Month

ORNL Cray X1 Evaluation Status Report (open access)

ORNL Cray X1 Evaluation Status Report

On August 15, 2002 the Department of Energy (DOE) selected the Center for Computational Sciences (CCS) at Oak Ridge National Laboratory (ORNL) to deploy a new scalable vector supercomputer architecture for solving important scientific problems in climate, fusion, biology, nanoscale materials and astrophysics. ''This program is one of the first steps in an initiative designed to provide U.S. scientists with the computational power that is essential to 21st century scientific leadership,'' said Dr. Raymond L. Orbach, director of the department's Office of Science. In FY03, CCS procured a 256-processor Cray X1 to evaluate the processors, memory subsystem, scalability of the architecture, software environment and to predict the expected sustained performance on key DOE applications codes. The results of the micro-benchmarks and kernel bench marks show the architecture of the Cray X1 to be exceptionally fast for most operations. The best results are shown on large problems, where it is not possible to fit the entire problem into the cache of the processors. These large problems are exactly the types of problems that are important for the DOE and ultra-scale simulation. Application performance is found to be markedly improved by this architecture: - Large-scale simulations of high-temperature superconductors run 25 times …
Date: May 1, 2004
Creator: Agarwal, P. K.; Alexander, R. A.; Apra, E.; Balay, S.; Bland, A. S.; Colgan, J. et al.
Object Type: Article
System: The UNT Digital Library
Development of a Novel Catalyst for NO Decomposition (open access)

Development of a Novel Catalyst for NO Decomposition

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation …
Date: May 1, 2004
Creator: Akyurtlu, Ates & Akyurtlu, Jale F.
Object Type: Report
System: The UNT Digital Library
Smart Screening System (S3) In Taconite Processing (open access)

Smart Screening System (S3) In Taconite Processing

The conventional vibrating machines used in processing plants have had undesirable high noise and vibration levels. They also have had unsatisfactorily low screening efficiency, high energy consumption, high maintenance cost, low productivity, and poor worker safety. These conventional vibrating machines have been used in most every processing plant. Most of the current material separation technology uses heavy and inefficient electric motors with an unbalance rotating mass to generate the shaking. In addition to being excessively noisy, inefficient, and high-maintenance, these vibrating machines are often the bottleneck in the entire process. Furthermore, these motors, along with the vibrating machines and supporting structure, shake other machines and structures in the vicinity. The latter increases maintenance costs while reducing worker health and safety. The conventional vibrating fine screens at taconite processing plants have had the same problems as those listed above. This has resulted in lower screening efficiency, higher energy and maintenance cost, and lower productivity and workers safety concerns. The focus of this work is on the design of a high performance screening machine suitable for taconite processing plants. SmartScreens{trademark} technology uses miniaturized motors, based on smart materials, to generate the shaking. The underlying technologies are Energy Flow Control{trademark} and Vibration Control …
Date: May 1, 2004
Creator: Allaei, Daryoush; Mohammed, Asim Syed & Tarnowski, David
Object Type: Report
System: The UNT Digital Library
Research in Hydrogen Passivation of Defects and Impurities in Silicon: Final Subcontract Report, 2 May 2000--2 July 2003 (open access)

Research in Hydrogen Passivation of Defects and Impurities in Silicon: Final Subcontract Report, 2 May 2000--2 July 2003

