74 Matching Results

Results open in a new window/tab.

The Greensheet (Houston, Tex.), Vol. 42, No. 332, Ed. 1 Thursday, August 11, 2011 (open access)

The Greensheet (Houston, Tex.), Vol. 42, No. 332, Ed. 1 Thursday, August 11, 2011

Free weekly newspaper that includes business and classified advertising.
Date: August 11, 2011
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Port Aransas South Jetty (Port Aransas, Tex.), Vol. 42, No. 32, Ed. 1 Thursday, August 11, 2011 (open access)

Port Aransas South Jetty (Port Aransas, Tex.), Vol. 42, No. 32, Ed. 1 Thursday, August 11, 2011

Weekly newspaper from Port Aransas, Texas on Mustang Island that includes local, state and national news along with extensive advertising.
Date: August 11, 2011
Creator: Judson, Mary Henkel
Object Type: Newspaper
System: The Portal to Texas History
The Greensheet (Houston, Tex.), Vol. 42, No. 333, Ed. 1 Thursday, August 11, 2011 (open access)

The Greensheet (Houston, Tex.), Vol. 42, No. 333, Ed. 1 Thursday, August 11, 2011

Free weekly newspaper that includes business and classified advertising.
Date: August 11, 2011
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Trade Adjustment Assistance (TAA) and Its Role in U.S. Trade Policy (open access)

Trade Adjustment Assistance (TAA) and Its Role in U.S. Trade Policy

This report looks at the background of Trade Adjustment Assistance (TAA) in the Trade Expansion Act of 1962, which was created by Congress. It then discusses how the 112th Congress is considering legislative action to extend the TAA - including two issues: how necessary or appropriate the extension is, and whether or not three proposed bills should be voted upon separately.
Date: August 11, 2011
Creator: Hornbeck, J. F. & Rover, Laine Elise
Object Type: Report
System: The UNT Digital Library
Nuclear Cooperation with Other Countries: A Primer (open access)

Nuclear Cooperation with Other Countries: A Primer

This report discusses section 123 of the Atomic Energy Act (AEA), the specific requirements of which must be met in order for the United States to engage in civilian nuclear cooperation with other states. The AEA also provides for exemptions to these requirements, export control licensing procedures, and criteria for terminating cooperation.
Date: August 11, 2011
Creator: Kerr, Paul K. & Nikitin, Mary Beth
Object Type: Report
System: The UNT Digital Library
Texas Jewish Post (Fort Worth, Tex.), Vol. 65, No. 33, Ed. 1 Thursday, August 11, 2011 (open access)

Texas Jewish Post (Fort Worth, Tex.), Vol. 65, No. 33, Ed. 1 Thursday, August 11, 2011

Weekly Jewish newspaper from Fort Worth, Texas that includes local, state and national news along with extensive advertising.
Date: August 11, 2011
Creator: Wisch-Ray, Sharon
Object Type: Newspaper
System: The Portal to Texas History
TARGET: A multi-channel digitizer chip for very-high-energy gamma-ray telescopes (open access)

TARGET: A multi-channel digitizer chip for very-high-energy gamma-ray telescopes

The next-generation very-high-energy (VHE) gamma-ray observatory, the Cherenkov Telescope Array, will feature dozens of imaging atmospheric Cherenkov telescopes (IACTs), each with thousands of pixels of photosensors. To be affordable and reliable, reading out such a mega-channel array requires event recording technology that is highly integrated and modular, with a low cost per channel. We present the design and performance of a chip targeted to this application: the TeV Array Readout with GSa/s sampling and Event Trigger (TARGET). This application-specific integrated circuit (ASIC) has 16 parallel input channels, a 4096-sample buffer for each channel, adjustable input termination, self-trigger functionality, and tight window-selected readout. We report the performance of TARGET in terms of sampling frequency, power consumption, dynamic range, current-mode gain, analog bandwidth, and cross talk. The large number of channels per chip allows a low cost per channel ($10 to $20 including front-end and back-end electronics but not including photosensors) to be achieved with a TARGET-based IACT readout system. In addition to basic performance parameters of the TARGET chip itself, we present a camera module prototype as well as a second-generation chip (TARGET 2), both of which have been produced.
Date: August 11, 2011
Creator: Bechtol, K.; Funk, S.; Okumura, A.; Ruckman, L.; Simons, A.; Tajima, H. et al.
Object Type: Article
System: The UNT Digital Library
A Heteroepitaxial Perovskite Metal-Base Transistor (open access)

