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The Impact of the 2002 Delaware Smoking Ordinance on Heart Attack and Asthma (open access)

The Impact of the 2002 Delaware Smoking Ordinance on Heart Attack and Asthma

This article analyzes the Delaware Hospital Discharge Database, and identified state and non-state residents discharged with AMI or asthma for the years 1999 to 2004. Statistical data analysis compared the incidence of AMI or asthma for each group before (1999–2002) and after (2003–2004) the amendment. As a result, the authors found that pre-ordinance and post-ordinance quarterly rates of AMI for Delaware residents were 451 (se = 21) and 430 (se = 21) respectively, representing a 4.7% reduction.
Date: December 2, 2010
Creator: Moraros, John; Bird, Yelena; Chen, Shande; Buckingham, Robert; Meltzer, Richard S.; Prapasiri, Surasri et al.
System: The UNT Digital Library
Deuterium Retention in NSTX with Lithium Conditioning (open access)

Deuterium Retention in NSTX with Lithium Conditioning

High (≈ 90%) deuterium retention was observed in NSTX gas balance measurements both withand without lithiumization of the carbon plasma facing components. The gas retained in ohmic discharges was measured by comparing the vessel pressure rise after a discharge to that of a gasonly pulse with the pumping valves closed. For neutral beam heated discharges the gas input and gas pumped by the NB cryopanels were tracked. The discharges were followed by outgassing of deuterium that reduced the retention. The relationship between retention and surface chemistry was explored with a new plasma-material interface probe connected to an in-vacuo surface science station that exposed four material samples to the plasma. XPS and TDS analysis showed that the binding of D atoms is fundamentally changed by lithium - in particular atoms are weakly bonded in regions near lithium atoms bound to either oxygen or the carbon matrix.
Date: June 2, 2010
Creator: C.H. Skinner, J.P. Allain, W. Blanchard, H.W. Kugel, R. Maingi, L. Roquemore, V. Soukhanovskii, C.N. Taylor
System: The UNT Digital Library
Dynamically tuned high-Q AC-dipole implementation (open access)

Dynamically tuned high-Q AC-dipole implementation

AC-dipole magnets are typically implemented as a parallel LC resonant circuit. To maximize efficiency, it's beneficial to operate at a high Q. This, however, limits the magnet to a narrow frequency range. Current designs therefore operate at a low Q to provide a wider bandwidth at the cost of efficiency. Dynamically tuning a high Q resonant circuit tries to maintain a high efficiency while providing a wide frequency range. The results of ongoing efforts at BNL to implement dynamically tuned high-Q AC dipoles will be presented.
Date: May 2, 2010
Creator: Oddo, P.; Bai, M.; Dawson, W.C.; Meng, W.; Mernick, K.; Pai, C. et al.
System: The UNT Digital Library
Dependence of Band Renormalization Effect on the Number of Copper-oxide Layers in Tl-based Copper-oxide Superconductor using Angle-resolved Photoemission Spectroscopy (open access)

Dependence of Band Renormalization Effect on the Number of Copper-oxide Layers in Tl-based Copper-oxide Superconductor using Angle-resolved Photoemission Spectroscopy

Here we report the first angle-resolved photoemission measurement on nearly optimally doped multilayer Tl-based superconducting cuprates (Tl-2212 and Tl-1223) and a comparison study to single-layer (Tl-2201) compound. A kink in the band dispersion is found in all three compounds but exhibits different momentum dependence for the single-layer and multilayer compounds, reminiscent to that of Bi-based cuprates. This layer number dependent renormalization effect strongly implies that the spin-resonance mode is unlikely to be responsible for the dramatic renormalization effect near the antinodal region.
Date: June 2, 2010
Creator: Lee, Wei-Sheng
System: The UNT Digital Library
Nodal Quasiparticle in Pseudogapped Colossal Magnetoresistive Manganites (open access)

Nodal Quasiparticle in Pseudogapped Colossal Magnetoresistive Manganites

A characteristic feature of the copper oxide high-temperature superconductors is the dichotomy between the electronic excitations along the nodal (diagonal) and antinodal (parallel to the Cu-O bonds) directions in momentum space, generally assumed to be linked to the d-wave symmetry of the superconducting state. Angle-resolved photoemission measurements in the superconducting state have revealed a quasiparticle spectrum with a d-wave gap structure that exhibits a maximum along the antinodal direction and vanishes along the nodal direction. Subsequent measurements have shown that, at low doping levels, this gap structure persists even in the high-temperature metallic state, although the nodal points of the superconducting state spread out in finite Fermi arcs. This is the so-called pseudogap phase, and it has been assumed that it is closely linked to the superconducting state, either by assigning it to fluctuating superconductivity or by invoking orders which are natural competitors of d-wave superconductors. Here we report experimental evidence that a very similar pseudogap state with a nodal-antinodal dichotomous character exists in a system that is markedly different from a superconductor: the ferromagnetic metallic groundstate of the colossal magnetoresistive bilayer manganite La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7}. Our findings therefore cast doubt on the assumption that the pseudogap state …
Date: June 2, 2010
Creator: Mannella, N.
System: The UNT Digital Library
Open Automated Demand Response Technologies for Dynamic Pricing and Smart Grid (open access)