Our work consists of hydrogenating silicon (Si) samples by different methods such as low-energy implantation, electron cyclotron resonance (ECR) plasma, and thermal diffusion. The samples will be provided through NREL. The experimental work carried out at Penn State involves the study of hydrogen interaction with defects, trapping, migration, and formation of complexes. The principal vehicle for the latter study will be ion implantation, and the intent is to understand mechanisms of defect passivation and activation by hydrogen. The theoretical studies will consist of the calculation of the structure and parameters related to hydrogen diffusion and interactions of hydrogen with transition metal impurities in silicon. Experimental studies will involve measurements of hydrogen and hydrogen-impurity complexes, and diffusion properties of various species of hydrogen in Si. The experimental work at Penn State includes introduction of hydrogen in a variety of photovoltaic Si by ECR plasma, low-energy ion implantation, and thermal diffusion. The specific tasks will be the evaluation of hydrogen interaction with defects engineered by ion implantation; defect passivation, activation, and migration in hydrogenated Si under thermal anneal; and electrical activity of hydrogen-impurity complexes. Electrical characterization will entail I-V and C-V measurements, spreading resistance, and deep-level transient spectroscopy.
Date: May 1, 2004
Creator: Ashok, S.
Object Type: Report
System: The UNT Digital Library
The CMS forward calorimeter prototype design studies and Omega(c)0 search at E781 experiment at Fermilab (open access)

The CMS forward calorimeter prototype design studies and Omega(c)0 search at E781 experiment at Fermilab

In the fit part, the Compact Muon Solenoid (CMS) forward calorimeter design studies are presented. The forward calorimeter consists of quartz fibers embedded in a steel absorber. Radiation damage studies of the quartz fiber and the absorber as well as the results of the first pre-production prototype PPP-I are presented. In the second part, the {Omega}{sub c}{sup 0}search studies at the SELEX (E781) experiment at FermiLab are presented. 107 {+-} 22 {Omega}{sub c}{sup 0} events are observed in three decay modes. The relative branching ratio ({Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup -}{pi}{sup +}{pi}{sup +})/{Beta}({Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +}) is measured as 2.00 {+-} 0.45(stat) {+-} 0.32(sys).
Date: May 1, 2004
Creator: Ayan, Ahmet Sedat
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Impact of Uranium Levels ON Sludge Batch 2 Simulant Processing (open access)

Impact of Uranium Levels ON Sludge Batch 2 Simulant Processing

The Defense Waste Processing Facility began processing Sludge Batch 2 (SB2) in December of 2001. Since the introduction of the first SRAT batch of SB2, processing issues have been observed in the Sludge Receipt and Adjustment Tank, Slurry Mix Evaporator Melter Feed Tank and the melter. These issues coincided with the start of Batch 209, the first full batch from SB2a5. The issues involved the ability to transfer process slurries and feed the melter, difficulty maintaining heat transfer in the SME, and degradation of the operation of the melter. One of the primary differences between Sludge Batch 2 and the previous Sludge Batches is the increased content of uranium. The Savannah River National Laboratory was requested by DWPF via Technical Task Request HLW/DWPF TTR-02-0035 to determine if the processing issues are related to the elevated levels of uranium in SB21. The work reported here is intended to address only a portion of TTR-0035, specifically the impact of uranium on Sludge Batch 2. This work is governed by a Task Technical and Quality Assurance Plan 2 and an Analytical Study Plan 3. SRNL conducted small-scale tests designed to determine the effect of different levels of uranium on sludge processing at the …
Date: May 1, 2004
Creator: BANNOCHIE, CHRISTOPHERJ.
Object Type: Report
System: The UNT Digital Library
How plant functional-type, weather, seasonal drought and soil physical properties alter water and energy fluxes of an oak-grass savanna and an annual grassland. (open access)

How plant functional-type, weather, seasonal drought and soil physical properties alter water and energy fluxes of an oak-grass savanna and an annual grassland.

Savannas and open grasslands often co-exist in semi-arid regions. Questions that remain unanswered and are of interest to biometeorologists include: how do these contrasting landscapes affect the exchanges of energy on seasonal and annual time scales; and, do biophysical constraints imposed by water supply and water demand affect whether the land is occupied by open grasslands or savanna? To address these questions, and others, we examine how a number of abiotic, biotic and edaphic factors modulate water and energy flux densities over an oak-grass savanna and an annual grassland that coexist in the same climate but on soils with different hydraulic properties. The net radiation balance was greater over the oak woodland than the grassland, despite the fact that both canopies received similar sums of incoming short and long wave radiation. The lower albedo and lower radiative surface temperature of the transpiring woodland caused it to intercept and retain more long and shortwave energy over the course of the year, and particularly during the summer dry period. The partitioning of available energy into sensible and latent heat exchanged over the two canopies differed markedly. The annual sum of sensible heat exchange over the woodland was 40% greater than that over …
Date: May 1, 2004
Creator: Baldocchi, DD, Xu L, Kiang N.
Object Type: Article
System: The UNT Digital Library
Oxygen Transport Ceramic Membranes (open access)

Oxygen Transport Ceramic Membranes

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C in N{sub 2}. Space group of R3c was found to result in a better refinement and is used in this study. The difference for crystal structure, lattice parameters and local crystal chemistry for LSFT nearly unchanged when gas environment switched from air to N{sub 2}. Stable crack growth studies on Dense OTM bars provided by Praxair were done at room temperature in air. A bridge-compression fixture was fabricated to achieve stable pre-cracks from Vickers indents. Post fracture evaluation indicated stable crack growth from the indent and a regime of fast fracture. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture …
Date: May 1, 2004
Creator: Bandopadhyay, S.; Nagabhushana, N.; Zhou, X. -D.; Cai, Q.; Yang, J.; Yelon, W. B. et al.
Object Type: Report
System: The UNT Digital Library
Oxygen Transport Ceramic Membranes (open access)

Oxygen Transport Ceramic Membranes

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C. It was found that space group of R3c yielded a better refinement than a cubic structure of Pm3m. Oxygen occupancy was nearly 3 in the region from room temperature to 700 C, above which the occupancy decreased due to oxygen loss. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. The X-Ray data and fracture mechanisms points to non-equilibrium decomposition of the LSFCO OTM membrane. The non-equilibrium conditions could probably be due to the nature of the applied stress field (stressing rates) and leads to transition in crystal structures and increased kinetics of decomposition. The formations of a Brownmillerite or Sr2Fe2O5 type …
Date: May 1, 2004
Creator: Bandopadhyay, S.; Nagabhushana, N.; Zhou, X. -D.; Cai, Q.; Yang, J.; Yelon, W. B. et al.
Object Type: Report
System: The UNT Digital Library
Sludge Batch 2/3 Blend SRAT Cycle in the SRNL Shielded Cells (open access)

Sludge Batch 2/3 Blend SRAT Cycle in the SRNL Shielded Cells

The work conducted for this report was done to determine whether any processing problems could be anticipated with the blended material from Tank 40 and 51. The purpose of this report is to document the results of a SB2/3 blend Sludge Receipt Adjustment Tank (SRAT) cycle performed at the Savannah River National Laboratory (SRNL) Shielded Cells Facility (SCF). The following conclusions are drawn from this work: the SB2/3 blend supernate has a surface tension significantly higher than SB2 simulants and close to that of water; SB2/3 blend rheology is slightly more viscous and visually more cohesive than a SB3 sample alone; SRAT cycle processing of a SB2/3 blend was accomplished with no significant issues. Nitrite was destroyed at 140 per cent of acid stoichiometry. Hydrogen generation was well within DWPF limits. Nitrous oxide generation was well within DWPF limits. Considerable soluble uranium was measured in the SRAT product, likely as a result of the final pH of the SRAT product. SB2/3 blend SRAT product is less viscous than the starting feed with both the consistency and yield stress below the recommended DWPF operating region. The demonstration of simulated DWPF SRAT cycle processing of a radioactive SB2/3 blend based upon the …
Date: May 1, 2004
Creator: Bannochie, Christopher J.
Object Type: Report
System: The UNT Digital Library
Sodium-bearing Waste Treatment Technology Evaluation Report (open access)

