The 2.6 Angstrom resolution structure of Rhodobacter capsulatus bacterioferritin with metal-free dinuclear site and heme iron in a crystallographic 'special position' (open access)

The 2.6 Angstrom resolution structure of Rhodobacter capsulatus bacterioferritin with metal-free dinuclear site and heme iron in a crystallographic 'special position'

None
Date: October 31, 2001
Creator: Cobessi, D.; Huang, L.-S.; Ban, M.; Pon, N. G.; Daldal, F. & Berry, E. A.
Object Type: Article
System: The UNT Digital Library
3DIVS: 3-Dimensional Immersive Virtual Sculpting (open access)

3DIVS: 3-Dimensional Immersive Virtual Sculpting

Virtual Environments (VEs) have the potential to revolutionize traditional product design by enabling the transition from conventional CAD to fully digital product development. The presented prototype system targets closing the ''digital gap'' as introduced by the need for physical models such as clay models or mockups in the traditional product design and evaluation cycle. We describe a design environment that provides an intuitive human-machine interface for the creation and manipulation of three-dimensional (3D) models in a semi-immersive design space, focusing on ease of use and increased productivity for both designer and CAD engineers.
Date: October 3, 2001
Creator: Kuester, F; Duchaineau, M A; Hamann, B; Joy, K I & Uva, A E
Object Type: Article
System: The UNT Digital Library
Acceptable Knowledge Summary Report for Mixed TRU Waste Streams: SR-W026-221F-HET-A through D (open access)

Acceptable Knowledge Summary Report for Mixed TRU Waste Streams: SR-W026-221F-HET-A through D

This document, along with referenced supporting documents provides a defensible and auditable record of acceptable knowledge for the heterogeneous debris mixed transuranic waste streams generated in the FB-Line after January 25, 1990 and before March 20, 1997.
Date: October 2, 2001
Creator: Lunsford, G.F.
Object Type: Report
System: The UNT Digital Library
Accuracy of the Quasistatic Method for Two-Dimensional Thermal Reactor Transients with Feedback (open access)

Accuracy of the Quasistatic Method for Two-Dimensional Thermal Reactor Transients with Feedback

An important aspect in the design and safe operation of a nuclear reactor is the behavior of a reactor in a transient, or nonsteady state, condition. This study shows that the quasistatic method is capable of producing highly accurate results, relative to the direct finite-difference method, for two-dimensional thermal reactor transients with feedback.
Date: October 23, 2001
Creator: Dodds, H.L. Jr.
Object Type: Article
System: The UNT Digital Library
ACME - Algorithms for Contact in a Multiphysics Environment API Version 1.0 (open access)

ACME - Algorithms for Contact in a Multiphysics Environment API Version 1.0

An effort is underway at Sandia National Laboratories to develop a library of algorithms to search for potential interactions between surfaces represented by analytic and discretized topological entities. This effort is also developing algorithms to determine forces due to these interactions for transient dynamics applications. This document describes the Application Programming Interface (API) for the ACME (Algorithms for Contact in a Multiphysics Environment) library.
Date: October 1, 2001
Creator: BROWN, KEVIN H.; SUMMERS, RANDALL M.; GLASS, MICHEAL W.; GULLERUD, ARNE S.; HEINSTEIN, MARTIN W. & JONES, REESE E.
Object Type: Report
System: The UNT Digital Library
ACTIVE MODE CALIBRATION OF THE COMBINED THERMAL EPITHERMAL NEUTRON (CTEN) SYSTEM (open access)

ACTIVE MODE CALIBRATION OF THE COMBINED THERMAL EPITHERMAL NEUTRON (CTEN) SYSTEM

None
Date: October 1, 2001
Creator: Veilleux, J. M.
Object Type: Article
System: The UNT Digital Library
The Activities of the International Criticality Safety Benchmark Evaluation Project (ICSBEP) (open access)

The Activities of the International Criticality Safety Benchmark Evaluation Project (ICSBEP)