Open Automated Demand Response Technologies for Dynamic Pricing and Smart Grid

We present an Open Automated Demand Response Communications Specifications (OpenADR) data model capable of communicating real-time prices to electricity customers. We also show how the same data model could be used to for other types of dynamic pricing tariffs (including peak pricing tariffs, which are common throughout the United States). Customers participating in automated demand response programs with building control systems can respond to dynamic prices by using the actual prices as inputs to their control systems. Alternatively, prices can be mapped into"building operation modes," which can act as inputs to control systems. We present several different strategies customers could use to map prices to operation modes. Our results show that OpenADR can be used to communicate dynamic pricing within the Smart Grid and that OpenADR allows for interoperability with existing and future systems, technologies, and electricity markets.
Date: June 2, 2010
Creator: Ghatikar, Girish; Mathieu, Johanna L.; Piette, Mary Ann & Kiliccote, Sila
System: The UNT Digital Library
Size-Controlled Synthesis and Optical Properties of Monodisperse Colloidal Magnesium Oxide Nanocrystals (open access)

Size-Controlled Synthesis and Optical Properties of Monodisperse Colloidal Magnesium Oxide Nanocrystals

colloids ? luminescence ? metal oxides ? nanocrystals ? synthesis design
Date: April 2, 2010
Creator: Milliron, Delia J.; Urban, Jeffrey J. & Moon, Hoi Ri
System: The UNT Digital Library
IN SITU REMEDIATION OF CONTAMINATED SEDIMENTS - ACTIVE CAPPING TECHNOLOGY (open access)

IN SITU REMEDIATION OF CONTAMINATED SEDIMENTS - ACTIVE CAPPING TECHNOLOGY

Active capping is a relatively new approach for treating contaminated sediments. It involves applying chemically reactive amendments to the sediment surface. The main role of active caps is to stabilize contaminants in contaminated sediments, lower the bioavailable pool of contaminants, and reduce the release of contaminants to the water column. Metals are common contaminants in many marine and fresh water environments as a result of industrial and military activities. The mobile, soluble forms of metals are generally considered toxic. Induced chemical precipitation of these metals can shift toxic metals from the aqueous phase to a solid, precipitated phase which is often less bioavailable. This approach can be achieved through application of sequestering agents such as rock phosphates, organoclays, zeolites, clay minerals, and biopolymers (e.g., chitosan) in active capping technology. Active capping holds great potential for a more permanent solution that avoids residual risks resulting from contaminant migration through the cap or breaching of the cap. In addition to identifying superior active capping agents, research is needed to optimize application techniques, application rates, and amendment combinations that maximize sequestration of contaminants. A selected set of active capping treatment technologies has been demonstrated at a few sites, including a field demonstration at …
Date: September 2, 2010
Creator: Knox, A.; Roberts, J.; Paller, M. & Reible, D.
System: The UNT Digital Library
Comments on large-N volume independence (open access)

Comments on large-N volume independence

We study aspects of the large-N volume independence on R{sup 3} X L{sup {Gamma}}, where L{sup {Gamma}} is a {Gamma}site lattice for Yang-Mills theory with adjoint Wilson-fermions. We find the critical number of lattice sites above which the center-symmetry analysis on L{sup {Gamma}} agrees with the one on the continuum S{sup 1}. For Wilson parameter set to one and {Gamma}{>=}2, the two analyses agree. One-loop radiative corrections to Wilson-line masses are finite, reminiscent of the UV-insensitivity of the Higgs mass in deconstruction/Little-Higgs theories. Even for theories with {Gamma}=1, volume independence in QCD(adj) may be guaranteed to work by tuning one low-energy effective field theory parameter. Within the parameter space of the theory, at most three operators of the 3d effective field theory exhibit one-loop UV-sensitivity. This opens the analytical prospect to study 4d non-perturbative physics by using lower dimensional field theories (d=3, in our example).
Date: June 2, 2010
Creator: Poppitz, Erich; U., /Toronto; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept.
System: The UNT Digital Library
IDENTIFICATION OF APPROPRIATE QUALIFICATION TESTING AND END-OF-LIFE WASTE STORAGE CONSIDERATIONS FOR DEEP BED SAND FILTERS (open access)

IDENTIFICATION OF APPROPRIATE QUALIFICATION TESTING AND END-OF-LIFE WASTE STORAGE CONSIDERATIONS FOR DEEP BED SAND FILTERS