Sodium-bearing Waste Treatment Technology Evaluation Report

Sodium-bearing waste (SBW) disposition is one of the U.S. Department of Energy (DOE) Idaho Operation Office’s (NE-ID) and State of Idaho’s top priorities at the Idaho National Engineering and Environmental Laboratory (INEEL). The INEEL has been working over the past several years to identify a treatment technology that meets NE-ID and regulatory treatment requirements, including consideration of stakeholder input. Many studies, including the High-Level Waste and Facilities Disposition Environmental Impact Statement (EIS), have resulted in the identification of five treatment alternatives that form a short list of perhaps the most appropriate technologies for the DOE to select from. The alternatives are (a) calcination with maximum achievable control technology (MACT) upgrade, (b) steam reforming, (c) cesium ion exchange (CsIX) with immobilization, (d) direct evaporation, and (e) vitrification. Each alternative has undergone some degree of applied technical development and preliminary process design over the past four years. This report presents a summary of the applied technology and process design activities performed through February 2004. The SBW issue and the five alternatives are described in Sections 2 and 3, respectively. Details of preliminary process design activities for three of the alternatives (steam reforming, CsIX, and direct evaporation) are presented in three appendices. A …
Date: May 1, 2004
Creator: Barnes, Charles M.; Olson, Arlin L. & Taylor, Dean D.
Object Type: Report
System: The UNT Digital Library
Surrogate/spent fuel sabotage : aerosol ratio test program and Phase 2 test results. (open access)

Surrogate/spent fuel sabotage : aerosol ratio test program and Phase 2 test results.

A multinational test program is in progress to quantify the aerosol particulates produced when a high energy density device, HEDD, impacts surrogate material and actual spent fuel test rodlets. This program provides needed data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments; the program also provides significant political benefits in international cooperation. We are quantifying the spent fuel ratio, SFR, the ratio of the aerosol particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials, measured under closely matched test conditions. In addition, we are measuring the amounts, nuclide content, size distribution of the released aerosol materials, and enhanced sorption of volatile fission product nuclides onto specific aerosol particle size fractions. These data are crucial for predicting radiological impacts. This document includes a thorough description of the test program, including the current, detailed test plan, concept and design, plus a description of all test components, and requirements for future components and related nuclear facility needs. It also serves as a program status report as of the end of FY 2003. All available test results, observations, and analyses - primarily for surrogate material Phase …
Date: May 1, 2004
Creator: Borek, Theodore Thaddeus, III; Thompson, N. Slater; Sorenson, Ken Bryce; Hibbs, R. S.; Nolte, Oliver; Molecke, Martin Alan et al.
Object Type: Report
System: The UNT Digital Library
Evaluation of Retro Commissioning Persistence in Large Commercial Buildings (open access)

Evaluation of Retro Commissioning Persistence in Large Commercial Buildings

Commercial Building Retrocommissioning activity has increased in recent years. This paper discusses LBNL's recently conducted study of 8 participants in the Sacramento Municipal Utility District Retrocommissioning program. We evaluated the persistence of energy savings and measure implementation, in an effort to identify and understand factors that can improve the longevity of retrocommissioning benefits. The LBNL analysis included a whole-building and measure status analysis, incorporating elements of previous work by Texas A&M University and Portland Energy Conservation Inc. Included in the energy analysis were whole building calculated energy savings and consideration of effects from the 2001 energy crisis. The measure persistence analysis examined each recommended measure and it's current operational status. Results showed a 59% implementation rate of recommended measures. Some process findings were: (1) Building engineers will tweak a measure that didn't work, instead of reverting to the pre-retrocommissioning settings; (2) A majority of the implementation costs were absorbed into regular operation and maintenance budgets; (3) The most frequently reported down side was the large time demands on the building engineering staff. However, all respondents thought it was worth the price; (4) All the sites said that retrocommissioning is beneficial to their operations, due to ongoing training and continuous improvement …
Date: May 1, 2004
Creator: Bourassa, Norman J.; Piette, Mary Ann & Motegi, Naoya
Object Type: Article
System: The UNT Digital Library
Wettability and Prediction of Oil Recovery From Reservoirs Developed With Modern Drilling and Completion Fluids (open access)

Wettability and Prediction of Oil Recovery From Reservoirs Developed With Modern Drilling and Completion Fluids

We report on progress in three areas. In part one, the wetting effects of synthetic base oils are reported. Part two reports progress in understanding the effects of surfactants of known chemical structures, and part three integrates the results from surface and core tests that show the wetting effects of commercial surfactant products used in synthetic and traditional oil-based drilling fluids. An important difference between synthetic and traditional oil-based muds (SBM and OBM, respectively) is the elimination of aromatics from the base oil to meet environmental regulations. The base oils used include dearomatized mineral oils, linear alpha-olefins, internal olefins, and esters. We show in part one that all of these materials except the esters can, at sufficiently high concentrations, destabilize asphaltenes. The effects of asphaltenes on wetting are in part related to their stability. Although asphaltenes have some tendency to adsorb on solid surfaces from a good solvent, that tendency can be much increased near the onset of asphaltene instability. Tests in Berea sandstone cores demonstrate wetting alteration toward less water-wet conditions that occurs when a crude oil is displaced by paraffinic and olefinic SBM base oils, whereas exposure to the ester products has little effect on wetting properties of …
Date: May 1, 2004
Creator: Buckley, Jill S. & Morrow, Norman R.
Object Type: Report
System: The UNT Digital Library
Analytical investigation of AlCl[3]/SO[2]Cl[2] catholyte materials for secondary fuze reserve batteries. (open access)

Analytical investigation of AlCl[3]/SO[2]Cl[2] catholyte materials for secondary fuze reserve batteries.

Exploration of the fundamental chemical behavior of the AlCl{sub 3}/SO{sub 2}Cl{sub 2} catholyte system for the ARDEC Self-Destruct Fuze Reserve Battery Project under accelerated aging conditions was completed using a variety of analytical tools. Four different molecular species were identified in this solution, three of which are major. The relative concentrations of the molecular species formed were found to depend on aging time, initial concentrations, and storage temperature, with each variable affecting the kinetics and thermodynamics of this complex reaction system. We also evaluated the effect of water on the system, and determined that it does not play a role in dictating the observed molecular species present in solution. The first Al-containing species formed was identified as the dimer [Al({mu}-Cl)Cl{sub 2}]{sub 2}, and was found to be in equilibrium with the monomer, AlCl{sub 3}. The second species formed in the reaction scheme was identified by single crystal X-ray diffraction studies as [Cl{sub 2}Al({mu}-O{sub 2}SCl)]{sub 2} (I), a scrambled AlCl{sub 3}{center_dot}SO{sub 2} adduct. The SO{sub 2}(g) present, as well as CL{sub 2}(g), was formed through decomposition of SO{sub 2}CL{sub 2}. The SO{sub 2}(g) generated was readily consumed by AlCl{sub 3} to form the adduct 1 which was experimentally verified when 1 …
Date: May 1, 2004
Creator: Butler, Paul Charles; Rodriguez, Mark Andrew; Segall, Judith M.; Malizia, Louis A., Jr.; Cherry, Brian Ray; Andrews, Nicholas L. et al.
Object Type: Report
System: The UNT Digital Library
Transforming the Market for Sustainable Design: Effective Public Policies and Strategies; Preprint (open access)

Transforming the Market for Sustainable Design: Effective Public Policies and Strategies; Preprint

The federal government strives to lead by example in energy and resource management and architectural design. This paper explores how public agencies are supporting that goal by using sustainable practices in the design and operation of their buildings. It presents some elements to consider in establishing a policy for sustainable design and a system for implementing that policy, including some of the most difficult implementation issues agencies have to face. The paper also highlights some of the strengths and weaknesses of federal, state, and local policies and practices governing the design of public buildings; two case studies provide examples. Different approaches are included to help agencies evaluate their effectiveness at various levels of government. And recommendations are made for agencies and others who are committed to sustainable design in both new construction and major renovations.
Date: May 1, 2004
Creator: Carlisle, N.; Glickman, J.; Brown, M.; Foster, M.; Bennett, A. K. & Sandler, K.
Object Type: Article
System: The UNT Digital Library
Investigation of oil injection into brine for the Strategic Petroleum Reserve : hydrodynamics and mixing experiments with SPR liquids. (open access)

Investigation of oil injection into brine for the Strategic Petroleum Reserve : hydrodynamics and mixing experiments with SPR liquids.

