2001 Gordon Research Conference on Organometallic Chemistry. Final progress report [agenda and attendee list] (open access)

2001 Gordon Research Conference on Organometallic Chemistry. Final progress report [agenda and attendee list]

The Gordon Research Conference on Organometallic Chemistry was held at Salve Regina University, Newport, Rhode Island, July 22-27, 2001. The conference had 133 participants. The attendees represented the spectrum of endeavor in this field, coming from academia, industry, and government laboratories, and included US and foreign scientists, senior researchers, young investigators, and students. Emphasis was place on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions; poster sessions were held.
Date: July 27, 2001
Creator: Burns, Carol
Object Type: Report
System: The UNT Digital Library
Arbitrarily High Order Transport Method of the Characteristic Type for Tetrahedral Grids (open access)

Arbitrarily High Order Transport Method of the Characteristic Type for Tetrahedral Grids

A formalism is derived for the Arbitrarily High Order Transport (AHOT) method of the Characteristic type (AHOT-C) in three-dimensional geometry for unstructured grids (UG). The resulting equations are implemented in a computer code, AHOT-C-UG, in the C language. The transport solution on the unstructured grid is stored as two inter-linked lists of cell and face flux moments. This arrangement allows the transport sweep to select the order of evaluation dynamically so that the typical recursive ordering of the discrete ordinate's mesh sweep is maintained without the need to store a precomputed order for each ordinate. The dynamic cell sweep order thus reduces the memory demand without excessively increasing execution time. Comparison of AHOT-C-UG's solutions to fine mesh TORT solutions illustrate high accuracy of the new method. In particular, large half a million cell numerical tests illustrate a convergence rate for the error as O(h), where h is a measure of the longest edge in the tetrahedral grid. Execution time on a 700 MHz Intel Pentium III running Linux 2.4.0 is less than 0.2 ms per cell-angle sweep operation. Also the total memory requirement is of the order of 240 bytes per tetrahedral cell, where 64-bit arithmetic precision is employed throughout.
Date: June 27, 2001
Creator: Azmy, Y. Y.
Object Type: Article
System: The UNT Digital Library
Beryllium Materials for National Ignition Facility Targets LDRD Final Report (open access)

Beryllium Materials for National Ignition Facility Targets LDRD Final Report

The National Ignition Facility (NIF) will require spherical ignition capsules approximately 2 mm in diameter with a 120- to 150-pm-thick ablator. Beryllium-based alloys are promising candidates for an ablator material due to their combination of low opacity and relatively high density (compared to polymer coatings). For optimum performance, the Be-coated capsules require a smooth surface finish, uniform thickness, microscopic homogeneity, and preferably high strength. The coatings must contain on the order of 1 at.% of a high-Z dopant (such as Cu) and permit the capsule to be filled with fuel, which will be a mixture of hydrogen isotopes. These demanding requirements can be met through a synthesis method with a focus on the control of microstructure. In our experiments, the sputter deposition process has been manipulated so as to decrease the grain size, thereby reducing roughness and improving homogeneity. The material properties of sputter-deposited coatings are sensitive to their microstructure and growth morphology. To meet the requirements for Be coated capsules, the goal of this project was to optimize the microstructure and growth morphology through the control of deposition process parameters. Prior experimental studies of evaporation and sputter deposition revealed that the grain size of 99.8 at.% pure Be can …
Date: February 27, 2001
Creator: McEachern, R L
Object Type: Report
System: The UNT Digital Library
Breeding 10{sup 10}/s Radioactive Nuclei in a Compact Plasma Focus Device (open access)

