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Discovery of Very High Energy Gamma Rays from PKS 1424+240 and Multiwavelength Constraints on its Redshift (open access)

Discovery of Very High Energy Gamma Rays from PKS 1424+240 and Multiwavelength Constraints on its Redshift

We report the first detection of very-high-energy (VHE) gamma-ray emission above 140GeV from PKS 1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140GeV measured by VERITAS is well described by a power law with a photon index of 3.8 {+-}0.5{sub stat} {+-} 0.3{sub syst} and a flux normalization at 200 GeV of (5.1 {+-} 0.9{sub stat} {+-} 0.5{sub syst}) x 10{sup -11} TeV{sup -1} cm{sup -2} s{sup -1}, where stat and syst denote the statistical and systematical uncertainty, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high energy observations with the Fermi Large Area Telescope (LAT). Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution (SED) is well described by a one-zone synchrotron self-Compton (SSC) model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light (EBL) absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66.
Date: April 5, 2012
Creator: Acciari, V. A.; Aliu, E.; Arlen, T.; Aune, T.; Bautista, M.; Beilicke, M. et al.
System: The UNT Digital Library
The European Union: Questions and Answers (open access)

The European Union: Questions and Answers

This report provides a brief overview of the European Union (EU), an economic and political partnership between 27 sovereign member states. The report describes the formation of the EU, the three main institutions of the EU, and the EU's relationship with the United States.
Date: April 5, 2012
Creator: Archick, Kristin
System: The UNT Digital Library
Western Sahara (open access)

Western Sahara

This report discusses how Morocco and the independence-seeking Popular Front for the Liberation of Saqiat al Hamra and Rio de Oro (Polisario) have been vying for control of the Western Sahara, a former Spanish territory, since the 1970s. The report discusses recent settlement attempts, as well as how the Western Sahara issue has affected Algerian-Moroccan bilaterial relations, Moroccan relations with the African Union, and regional cooperation on economic and security issues. The report also discusses the United States' involvement in and stance on the issue.
Date: April 5, 2012
Creator: Arieff, Alexis
System: The UNT Digital Library
Pacific Northwest National Laboratory Potential Impact Categories for Radiological Air Emission Monitoring (open access)

Pacific Northwest National Laboratory Potential Impact Categories for Radiological Air Emission Monitoring

In 2002, the EPA amended 40 CFR 61 Subpart H and 40 CFR 61 Appendix B Method 114 to include requirements from ANSI/HPS N13.1-1999 Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities for major emission points. Additionally, the WDOH amended the Washington Administrative Code (WAC) 246-247 Radiation protection-air emissions to include ANSI/HPS N13.1-1999 requirements for major and minor emission points when new permitting actions are approved. A result of the amended regulations is the requirement to prepare a written technical basis for the radiological air emission sampling and monitoring program. A key component of the technical basis is the Potential Impact Category (PIC) assigned to an emission point. This paper discusses the PIC assignments for the Pacific Northwest National Laboratory (PNNL) Integrated Laboratory emission units; this revision includes five PIC categories.
Date: June 5, 2012
Creator: Ballinger, Marcel Y.; Gervais, Todd L. & Barnett, J. M.
System: The UNT Digital Library
High Cost/High Risk Components to Chalcogenide Molded Lens Model: Molding Preforms and Mold Technology (open access)

High Cost/High Risk Components to Chalcogenide Molded Lens Model: Molding Preforms and Mold Technology

This brief report contains a critique of two key components of FiveFocal's cost model for glass compression molding of chalcogenide lenses for infrared applications. Molding preforms and mold technology have the greatest influence on the ultimate cost of the product and help determine the volumes needed to select glass molding over conventional single-point diamond turning or grinding and polishing. This brief report highlights key areas of both technologies with recommendations for further study.
Date: October 5, 2012
Creator: Bernacki, Bruce E.
System: The UNT Digital Library
U.S. Foreign-Trade Zones: Background and Issues for Congress (open access)

U.S. Foreign-Trade Zones: Background and Issues for Congress

Report that provides a general perspective on the U.S. Foreign-Trade Zone (FTZ) system. The first section discusses free trade zones worldwide. The second section focuses on the U.S. FTZ program --its history, administrative mechanism, structure, growth and industry concentration, and benefits and costs. The third section focuses on current issues for Congress relating to the U.S. FTZ program.
Date: September 5, 2012
Creator: Bolle, Mary Jane & Williams, Brock R.
System: The UNT Digital Library
Wildfires: CRS Experts (open access)

