148 Matching Results

Search Results

Results: 1 - 24 next
open access

Oxidation of alloys targeted for advanced steam turbines

Description: Ultra supercritical (USC) power plants offer the promise of higher efficiencies and lower emissions. Current goals of the U.S. Department of Energy’s Advanced Power Systems Initiatives include coal generation at 60% efficiency, which would require steam temperatures of up to 760°C. This research examines the steamside oxidation of alloys for use in USC systems, with emphasis placed on applications in high- and intermediate-pressure turbines.
Date: March 12, 2006
Creator: Holcomb, G. R.; Covino, B. S., Jr.; Bullard, S. J.; Ziomek-Moroz, M. & Alman, D. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Convergence Analysis of a Domain Decomposition Paradigm

Description: We describe a domain decomposition algorithm for use in several variants of the parallel adaptive meshing paradigm of Bank and Holst. This algorithm has low communication, makes extensive use of existing sequential solvers, and exploits in several important ways data generated as part of the adaptive meshing paradigm. We show that for an idealized version of the algorithm, the rate of convergence is independent of both the global problem size N and the number of subdomains p used in the domain … more
Date: June 12, 2006
Creator: Bank, R E & Vassilevski, P S
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

TOUGH+/GasH20 study of the effects of a heat source buried in theMartian permafrost

Description: We use TOUGH+/GasH2O to study the effects of a heat sourceburied in the Martian permafrost to evaluate the possibility ofestablishing a wet zone of liquid water, in which terrestrialmicroorganisms could survive and multiply. Analysis of the problemindicates that (1) only a limited permafrost volume (not exceeding 0.35 min radius) is affected, (2) a "wet" zone with limited amounts of liquidwater de-velops (not exceeding 8 and 0.7 kg for a 250 W and a 62.5 Wsource, respectively), (3) the wet zone… more
Date: May 12, 2006
Creator: Moridis, George J. & Pruess, Karsten
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Improved Technology To Prevent Nuclear Proliferation And Counter Nuclear Terrorism

Description: As the world moves into the 21st century, the possibility of greater reliance on nuclear energy will impose additional technical requirements to prevent proliferation. In addition to proliferation resistant reactors, a careful examination of the various possible fuel cycles from cradle to grave will provide additional technical and nonproliferation challenges in the areas of conversion, enrichment, transportation, recycling and waste disposal. Radiation detection technology and information mana… more
Date: June 12, 2006
Creator: Richardson, J; Yuldashev, B; Labov, S & Knapp, R
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Disorder and size effects on Kondo interactions and magnetic correlations in CePt2 nanoscrystals

Description: The evolution of the Kondo effect and magnetic correlations with size reduction in CePt{sub 2} nanoparticles (3.1-26 nm) is studied by analysis of the temperature-dependent specific heat and magnetic susceptibility. The antiferromagnetic correlations diminish with size reduction. The Kondo effect predominates at small particle size with trivalent, small Kondo temperature (T{sub K}) magnetic regions coexisting with strongly mixed valent, large T{sub K} nonmagnetic regions. We discuss the role of… more
Date: December 12, 2006
Creator: Chen, Y. Y.; Huang, P. H.; Ou, M. N.; Wang, C. R.; Yao, Y. D.; Lee, T. K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Design and Evaluation of Ionic Liquids as Novel CO2 Absorbents

Description: Progress from the fourth quarter 2005 activity on the project ''Design and Evaluation of Ionic Liquids as Novel CO{sub 2} Absorbents'' is provided. Major activities in three areas are reported: compound synthesis, property measurement and molecular modeling. Last quarter we reported the first ever experimental measurement of SO{sub 2} solubility in an ionic liquid. We showed that SO{sub 2} was very soluble in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([hmim… more
Date: January 12, 2006
Creator: Maginn, Edward J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Evaluation of the DRAGON Code for VHTR Design Analysis.

Description: This letter report summarizes three activities that were undertaken in FY 2005 to gather information on the DRAGON code and to perform limited evaluations of the code performance when used in the analysis of the Very High Temperature Reactor (VHTR) designs. These activities include: (1) Use of the code to model the fuel elements of the helium-cooled and liquid-salt-cooled VHTR designs. Results were compared to those from another deterministic lattice code (WIMS8) and a Monte Carlo code (MCNP). … more
Date: January 12, 2006
Creator: Taiwo, T. A. & Kim, T. K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Experimental Tests Of Paleoclassical Transport

Description: Predictions of the recently developed paleoclassical transport model are compared with data from many toroidal plasma experiments: electron heat diffusivity in DIII-D, C-Mod and NSTX ohmic and near-ohmic plasmas; transport modeling of DIII-D ohmic-level discharges and of the RTP ECH 'stair-step' experiments with eITBs at low order rational surfaces; investigation of a strong eITB in JT-60U; H-mode Te edge pedestal properties in DIII-D; and electron heat diffusivities in non-tokamak experiments … more
Date: September 12, 2006
Creator: Callen, J. D.; Anderson, J. K.; Arlen, T. C.; Bateman, G.; Budny, R. V.; Fujita, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

CO2 Sequestration and Recycle by Photosynthesis

Description: Hydrocarbon oxygenate synthesis from photocatalytic reactions of CO{sub 2} and H{sub 2}O over various catalysts is a very attractive process. However, the formation rate of the hydrocarbons and oxygenates is significantly lower than conventional catalysis. One possible reason for the low rate of product formation is the presence of oxidation sites which reoxidize the products back to CO{sub 2} and H{sub 2}O. For further improvement of catalytic activity for the reduction process, it is essentia… more
Date: February 12, 2006
Creator: Chuang, Steven S.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

SRNL Emergency Response Capability for Atmospheric Contaminant Releases

Description: 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 va… more
Date: July 12, 2006
Creator: Koffman, L.; Chuck Hunter, C.; Robert Buckley, R. & Robert Addis, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

SLUDGE BATCH 4 SIMULANT FLOWSHEET STUDIES: PHASE II RESULTS

Description: 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… more
Date: September 12, 2006
Creator: Stone, M & David Best, D
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

Description: The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to a… more
Date: May 12, 2006
Creator: Kennel, Elliot B.; Bergen, R. Michael; Carpenter, Stephen P.; Dadyburjor, Dady; Katakdaunde, Manoj; Magean, Liviu et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Screening Program Reduced Melanoma Mortality at the Lawrence Livermore National Laboratory, 1984-1996

Description: Worldwide incidence of cutaneous malignant melanoma has increased substantially, and no screening program has yet demonstrated reduction in mortality. We evaluated the education, self examination and targeted screening campaign at the Lawrence Livermore National Laboratory (LLNL) from its beginning in July 1984 through 1996. The thickness and crude incidence of melanoma from the years before the campaign were compared to those obtained during the 13 years of screening. Melanoma mortality during… more
Date: October 12, 2006
Creator: Schneider, MD, J S; II, PhD, D & MD, PhD, M
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Cleanup Verification Package for the 618-3 Burial Ground

Description: This cleanup verification package documents completion of remedial action for the 618-3 Solid Waste Burial Ground, also referred to as Burial Ground Number 3 and the Dry Waste Burial Ground Number 3. During its period of operation, the 618-3 site was used to dispose of uranium-contaminated construction debris from the 311 Building and construction/demolition debris from remodeling of the 313, 303-J and 303-K Buildings.
Date: September 12, 2006
Creator: Appel, M. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Visualization of Fiber Structurein the Left and Right Ventricleof a Human Heart

Description: The human heart is composed of a helical network of musclefibers. Anisotropic least squares filtering followed by fiber trackingtechniques were applied to Diffusion Tensor Magnetic Resonance Imaging(DTMRI) data of the excised human heart. The fiber configuration wasvisualized by using thin tubes to increase 3-dimensional visualperception of the complex structure. All visualizations were performedusing the high-quality ray-tracing software POV-Ray. The fibers are shownwithin the left and right v… more
Date: July 12, 2006
Creator: Rohmer, Damien; Sitek, Arkadiusz & Gullberg, Grant T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM 2.5) Fraction of Coal Combustion Ash

