202 Matching Results

Search Results

Results: 1 - 24 next
open access

Raman Spectroscopy of UH3 from the Hydrogen Corrosion of Uranium

Description: Hydrogen reacts with a uranium surface to form a fine, pyrophoric metal power (UH{sub 3}). Few spectroscopic studies have been conducted to study this reaction. Advances in Raman spectroscopy permit the application of the Raman method to formally difficult areas of chemistry such as the hydrogen corrosion of uranium: availability of multiple laser excitation wavelengths; fiber optics delivery and collection systems; upgraded instrumentation and detection techniques; and development of special e… more
Date: May 31, 2011
Creator: Smyrl, N. R.; Stowe, A. C. & Powell, G. L.
Partner: UNT Libraries Government Documents Department
open access

Density Functional Theory in Surface Chemistry and Catalysis

Description: Recent advances in the understanding of reactivity trends for chemistry at transition metal surfaces have enabled in silico design of heterogeneous catalysts in a few cases. Current status of the field is discussed with an emphasis on the role of coupling between theory and experiment and future challenges.
Date: May 19, 2011
Creator: Norskov, Jens
Partner: UNT Libraries Government Documents Department
open access

Retrocausal Effects as a Consequence of Quantum Mechanics Refined to Accommodate the Principle of Sufficient Reason

Description: The principle of sufficient reason asserts that anything that happens does so for a reason: no definite state of affairs can come into being unless there is a sufficient reason why that particular thing should happen. This principle is usually attributed to Leibniz, although the first recorded Western philosopher to use it was Anaximander of Miletus. The demand that nature be rational, in the sense that it be compatible with the principle of sufficient reason, conflicts with a basic feature of … more
Date: May 10, 2011
Creator: Stapp, Henry P.
Partner: UNT Libraries Government Documents Department
open access

A study of extraterrestrial antineutrino sources with the KamLAND detector

Description: We present the results of a search for extraterrestrial electron antineutrinos ({bar {nu}}{sub e}'s) in the energy range 8.3 MeV < E{sub {bar {nu}}}{sub e} < 30.8 MeV using the KamLAND detector. In an exposure of 4.53 kton-year, we identify 25 candidate events. All of the candidate events can be attributed to background, most importantly neutral current atmospheric neutrino interactions, setting an upper limit on the probability of {sup 8}B solar {nu}{sub e}'s converting into {bar {nu}}{s… more
Date: May 18, 2011
Creator: Collaboration, The KamLAND; Gando, A.; Gando, Y.; Ichimura, K.; Ikeda, H.; Inoue, K. et al.
Partner: UNT Libraries Government Documents Department
open access

Analysis of nuclear proliferation resistance reprocessing and recycling technologies

Description: The PUREX process has been progressively and continuously improved during the past three decades, and these improvements account for successful commercialization of reprocessing in a few countries. The renewed interest in nuclear energy and the international growth of nuclear electricity generation do not equate – and should not be equated -with increasing proliferation risks. Indeed, the nuclear renaissance presents a unique opportunity to enhance the culture of non-proliferation. With the rec… more
Date: May 1, 2011
Creator: Paviet-Hartmann, Patricia; Cerefice, Gary; Stacey, Marcela & Bakhtiar, Steven
Partner: UNT Libraries Government Documents Department
open access

Iterative Algorithms for Ptychographic Phase Retrieval

Description: Ptychography promises diffraction limited resolution without the need for high resolution lenses. To achieve high resolution one has to solve the phase problem for many partially overlapping frames. Here we review some of the existing methods for solving ptychographic phase retrieval problem from a numerical analysis point of view, and propose alternative methods based on numerical optimization.
Date: May 3, 2011
Creator: Yang, Chao; Qian, Jianliang; Schirotzek, Andre; Maia, Filipe & Marchesini, Stefano
Partner: UNT Libraries Government Documents Department
open access

Searches for new physics at the Tevatron

Description: The Tevatron collider has provided the CDF and D0 experiences with large datasets as input to a rich program of searches for physics beyond the standard model. The results presented here are a partial survey of recent searches conducted by the two collaborations using up to 6 fb{sup -1} of data. The standard model (SM) of particles, despite its remarkable description of experimental data at the elementary particle level, has some deficiencies to explain what is observed in the universe: lack of… more
Date: May 1, 2011
Creator: Jaffre, Michel
Partner: UNT Libraries Government Documents Department
open access

Real-time Studies of Shocked Polycrystalline Materials with Single-Pulse X-ray Diffraction

Description: Characteristic K-α x-rays used for single-pulse XRD are conventionally produced by a 37-stage high-voltage Marx pulse generator coupled to a vacuum needle-and-washer x-ray diode via coaxial transmission line. A large field-of-view x-ray image plate detection system typically enables observation of several Debye-Scherrer rings. Recently, we have developed a fiber-optic reducer, coupled to a CCD camera, to obtain low-noise, large field-of-view images. The direct beam spot is produced by bremsstra… more
Date: May 25, 2011
Creator: Morgan, Dane V.
Partner: UNT Libraries Government Documents Department
open access

How Common are the Magellanic Clouds

Description: We introduce a probabilistic approach to the problem of counting dwarf satellites around host galaxies in databases with limited redshift information. This technique is used to investigate the occurrence of satellites with luminosities similar to the Magellanic Clouds around hosts with properties similar to the Milky Way in the object catalog of the Sloan Digital Sky Survey. Our analysis uses data from SDSS Data Release 7, selecting candidate Milky-Way-like hosts from the spectroscopic catalog … more
Date: May 20, 2011
Creator: Liu, Lulu; Gerke, Brian F.; Wechsler, Risa H.; Behroozi, Peter S.; Busha, Michael T. & /KIPAC, Menlo Park /SLAC
Partner: UNT Libraries Government Documents Department
open access

Lithium Wall Conditioning And Surface Dust Detection On NSTX

Description: Lithium evaporation onto NSTX plasma facing components (PFC) has resulted in improved energy confinement, and reductions in the number and amplitude of edge-localized modes (ELMs) up to the point of complete ELM suppression. The associated PFC surface chemistry has been investigated with a novel plasma material interface probe connected to an in-vacuo surface analysis station. Analysis has demonstrated that binding of D atoms to the polycrystalline graphite material of the PFCs is fundamentally… more
Date: May 23, 2011
Creator: Skinner, C. H.; Bell, M. G.; Friesen, F. Q. L.; Heim, B.; Jaworski, M. A.; Kugel, H. et al.
Partner: UNT Libraries Government Documents Department
open access

Creep-fatigue of High Temperature Materials for VHTR: Effect of Cyclic Loading and Environment

Description: Alloy 617 is the one of the leading candidate materials for Intermediate Heat eXchangers (IHX) of a Very High Temperature Reactor (VHTR). System start-ups and shut-downs as well as power transients will produce low cycle fatigue (LCF) loadings of components. Furthermore, the anticipated IHX operating temperature, up to 950°C, is in the range of creep so that creep-fatigue interaction, which can significantly increase the fatigue crack growth, may be one of the primary IHX damage modes. To addre… more
Date: May 1, 2011
Creator: Cabet, Celine; Carroll, L.; Wright, R. & Madland, R.
Partner: UNT Libraries Government Documents Department
open access

Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems

Description: Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (radioactive and hazardous) wastes. Test programs performed in recent years have shown that mercury in off-gas streams from processes that treat radioactive wastes can be controlled using fixed beds of activated sulfur-impregnated carbon, to levels low enough to comply with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable … more
Date: May 1, 2011
Creator: Soelberg, Nick & Enneking, Joe
Partner: UNT Libraries Government Documents Department
open access

Max Tech Appliance Design: Potential for Maximizing U.S. Energy Savings through Standards

Description: This study surveyed the technical potential for efficiency improvements in 150 categories of appliances and equipment representing 33 quads of primary energy use across the US economy in 2010 and (1) documented efficient product designs, (2) identified the most promising cross-cutting strategies, and (3) ranked national energy savings potential by end use. Savings were estimated using a method modeled after US Department of Energy priority-setting reports - simplified versions of the full techn… more
Date: May 6, 2011
Creator: Garbesi, Karina; Desroches, Louis-Benoit; Bolduc, Christopher; Burch, Gabriel; Hosseinzadeh, Griffin & Saltiel, Seth
Partner: UNT Libraries Government Documents Department
open access

Ekpyrosis and inflationary dynamics in heavy ion collisions: the role of quantum fluctuations

Description: We summarize recent significant progress in the development of a first-principles formalism to describe the formation and evolution of matter in very high energy heavy ion collisions. The key role of quantum fluctuations both before and after a collision is emphasized. Systematic computations are now feasible to address early time isotropization, flow, parton energy loss and the Chiral Magnetic Effect.
Date: May 23, 2011
Creator: Dusling, K.; Venugopalan, R. & Gelis, F.
Partner: UNT Libraries Government Documents Department
open access

