A 4.2 GS/sec. Synchronized Vertical Excitation System for SPS Studies - Steps Toward Wideband Feedback (open access)

A 4.2 GS/sec. Synchronized Vertical Excitation System for SPS Studies - Steps Toward Wideband Feedback

A 4.2 GS/sec. beam excitation system with accelerator synchronization and power stages is described. The system is capable of playing unique samples (32 samples/bunch) for 15,000 turns on selected bunch(es) in the SPS in syn- chronism with the injection and acceleration cycle. The purpose of the system is to excite internal modes of single-bunch vertical motion, and study the bunch dynamics in the presence of developing Electron cloud or TMCI effects. The system includes a synchronized master oscillator, SPS timing functions, an FPGA based arbitrary waveform generator, 4.2 GS/sec. D/A system and four 80W 20-1000 MHz amplifiers driving a tapered stripline pickup/kicker. A software GUI allows specification of various modulation signals, selection of bunches and turns to excite, while a remote control interface allows simple control/monitoring of the RF power stages located in the tunnel. The successful use of this system for SPS MD measurements in 2011 is a vital proof-of-principle for wideband feedback using similar functions to correct the beam motion.
Date: July 10, 2012
Creator: Fox, John
Object Type: Article
System: The UNT Digital Library
2012 ELECTRON DONOR-ACCEPTOR INTERACTIONS GORDON RESEARCH CONFERENCE, AUGUST 5-10, 2012 (open access)

2012 ELECTRON DONOR-ACCEPTOR INTERACTIONS GORDON RESEARCH CONFERENCE, AUGUST 5-10, 2012

The upcoming incarnation of the Gordon Research Conference on Electron Donor Acceptor Interactions will feature sessions on classic topics including proton-coupled electron transfer, dye-sensitized solar cells, and biological electron transfer, as well as emerging areas such as quantum coherence effects in donor-acceptor interactions, spintronics, and the application of donor-acceptor interactions in chemical synthesis.
Date: August 10, 2012
Creator: McCusker, James
Object Type: Article
System: The UNT Digital Library
2012 Molecular Basis of Microbial One-Carbon Metabolism Gordon Research Conferences and Gordon Research Seminar, August 4-10,2012 (open access)

2012 Molecular Basis of Microbial One-Carbon Metabolism Gordon Research Conferences and Gordon Research Seminar, August 4-10,2012

The 2012 Gordon Conference will present and discuss cutting-edge research in the field of microbial metabolism of C1 compounds. The conference will feature the roles and application of C1 metabolism in natural and synthetic systems at scales from molecules to ecosystems. The conference will stress molecular aspects of the unique metabolism exhibited by autotrophic bacteria, methanogens, methylotrophs, aerobic and anaerobic methanotrophs, and acetogens.
Date: August 10, 2012
Creator: Hanson, Thomas
Object Type: Article
System: The UNT Digital Library
2012 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies (open access)

2012 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

This Research is about Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies which presents a preliminary model of the three-dimensional seismic structure of the Iran region.
Date: September 10, 2012
Creator: Wetovsky, Marvin A.; Anderson, Dale; Arrowsmith, Stephen J.; Begnaud, Michael L.; Hartse, Hans E.; Maceira, Monica et al.
Object Type: Article
System: The UNT Digital Library
2012 PLANT CELL WALLS GORDON RESEARCH CONFERENCE AND GORDON RESEARCH SEMINAR, AUGUST 4-10, 2012 (open access)

2012 PLANT CELL WALLS GORDON RESEARCH CONFERENCE AND GORDON RESEARCH SEMINAR, AUGUST 4-10, 2012

The sub-theme of this year’s meeting, ‘Cell Wall Research in a Post-Genome World’, will be a consideration of the dramatic technological changes that have occurred in the three years since the previous cell wall Gordon Conference in the area of DNA sequencing. New technologies are providing additional perspectives of plant cell wall biology across a rapidly growing number of species, highlighting a myriad of architectures, compositions, and functions in both "conventional" and specialized cell walls. This meeting will focus on addressing the knowledge gaps and technical challenges raised by such diversity, as well as our need to understand the underlying processes for critical applications such as crop improvement and bioenergy resource development.
Date: August 10, 2012
Creator: Rose, Jocelyn
Object Type: Article
System: The UNT Digital Library
2012 VIBRATIONAL SPECTROSCOPY GORDON RESEARCH CONFERENCE, AUGUST 5-10, 2012 (open access)

2012 VIBRATIONAL SPECTROSCOPY GORDON RESEARCH CONFERENCE, AUGUST 5-10, 2012

The Vibrational Spectroscopy conference brings together experimentalists and theoreticians working at the frontiers of modern vibrational spectroscopy, with a special emphasis on spectroscopies that probe the structure and dynamics of molecules in gases, liquids, and at interfaces. The conference explores the wide range of state-of-the-art techniques based on vibrational motion. These techniques span the fields of time-domain, high-resolution frequency-domain, spatially-resolved, nonlinear, and multidimensional spectroscopies. The conference highlights both the application of these techniques in chemistry, materials, biology, the environment, and medicine as well as the development of theoretical models that enable one to connect spectroscopic signatures to underlying molecular motions including chemical reaction dynamics. The conference goal is to advance the field of vibrational spectroscopy by bringing together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of molecular systems ranging from small polyatomic molecules to large biomolecules, nanomaterials, and environmental systems.
Date: August 10, 2012
Creator: Geiger, Franz
Object Type: Article
System: The UNT Digital Library
Accelerating a random forest classifier: multi-core, GP-GPU, or FPGA? (open access)

Accelerating a random forest classifier: multi-core, GP-GPU, or FPGA?

None
Date: January 10, 2012
Creator: Van Essen, B. C.; Macaraeg, C. C.; Prenger, R. & Gokhale, M.
Object Type: Article
System: The UNT Digital Library
Accelerating Atomic Orbital-based Electronic Structure Calculation via Pole Expansion plus Selected Inversion (open access)

Accelerating Atomic Orbital-based Electronic Structure Calculation via Pole Expansion plus Selected Inversion

We describe how to apply the recently developed pole expansion plus selected inversion (PEpSI) technique to Kohn-Sham density function theory (DFT) electronic structure calculations that are based on atomic orbital discretization. We give analytic expressions for evaluating charge density, total energy, Helmholtz free energy and atomic forces without using the eigenvalues and eigenvectors of the Kohn-Sham Hamiltonian. We also show how to update the chemical potential without using Kohn-Sham eigenvalues. The advantage of using PEpSI is that it has a much lower computational complexity than that associated with the matrix diagonalization procedure. We demonstrate the performance gain by comparing the timing of PEpSI with that of diagonalization on insulating and metallic nanotubes. For these quasi-1D systems, the complexity of PEpSI is linear with respect to the number of atoms. This linear scaling can be observed in our computational experiments when the number of atoms in a nanotube is larger than a few hundreds. Both the wall clock time and the memory requirement of PEpSI is modest. This makes it even possible to perform Kohn-Sham DFT calculations for 10,000-atom nanotubes on a single processor. We also show that the use of PEpSI does not lead to loss of accuracy required in …
Date: February 10, 2012
Creator: Lin, Lin; Chen, Mohan; Yang, Chao & He, Lixin
Object Type: Article
System: The UNT Digital Library
ACTUAL-WASTE TESTING OF ULTRAVIOLET LIGHT TO AUGMENT THE ENHANCED CHEMICAL CLEANING OF SRS SLUDGE (open access)

ACTUAL-WASTE TESTING OF ULTRAVIOLET LIGHT TO AUGMENT THE ENHANCED CHEMICAL CLEANING OF SRS SLUDGE

In support of Savannah River Site (SRS) tank closure efforts, the Savannah River National Laboratory (SRNL) conducted Real Waste Testing (RWT) to evaluate Enhanced Chemical Cleaning (ECC), an alternative to the baseline 8 wt% oxalic acid (OA) chemical cleaning technology for tank sludge heel removal. ECC utilizes a more dilute OA solution (2 wt%) and an oxalate destruction technology using ozonolysis with or without the application of ultraviolet (UV) light. SRNL conducted tests of the ECC process using actual SRS waste material from Tanks 5F and 12H. The previous phase of testing involved testing of all phases of the ECC process (sludge dissolution, OA decomposition, product evaporation, and deposition tank storage) but did not involve the use of UV light in OA decomposition. The new phase of testing documented in this report focused on the use of UV light to assist OA decomposition, but involved only the OA decomposition and deposition tank portions of the process. Compared with the previous testing at analogous conditions without UV light, OA decomposition with the use of UV light generally reduced time required to reach the target of <100 mg/L oxalate. This effect was the most pronounced during the initial part of the decomposition …
Date: July 10, 2012
Creator: Martino, C.; King, W. & Ketusky, E.
Object Type: Report
System: The UNT Digital Library
Advances in NIF Shock Timing Experiments (open access)

Advances in NIF Shock Timing Experiments

None
Date: July 10, 2012
Creator: Robey, H. F.; Celliers, P. M.; Moody, J. D. & MacKinnon, A. J.
Object Type: Article
System: The UNT Digital Library
Analysis of ultra-narrow ferromagnetic domain walls (open access)

Analysis of ultra-narrow ferromagnetic domain walls

New materials with high magnetic anisotropy will have domains separated by ultra-narrow ferromagnetic walls with widths on the order of a few unit cells, approaching the limit where the elastic continuum approximation often used in micromagnetic simulations is accurate. The limits of this approximation are explored, and the static and dynamic interactions with intrinsic crystalline defects and external driving #12;elds are modeled. The results developed here will be important when considering the stability of ultra-high-density storage media.
Date: January 10, 2012
Creator: Jenkins, Catherine & Paul, David
Object Type: Article
System: The UNT Digital Library
Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report July 1–September 30, 2012 (open access)

Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report July 1–September 30, 2012

Individual datastreams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile research sites are collected and routed to the Data Management Facility (DMF) for processing in near-real-time. Instrument and processed data are then delivered approximately daily to the ARM Data Archive, where they are made freely available to the research community. For each instrument, we calculate the ratio of the actual number of processed data records received daily at the Data Archive to the expected number of data records. The results are tabulated by (1) individual datastream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998.
Date: October 10, 2012
Creator: Voyles, JW
Object Type: Text
System: The UNT Digital Library
BENEFITS OF VIBRATION ANALYSIS FOR DEVELOPMENT OF EQUIPMENT IN HLW TANKS - 12341 (open access)

BENEFITS OF VIBRATION ANALYSIS FOR DEVELOPMENT OF EQUIPMENT IN HLW TANKS - 12341

Vibration analyses of equipment intended for use in the Savannah River Site (SRS) radioactive liquid waste storage tanks are performed during pre-deployment testing and has been demonstrated to be effective in reducing the life-cycle costs of the equipment. Benefits of using vibration analysis to identify rotating machinery problems prior to deployment in radioactive service will be presented in this paper. Problems encountered at SRS and actions to correct or lessen the severity of the problem are discussed. In short, multi-million dollar cost saving have been realized at SRS as a direct result of vibration analysis on existing equipment. Vibration analysis of equipment prior to installation can potentially reduce inservice failures, and increases reliability. High-level radioactive waste is currently stored in underground carbon steel waste tanks at the United States Department of Energy (DOE) Savannah River Site and at the Hanford Site, WA. Various types of rotating machinery (pumps and separations equipment) are used to manage and retrieve the tank contents. Installation, maintenance, and repair of these pumps and other equipment are expensive. In fact, costs to remove and replace a single pump can be as high as a half million dollars due to requirements for radioactive containment. Problems that lead …
Date: January 10, 2012
Creator: Stefanko, D. & Herbert, J.
Object Type: Article
System: The UNT Digital Library
Biofuels from Bacteria, Electricity, and CO2 (open access)

Biofuels from Bacteria, Electricity, and CO2

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Electrofuels program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses combining ammonia and bacteria to produce liquid fuel as part of the "Biofuels from CO2 Using Ammonia or Iron-Oxidizing Bacteria in Reverse Microbial Fuel Cells" project.
Date: May 10, 2012
Creator: Columbia University
Object Type: Text
System: The UNT Digital Library
Biofuels from E. coli (open access)

Biofuels from E. coli

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Electrofuels program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses the modification of E. coli to consume carbon dioxide and produce liquid fuel as part of the "Engineering E. coli as an Electrofuels Chassis for Isooctane Production" project.
Date: May 10, 2012
Creator: Ginkgo Bioworks
Object Type: Text
System: The UNT Digital Library
Biofuels from Solar Energy and Bacteria (open access)

Biofuels from Solar Energy and Bacteria

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Electrofuels program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses the conversion of carbon dioxide into liquid fuels as part of the "Electrofuels Via Direct Electron Transfer from Electrodes to Microbes" project.
Date: May 10, 2012
Creator: University of Massachusetts Amherst
Object Type: Text
System: The UNT Digital Library
BLENDING ANALYSIS FOR RADIOACTIVE SALT WASTE PROCESSING FACILITY (open access)

BLENDING ANALYSIS FOR RADIOACTIVE SALT WASTE PROCESSING FACILITY

Savannah River National Laboratory (SRNL) evaluated methods to mix and blend the contents of the blend tanks to ensure the contents are properly blended before they are transferred from the blend tank such as Tank 21 and Tank 24 to the Salt Waste Processing Facility (SWPF) feed tank. The tank contents consist of three forms: dissolved salt solution, other waste salt solutions, and sludge containing settled solids. This paper focuses on developing the computational model and estimating the operation time of submersible slurry pump when the tank contents are adequately blended prior to their transfer to the SWPF facility. A three-dimensional computational fluid dynamics approach was taken by using the full scale configuration of SRS Type-IV tank, Tank 21H. Major solid obstructions such as the tank wall boundary, the transfer pump column, and three slurry pump housings including one active and two inactive pumps were included in the mixing performance model. Basic flow pattern results predicted by the computational model were benchmarked against the SRNL test results and literature data. Tank 21 is a waste tank that is used to prepare batches of salt feed for SWPF. The salt feed must be a homogeneous solution satisfying the acceptance criterion of …
Date: May 10, 2012
Creator: Lee, S.
Object Type: Article
System: The UNT Digital Library
Blending Of Radioactive Salt Solutions In Million Gallon Tanks (open access)

Blending Of Radioactive Salt Solutions In Million Gallon Tanks

Research was completed at Savannah River National Laboratory (SRNL) to investigate processes related to the blending of radioactive, liquid waste, salt solutions in 4920 cubic meter, 25.9 meter diameter storage tanks. One process was the blending of large salt solution batches (up to 1135 ? 3028 cubic meters), using submerged centrifugal pumps. A second process was the disturbance of a settled layer of solids, or sludge, on the tank bottom. And a third investigated process was the settling rate of sludge solids if suspended into slurries by the blending pump. To investigate these processes, experiments, CFD models (computational fluid dynamics), and theory were applied. Experiments were performed using simulated, non-radioactive, salt solutions referred to as supernates, and a layer of settled solids referred to as sludge. Blending experiments were performed in a 2.44 meter diameter pilot scale tank, and flow rate measurements and settling tests were performed at both pilot scale and full scale. A summary of the research is presented here to demonstrate the adage that, ?One good experiment fixes a lot of good theory?. Experimental testing was required to benchmark CFD models, or the models would have been incorrectly used. In fact, CFD safety factors were established by …
Date: December 10, 2012
Creator: Leishear, Robert A.; Lee, Si Y.; Fowley, Mark D. & Poirier, Michael R.
Object Type: Article
System: The UNT Digital Library
A Block-Diagonal Algebraic Multigrid Preconditioner for the Brinkman Problem (open access)

A Block-Diagonal Algebraic Multigrid Preconditioner for the Brinkman Problem

None
Date: January 10, 2012
Creator: Vassilevski, P. S. & Villa, U.
Object Type: Article
System: The UNT Digital Library
Bootstrap Current for the Edge Pedestal Plasma in a Diverted Tokamak Geometry (open access)

Bootstrap Current for the Edge Pedestal Plasma in a Diverted Tokamak Geometry

The edge bootstrap current plays a critical role in the equilibrium and stability of the steep edge pedestal plasma. The pedestal plasma has an unconventional and difficult neoclassical property, as compared with the core plasma. It has a narrow passing particle region in velocity space that can be easily modified or destroyed by Coulomb collisions. At the same time, the edge pedestal plasma has steep pressure and electrostatic potential gradients whose scale-lengths are comparable with the ion banana width, and includes a magnetic separatrix surface, across which the topological properties of the magnetic field and particle orbits change abruptly. A driftkinetic particle code XGC0, equipped with a mass-momentum-energy conserving collision operator, is used to study the edge bootstrap current in a realistic diverted magnetic field geometry with a self-consistent radial electric field. When the edge electrons are in the weakly collisional banana regime, surprisingly, the present kinetic simulation confirms that the existing analytic expressions [represented by O. Sauter et al. , Phys. Plasmas 6 , 2834 (1999)] are still valid in this unconventional region, except in a thin radial layer in contact with the magnetic separatrix. The agreement arises from the dominance of the electron contribution to the bootstrap current …
Date: August 10, 2012
Creator: Koh, S.; Chang, C. S.; Ku, S.; Menard, J. E.; Weitzner, H. & Choe, W.
Object Type: Report
System: The UNT Digital Library
CEMENTITIOUS GROUT FOR CLOSING SRS HIGH LEVEL WASTE TANKS - #12315 (open access)

CEMENTITIOUS GROUT FOR CLOSING SRS HIGH LEVEL WASTE TANKS - #12315

In 1997, the first two United States Department of Energy (US DOE) high level waste tanks (Tanks 17-F and 20-F: Type IV, single shell tanks) were taken out of service (permanently closed) at the Savannah River Site (SRS). In 2012, the DOE plans to remove from service two additional Savannah River Site (SRS) Type IV high-level waste tanks, Tanks 18-F and 19-F. These tanks were constructed in the late 1950's and received low-heat waste and do not contain cooling coils. Operational closure of Tanks 18-F and 19-F is intended to be consistent with the applicable requirements of the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and will be performed in accordance with South Carolina Department of Health and Environmental Control (SCDHEC). The closure will physically stabilize two 4.92E+04 cubic meter (1.3 E+06 gallon) carbon steel tanks and isolate and stabilize any residual contaminants left in the tanks. The closure will also fill, physically stabilize and isolate ancillary equipment abandoned in the tanks. A Performance Assessment (PA) has been developed to assess the long-term fate and transport of residual contamination in the environment resulting from the operational closure of the F-Area Tank …
Date: January 10, 2012
Creator: Langton, C.; Burns, H. & Stefanko, D.
Object Type: Article
System: The UNT Digital Library
Challenges of 4th Generation Light Sources (open access)

Challenges of 4th Generation Light Sources

This report talks about Challenges of 4th Generation Light Sources
Date: December 10, 2012
Creator: Pellegrini, C.
Object Type: Article
System: The UNT Digital Library
Clic Cdr - Physics and Detectors: Clic Conceptual Design Report. (open access)

Clic Cdr - Physics and Detectors: Clic Conceptual Design Report.

This report forms part of the Conceptual Design Report (CDR) of the Compact LInear Collider (CLIC). The CLIC accelerator complex is described in a separate CDR volume. A third document, to appear later, will assess strategic scenarios for building and operating CLIC in successive center-of-mass energy stages. It is anticipated that CLIC will commence with operation at a few hundred GeV, giving access to precision standard-model physics like Higgs and top-quark physics. Then, depending on the physics landscape, CLIC operation would be staged in a few steps ultimately reaching the maximum 3 TeV center-of-mass energy. Such a scenario would maximize the physics potential of CLIC providing new physics discovery potential over a wide range of energies and the ability to make precision measurements of possible new states previously discovered at the Large Hadron Collider (LHC). The main purpose of this document is to address the physics potential of a future multi-TeV e{sup +}e{sup -} collider based on CLIC technology and to describe the essential features of a detector that are required to deliver the full physics potential of this machine. The experimental conditions at CLIC are significantly more challenging than those at previous electron-positron colliders due to the much higher …
Date: February 10, 2012
Creator: Berger, E.; Demarteau, M.; Repond, J.; Xia, L. & Weerts, H.
Object Type: Report
System: The UNT Digital Library
CODIFICATION OF FIBER REINFORCED COMPOSITE PIPING (open access)

CODIFICATION OF FIBER REINFORCED COMPOSITE PIPING

The goal of the overall project is to successfully adapt spoolable FRP currently used in the oil industry for use in hydrogen pipelines. The use of FRP materials for hydrogen service will rely on the demonstrated compatibility of these materials for pipeline service environments and operating conditions. The ability of the polymer piping to withstand degradation while in service, and development of the tools and data required for life management are imperative for successful implementation of these materials for hydrogen pipeline. The information and data provided in this report provides the technical basis for the codification for fiber reinforced piping (FRP) for hydrogen service. The DOE has invested in the evaluation of FRP for the delivery for gaseous hydrogen to support the development of a hydrogen infrastructure. The codification plan calls for detailed investigation of the following areas: System design and applicable codes and standards; Service degradation of FRP; Flaw tolerance and flaw detection; Integrity management plan; Leak detection and operational controls evaluation; Repair evaluation. The FRP codification process started with commercially available products that had extensive use in the oil and gas industry. These products have been evaluated to assure that sufficient structural integrity is available for a gaseous …
Date: October 10, 2012
Creator: Rawls, G.
Object Type: Report
System: The UNT Digital Library