Breeding 10{sup 10}/s Radioactive Nuclei in a Compact Plasma Focus Device

In the early 90's, it was discovered that a Plasma Focus (PF) system self-creates a plasma-tarp in which high energy-threshold nuclear-reactions occur at high reaction rates. Short life radioisotopes (SLR)s such as {sup 18}F, {sup 17}F, {sup 15}O, {sup 14}O, {sup 13}N have been generated (10{sup 6} - 10{sup 8} per pulse) with a PF-machine using 7 kJ energy storage to produce the plasmas. {beta}{sup -} radioactivity from the SLRs is measured with rugged, Geiger counters inserted into the PF-chamber, and a specific SLR is identified by its half-life. The PF chamber (before discharge) is filled with a mixture of gases that constitutes the latter plasma-target--beam system, e.g., the elements required to produce specific SLRs through nuclear reactions. In this paper, arguments are presented showing that a modest sized PF-machine, using a 50-75 kJ fast capacitor-bank, when operated at pulse frequencies of 1-10 Hz can produce {ge} 10{sup 9} SLRs/pulse. This paper reports the result s of testing a PF as a breeder of SLRs with dual applications for: (1) Secondary Radioactive Nuclear Beams ion-sources (Z < 35), and (2) as a breeder of radioisotopes for biomedicine (Z {le} 10) and/or PET imaging.
Date: July 27, 2001
Creator: Brzosko, JANS.
Object Type: Article
System: The UNT Digital Library
A case study in application I/O on Linux clusters. (open access)

A case study in application I/O on Linux clusters.

A critical but often ignored component of system performance is the I/O system. Today's applications expect a great deal from underlying storage systems and software, and both high performance distributed storage and high level interfaces have been developed to fill these needs. In this paper they discuss the I/O performance of a parallel scientific application on a Linux cluster, the FLASH astrophysics code. This application relies on three I/O software components to provide high performance parallel I/O on Linux clusters: the Parallel Virtual File System (PVFS), the ROMIO MPI-IO implementation, and the Hierarchical Data Format (HDF5) library. First they discuss the roles played by each of these components in providing an I/O solution. Next they discuss the FLASH I/O benchmark and point out its relevance. Following this they examine the performance of the benchmark, and through instrumentation of both the application and underlying system software code they discover the location of major software bottlenecks. They work around the most inhibiting of these bottlenecks, showing substantial performance improvement. Finally they point out similarities between the inefficiencies found here and those found in message passing systems, indicating that research in the message passing field could be leveraged to solve similar problems in …
Date: July 27, 2001
Creator: Ross, R.; Nurmi, D.; Cheng, A. & Zingale, M.
Object Type: Article
System: The UNT Digital Library
The CDF data acquisition system for Tevatron Run II (open access)

The CDF data acquisition system for Tevatron Run II

The CDF experiment at the Fermilab Tevatron has been significantly upgraded for the collider Run II, which started in March 2001 and is scheduled to last until 2006. Instantaneous luminosities of 10{sup 32} cm{sup -2} s{sup -1} and above are expected. A data acquisition system capable of efficiently recording the data has been one of the most critical elements of the upgrade. Key figures are the ability to deal with the short bunch spacing of 132 ns, event sizes of the order of 250 kB, and permanent logging of 20 MB/s. The design of the system and experience from the first months of data-taking operation are discussed.
Date: August 27, 2001
Creator: Meyer, Arnd
Object Type: Article
System: The UNT Digital Library
The CDF Run 2 Offline Computer Farms (open access)

The CDF Run 2 Offline Computer Farms

Run 2 at Fermilab began in March 2001. CDF will collect data at a maximum rate of 20 MByte/sec during the run. The offline reconstruction of this data must keep up with the data taking rate. This reconstruction occurs on a large PC farm, which must have the capacity for quasi-real time data reconstruction, for reprocessing of some data and for generation and processing of Monte Carlo samples. In this paper they give the design requirements for the farm, describe the hardware and software design used to meet those requirements, describe the early experiences with Run 2 data processing, and discuss future prospects for the farm, including some ideas about Run 2b processing.
Date: August 27, 2001
Creator: al., Jaroslav Antos et
Object Type: Article
System: The UNT Digital Library
Ceramic Membranes for Hydrogen Production From Coal (open access)

Ceramic Membranes for Hydrogen Production From Coal

The present project is devoted to developing hydrogen permselective silica membranes supported on composite supports to achieve high flux and selectivity. The supports consist of a thin zeolite silicalite layer coated on {alpha}-Al{sub 2}O{sub 3} tubes of mean pore size 1 {micro}m. The zeolite layer is grown by reaction in a suitable silicate solution at 95 C. After two or three reaction periods a layer of silicalite crystals about 20 {micro}m thick grows inside the pores of alumina. In addition to the zeolitic pores, this layer contains voids of a few nanometer diameter that remain between the crystals or between the crystals and the pore walls. The quality of the silicalite/alumina composites was evaluated by gas permeation measurements and by nitrogen adsorption and it was found that the residual voids were below 5 nm in diameter. Three techniques were investigated for chemical vapor deposition (CVD) of the silica layer on the silicalite/alumina composite support. The first was TEOS pyrolysis at approximately one millibar partial pressure and 650 C. After 8 h reaction the fluxes of hydrogen and nitrogen at ambient temperature had declined by a factor of approximately 100 indicating sealing of defects and zeolitic pores alike. The second CVD …
Date: November 27, 2001
Creator: Gavalas, George R.
Object Type: Report
System: The UNT Digital Library
Characterization of Contaminant Transport by Gravity, Capillarity and Barometric Pumping in Heterogeneous Vadose Zones (open access)

Characterization of Contaminant Transport by Gravity, Capillarity and Barometric Pumping in Heterogeneous Vadose Zones

This final report summarizes the work and accomplishments of our three-year project. We have pursued the concept of a Vadose-Zone Observatory (VZO) to provide the field laboratory necessary for carrying out the experiments required to achieve the goals of this research. Our approach has been (1) to carry out plume release experiments at a VZO allowing the acquisition of several different kinds of raw data that (2) are analyzed and evaluated with the aid of highly detailed, diagnostic numerical models. The key feature of the VZO constructed at Lawrence Livermore National Laboratory (LLNL) is the variety of plume-tracking techniques that can be used at a single location. Electric resistance tomography (ERT) uses vertical arrays of electrodes across the vadose zone that can monitor electrical resistance changes in the soil as a plume moves downward to the water table. These resistance changes can be used to provide ''snapshots'' of the progress of the plume. Additionally, monitoring wells have been completed at multiple levels in the vicinity of a central infiltration site. Sensors emplaced at different levels include electrically conducting gypsum blocks for detecting saturation changes, thermistors for monitoring temperature changes and pressure transducers for observing barometric changes at different levels in …
Date: February 27, 2001
Creator: Carrigan, C R; Martins, S A; Ramirez, A L; Daily, W D; Hudson, G B; Ralsont, D et al.
Object Type: Report
System: The UNT Digital Library
Charging Algorithm Extends the Life of Lead-acid Batteries: 2001 R and D 100 Award Recipient (open access)

Charging Algorithm Extends the Life of Lead-acid Batteries: 2001 R and D 100 Award Recipient

Fact sheet describing NREL's work with Recombination Technologies and Optima Batteries to develop a current interrupt charging algorithm to extend the deep life cycle of valve-regulated lead-acid batteries.
Date: September 27, 2001
Creator: Pesaran, A.
Object Type: Book
System: The UNT Digital Library
Clean Cities Goes International: Clean Cities International Program Fact Sheet (open access)

Clean Cities Goes International: Clean Cities International Program Fact Sheet

A brief overview of the Clean Cities International program, including background and plans for the future.
Date: April 27, 2001
Creator: LaRocque, T.
Object Type: Book
System: The UNT Digital Library
Comparison of Theory with Rotation Measurements in JET ICRH Plasmas (open access)

Comparison of Theory with Rotation Measurements in JET ICRH Plasmas

Plasma rotation appears to improve plasma performance by increasing the E x B flow shearing rate, thus decreasing radial correlations in the microturbulence. Also, plasma rotation can increase the stability to resistive MHD modes. In the Joint European Torus (JET), toroidal rotation rates omega (subscript ''tor'') with high Mach numbers are generally measured in NBI-heated plasmas (since the neutral beams aim in the co-plasma current direction). They are considerably lower with only ICRH (and Ohmic) heating, but still surprisingly large considering that ICRH appears to inject relatively small amounts of angular momentum. Either the applied torques are larger than naively expected, or the anomalous transport of angular momentum is smaller than expected. Since ICRH is one of the main candidates for heating next-step tokamaks, and for creating burning plasmas in future tokamak reactors, this paper attempts to understand ICRH-induced plasma rotation.
Date: June 27, 2001
Creator: Budny, R. V.; Chang, C. S.; Giroud, C.; Goldston, R. J.; McCune, D.; Ongena, J. et al.
Object Type: Report
System: The UNT Digital Library
A complete analytic inversion of supernova lines in the Sobolevapproximation (open access)

A complete analytic inversion of supernova lines in the Sobolevapproximation

We show that the shape of P-Cygni line profiles of photospheric phase supernova can be analytically inverted to extract both the optical depth and source function of the line -- i.e. all the physical content of the model for the case when the Sobolev approximation is valid. Under various simplifying assumptions, we derive formulae that give S(r) and {tau}(r) in terms of derivatives of the line flux with respect to wavelength. The transition region between the minimum and maximum of the line profile turns out to give especially interesting information on the optical depth near the photosphere. The formulae give insights into the relationship between line shape and physical quantities that may be useful in interpreting observed spectra and detailed numerical calculations.
Date: September 27, 2001
Creator: Kasen, Daniel; Branch, David; Baron, E. & Jeffery, David
Object Type: Article
System: The UNT Digital Library
Concentrating Solar Power: Energy from Mirrors (open access)

Concentrating Solar Power: Energy from Mirrors

This fact sheet explains how concentrating solar power technology works and the three types of systems in development today: trough, dish, and central receiver.
Date: February 27, 2001
Creator: Poole, L.
Object Type: Book
System: The UNT Digital Library
Cooperative Research in C1 Chemistry (open access)

Cooperative Research in C1 Chemistry

None
Date: October 27, 2001
Creator: Huffman, Gerald P.
Object Type: Report
System: The UNT Digital Library
Corrective Action Investigation Plan for Corrective Action Unit 34: Area 3 Contaminated Waste Site, Nevada Test Site, Nevada (Rev. 0, March 2001) (open access)

Corrective Action Investigation Plan for Corrective Action Unit 34: Area 3 Contaminated Waste Site, Nevada Test Site, Nevada (Rev. 0, March 2001)

This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 34 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 34 consists of four Corrective Action Sites (CASs). The CAU is located within the Area 3 Compound at the Nevada Test Site (NTS) in the vicinity of the Mud Plant Facility in Yucca Valley. Historically, CAS 03-09-07, Mud Pit, was used for disposal of excess mud from washing drilling equipment from 1968 to 1974, at which time it began to be used for excess mud disposal (currently inactive); CAS 03-44-01, Chromium Contamination Spill, was used to store additives used in the formulation of drilling mud from the early 1960s to the mid-1990s; CAS 03-47-02, Area 3 Mud Plant Pond, was used as a freshwater storage reservoir for the mud plant as well as supplied water for a number of activities including the mixing of mud, the rinsing and cleaning of tanks, and various washdowns from the 1960s through 1990s; and CAS 03-09-06, Mud Disposal Crater, was created in 1962 by …
Date: March 27, 2001
Creator: United States. National Nuclear Security Administration. Nevada Operations Office.
Object Type: Report
System: The UNT Digital Library
Critical infrastructure assurance guidelines for municipal governments : planning for electric power disruptions. (open access)

Critical infrastructure assurance guidelines for municipal governments : planning for electric power disruptions.

The economic prosperity and the well-being of our nation's communities depend on the reliable functioning of critical infrastructures: transportation, banking and finance, information and communications, water supply systems, emergency services, and especially energy (electric power, oil, and natural gas). In the new economy, these infrastructures are increasingly reliant on information technologies and are strongly affected by restructuring and other market forces. They are much more heavily interconnected than ever before, and disruptions in one system can have significant adverse consequences, both locally and regionally. Communities often are not well prepared to deal with widespread infrastructure failures, which could become commonplace in the new millennium. This report, prepared on behalf of the partnership, is a first-of-a-kind effort to compile this type of information on the electric power system in a form that municipal governments can use and adapt to local conditions. ComEd and Harza Engineering Company have provided valuable support for this effort. Argonne National Laboratory's Infrastructure Assurance Center compiled and integrated the planning information.
Date: March 27, 2001
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Denuded Zones, Diffusional Creep, and Grain Boundary Sliding (open access)

Denuded Zones, Diffusional Creep, and Grain Boundary Sliding

The appearance of denuded zones following low stress creep in particle-containing crystalline materials is both a microstructural prediction and observation often cited as irrefutable evidence for the Nabarro-Herring mechanism of diffusional creep. The denuded zones are predicted to be at grain boundaries that are orthogonal to the direction of the applied stress. Furthermore, their dimensions should account for the accumulated plastic flow. In the present paper, the evidence for such denuded zones is critically examined. These zones have been observed during creep of magnesium, aluminum, and nickel-base alloys. The investigation casts serious doubts on the apparently compelling evidence for the link between denuded zones and diffusional creep. Specifically, denuded zones are clearly observed under conditions that are explicitly not diffusional creep. Additionally, the denuded zones are often found in directions that are not orthogonal to the applied stress. Other mechanisms that can account for the observations of denuded zones are discussed. It is proposed that grain boundary sliding accommodated by slip is the rate-controlling process in the stress range where denuded zones have been observed. It is likely that the denuded zones are created by dissolution of precipitates at grain boundaries that are simultaneously sliding and migrating during creep.
Date: June 27, 2001
Creator: Wadsworth, J; Ruano, O A & Sherby, O D
Object Type: Article
System: The UNT Digital Library
DESCRIPTION OF THE RHIC SEQUENCER SYSTEM. (open access)

DESCRIPTION OF THE RHIC SEQUENCER SYSTEM.

The movement of the Relativistic Heavy Ion Collider (RHIC) through its various states (eg. injection, acceleration, storage, collisions) is controlled by an application called the Sequencer. This program orchestrates most magnet and instrumentation systems and is responsible for the coordinated acquisition and saving of data from various systems. The Sequencer system, its software infrastructure, support programs, and the language used to drive it are discussed in this paper. Initial operational experience is also described.
Date: November 27, 2001
Creator: Dottavio, T.; Frak, B.; Morris, J.; Satogata, T. & van Zeijts, J.
Object Type: Article
System: The UNT Digital Library
Detecting Translation Errors in CAD Surfaces and Preparing Geometries for Mesh Generation (open access)

Detecting Translation Errors in CAD Surfaces and Preparing Geometries for Mesh Generation

The authors have developed tools for the efficient preparation of CAD geometries for mesh generation. Geometries are read from IGES files and then maintained in a boundary-representation consisting of a patchwork of trimmed and untrimmed surfaces. Gross errors in the geometry can be identified and removed automatically while a user interface is provided for manipulating the geometry (such as correcting invalid trimming curves or removing unwanted details). Modifying the geometry by adding or deleting surfaces and/or sectioning it by arbitrary planes (e.g. symmetry planes) is also supported. These tools are used for robust and accurate geometry models for initial mesh generation and will be applied to in situ mesh generation requirements of moving and adaptive grid simulations.
Date: August 27, 2001
Creator: Petersson, N Anders & Chand, K K
Object Type: Article
System: The UNT Digital Library
Development and Evaluation of Rhenium-188-labeled Radioactive Stents for Restenosis Therapy and Development of Strategies for Radiolabeling Brachytherapy Sources with Palladium-103 (open access)

Development and Evaluation of Rhenium-188-labeled Radioactive Stents for Restenosis Therapy and Development of Strategies for Radiolabeling Brachytherapy Sources with Palladium-103

This project involved collaboration between InnerDyne, Inc., and radiopharmaceutical research programs at the Oak Ridge National Laboratory (ORNL) and Brookhaven National Laboratory (BNL) which explored new strategies for the development and animal testing of radioactive rhenium-188-labeled implantable stent sources for the treatment of coronary restenosis after angioplasty and the development of chemical species radiolabeled with the palladium-103 radioisotope for the treatment of cancer. Rhenium-188 was made available for these studies from radioactive decay of tungsten-188 produced in the ORNL High Flux Isotope Reactor (HFIR). Stent activation and coating technology was developed and provided by InnerDyne, Inc., and stent radiolabeling technology and animal studies were conducted by InnerDyne staff in conjunction with investigators at BNL. Collaborative studies in animals were supported at sites by InnerDyne, Inc. New chemical methods for attaching the palladium-103 radioisotope to bifunctional chelate technologies were developed by investigators at ORNL.
Date: April 27, 2001
Creator: Knapp, F.F.
Object Type: Report
System: The UNT Digital Library
The Development of Layered Photonic Band Gap Structures Using a Micro-Transfer Molding Technique (open access)

The Development of Layered Photonic Band Gap Structures Using a Micro-Transfer Molding Technique

Over the last ten years, photonic band gap (PBG) theory and technology have become an important area of research because of the numerous possible applications ranging from high-efficiency laser diodes to optical circuitry. This research concentrates on reducing the length scale in the fabrication of layered photonic band gap structures and developing procedures to improve processing consistency. Various procedures and materials have been used in the fabrication of layered PBG structures. This research focused on an economical micro transfer molding approach to create the final PBG structure. A poly dimethylsiloxane (PDMS) rubber mold was created from a silicon substrate. It was filled with epoxy and built layer-by-layer to create a 3-D epoxy structure. This structure was infiltrated with nanoparticle titania or a titania sol-gel, then fired to remove the polymer mold, leaving a monolithic ceramic inverse of the epoxy structure. The final result was a lattice of titania rolds that resembles a face-centered tetragonal structure. The original intent of this research was to miniaturize this process to a bar size small enough to create a photonic band gap for wavelengths of visible electro-magnetic radiation. The factor limiting progress was the absence of a silicon master mold of small enough dimensions. …
Date: June 27, 2001
Creator: Sutherland, Kevin Jerome
Object Type: Thesis or Dissertation
System: The UNT Digital Library
EBS Radionuclide Transport Abstraction (open access)

EBS Radionuclide Transport Abstraction

The purpose of this work is to develop the Engineered Barrier System (EBS) radionuclide transport abstraction model, as directed by a written development plan (CRWMS M&O 1999a). This abstraction is the conceptual model that will be used to determine the rate of release of radionuclides from the EBS to the unsaturated zone (UZ) in the total system performance assessment-license application (TSPA-LA). In particular, this model will be used to quantify the time-dependent radionuclide releases from a failed waste package (WP) and their subsequent transport through the EBS to the emplacement drift wall/UZ interface. The development of this conceptual model will allow Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department to provide a more detailed and complete EBS flow and transport abstraction. The results from this conceptual model will allow PA0 to address portions of the key technical issues (KTIs) presented in three NRC Issue Resolution Status Reports (IRSRs): (1) the Evolution of the Near-Field Environment (ENFE), Revision 2 (NRC 1999a), (2) the Container Life and Source Term (CLST), Revision 2 (NRC 1999b), and (3) the Thermal Effects on Flow (TEF), Revision 1 (NRC 1998). The conceptual model for flow and transport in the EBS will be referred to …
Date: June 27, 2001
Creator: Schreiner, R.
Object Type: Report
System: The UNT Digital Library
Effect of Boronization on Ohmic Plasmas in NSTX (open access)

Effect of Boronization on Ohmic Plasmas in NSTX

Boronization of the National Spherical Torus Experiment (NSTX) has enabled access to higher density, higher confinement plasmas. A glow discharge with 4 mTorr helium and 10% deuterated trimethyl boron deposited 1.7 g of boron on the plasma facing surfaces. Ion beam analysis of witness coupons showed a B+C areal density of 10 to the 18 (B+C) cm to the -2 corresponding to a film thickness of 100 nm. Subsequent ohmic discharges showed oxygen emission lines reduced by x15, carbon emission reduced by two and copper reduced to undetectable levels. After boronization, the plasma current flattop time increased by 70% enabling access to higher density, higher confinement plasmas.
Date: March 27, 2001
Creator: Skinner, C. H.; Kugel, H.; Maingi, R.; Wampler, W. R.; Blanchard, W.; Bell, M. et al.
Object Type: Report
System: The UNT Digital Library