An experimental program was conducted to study a proposed approach for oil reintroduction in the Strategic Petroleum Reserve (SPR). The goal was to assess whether useful oil is rendered unusable through formation of a stable oil-brine emulsion during reintroduction of degassed oil into the brine layer in storage caverns. An earlier report (O'Hern et al., 2003) documented the first stage of the program, in which simulant liquids were used to characterize the buoyant plume that is produced when a jet of crude oil is injected downward into brine. This report documents the final two test series. In the first, the plume hydrodynamics experiments were completed using SPR oil, brine, and sludge. In the second, oil reinjection into brine was run for approximately 6 hours, and sampling of oil, sludge, and brine was performed over the next 3 months so that the long-term effects of oil-sludge mixing could be assessed. For both series, the experiment consisted of a large transparent vessel that is a scale model of the proposed oil-injection process at the SPR. For the plume hydrodynamics experiments, an oil layer was floated on top of a brine layer in the first test series and on top of a sludge …
Date: May 1, 2004
Creator: Castaneda, Jaime N.; Cote, Raymond O.; Torczynski, John R. & O'Hern, Timothy John
Object Type: Report
System: The UNT Digital Library
Experiences in the Performance Analysis and Optimization of a Deterministic Radiation Transport Code on the Cray SV1 (open access)

Experiences in the Performance Analysis and Optimization of a Deterministic Radiation Transport Code on the Cray SV1

The Attila radiation transport code, which solves the Boltzmann neutron transport equation on three-dimensional unstructured tetrahedral meshes, was ported to a Cray SV1. Cray's performance analysis tools pointed to two subroutines that together accounted for 80%-90% of the total CPU time. Source code modifications were performed to enable vectorization of the most significant loops, to correct unfavorable strides through memory, and to replace a conjugate gradient solver subroutine with a call to the Cray Scientific Library. These optimizations resulted in a speedup of 7.79 for the INEEL's largest ATR model. Parallel scalability of the OpenMP version of the code is also discussed, and timing results are given for other non-vector platforms.
Date: May 1, 2004
Creator: Cebull, Peter
Object Type: Article
System: The UNT Digital Library
Hardening Neutron Spectrum for Advanced Actinides Transmutation Experiments in the ATR (open access)

Hardening Neutron Spectrum for Advanced Actinides Transmutation Experiments in the ATR

The most effective method for transmuting long-lived isotopes contained in spent nuclear fuel into shorter-lived fission products is in a fast neutron spectrum reactor. In the absence of a fast rest reactor in the United States, initial irradiation testing of candidate fuels can be performed in a thermal test reactor that has been modified to produce a test region with a hardened neutron spectrum. Such a test facility, with a spectrum similar but somewhat softer than that of the liquid-metal fast breeder reactor (LMFBR), has been constructed in the INEEL's Advanced Test Reactor (ATR). The radial fission power distribution of the actinide fuel pin, which is an important parameter in fission gas released modelling, needs to be accurately predicted and the hardened neturon spectrum in the ATR and the LMFBR fast neutron spectrum is compared. The comparison analyses in this study are peformed using MCWO, a well-developed tool that couples the Monte Carlo transport code MCNP with the isotope depletion and build-up code ORIGEN-2. MCWO analysis yields time-dependent and neutron-spectrum-dependent minor actinide and Pu concentrations and detailed radial fission power profile calculations for a typical fast reactor (LMFBR) neutron spectrum and the hardened neturon spectrum test region in the ATR. …
Date: May 1, 2004
Creator: Chang, G. S. & Ambrosek, R. G.
Object Type: Article
System: The UNT Digital Library
Final report. (This is a conference support, no publications were delivered) (open access)

Final report. (This is a conference support, no publications were delivered)

The Marine Biotechnology Conference held in Chiba, Japan (September 17-21, 2003) was a very successful meeting. Approximately 700 participants from 32 different countries attended this meeting. The proceedings of MBC2003 will be published in a special edition of the journal Marine Biotechnology. Three PIs, Drs. Feng Chen, Russell Hill, and Yonathan Zohar from the Center of Marine Biotechnology led effort to raise a total of $38,000 from NSF, DOE, Maryland Sea Grant, and Martek BioScience Corp to assist 28 U.S. scientists from various research institutions to participate this conference. Among the 28 awardees, 14 are graduate students and postdocs, and five are female scientists. All the awardees gave either oral or poster presentations at the conference. Each graduate student and junior scientist received $1,375 (the maximum amount) in support towards travel to this conference, and each senior scientist (including tenure-track assistant professor) received $655 (the maximum amount). Specifically, eight scientists (3 seniors and 5 juniors) were supported by the DOE travel award (see attached table). A Grants Specialist at the Center of Marine Biotechnology, Mrs. Nanci Henningsen at COMB took care of all the reimbursements, which were completed on January 16, 2004. The availability of travel fund was advertised on …
Date: May 1, 2004
Creator: Chen, F.; Hill, R. & Zohar, Y.
Object Type: Report
System: The UNT Digital Library
Neutrino oscillations in the MINOS experiment and electron identification in the calibration detector (open access)

Neutrino oscillations in the MINOS experiment and electron identification in the calibration detector

None
Date: May 1, 2004
Creator: Choudalakis, Georgios & U., /Athens
Object Type: Report
System: The UNT Digital Library
Interactive Methods for Exploring Particle Simulation Data (open access)

Interactive Methods for Exploring Particle Simulation Data

In this work, we visualize high-dimensional particle simulation data using a suite of scatter plot-based visualizations coupled with interactive selection tools. We use traditional 2D and 3D projection scatter plots as well as a novel oriented disk rendering style to convey various information about the data. Interactive selection tools allow physicists to manually classify ''interesting'' sets of particles that are highlighted across multiple, linked views of the data. The power of our application is the ability to correspond new visual representations of the simulation data with traditional, well understood visualizations. This approach supports the interactive exploration of the high-dimensional space while promoting discovery of new particle behavior.
Date: May 1, 2004
Creator: Co, Christopher S.; Friedman, Alex; Grote, David P.; Vay, Jean-Luc; Bethel, E. Wes & Joy, Kenneth I.
Object Type: Article
System: The UNT Digital Library
Search for first generation leptoquarks in electron + neutrino + dijet channel (open access)

Search for first generation leptoquarks in electron + neutrino + dijet channel

None
Date: May 1, 2004
Creator: Cothenet, Alexis
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Helium nano-bubble evolution in aging metal tritides. (open access)

Helium nano-bubble evolution in aging metal tritides.

A continuum-scale, evolutionary model of helium (He) nano-bubble nucleation, growth and He release for aging bulk metal tritides is presented which accounts for major features of the experimental database. Bubble nucleation, modeled as self-trapping of interstitially diffusing He atoms, is found to occur during the first few days following tritium introduction into the metal and is sensitive to the He diffusivity and pairing energy. An effective helium diffusivity of 0.3 x 10{sup -16} cm{sup 2}/s at 300 K is required to generate the average bubble density of 5x 1017 bubbles/cm3 observed by transmission electron microscopy (TEM). Early bubble growth by dislocation loop punching with a l/radius bubble pressure dependence produces good agreement with He atomic volumes and bubble pressures determined from swelling data, nuclear magnetic resonance (NMR) measurements, and hydride pressure-composition-temperature (PCT) shifts. The model predicts that later in life neighboring bubble interactions may first lower the loop punching pressure through cooperative stress effects, then raise the pressure by partial blocking of loops. It also accounts for the shape of the bubble spacing distribution obtained from NMR data. This distribution is found to remain fixed with age, justifying the separation of nucleation and growth phases, providing a sensitive test of …
Date: May 1, 2004
Creator: Cowgill, Donald F.
Object Type: Report
System: The UNT Digital Library