Wildfires: CRS Experts

The following table provides access to names and contact information for CRS experts on policy concerns relating to wildfires. Policy areas identified include federal wildfire policy; long-term land use management; federal firefighting assistance; federal emergency management policy; federal preparedness system and response plan; hazard mitigation; armed forces and national guard assistance; supplemental disaster funding; and disaster insurance.
Date: July 5, 2012
Creator: Bracmort, Kelsi
System: The UNT Digital Library
Radar-cross-section reduction of wind turbines. part 1. (open access)

Radar-cross-section reduction of wind turbines. part 1.

In recent years, increasing deployment of large wind-turbine farms has become an issue of growing concern for the radar community. The large radar cross section (RCS) presented by wind turbines interferes with radar operation, and the Doppler shift caused by blade rotation causes problems identifying and tracking moving targets. Each new wind-turbine farm installation must be carefully evaluated for potential disruption of radar operation for air defense, air traffic control, weather sensing, and other applications. Several approaches currently exist to minimize conflict between wind-turbine farms and radar installations, including procedural adjustments, radar upgrades, and proper choice of low-impact wind-farm sites, but each has problems with limited effectiveness or prohibitive cost. An alternative approach, heretofore not technically feasible, is to reduce the RCS of wind turbines to the extent that they can be installed near existing radar installations. This report summarizes efforts to reduce wind-turbine RCS, with a particular emphasis on the blades. The report begins with a survey of the wind-turbine RCS-reduction literature to establish a baseline for comparison. The following topics are then addressed: electromagnetic model development and validation, novel material development, integration into wind-turbine fabrication processes, integrated-absorber design, and wind-turbine RCS modeling. Related topics of interest, including alternative …
Date: March 5, 2012
Creator: Brock, Billy C.; Loui, Hung; McDonald, Jacob J.; Paquette, Joshua A.; Calkins, David A.; Miller, William K. et al.
System: The UNT Digital Library
Legal Analysis of Religious Exemptions for Photo Identification Requirements (open access)

Legal Analysis of Religious Exemptions for Photo Identification Requirements

Report that analyzes the legal issues associated with religious exemptions to photo identification laws, lawsuits that have challenged state photo requirements, and factors that may be relevant in future decisions that may arise related to federal photo identification requirements and state voter identification requirements.
Date: September 5, 2012
Creator: Brougher, Cynthia
System: The UNT Digital Library
The Endangered Species Act (ESA) in the 112th Congress: Conflicting Values and Difficult Choices (open access)

The Endangered Species Act (ESA) in the 112th Congress: Conflicting Values and Difficult Choices

The Endangered Species Act has been one of the more contentious environmental laws. This may stem from its strict substantive provisions, which can affect the use of both federal and nonfederal lands and resources. This report discusses oversight issues and legislation introduced in the 112th Congress to address Endangered Species Act implementation and management of endangered and threatened species.
Date: November 5, 2012
Creator: Buck, Eugene H.; Corn, M. Lynne; Alexander, Kristina; Sheikh, Pervaze A. & Meltz, Robert
System: The UNT Digital Library
Characterization of fundamental catalytic properties of MoS2/WS2 nanotubes and nanoclusters for desulfurization catalysis - a surface temperature study (open access)

Characterization of fundamental catalytic properties of MoS2/WS2 nanotubes and nanoclusters for desulfurization catalysis - a surface temperature study

The prior project consisted of two main project lines. First, characterization of novel nanomaterials for hydrodesulfurization (HDS) applications. Second, studying more traditional model systems for HDS such as vapor-deposited silica-supported Mo and MoSx clusters. In the first subproject, we studied WS2 and MoS2 fullerene-like nanoparticles as well as WS2 nanotubes. Thiophene (C4H4S) was used as the probe molecule. Interestingly, metallic and sulfur-like adsorption sites could be identified on the silica-supported fullerene-particles system. Similar structures are seen for the traditional system (vapor-deposited clusters). Thus, this may be a kinetics fingerprint feature of modern HDS model systems. In addition, kinetics data allowed characterization of the different adsorption sites for thiophene on and inside WS2 nanotube bundles. The latter is a unique feature of nanotubes that has not been reported before for any inorganic nanotube system; however, examples are known for carbon nanotubes, including prior work of the PI. Although HDS has been studied for decades, utilizing nanotubes as nanosized HDS reactors has never been tried before, as far as we know. This is of interest from a fundamental perspective. Unfortunately, the HDS activity of the nanocatalysts at ultra-high vacuum (UHV) conditions was close to the detection limit of our techniques. Therefore, we …
Date: July 5, 2012
Creator: Burghaus, U.
System: The UNT Digital Library
The Repeal of "Don't Ask, Don't Tell": Issues for Congress (open access)

The Repeal of "Don't Ask, Don't Tell": Issues for Congress

On December 22, 2010, President Obama signed into law legislation calling for the repeal of the existing law barring open homosexuality in the military by prescribing a series of steps that must take place before repeal occurs. One step was fulfilled on July 22, 2011, when the President signed the certification of the process ending the Don't Ask, Don't Tell policy, which was repealed on September 20, 2011. This report considers issues that Congress may wish to consider as the repeal process proceeds.
Date: April 5, 2012
Creator: Burrelli, David F.
System: The UNT Digital Library
Women in Combat: Issues for Congress (open access)

Women in Combat: Issues for Congress

This report looks at the history of women in US military roles and combat since the 1990's. It also discusses critic's views of exclusionary policy as a civil rights issue.
Date: April 5, 2012
Creator: Burrelli, David F.
System: The UNT Digital Library
FY2012 National Defense Authorization Act: Selected Military Personnel Policy Issues (open access)

FY2012 National Defense Authorization Act: Selected Military Personnel Policy Issues

This report focuses exclusively on the annual defense authorization process. It does not include language concerning appropriations, veterans' affairs, tax implications of policy choices, or any discussion of separately introduced legislation.
Date: January 5, 2012
Creator: Burrelli, David F.; Henning, Charles A.; Jansen, Don J. & Kapp, Lawrence
System: The UNT Digital Library
Fusion Simulation Program Definition. Final report (open access)

Fusion Simulation Program Definition. Final report

We have completed our contributions to the Fusion Simulation Program Definition Project. Our contributions were in the overall planning with concentration in the definition of the area of Software Integration and Support. We contributed to the planning of multiple meetings, and we contributed to multiple planning documents.
Date: September 5, 2012
Creator: Cary, John R.
System: The UNT Digital Library
COLLABORATIVE: FUSION SIMULATION PROGRAM (open access)

COLLABORATIVE: FUSION SIMULATION PROGRAM

New York University, Courant Institute of Mathematical Sciences, participated in the “Fusion Simulation Program (FSP) Planning Activities” [http://www.pppl.gov/fsp], with C.S. Chang as the institutional PI. FSP’s mission was to enable scientific discovery of important new plasma phenomena with associated understanding that emerges only upon integration. This requires developing a predictive integrated simulation capability for magnetically-confined fusion plasmas that are properly validated against experiments in regimes relevant for producing practical fusion energy. Specific institutional goal of the New York University was to participate in the planning of the edge integrated simulation, with emphasis on the usage of large scale HPCs, in connection with the SciDAC CPES project which the PI was leading. New York University successfully completed its mission by participating in the various planning activities, including the edge physics integration, the edge science drivers, and the mathematical verification. The activity resulted in the combined report that can be found in http://www.pppl.gov/fsp/Overview.html. Participation and presentations as part of this project are listed in a separation file.
Date: June 5, 2012
Creator: Chang, Choong Seock
System: The UNT Digital Library
Thailand: Background and U.S. Relations (open access)

Thailand: Background and U.S. Relations

This report looks at the relationship between the U.S. and Thailand, in particular, recent rivalries between populist political forces, neopotism in government, and Thai relationships with neighboring countries.
Date: June 5, 2012
Creator: Chanlett-Avery, Emma & Dolven, Ben
System: The UNT Digital Library
Release of aged contaminants from weathered sediments: Effects of sorbate speciation on scaling of reactive transport (open access)

Release of aged contaminants from weathered sediments: Effects of sorbate speciation on scaling of reactive transport

Hanford sediments impacted by hyperalkaline high level radioactive waste have undergone incongruent silicate mineral weathering concurrent with contaminant uptake. In this project, we studied the impact of background pore water (BPW) on strontium, cesium and iodine desorption and transport in Hanford sediments that were experimentally weathered by contact with simulated hyperalkaline tank waste leachate (STWL) solutions. Using those lab-weathered Hanford sediments (HS) and model precipitates formed during nucleation from homogeneous STWL solutions (HN), we (i) provided thorough characterization of reaction products over a matrix of field-relevant gradients in contaminant concentration, partial pressure of carbon dioxide, and reaction time; (ii) improved molecular-scale understanding of how sorbate speciation controls contaminant desorption from weathered sediments upon removal of caustic sources; and (iii) developed a mechanistic, predictive model of meso- to field-scale contaminant reactive transport under these conditions. In this final report, we provide detailed descriptions of our results from this three-year study, completed in 2012 following a one-year no cost extension.
Date: November 5, 2012
Creator: Chorover, Jon; Perdrial, Nico; Mueller, Karl; Strepka, Caleb; O’Day, Peggy; Rivera, Nelson et al.
System: The UNT Digital Library
The Army Corps of Engineers’ Nationwide Permits Program: Issues and Regulatory Developments (open access)

The Army Corps of Engineers’ Nationwide Permits Program: Issues and Regulatory Developments

This report contains the issues and regulatory developments in the army corps engineers' nationwide permits program.
Date: April 5, 2012
Creator: Copeland, Claudia
System: The UNT Digital Library
Water Infrastructure Financing: History of EPA Appropriations (open access)

Water Infrastructure Financing: History of EPA Appropriations

None
Date: April 5, 2012
Creator: Copeland, Claudia
System: The UNT Digital Library
Water Quality Issues in the 112th Congress: Oversight and Implementation (open access)

Water Quality Issues in the 112th Congress: Oversight and Implementation

None
Date: October 5, 2012
Creator: Copeland, Claudia
System: The UNT Digital Library
Congressional Investigations of the Department of Justice, 1920-2012: History, Law, and Practice (open access)

Congressional Investigations of the Department of Justice, 1920-2012: History, Law, and Practice

This report briefly reviews the legal basis for investigative oversight, followed by several prominent examples of congressional oversight that reflect the significant breadth and reach of the legislative investigative prerogative vis-à-vis the Department. The report alos reviews and assess the Department’s contentions, based on policy, common law, and constitutional privilege, that it has asserted to attempt to limit congressional access to agency information.
Date: November 5, 2012
Creator: Dolan, Alissa M. & Garvey, Todd
System: The UNT Digital Library
Infrared Spectroscope for Electron Bunch-length Measurement: Heat Sensor Parameters Analysis (open access)

Infrared Spectroscope for Electron Bunch-length Measurement: Heat Sensor Parameters Analysis

The Linac Coherent Light Source (LCLS) is used for many experiments. Taking advantage of the free electron laser (FEL) process, scientists of various fields perform experiments of all kind. Some for example study protein folding; other experiments are more interested in the way electrons interact with the molecules before they are destroyed. These experiments among many others have very little information about the electrons x-ray produced by the FEL, except that the FEL is using bunches less than 10 femtoseconds long. To be able to interpret the data collected from those experiments, more accurate information is needed about the electron's bunch-length. Existing bunch length measurement techniques are not suitable for the measurement of such small time scales. Hence the need to design a device that will provide more precise information about the electron bunch length. This paper investigates the use of a pyreoelectric heat sensor that has a sensitivity of about 1.34 micro amps per watt for the single cell detector. Such sensitivity, added to the fact that the detector is an array sensor, makes the detector studied the primary candidate to be integrated to an infrared spectrometer designed to better measure the LCLS electron bunch length.
Date: September 5, 2012
Creator: Domgmo-Momo, Gilles & /SLAC, /Towson U.
System: The UNT Digital Library
Unitarity Bounds and RG Flows in Time Dependent Quantum Field Theory (open access)

Unitarity Bounds and RG Flows in Time Dependent Quantum Field Theory

We generalize unitarity bounds on operator dimensions in conformal field theory to field theories with spacetime dependent couplings. Below the energy scale of spacetime variation of the couplings, their evolution can strongly affect the physics, effectively shifting the infrared operator scaling and unitarity bounds determined from correlation functions in the theory. We analyze this explicitly for large-N double-trace flows, and connect these to UV complete field theories. One motivating class of examples comes from our previous work on FRW holography, where this effect explains the range of flavors allowed in the dual, time dependent, field theory.
Date: April 5, 2012
Creator: Dong, Xi; Horn, Bart; Silverstein, Eva; Torroba, Gonzalo & /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC
System: The UNT Digital Library