The International Criticality Safety Benchmark Evaluation Project (ICSBEP) was initiated in 1992 by the United States Department of Energy. The ICSBEP became an official activity of the Organization for Economic Cooperation and Development (OECD) – Nuclear Energy Agency (NEA) in 1995. Representatives from the United States, United Kingdom, France, Japan, the Russian Federation, Hungary, Republic of Korea, Slovenia, Yugoslavia, Kazakhstan, Spain, and Israel are now participating. The purpose of the ICSBEP is to identify, evaluate, verify, and formally document a comprehensive and internationally peer-reviewed set of criticality safety benchmark data. The work of the ICSBEP is published as an OECD handbook entitled “International Handbook of Evaluated Criticality Safety Benchmark Experiments”. The 2001 Edition of the Handbook contains benchmark specifications for 2642 critical or subcritical configurations that are intended for use in validation efforts and for testing basic nuclear data.
Date: October 1, 2001
Creator: Briggs, Joseph Blair
Object Type: Article
System: The UNT Digital Library
Adaptive Sensor Optimization and Cognitive Image Processing Using Autonomous Optical Neuroprocessors (open access)

Adaptive Sensor Optimization and Cognitive Image Processing Using Autonomous Optical Neuroprocessors

Measurement and signal intelligence demands has created new requirements for information management and interoperability as they affect surveillance and situational awareness. Integration of on-board autonomous learning and adaptive control structures within a remote sensing platform architecture would substantially improve the utility of intelligence collection by facilitating real-time optimization of measurement parameters for variable field conditions. A problem faced by conventional digital implementations of intelligent systems is the conflict between a distributed parallel structure on a sequential serial interface functionally degrading bandwidth and response time. In contrast, optically designed networks exhibit the massive parallelism and interconnect density needed to perform complex cognitive functions within a dynamic asynchronous environment. Recently, all-optical self-organizing neural networks exhibiting emergent collective behavior which mimic perception, recognition, association, and contemplative learning have been realized using photorefractive holography in combination with sensory systems for feature maps, threshold decomposition, image enhancement, and nonlinear matched filters. Such hybrid information processors depart from the classical computational paradigm based on analytic rules-based algorithms and instead utilize unsupervised generalization and perceptron-like exploratory or improvisational behaviors to evolve toward optimized solutions. These systems are robust to instrumental systematics or corrupting noise and can enrich knowledge structures by allowing competition between multiple hypotheses. This property …
Date: October 1, 2001
Creator: CAMERON, STEWART M.
Object Type: Report
System: The UNT Digital Library
The Adjoint Method for The Optimization of Brachytherapy and Radiotherapy Patient Treatment Planning Procedures Using Monte Carlo Calculations (open access)

The Adjoint Method for The Optimization of Brachytherapy and Radiotherapy Patient Treatment Planning Procedures Using Monte Carlo Calculations

The goal of this project is to investigate the use of the adjoint method, commonly used in the reactor physics community, for the optimization of radiation therapy patient treatment plans. Two different types of radiation therapy are being examined, interstitial brachytherapy and radiotherapy. In brachytherapy radioactive sources are surgically implanted within the diseased organ such as the prostate to treat the cancerous tissue. With radiotherapy, the x-ray source is usually located at a distance of about 1-metere from the patient and focused on the treatment area. For brachytherapy the optimization phase of the treatment plan consists of determining the optimal placement of the radioactive sources, which delivers the prescribed dose to the disease tissue while simultaneously sparing (reducing) the dose to sensitive tissue and organs. For external beam radiation therapy the optimization phase of the treatment plan consists of determining the optimal direction and intensity of beam, which provides complete coverage of the tumor region with the prescribed dose while simultaneously avoiding sensitive tissue areas. For both therapy methods, the optimal treatment plan is one in which the diseased tissue has been treated with the prescribed dose and dose to the sensitive tissue and organs has been kept to a …
Date: October 30, 2001
Creator: Henderson, D. L.; Yoo, S.; Kowalok, M.; Mackie, T. R. & Thomadsen, B. R.
Object Type: Report
System: The UNT Digital Library
Advanced Analysis Methods in High Energy Physics (open access)

Advanced Analysis Methods in High Energy Physics

During the coming decade, high energy physics experiments at the Fermilab Tevatron and around the globe will use very sophisticated equipment to record unprecedented amounts of data in the hope of making major discoveries that may unravel some of Nature's deepest mysteries. The discovery of the Higgs boson and signals of new physics may be around the corner. The use of advanced analysis techniques will be crucial in achieving these goals. The author discusses some of the novel methods of analysis that could prove to be particularly valuable for finding evidence of any new physics, for improving precision measurements and for exploring parameter spaces of theoretical models.
Date: October 3, 2001
Creator: Bhat, Pushpalatha C.
Object Type: Article
System: The UNT Digital Library
Advanced Computational Model for Three-Phase Slurry Reactors Progress Report: October 2001 (open access)

