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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
Attrition Resistant Fischer-Tropsch Catalysts Based on FCC Supports
Commercial spent fluid catalytic cracking (FCC) catalysts provided by Engelhard and Albemarle were used as supports for Fe-based catalysts with the goal of improving the attrition resistance of typical F-T catalysts. Catalysts with the Ruhrchemie composition (100 Fe/5 Cu/4.2 K/25 spent FCC on mass basis) were prepared by wet impregnation. XRD and XANES analysis showed the presence of Fe{sub 2}O{sub 3} in calcined catalysts. FeC{sub x} and Fe{sub 3}O{sub 4} were present in the activated catalysts. The metal composition of the catalysts was analyzed by ICP-MS. F-T activity of the catalysts activated in situ in CO at the same conditions as used prior to the attrition tests was measured using a fixed bed reactor at T = 573 K, P = 1.38 MPa and H{sub 2}:CO ratio of 0.67. Cu and K promoted Fe supported over Engelhard provided spent FCC catalyst shows relatively good attrition resistance (8.2 wt% fines lost), high CO conversion (81%) and C{sub 5}+ hydrocarbons selectivity (18.3%).
Date:
February 5, 2010
Creator:
Adeyiga, Adeyinka
System:
The UNT Digital Library
Trade Primer: Qs and As on Trade Concepts, Performance, and Policy
The 112th Congress has a full legislative and oversight agenda on international trade. The agenda may include considering legislation to implement pending free trade agreements with Panama, South Korea, and Colombia, enhanced enforcement of U.S. trade agreements, as well as oversight of the World Trade Organization's Doha Round and trade relations with China. This report provides information and context for many of these topics. The report is divided into four sections in a question-and-answer format: trade concepts, U.S. trade performance, formulation of U.S. trade policy, and trade and investment issues.
Date:
January 5, 2011
Creator:
Ahearn, Raymond J.
System:
The UNT Digital Library
Erosion-Resistant Nanocoatings for Improved Energy Efficiency in Gas Turbines
The objective of this Stage Gate IV project was to test and substantiate the viability of an erosion‐resistant nanocoating for application on compressor airfoils for gas turbines in both industrial power generation and commercial aviation applications. To effectively complete this project, the National Energy Technology Laboratory’s Office of Research & Development teamed with MDS Coating Technologies Inc. (MCT), Delta Air Lines ‐ Technical Operations Division (Delta Tech Ops), and Calpine Corporation. The coating targeted for this application was MCT’s Next Generation Coating, version 4 (NGC‐v4 ‐ with the new registered trademark name of BlackGold®). The coating is an erosion and corrosion resistant composite nanostructured coating. This coating is comprised of a proprietary ceramic‐metallic nano‐composite construction which provides enhanced erosion resistance and also retains the aerodynamic geometry of the airfoils. The objective of the commercial aviation portion of the project was to substantiate the coating properties to allow certification from the FAA to apply an erosion‐resistant coating in a commercial aviation engine. The goal of the series of tests was to demonstrate that the durability of the airfoils is not affected negatively with the application of the NGC v4 coating. Tests included erosion, corrosion, vibration and fatigue. The results of the …
Date:
February 5, 2014
Creator:
Alman, David & Marcio, Duffles
System:
The UNT Digital Library
The First Day of a New Congress: A Guide to Proceedings on the Senate Floor
The Senate follows a well-established routine on the opening day of a new Congress. The proceedings include swearing in new members, administrative business, and the election of the president pro tempore, the constitutionally mandated officer elected to preside over the chamber in the absence of the Vice President. This report contains information on what is contained in the well-established routine.
Date:
December 5, 2014
Creator:
Amer, Mildred L.
System:
The UNT Digital Library
Final Report: Imaging of Buried Nanoscale Optically Active Materials
This is a final report covering work done at University of Maryland to develop a Ballistic Electron Emission Luminescence (BEEL) microscope. This technique was intended to examine the carrier transport and photon emission in deeply buried optically-active layers and thereby provide a means for materials science to unmask the detailed consequences of experimentally controllable growth parameters, such as quantum dot size, statistics and orientation, and defect density and charge recombination pathways.
Date:
July 5, 2011
Creator:
Appelbaum, Ian
System:
The UNT Digital Library
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
The European Parliament
The European Parliament (EP) is one of the three key institutions of the European Union (EU), and the only EU institution whose members are directly elected. This report discusses the construction and history of the EP, its role in functions of the EU as well as internationally, various international supports and criticisms of the EP, and the EP's ties with the U.S. Congress.
Date:
November 5, 2010
Creator:
Archick, Kristin & Mix, Derek E.
System:
The UNT Digital Library
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:
November 5, 2010
Creator:
Archick, Kristin & Mix, Derek E.
System:
The UNT Digital Library
A Harmonic Approach for Calculating Daily Temperature Normals Constrained by Homogenized Monthly Temperature Normals
A report offering a constrained harmonic technique that forces the daily temperature normals to be consistent with the monthly temperature normals that NOAA archived between 1981 and 2010.
Date:
February 5, 2013
Creator:
Arguez, Anthony & Applequist, Scott
System:
The UNT Digital Library
Attack on U.S. Soldiers in Niger: Context and Issues for Congress
This report discusses an attack on U.S. Special Operation Forces assisting local military forces in Niger in counterterrorism efforts which killed four U.S. military personnel and wounded two as well as killing several Niger military personnel. The U.S. response to the attack, the growing threat of Islamic extremism and terrorism in the Sahel of Africa, and terrorism and political and social instability in Niger are also discussed.
Date:
October 5, 2017
Creator:
Arieff, Alexis
System:
The UNT Digital Library
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
Discretionary Budget Authority by Subfunction: An Overview
This report presents figures showing trends in discretionary budget authority as a percentage of gross domestic product (GDP) by subfunction within each of 17 budget function categories, using data from President Obama's FY2016 budget submission. This report provides a graphical overview of historical trends in discretionary budget authority from FY1977 through FY2014, estimates for FY2015 spending, and the levels consistent with the President's proposals for FY2016 through FY2020.
Date:
February 5, 2015
Creator:
Austin, D. Andrew
System:
The UNT Digital Library
The Debt Limit: History and Recent Increases
This report discusses how the total debt of the federal government can increase, including an historical overview of debt limits, and how the current economic slowdown has led to higher deficits and thereby a series of debt limit increases, as well as legislation related to these increases.
Date:
April 5, 2011
Creator:
Austin, D. Andrew & Levit, Mindy R.
System:
The UNT Digital Library
Questions Remain, Litigation Continues, over Military Service by Transgender Individuals
This report discusses the controversy regarding transgender individuals serving in the military, President Trump's memorandums on the subject, and the four lawsuits challenging the President's memorandums.
Date:
July 5, 2018
Creator:
Back, Christine J.
System:
The UNT Digital Library
Traumatic Brain Injury Among Veterans
Traumatic Brain Injury (TBI) has been defined as "an alteration in brain function, or other evidence of brain pathology, caused by an external force." In the general population, TBI results mainly from falls, motor vehicle/traffic accidents, assaults, and other instances in which the head is struck by or strikes against an object. In military service members, TBI may also result from improvised explosive devices, mortars, grenades, bullets, or mines.
Date:
May 5, 2011
Creator:
Bagalman, Erin
System:
The UNT Digital Library
Defense Surplus Equipment Disposal, Including the Law Enforcement 1033 Program
This report focuses on the disposal of defense surplus property that is delegated to Department of Defense (DOD) from the General Services Administration. Law enforcement agencies are a recipient of defense surplus property, along with many other recipients.
Date:
September 5, 2014
Creator:
Bailey Grasso, Valerie
System:
The UNT Digital Library
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
Results For The Fourth Quarter 2012 Tank 50 WAC Slurry Sample: Chemical And Radionuclide Contaminants
This report details the chemical and radionuclide contaminant results for the characterization of the 2012 Fourth Quarter sampling of Tank 50 for the Saltstone Waste Acceptance Criteria (WAC).Information from this characterization will be used by Waste Solidification Engineering (WSE) to support the transfer of low-level aqueous waste from Tank 50 to the Salt Feed Tank in the Saltstone Facility in Z-Area, where the waste will be immobilized. This information is also used to update the Tank 50 Waste Characterization System. The following conclusions are drawn from the analytical results provided in this report: The concentration of the reported chemical and radioactive contaminants were less than their respective WAC Limits and Targets, unless noted in this section; Norpar 13 and Isopar L have higher detection limits compared with the Saltstone WAC. The data provided in this report is based upon the concentrations in the sub-sample, and due to the limited solubility in aqueous solution, may not represent the concentrations of the analytes in Tank 50; Diisooctyl adipate (or diisooctyl hexanedioate) and 5-methyl-3-hexanol, plasticizers, were measured at 1.30E+00 mg/L and 3.00E+00 mg/L, respectively, in one of two replicate measurements conducted on an at-depth sample. The organic analysis of the at-depth sample was …
Date:
February 5, 2013
Creator:
Bannochie, C. J.
System:
The UNT Digital Library
NANOSTRUCTURED METAL OXIDE CATALYSTS VIA BUILDING BLOCK SYNTHESES
A broadly applicable methodology has been developed to prepare new single site catalysts on silica supports. This methodology requires of three critical components: a rigid building block that will be the main structural and compositional component of the support matrix; a family of linking reagents that will be used to insert active metals into the matrix as well as cross link building blocks into a three dimensional matrix; and a clean coupling reaction that will connect building blocks and linking agents together in a controlled fashion. The final piece of conceptual strategy at the center of this methodology involves dosing the building block with known amounts of linking agents so that the targeted connectivity of a linking center to surrounding building blocks is obtained. Achieving targeted connectivities around catalytically active metals in these building block matrices is a critical element of the strategy by which single site catalysts are obtained. This methodology has been demonstrated with a model system involving only silicon and then with two metal-containing systems (titanium and vanadium). The effect that connectivity has on the reactivity of atomically dispersed titanium sites in silica building block matrices has been investigated in the selective oxidation of phenols to benezoquinones. …
Date:
March 5, 2013
Creator:
Barnes, Craig E.
System:
The UNT Digital Library
Energy and Water Development: FY2010 Appropriations
This report discusses the Energy and Water Development appropriations bill that provides funding for civil works projects of the Army Corps of Engineers (Corps), for the Department of the Interior's Bureau of Reclamation (Reclamation), the Department of Energy (DOE), and several independent agencies.
Date:
January 5, 2010
Creator:
Behrens, Carl E.
System:
The UNT Digital Library
Colombia Adopts Revised Peace Accord: What Next?
This report discusses the Colombian government's revised peace accord, signed in November 2016 by President Juan Manuel Santos and the FARC's leader (known as Timochenko).
Date:
December 5, 2016
Creator:
Beittel, June S.
System:
The UNT Digital Library
NATO's 2018 Brussels Summit
This report discusses the meeting of leaders from the North Atlantic Treaty Organization's (NATO's) 29 member states, scheduled to take place on hold a summit at NATO headquarters in Brussels, Belgium, on July 11-12, 2018. Despite the heightened U.S.-European tensions, NATO officials say they expect the allies to announce new NATO initiatives in six main areas at the summit: enhancing collective defense and deterrence, defense spending and burdensharing, countering terrorism, enhancing NATO cooperation with the European Union, and NATO enlargement.
Date:
July 5, 2018
Creator:
Belkin, Paul
System:
The UNT Digital Library
Low Enriched Uranium Core Design for the Massachusetts Institute of Technology Reactor (MITR) with Un-finned 12 mil-thick Clad UMo Monolithic Fuel
None
Date:
December 5, 2013
Creator:
Bergeron, A.; Wilson, E. H.; Yesilyurt, G.; Dunn, F. D.; Stevens, J. G.; Hu, L. et al.
System:
The UNT Digital Library