Slowly Varying Dilaton Cosmologies and Their Field Theory Duals (open access)

Slowly Varying Dilaton Cosmologies and Their Field Theory Duals

We consider a deformation of the AdS{sub 5} x S{sup 5} solution of IIB supergravity obtained by taking the boundary value of the dilaton to be time dependent. The time dependence is taken to be slowly varying on the AdS scale thereby introducing a small parameter {epsilon}. The boundary dilaton has a profile which asymptotes to a constant in the far past and future and attains a minimum value at intermediate times. We construct the sugra solution to first non-trivial order in {epsilon}, and find that it is smooth, horizon free, and asymptotically AdS{sub 5} x S{sup 5} in the far future. When the intermediate values of the dilaton becomes small enough the curvature becomes of order the string scale and the sugra approximation breaks down. The resulting dynamics is analysed in the dual SU(N) gauge theory on S{sup 3} with a time dependent coupling constant which varies slowly. When N{epsilon} << 1, we find that a quantum adiabatic approximation is applicable, and use it to argue that at late times the geometry becomes smooth AdS{sub 5} x S{sup 5} again. When N{epsilon} >> 1, we formulate a classical adiabatic perturbation theory based on coherent states which arises in the …
Date: June 28, 2011
Creator: Awad, Adel; Das, Sumit R.; Ghosh, Archisman; Oh, Jae-Hyuk & Trivedi, Sandip P.
Object Type: Article
System: The UNT Digital Library
Stable Non-Supersymmetric Throats in String Theory (open access)

Stable Non-Supersymmetric Throats in String Theory

We construct a large class of non-supersymmetric AdS-like throat geometries in string theory by taking non-supersymmetric orbifolds of supersymmetric backgrounds. The scale of SUSY breaking is the AdS radius, and the dual field theory has explicitly broken supersymmetry. The large hierarchy of energy scales in these geometries is stable. We establish this by showing that the dual gauge theories do not have any relevant operators which are singlets under the global symmetries. When the geometries are embedded in a compact internal space, a large enough discrete subgroup of the global symmetries can still survive to prevent any singlet relevant operators from arising. We illustrate this by embedding one case in a non-supersymmetric orbifold of a Calabi-Yau manifold. These examples can serve as a starting point for obtaining Randall-Sundrum models in string theory, and more generally for constructing composite Higgs or technicolor-like models where strongly coupled dynamics leads to the breaking of electro-weak symmetry. Towards the end of the paper, we briefly discuss how bulk gauge fields can be incorporated by introducing D7-branes in the bulk, and also show how the strongly coupled dynamics can lead to an emergent weakly coupled gauge theory in the IR with matter fields including scalars.
Date: June 28, 2011
Creator: Kachru, Shamit; Simic, Dusan; /Stanford U., ITP /SLAC /Santa Barbara, KITP; Trivedi, Sandip P. & /Tata Inst. /Stanford U., ITP /SLAC
Object Type: Article
System: The UNT Digital Library
Lifetime Measurement of the 2{sup +}{sub 1} state in {sup 20}C (open access)

Lifetime Measurement of the 2{sup +}{sub 1} state in {sup 20}C

Establishing how and when large N/Z values require modified or new theoretical tools is a major quest in nuclear physics. Here we report the first measurement of the lifetime of the 2{sup +}{sub 1} state in the near-dripline nucleus {sup 20}C. The deduced value of {tau}{sub #28;2{sup +}{sub 1}} = 9.8 ± 2.8(stat){sup +0.5}{sub −1.1}(syst) ps gives a reduced transition probability of B(E2;2{sup +}{sub 1}{yields}0{sup +}{sub g.s.}) = 7.5{sup +3.0}{sub −1.7}(stat){sup +1.0}{sub −0.4}(syst) e{sup 2}fm{sup 4} in good agreement with a shell model calculation using isospin-dependent effective charges.
Date: June 28, 2011
Creator: Petri, Marina-Kalliopi; Fallon, Paul; Macchiavelli, Augusto; Paschalis, Stephanos; Starosta, Krzysztof; Baugher, Travis et al.
Object Type: Article
System: The UNT Digital Library
Foreign Travel Trip Report for LLNL Travel with DOE FES Funding (open access)

Foreign Travel Trip Report for LLNL Travel with DOE FES Funding

None
Date: June 28, 2012
Creator: Meier, E T
Object Type: Report
System: The UNT Digital Library
INDEPENDENT CONFIRMATORY SURVEY OF THE NUCLEAR RESEARCH LABORATORY AT THE UNIVERSITY OF ILLINOIS URBANA-CHAMPAIGN, ILLINOIS (open access)

INDEPENDENT CONFIRMATORY SURVEY OF THE NUCLEAR RESEARCH LABORATORY AT THE UNIVERSITY OF ILLINOIS URBANA-CHAMPAIGN, ILLINOIS

ORAU conducted confirmatory survey activities within the NRL at the University during the week of May 7, 2012. The survey activities included visual inspections/ assessments, surface activity measurements, and volumetric concrete sampling activities. During the course of the confirmatory activities, ORAU noted several issues with the survey-for-release activities performed at the University. Issues included inconsistencies with: survey unit classifications were not designated according to Multi-Agency Radiation Survey and Site Investigation Manual guidance; survey instrument calibrations were not representative of the radionuclides of concern; calculations for instrumentation detection capabilities did not align with the release criteria discussed in the licensee’s survey guidance documents; total surface activity measurements were in excess of the release criteria; and Co-60 and Eu-152 concentrations in the confirmatory concrete samples were above their respective guidelines. Based on the significant programmatic issues identified, ORAU cannot independently conclude that the NRL satisfied the requirements and limits for release of materials without radiological restrictions.
Date: June 28, 2012
Creator: HARPENAU, EVAN M.
Object Type: Report
System: The UNT Digital Library
ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #050411 (open access)

ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #050411

Harrell Industries is under contract with Savannah River Remediation to provide Monosodium titanate (MST) for use in the Actinide Removal Process (ARP). A 500-mL qualification sample for Lot 050411 was sent to the Savannah River National Laboratory (SRNL) to confirm the material meets the requirements specified in the purchase specification. The vendor is also obligated to send verification samples from {approx}10% or more of the pails of MST product for each lot (distributed roughly evenly through the entire lot of pails). For the verification of this lot, Harrell Industries sent 12 samples, one each from pails No.1, 10, 20, 30, 40, 60, 70, 80, 90, 100, 110, and 120 of 120 total pails. MST for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot 050411 qualification and 12 verification samples met all the requirements in the specification indicating the material is acceptable for use in the process.
Date: June 28, 2011
Creator: Taylor-Pashow, K.
Object Type: Report
System: The UNT Digital Library
Irradiation Experiment Conceptual Design Parameters for MURR LEU U-Mo Fuel Conversion Revision (open access)

Irradiation Experiment Conceptual Design Parameters for MURR LEU U-Mo Fuel Conversion Revision

None
Date: June 28, 2013
Creator: Stillman, J.; Feldman, E.; Stevens, J.; Wilson, E.; Foyto, L.; Kutikkad, K. et al.
Object Type: Report
System: The UNT Digital Library
High Performance Computing Productivity Study - Evaluation of Parallel Tools Platform (PTP) Eclipse Plug-In (open access)

High Performance Computing Productivity Study - Evaluation of Parallel Tools Platform (PTP) Eclipse Plug-In

None
Date: June 28, 2012
Creator: Banks, Lawrence E. & Dube, Eveline I.
Object Type: Report
System: The UNT Digital Library
Productivity Techniques and Quality Aspects in the Criticality Safety Evaluation of Y-12 Type-B Fissile Material Packages (open access)

Productivity Techniques and Quality Aspects in the Criticality Safety Evaluation of Y-12 Type-B Fissile Material Packages

The inventory of certified Type-B fissile material packages consists of ten performance-based packages for offsite transportation purposes, serving transportation programs at the Y-12 National Security Complex. The containment vessels range from 5 to 19 in. in diameter and from 17 to 58 in. in height. The drum assembly external to the containment vessel ranges from 18 to 34 in. in diameter and from 26 to 71 in. in height. The weight of the packaging (drum assembly and containment vessel) ranges from 239 to 1550 lb. The older DT-nn series of Cellotex-based packages are being phased-out and replaced by a new generation of Kaolite-based ('Y-12 patented insulation') packages capable of withstanding the dynamic crush test 10 CFR 71.73(c)(2). Three replacement packages are in various stages of development; two are in use. The U.S. Department of Transportation (DOT) 6M specification package, which does not conform to the U.S. Nuclear Regulatory Commission requirements for Type-B packages, is no longer authorized for service on public roads. The ES-3100 shipping package is an example of a Kaolite-based Type-B fissile material package developed as a replacement package for the DOT 6M. With expanded utility, the ES-3100 is designed and licensed for transporting highly enriched uranium and …
Date: June 28, 2011
Creator: DeClue, J. F.
Object Type: Article
System: The UNT Digital Library
Baker-Barry Tunnel Lighting: Evaluation of a Potential GATEWAY Demonstrations Project (open access)

Baker-Barry Tunnel Lighting: Evaluation of a Potential GATEWAY Demonstrations Project

The U.S. Department of Energy is evaluating the Baker-Barry Tunnel as a potential GATEWAY Demonstrations project for deployment of solid-state lighting (SSL) technology. The National Park Service views this project as a possible proving ground and template for implementation of light-emitting diode (LED) luminaires in other tunnels, thereby expanding the estimated 40% energy savings from 132 MWh/yr to a much larger figure nationally. Most of the energy savings in this application is attributable to the instant-restrike capability of LED products and to their high tolerance for frequent on/off switching, used here to separately control either end of the tunnel during daytime hours. Some LED luminaires rival or outperform their high-intensity discharge (HID) counterparts in terms of efficacy, but options are limited, and smaller lumen packages preclude true one-for-one equivalence. However, LED products continue to improve in efficacy and affordability at a rate unmatched by other light source technologies; the estimated simple payback period of eight years (excluding installation costs and maintenance savings) can be expected to improve with time. The proposed revisions to the existing high-pressure sodium (HPS) lighting system would require slightly increased controls complexity and significantly increased luminaire types and quantities. In exchange, substantial annual savings (from reduced …
Date: June 28, 2011
Creator: Tuenge, Jason R.
Object Type: Report
System: The UNT Digital Library
Observation of Ultra-high-energy Cosmic Rays with the ANITA Balloon-borne Radio Interferometer (open access)

Observation of Ultra-high-energy Cosmic Rays with the ANITA Balloon-borne Radio Interferometer

None
Date: June 28, 2013
Creator: Hoover, S.; Nam, J.; Gorham, P. W.; Grashorn, E.; Allison, P.; Barwick, S. W. et al.
Object Type: Article
System: The UNT Digital Library
Power Supply Changes for NSTX Resistive Wall Mode Coils (open access)

Power Supply Changes for NSTX Resistive Wall Mode Coils

The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physics Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. Prior to 2004, the NSTX power system was feeding twelve (12) circuits in the machine. In 2004 the Resistive Wall Mode (RWM) Coils were installed on the machine to correct error fields. There are six of these coils installed around the machine in the mid-plane. Since these coils need fast and accurate controls, a Switching Power Amplifier (SPA) with three sub-units was procured, installed and commissioned along with other power loop components. Two RWM Coils were connected in series and fed from one SPA sub-unit. After the initial RWM campaign, operational requirements evolved such that each of the RWM coils now requires separate power and control. Hence a second SPA with three sub-units has been procured and installed. The second unit is of improved design and has the controls and power components completely isolated. The existing thyristor rectifier is used as DC Link to both of the Switching Power …
Date: June 28, 2013
Creator: Ramakrishnan, S S.
Object Type: Article
System: The UNT Digital Library
ARM User Survey Report: Data Access, Quality, and Delivery (open access)

ARM User Survey Report: Data Access, Quality, and Delivery

The objective of this survey was to obtain user feedback to determine how users of the Atmospheric Radiation Measurement (ARM) Climate Research Facility Data Archive interact with the more than 2000 available types of datastreams. The survey also gathered information about data discovery and data quality. The Market and Competitive Analysis group at Pacific Northwest National Laboratory worked with web administrators to develop a landing page from which users could access the survey. A survey invitation was sent by ARM via email to about 6100 users on February 22, 2012. The invitation was also posted on the ARM website and Facebook page. Reminders were sent via e-mail and posted on Facebook while the survey was open, February 22-March 23, 2012.
Date: June 28, 2012
Creator: Mather, JH; Roeder, LR & Sivaraman, C
Object Type: Text
System: The UNT Digital Library
New Physics at the LHC. a Les Houches Report: Physics at TeV Colliders 2009 - New Physics Working Group (open access)

New Physics at the LHC. a Les Houches Report: Physics at TeV Colliders 2009 - New Physics Working Group

None
Date: June 28, 2013
Creator: Brooijmans, G.; Grojean, C.; Kribs, G. D.; Shepherd-Themistocleous, C.; Agashe, K.; Basso, L. et al.
Object Type: Article
System: The UNT Digital Library
The History of X-ray Free-Electron Lasers (open access)

The History of X-ray Free-Electron Lasers

The successful lasing at the SLAC National Accelerator Laboratory of the Linear Coherent Light Source (LCLS), the first X-ray free-electron laser (X-ray FEL), in the wavelength range 1.5 to 15 {angstrom}, pulse duration of 60 to few femtoseconds, number of coherent photons per pulse from 10{sup 13} to 10{sup 11}, is a landmark event in the development of coherent electromagnetic radiation sources. Until now electrons traversing an undulator magnet in a synchrotron radiation storage ring provided the best X-ray sources. The LCLS has set a new standard, with a peak X-ray brightness higher by ten orders of magnitudes and pulse duration shorter by three orders of magnitudes. LCLS opens a new window in the exploration of matter at the atomic and molecular scales of length and time. Taking a motion picture of chemical processes in a few femtoseconds or less, unraveling the structure and dynamics of complex molecular systems, like proteins, are some of the exciting experiments made possible by LCLS and the other X-ray FELs now being built in Europe and Asia. In this paper, we describe the history of the many theoretical, experimental and technological discoveries and innovations, starting from the 1960s and 1970s, leading to the development …
Date: June 28, 2012
Creator: Pellegrini, C. & /SLAC, /UCLA
Object Type: Article
System: The UNT Digital Library
Adaptive Wavenumber Estimation for Mode Tracking in a Shallow Ocean Environment (open access)

Adaptive Wavenumber Estimation for Mode Tracking in a Shallow Ocean Environment

None
Date: June 28, 2012
Creator: Candy, J V
Object Type: Article
System: The UNT Digital Library
Evaluation of Thermodynamic Data (open access)

Evaluation of Thermodynamic Data

None
Date: June 28, 2013
Creator: Wolery, T J & Sutton, M
Object Type: Report
System: The UNT Digital Library
Collaborative Research: The Influence of Cloud Microphysics and Radiation on the Response of Water Vapor and Clouds to Climate Change (open access)

Collaborative Research: The Influence of Cloud Microphysics and Radiation on the Response of Water Vapor and Clouds to Climate Change

Uncertainties in representing the atmospheric water cycle are major obstacles to an accurate prediction of future climate. This project focused on addressing some of these uncertainties by implementing new physics for convection and radiation into the NCAR climate model. To better understand and eventually better represent these processes, we modified CAM3.5 to use the convection and cloud schemes developed by the Massachusetts Institute of Technology (MIT) and the RRTMG rapid radiation code for global models developed by Atmospheric and Environmental Research, Inc. (AER). The impact of the new physics on the CAM3.5 simulation of convection on diurnal and intra-seasonal scales, intra-seasonal oscillations and the distribution of water vapor has been investigated. The effect of the MIT and AER physics also has been tested in the Weather Research and Forecasting (WRF) regional forecast model. It has been found that the application of the AER radiation and MIT convection produces significant improvements in the modeled diurnal cycle of convection, especially over land, in the NCAR climate model. However, both the standard CAM3.5 (hereinafter STD) and the modified CAM3.5 with the new physics (hereinafter MOD) are still unable to capture the proper spectrum and propagating characteristics of the intra-seasonal oscillations (ISOs). The new …
Date: June 28, 2011
Creator: Emanuel, Dr. Kerry & Iacono, Michael J.
Object Type: Report
System: The UNT Digital Library
Test of Lepton Universality and Searches for Lepton Flavor Violation at BaBar (open access)

Test of Lepton Universality and Searches for Lepton Flavor Violation at BaBar

None
Date: June 28, 2013
Creator: Guido, Elisa & /Genoa U. /INFN, Genoa
Object Type: Article
System: The UNT Digital Library
Fermi Large Area Telescope Operations: Progress Over 4 Years (open access)

Fermi Large Area Telescope Operations: Progress Over 4 Years

The Fermi Gamma-ray Space Telescope was launched into orbit in June 2008, and is conducting a multi-year gamma-ray all-sky survey, using the main instrument on Fermi, the Large Area Telescope (LAT). Fermi began its science mission in August 2008, and has now been operating for almost 4 years. The SLAC National Accelerator Laboratory hosts the LAT Instrument Science Operations Center (ISOC), which supports the operation of the LAT in conjunction with the Mission Operations Center (MOC) and the Fermi Science Support Center (FSSC), both at NASA's Goddard Space Flight Center. The LAT has a continuous output data rate of about 1.5 Mbits per second, and data from the LAT are stored on Fermi and transmitted to the ground through TDRS and the MOC to the ISOC about 10 times per day. Several hundred computers at SLAC are used to process LAT data to perform event reconstruction, and gamma-ray photon data are subsequently delivered to the FSSC for public release with a few hours of being detected by the LAT. We summarize the current status of the LAT, and the evolution of the data processing and monitoring performed by the ISOC during the first 4 years of the Fermi mission, together …
Date: June 28, 2012
Creator: Cameron, Robert A.
Object Type: Article
System: The UNT Digital Library
The Discovery of gamma-Ray Emission From The Blazar RGB J0710+591 (open access)

The Discovery of gamma-Ray Emission From The Blazar RGB J0710+591

None
Date: June 28, 2013
Creator: Acciari, V. A.; Aliu, E.; Arlen, T.; Aune, T.; Bautista, M.; Beilicke, M. et al.
Object Type: Article
System: The UNT Digital Library
Hardwired Control Changes For NSTX DC Power Feeds (open access)

Hardwired Control Changes For NSTX DC Power Feeds

The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physics Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. The original TFTR Hardwired Control System (HCS) with electromechanical relays was used for NSTX DC Power loop control and protection during NSTX operations. As part of the NSTX Upgrade, the HCS is being changed to a PLC-based system with the same control logic. This paper gives a description of the changeover to the new PLC-based system __________________________________________________
Date: June 28, 2013
Creator: Ramakrishnan, S.
Object Type: Article
System: The UNT Digital Library
Molecular Design Basis for Hydrogen Storage in Clathrate Hydrates (open access)

Molecular Design Basis for Hydrogen Storage in Clathrate Hydrates

We attach a final technical report for the project. The report contains the list of all peer reviewed publications that have resulted from the contract. I will be happy to send the pdf files of the papers.
Date: June 28, 2013
Creator: John, Vijay T; McPherson, Gary L; Ashbaugh, Hank & Johnes, Camille Y
Object Type: Report
System: The UNT Digital Library
DEVELOPMENT OF IMPROVED TECHNIQUES FOR SATELLITE REMOTE SENSING OF CLOUDS AND RADIATION USING ARM DATA, FINAL REPORT (open access)

DEVELOPMENT OF IMPROVED TECHNIQUES FOR SATELLITE REMOTE SENSING OF CLOUDS AND RADIATION USING ARM DATA, FINAL REPORT

During the period, March 1997 – February 2006, the Principal Investigator and his research team co-authored 47 peer-reviewed papers and presented, at least, 138 papers at conferences, meetings, and workshops that were supported either in whole or in part by this agreement. We developed a state-of-the-art satellite cloud processing system that generates cloud properties over the Atmospheric Radiation (ARM) surface sites and surrounding domains in near-real time and outputs the results on the world wide web in image and digital formats. When the products are quality controlled, they are sent to the ARM archive for further dissemination. These products and raw satellite images can be accessed at http://cloudsgate2.larc.nasa.gov/cgi-bin/site/showdoc?docid=4&cmd=field-experiment-homepage&exp=ARM and are used by many in the ARM science community. The algorithms used in this system to generate cloud properties were validated and improved by the research conducted under this agreement. The team supported, at least, 11 ARM-related or supported field experiments by providing near-real time satellite imagery, cloud products, model results, and interactive analyses for mission planning, execution, and post-experiment scientific analyses. Comparisons of cloud properties derived from satellite, aircraft, and surface measurements were used to evaluate uncertainties in the cloud properties. Multiple-angle satellite retrievals were used to determine the influence …
Date: June 28, 2013
Creator: Minnis, Patrick
Object Type: Report
System: The UNT Digital Library