[Catalyst research]. Final Report (open access)

[Catalyst research]. Final Report

Research results are the areas of catalyst precursor synthesis, catalyst fluxionality, catalyst stability, polymerization of {alpha}-olefins as well as the chemistry of Group IV and Group V metal centers with aryloxide and arylsulfide ligands.
Date: March 14, 2005
Creator: Rothwell, Ian P. & McMillin, David R.
Object Type: Report
System: The UNT Digital Library
Comparison of Convection Characteristics at the Tropical Western Pacific Darwin Site Between Observation and Global Climate Models Simulations (open access)

Comparison of Convection Characteristics at the Tropical Western Pacific Darwin Site Between Observation and Global Climate Models Simulations

One of the scientific objectives of the ARM Tropical Warm Pool International Cloud Experiment (TWPICE) planned for early 2006 at Darwin, Australia is to describe convection characteristics and its interaction with the large-scale fields. In view of the short duration of the experiment, it is important to determine the long-term statistics of convection and its associated clouds from the observations and global climate models (GCM) so as to put the experiment results in proper climate perspective. For this purpose, we examine several important fields associated with the characteristics of convection and the relationships between convection and clouds using GCM simulations and available satellite and surface observations. These include the seasonal variation of convection, the relationships between convection and the upper-level cloud amount, cloud ice water content and cloud radiative forcing. One major goal of the ARM program is to improve GCM cloud and convection parameterizations. Using NCAR Community Atmosphere Model (CAM3), we demonstrate that GCM simulations in the tropical western Pacific including Darwin can be significantly improved by improving convection parameterization.
Date: March 14, 2005
Creator: Zhang, G. J.
Object Type: Article
System: The UNT Digital Library
Density and Tensile Properties Changed by Aging Plutonium (open access)

Density and Tensile Properties Changed by Aging Plutonium

We present volume, density, and tensile property change observed from both naturally and accelerated aged plutonium alloys. Accelerated alloys are plutonium alloys with a fraction of Pu-238 to accelerate the aging process by approximately 18 times the rate of unaged weapons-grade plutonium. After thirty-five equivalent years of aging on accelerated alloys, the dilatometry shows the samples at 35 C have swelled in volume by 0.12 to 0.14% and now exhibit a near linear volume increase due to helium in-growth while showing possible surface effects on samples at 50 C and 65 C. The engineering stress of the accelerated alloy at 18 equivalent years increased significantly compared to at 4.5 equivalent years.
Date: March 14, 2005
Creator: Chung, B. W.; Choi, B. W.; Thompson, S. R.; Woods, C. H.; Hopkins, D. J. & Ebbinghaus, B. B.
Object Type: Article
System: The UNT Digital Library
Dynamic Data-Driven Event Reconstruction for Atmospheric Releases (open access)

Dynamic Data-Driven Event Reconstruction for Atmospheric Releases

This is a collaborative LDRD Exploratory Research project involving four directorates--Energy & Environment, Engineering, NAI and Computation. The project seeks to answer the following critical questions regarding atmospheric releases--''How much material was released? When? Where? and What are the potential consequences?'' Inaccurate estimation of the source term can lead to gross errors, time delays during a crisis, and even fatalities. We are developing a capability that seamlessly integrates observational data streams with predictive models in order to provide the best possible estimates of unknown source term parameters, as well as optimal and timely situation analyses consistent with both models and data. Our approach utilizes Bayesian inference and stochastic sampling methods (Markov Chain and Sequential Monte Carlo) to reformulate the inverse problem into a solution based on efficient sampling of an ensemble of predictive simulations, guided by statistical comparisons with data. We are developing a flexible and adaptable data-driven event-reconstruction capability for atmospheric releases that provides (1) quantitative probabilistic estimates of the principal source-term parameters (e.g., the time-varying release rate and location); (2) predictions of increasing fidelity as an event progresses and additional data become available; and (3) analysis tools for sensor network design and uncertainty studies. Our computational framework incorporates …
Date: March 14, 2005
Creator: Mirin, A; Serban, R & Kosovic, B
Object Type: Report
System: The UNT Digital Library
A Heavy Flavor Tracker for STAR (open access)

A Heavy Flavor Tracker for STAR

We propose to construct a Heavy Flavor Tracker (HFT) for the STAR experiment at RHIC. The HFT will bring new physics capabilities to STAR and it will significantly enhance the physics capabilities of the STAR detector at central rapidities. The HFT will ensure that STAR will be able to take heavy flavor data at all luminosities attainable throughout the proposed RHIC II era.
Date: March 14, 2005
Creator: Xu, Z.; Chen, Y.; Kleinfelder, S.; Koohi, A.; Li, S.; Huang, H. et al.
Object Type: Report
System: The UNT Digital Library
A Heavy Flavor Tracker for STAR (open access)

A Heavy Flavor Tracker for STAR

We propose to construct a Heavy Flavor Tracker (HFT) for theSTAR experiment at RHIC. The HFT will bring new physics capabilities toSTAR and it will significantly enhance the physics capabilities of theSTAR detector at central rapidities. The HFT will ensure that STAR willbe able to take heavy flavor data at all luminosities attainablethroughout the proposed RHIC II era.
Date: March 14, 2005
Creator: Xu, Z.; Chen, Y.; Kleinfelder, S.; Koohi, A.; Li, S.; Huang, H. et al.
Object Type: Report
System: The UNT Digital Library
Heterogeneous Chemistry: Understanding Aerosol/Oxidant Interactions (open access)

Heterogeneous Chemistry: Understanding Aerosol/Oxidant Interactions

Global radiative forcing of nitrate and ammonium aerosols has mostly been estimated from aerosol concentrations calculated at thermodynamic equilibrium or using approximate treatments for their uptake by aerosols. In this study, a more accurate hybrid dynamical approach (DYN) was used to simulate the uptake of nitrate and ammonium by aerosols and the interaction with tropospheric reactive nitrogen chemistry in a three-dimensional global aerosol and chemistry model, IMPACT, which also treats sulfate, sea salt and mineral dust aerosol. 43% of the global annual average nitrate aerosol burden, 0.16 TgN, and 92% of the global annual average ammonium aerosol burden, 0.29 TgN, exist in the fine mode (D<1.25 {micro}m) that scatters most efficiently. Results from an equilibrium calculation differ significantly from those of DYN since the fraction of fine-mode nitrate to total nitrate (gas plus aerosol) is 9.8%, compared to 13% in DYN. Our results suggest that the estimates of aerosol forcing from equilibrium concentrations will be underestimated. We also show that two common approaches used to treat nitrate and ammonium in aerosol in global models, including the first-order gas-to-particle approximation based on uptake coefficients (UPTAKE) and a hybrid method that combines the former with an equilibrium model (HYB), significantly overpredict the …
Date: March 14, 2005
Creator: Penner, Joyce E.
Object Type: Report
System: The UNT Digital Library
Key interactions in antibody recognition of synthetic sweeteners: Crystal structures of NC6.8 Fab co-crystallized with high potency sweetener compound SC45647 and with TES. (open access)

Key interactions in antibody recognition of synthetic sweeteners: Crystal structures of NC6.8 Fab co-crystallized with high potency sweetener compound SC45647 and with TES.

None
Date: March 14, 2005
Creator: Gokulan, K.; Khare, S.; Ronning, D.; Linthicum, S. D.; Rupp, B. & Sacchettini, J. C.
Object Type: Article
System: The UNT Digital Library
Locomotive Emission and Engine Idle Reduction Technology Demonstration Project (open access)

Locomotive Emission and Engine Idle Reduction Technology Demonstration Project

In response to a United States Department of Energy (DOE) solicitation, the Maryland Energy Administration (MEA), in partnership with CSX Transportation, Inc. (CSXT), submitted a proposal to DOE to support the demonstration of Auxiliary Power Unit (APU) technology on fifty-six CSXT locomotives. The project purpose was to demonstrate the idle fuel savings, the Nitrous Oxide (NOX) emissions reduction and the noise reduction capabilities of the APU. Fifty-six CSXT Baltimore Division locomotives were equipped with APUs, Engine Run Managers (ERM) and communications equipment to permit GPS tracking and data collection from the locomotives. Throughout the report there is mention of the percent time spent in the State of Maryland. The fifty-six locomotives spent most of their time inside the borders of Maryland and some spent all their time inside the state borders. Usually when a locomotive traveled beyond the Maryland State border it was into an adjoining state. They were divided into four groups according to assignment: (1) Power Unit/Switcher Mate units, (2) Remote Control units, (3) SD50 Pusher units and (4) Other units. The primary data of interest were idle data plus the status of the locomotive--stationary or moving. Also collected were main engine off, idling or working. Idle data …
Date: March 14, 2005
Creator: Archer, John R.
Object Type: Report
System: The UNT Digital Library
Pipelines as Communication Network Links (open access)

Pipelines as Communication Network Links

This report presents the results of an investigation into two methods of using the natural gas pipeline as a communication medium. The work addressed the need to develop secure system monitoring and control techniques between the field and control centers and to robotic devices in the pipeline. In the first method, the pipeline was treated as a microwave waveguide. In the second method, the pipe was treated as a leaky feeder or a multi-ground neutral and the signal was directly injected onto the metal pipe. These methods were tested on existing pipeline loops at UMR and Batelle. The results reported in this report indicate the feasibility of both methods. In addition, a few suitable communication link protocols for this network were analyzed.
Date: March 14, 2005
Creator: Erickson, Kelvin T.; Miller, Ann; Stanek, E. Keith; Wu, C. H. & Dunn-Norman, Shari
Object Type: Report
System: The UNT Digital Library
Preparing to Submit a License Application for Yucca Mountain (open access)

Preparing to Submit a License Application for Yucca Mountain

In 1982, the U.S. Congress passed the Nuclear Waste Policy Act, a Federal law that established U.S. policy for the permanent disposal of spent nuclear fuel and high-level radioactive waste. Congress amended the Act in 1987, directing the Department of Energy to study only Yucca Mountain, Nevada as the site for a permanent geologic repository. As the law mandated, the Department evaluated Yucca Mountain to determine its suitability as the site for a permanent geologic repository. Decades of scientific studies demonstrated that Yucca Mountain would protect workers, the public, and the environment during the time that a repository would be operating and for tens of thousands of years after closure of the repository. A repository at this remote site would also: preserve the quality of the environment; allow the environmental cleanup of Cold War weapons facilities; provide the nation with additional protection from acts of terrorism; and support a sound energy policy. Throughout the scientific evaluation of Yucca Mountain, there has been no evidence to disqualify Yucca Mountain as a suitable site for the permanent disposal of spent nuclear fuel and high-level radioactive waste. Upon completion of site characterization, the Secretary of Energy considered the results and concluded that a …
Date: March 14, 2005
Creator: Arthur, W.J. & Voegele, M.D.
Object Type: Report
System: The UNT Digital Library
Quantitative Molecular Thermochemistry Based on Path Integrals (open access)

Quantitative Molecular Thermochemistry Based on Path Integrals

The calculation of thermochemical data requires accurate molecular energies and heat capacities. Traditional methods rely upon the standard harmonic normal mode analysis to calculate the vibrational and rotational contributions. We utilize path integral Monte Carlo (PIMC) for going beyond the harmonic analysis, to calculate the vibrational and rotational contributions to ab initio energies. This is an application and extension of a method previously developed in our group.
Date: March 14, 2005
Creator: Glaesemann, K R & Fried, L E
Object Type: Article
System: The UNT Digital Library
Reliability Analysis of the Mechanical System in Selected Portions of the Nuclear HVAC System (open access)

Reliability Analysis of the Mechanical System in Selected Portions of the Nuclear HVAC System

None
Date: March 14, 2005
Creator: Ramirez, N.
Object Type: Report
System: The UNT Digital Library
Reply to 'Commentary: Assessment of past infiltration fluxes through Yucca Mountain on the basis of the secondary mineral record-is it a viable methodology?', by Y.V. Dublyansky and S.Z. Smirnov (open access)

Reply to 'Commentary: Assessment of past infiltration fluxes through Yucca Mountain on the basis of the secondary mineral record-is it a viable methodology?', by Y.V. Dublyansky and S.Z. Smirnov

Xu et al. (2003) presented results of a reaction-transport model for calcite deposition in the unsaturated zone at Yucca Mountain, and compared the model results to measured abundances in core from a surface-based borehole. Marshall et al. (2003) used the calcite distribution in the Topopah Spring Tuff to estimate past seepage into lithophysal cavities as an analog for seepage into the potential repository waste emplacement drifts at Yucca Mountain in southern Nevada (USA). Dublyansky and Smirnov (2005) wrote a commentary paper to Marshall et al. (2003) and Xu et al. (2003), containing two points: (1) questionable phenomenological model for the secondary mineral deposits and (2) inappropriate thermal boundary conditions. In this reply we address primarily the modeling approach by showing results of a sensitivity simulation regarding the effect of an elevated temperature history that approximates the temperature history inferred from fluid inclusions by Wilson et al. (2003). Modeled calcite abundances using the time-varying temperature history are similar to the results for the steady-state ambient temperature profile (Xu et al., 2003), and are still consistent with the measured abundances at the proposed repository horizon.
Date: March 14, 2005
Creator: Sonnenthal, Eric; Xu, Tianfu & Bodvarrson, Gudmundur
Object Type: Article
System: The UNT Digital Library
REPOSITORY SURFACE FACILITIES PRIMARY SYSTEM CRANE DATA (open access)

REPOSITORY SURFACE FACILITIES PRIMARY SYSTEM CRANE DATA

The purpose of this calculation is to compile crane design data for the mechanical primary structures, systems, and components (SSCs) required for the repository Waste Handling Building (WHB) and Carrier Preparation Building (CPB). The work presented in this document has been prepared in accordance with Office of Civilian Radioactive Waste Management approved program document AP-3.12Q, Calculations. This calculation has been developed to supplement information previously prepared using the development plan for ''WHB/WTB Space Program Analysis for Site Recommendation'' (Reference 5), which concentrates on the primary, primary support, facility support, and miscellaneous building support areas located in the WHB and Waste Treatment Building (WTB). The development plan was completed in accordance with AP-2.13Q, ''Technical Product Development Planning''. The work in this calculation is a continuance of the work described in the previous development plan; therefore, in accordance with AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', a new Technical Work Plan is not required.
Date: March 14, 2005
Creator: Schwartztrauber, K.
Object Type: Report
System: The UNT Digital Library
Sequential detection of a weak target in a hostile ocean environment (open access)

Sequential detection of a weak target in a hostile ocean environment

When the underlying physical phenomenology (medium, sediment, bottom, etc.) is space-time varying along with corresponding nonstationary statistics characterizing noise and uncertainties, then sequential methods must be applied to capture the underlying processes. Sequential detection and estimation techniques offer distinct advantages over batch methods. A reasonable signal processing approach to solve this class of problem is to employ adaptive or parametrically adaptive signal models and noise to capture these phenomena. In this paper, we develop a sequential approach to solve the signal detection problem in a nonstationary environment.
Date: March 14, 2005
Creator: Candy, J. V. & Sullivan, E. J.
Object Type: Article
System: The UNT Digital Library
TEM verification of the <111>-type 4-arm multi-junction in [001]-Mo single crystals (open access)

TEM verification of the <111>-type 4-arm multi-junction in [001]-Mo single crystals

To investigate and verify the formation of <111>-type 4-arm multi-junction by the dislocation reaction of 1/2[111] [b1] + 1/2[{bar 1}1{bar 1}] [b2] + 1/2[{bar 1}{bar 1}1] [b3] = 1/2[{bar 1}11] [b4], which has recently been discovered through computer simulations conducted by Vasily Bulatov and his colleagues.
Date: March 14, 2005
Creator: Hsiung, L
Object Type: Report
System: The UNT Digital Library