blair, G. A.; Deacon, L.; Drozhdin, A. I.; Mokhov, N. V. et al.
Object Type: Article
System: The UNT Digital Library
Crevice Corrosion on Ni-Cr-Mo Alloys (open access)

Crevice Corrosion on Ni-Cr-Mo Alloys

Ni-Cr-Mo alloys were developed for their exceptional corrosion resistance in a variety of extreme corrosive environments. An alloy from this series, Alloy-22, has been selected as the reference material for the fabrication of nuclear waste containers in the proposed Yucca Mountain repository located in Nevada (US). A possible localized corrosion process under the anticipated conditions at this location is crevice corrosion. therefore, it is necessary to assess how this process may, or may not, propagate if the use of this alloy is to be justified. Consequently, the primary objective is the development of a crevice corrosion damage function that can be used to assess the evolution of material penetration rates. They have been using various electrochemical methods such as potentiostatic, galvanostatic and galvanic coupling techniques. Corrosion damage patterns have been investigated using surface analysis techniques such as scanning electron microscopy (SEM) and optical microscopy. All crevice corrosion experiments were performed at 120 C in 5M NaCl solution. Initiating crevice corrosion on these alloys has proven to be difficult; therefore, they have forced it to occur under either potentiostatic or galvanostatic conditions.
Date: May 12, 2006
Creator: Jakupi, P.; Zagidulin, D.; Noel, J. J. & Shoesmith, D. W.
Object Type: Report
System: The UNT Digital Library
A Resource Assessment Of Geothermal Energy Resources For Converting Deep Gas Wells In Carbonate Strata Into Geothermal Extraction Wells: A Permian Basin Evaluation (open access)

A Resource Assessment Of Geothermal Energy Resources For Converting Deep Gas Wells In Carbonate Strata Into Geothermal Extraction Wells: A Permian Basin Evaluation

Previously conducted preliminary investigations within the deep Delaware and Val Verde sub-basins of the Permian Basin complex documented bottom hole temperatures from oil and gas wells that reach the 120-180C temperature range, and occasionally beyond. With large abundances of subsurface brine water, and known porosity and permeability, the deep carbonate strata of the region possess a good potential for future geothermal power development. This work was designed as a 3-year project to investigate a new, undeveloped geographic region for establishing geothermal energy production focused on electric power generation. Identifying optimum geologic and geographic sites for converting depleted deep gas wells and fields within a carbonate environment into geothermal energy extraction wells was part of the project goals. The importance of this work was to affect the three factors limiting the expansion of geothermal development: distribution, field size and accompanying resource availability, and cost. Historically, power production from geothermal energy has been relegated to shallow heat plumes near active volcanic or geyser activity, or in areas where volcanic rocks still retain heat from their formation. Thus geothermal development is spatially variable and site specific. Additionally, existing geothermal fields are only a few 10’s of square km in size, controlled by the …
Date: October 12, 2006
Creator: Erdlac, Richard J., Jr.
Object Type: Report
System: The UNT Digital Library
Characterization of Bacterial Spores by NanoSIMS (open access)

Characterization of Bacterial Spores by NanoSIMS

None
Date: June 12, 2006
Creator: Weber, Peter K.; Ghosal, Sutapa; Hutcheon, Ian D.; Leighton, Terrace & Wheeler, Katie
Object Type: Article
System: The UNT Digital Library
The 2mrad Crossing Angle Interaction Region and Extraction Line (open access)

The 2mrad Crossing Angle Interaction Region and Extraction Line

A complete optics design for the 2mrad crossing angle interaction region and extraction line was presented at Snowmass 2005. Since this time, the design task force has been working on developing and improving the performance of the extraction line. The work has focused on optimizing the final doublet parameters and on reducing the power losses resulting from the disrupted beam transport. In this paper, the most recent status of the 2mrad layout and the corresponding performance are presented.
Date: July 12, 2006
Creator: Appleby, R.; U., Manchester; Angal-Kalinin, D.; Tech, /Cockcroft Inst. Accel. Sci.; Dadoun, O.; Bambade, P. et al.
Object Type: Article
System: The UNT Digital Library
Effects of Test Temperature on Flow of Metallic Glasses (open access)

Effects of Test Temperature on Flow of Metallic Glasses

Micro-hardness experiments were conducted over a range of temperatures using a Nikon QM micro-hardness machine on a number of metallic glass (e.g. Zr-, Fe-, Al-) systems. Although high micro-hardness was exhibited at room temperature, significant hardness reductions were exhibited near the glass transition temperature, T{sub g}. The effects of changes in test temperature on the micro-hardness will be reported. The effects of exposure time on the hardness evolution at a given temperature will also be summarized to illustrate some of the differences in behavior of the systems shown. The extreme softening near T{sub g}, characteristic of bulk metallic glass systems, enables the exploration of novel deformation processing. In order to develop deformation processing windows, the evaluation of bulk metallic glass mechanical properties under quasi-static conditions and the determination of flow properties at different temperatures and strain rates are reported. The use of such information to create layered/composite bulk metallic glasses will be summarized.
Date: April 12, 2006
Creator: Nouri, A. S.; Liu, Y.; Wesseling, P. & Lewandowski, J.
Object Type: Report
System: The UNT Digital Library
Benchmark Studies of Induced Radioactivity Produced in LHC Materials, Pt I: Remanent Dose Rates (open access)

Benchmark Studies of Induced Radioactivity Produced in LHC Materials, Pt I: Remanent Dose Rates

Samples of materials which will be used in the LHC machine for shielding and construction components were irradiated in the stray radiation field of the CERN-EU high-energy reference field facility. After irradiation, the specific activities induced in the various samples were analyzed with a high-precision gamma spectrometer at various cooling times, allowing identification of isotopes with a wide range of half-lives. Furthermore, the irradiation experiment was simulated in detail with the FLUKA Monte Carlo code. A comparison of measured and calculated specific activities shows good agreement, supporting the use of FLUKA for estimating the level of induced activity in the LHC.
Date: April 12, 2006
Creator: Brugger, M.; Mayer, S.; Roesler, S.; Ulrici, L.; Khater, H.; Prinz, A. et al.
Object Type: Article
System: The UNT Digital Library
Prompt and Afterglow Emission Properties of Gamma-Ray Bursts with Spectroscopically Identified Supernovae (open access)

Prompt and Afterglow Emission Properties of Gamma-Ray Bursts with Spectroscopically Identified Supernovae

We present a detailed spectral analysis of the prompt and afterglow emission of four nearby long-soft gamma-ray bursts (GRBs 980425, 030329, 031203, and 060218) that were spectroscopically found to be associated with type Ic supernovae, and compare them to the general GRB population. For each event, we investigate the spectral and luminosity evolution, and estimate the total energy budget based upon broadband observations. The observational inventory for these events has become rich enough to allow estimates of their energy content in relativistic and sub-relativistic form. The result is a global portrait of the effects of the physical processes responsible for producing long-soft GRBs. In particular, we find that the values of the energy released in mildly relativistic outflows appears to have a significantly smaller scatter than those found in highly relativistic ejecta. This is consistent with a picture in which the energy released inside the progenitor star is roughly standard, while the fraction of that energy that ends up in highly relativistic ejecta outside the star can vary dramatically between different events.
Date: July 12, 2006
Creator: Kaneko, Yuki; Ramirez-Ruiz, E.; Granot, J.; Kouveliotou, C.; Woosley, S. E.; Patel, S. K. et al.
Object Type: Report
System: The UNT Digital Library
Near-Core and In-Core Neutron Radiation Monitors for Real Time Neutron Flux Monitoring and Reactor Power Level Measurements (open access)

Near-Core and In-Core Neutron Radiation Monitors for Real Time Neutron Flux Monitoring and Reactor Power Level Measurements

MPFDs are a new class of detectors that utilize properties from existing radiation detector designs. A majority of these characteristics come from fission chamber designs. These include radiation hardness, gamma-ray background insensitivity, and large signal output.
Date: June 12, 2006
Creator: McGregor, Douglas S.; Adams, Marvin L.; Carron, Igor & Nelson, Paul
Object Type: Report
System: The UNT Digital Library
Residential Two-Stage Gas Furnaces - Do They Save Energy? (open access)

Residential Two-Stage Gas Furnaces - Do They Save Energy?

Residential two-stage gas furnaces account for almost a quarter of the total number of models listed in the March 2005 GAMA directory of equipment certified for sale in the United States. Two-stage furnaces are expanding their presence in the market mostly because they meet consumer expectations for improved comfort. Currently, the U.S. Department of Energy (DOE) test procedure serves as the method for reporting furnace total fuel and electricity consumption under laboratory conditions. In 2006, American Society of Heating Refrigeration and Air-conditioning Engineers (ASHRAE) proposed an update to its test procedure which corrects some of the discrepancies found in the DOE test procedure and provides an improved methodology for calculating the energy consumption of two-stage furnaces. The objectives of this paper are to explore the differences in the methods for calculating two-stage residential gas furnace energy consumption in the DOE test procedure and in the 2006 ASHRAE test procedure and to compare test results to research results from field tests. Overall, the DOE test procedure shows a reduction in the total site energy consumption of about 3 percent for two-stage compared to single-stage furnaces at the same efficiency level. In contrast, the 2006 ASHRAE test procedure shows almost no difference …
Date: May 12, 2006
Creator: Lekov, Alex; Franco, Victor & Lutz, James
Object Type: Article
System: The UNT Digital Library
The Tariff Analysis Project: A Database and Analysis Platform for Electricity Tariffs (open access)

The Tariff Analysis Project: A Database and Analysis Platform for Electricity Tariffs

Much of the work done in energy research involves ananalysis of the costs and benefits of energy-saving technologies andother measures from the perspective of the consumer. The economic valuein particular depends on the price of energy (electricity, gas or otherfuel), which varies significantly both for different types of consumers,and for different regions of the country. Ideally, to provide accurateinformation about the economic value of energy savings, prices should becomputed directly from real tariffs as defined by utility companies. Alarge number of utility tariffs are now available freely over the web,but the complexity and diversity of tariff structures presents aconsiderable barrier to using them in practice. The goal of the TariffAnalysis Project (TAP) is to collect andarchive a statistically completesample of real utility tariffs, and build a set of database and web toolsthat make this information relatively easy to use in cost-benefitanalysis. This report presentsa detailed picture of the current TAPdatabase structure and web interface. While TAP has been designed tohandle tariffs for any kind of utility service, the focus here is onelectric utilities withinthe United States. Electricity tariffs can bevery complicated, so the database structures that have been built toaccommodate them are quite flexible and can be easily generalized toother …
Date: May 12, 2006
Creator: Coughlin, K.; White, R.; Bolduc, C.; Fisher, D. & Rosenquist, G.
Object Type: Report
System: The UNT Digital Library
Performance of low-rank QR approximation of the finite element Biot-Savart law (open access)

Performance of low-rank QR approximation of the finite element Biot-Savart law

We are concerned with the computation of magnetic fields from known electric currents in the finite element setting. In finite element eddy current simulations it is necessary to prescribe the magnetic field (or potential, depending upon the formulation) on the conductor boundary. In situations where the magnetic field is due to a distributed current density, the Biot-Savart law can be used, eliminating the need to mesh the nonconducting regions. Computation of the Biot-Savart law can be significantly accelerated using a low-rank QR approximation. We review the low-rank QR method and report performance on selected problems.
Date: January 12, 2006
Creator: White, D. A. & Fasenfest, B. J.
Object Type: Article
System: The UNT Digital Library
First Results from IceCube (open access)

First Results from IceCube

IceCube is a 1 km{sup 3} neutrino observatory being built to study neutrino production in active galactic nuclei, gamma-ray bursts, supernova remnants, and a host of other astrophysical sources. High-energy neutrinos may signal the sources of ultra-high energy cosmic rays. IceCube will also study many particle-physics topics: searches for WIMP annihilation in the Earth or the Sun, and for signatures of supersymmetry in neutrino interactions, studies of neutrino properties, including searches for extra dimensions, and searches for exotica such as magnetic monopoles or Q-balls. IceCube will also study the cosmic-ray composition. In January, 2005, 60 digital optical modules (DOMs) were deployed in the South Polar ice at depths ranging from 1450 to 2450 meters, and 8 ice-tanks, each containing 2 DOMs were deployed as part of a surface air-shower array. All 76 DOMs are collecting high-quality data. After discussing the IceCube physics program and hardware, I will present some initial results with the first DOMs.
Date: January 12, 2006
Creator: Klein, Spencer R.
Object Type: Article
System: The UNT Digital Library