Description: During this reporting period, efforts focused on improving our understanding of the basic operating principles of the lamella classifier. It was determined from testing that product grade is primarily a function of the classifier configuration and operation and the feed grade has relatively minor influence. Additionally, within the range of the testing conducted, the feed density did not seem to have an impact of the yield. Thus, the product composition will not be strongly influenced by the va… more
Date: May 12, 2006
Creator: Robl, T.L.; Groppo, J.G. & Rathbone, Robert
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Design of an Interaction Region with Head-On Collisions for the ILC

Description: An interaction region (IR) with head-on collisions is considered as an alternative to the baseline configuration of the International Linear Collider (ILC) which includes two IRs with finite crossing-angles (2 and 20 mrad). Although more challenging for the beam extraction, the head-on scheme is favored by the experiments because it allows a more convenient detector configuration, particularly in the forward region. The optics of the head-on extraction is revisited by separating the e+ and e- b… more
Date: July 12, 2006
Creator: Appleby, R.; U., /Cockcroft Inst. Accel. Sci. Tech. /Manchester; Angal-Kalinin, D.; Jackson, F.; /Daresbury; Alabau-Pons, M . et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Benefits of IEEE-754 features in modern symmetric tridiagonaleigensolvers

Description: Bisection is one of the most common methods used to compute the eigenvalues of symmetric tridiagonal matrices. Bisection relies on the Sturm count: For a given shift a, the number of negative pivots in the factorization T - {sigma}I = LDL{sup T} equals the number of eigenvalues of T that are smaller than a. In IEEE-754 arithmetic, the value oo permits the computation to continue past a zero pivot, producing a correct Sturm count when T is unreduced. Demmel and Li showed that using oo rather tha… more
Date: March 12, 2006
Creator: Marques, Osni; Riedy, Jason E. & Vomel, Christof
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Development and analysis of a compact low-conversion ratio fast burner reactor.

Description: This report explores design options for compact fast burner reactors that can achieve low conversion ratios. Operational characteristics and whole-core reactivity coefficients are generated and contrasted with low conversion ratio designs of previous studies. A compact core point design is then selected and detailed reactivity coefficients are displayed and discussed. The effectiveness of fast spectrum systems for actinide transmutation has been well documented. The key advantage of the fast sp… more
Date: May 12, 2006
Creator: Smith, M. A. & Hill, R. N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Final Hazard Categorization for the Remediation of Six 300-FF-2 Operable Unit Solid Waste Burial Grounds

Description: This report provides the final hazard categorization (FHC) for the remediation of six solid waste disposal sites (referred to as burial grounds) located in the 300-FF-2 Operable Unit (OU) on the Hanford Site. These six sites (618-1, 618-2, 618-3, 618-7, 618-8, and 618-13 Burial Grounds) were determined to have a total radionuclide inventory (WCH 2005a, WCH 2005d, WCH 2005e and WCH 2006b) that exceeds the DOE-STD-1027 Category 3 threshold quantity (DOE 1997) and are the subject of this analysis.… more
Date: December 12, 2006
Creator: Ludowise, J. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

An Exact Solution of Transport in Porous Media with Equilibrium and Kinetic Reactions

Description: This paper presents an analytical solution of reactive transport with equilibrium and kinetic reactions. A benchmark model of A {leftrightarrow} B {leftrightarrow} C {yields} chain reactions is developed for the purpose of verifying numerical computer codes and qualifying mathematical models. A reaction matrix is derived for both the equilibrium and first-order kinetic reactions and further decoupled as a diagonal matrix. Therefore, the partial differential equations (PDEs) coupled by the react… more
Date: April 12, 2006
Creator: Lu, X. & Sun, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen