Partner
UNT Libraries Special Collections
457
UNT Libraries Government Documents Department
230
UNT Libraries
42
Oklahoma Historical Society
27
UNT Music Library
26
Sterling Municipal Library
8
Brownwood Public Library
7
Ennis Public Library
7
San Antonio Public Library
6
Sweetwater/Nolan County City-County Library
6
57 More
Collection
The Black Academy of Arts and Letters Records
417
Texas Digital Newspaper Program
146
Office of Scientific & Technical Information Technical Reports
129
Congressional Research Service Reports
66
Tocker Foundation Grant
54
The Greensheet
31
Oklahoma Digital Newspaper Program
30
Government Accountability Office Reports
27
College of Music Recordings
25
Multicultural Center Records
16
94 More
Degree Department
Degree Discipline
Degree Level
States
Year
Month
Day
Results:
1 - 24 of
900
next
Electron Charged Graphite-based Hydrogen Storage Material
The electron-charge effects have been demonstrated to enhance hydrogen storage capacity using materials which have inherent hydrogen storage capacities. A charge control agent (CCA) or a charge transfer agent (CTA) was applied to the hydrogen storage material to reduce internal discharge between particles in a Sievert volumetric test device. GTI has tested the device under (1) electrostatic charge mode; (2) ultra-capacitor mode; and (3) metal-hydride mode. GTI has also analyzed the charge distribution on storage materials. The charge control agent and charge transfer agent are needed to prevent internal charge leaks so that the hydrogen atoms can stay on the storage material. GTI has analyzed the hydrogen fueling tank structure, which contains an air or liquid heat exchange framework. The cooling structure is needed for hydrogen fueling/releasing. We found that the cooling structure could be used as electron-charged electrodes, which will exhibit a very uniform charge distribution (because the cooling system needs to remove heat uniformly). Therefore, the electron-charge concept does not have any burden of cost and weight for the hydrogen storage tank system. The energy consumption for the electron-charge enhancement method is quite low or omitted for electrostatic mode and ultra-capacitor mode in comparison of other hydrogen storage …
Date:
March 14, 2012
Creator:
0812, Dr. Chinbay Q. Fan R&D Manager Office of Technology and Innovations Phone: 847 768
Object Type:
Report
System:
The UNT Digital Library
Observation of Supernova Remnant IC 443 with the Fermi Large Area Telescope
None
Date:
December 14, 2012
Creator:
Abdo, A. A.
Object Type:
Report
System:
The UNT Digital Library
Insights Into the High-Energy Gamma-Ray Emission of Markarian 501 From Extensive Multifrequency Observations in the Fermi Era
None
Date:
June 14, 2012
Creator:
Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J. et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the Cosmic Ray e+ plus e- Spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2 m{sup 2}sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient electron detection strategy which provides sufficient background rejection for measurement of the steeply-falling electron spectrum up to 1 TeV. Our high precision data show that the electron spectrum falls with energy as E{sup -3.0} and does not exhibit prominent spectral features. Interpretations in terms of a conventional diffusive model as well as a potential local extra component are briefly discussed.
Date:
May 14, 2012
Creator:
Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. et al.
Object Type:
Article
System:
The UNT Digital Library
Observation of Two-Neutrino Double-Beta Decay in Xe-136 with EXO-200
We report the observation of two-neutrino double-beta decay in {sup 136}Xe with T{sub 1/2} = 2.11 {+-} 0.04(stat) {+-} 0.21(syst) x 10{sup 21} yr. This second-order process, predicted by the standard model, has been observed for several nuclei but not for {sup 136}Xe. The observed decay rate provides new input to matrix element calculations and to the search for the more interesting neutrinoless double-beta decay, the most sensitive probe for the existence of Majorana particles and the measurement of the neutrino mass scale.
Date:
September 14, 2012
Creator:
Ackerman, N.; Aharmim, B.; Auger, M.; Auty, D. J.; Barbeau, P. S.; Barry, K. et al.
Object Type:
Article
System:
The UNT Digital Library
Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope
Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 10{sup -26} cm{sup 3} s{sup -1} at 5 GeV to about 5 x 10{sup -23} cm{sup 3} s{sup -1} at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section ({approx}3 x 10{sup -26} cm{sup 3} s{sup -1} for a purely s-wave cross section), without assuming additional boost factors.
Date:
September 14, 2012
Creator:
Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J. et al.
Object Type:
Article
System:
The UNT Digital Library
Constraints on Dark Matter Annihilation in Clusters of Galaxies with the Fermi Large Area Telescope
None
Date:
December 14, 2012
Creator:
Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G. et al.
Object Type:
Article
System:
The UNT Digital Library
Gravitomagnetism and Spinor Quantum Mechanics
We give a systematic treatment of a spin 1=2 particle in a combined electromagnetic field and a weak gravitational field that is produced by a slowly moving matter source. This paper continues previous work on a spin zero particle, but it is largely self-contained and may serve as an introduction to spinors in a Riemann space. The analysis is based on the Dirac equation expressed in generally covariant form and coupled minimally to the electromagnetic field. The restriction to a slowly moving matter source, such as the earth, allows us to describe the gravitational field by a gravitoelectric (Newtonian) potential and a gravitomagnetic (frame-dragging) vector potential, the existence of which has recently been experimentally verified. Our main interest is the coupling of the orbital and spin angular momenta of the particle to the gravitomagnetic field. Specifically we calculate the gravitational gyromagnetic ratio as g{sub g} = 1 ; this is to be compared with the electromagnetic gyromagnetic ratio of g{sub e} = 2 for a Dirac electron.
Date:
September 14, 2012
Creator:
Adler, Ronald J.; /Stanford U., HEPL /San Francisco State U.; Chen, Pisin; /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC; Varani, Elisa & /Unlisted
Object Type:
Article
System:
The UNT Digital Library
Fermi Large Area Telescope Observations of the Supernova Remnant G8.7-0.1
We present a detailed analysis of the GeV gamma-ray emission toward the supernova remnant (SNR) G8.7-0.1 with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. An investigation of the relationship between G8.7-0.1 and the TeV unidentified source HESS J1804-216 provides us with an important clue on diffusion process of cosmic rays if particle acceleration operates in the SNR. The GeV gamma-ray emission is extended with most of the emission in positional coincidence with the SNR G8.7-0.1 and a lesser part located outside the western boundary of G8.7-0.1. The region of the gamma-ray emission overlaps spatially connected molecular clouds, implying a physical connection for the gamma-ray structure. The total gamma-ray spectrum measured with LAT from 200 MeV-100 GeV can be described by a broken power-law function with a break of 2.4 {+-} 0.6 (stat) {+-} 1.2 (sys) GeV, and photon indices of 2.10 {+-} 0.06 (stat) {+-} 0.10 (sys) below the break and 2.70 {+-} 0.12 (stat) {+-} 0.14 (sys) above the break. Given the spatial association among the gamma rays, the radio emission of G8.7-0.1, and the molecular clouds, the decay of p0s produced by particles accelerated in the SNR and hitting the molecular clouds naturally …
Date:
September 14, 2012
Creator:
Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Ensemble: 2012-04-14 – 15th Annual African Cultural Festival
Access:
Use of this item is restricted to the UNT Community
Annual African Cultural Festival concert performed at the UNT College of Music Voertman Hall.
Date:
April 14, 2012
Creator:
Alorwoyie, Gideon Foli
Object Type:
Video
System:
The UNT Digital Library
Ensemble: 2012-04-14 – 15th Annual African Cultural Festival
Access:
Use of this item is restricted to the UNT Community
15th Annual African Cultural Festival concert performed at the UNT College of Music Voertman Hall.
Date:
April 14, 2012
Creator:
Alorwoyie, Gideon Foli
Object Type:
Sound
System:
The UNT Digital Library
Enhancing the Sensitivity to New Physics in the top-antitop Invariant Mass Distribution
We propose selection cuts on the LHC t{bar t} production sample which should enhance the sensitivity to New Physics signals in the study of the t{bar t} invariant mass distribution. We show that selecting events in which the t{bar t} object has little transverse and large longitudinal momentum enlarges the quark-fusion fraction of the sample and therefore increases its sensitivity to New Physics which couples to quarks and not to gluons. We find that systematic error bars play a fundamental role and assume a simple model for them. We check how a non-visible new particle would become visible after the selection cuts enhance its resonance bump. A final realistic analysis should be done by the experimental groups with a correct evaluation of the systematic error bars.
Date:
June 14, 2012
Creator:
Alvarez, Ezequiel & /SLAC, /Univ. Nacional San Luis
Object Type:
Article
System:
The UNT Digital Library
Higgs, Binos and Gluinos: Split Susy within Reach
Recent results from the LHC for the Higgs boson with mass between 142 GeV {approx}< m{sub h{sup 0}} {approx}< 147 GeV points to PeV-scale Split Supersymmetry. This article explores the consequences of a Higgs mass in this range and possible discovery modes for Split Susy. Moderate lifetime gluinos, with decay lengths in the 25 {micro}m to 10 yr range, are its imminent smoking gun signature. The 7TeV LHC will be sensitive to the moderately lived gluinos and trilepton signatures from direct electroweakino production. Moreover, the dark matter abundance may be obtained from annihilation through an s-channel Higgs resonance, with the LSP almost purely bino and mass m{sub {chi}{sub 1}{sup 0}} {approx_equal} 70 GeV. The Higgs resonance region of Split Susy has visible signatures in dark matter direct and indirect detection and electric dipole moment experiments. If the anomalies go away, the majority of Split Susy parameter space will be excluded.
Date:
September 14, 2012
Creator:
Alves, Daniele S.M.; Izaguirre, Eder; /SLAC /Stanford U., Phys. Dept.; Wacker, Jay G. & /SLAC /Stanford U., ITP
Object Type:
Article
System:
The UNT Digital Library
Multi-layer predictive control for tomographic wavefront estimation
None
Date:
March 14, 2012
Creator:
Ammons, S. M.; Johnson, L.; Kupke, R.; Gavel, D.; Max, C. & Poyneer, L.
Object Type:
Article
System:
The UNT Digital Library
Multiscale framework for predicting the coupling between deformation and fluid diffusion in porous rocks
In this project, a predictive multiscale framework will be developed to simulate the strong coupling between solid deformations and fluid diffusion in porous rocks. We intend to improve macroscale modeling by incorporating fundamental physical modeling at the microscale in a computationally efficient way. This is an essential step toward further developments in multiphysics modeling, linking hydraulic, thermal, chemical, and geomechanical processes. This research will focus on areas where severe deformations are observed, such as deformation bands, where classical phenomenology breaks down. Multiscale geometric complexities and key geomechanical and hydraulic attributes of deformation bands (e.g., grain sliding and crushing, and pore collapse, causing interstitial fluid expulsion under saturated conditions), can significantly affect the constitutive response of the skeleton and the intrinsic permeability. Discrete mechanics (DEM) and the lattice Boltzmann method (LBM) will be used to probe the microstructure---under the current state---to extract the evolution of macroscopic constitutive parameters and the permeability tensor. These evolving macroscopic constitutive parameters are then directly used in continuum scale predictions using the finite element method (FEM) accounting for the coupled solid deformation and fluid diffusion. A particularly valuable aspect of this research is the thorough quantitative verification and validation program at different scales. The multiscale homogenization …
Date:
December 14, 2012
Creator:
Andrade, José E & Rudnicki, John W
Object Type:
Report
System:
The UNT Digital Library
Discretionary Budget Authority by Subfunction: An Overview
President Obama's FY2013 budget submission was released on February 13, 2012. This report provides a graphical overview of historical trends in discretionary budget authority (BA) from FY1976 through FY2011, enacted levels for FY2012 spending, and the levels consistent with the President's proposals for FY2013 through FY2017. Spending caps and budget enforcement mechanisms established in the Budget Control Act (BCA) of 2011 will probably strongly affect the FY2013 budget cycle. This report may provide a starting point for discussions about spending trends and federal priorities, but it does not attempt to explain spending patterns in each policy area.
Date:
February 14, 2012
Creator:
Austin, D. Andrew
Object Type:
Report
System:
The UNT Digital Library
Multi-Physics Analysis of the Fermilab Booster RF Cavity
After about 40 years of operation the RF accelerating cavities in Fermilab Booster need an upgrade to improve their reliability and to increase the repetition rate in order to support a future experimental program. An increase in the repetition rate from 7 to 15 Hz entails increasing the power dissipation in the RF cavities, their ferrite loaded tuners, and HOM dampers. The increased duty factor requires careful modelling for the RF heating effects in the cavity. A multi-physic analysis investigating both the RF and thermal properties of Booster cavity under various operating conditions is presented in this paper.
Date:
May 14, 2012
Creator:
Awida, M.; Reid, J.; Yakovlev, V.; Lebedev, V.; Khabiboulline, T. & Champion, M.
Object Type:
Article
System:
The UNT Digital Library
Doctoral Recital: 2012-06-14 - Laurissa Backlin, soprano
Recital presented at the UNT College of Music Voertman Hall in partial fulfillment of the Doctor of Musical Arts (DMA) degree.
Date:
June 14, 2012
Creator:
Backlin, Laurissa
Object Type:
Sound
System:
The UNT Digital Library
DEVELOPMENT OF NEW MID-INFRARED ULTRAFAST LASER SOURCES FOR COMPACT COHERENT X-RAY SOURCES
In this project, we proposed to develop laser based mid-infrared lasers as a potentially robust and reliable source of ultrafast pulses in the mid-infrared region of the spectrum, and to apply this light source to generating bright, coherent, femtosecond-to-attosecond x-ray beams.
Date:
May 14, 2012
Creator:
Backus, Sterling
Object Type:
Report
System:
The UNT Digital Library
Design Considerations for an MEBT Chopper Absorber of 2.1 MeV H- at the Project X Injector Experiment at Fermilab
The Project X Injector Experiment (PIXIE) will be a prototype of the Project X front end that will be used to validate the design concept and decrease technical risks. One of the most challenging components of PIXIE is the wide-band chopping system of the Medium Energy Beam Transport (MEBT) section, which will form an arbitrary bunch pattern from the initially CW 162.5 MHz 5mA beam. The present scenario assumes diverting 80% of the beam to an absorber to provide a beam with the average current of 1mA to SRF linac. This absorber must withstand a high level of energy deposition and high ion fluence, while being positioned in proximity of the superconductive cavities. This paper discusses design considerations for the absorber. Thermal and mechanical analyses of a conceptual design are presented, and future plans for the fabrication and testing of a prototype are described.
Date:
May 14, 2012
Creator:
Baffes, C.; Awida, M.; Chen, A.; Eidelman, Y.; Lebedev, V.; Prost, L. et al.
Object Type:
Article
System:
The UNT Digital Library
Composite Octet Searches with Jet Substructure
Many new physics models with strongly interacting sectors predict a mass hierarchy between the lightest vector meson and the lightest pseudoscalar mesons. We examine the power of jet substructure tools to extend the 7 TeV LHC sensitivity to these new states for the case of QCD octet mesons, considering both two gluon and two b-jet decay modes for the pseudoscalar mesons. We develop both a simple dijet search using only the jet mass and a more sophisticated jet substructure analysis, both of which can discover the composite octets in a dijet-like signature. The reach depends on the mass hierarchy between the vector and pseudoscalar mesons. We find that for the pseudoscalar-to-vector meson mass ratio below approximately 0.2 the simple jet mass analysis provides the best discovery limit; for a ratio between 0.2 and the QCD-like value of 0.3, the sophisticated jet substructure analysis has the best discovery potential; for a ratio above approximately 0.3, the standard four-jet analysis is more suitable.
Date:
February 14, 2012
Creator:
Bai, Yang & Shelton, Jessie
Object Type:
Article
System:
The UNT Digital Library
Proliferation Resistance and Physical Protection Working Group: Methodology and Applications
We summarize the technical progress and accomplishments on the evaluation methodology for proliferation resistance and physical protection (PR and PP) of Generation IV nuclear energy systems. We intend the results of the evaluations performed with the methodology for three types of users: system designers, program policy makers, and external stakeholders. The PR and PP Working Group developed the methodology through a series of demonstration and case studies. Over the past few years various national and international groups have applied the methodology to nuclear energy system designs as well as to developing approaches to advanced safeguards.
Date:
November 14, 2012
Creator:
Bari, Robert A.; Whitlock, Jeremy; Therios, Ike U. & Peterson, Per F.
Object Type:
Article
System:
The UNT Digital Library
Comprehensive Environmental Response, Compensation, and Liability Act: A Summary of Superfund Cleanup Authorities and Related Provisions of the Act
This report discusses the background and current status of CERCLA (the Comprehensive Environmental Response, Compensation, and Liability Act of 1980), which was a response to a growing desire for the federal government to ensure the cleanup of the nation's most contaminated sites to protect the public from potential harm. Concerns for Congress include funding for this act; most funding comes from potentially responsible parties (PRPs), but some also comes from the CERCLA established Hazardous Substance Superfund Trust Fund.
Date:
June 14, 2012
Creator:
Bearden, David M.
Object Type:
Report
System:
The UNT Digital Library
NATO's Chicago Summit
NATO's 2012 summit of alliance heads of state and government is scheduled to take place in Chicago on May 20-21. U.S. and NATO officials have outlined what they expect to be the Summit's three main agenda items: Defining the next phase of formal transition in Afghanistan and shaping a longer term NATO commitment to the country after the planned end of combat operations by the end of 2014; Securing commitments to maintain and develop the military capabilities necessary to meet NATO's defense and security goals, including through a new "Smart Defense" initiative; and Enhancing NATO's partnerships with non-NATO member states.
Date:
May 14, 2012
Creator:
Belkin, Paul
Object Type:
Report
System:
The UNT Digital Library