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Studies of non-proportionality in alkali halide and strontium iodide scintillators using SLYNCI (open access)

Studies of non-proportionality in alkali halide and strontium iodide scintillators using SLYNCI

Recently a collaboration of LLNL and LBNL has constructed a second generation Compton coincidence instrument to study the non-proportionality of scintillators. This device, known as SLYNCI (Scintillator Light-Yield Non-proportionality Characterization Instrument), has can completely characterize a sample with less than 24 hours of running time. Thus, SLYNCI enables a number of systematic studies of scintillators since many samples can be processed in a reasonable length of time. These studies include differences in nonproportionality between different types of scintillators, different members of the same family of scintillators, and impact of different doping levels. The results of such recent studies are presented here, including a study of various alkali halides, and the impact of europium doping level in strontium iodide. Directions of future work area also discussed.
Date: October 14, 2010
Creator: Ahle, Larry; Bizarri, Gregory; Boatner, Lynn; Cherepy, Nerine J.; Choong, Woon-Seng; Moses, William W. et al.
System: The UNT Digital Library
IDENTIFYING IMPURITIES IN SURPLUS NON PIT PLUTONIUM FEEDS FOR MOX OR ALTERNATIVE DISPOSITION (open access)

IDENTIFYING IMPURITIES IN SURPLUS NON PIT PLUTONIUM FEEDS FOR MOX OR ALTERNATIVE DISPOSITION

This report provides a technical basis for estimating the level of corrosion products in materials stored in DOE-STD-3013 containers based on extrapolating available chemical sample results. The primary focus is to estimate the levels of nickel, iron, and chromium impurities in plutonium-bearing materials identified for disposition in the United States Mixed Oxide fuel process.
Date: July 14, 2010
Creator: Allender, J & Moore, E
System: The UNT Digital Library
Interferometric adaptive optics for the National Ignition Facility (open access)

Interferometric adaptive optics for the National Ignition Facility

None
Date: January 14, 2010
Creator: Baker, K.; Homoelle, D.; Stappaerts, E.; Siders, C. & Barty, C.
System: The UNT Digital Library
Precise Predictions for W 4 Jet Production at the Large Hadron Collider (open access)

Precise Predictions for W 4 Jet Production at the Large Hadron Collider

We present the first next-to-leading order QCD results for W + 4-jet production at hadron colliders. Total cross sections, as well as distributions in the jet transverse momenta and in the total transverse energy HT, are provided for the initial LHC energy of {radical}s = 7 TeV. We use a leading-color approximation, known to be accurate to 3% for W production with fewer jets. The virtual matrix elements and the most complicated real-emission matrix elements are handled by the BlackHat library, based on on-shell methods. The remaining parts of the calculation, including the integration over phase space, are performed by the SHERPA package.
Date: September 14, 2010
Creator: Berger, C.F.; /MIT, LNS; Bern, Z.; /UCLA; Dixon, Lance J.; /SLAC, /CERN et al.
System: The UNT Digital Library
Hurricane Intensity, Sea Surface Temperature, and Stochastic Variation (open access)

Hurricane Intensity, Sea Surface Temperature, and Stochastic Variation

None
Date: July 14, 2010
Creator: Bogen, K. T.; Fischer, L. E. & Jones, E. D.
System: The UNT Digital Library
A Benchmark Comparison of Monte Carlo Particle Transport Algorithms for Binary Stochastic Mixtures (open access)

A Benchmark Comparison of Monte Carlo Particle Transport Algorithms for Binary Stochastic Mixtures

None
Date: May 14, 2010
Creator: Brantley, P
System: The UNT Digital Library
COG - Special Features of Interest to Criticality Safety Practitioners (open access)

COG - Special Features of Interest to Criticality Safety Practitioners

COG is a modern, general-purpose, high fidelity, multi-particle transport code developed at the Lawrence Livermore National Laboratory specifically for use in deep penetration (shielding) and criticality safety calculations. This paper describes some features in COG of special interest to criticality safety practitioners.
Date: January 14, 2010
Creator: Buck, R M; Heinrichs, D P; Krass, A W & Lent, E M
System: The UNT Digital Library
Performace of Multi-Probe Corrosion Monitoring Systems at the Hanford Site (open access)

Performace of Multi-Probe Corrosion Monitoring Systems at the Hanford Site

Between 2007 and 2009, several different multi-probe corrosion monitoring systems were designed and installed in high-level nuclear waste tanks at the U.S. Department of Energy's Hanford Site in WaShington State. The probe systems are being monitored to ensure waste tanks operate in regions that minimize localized corrosion (i.e., pitting) and stress corrosion cracking. The corrosion monitoring systems have been installed in wastes with different chemistry types. An ongoing effort during the same time period has generated non-radioactive simulants that are tested in the laboratory to establish baseline corrosion monitoring system performance and characterize data to allow interpretation of readings from the multiple corrosion monitoring systems. Data collection from these monitoring systems has reached the point where the results allow comparison with the laboratory testing. This paper presents analytical results from the corrosion monitoring system development program.
Date: January 14, 2010
Creator: Carothers, K. D.; Boomer, K. D.; Anda, V. S.; Dahl, M. M. & Edgemon, G. L.
System: The UNT Digital Library
Focused ion beam patterned Fe thin films A study by selective area Stokes polarimetry and soft x-Ray microscopy (open access)

Focused ion beam patterned Fe thin films A study by selective area Stokes polarimetry and soft x-Ray microscopy

We demonstrate the potential to modify the magnetic behavior and structural properties of ferromagnetic thin films using focused ion beam 'direct-write' lithography. Patterns inspired by the split-ring resonators often used as components in meta-materials were defined upon 15 nm Fe films using a 30 keV Ga{sup +} focused ion beam at a dose of 2 x 10{sup 16} ions cm{sup -2}. Structural, chemical and magnetic changes to the Fe were studied using transmission soft X-ray microscopy at the ALS, Berkeley CA. X-ray absorption spectra showed a 23% reduction in the thickness of the film in the Ga irradiated areas, but no chemical change to the Fe was evident. X-ray images of the magnetic reversal process show domain wall pinning around the implanted areas, resulting in an overall increase in the coercivity of the film. Transmission electron microscopy showed significant grain growth in the implanted regions.
Date: November 14, 2010
Creator: Cook, P. J.; Shen, T. H.; Grundy, P. J.; Im, M.-Y.; Fischer, P.; Morton, S. A. et al.
System: The UNT Digital Library
CO2 Removal using a Synthetic Analogue of Carbonic Anhydrase (open access)

CO2 Removal using a Synthetic Analogue of Carbonic Anhydrase

Project attempts to develop a synthetic analogue for carbonic anhydrase and incorporate it in a membrane for separation of CO2 from coal power plant flue gas. Conference poster presents result of first 9 months of project progress including concept, basic system architecture and membrane properties target, results of molecular modeling for analogue - CO2 interaction, and next steps of testing analogue resistance to flue gas contaminants.
Date: September 14, 2010
Creator: Cordatos, Harry
System: The UNT Digital Library
System Planning With the Hanford Waste Operations Simulator (open access)

System Planning With the Hanford Waste Operations Simulator

At the U. S. Department of Energy's Hanford Site in southeastern Washington State, 216 million liters (57 million gallons) of nuclear waste is currently stored in aging underground tanks, threatening the Columbia River. The River Protection Project (RPP), a fully integrated system of waste storage, retrieval, treatment, and disposal facilities, is in varying stages of design, construction, operation, and future planning. These facilities face many overlapping technical, regulatory, and financial hurdles to achieve site cleanup and closure. Program execution is ongoing, but completion is currently expected to take approximately 40 more years. Strategic planning for the treatment of Hanford tank waste is by nature a multi-faceted, complex and iterative process. To help manage the planning, a report referred to as the RPP System Plan is prepared to provide a basis for aligning the program scope with the cost and schedule, from upper-tier contracts to individual facility operating plans. The Hanford Tank Waste Operations Simulator (HTWOS), a dynamic flowsheet simulation and mass balance computer model, is used to simulate the current planned RPP mission, evaluate the impacts of changes to the mission, and assist in planning near-term facility operations. Development of additional modeling tools, including an operations research model and a …
Date: January 14, 2010
Creator: Crawford, T. W.; Certa, P. J. & Wells, M. N.
System: The UNT Digital Library
Minimal Doubling and Point Splitting (open access)

Minimal Doubling and Point Splitting

Minimally-doubled chiral fermions have the unusual property of a single local field creating two fermionic species. Spreading the field over hypercubes allows construction of combinations that isolate specific modes. Combining these fields into bilinears produces meson fields of specific quantum numbers. Minimally-doubled fermion actions present the possibility of fast simulations while maintaining one exact chiral symmetry. They do, however, introduce some peculiar aspects. An explicit breaking of hyper-cubic symmetry allows additional counter-terms to appear in the renormalization. While a single field creates two different species, spreading this field over nearby sites allows isolation of specific states and the construction of physical meson operators. Finally, lattice artifacts break isospin and give two of the three pseudoscalar mesons an additional contribution to their mass. Depending on the sign of this mass splitting, one can either have a traditional Goldstone pseudoscalar meson or a parity breaking Aoki-like phase.
Date: June 14, 2010
Creator: Creutz, M.
System: The UNT Digital Library
MEASUREMENT OF TRITIUM DURING VOLOXIDATION OF ZIRCALOY-2 FUEL HULLS (open access)

MEASUREMENT OF TRITIUM DURING VOLOXIDATION OF ZIRCALOY-2 FUEL HULLS

A straightforward method to evaluate the tritium content of Zircaloy-2 cladding hulls via oxidation of the hull and capture of the volatilized tritium in liquids has been demonstrated. Hull samples were heated in air inside a thermogravimetric analyzer (TGA). The TGA was rapidly heated to 1000 C to oxidize the hulls and release absorbed tritium. To capture tritium, the TGA off-gas was bubbled through a series of liquid traps. The concentrations of tritium in bubbler solutions indicated that tritiated water vapor was captured nearly quantitatively. The average tritium content measured in the hulls was 19% of the amount of tritium produced by the fuel, according to ORIGEN2 isotope generation and depletion calculations. Published experimental data show that Zircaloy-2 oxidation follows an Arrhenius model, and that an initial, nonlinear oxidation rate is followed by a faster, linear rate after 'breakaway' of the oxide film. This study demonstrates that the linear oxidation rate of Zircaloy samples at 974 C is faster than predicted by the extrapolation of data from lower temperatures.
Date: October 14, 2010
Creator: Crowder, M.; Laurinat, J. & Stillman, J.
System: The UNT Digital Library
Comparison of Demand Response Performance with an EnergyPlus Model in a Low Energy Campus Building (open access)

Comparison of Demand Response Performance with an EnergyPlus Model in a Low Energy Campus Building

We have studied a low energy building on a campus of the University of California. It has efficient heating, ventilation, and air conditioning (HVAC) systems, consisting of a dual-fan/dual-duct variable air volume (VAV) system. As a major building on the campus, it was included in two demand response (DR) events in the summers of 2008 and 2009. With chilled water supplied by thermal energy storage in the central plant, cooling fans played a critical role during DR events. In this paper, an EnergyPlus model of the building was developed and calibrated. We compared both whole-building and HVAC fan energy consumption with model predictions to understand why demand savings in 2009 were much lower than in 2008. We also used model simulations of the study building to assess pre-cooling, a strategy that has been shown to improve demand saving and thermal comfort in many types of building. This study indicates a properly calibrated EnergyPlus model can reasonably predict demand savings from DR events and can be useful for designing or optimizing DR strategies.
Date: May 14, 2010
Creator: Dudley, Junqiao Han; Black, Doug; Apte, Mike; Piette, Mary Ann & Berkeley, Pam
System: The UNT Digital Library
Solubility of Phenanthrene in Binary Mixtures of C1-C4 Alcohols at 298.2 K (open access)

Solubility of Phenanthrene in Binary Mixtures of C1-C4 Alcohols at 298.2 K

Article on the solubility of phenanthrene in binary mixtures of C1-C4 alcohols at 298.2 K.
Date: January 14, 2010
Creator: Fakhree, Mohammad Amin Abolghassemi; Acree, William E. (William Eugene) & Jouyban, Abolghasem
System: The UNT Digital Library
Heat Pump Water Heaters and American Homes: A Good Fit? (open access)

Heat Pump Water Heaters and American Homes: A Good Fit?