Advanced Computational Model for Three-Phase Slurry Reactors Progress Report: October 2001

In the second year of the project, the Eulerian-Lagrangian formulation for analyzing three-phase slurry flows in a bubble column is further developed. The approach uses an Eulerian analysis of liquid flows in the bubble column, and makes use of the Lagrangian trajectory analysis for the bubbles and particle motions. An experimental set for studying a two-dimensional bubble column is also developed. The operation of the bubble column is being tested and diagnostic methodology for quantitative measurements is being developed. An Eulerian computational model for the flow condition in the two-dimensional bubble column is also being developed. The liquid and bubble motions are being analyzed and the results are being compared with the experimental setup. Solid-fluid mixture flows in ducts and passages at different angle of orientations were analyzed. The model predictions were compared with the experimental data and good agreement was found. Gravity chute flows of solid-liquid mixtures is also being studied. Further progress was also made in developing a thermodynamically consistent model for multiphase slurry flows with and without chemical reaction in a state of turbulent motion. The balance laws are obtained and the constitutive laws are being developed. Progress was also made in measuring concentration and velocity of …
Date: October 1, 2001
Creator: Ahmadi, Goodarz
Object Type: Report
System: The UNT Digital Library
ADVANCED FLUE GAS CONDITIONING AS A RETROFIT UPGRADE TO ENHANCE PM COLLECTION FROM COAL-FIRED ELECTRIC UTILITY BOILERS (open access)

ADVANCED FLUE GAS CONDITIONING AS A RETROFIT UPGRADE TO ENHANCE PM COLLECTION FROM COAL-FIRED ELECTRIC UTILITY BOILERS

The U.S. Department of Energy and ADA Environmental Solutions are engaged in a project to develop commercial flue gas conditioning additives. The objective is to develop conditioning agents that can help improve particulate control performance of smaller or under-sized electrostatic precipitators on utility coal-fired boilers. The new chemicals will be used to control both the electrical resistivity and the adhesion or cohesivity of the fly ash. There is a need to provide cost-effective and safer alternatives to traditional flue gas conditioning with SO{sub 3} and ammonia. During this reporting quarter, progress was made in obtaining an industry partner for a long-term demonstration and in technology transfer activities. Engineering and equipment procurement activities related to the long-term demonstration were also completed.
Date: October 1, 2001
Creator: Baldrey, Kenneth E.
Object Type: Report
System: The UNT Digital Library
ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS (open access)

ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

Eltron Research Inc., and team members CoorsTek, McDermott Technology, Inc., Sued Chemie, Argonne National Laboratory and Oak Ridge National Laboratory are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying single-phase and composite membrane composition and microstructure to maximize proton and electron conductivity without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this quarter, mixed proton/electron conductivity and hydrogen transport was measured as a function of metal phase content for a range of ceramic/metal (cermet) compositions. It was found that optimum performance occurred at 44 wt.% metal content for all compositions tested. Although each cermet appeared to have a continuous …
Date: October 30, 2001
Creator: Roark, Shane E.; Sammells, Tony F.; Mackay, Richard A.; Pitzman, Lyrik Y.; LaGuardia, Alexandra Z.; Barton, Tom F. et al.
Object Type: Report
System: The UNT Digital Library
Advanced Oil Recovery Technologies for Improved Recovery From Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, Nm (open access)

Advanced Oil Recovery Technologies for Improved Recovery From Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, Nm

The Nash Draw Brushy Canyon Pool (NDP) in southeast New Mexico is one of the nine projects selected in 1995 by the U.S. Department of Energy (DOE) for participation in the Class III Reservoir Field Demonstration Program. The goals of the DOE cost-shared Class Program are to: (1) extend economic production, (2) increase ultimate recovery, and (3) broaden information exchange and technology application. Reservoirs in the Class III Program are focused on slope basin and deep-basin clastic depositional types. Production at the NDP is from the Brushy Canyon formation, a low-permeability turbidite reservoir in the Delaware Mountain Group of Permian, Guadalupian age. A major challenge in this marginal-quality reservoir is to distinguish oil-productive pay intervals from water-saturated non-pay intervals. Because initial reservoir pressure is only slightly above bubble-point pressure, rapid oil decline rates and high gas/oil ratios are typically observed in the first year of primary production. Limited surface access, caused by the proximity of underground potash mining and surface playa lakes, prohibits development with conventional drilling. Reservoir characterization results obtained to date at the NDP show that a proposed pilot injection area appears to be compartmentalized. Because reservoir discontinuities will reduce effectiveness of a pressure maintenance project, the pilot …
Date: October 31, 2001
Creator: Murphy, Mark B.
Object Type: Report
System: The UNT Digital Library
ADVANCED TECHNOLOGIES FOR STRIPPER GAS WELL ENHANCEMENT (open access)

ADVANCED TECHNOLOGIES FOR STRIPPER GAS WELL ENHANCEMENT

As part of Task 1 in Advanced Technologies for Stripper Gas Well Enhancement, Schlumberger--Holditch Reservoir Technologies (H-RT) has joined with two Appalachian Basin producers, Great Lakes Energy Partners, LLC, and Belden & Blake Corporation to develop methodologies for identification and enhancement of stripper wells with economic upside potential. These industry partners have provided us with data for more than 700 wells in northwestern Pennsylvania. Phase 1 goals of this project are to develop and validate methodologies that can quickly and cost-effectively identify wells with enhancement potential. We have continued to enhance and streamline our software, and we are testing the final stages of our new Microsoft{trademark} Access/Excel based software. We are continuing to process this well data and are identifying potential candidate wells that can be used in Phase 2 to validate the new methodologies. In addition, preparation of the final technical report is underway.
Date: October 1, 2001
Creator: Boyer, Charles M., II & MacDonald, Ronald J.
Object Type: Report
System: The UNT Digital Library
Advanced Tokamak Scenarios for the FIRE Burning Plasma Experiment (open access)

Advanced Tokamak Scenarios for the FIRE Burning Plasma Experiment

The advanced tokamak (AT) capability of the Fusion Ignition Research Experiment (FIRE) burning plasma experiment is examined with 0-D systems analysis, equilibrium and ideal-MHD stability, radio-frequency current-drive analysis, and full discharge dynamic simulations. These analyses have identified the required parameters for attractive burning advanced tokamak plasmas, and indicate that these are feasible with the present progress on existing experimental tokamaks.
Date: October 12, 2001
Creator: Kessel, C.E.; Ignat, D. & Mau, T.K.
Object Type: Report
System: The UNT Digital Library
Aggregation of the neodymium complexes of HDEHP, Cyanex 272, Cyanex 302, and Cyanex 301 in toluene. (open access)

Aggregation of the neodymium complexes of HDEHP, Cyanex 272, Cyanex 302, and Cyanex 301 in toluene.

None
Date: October 18, 2001
Creator: Jensen, M. P.; Chiarizia, R.; Urban, V. & Nash, K. L.
Object Type: Article
System: The UNT Digital Library
AISI/DOE Technology Roadmap Program: Behavior of Phosphorus in DRI/HBI During Electric Furnace Steelmaking (open access)

AISI/DOE Technology Roadmap Program: Behavior of Phosphorus in DRI/HBI During Electric Furnace Steelmaking

Many common scrap substitutes such as direct reduced iron pellets (DRI), hot briquetted iron (HBI), iron carbide, etc., contain significantly higher levels of phosphorus steelmaking for the production of higher quality steels, control of phosphorus levels in the metal will become a concern. This study has developed a more complete understanding of the behavior of phosphorus in DRI during EAF steelmaking, through a thorough investigation of the kinetics and thermodynamics of phosphorus transfer in the EAF based upon laboratory and plant experiments and trials. Laboratory experiments have shown that phosphorus mass transfer between oxide and metallic phases within commercial direct reduced iron pellets occurs rapidly upon melting according to the local equilibrium for these phases. Laboratory kinetic experiments indicate that under certain conditions, phosphorus mass transfer between slag and metal is influenced by dynamic phenomena, which affect the mass transfer coefficient for the reaction and/or the slag metal interfacial area. Plant trials were conducted to directly evaluate the conditions of mass transfer in the electric furnace and to determine the effects of different scrap substitute materials upon the slag chemistry, the behavior of phosphorus in the steel, and upon furnace yield. The data from these trials were also used to …
Date: October 5, 2001
Creator: Frueham, Richard J. & Manning, Christopher P.
Object Type: Report
System: The UNT Digital Library
Algorithms for deriving crystallographic space-group information. II: Treatment of special positions (open access)

Algorithms for deriving crystallographic space-group information. II: Treatment of special positions

Algorithms for the treatment of special positions in 3-dimensional crystallographic space groups are presented. These include an algorithm for the determination of the site-symmetry group given the coordinates of a point, an algorithm for the determination of the exact location of the nearest special position, an algorithm for the assignment of a Wyckoff letter given the site-symmetry group, and an alternative algorithm for the assignment of a Wyckoff letter given the coordinates of a point directly. All algorithms are implemented in ISO C++ and are integrated into the Computational Crystallography Toolbox. The source code is freely available.
Date: October 5, 2001
Creator: Grosse-Kunstleve, Ralf W. & Adams, Paul D.
Object Type: Article
System: The UNT Digital Library
The Alpha Dynamo Effects in Laboratory Plasmas (open access)

The Alpha Dynamo Effects in Laboratory Plasmas

A concise review of observations of the alpha dynamo effect in laboratory plasmas is given. Unlike many astrophysical systems, the laboratory pinch plasmas are driven magnetically. When the system is overdriven, the resultant instabilities cause magnetic and flow fields to fluctuate, and their correlation induces electromotive forces along the mean magnetic field. This alpha-effect drives mean parallel electric current, which, in turn, modifies the initial background mean magnetic structure towards the stable regime. This drive-and-relax cycle, or the so-called self-organization process, happens in magnetized plasmas in a timescale much shorter than resistive diffusion time, thus it is a fast and unquenched dynamo process. The observed alpha-effect redistributes magnetic helicity (a measure of twistedness and knottedness of magnetic field lines) but conserves its total value. It can be shown that fast and unquenched dynamos are natural consequences of a driven system where fluctuations are statistically either not stationary in time or not homogeneous in space, or both. Implications to astrophysical phenomena will be discussed.
Date: October 16, 2001
Creator: Ji, Hantao & Prager, Stewart C.
Object Type: Report
System: The UNT Digital Library
Alternative Solar-Grade Silicon Feedstock Approaches: Preprint (open access)

Alternative Solar-Grade Silicon Feedstock Approaches: Preprint

Presented at the 2001 NCPV Program Review Meeting: Report on research on four alternative methods for purifying metallurgical-grade silicon to target levels suitable for solar-grade silicon.
Date: October 1, 2001
Creator: Ciszek, T. F.; Wang, T. H.; Page, M. R.; Menna, P.; Bauer, R. E.; Good, E. A. et al.
Object Type: Article
System: The UNT Digital Library
AMBIENT PM2.5 SAMPLING AND ANALYSIS (open access)

AMBIENT PM2.5 SAMPLING AND ANALYSIS

This interim report summarizes detailed findings and conclusions drawn from evaluations of data obtained from the operation of ambient PM{sub 2.5} speciation sites in a geographical area encompassing southeastern Ohio, western Pennsylvania and northwestern West Virginia. The overall goal of this program, called the Upper Ohio River Valley Project (UORVP), is to better understand the relationship between coal-based power system emissions and ambient air quality in the Upper Ohio River Valley region through the collection of chemically resolved or speciated data. A summary of the sampling activities, sample analyses and the correlation and interpretation of data acquired from February 1999 through March of 2001 are reported. Mass and speciated data from urban and rural sources are compared and seasonal variations in PM{sub 2.5} distribution are also examined. Correlations between meteorological parameters and total PM{sub 2.5} mass are also presented.
Date: October 31, 2001
Creator: unknown
Object Type: Report
System: The UNT Digital Library
ANALYSIS OF A CLAD TUNGSTEN TARGET AFTER IRRADIATION IN AN 800 MEV PROTON BEAM (open access)

ANALYSIS OF A CLAD TUNGSTEN TARGET AFTER IRRADIATION IN AN 800 MEV PROTON BEAM

None
Date: October 1, 2001
Creator: MALOY, S. A.; JAMES, M. R. & SOMMER, W. F.
Object Type: Article
System: The UNT Digital Library
Analysis of Nitrogen Incorporation in Group III-Nitride-Arsenide Materials Using a Magnetic Sector Secondary-Ion Mass Spectrometry (SIMS) Instrument: Preprint (open access)

Analysis of Nitrogen Incorporation in Group III-Nitride-Arsenide Materials Using a Magnetic Sector Secondary-Ion Mass Spectrometry (SIMS) Instrument: Preprint

Presented at the 2001 NCPV Program Review Meeting: Group III-nitride-arsenide materials were studied by SIMS, XRD, and Profiler to determine small amounts of nitrogen that can lower the alloys bandgap significantly.
Date: October 1, 2001
Creator: Reedy, R. C.; Geisz, J. F.; Kurtz, S. R.; Adams, R. O. & Perkins, C. L.
Object Type: Article
System: The UNT Digital Library