Where the Sidewalk Ends: Jets and Missing Energy Search Strategies for the 7 TeV LHC (open access)

Where the Sidewalk Ends: Jets and Missing Energy Search Strategies for the 7 TeV LHC

This work explores the potential reach of the 7 TeV LHC to new colored states in the context of simplified models and addresses the issue of which search regions are necessary to cover an extensive set of event topologies and kinematic regimes. This article demonstrates that if searches are designed to focus on specific regions of phase space, then new physics may be missed if it lies in unexpected corners. Simple multiregion search strategies can be designed to cover all of kinematic possibilities. A set of benchmark models are created that cover the qualitatively different signatures and a benchmark multiregion search strategy is presented that covers these models.
Date: August 15, 2011
Creator: Alves, Daniele S.M.; Izaguirre, Eder; Wacker, Jay G. & /SLAC /Stanford U., ITP
Object Type: Article
System: The UNT Digital Library
Nanosensors as Reservoir Engineering Tools to Map Insitu Temperature Distributions in Geothermal Reservoirs (open access)

Nanosensors as Reservoir Engineering Tools to Map Insitu Temperature Distributions in Geothermal Reservoirs

The feasibility of using nanosensors to measure temperature distribution and predict thermal breakthrough in geothermal reservoirs is addressed in this report. Four candidate sensors were identified: melting tin-bismuth alloy nanoparticles, silica nanoparticles with covalently-attached dye, hollow silica nanoparticles with encapsulated dye and impermeable melting shells, and dye-polymer composite time-temperature indicators. Four main challenges associated with the successful implementation of temperature nanosensors were identified: nanoparticle mobility in porous and fractured media, the collection and detection of nanoparticles at the production well, engineering temperature sensing mechanisms that are both detectable and irreversible, and inferring the spatial geolocation of temperature measurements in order to map temperature distribution. Initial experiments were carried out to investigate each of these challenges. It was demonstrated in a slim-tube injection experiment that it is possible to transport silica nanoparticles over large distances through porous media. The feasibility of magnetic collection of nanoparticles from produced fluid was evaluated experimentally, and it was estimated that 3% of the injected nanoparticles were recovered in a prototype magnetic collection device. An analysis technique was tailored to nanosensors with a dye-release mechanism to estimate temperature measurement geolocation by analyzing the return curve of the released dye. This technique was used in a hypothetical …
Date: June 15, 2011
Creator: Ames, Morgan.
Object Type: Report
System: The UNT Digital Library
Federal Agency Authority to Contract for Electric Power and Renewable Energy Supply (open access)

Federal Agency Authority to Contract for Electric Power and Renewable Energy Supply

None
Date: August 15, 2011
Creator: Andrews, Anthony
Object Type: Report
System: The UNT Digital Library
Recent Developments in SHERPA (open access)

Recent Developments in SHERPA

Some recent QCD-related developments in the SHERPA event generator are presented. In the past decades, event generators such as PYTHIA [1, 2] and HERWIG [3, 4] have been central for nearly all physics analyses at particle physics experiments at the high-energy frontier. This will also hold true at the LHC, where a large number of interesting signals for new particles or new phenomena (the Higgs boson or any other manifestation of the mechanism behind electro-weak symmetry breaking, supersymmetry, extra dimensions etc.) is hampered by a plethora of severe, sometimes overwhelming backgrounds. Nearly all of them are largely influenced by QCD. Therefore it seems fair to say that the success of the LHC in finding new physics may very well depend on a deep and detailed understanding of old physics, like QCD. Examples for this include, among others, the central-jet veto for the vector boson fusion channel for Higgs production or topologies, where gauge bosons emerge in association with many jets, a background for many search channels. In a reflection on increased needs by the experimental community, aiming at higher precision, incorporation of new physics models and so on, the work horses of old have undergone serious renovation efforts, resulting in …
Date: November 15, 2011
Creator: Archibald, Jennifer; Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank; Schonherr, Marek; Schumann, Steffen et al.
Object Type: Article
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: February 15, 2011
Creator: Arieff, Alexis
Object Type: Report
System: The UNT Digital Library
U.S. Department of Energy Clean Cities Five-Year Strategic Plan (open access)

U.S. Department of Energy Clean Cities Five-Year Strategic Plan

Clean Cities is a government-industry partnership sponsored by the U.S. Department of Energy's (DOE) Vehicle Technologies Program, which is part of the Office of Energy Efficiency and Renewable Energy. Working with its network of about 100 local coalitions and more than 6,500 stakeholders across the country, Clean Cities delivers on its mission to reduce petroleum consumption in on-road transportation. In its work to reduce petroleum use, Clean Cities focuses on a portfolio of technologies that includes electric drive, propane, natural gas, renewable natural gas/biomethane, ethanol/E85, biodiesel/B20 and higher-level blends, fuel economy, and idle reduction. Over the past 17 years, Clean Cities coalitions have displaced more than 2.4 billion gallons of petroleum; they are on track to displace 2.5 billion gallons of gasoline per year by 2020. This Clean Cities Strategic Plan lays out an aggressive five-year agenda to help DOE Clean Cities and its network of coalitions and stakeholders accelerate the deployment of alternative fuel and advanced technology vehicles, while also expanding the supporting infrastructure to reduce petroleum use. Today, Clean Cities has a far larger opportunity to make an impact than at any time in its history because of its unprecedented $300 million allocation for community-based deployment projects from …
Date: February 15, 2011
Creator: Associates, Cambridge Concord
Object Type: Report
System: The UNT Digital Library
Improving the Top Quark Forward-Backward Asymmetry Measurement at the LHC (open access)

Improving the Top Quark Forward-Backward Asymmetry Measurement at the LHC

At the LHC, top quark pairs are dominantly produced from gluons, making it difficult to measure the top quark forward-backward asymmetry. To improve the asymmetry measurement, we study variables that can distinguish between top quarks produced from quarks and those from gluons: the invariant mass of the top pair, the rapidity of the top-antitop system in the lab frame, the rapidity of the top quark in the top-antitop rest frame, the top quark polarization and the top-antitop spin correlation. We combine all the variables in a likelihood discriminant method to separate quark-initiated events from gluon-initiated events. We apply our method on models including G-prime's and W-prime's motivated by the recent observation of a large top quark forward-backward asymmetry at the Tevatron. We have found that the significance of the asymmetry measurement can be improved by 10% to 30%. At the same time, the central values of the asymmetry increase by 40% to 100%. We have also analytically derived the best spin quantization axes for studying top quark polarization as well as spin-correlation for the new physics models.
Date: August 15, 2011
Creator: Bai, Yang & Han, Zhenyu
Object Type: Article
System: The UNT Digital Library
A Piecewise Linear Discontinuous Finite Element Spatial Discretization of the Sn Transport Equation for Polyhedral Grids in 3D Cartesian Geometry (open access)

A Piecewise Linear Discontinuous Finite Element Spatial Discretization of the Sn Transport Equation for Polyhedral Grids in 3D Cartesian Geometry

None
Date: August 15, 2011
Creator: Bailey, T S; Hawkins, W D & Adams, M L
Object Type: Article
System: The UNT Digital Library
Genetic manipulation of the obligate chemolithoautotrophic bacterium Thiobacillus denitrificans (open access)

Genetic manipulation of the obligate chemolithoautotrophic bacterium Thiobacillus denitrificans

Chemolithoautotrophic bacteria can be of industrial and environmental importance, but they present a challenge for systems biology studies, as their central metabolism deviates from that of model organisms and there is a much less extensive experimental basis for their gene annotation than for typical organoheterotrophs. For microbes with sequenced genomes but unconventional metabolism, the ability to create knockout mutations can be a powerful tool for functional genomics and thereby render an organism more amenable to systems biology approaches. In this chapter, we describe a genetic system for Thiobacillus denitrificans, with which insertion mutations can be introduced by homologous recombination and complemented in trans. Insertion mutations are generated by in vitro transposition, the mutated genes are amplified by the PCR, and the amplicons are introduced into T. denitrificans by electroporation. Use of a complementation vector, pTL2, based on the IncP plasmid pRR10 is also addressed.
Date: July 15, 2011
Creator: Beller, H.R.; Legler, T.C. & Kane, S.R.
Object Type: Article
System: The UNT Digital Library
OpenMP for Accelerators (open access)

OpenMP for Accelerators

OpenMP [13] is the dominant programming model for shared-memory parallelism in C, C++ and Fortran due to its easy-to-use directive-based style, portability and broad support by compiler vendors. Similar characteristics are needed for a programming model for devices such as GPUs and DSPs that are gaining popularity to accelerate compute-intensive application regions. This paper presents extensions to OpenMP that provide that programming model. Our results demonstrate that a high-level programming model can provide accelerated performance comparable to hand-coded implementations in CUDA.
Date: March 15, 2011
Creator: Beyer, J C; Stotzer, E J; Hart, A & de Supinski, B R
Object Type: Article
System: The UNT Digital Library
American Jihadist Terrorism: Combating a Complex Threat (open access)

American Jihadist Terrorism: Combating a Complex Threat

This report describes homegrown violent jihadists and the plots and attacks that have occurred since 9/11. For this report, "homegrown" and "domestic" are terms that describe terrorist activity or plots perpetrated within the United States or abroad by American citizens, legal permanent residents, or visitors radicalized largely within the United States. The report also discusses the radicalization process and the forces driving violent extremist activity. It analyzes post-9/11 domestic jihadist terrorism and describes law enforcement and intelligence efforts to combat terrorism and the challenges associated with those efforts. It also outlines actions underway to build trust and partnership between community groups and government agencies and the tensions that may occur between law enforcement and engagement activities.
Date: November 15, 2011
Creator: Bjelopera, Jerome P.
Object Type: Report
System: The UNT Digital Library
The U.N. Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW): Issues in the U.S. Ratification Debate (open access)

The U.N. Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW): Issues in the U.S. Ratification Debate

This report provides an overview of the Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW) and describes its background, objectives, and structure, including the role of the Convention's monitoring body, the CEDAW Committee. It examines U.S. policy and issues in the U.S. ratification debate, including the Convention's possible impact on U.S. sovereignty, its effectiveness in combating discrimination, and its role as an instrument of U.S. foreign policy.
Date: April 15, 2011
Creator: Blanchfield, Luisa
Object Type: Report
System: The UNT Digital Library
The United Nations Human Rights Council: Issues for Congress (open access)

The United Nations Human Rights Council: Issues for Congress

This report provides historical background of the Council, including the role of the previous Commission. It discusses the Council's current mandate and structures, as well as U.S. policy and congressional actions. Finally, it highlights possible policy issues for the 112th Congress, including the overall effectiveness of the Council in addressing human rights, implications for U.S. membership, and U.S. financial contributions to the Council.
Date: November 15, 2011
Creator: Blanchfield, Luisa
Object Type: Report
System: The UNT Digital Library
New Prospects in High Energy Astrophysics (open access)

New Prospects in High Energy Astrophysics

Recent discoveries using TeV, X-ray and radio telescopes as well as Ultra High Energy Cosmic Ray arrays are leading to new insights into longstanding puzzles in high energy astrophysics. Many of these insights come from combining observations throughout the electromagnetic and other spectra as well as evidence assembled from different types of source to propose general principles. Issues discussed in this general overview include methods of accelerating relativistic particles, and amplifying magnetic field, the dynamics of relativistic outflows and the nature of the prime movers that power them. Observational approaches to distinguishing hadronic, leptonic and electromagnetic outflows and emission mechanisms are discussed along with probes of the velocity field and the confinement mechanisms. Observations with GLAST promise to be very prescriptive for addressing these problems.
Date: November 15, 2011
Creator: Blandford, Roger
Object Type: Article
System: The UNT Digital Library
Implementation and Performance of the Tau Trigger in the ATLAS Experiment (open access)

Implementation and Performance of the Tau Trigger in the ATLAS Experiment

Triggering on hadronic taus at the LHC is a difficult task due to the high rate and occupancy of the events. On the other hand, the tau trigger increases the discovery potential of ATLAS in many physics channels, among others the Standard Model or SuperSymmetric Higgs (charged or neutrals) production. In order to cope with the rate and optimize the efficiency on important physics channels, the results of the current simulation studies indicate that the ATLAS tau trigger should be used either with relatively high transverse momentum thresholds alone, or with more relaxed threshold requirements in combination with other triggers, like the missing transverse energy trigger or a leptonic or jet trigger. In this contribution we describe the ATLAS tau trigger, and we present some of the current results from the simulation studies, focusing both on early physics and on physics at high luminosity.
Date: November 15, 2011
Creator: Bosman, M.; Casado, P.; /Barcelona, IFAE; Dam, M.; U., /Copenhagen; Demers, S. et al.
Object Type: Article
System: The UNT Digital Library
Experimental Investigation of Excited-State Lifetimes in Atomic Ytterbium (open access)

Experimental Investigation of Excited-State Lifetimes in Atomic Ytterbium

Lifetimes of 21 excited states in atomic Yb were measured using time-resolved fluorescence detection following pulsed laser excitation. The lifetime of the 4f{sup 14}5d6s {sup 3}D{sub 1} state, which is of particular importance for a proposed study of parity nonconservation in atoms, was measured to be 380(30) ns.
Date: November 15, 2011
Creator: Bowers, C. J.; Budker, D.; Commins, E. D.; DeMille, D.; Freedman, S. J.; Nguyen, A. -T. et al.
Object Type: Article
System: The UNT Digital Library
Warm Water Oxidation Verification - Scoping and Stirred Reactor Tests (open access)

Warm Water Oxidation Verification - Scoping and Stirred Reactor Tests

Scoping tests to evaluate the effects of agitation and pH adjustment on simulant sludge agglomeration and uranium metal oxidation at {approx}95 C were performed under Test Instructions(a,b) and as per sections 5.1 and 5.2 of this Test Plan prepared by AREVA. (c) The thermal testing occurred during the week of October 4-9, 2010. The results are reported here. For this testing, two uranium-containing simulant sludge types were evaluated: (1) a full uranium-containing K West (KW) container sludge simulant consisting of nine predominant sludge components; (2) a 50:50 uranium-mole basis mixture of uraninite [U(IV)] and metaschoepite [U(VI)]. This scoping study was conducted in support of the Sludge Treatment Project (STP) Phase 2 technology evaluation for the treatment and packaging of K-Basin sludge. The STP is managed by CH2M Hill Plateau Remediation Company (CHPRC) for the U.S. Department of Energy. Warm water ({approx}95 C) oxidation of sludge, followed by immobilization, has been proposed by AREVA and is one of the alternative flowsheets being considered to convert uranium metal to UO{sub 2} and eliminate H{sub 2} generation during final sludge disposition. Preliminary assessments of warm water oxidation have been conducted, and several issues have been identified that can best be evaluated through laboratory …
Date: June 15, 2011
Creator: Braley, Jenifer C.; Sinkov, Sergey I.; Delegard, Calvin H. & Schmidt, Andrew J.
Object Type: Report
System: The UNT Digital Library
Improving the phase stability and oxidation resistance of B-NiAl (open access)

Improving the phase stability and oxidation resistance of B-NiAl

High temperature alloys are essential to many industries that require a stable material to perform in harsh oxidative environments. Many of these alloys are suited for specific applications such as jet engine turbine blades where most other materials would either melt or oxidize and crumble (1). These alloys must have a high melting temperature, excellent oxidation resistance, good creep resistance, and decent fracture toughness to be successfully used in such environments. The discovery of Ni based superalloys in the 1940s revolutionized the high temperature alloy industry and there has been continued development of these alloys since their advent (2). These materials are capable of operating in oxidative environments in the presence of combustion gases, water vapor and at temperatures around 1050 C. Demands for increased f uel efficiency, however, has highlighted the need for materials that can be used under similar atmospheres and at temperatures in excess of 1200 C. The current Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that result in softening of the alloys above 1000 C. Therefore, recent research has been aimed at exploring and developing newer alloy systems that can meet the escalating requirements. …
Date: August 15, 2011
Creator: Brammer, Travis
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Evaluation of sustained release polylactate electron donors for removal of hexavalent chromium from contaminated groundwater (open access)

Evaluation of sustained release polylactate electron donors for removal of hexavalent chromium from contaminated groundwater

To evaluate the efficacy of bioimmobilization of Cr(VI) in groundwater at the Department of Energy Hanford site, we conducted a series of microcosm experiments using a range of commercial electron donors with varying degrees of lactate polymerization (polylactate). These experiments were conducted using Hanford Formation sediments (coarse sand and gravel) immersed in Hanford groundwater, which were amended with Cr(VI) and several types of lactate-based electron donors (Hydrogen Release Compound, HRC; primer-HRC, pHRC; extended release HRC) and the polylactate-cysteine form (Metal Remediation Compound, MRC). The results showed that polylactate compounds stimulated an increase in bacterial biomass and activity to a greater extent than sodium lactate when applied at equivalent carbon concentrations. At the same time, concentrations of headspace hydrogen and methane increased and correlated with changes in the microbial community structure. Enrichment of Pseudomonas spp. occurred with all lactate additions, and enrichment of sulfate-reducing Desulfosporosinus spp. occurred with almost complete sulfate reduction. The results of these experiments demonstrate that amendment with the pHRC and MRC forms result in effective removal of Cr(VI) from solution most likely by both direct (enzymatic) and indirect (microbially generated reductant) mechanisms.
Date: February 15, 2011
Creator: Brodie, E. L.; Joyner, D. C.; Faybishenko, B.; Conrad, M. E.; Rios-Velazquez, C.; Mork, B. et al.
Object Type: Article
System: The UNT Digital Library
Recent Developments in Dynamic Transmission Electron Microscopy (open access)

Recent Developments in Dynamic Transmission Electron Microscopy

None
Date: April 15, 2011
Creator: Browning, N D; Bonds, M A; Campbell, G H; Evans, J E; LaGrange, T; Jungjohann, K L et al.
Object Type: Article
System: The UNT Digital Library
Legislative Branch: FY2012 Appropriations (open access)

Legislative Branch: FY2012 Appropriations

This report gives an overview of the status of FY2012 appropriations and funding issues for the Senate, House of Representatives, and support agencies.
Date: June 15, 2011
Creator: Brudnick, Ida A.
Object Type: Report
System: The UNT Digital Library
Effects of Radiation from Fukushima Daiichi on the U.S. Marine Environment (open access)

Effects of Radiation from Fukushima Daiichi on the U.S. Marine Environment

The massive Tohoku earthquake and tsunami of March 11, 2011, caused extensive damage in northeastern Japan, including damage to the Fukushima Dai-ichi nuclear power installation, which resulted in the release of radiation. This report discusses concerns which have arisen about the potential effects of this released radiation on the U.S. marine environment and resources.
Date: April 15, 2011
Creator: Buck, Eugene H. & Upton, Harold F.
Object Type: Report
System: The UNT Digital Library
Asian Carp and the Great Lakes Region (open access)

Asian Carp and the Great Lakes Region

Four species of non-indigenous Asian carp are expanding their range in U.S. waterways, resulting in a variety of concerns and problems. This report details the environmental and economic threats from this invasion, as well as ways to combat the spread of Asian carp in U.S. water.
Date: April 15, 2011
Creator: Buck, Eugene H.; Upton, Harold F.; Stern, Charles V. & Brown, Cynthia
Object Type: Report
System: The UNT Digital Library
2011 Organometallic Chemistry (July 10-15, 2011, Salve Regina University, Newport, RI) (open access)

2011 Organometallic Chemistry (July 10-15, 2011, Salve Regina University, Newport, RI)

Organometallic chemistry has played and will continue to play a significant role in helping us understand the way bonds are made or broken in the presence of a transition metal complex. Current challenges range from the efficient exploitation of energy resources to the creative use of natural and artificial enzymes. Most of the new advances in the area are due to our extended understanding of processes at a molecular level due to new mechanistic studies, techniques to detect reaction intermediates and theory. The conference will bring the most recent advances in the field including nanocatalysis, surface organometallic chemistry, characterization techniques, new chemical reactivity and theoretical approaches along with applications to organic synthesis and the discovery of new materials. The Conference will bring together a collection of investigators who are at the forefront of their field, and will provide opportunities for junior scientists and graduate students to present their work in poster format and exchange ideas with leaders in the field. Six outstanding posters will be selected for short talks. The collegial atmosphere of this Conference, with programmed discussion sessions as well as opportunities for informal gatherings in the afternoons and evenings, provides an avenue for scientists from different disciplines to …
Date: July 15, 2011
Creator: Bunel, Dr. Emilio
Object Type: Article
System: The UNT Digital Library