Secondary Pollutants from Ozone Reaction with Ventilation Filters and Degradation of Filter Media Additives

Description: Prior research suggests that chemical processes taking place on the surface of particle filters employed in buildings may lead to the formation of harmful secondary byproducts. We investigated ozone reactions with fiberglass, polyester, cotton/polyester and polyolefin filter media, as well as hydrolysis of filter media additives. Studies were carried out on unused media, and on filters that were installed for 3 months in buildings at two different locations in the San Francisco Bay Area. Specim… more
Date: May 1, 2011
Creator: Destaillats, Hugo; Chen, Wenhao; Apte, Michael; Li, Nuan; Spears, Michael; Almosni, Jérémie et al.
Partner: UNT Libraries Government Documents Department
open access

A Low Carbon Development Guide for Local Government Actions in China

Description: Local level actions are crucial for achieving energy-saving and greenhouse gas emission reduction targets. Yet it is challenging to implement new policies and actions due to a lack of information, funding, and capacity. This is particularly the case in developing countries such as China. Even though national energy intensity and carbon intensity targets have been set, most local governments do not have the knowledge regarding actions to achieve the targets, the cost-effectiveness of policies, t… more
Date: May 1, 2011
Creator: Zheng, Nina; Zhou, Nan; Price, Lynn & Ohshita, Stephanie
Partner: UNT Libraries Government Documents Department
open access

Rapidly Moving Divertor Plates In A Tokamak

Description: It may be possible to replace conventional actively cooled tokamak divertor plates with a set of rapidly moving, passively cooled divertor plates on rails. These plates would absorb the plasma heat flux with their thermal inertia for ~10-30 sec, and would then be removed from the vessel for processing. When outside the tokamak, these plates could be cooled, cleaned, recoated, inspected, and then returned to the vessel in an automated loop. This scheme could provide nearoptimal divertor surfaces… more
Date: May 16, 2011
Creator: Zweben, S.
Partner: UNT Libraries Government Documents Department
open access

The Structural Disorder and Lattice Stability of (Ba,Sr)(Co,Fe)O3 Complex Perovskites

Description: The structural disorder and lattice stability of complex perovskite (Ba,Sr)(Co,Fe)O3, a promising cathode material for solid oxide fuel cells and oxygen permeation membranes, is explored by means of first principles DFT calculations. It is predicted that Ba and Sr ions easily exchange their lattice positions (A-cation disorder) similarly to Co and Fe ions (B-cation disorder). The cation antisite defects (exchange of A- and B-type cations) have a relatively high formation energy. The BSCF is pre… more
Date: May 1, 2011
Creator: S.N.Rashkeev
Partner: UNT Libraries Government Documents Department
open access

On scale and magnitude of pressure build-up induced by large-scale geologic storage of CO2

Description: The scale and magnitude of pressure perturbation and brine migration induced by geologic carbon sequestration is discussed assuming a full-scale deployment scenario in which enough CO{sub 2} is captured and stored to make relevant contributions to global climate change mitigation. In this scenario, the volumetric rates and cumulative volumes of CO{sub 2} injection would be comparable to or higher than those related to existing deep-subsurface injection and extraction activities, such as oil pro… more
Date: May 1, 2011
Creator: Zhou, Q. & Birkholzer, J. T.
Partner: UNT Libraries Government Documents Department
open access

Assessment of the Economic Potential of Microgrids for Reactive Power Supply

Description: As power generation from variable distributed energy resources (DER) grows, energy flows in the network are changing, increasing the requirements for ancillary services, including voltage support. With the appropriate power converter, DER can provide ancillary services such as frequency control and voltage support. This paper outlines the economic potential of DERs coordinated in a microgrid to provide reactive power and voltage support at its point of common coupling. The DER Customer Adoption… more
Date: May 1, 2011
Creator: Appen, Jan von; Marnay, Chris; Stadler, Michael; Momber, Ilan; Klapp, David & Scheven, Alexander von
Partner: UNT Libraries Government Documents Department
open access

Using an Energy Performance Based Design-Build Process to Procure a Large Scale Low-Energy Building: Preprint

Description: This paper will review a procurement, acquisition, and contract process of a large-scale replicable net zero energy (ZEB) office building. The owners developed and implemented an energy performance based design-build process to procure a 220,000 ft2 office building with contractual requirements to meet demand side energy and LEED goals. We will outline the key procurement steps needed to ensure achievement of our energy efficiency and ZEB goals. The development of a clear and comprehensive Requ… more
Date: May 1, 2011
Creator: Pless, S.; Torcellini, P. & Shelton, D.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen