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
17 GHz High Gradient Accelerator Research (open access)

17 GHz High Gradient Accelerator Research

This is a report on the MIT High Gradient Accelerator Research program which has included: Operation of the 17 GHz, 25 MeV MIT/Haimson Research Corp. electron accelerator at MIT, the highest frequency, stand-alone accelerator in the world; collaboration with members of the US High Gradient Collaboration, including the design and test of novel structures at SLAC at 11.4 GHz; the design, construction and testing of photonic bandgap structures, including metallic and dielectric structures; the investigation of the wakefields in novel structures; and the training of the next generation of graduate students and postdoctoral associates in accelerator physics.
Date: July 10, 2013
Creator: Temkin, Richard J. & Shapiro, Michael A.
Object Type: Report
System: The UNT Digital Library
25 Year Lifetime for Flexible Buildings Integrated Photovoltaics (open access)

25 Year Lifetime for Flexible Buildings Integrated Photovoltaics

Although preliminary proof-of-principle of the efficacy of barrier materials and processes, first developed by Battelle at PNNL and commercialized by Vitex, has been demonstrated at the laboratory scale, there are several challenges to the practical commercial implementation of these developments in the Buildings Integrated Photovoltaics (BIPV) market. Two important issues that are addressed in this project are identifying a low cost substrate material that can survive in the outside environment (rain, heat, dust, hail, etc.) for 25 years and developing an encapsulation method for the photovoltaic (PV) cells that can meet the required barrier performance without driving the cost of the total barrier package out of range (remaining below $3.00/Wp). Without these solutions, current encapsulation technologies will limit the use of PV for BIPV applications. Flexible, light-weight packaging that can withstand 25 years in the field is required for a totally flexible integrated PV package. The benefit of this research is to make substantial progress in the development of a cost-effective, viable thin film barrier package which will be a critical enabling technology to meet the Solar America Initiative cost and device reliability goals, and to make photovoltaics (PV) more cost-competitive with electricity generated using fossil fuels. Increased PV installations …
Date: July 10, 2010
Creator: Gross, Mark E.
Object Type: Report
System: The UNT Digital Library
317/319 Phytoremediation site monitoring report - 2009 growing season : final report. (open access)

317/319 Phytoremediation site monitoring report - 2009 growing season : final report.

In 1999, Argonne National Laboratory (Argonne) designed and installed a series of engineered plantings consisting of a vegetative cover system and approximately 800 hybrid poplars and willows rooting at various predetermined depths. The plants were installed using various methods including Applied Natural Science's TreeWell{reg_sign} system. The goal of the installation was to protect downgradient surface and groundwater by intercepting the contaminated groundwater with the tree roots, removing moisture from the upgradient soil area, reducing water infiltration, preventing soil erosion, degrading and/or transpiring the residual volatile organic compounds (VOCs), and removing tritium from the subsoil and groundwater. This report presents the results of the monitoring activities conducted by Argonne's Energy Systems (ES) Division in the growing season of 2009. Monitoring of the planted trees began soon after the trees were installed in 1999 and has been conducted every summer since then. As the trees grew and consolidated their growth into the contaminated soil and groundwater, their exposure to the contaminants was progressively shown through tissue sampling. During the 2009 sampling campaign, VOC concentrations found in the French Drain area were in general consistent with or slightly lower than the 2008 results. Additionally, closely repeated, stand wide analyses showed contaminant fluctuations that …
Date: February 10, 2010
Creator: Negri, C .N.; Benda, P. L.; Gopalakrishnan, G. & Systems, Energy
Object Type: Report
System: The UNT Digital Library
2007 Estimated International Energy Flows (open access)

2007 Estimated International Energy Flows

An energy flow chart or 'atlas' for 136 countries has been constructed from data maintained by the International Energy Agency (IEA) and estimates of energy use patterns for the year 2007. Approximately 490 exajoules (460 quadrillion BTU) of primary energy are used in aggregate by these countries each year. While the basic structure of the energy system is consistent from country to country, patterns of resource use and consumption vary. Energy can be visualized as it flows from resources (i.e. coal, petroleum, natural gas) through transformations such as electricity generation to end uses (i.e. residential, commercial, industrial, transportation). These flow patterns are visualized in this atlas of 136 country-level energy flow charts.
Date: March 10, 2011
Creator: Smith, C. A.; Belles, R. D. & Simon, A. J.
Object Type: Report
System: The UNT Digital Library
2010 Diffraction Methods in Structural Biology (open access)

2010 Diffraction Methods in Structural Biology

Advances in basic methodologies have played a major role in the dramatic progress in macromolecular crystallography over the past decade, both in terms of overall productivity and in the increasing complexity of the systems being successfully tackled. The 2010 Gordon Research Conference on Diffraction Methods in Structural Biology will, as in the past, focus on the most recent developments in methodology, covering all aspects of the process from crystallization to model building and refinement, complemented by examples of structural highlights and complementary methods. Extensive discussion will be encouraged and it is hoped that all attendees will participate by giving oral or poster presentations, the latter using the excellent poster display area available at Bates College. The relatively small size and informal atmosphere of the meeting provides an excellent opportunity for all participants, especially younger scientists, to meet and exchange ideas with leading methods developers.
Date: March 10, 2011
Creator: Gonzalez, Ana
Object Type: Article
System: The UNT Digital Library
2011 Superconductivity Gordon Research Conference (June 5-10, 2011, Waterville Valley Resort, Waterville Valley, New Hampshire) (open access)

2011 Superconductivity Gordon Research Conference (June 5-10, 2011, Waterville Valley Resort, Waterville Valley, New Hampshire)

The 2011 Gordon Research Conference on Superconductivity will commemorate the 100th anniversary of the discovery of superconductivity by providing a forum for discussion of the latest experimental and theoretical advances in this field. The conference will bring together experts to address the current challenges in understanding correlated superconductors - from cuprates and pnictides to heavy fermion superconductors. The fundamental mechanisms of superconducting pairing, the underlying explanations for thermodynamic phase diagrams including potential importance of competing phases, the correspondence between these phenomena, and the transport and spectroscopic properties of these materials will be among the themes of the conference. We will also discuss the feasibility of using lessons learned from the study of known superconductors as a guide to the future discovery of novel and higher temperature superconductors. Speakers will be strongly encouraged to present new, unpublished work, which will ensure that discussions evoke and explore new research directions. The participation of young scientists at the graduate student or post-doctoral level will be encouraged by the offering of selected presentations, focused discussions with invited speakers, and poster sessions. In addition, the organizers have earmarked funds to facilitate attendance of members of groups underrepresented in science and engineering.
Date: June 10, 2011
Creator: Yazdani, Ali
Object Type: Article
System: The UNT Digital Library
2012 Annual Site Environmental Report (open access)

2012 Annual Site Environmental Report

N/A
Date: January 10, 2013
Creator: M., Ratel K.; Pohlot, P.; Lee, R.; Williams, J.; Remien, J.; Green, T. et al.
Object Type: Report
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
4w Thomson Scattering Probe for High-density Measurements at Titan (open access)

4w Thomson Scattering Probe for High-density Measurements at Titan

None
Date: May 10, 2010
Creator: Ross, J. S.; Kline, J. L.; Yang, S.; Henesian, M.; Weiland, T.; Price, D. et al.
Object Type: Article
System: The UNT Digital Library
6D cooling in periodic lattices including a planar snake (open access)

6D cooling in periodic lattices including a planar snake

N/A
Date: June 10, 2013
Creator: B., Palmer R.; Berg, J. S. & Stratakis, D,
Object Type: Article
System: The UNT Digital Library
Ab initio Based Modeling of Radiation Effects in Multi-Component Alloys:  Final Scientific/Technical Report (open access)

Ab initio Based Modeling of Radiation Effects in Multi-Component Alloys: Final Scientific/Technical Report

The project began March 13, 2006, allocated for three years, and received a one year extension from March 13, 2009 to March 12, 2010. It has now completed 48 of 48 total months. The project was focused on using ab initio methods to gain insights into radiation induced segregation (RIS) in Ni-Fe-Cr alloys. The project had the following key accomplishments • Development of a large database of ab initio energetics that can be used by many researchers in the future for increased understanding of this system. For example, we have the first calculations showing a dramatic stabilization effect of Cr-Cr interstitial dumbbells in Ni. • Prediction of both vacancy and interstitial diffusion constants for Ni-Cr and Ni-Fe for dilute Cr and Fe. This work included generalization of widely used multifrequency models to make use of ab initio derived energetics and thermodynamics. • Prediction of qualitative trends of RIS from vacancy and interstitial mechanisms, suggesting the two types of defect fluxes drive Cr RIS in opposite directions. • Detailed kinetic Monte Carlo modeling of diffusion by vacancy mechanism in Ni-Cr as a function of Cr concentration. The results demonstrate that Cr content can have a significant effect on RIS. • Development …
Date: June 10, 2010
Creator: Morgan, Dane
Object Type: Report
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
ACETYL-COA CLEAVAGE AND SYNTHESIS IN METHANOGENS; CHARACTERIZATION OF SUBOMPONENT INTERACTIONS IN THE ACETYL-COA DECARBONYLASE/SYNTHASE MULTIENZYME COMPLEX (open access)

ACETYL-COA CLEAVAGE AND SYNTHESIS IN METHANOGENS; CHARACTERIZATION OF SUBOMPONENT INTERACTIONS IN THE ACETYL-COA DECARBONYLASE/SYNTHASE MULTIENZYME COMPLEX

The work reported resulted in much new insight into unusual mechanisms of metalloenzymes involved in anaerobic metabolism in methanogens, other archaea, and bacteria.
Date: October 10, 2013
Creator: GRAHAM, DAVID A.
Object Type: Report
System: The UNT Digital Library
Actinic characterization of EUV bump-type phase defects (open access)

Actinic characterization of EUV bump-type phase defects

Despite tremendous progress and learning with EUV lithography, quantitative experimental information about the severity of point-like phase defects remains in short supply. We present a study of measured, EUV aerial images from a series of well-characterized, open-field, bump-type programmed phase defects, created on a substrate before multilayer deposition.
Date: January 10, 2011
Creator: Goldberg, Kenneth A.; Mochi, Iacopo & Liang, Ted
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
Adaptive AMG with Coarsening Based on Compatible Weighted Matching (open access)

Adaptive AMG with Coarsening Based on Compatible Weighted Matching

None
Date: January 10, 2013
Creator: D'Ambra, P & Vassilevski, P S
Object Type: Report
System: The UNT Digital Library
Advances in coherent electron cooling (open access)

Advances in coherent electron cooling

N/A
Date: June 10, 2013
Creator: N., Litvinenko V.
Object Type: Article
System: The UNT Digital Library
Advances in Modeling Exploding Bridgewire Initiation (open access)

Advances in Modeling Exploding Bridgewire Initiation

There is great interest in applying magnetohydrodynamic (MHD) simulation techniques to the designs of electrical high explosive (HE) initiators, for the purpose of better understanding a design's sensitivities, optimizing its performance, and/or predicting its useful lifetime. Two MHD-capable LLNL codes, CALE and ALE3D, are being used to simulate the process of ohmic heating, vaporization, and plasma formation in exploding bridgewires (EBW). Initiation of the HE is simulated using Ignition & Growth reactive flow models. 1-D, 2-D and 3-D models have been constructed and studied. The models provide some intuitive explanation of the initiation process and are useful for evaluating the potential impact of identified aging mechanisms (such as the growth of intermetallic compounds or powder sintering). The end product of this work is a simulation capability for evaluating margin in proposed, modified or aged initiation system designs.
Date: March 10, 2010
Creator: Hrousis, C A & Christensen, J S
Object Type: Article
System: The UNT Digital Library