Degree Department

79 Matching Results

Results open in a new window/tab.

Recording Session: 2012-02-16 – Éva Polgár, piano

Access: Use of this item is restricted to the UNT Community
Recording Session performed at the UNT College of Voertman Kenton Hall.
Date: February 16, 2012
Creator: Polgár, Éva, 1983-
Object Type: Video
System: The UNT Digital Library
National Nuclear Security Administration: Observations on NNSA's Management and Oversight of the Nuclear Security Enterprise (open access)

National Nuclear Security Administration: Observations on NNSA's Management and Oversight of the Nuclear Security Enterprise

Testimony issued by the Government Accountability Office with an abstract that begins "NNSA has successfully ensured that the nuclear weapons stockpile remains safe and reliable in the absence of underground nuclear testing, accomplishing this complicated task by using state-of-the-art facilities as well as the skills of top scientists. Nevertheless, NNSA does not have reliable enterprise-wide management information on program budgets and costs, which potentially increases risk to NNSA’s programs. For example, in June 2010, GAO reported that NNSA could not identify the total costs to operate and maintain essential weapons activities facilities and infrastructure. In addition, in February 2011, GAO reported that NNSA lacks complete data on, among other things, the condition and value of its existing infrastructure, cost estimates and completion dates for planned capital improvement projects, and critical human capital skills in its contractor workforce that are needed for its programs. As a result, NNSA does not have a sound basis for making decisions on how to most effectively manage its portfolio of projects and other programs and lacks information that could help justify future budget requests or target cost savings opportunities. NNSA recognizes that its ability to make informed decisions is hampered and is taking steps to …
Date: February 16, 2012
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Safety Effects of Less Prescriptive Requirements for Low-Stress Natural Gas Transmission Pipelines Are Uncertain (open access)

Safety Effects of Less Prescriptive Requirements for Low-Stress Natural Gas Transmission Pipelines Are Uncertain

Correspondence issued by the Government Accountability Office with an abstract that begins "Applying PHMSA’s new distribution integrity management requirements to low-stress transmission pipelines would result in less prescriptive safety requirements for these pipelines. Overall, requirements for distribution pipelines are less prescriptive than requirements for transmission pipelines in part because the former operate at lower pressure and pose lower risks in general than the latter. For example, the integrity management regulations for transmission pipelines allow three types of in-depth physical inspections. In contrast, distribution pipeline operators can customize their integrity management programs to the complexity of their systems, including using a broader range of methods for physical inspection. While PHMSA officials stated that “less prescriptive” does not necessarily mean less safe, they also stated that distribution integrity management requirements for distribution pipelines can be more difficult to enforce than integrity management requirements for transmission pipelines. Currently, PHMSA can grant special permits to modify requirements for individual pipelines, if merited, but applying the new distribution integrity management requirements to low-stress transmission pipelines would affect all such pipelines."
Date: February 16, 2012
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Defined Benefit Pension Plans: Recent Developments Highlight Challenges of Hedge Fund and Private Equity Investing (open access)

Defined Benefit Pension Plans: Recent Developments Highlight Challenges of Hedge Fund and Private Equity Investing

A letter report issued by the Government Accountability Office with an abstract that begins "While plan representatives GAO contacted generally stated that their hedge fund and private equity investments met expectations in recent years, a number of plans experienced losses and other challenges, such as limited liquidity and transparency. National data indicated that hedge fund and private equity investments were significantly affected by the 2008-2009 financial crisis, and plans and experts GAO contacted indicated that pension plan investments were not insulated from losses. Most of the 22 plan representatives GAO interviewed said that their hedge fund investments met expectations overall, despite, in some cases, significant losses during the financial crisis. A few plan representatives, however, expected hedge fund investments to be much more resilient in turbulent markets, and found the losses disappointing. Given the long-term nature of private equity investments, almost all of the representatives were generally satisfied with these investments over the last 5 years. Some plan representatives described significant difficulties in hedge fund and private equity investing related to limited liquidity and transparency, and the negative impact of the actions of other investors in the fund—sometimes referred to as co-investors. For example, representatives from one plan reported they …
Date: February 16, 2012
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Workforce Investment Act: Innovative Collaborations between Workforce Boards and Employers Helped Meet Urgent Local Workforce Needs (open access)

Workforce Investment Act: Innovative Collaborations between Workforce Boards and Employers Helped Meet Urgent Local Workforce Needs

Testimony issued by the Government Accountability Office with an abstract that begins "Workforce board officials and their partners in the 14 initiatives cited a range of factors that facilitated building innovative collaborations. Almost all of the collaborations grew out of efforts to address urgent workforce needs of multiple employers in a specific sector, rather than focusing on individual employers. The partners in these initiatives made extra effort to engage employers so they could tailor services such as jobseeker assessment, screening, and training to address specific employer needs. In all the initiatives, partners remained engaged in these collaborations because they continued to produce a wide range of reported results, such as an increased supply of skilled labor, job placements, reduced employer recruitment and turnover costs, and averted layoffs. While these boards were successful in their efforts, they cited some challenges to collaboration that they needed to overcome. Some boards were challenged to develop comprehensive strategies to address diverse employer needs with WIA funds. For example, some boards’ staff said that while their initiatives sought to meet employer needs for higher-skilled workers through skill upgrades, WIA funds can be used to train current workers only in limited circumstances, and the boards used …
Date: February 16, 2012
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Air Traffic Control Modernization: Management Challenges Associated with Program Costs and Schedules Could Hinder NextGen Implementation (open access)

Air Traffic Control Modernization: Management Challenges Associated with Program Costs and Schedules Could Hinder NextGen Implementation

A letter report issued by the Government Accountability Office with an abstract that begins "In a review of 30 major ATC acquisition programs, all of which will contribute to the transition to NextGen, GAO found that costs for 11 of the 30 programs have increased from their initial estimates by a total of $4.2 billion and 15 programs experienced delays. The 11 acquisitions that experienced cost increases account for over 60 percent of FAA’s total acquisition costs ($11 billion of $17.7 billion) for the 30 programs. The 15 acquisitions that experienced schedule delays, of which 10 also had cost increases, ranged from 2 months to more than 14 years and averaged 48 months."
Date: February 16, 2012
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Senate Preservation Fund: Audit of Fiscal Years 2009 and 2010 Transactions (open access)

Senate Preservation Fund: Audit of Fiscal Years 2009 and 2010 Transactions

Correspondence issued by the Government Accountability Office with an abstract that begins "For fiscal years 2009 and 2010, the Fund’s recorded transactions consisted of 136 investment and operating transactions recorded and accounted for by the Library. The Fund’s recorded transactions were authorized in advance, supported by documentation, and accurately accounted for. However, while the Fund’s transactions were generally recorded promptly, we did identify five instances where transactions were not promptly recorded by the Library. We found that all recorded transactions were in compliance with the applicable laws that we deemed significant to the objectives of our audit."
Date: February 16, 2012
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
The Greensheet (Houston, Tex.), Vol. 43, No. 33, Ed. 1 Thursday, February 16, 2012 (open access)

The Greensheet (Houston, Tex.), Vol. 43, No. 33, Ed. 1 Thursday, February 16, 2012

Free weekly newspaper that includes business and classified advertising.
Date: February 16, 2012
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Port Aransas South Jetty (Port Aransas, Tex.), Vol. 41, No. 7, Ed. 1 Thursday, February 16, 2012 (open access)

Port Aransas South Jetty (Port Aransas, Tex.), Vol. 41, No. 7, Ed. 1 Thursday, February 16, 2012

Weekly newspaper from Port Aransas, Texas on Mustang Island that includes local, state and national news along with extensive advertising.
Date: February 16, 2012
Creator: Judson, Mary Henkel
Object Type: Newspaper
System: The Portal to Texas History
The Greensheet (Houston, Tex.), Vol. 43, No. 32, Ed. 1 Thursday, February 16, 2012 (open access)

The Greensheet (Houston, Tex.), Vol. 43, No. 32, Ed. 1 Thursday, February 16, 2012

Free weekly newspaper that includes business and classified advertising.
Date: February 16, 2012
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
AdS/QCD, Light-Front Holography, and Sublimated Gluons (open access)

AdS/QCD, Light-Front Holography, and Sublimated Gluons

The gauge/gravity duality leads to a simple analytical and phenomenologically compelling nonperturbative approximation to the full light-front QCD Hamiltonian - 'Light-Front Holography', which provides a Lorentz-invariant first-approximation to QCD, and successfully describes the spectroscopy of light-quark meson and baryons, their elastic and transition form factors, and other hadronic properties. The bound-state Schroedinger and Dirac equations of the soft-wall AdS/QCD model predict linear Regge trajectories which have the same slope in orbital angular momentum L and radial quantum number n for both mesons and baryons. Light-front holography connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable {zeta} in 3+1 space at fixed light-front time. A key feature is the determination of the frame-independent light-front wavefunctions of hadrons - the relativistic analogs of the Schroedinger wavefunctions of atomic physics which allow one to compute form factors, transversity distributions, spin properties of the valence quarks, jet hadronization, and other hadronic observables. One thus obtains a one-parameter color-confining model for hadron physics at the amplitude level. AdS/QCD also predicts the form of the non-perturbative effective coupling {alpha}{sub s}{sup AdS} (Q) and its {beta}-function with an infrared fixed point which agrees with the effective coupling a{sub g1} (Q{sup 2}) extracted …
Date: February 16, 2012
Creator: Brodsky, Stanley J. & de Teramond, Guy F.
Object Type: Article
System: The UNT Digital Library
CALIBRATION OF X-RAY IMAGING DEVICES FOR ACCURATE INTENSITY MEASUREMENT (open access)

CALIBRATION OF X-RAY IMAGING DEVICES FOR ACCURATE INTENSITY MEASUREMENT

National Security Technologies (NSTec) has developed calibration procedures for X-ray imaging systems. The X-ray sources that are used for calibration are both diode type and diode/fluorescer combinations. Calibrating the X-ray detectors is key to accurate calibration of the X-ray sources. Both energy dispersive detectors and photodiodes measuring total flux were used. We have developed calibration techniques for the detectors using radioactive sources that are traceable to the National Institute of Standards and Technology (NIST). The German synchrotron at Physikalische Technische Bundestalt (PTB) is used to calibrate silicon photodiodes over the energy range from 50 eV to 60 keV. The measurements on X-ray cameras made using the NSTec X-ray sources have included quantum efficiency averaged over all pixels, camera counts per photon per pixel, and response variation across the sensor. The instrumentation required to accomplish the calibrations is described. X-ray energies ranged from 720 eV to 22.7 keV. The X-ray sources produce narrow energy bands, allowing us to determine the properties as a function of X-ray energy. The calibrations were done for several types of imaging devices. There were back illuminated and front illuminated CCD (charge coupled device) sensors, and a CID (charge injection device) type camera. The CCD and CID …
Date: February 16, 2012
Creator: Haugh, M. J.; Charest, M. R.; Ross, P. W.; Lee, J. J.; Schneider, M. B.; Palmer, N. E. et al.
Object Type: Article
System: The UNT Digital Library
Visualization of Target Inspection data at the National Ignition Facility (open access)

Visualization of Target Inspection data at the National Ignition Facility

As the National Ignition Facility continues its campaign to achieve ignition, new methods and tools will be required to measure the quality of the target capsules used to achieve this goal. Techniques have been developed to measure capsule surface features using a phase-shifting diffraction interferometer and Leica Microsystems confocal microscope. These instruments produce multi-gigabyte datasets which consist of tens to hundreds of files. Existing software can handle viewing a small subset of an entire dataset, but none can view a dataset in its entirety. Additionally, without an established mode of transport that keeps the target capsules properly aligned throughout the assembly process, a means of aligning the two dataset coordinate systems is needed. The goal of this project is to develop web based software utilizing WebGL which will provide high level overview visualization of an entire dataset, with the capability to retrieve finer details on demand, in addition to facilitating alignment of multiple datasets with one another based on common features that have been visually identified by users of the system.
Date: February 16, 2012
Creator: Potter, D & Antipa, N
Object Type: Article
System: The UNT Digital Library
Transversity from First Principles in QCD (open access)

Transversity from First Principles in QCD

Transversity observables, such as the T-odd Sivers single-spin asymmetry measured in deep inelastic lepton scattering on polarized protons and the distributions which are measured in deeply virtual Compton scattering, provide important constraints on the fundamental quark and gluon structure of the proton. In this talk I discuss the challenge of computing these observables from first principles; i.e.; quantum chromodynamics, itself. A key step is the determination of the frame-independent light-front wavefunctions (LFWFs) of hadrons - the QCD eigensolutions which are analogs of the Schroedinger wavefunctions of atomic physics. The lensing effects of initial-state and final-state interactions, acting on LFWFs with different orbital angular momentum, lead to T-odd transversity observables such as the Sivers, Collins, and Boer-Mulders distributions. The lensing effect also leads to leading-twist phenomena which break leading-twist factorization such as the breakdown of the Lam-Tung relation in Drell-Yan reactions. A similar rescattering mechanism also leads to diffractive deep inelastic scattering, as well as nuclear shadowing and non-universal antishadowing. It is thus important to distinguish 'static' structure functions, the probability distributions computed the target hadron's light-front wavefunctions, versus 'dynamical' structure functions which include the effects of initial- and final-state rescattering. I also discuss related effects such as the J = …
Date: February 16, 2012
Creator: Brodsky, Stanley J. & /SLAC /Southern Denmark U., CP3-Origins
Object Type: Article
System: The UNT Digital Library
Scale Setting Using the Extended Re normalization Group and the Principle of Maximal Conformality: the QCD Coupling at Four Loops (open access)

Scale Setting Using the Extended Re normalization Group and the Principle of Maximal Conformality: the QCD Coupling at Four Loops

A key problem in making precise perturbative QCD predictions is to set the proper renormalization scale of the running coupling. The extended renormalization group equations, which express the invariance of physical observables under both the renormalization scale- and scheme-parameter transformations, provide a convenient way for estimating the scale- and scheme-dependence of the physical process. In this paper, we present a solution for the scale-equation of the extended renormalization group equations at the four-loop level. Using the principle of maximum conformality (PMC)/Brodsky-Lepage-Mackenzie (BLM) scale-setting method, all non-conformal {beta}{sub i} terms in the perturbative expansion series can be summed into the running coupling, and the resulting scale-fixed predictions are independent of the renormalization scheme. Different schemes lead to different effective PMC/BLM scales, but the final results are scheme independent. Conversely, from the requirement of scheme independence, one not only can obtain scheme-independent commensurate scale relations among different observables, but also determine the scale displacements among the PMC/BLM scales which are derived under different schemes. In principle, the PMC/BLM scales can be fixed order-by-order, and as a useful reference, we present a systematic and scheme-independent procedure for setting PMC/BLM scales up to NNLO. An explicit application for determining the scale setting of R{sub …
Date: February 16, 2012
Creator: Brodsky, Stanley J. & Wu, Xing-Gang
Object Type: Article
System: The UNT Digital Library
Analytic Coleman-de Luccia Geometries (open access)

Analytic Coleman-de Luccia Geometries

We present the necessary and sufficient conditions for a Euclidean scale factor to be a solution of the Coleman-de Luccia equations for some analytic potential V ({psi}), with a Lorentzian continuation describing the growth of a bubble of lower-energy vacuum surrounded by higher-energy vacuum. We then give a set of explicit examples that satisfy the conditions and thus are closed-form analytic examples of Coleman-de Luccia geometries.
Date: February 16, 2012
Creator: Dong, Xi; /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC; Harlow, Daniel & /Stanford U., ITP /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
Elementary Steps of Syngas Reactions on Mo2C(001): Adsorption Thermochemistry and Bond Dissociation (open access)

Elementary Steps of Syngas Reactions on Mo2C(001): Adsorption Thermochemistry and Bond Dissociation

Density functional theory (DFT) and ab initio thermodynamics are applied in order to investigate the most stable surface and subsurface terminations of Mo{sub 2}C(001) as a function of chemical potential and in the presence of syngas. The Mo-terminated (001) surface is then used as a model surface to evaluate the thermochemistry and energetic barriers for key elementary steps in syngas reactions. Adsorption energy scaling relations and Broensted-Evans-Polanyi relationships are established and used to place Mo{sub 2}C into the context of transition metal surfaces. The results indicate that the surface termination is a complex function of reaction conditions and kinetics. It is predicted that the surface will be covered by either C{sub 2}H{sub 2} or O depending on conditions. Comparisons to transition metals indicate that the Mo-terminated Mo{sub 2}C(001) surface exhibits carbon reactivity similar to transition metals such as Ru and Ir, but is significantly more reactive towards oxygen.
Date: February 16, 2012
Creator: Medford, Andrew
Object Type: Article
System: The UNT Digital Library
Building Cooling and Air Conditioning (open access)

Building Cooling and Air Conditioning

Advanced Research Projects Agency-Energy project sheet summarizing general information about the 15 projects that are a part of the Building Energy Efficiency Through Innovative Thermodevices (BEETIT) program including project goals, innovation needs, and potential impacts.
Date: February 16, 2012
Creator: United States. Advanced Research Projects Agency-Energy.
Object Type: Text
System: The UNT Digital Library
ADVANCED COMPOSITE WIND TURBINE BLADE DESIGN BASED ON DURABILITY AND DAMAGE TOLERANCE (open access)

ADVANCED COMPOSITE WIND TURBINE BLADE DESIGN BASED ON DURABILITY AND DAMAGE TOLERANCE

The objective of the program was to demonstrate and verify Certification-by-Analysis (CBA) capability for wind turbine blades made from advanced lightweight composite materials. The approach integrated durability and damage tolerance analysis with robust design and virtual testing capabilities to deliver superior, durable, low weight, low cost, long life, and reliable wind blade design. The GENOA durability and life prediction software suite was be used as the primary simulation tool. First, a micromechanics-based computational approach was used to assess the durability of composite laminates with ply drop features commonly used in wind turbine applications. Ply drops occur in composite joints and closures of wind turbine blades to reduce skin thicknesses along the blade span. They increase localized stress concentration, which may cause premature delamination failure in composite and reduced fatigue service life. Durability and damage tolerance (D&DT) were evaluated utilizing a multi-scale micro-macro progressive failure analysis (PFA) technique. PFA is finite element based and is capable of detecting all stages of material damage including initiation and propagation of delamination. It assesses multiple failure criteria and includes the effects of manufacturing anomalies (i.e., void, fiber waviness). Two different approaches have been used within PFA. The first approach is Virtual Crack Closure Technique …
Date: February 16, 2012
Creator: Abumeri, Galib & Abdi, Frank
Object Type: Report
System: The UNT Digital Library
NEAMS Update. Quarterly Report for October - December 2011. (open access)

NEAMS Update. Quarterly Report for October - December 2011.

The Advanced Modeling and Simulation Office within the DOE Office of Nuclear Energy (NE) has been charged with revolutionizing the design tools used to build nuclear power plants during the next 10 years. To accomplish this, the DOE has brought together the national laboratories, U.S. universities, and the nuclear energy industry to establish the Nuclear Energy Advanced Modeling and Simulation (NEAMS) Program. The mission of NEAMS is to modernize computer modeling of nuclear energy systems and improve the fidelity and validity of modeling results using contemporary software environments and high-performance computers. NEAMS will create a set of engineering-level codes aimed at designing and analyzing the performance and safety of nuclear power plants and reactor fuels. The truly predictive nature of these codes will be achieved by modeling the governing phenomena at the spatial and temporal scales that dominate the behavior. These codes will be executed within a simulation environment that orchestrates code integration with respect to spatial meshing, computational resources, and execution to give the user a common 'look and feel' for setting up problems and displaying results. NEAMS is building upon a suite of existing simulation tools, including those developed by the federal Scientific Discovery through Advanced Computing and …
Date: February 16, 2012
Creator: Bradley, K. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Emergent Phenomena at Oxide Interfaces (open access)

Emergent Phenomena at Oxide Interfaces

Transition metal oxides (TMOs) are an ideal arena for the study of electronic correlations because the s-electrons of the transition metal ions are removed and transferred to oxygen ions, and hence the strongly correlated d-electrons determine their physical properties such as electrical transport, magnetism, optical response, thermal conductivity, and superconductivity. These electron correlations prohibit the double occupancy of metal sites and induce a local entanglement of charge, spin, and orbital degrees of freedom. This gives rise to a variety of phenomena, e.g., Mott insulators, various charge/spin/orbital orderings, metal-insulator transitions, multiferroics, and superconductivity. In recent years, there has been a burst of activity to manipulate these phenomena, as well as create new ones, using oxide heterostructures. Most fundamental to understanding the physical properties of TMOs is the concept of symmetry of the order parameter. As Landau recognized, the essence of phase transitions is the change of the symmetry. For example, ferromagnetic ordering breaks the rotational symmetry in spin space, i.e., the ordered phase has lower symmetry than the Hamiltonian of the system. There are three most important symmetries to be considered here. (i) Spatial inversion (I), defined as r {yields} -r. In the case of an insulator, breaking this symmetry can …
Date: February 16, 2012
Creator: Hwang, H.Y.
Object Type: Report
System: The UNT Digital Library
The Greensheet (Fort Worth, Tex.), Vol. 35, No. 320, Ed. 1 Thursday, February 16, 2012 (open access)

The Greensheet (Fort Worth, Tex.), Vol. 35, No. 320, Ed. 1 Thursday, February 16, 2012

Free weekly newspaper that includes business and classified advertising.
Date: February 16, 2012
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Greensheet (Austin, Tex.), Vol. 35, No. 2, Ed. 1 Thursday, February 16, 2012 (open access)

The Greensheet (Austin, Tex.), Vol. 35, No. 2, Ed. 1 Thursday, February 16, 2012

Free weekly newspaper that includes business and classified advertising.
Date: February 16, 2012
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Greensheet (Arlington-Grand Prairie, Tex.), Vol. 35, No. 318, Ed. 1 Thursday, February 16, 2012 (open access)

The Greensheet (Arlington-Grand Prairie, Tex.), Vol. 35, No. 318, Ed. 1 Thursday, February 16, 2012

Free weekly newspaper that includes business and classified advertising.
Date: February 16, 2012
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History