Heat pump water heaters (HPWHs) are over twice as energy-efficient as conventional electric resistance water heaters, with the potential to save substantial amounts of electricity. Drawing on analysis conducted for the U.S. Department of Energy's recently-concluded rulemaking on amended standards for water heaters, this paper evaluates key issues that will determine how well, and to what extent, this technology will fit in American homes. The key issues include: 1) equipment cost of HPWHs; 2) cooling of the indoor environment by HPWHs; 3) size and air flow requirements of HPWHs; 4) performance of HPWH under different climate conditions and varying hot water use patterns; and 5) operating cost savings under different electricity prices and hot water use. The paper presents the results of a life-cycle cost analysis of the adoption of HPWHs in a representative sample of American homes, as well as national impact analysis for different market share scenarios. Assuming equipment costs that would result from high production volume, the results show that HPWHs can be cost effective in all regions for most single family homes, especially when the water heater is not installed in a conditioned space. HPWHs are not cost effective for most manufactured home and multi-family installations, …
Date: May 14, 2010
Creator: Franco, Victor; Lekov, Alex; Meyers, Steve & Letschert, Virginie
System: The UNT Digital Library
Minimizing MPI Resource Contention in Multithreaded Multicore Environments (open access)

Minimizing MPI Resource Contention in Multithreaded Multicore Environments

None
Date: July 14, 2010
Creator: Goodell, D; Balaji, P; Buntinas, D; Dozsa, G; Gropp, W; Kumar, S et al.
System: The UNT Digital Library
Benzene-derived N2-(4-hydroxyphenyl)-deoxyguanosine adduct: UvrABC incision and its conformation in DNA (open access)

Benzene-derived N2-(4-hydroxyphenyl)-deoxyguanosine adduct: UvrABC incision and its conformation in DNA

Benzene, a ubiquitous human carcinogen, forms DNA adducts through its metabolites such as p-benzoquinone (p-BQ) and hydroquinone (HQ). N(2)-(4-Hydroxyphenyl)-2'-deoxyguanosine (N(2)-4-HOPh-dG) is the principal adduct identified in vivo by (32)P-postlabeling in cells or animals treated with p-BQ or HQ. To study its effect on repair specificity and replication fidelity, we recently synthesized defined oligonucleotides containing a site-specific adduct using phosphoramidite chemistry. We here report the repair of this adduct by Escherichia coli UvrABC complex, which performs the initial damage recognition and incision steps in the nucleotide excision repair (NER) pathway. We first showed that the p-BQ-treated plasmid was efficiently cleaved by the complex, indicating the formation of DNA lesions that are substrates for NER. Using a 40-mer substrate, we found that UvrABC incises the DNA strand containing N(2)-4-HOPh-dG in a dose- and time-dependent manner. The specificity of such repair was also compared with that of DNA glycosylases and damage-specific endonucleases of E. coli, both of which were found to have no detectable activity toward N(2)-4-HOPh-dG. To understand why this adduct is specifically recognized and processed by UvrABC, molecular modeling studies were performed. Analysis of molecular dynamics trajectories showed that stable G:C-like hydrogen bonding patterns of all three Watson-Crick hydrogen bonds are …
Date: June 14, 2010
Creator: Hang, Bo; Rodriguez, Ben; Yang, Yanu; Guliaev, Anton B. & Chenna, Ahmed
System: The UNT Digital Library
LLNL's Precision Compton Scattering Light Source (open access)

LLNL's Precision Compton Scattering Light Source

None
Date: September 14, 2010
Creator: Hartemann, F.; Albert, F.; Anderson, S.; Bayramian, A.; Cross, R.; Ebbers, C. et al.
System: The UNT Digital Library
Simple Fully Automated Group Classification on Brain fMRI (open access)

Simple Fully Automated Group Classification on Brain fMRI

We propose a simple, well grounded classification technique which is suited for group classification on brain fMRI data sets that have high dimensionality, small number of subjects, high noise level, high subject variability, imperfect registration and capture subtle cognitive effects. We propose threshold-split region as a new feature selection method and majority voteas the classification technique. Our method does not require a predefined set of regions of interest. We use average acros ssessions, only one feature perexperimental condition, feature independence assumption, and simple classifiers. The seeming counter-intuitive approach of using a simple design is supported by signal processing and statistical theory. Experimental results in two block design data sets that capture brain function under distinct monetary rewards for cocaine addicted and control subjects, show that our method exhibits increased generalization accuracy compared to commonly used feature selection and classification techniques.
Date: April 14, 2010
Creator: Honorio, J.; Goldstein, R.; Honorio, J.; Samaras, D.; Tomasi, D. & Goldstein, R.Z.
System: The UNT Digital Library
Hybrid Parallelism for Volume Rendering on Large, Multi-core Systems (open access)

Hybrid Parallelism for Volume Rendering on Large, Multi-core Systems

This work studies the performance and scalability characteristics of"hybrid" parallel programming and execution as applied to raycasting volume rendering -- a staple visualization algorithm -- on a large, multi-core platform. Historically, the Message Passing Interface (MPI) has become the de-facto standard for parallel programming and execution on modern parallel systems. As the computing industry trends towards multi-core processors, with four- and six-core chips common today and 128-core chips coming soon, we wish to better understand how algorithmic and parallel programming choices impact performance and scalability on large, distributed-memory multi-core systems. Our findings indicate that the hybrid-parallel implementation, at levels of concurrency ranging from 1,728 to 216,000, performs better, uses a smaller absolute memory footprint, and consumes less communication bandwidth than the traditional, MPI-only implementation.
Date: June 14, 2010
Creator: Howison, Mark; Bethel, E. Wes & Childs, Hank
System: The UNT Digital Library
Verification for Portability, Scalability, and Grokkability (open access)

Verification for Portability, Scalability, and Grokkability

None
Date: July 14, 2010
Creator: Humphrey, Alan; Derrick, Christopher; Tibbitts, Beth; Vo, Anh; Vakkalanka, Sarvani; Gopalakrishnan, Ganesh et al.
System: The UNT Digital Library
THE SENSITIVITY OF CARBON STEELS' SUSCEPTIBILITY TO LOCALIZED CORROSION TO THE PH OF NITRATE BASED NUCLEAR WASTES (open access)

THE SENSITIVITY OF CARBON STEELS' SUSCEPTIBILITY TO LOCALIZED CORROSION TO THE PH OF NITRATE BASED NUCLEAR WASTES

The Hanford tank reservation contains approximately 50 million gallons of liquid legacy radioactive waste from cold war weapons production, which is stored in 177 underground storage tanks. The tanks will be in use until waste processing operations are completed. The wastes tend to be high pH (over 10) and nitrate based. Under these alkaline conditions carbon steels tend to be passive and undergo relatively slow uniform corrosion. However, the presence of nitrate and other aggressive species, can lead to pitting and stress corrosion cracking. This work is a continuation of previous work that investigated the propensity of steels to suffer pitting and stress corrosion cracking in various waste simulants. The focus of this work is an investigation of the sensitivity of the steels' pitting and stress corrosion cracking susceptibility tosimulant pH. Previous work demonstrated that wastes that are high in aggressive nitrate and low in inhibitory nitrite are susceptible to localized corrosion. However, the previous work involved wastes with pH 12 or higher. The current work involves wastes with lower pH of 10 or 11. It is expected that at these lower pHs that a higher nitrite-to-nitrate ratio will be necessary to ensure tank integrity. This experimental work involved both …
Date: January 14, 2010
Creator: KD, BOOMER
System: The UNT Digital Library
TANK OPERATIONS CONTRACT CONSTRUCTION MANAGEMENT METHODOLOGY UTILIZING THE AGENCY METHOD OF CONSTRUCTION MANAGEMENT TO SAFELY AND EFFECTIVELY COMPLETE NUCLEAR CONSTRUCTION WORK (open access)

TANK OPERATIONS CONTRACT CONSTRUCTION MANAGEMENT METHODOLOGY UTILIZING THE AGENCY METHOD OF CONSTRUCTION MANAGEMENT TO SAFELY AND EFFECTIVELY COMPLETE NUCLEAR CONSTRUCTION WORK

Washington River Protection Solutions, LLC (WRPS) has faced significant project management challenges in managing Davis-Bacon construction work that meets contractually required small business goals. The unique challenge is to provide contracting opportunities to multiple small business construction subcontractors while performing high hazard work in a safe and productive manner. Previous to the Washington River Protection Solutions, LLC contract, Construction work at the Hanford Tank Farms was contracted to large companies, while current Department of Energy (DOE) Contracts typically emphasize small business awards. As an integral part of Nuclear Project Management at Hanford Tank Farms, construction involves removal of old equipment and structures and installation of new infrastructure to support waste retrieval and waste feed delivery to the Waste Treatment Plant. Utilizing the optimum construction approach ensures that the contractors responsible for this work are successful in meeting safety, quality, cost and schedule objectives while working in a very hazardous environment. This paper describes the successful transition from a traditional project delivery method that utilized a large business general contractor and subcontractors to a new project construction management model that is more oriented to small businesses. Construction has selected the Agency Construction Management Method. This method was implemented in the first …
Date: January 14, 2010
Creator: KF, LESO; HM, HAMILTON; M, FARNER & T, HEATH
System: The UNT Digital Library