A Heteroepitaxial Perovskite Metal-Base Transistor

'More than Moore' captures a concept for overcoming limitations in silicon electronics by incorporating new functionalities in the constituent materials. Perovskite oxides are candidates because of their vast array of physical properties in a common structure. They also enable new electronic devices based on strongly-correlated electrons. The field effect transistor and its derivatives have been the principal oxide devices investigated thus far, but another option is available in a different geometry: if the current is perpendicular to the interface, the strong internal electric fields generated at back-to-back heterojunctions can be used for oxide electronics, analogous to bipolar transistors. Here we demonstrate a perovskite heteroepitaxial metal-base transistor operating at room temperature, enabled by interface dipole engineering. Analysis of many devices quantifies the evolution from hot-electron to permeable-base behaviour. This device provides a platform for incorporating the exotic ground states of perovskite oxides, as well as novel electronic phases at their interfaces.
Date: August 11, 2011
Creator: Yajima, T.; Hikita, Y. & Hwang, H. Y.
Object Type: Article
System: The UNT Digital Library
Reco level Smin and subsystem Smin: improved global inclusive variables for measuring the new physics mass scale in MET events at hadron colliders (open access)

Reco level Smin and subsystem Smin: improved global inclusive variables for measuring the new physics mass scale in MET events at hadron colliders

The variable {radical}s{sub min} was originally proposed in [1] as a model-independent, global and fully inclusive measure of the new physics mass scale in missing energy events at hadron colliders. In the original incarnation of {radical}s{sub min}, however, the connection to the new physics mass scale was blurred by the effects of the underlying event, most notably initial state radiation and multiple parton interactions. In this paper we advertize two improved variants of the {radical}s{sub min} variable, which overcome this problem. First we show that by evaluating the {radical}s{sub min} variable at the RECO level, in terms of the reconstructed objects in the event, the effects from the underlying event are significantly diminished and the nice correlation between the peak in the {radical}s{sub min}{sup (reco)} distribution and the new physics mass scale is restored. Secondly, the underlying event problem can be avoided altogether when the {radical}s{sub min} concept is applied to a subsystem of the event which does not involve any QCD jets. We supply an analytic formula for the resulting subsystem {radical}s{sub min}{sup (sub)} variable and show that its peak exhibits the usual correlation with the mass scale of the particles produced in the subsystem. Finally, we contrast {radical}s{sub …
Date: August 11, 2011
Creator: Konar, Partha; Kong, Kyoungchul; Matchev, Konstantin T. & Park, Myeonghun
Object Type: Article
System: The UNT Digital Library
Discovering New Light States at Neutrino Experiments (open access)

Discovering New Light States at Neutrino Experiments

Experiments designed to measure neutrino oscillations also provide major opportunities for discovering very weakly coupled states. In order to produce neutrinos, experiments such as LSND collide thousands of Coulombs of protons into fixed targets, while MINOS and MiniBooNE also focus and then dump beams of muons. The neutrino detectors beyond these beam dumps are therefore an excellent arena in which to look for long-lived pseudoscalars or for vector bosons that kinetically mix with the photon. We show that these experiments have significant sensitivity beyond previous beam dumps, and are able to partially close the gap between laboratory experiments and supernovae constraints on pseudoscalars. Future upgrades to the NuMI beamline and Project X will lead to even greater opportunities for discovery. We also discuss thin target experiments with muon beams, such as those available in COMPASS, and show that they constitute a powerful probe for leptophilic PNGBs.
Date: August 11, 2011
Creator: Essig, Rouven; Harnik, Roni; Kaplan, Jared & Toro, Natalia
Object Type: Article
System: The UNT Digital Library
Energy Gaps in the Failed High-Tc Superconductor La1.875Ba0.125CuO4 (open access)

Energy Gaps in the Failed High-Tc Superconductor La1.875Ba0.125CuO4

A central issue in high-T{sub c} superconductivity is the nature of the normal-state gap (pseudogap) in the underdoped regime and its relationship with superconductivity. Despite persistent efforts, theoretical ideas for the pseudogap evolve around fluctuating superconductivity, competing order, and spectral weight suppression due to many-body effects. Recently, although some experiments in the superconducting state indicate a distinction between the superconducting gap and pseudogap, others in the normal state, either by extrapolation from high-temperature data or directly from La{sub 1.875)Ba{sub 0.125}CuO{sub 4} (LBCO-1/8) at low temperature, suggest the ground-state pseudogap is a single gap of d-wave form. Here, we report angle-resolved photoemission data from LBCO-1/8, collected with improved experimental conditions, that reveal the ground-state pseudogap has a pronounced deviation from the simple d-wave form. It contains two distinct components: a d-waev component within an extended region around the node and the other abruptly enhanced close to the antinode, pointing to a dual nature of the pseudogap in this failed high-T{sub c} superconductor that involves a possible precursor-pairing energy scale around the node and another of different but unknown origin near the antinode.
Date: August 11, 2011
Creator: unknown
Object Type: Article
System: The UNT Digital Library
Reentrant Insulating State in Ultrathin Manganite Films (open access)

Reentrant Insulating State in Ultrathin Manganite Films

The transport and magnetic properties of La{sub 0.7}Sr{sub 0.3}MnO{sub 3} thin-films grown by pulsed laser deposition on (LaAlO{sub 3}){sub 0.3}(SrAl{sub 0.5}Ta{sub 0.5}O{sub 3}){sub 0.7} single crystal substrates have been investigated. A systematic series with various thicknesses of La{sub 0.7}Sr{sub 0.3}MnO{sub 3} was used to establish a phase diagram - which showed a clear difference compared to films grown on SrTiO{sub 3} substrates, highlighting the importance of film thickness and substrate strain. At 8 unit cells, the boundary between the metallic and insulating ground states, a second abrupt metal-insulator transition was observed at low temperatures, which could be tuned with by magnetic field, and is interpreted as a signature of electronic phase separation.
Date: August 11, 2011
Creator: Bell, Christopher
Object Type: Article
System: The UNT Digital Library
Indirect Dark Matter Detection Limits from the Ultra-Faint Milky Way Satellite Segue 1 (open access)

Indirect Dark Matter Detection Limits from the Ultra-Faint Milky Way Satellite Segue 1

We use new kinematic data from the ultra-faint Milky Way satellite Segue 1 to model its dark matter distribution and derive upper limits on the dark matter annihilation cross-section. Using gamma-ray ux upper limits from the Fermi satellite and MAGIC, we determine cross-section exclusion regions for dark matter annihilation into a variety of different particles including charged leptons. We show that these exclusion regions are beginning to probe the regions of interest for a dark matter interpretation of the electron and positron uxes from PAMELA, Fermi, and HESS, and that future observations of Segue 1 have strong prospects for testing such an interpretation. We additionally discuss prospects for detecting annihilation with neutrinos using the IceCube detector, finding that in an optimistic scenario a few neutrino events may be detected. Finally we use the kinematic data to model the Segue 1 dark matter velocity dispersion and constrain Sommerfeld enhanced models.
Date: August 11, 2011
Creator: Essig, Rouven; Sehgal, Neelima; Strigari, Louis E.; Geha, Marla & Simon, Joshua D.
Object Type: Article
System: The UNT Digital Library
Nanometer-Scale Epitaxial Strain Release in Perovskite Heterostructures Using 'SrAlOx' Sliding Buffer Layers (open access)

Nanometer-Scale Epitaxial Strain Release in Perovskite Heterostructures Using 'SrAlOx' Sliding Buffer Layers

We demonstrate the strain release of LaAlO{sub 3} epitaxial film on SrTiO{sub 3} (001) by inserting ultra-thin 'SrAlO{sub x}' buffer layers. Although SrAlO{sub x} is not a perovskite, nor stable as a single phase in bulk, epitaxy stabilizes the perovskite structure up to a thickness of 2 unit cells (uc). At a critical thickness of 3 uc of SrAlO{sub x}, the interlayer acts as a sliding buffer layer, and abruptly relieves the lattice mismatch between the LaAlO{sub 3} filmand the SrTiO{sub 3} substrate, while maintaining crystallinity. This technique may provide a general approach for strain relaxation of perovskite film far below the thermodynamic critical thickness. A central issue in heteroepitaxial filmgrowth is the inevitable difference in lattice constants between the filmand substrate. Due to this lattice mismatch, thin film are subjected to microstructural strain, which can have a significan effect on the filmproperties. This challenge is especially prominent in the rapidly developing fiel of oxide electronics, where much interest is focused on incorporating the emergent physical properties of oxides in devices. Although strain can be used to great effect to engineer unusual ground states, it is often deleterious for bulk first-orde phase transitions, which are suppressed by the strain and …
Date: August 11, 2011
Creator: Bell, Christopher
Object Type: Article
System: The UNT Digital Library
Cosmic Ray Anomalies from the MSSM? (open access)

Cosmic Ray Anomalies from the MSSM?

The recent positron excess in cosmic rays (CR) observed by the PAMELA satellite may be a signal for dark matter (DM) annihilation. When these measurements are combined with those from FERMI on the total (e{sup +} + e{sup -}) ux and from PAMELA itself on the {anti p}p ratio, these and other results are difficult to reconcile with traditional models of DM, including the conventional minimal Supergravity (mSUGRA) version of Supersymmetry even if boosts as large as 10{sup 3-4} are allowed. In this paper, we combine the results of a previously obtained scan over a more general 19-parameter subspace of the Minimal Supersymmetric Standard Model (MSSM) with a corresponding scan over astrophysical parameters that describe the propagation of CR. We then ascertain whether or not a good fit to this CR data can be obtained with relatively small boost factors while simultaneously satisfying the additional constraints arising from gamma ray data. We find that a specific subclass of MSSM models where the Lightest Supersymmetric Particle (LSP) is mostly pure bino and annihilates almost exclusively into {tau} pairs comes very close to satisfying these requirements. The lightest in this set of models is found to be relatively close in mass to …
Date: August 11, 2011
Creator: Cotta, R. C.; Conley, J. A.; Gainer, J. S.; Hewett, J. L. & Rizzo, T. G.
Object Type: Article
System: The UNT Digital Library
LaVo4: Eu Phosphor Films with Enhanced Eu Solubility (open access)

LaVo4: Eu Phosphor Films with Enhanced Eu Solubility

Eu doped rare-earth orthovanadates are known to be good red phosphor materials. In particular, LaVO{sub 4}:Eu is a promising candidate due to the low Eu-site point symmetry, and thus high dipole transition probability within Judd-Ofelt theory. However, the low solubility limit (< 3 mol %) of Eu in LaVO{sub 4} prevents its efficient use as a phosphor. We present optical evidence of enhanced Eu solubility as high as 10 mol % in LaVO{sub 4}:Eu thin films grown by pulsed laser deposition and postannealing. The photoluminescent intensity exceeded that of YVO{sub 4}:Eu thin films when excited below the host bandgap, indicating stronger direct emission of Eu in LaVO{sub 4}.
Date: August 11, 2011
Creator: Hwang, Harold
Object Type: Article
System: The UNT Digital Library
Discovery of a GeV Blazar Shining Through the Galactic Plane (open access)

Discovery of a GeV Blazar Shining Through the Galactic Plane

The Fermi Large Area Telescope (LAT) discovered a new gamma-ray source near the Galactic plane, Fermi J0109+6134, when it flared brightly in 2010 February. The low Galactic latitude (b = -1.2{sup o}) indicated that the source could be located within the Galaxy, which motivated rapid multi-wavelength follow-up including radio, optical, and X-ray observations. We report the results of analyzing all 19 months of LAT data for the source, and of X-ray observations with both Swift and the Chandra X-ray Observatory. We determined the source redshift, z = 0.783, using a Keck LRIS observation. Finally, we compiled a broadband spectral energy distribution (SED) from both historical and new observations contemporaneous with the 2010 February flare. The redshift, SED, optical line width, X-ray obsorption, and multi-band variability indicate that this new Gev source is a blazar seen through the Galactic plane. Because several of the optical emission lines have equivalent width > 5 {angstrom}, this blazar belongs in the flat-spectrum radio quasar category.
Date: August 11, 2011
Creator: Vandenbroucke, J.; Buehler, R.; Ajello, M.; Bechtol, K.; Bellini, A.; Bolte, M. et al.
Object Type: Article
System: The UNT Digital Library
The Greensheet (Fort Worth, Tex.), Vol. 35, No. 131, Ed. 1 Thursday, August 11, 2011 (open access)

The Greensheet (Fort Worth, Tex.), Vol. 35, No. 131, Ed. 1 Thursday, August 11, 2011

Free weekly newspaper that includes business and classified advertising.
Date: August 11, 2011
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Greensheet (Houston, Tex.), Vol. 42, No. 329, Ed. 1 Thursday, August 11, 2011 (open access)

The Greensheet (Houston, Tex.), Vol. 42, No. 329, Ed. 1 Thursday, August 11, 2011

Free weekly newspaper that includes business and classified advertising.
Date: August 11, 2011
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Greensheet (Arlington-Grand Prairie, Tex.), Vol. 35, No. 129, Ed. 1 Thursday, August 11, 2011 (open access)

The Greensheet (Arlington-Grand Prairie, Tex.), Vol. 35, No. 129, Ed. 1 Thursday, August 11, 2011

Free weekly newspaper that includes business and classified advertising.
Date: August 11, 2011
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Greensheet (Fort Worth, Tex.), Vol. 35, No. 130, Ed. 1 Thursday, August 11, 2011 (open access)

The Greensheet (Fort Worth, Tex.), Vol. 35, No. 130, Ed. 1 Thursday, August 11, 2011

Free weekly newspaper that includes business and classified advertising.
Date: August 11, 2011
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Next-Generation Building Energy Management Systems and Implications for Electricity Markets. (open access)

Next-Generation Building Energy Management Systems and Implications for Electricity Markets.

The U.S. national electric grid is facing significant changes due to aggressive federal and state targets to decrease emissions while improving grid efficiency and reliability. Additional challenges include supply/demand imbalances, transmission constraints, and aging infrastructure. A significant number of technologies are emerging under this environment including renewable generation, distributed storage, and energy management systems. In this paper, we claim that predictive energy management systems can play a significant role in achieving federal and state targets. These systems can merge sensor data and predictive statistical models, thereby allowing for a more proactive modulation of building energy usage as external weather and market signals change. A key observation is that these predictive capabilities, coupled with the fast responsiveness of air handling units and storage devices, can enable participation in several markets such as the day-ahead and real-time pricing markets, demand and reserves markets, and ancillary services markets. Participation in these markets has implications for both market prices and reliability and can help balance the integration of intermittent renewable resources. In addition, these emerging predictive energy management systems are inexpensive and easy to deploy, allowing for broad building participation in utility centric programs.
Date: August 11, 2011
Creator: Zavala, V. M.; Thomas, C.; Zimmerman, M. & Ott, A.
Object Type: Report
System: The UNT Digital Library
Status of Monte-Carlo Event Generators (open access)

Status of Monte-Carlo Event Generators

Recent progress on general-purpose Monte-Carlo event generators is reviewed with emphasis on the simulation of hard QCD processes and subsequent parton cascades. Describing full final states of high-energy particle collisions in contemporary experiments is an intricate task. Hundreds of particles are typically produced, and the reactions involve both large and small momentum transfer. The high-dimensional phase space makes an exact solution of the problem impossible. Instead, one typically resorts to regarding events as factorized into different steps, ordered descending in the mass scales or invariant momentum transfers which are involved. In this picture, a hard interaction, described through fixed-order perturbation theory, is followed by multiple Bremsstrahlung emissions off initial- and final-state and, finally, by the hadronization process, which binds QCD partons into color-neutral hadrons. Each of these steps can be treated independently, which is the basic concept inherent to general-purpose event generators. Their development is nowadays often focused on an improved description of radiative corrections to hard processes through perturbative QCD. In this context, the concept of jets is introduced, which allows to relate sprays of hadronic particles in detectors to the partons in perturbation theory. In this talk, we briefly review recent progress on perturbative QCD in event generation. …
Date: August 11, 2011
Creator: Hoeche, Stefan
Object Type: Article
System: The UNT Digital Library
RISK COMMUNICATION FOR ES&H PROFESSIONALS AND LINE SUPERVISORS PARTICIPANT MANUAL COURSE NUMBER 004111 REV 0.1 JULY 2011 (open access)

RISK COMMUNICATION FOR ES&H PROFESSIONALS AND LINE SUPERVISORS PARTICIPANT MANUAL COURSE NUMBER 004111 REV 0.1 JULY 2011

This course will help you successfully apply risk communication principles when interacting with workers regarding work hazards. What Is the Difference Between a Risk and a Hazard? In many cases, the terms 'risk' and 'hazard' are incorrectly used interchangeably. A hazard is a physical condition or practice with the potential for causing harm/adverse effects. A risk is the probability of harm/adverse effects occurring from an exposure to a hazard. It is modified by the severity of harm (the consequence). Once a hazard is identified, a risk assessment is conducted to determine the severity of the risk. It uses scientific methods and rigorous tests to determine the effects of the risk on people and the environment. Risk Management takes data from the risk assessment and writes policies to help protect people and the environment against the risk. Risk communication is an ongoing process that starts soon after a hazard is identified and continues through the writing of policies. In the past, governing agencies did not do a good job of communicating risk; they would only communicate about risk after studies had been conducted and policies written.
Date: August 11, 2011
Creator: PK, ALDRIDGE & S, ROCKS
Object Type: Article
System: The UNT Digital Library