RESEARCH PLAN FOR SPIN PHYSICS AT RHIC. (open access)

RESEARCH PLAN FOR SPIN PHYSICS AT RHIC.

In this report we present the research plan for the RHIC spin program. The report covers (1) the science of the RHIC spin program in a world-wide context; (2) the collider performance requirements for the RHIC spin program; (3) the detector upgrades required, including timelines; (4) time evolution of the spin program.
Date: February 1, 2005
Creator: AIDALA, C.; BUNCE, G. & AL., ET
Object Type: Report
System: The UNT Digital Library
Measurement of inclusive differential cross sections for Upsilon(1S) production in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Measurement of inclusive differential cross sections for Upsilon(1S) production in p anti-p collisions at s**(1/2) = 1.96-TeV

The authors present measurements of the inclusive production cross sections of the {Upsilon}(1S) bottomonium state in p{bar p} collisions at {radical}s = 1.96 TeV. Using the {Upsilon}(1S) {yields} {mu}{sup +}{mu}{sup -} decay mode for a data sample of 159 {+-} 10 pb{sup -1} collected by the D0 detector at the Fermilab Tevatron collider, they determine the differential cross sections as a function of the {Upsilon}(1S) transverse momentum for three ranges of the {Upsilon}(1S) rapidity: 0 < |y{sup {Upsilon}}| {le} 0.6, 0.6 < |y{sup {Upsilon}}| {le} 1.2, and 1.2 < |y{sup {Upsilon}}| {le} 1.8.
Date: February 1, 2005
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library
Study of Z gamma events and limits on anomalous Z Z gamma and Z gamma gamma couplings in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Study of Z gamma events and limits on anomalous Z Z gamma and Z gamma gamma couplings in p anti-p collisions at s**(1/2) = 1.96-TeV

The authors present a measurement of the Z{gamma} production cross section and limits on anomalous ZZ{gamma} and Z{gamma}{gamma} couplings for form-factor scales of {Lambda} = 750 and 1000 GeV. The measurement is based on 138 (152) candidate events in the ee{gamma} ({mu}{mu}{gamma}) final state using 320 (290) pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are |h{sub 10,30}{sup Z}| < 0.23, |h{sub 20,40}{sup Z}| < 0.020, |h{sub 10,30}{gamma}| < 0.23, and |h{sub 20,40}{gamma}| < 0.019 for {Lambda} = 1000 GeV.
Date: February 1, 2005
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library
Improved Performance in CuInSe2 and Surface-Modified CuGaSe2 Solar Cells (open access)

Improved Performance in CuInSe2 and Surface-Modified CuGaSe2 Solar Cells

In this paper, we present an update and review on the progress made in the development of low-bandgap CuInSe2 (CIS) and wide-bandgap CuGaSe2 (CGS) solar cells. Our research project is a primarily concerned with the optimization of the bottom and top cells of the tandem solar cell. This past year, we established new record total-area efficiencies of 15.0% and 10.2% for CIS and surface-modified CGS solar cells, respectively. These achievements were possible by modifying the growth process for CIS and CGS absorbers. We attempt to modify the surface region of the CGS absorber to be CIGS-like in composition. We also have designed a mechanical-stacked tandem solar cell where the 15% CIS cell serves as the bottom cell. The NREL-confirmed total-area efficiency for this tandem device is 15.31%.
Date: February 1, 2005
Creator: AbuShama, J.; Noufi, R.; Johnston, S.; Ward, S. & Wu, X.
Object Type: Article
System: The UNT Digital Library
Measurement of the moments of the hadronic invariant mass distribution in semileptonic B decays (open access)

Measurement of the moments of the hadronic invariant mass distribution in semileptonic B decays

None
Date: February 1, 2005
Creator: Acosta, D.; Adelman, J.; Affolder, Anthony A.; Akimoto, T.; Albrow, M. G.; Ambrose, D. et al.
Object Type: Article
System: The UNT Digital Library
Performance and Reliability of a 1-kW Amorphous Silicon Photovoltaic Roofing System (open access)

Performance and Reliability of a 1-kW Amorphous Silicon Photovoltaic Roofing System

The National Renewable Energy Laboratory (NREL) has been monitoring the performance of a 1- kWAC United Solar Systems Corporation (USSC) roofing system over the 6-year period from October 1998 to September 2004. This paper will investigate the performance and reliability of this system. The annual degradation and seasonal fluctuation of the system's power output are calculated using the PVUSA power rating regression model. The system performance is also examined using the additional performance parameters of yield, reference yield, and performance ratio, which allows for a somewhat less complicated data collection and analysis. The data indicate that the system has exhibited stable performance over time, with an overall degradation rate comparable to that found in crystalline silicon systems.
Date: February 1, 2005
Creator: Adelstein, J. & Sekulic, B.
Object Type: Article
System: The UNT Digital Library
Relationship of Recombination Lifetime and Dark Current In Silicon p-n Junctions (open access)

Relationship of Recombination Lifetime and Dark Current In Silicon p-n Junctions

Measurement of recombination and minority-carrier lifetimes has become a central activity in photovoltaic technology. The primary measurement techniques for silicon technologies are based on photoconductive decay (PCD) and microwave reflectance (mPCD). The measurement of the correct recombination lifetime depends on the carriers being confined to a given spatial region of a diagnostic structure. The internal electric fields separate the charges, and the measured value does not represent the real minority-carrier lifetime. In these cases, the measured quantity is a function of the true lifetime and the sample structure. Here, we examine these effects, both experimentally and theoretically, for the n+-p device structure common to terrestrial photovoltaics.
Date: February 1, 2005
Creator: Ahrenkiel, R. K.; Metzger, W. K.; Page, M.; Reedy, R.; Luther, J. & Dashdorj, J.
Object Type: Article
System: The UNT Digital Library
Experiments Involving Correlations Between CdTe Solar Cell Fabrication History and Intrinsic Device Stability (open access)

Experiments Involving Correlations Between CdTe Solar Cell Fabrication History and Intrinsic Device Stability

An orthogonal full-factorial design was used to study the effect of CdS and CdTe layer thickness, oxygen ambient during vapor CdCl2 (VCC) and the use of nitric-phosphoric (NP) acid as a pre-contact etch on the initial and stressed performance of CdS/CdTe small-area devices. The best initial device efficiency (using thinner CdS, thicker CdTe, no oxygen during VCC, and NP etch) also showed poor stability. Increasing the CdS thickness significantly improved stability with only a slight decrease in resulting initial performance. All devices used a thin margin of CdTe around the perimeter of the backcontact that was shown to significantly reduce catastrophic degradation and improve overall test statistics. The latter degradation is modeled by the formation of a weak-diode/low shunt resistance localized near the edge of finished devices. This shunting is believed to occur through the CdS/CdTe interface, rather than along the device edge, and is exacerbated by thinner CdS films.
Date: February 1, 2005
Creator: Albin, D.; McMahon, T.; Berniard, T.; Pankow, J.; Demtsu, S. & Noufi, R.
Object Type: Article
System: The UNT Digital Library
Bounds on the neutrino mixing angles and CP phase for an SO(10) model with lopsided mass matrices (open access)

Bounds on the neutrino mixing angles and CP phase for an SO(10) model with lopsided mass matrices

None
Date: February 1, 2005
Creator: Albright, Carl H. & /Fermilab, /Northern Illinois U.
Object Type: Article
System: The UNT Digital Library
Advanced Fuel Cycle Initiative - Projected Linear Heat Generation Rate and Burnup Calculations (open access)

Advanced Fuel Cycle Initiative - Projected Linear Heat Generation Rate and Burnup Calculations

This report provides documentation of the physics analysis performed to determine the linear heat generation rate (LHGR) and burnup calculations for the Advanced Fuel Cycle Initiative (AFCI) tests, AFC-1D, AFC-1H, and AFC-1G. The AFC-1D and AFC-1H tests consists of low-fertile metallic fuel compositions and the AFC-1G test consists of non-fertile and low-fertile nitride compositions. These tests will be irradiated in the East Flux Trap (EFT) positions E1, E2, and E3, respectively, during Advanced Test Reactor (ATR) Cycle 135B.
Date: February 1, 2005
Creator: Ambrosek, Richard G.; Chang, Gray S. & Utterbeck, Debbie J.
Object Type: Report
System: The UNT Digital Library
Measurement of the branching ratios psi-prime ---> e+ e-, psi-prime ---> J/psi pi pi and psi-prime ---> J/psi eta (open access)

Measurement of the branching ratios psi-prime ---> e+ e-, psi-prime ---> J/psi pi pi and psi-prime ---> J/psi eta

The authors have measured several branching ratios for {psi}' decay using the data collected by FNAL E835 experiment during year 2000, obtaining {beta}({psi}' {yields} e{sup +}e{sup -}) = 0.0068 {+-} 0.0001 {+-} 0.0004, {beta}({psi}' {yields} J/{psi}{pi}{sup +}{pi}{sup -}) = 0.292 {+-} 0.005 {+-} 0.018, {beta}({psi}' {yields} J/{psi}{pi}{sup 0}{pi}{sup 0}) = 0.167 {+-} 0.005 {+-} 0.014 and {beta}({psi}' {yields} J/{psi}{eta}) = 0.028 {+-} 0.002 {+-} 0.002. They also present a measurement of the dipion mass distribution in the decays {psi}' {yields} J/{psi}{pi}{pi}.
Date: February 1, 2005
Creator: Andreotti, M.; Bagnasco, S.; Baldini, W.; Bettoni, D.; Borreani, G.; Buzzo, A. et al.
Object Type: Article
System: The UNT Digital Library
Development of an EMAT in-Line Inspection System for Detection, Discrimination, and Grading of Stress Corrosion Cracking in Pipelines Progress Report (open access)

Development of an EMAT in-Line Inspection System for Detection, Discrimination, and Grading of Stress Corrosion Cracking in Pipelines Progress Report

This report describes prototypes, measurements, and results for a project to develop a prototype pipeline in-line inspection (ILI) tool that uses electromagnetic acoustic transducers (EMATs) to detect and grade stress corrosion cracking (SCC). The introduction briefly provides motivation and describes SCC, gives some background on EMATs and guided ultrasonic waves, and reviews promising results of a previous project using EMATs for SCC. The experimental section then describes lab measurement techniques and equipment, the lab mouse and prototypes for a mule, and scan measurements made on SCC. The mouse was a moveable and compact EMAT setup. The prototypes were even more compact circuits intended to be pulled or used in an ILI tool. The purpose of the measurements was to determine the best modes, transduction, and processing to use, to characterize the transducers, and to prove EMATs and mule components could produce useful results. Next, the results section summarizes the measurements and describes the mouse scans, processing, prototype circuit operating parameters, and performance for SH0 scans. Results are given in terms of specifications--like SNR, power, insertion loss--and parametric curves--such as signal amplitude versus magnetic bias or standoff, reflection or transmission coefficients versus crack depth. Initially, lab results indicated magnetostrictive transducers using …
Date: February 1, 2005
Creator: Aron, Jeff; Jia, Jeff; Vance, Bruce; Chang, Wen; Pohler, Raymond; Gore, Jon et al.
Object Type: Report
System: The UNT Digital Library
Upper bounds on lepton-number violating processes (open access)

Upper bounds on lepton-number violating processes

None
Date: February 1, 2005
Creator: Atre, Anupama; Barger, Vernon; /Wisconsin U., Madison; Han, Tao & /Wisconsin U., Madison /Fermilab /Argonne
Object Type: Article
System: The UNT Digital Library
3rd Tech DeltaSphere-3000 Laser 3D Scene Digitizer infrared laser scanner hazard analysis. (open access)

3rd Tech DeltaSphere-3000 Laser 3D Scene Digitizer infrared laser scanner hazard analysis.

A laser hazard analysis and safety assessment was performed for the 3rd Tech model DeltaSphere-3000{reg_sign} Laser 3D Scene Digitizer, infrared laser scanner model based on the 2000 version of the American National Standard Institute's Standard Z136.1, for the Safe Use of Lasers. The portable scanner system is used in the Robotic Manufacturing Science and Engineering Laboratory (RMSEL). This scanning system had been proposed to be a demonstrator for a new application. The manufacture lists the Nominal Ocular Hazard Distance (NOHD) as less than 2 meters. It was necessary that SNL validate this NOHD prior to its use as a demonstrator involving the general public. A formal laser hazard analysis is presented for the typical mode of operation for the current configuration as well as a possible modified mode and alternative configuration.
Date: February 1, 2005
Creator: Augustoni, Arnold L.
Object Type: Report
System: The UNT Digital Library
PLUTONIUM FINISHING PLANT (PFP) GENERALIZED GEOMETRY HOLDUP CALCULATIONS & TOTAL MEASUREMENT UNCERTAINTY (open access)

PLUTONIUM FINISHING PLANT (PFP) GENERALIZED GEOMETRY HOLDUP CALCULATIONS & TOTAL MEASUREMENT UNCERTAINTY

A collimated portable gamma-ray detector will be used to quantify the plutonium content of items that can be approximated as a point, line, or area geometry with respect to the detector. These items can include ducts, piping, glove boxes, isolated equipment inside of gloveboxes, and HEPA filters. The Generalized Geometry Holdup (GGH) model is used for the reduction of counting data. This document specifies the calculations to reduce counting data into contained plutonium and the associated total measurement uncertainty.
Date: February 1, 2005
Creator: BD, KEELE
Object Type: Report
System: The UNT Digital Library
Joint Institute for Nanoscience Annual Report 2004 (open access)

Joint Institute for Nanoscience Annual Report 2004

Due to the inherently interdisciplinary nature of nanoscience and nanotechnology, research in this arena is often significantly enhanced through creative cooperative activities. The Joint Institute for Nanoscience (JIN) is a venture of the University of Washington (UW) and Pacific Northwest National Laboratory (PNNL) to encourage and enhance high impact and high quality nanoscience and nanotechnology research that leverages the strengths and capabilities of both institutions, and to facilitate education in these areas. This report summarizes JIN award activities that took place during fiscal year 2004 and provides a historical list of JIN awardees, their resulting publications, and JIN-related meetings. Major portions of the JIN efforts and resources are dedicated to funding graduate students and postdoctoral research associates to perform research in collaborations jointly directed by PNNL staff scientists and UW professors. JIN fellowships are awarded on the basis of applications that include research proposals. They have been very successful in expanding collaborations between PNNL and UW, which have led to many excellent joint publications and presentations and enhanced the competitiveness of both institutions for external grant funding. JIN-based interactions are playing a significant role in creating new research directions and reshaping existing research programs at both the UW and PNNL. …
Date: February 1, 2005
Creator: Baer, Donald R. & Campbell, Charles
Object Type: Report
System: The UNT Digital Library
Eye safe short range standoff aerosol cloud finder. (open access)

Eye safe short range standoff aerosol cloud finder.

Because many solid objects, both stationary and mobile, will be present in an indoor environment, the design of an indoor aerosol cloud finding lidar (light detection and ranging) instrument presents a number of challenges. The cloud finder must be able to discriminate between these solid objects and aerosol clouds as small as 1-meter in depth in order to probe suspect clouds. While a near IR ({approx}1.5-{micro}m) laser is desirable for eye-safety, aerosol scattering cross sections are significantly lower in the near-IR than at visible or W wavelengths. The receiver must deal with a large dynamic range since the backscatter from solid object will be orders of magnitude larger than for aerosol clouds. Fast electronics with significant noise contributions will be required to obtain the necessary temporal resolution. We have developed a laboratory instrument to detect aerosol clouds in the presence of solid objects. In parallel, we have developed a lidar performance model for performing trade studies. Careful attention was paid to component details so that results obtained in this study could be applied towards the development of a practical instrument. The amplitude and temporal shape of the signal return are analyzed for discrimination of aerosol clouds in an indoor environment. …
Date: February 1, 2005
Creator: Bambha, Ray P.; Schroder, Kevin L. & Reichardt, Thomas A.
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. Thermogravimetric analysis (TGA) was carried out on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} to investigate oxygen deficiency ({delta}) of the sample. The TGA was performed in a controlled atmosphere using oxygen, argon, carbon monoxide and carbon dioxide with adjustable gas flow rates. In this experiment, the weight loss and gain of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} was directly measured by TGA. The weight change of the sample was evaluated at between 600 and 1250 C in air or 1000 C as a function of oxygen partial pressure. The oxygen deficiencies calculated from TGA data as a function of oxygen activity and temperature will be estimated and compared with that from neutron diffraction measurement in air. The LSFT and LSFT/CGO membranes were fabricated from the powder obtained from Praxair Specialty Ceramics. The sintered membranes were subjected to microstructure analysis and hardness analysis. The LSFT membrane is composed of fine grains with two kinds of grain morphology. The grain size distribution was characterized using image analysis. In LSFT/CGO membrane a lot of …
Date: February 1, 2005
Creator: Bandopadhyay, S.; Nagabhushana, N.; Nithyanantham, T.; Zhou, X.-D; Sin, Y-W.; Anderson, H.U. 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. The in situ electrical conductivity and Seebeck coefficient measurements were made on LSFT at 1000 and 1200 C over the oxygen activity range from air to 10{sup -15} atm. The electrical conductivity measurements exhibited a p to n type transition at an oxygen activity of 1 x 10{sup -10} at 1000 C and 1 x 10{sup -6} at 1200 C. Thermogravimetric studies were also carried out over the same oxygen activities and temperatures. Based on the results of these measurements, the chemical and mechanical stability range of LSFT were determined and defect structure was established. The studies on the fracture toughness of the LSFT and dual phase membranes exposed to air and N{sub 2} at 1000 C was done and the XRD and SEM analysis of the specimens were carried out to understand the structural and microstructural changes. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affect the mechanical properties. A complete transformation of fracture behavior was …
Date: February 1, 2005
Creator: Bandopadhyay, S.; Nithyanantham, T.; Zhou, X.-D; Sin, Y-W.; Anderson, H.U.; Jacobson, Alan et al.
Object Type: Report
System: The UNT Digital Library
Characteristics and sources of intermediate size particles in recovery boilers : final project report. (open access)

Characteristics and sources of intermediate size particles in recovery boilers : final project report.

As part of the U.S. Department of Energy (DOE) Office of Industrial Technologies (OIT) Industries of the Future (IOF) Forest Products research program, a collaborative investigation was conducted on the sources, characteristics, and deposition of particles intermediate in size between submicron fume and carryover in recovery boilers. Laboratory experiments on suspended-drop combustion of black liquor and on black liquor char bed combustion demonstrated that both processes generate intermediate size particles (ISP), amounting to 0.5-2% of the black liquor dry solids mass (BLS). Measurements in two U.S. recovery boilers show variable loadings of ISP in the upper furnace, typically between 0.6-3 g/Nm{sup 3}, or 0.3-1.5% of BLS. The measurements show that the ISP mass size distribution increases with size from 5-100 {micro}m, implying that a substantial amount of ISP inertially deposits on steam tubes. ISP particles are depleted in potassium, chlorine, and sulfur relative to the fuel composition. Comprehensive boiler modeling demonstrates that ISP concentrations are substantially overpredicted when using a previously developed algorithm for ISP generation. Equilibrium calculations suggest that alkali carbonate decomposition occurs at intermediate heights in the furnace and may lead to partial destruction of ISP particles formed lower in the furnace. ISP deposition is predicted to occur …
Date: February 1, 2005
Creator: Baxter, Larry L. (Brigham Young University, Provo, UT); Shaddix, Christopher R.; Verrill, Christopher L. (Georgia Institute of Technology, Institute of Paper Science and Technology, Atlanta, GA) & Wessel, Richard A. (Babcock & Wilcox Company, Barberton, OH)
Object Type: Report
System: The UNT Digital Library
Redox Active Layer-by-Layer Structures containing MnO2 Nanoparticles (open access)

Redox Active Layer-by-Layer Structures containing MnO2 Nanoparticles

Nanoscale materials provide unique properties that will enable new technologies and enhance older ones. One area of intense activity in which nanoscale materials are being used is in the development of new functional materials for battery applications. This effort promises superior materials with properties that circumvent many of the problems associated with traditional battery materials. Previously we have worked on several approaches for using nanoscale materials for application as cathode materials in rechargeable Li batteries. Our recent work has focused on synthesizing MnO2 nanoparticles and using these in layer-by-layer (LbL) structures to probe the redox properties of the nanoparticles. We show that the aqueous colloidal nanoparticles produced by butanol reduction of tetramethylammonium permanganate can be trapped in thin films using a layer-by-layer deposition approach, and that these films are both redox active and exhibit kinetically facile electrochemical responses. We show cyclic voltammetry of MnO2 colloidal nanoparticles entrapped in a LbL thin film at an ITO electrode surface using poly(diallyldimethylammonium chloride) (PDDA). CV experiments demonstrate that Li+ insertion accompanies Mn(IV) reduction in LiClO4 supporting electrolytes, and that reduction is hindered in supporting electrolytes containing only tetrabutylammonium cations. We also show that electron propagation through multilayer films is facile, suggesting that electrons …
Date: February 1, 2005
Creator: Bazito, Fernanda; O'Brien, Robert & Buttry, Daniel A.
Object Type: Article
System: The UNT Digital Library
PILOT-AND FULL-SCALE DEMONSTRATION OF ADVANCED MERCURY CONTROL TECHNOLOGIES FOR LIGNITE-FIRED POWER PLANTS (open access)

PILOT-AND FULL-SCALE DEMONSTRATION OF ADVANCED MERCURY CONTROL TECHNOLOGIES FOR LIGNITE-FIRED POWER PLANTS

The overall objective of the project was to develop advanced innovative mercury control technologies to reduce mercury emissions by 50%-90% in flue gases typically found in North Dakota lignite-fired power plants at costs from one-half to three-quarters of current estimated costs. Power plants firing North Dakota lignite produce flue gases that contain >85% elemental mercury, which is difficult to collect. The specific objectives were focused on determining the feasibility of the following technologies: Hg oxidation for increased Hg capture in dry scrubbers, incorporation of additives and technologies that enhance Hg sorbent effectiveness in electrostatic precipitators (ESPs) and baghouses, the use of amended silicates in lignite-derived flue gases for Hg capture, and the use of Hg adsorbents within a baghouse. The approach to developing Hg control technologies for North Dakota lignites involved examining the feasibility of the following technologies: Hg capture upstream of an ESP using sorbent enhancement, Hg oxidation and control using dry scrubbers, enhanced oxidation at a full-scale power plant using tire-derived fuel and oxidizing catalysts, and testing of Hg control technologies in the Advanced Hybrid{trademark} filter.
Date: February 1, 2005
Creator: Benson, Steven A.; Crocker, Charlene R.; Galbreath, Kevin C.; Gunderson, Jay R.; Holmes, Michael J.; Laumb, Jason D. et al.
Object Type: Report
System: The UNT Digital Library
High Resolution Aerosol Modeling: Decadal Changes in Radiative Forcing (open access)

High Resolution Aerosol Modeling: Decadal Changes in Radiative Forcing

The Atmospheric Science Division of LLNL has performed high-resolution calculations of direct sulfate forcing using a DOE-provided computer resource at NERSC. We integrated our global chemistry-aerosol model (IMPACT) with the LLNL high-resolution global climate model (horizontal resolution as high as 100 km) to examine the temporal evolution of sulfate forcing since 1950. We note that all previous assessments of sulfate forcing reported in IPCC (2001) were based on global models with coarse spatial resolutions ({approx} 300 km or even coarser). However, the short lifetime of aerosols ({approx} days) results in large spatial and temporal variations of radiative forcing by sulfate. As a result, global climate models with coarse resolutions do not accurately simulate sulfate forcing on regional scales. It requires much finer spatial resolutions in order to address the effects of regional anthropogenic SO{sub 2} emissions on the global atmosphere as well as the effects of long-range transport of sulfate aerosols on the regional climate forcing. By taking advantage of the tera-scale computer resources at NERSC, we simulated the historic direct sulfate forcing at much finer spatial resolutions than ever attempted before. Furthermore, we performed high-resolution chemistry simulations and saved monthly averaged oxidant fields, which will be used in subsequent …
Date: February 1, 2005
Creator: Bergmann, D. J.; Chuang, C. C.; Govindasamy, B.; Cameron-Smith, P. J. & Rotman, D. A.
Object Type: Report
System: The UNT Digital Library
High Hydrogen Concentrations Detected In The Underground Vaults For RH-TRU Waste At INEEL Compared With Calculated Values Using The INEEL-Developed Computer Code (open access)

High Hydrogen Concentrations Detected In The Underground Vaults For RH-TRU Waste At INEEL Compared With Calculated Values Using The INEEL-Developed Computer Code

About 700 remote-handled transuranic (RH-TRU) waste drums are stored in about 144 underground vaults at the Intermediate-Level Transuranic Storage Facility at the Idaho National Environmental and Engineering Laboratory’s (INEEL’s) Radioactive Waste Management Complex (RWMC). These drums were shipped to the INEEL from 1976 through 1996. During recent monitoring, concentrations of hydrogen were found to be in excess of lower explosive limits. The hydrogen concentration in one vault was detected to be as high as 18% (by volume). This condition required evaluation of the safety basis for the facility. The INEEL has developed a computer program to estimate the hydrogen gas generation as a function of time and diffusion through a series of layers (volumes), with a maximum five layers plus a sink/environment. The program solves the first-order diffusion equations as a function of time. The current version of the code is more flexible in terms of user input. The program allows the user to estimate hydrogen concentrations in the different layers of a configuration and then change the configuration after a given time; e.g.; installation of a filter on an unvented drum or placed in a vault or in a shipping cask. The code has been used to predict vault …
Date: February 1, 2005
Creator: Bhatt, Rajiv & Khericha, Soli
Object Type: Article
System: The UNT Digital Library