Deep bed sand (DBS) filters have filtered radioactive particulates at two United States Department of Energy (DOE) sites since 1948. Some early DBS filters experienced issues with chemical attack on support tiles, requiring significant repairs. Designs of DBS filters constructed since 1970 paid greater attention to chemical compatibility, resulting in decades of reliable performance since 1975.
Date: June 2, 2010
Creator: Matthews, K.
System: The UNT Digital Library
Identification of the Charge Carriers in Cerium Phosphate Ceramics (open access)

Identification of the Charge Carriers in Cerium Phosphate Ceramics

The total conductivity of Sr-doped cerium orthophosphate changes by nearly two orders of magnitude depending on the oxygen and hydrogen content of the atmosphere. The defect model for the system suggests that this is because the identity of the dominant charge carrier can change from electron holes to protons when the sample is in equilibrium with air vs. humidified hydrogen. In this work are presented some preliminary measurements that can help to clarify this exchange between carriers. The conduction behavior of a 2percent Sr-doped CePO4 sample under symmetric atmospheric conditions is investigated using several techniques, including AC impedance, H/D isotope effects, and chronoamperometry.
Date: June 2, 2010
Creator: Ray, Hannah L. & Jonghe, Lutgard C. De
System: The UNT Digital Library
Nanoscale Electronic Inhomogeneity in In_2Se_3 Nanoribbons Revealed by Microwave Impedance Microscopy (open access)

Nanoscale Electronic Inhomogeneity in In_2Se_3 Nanoribbons Revealed by Microwave Impedance Microscopy

Driven by interactions due to the charge, spin, orbital, and lattice degrees of freedom, nanoscale inhomogeneity has emerged as a new theme for materials with novel properties near multiphase boundaries. As vividly demonstrated in complex metal oxides and chalcogenides, these microscopic phases are of great scientific and technological importance for research in hightemperature superconductors, colossal magnetoresistance effect, phase-change memories, and domain switching operations. Direct imaging on dielectric properties of these local phases,however, presents a big challenge for existing scanning probe techniques. Here, we report the observation of electronic inhomogeneity in indium selenide (In{sub 2}Se{sub 3}) nanoribbons by near-field scanning microwave impedance microscopy. Multiple phases with local resistivity spanning six orders of magnitude are identified as the coexistence of superlattice, simple hexagonal lattice and amorphous structures with {approx}100nm inhomogeneous length scale, consistent with high-resolution transmission electron microscope studies. The atomic-force-microscope-compatible microwave probe is able to perform quantitative sub-surface electronic study in a noninvasive manner. Finally, the phase change memory function in In{sub 2}Se{sub 3} nanoribbon devices can be locally recorded with big signal of opposite signs.
Date: June 2, 2010
Creator: Lai, K.J.
System: The UNT Digital Library
Theory of Fano Resonances in Graphene: The Kondo effect probed by STM (open access)

Theory of Fano Resonances in Graphene: The Kondo effect probed by STM

We consider the theory of Kondo effect and Fano factor energy dependence for magnetic impurity (Co) on graphene. We have performed a first principles calculation and find that the two dimensional E{sub 1} representation made of d{sub xz}, d{sub yz} orbitals is likely to be responsible for the hybridization and ultimately Kondo screening for cobalt on graphene. There are few high symmetry sites where magnetic impurity atom can be adsorbed. For the case of Co atom in the middle of hexagon of carbon lattice we find anomalously large Fano q-factor, q {approx} 80 and strongly suppressed coupling to conduction band. This anomaly is a striking example of quantum mechanical interference related to the Berry phase inherent to graphene band structure.
Date: June 2, 2010
Creator: Wehling, T.O.
System: The UNT Digital Library
Beam-energy and laser beam-profile monitor at the BNL LINAC (open access)

Beam-energy and laser beam-profile monitor at the BNL LINAC

We are developing a non-interceptive beam profile and energy monitor for H{sup -} beams in the high energy beam transport (HEBT) line at the Brookhaven National Lab linac. Electrons that are removed from the beam ions either by laser photodetachment or stripping by background gas are deflected into a Faraday cup. The beam profile is measured by stepping a narrow laser beam across the ion beam and measuring the electron charge vs. transverse laser position. There is a grid in front of the collector that can be biased up to 125kV. The beam energy spectrum is determined by measuring the electron charge vs. grid voltage. Beam electrons have the same velocity as the beam and so have an energy of 1/1836 of the beam protons. A 200MeV H{sup -} beam yields 109keV electrons. Energy measurements can be made with either laser-stripped or gas-stripped electrons.
Date: May 2, 2010
Creator: Connolly, R.; Briscoe, B.; Degen, C.; DeSanto, L.; Meng, W.; Minty, M. et al.
System: The UNT Digital Library
Visualization of Charge Distribution in a Lithium Battery Electrode (open access)

Visualization of Charge Distribution in a Lithium Battery Electrode

We describe a method for direct determination and visualization of the distribution of charge in a composite electrode. Using synchrotron X-ray microdiffraction, state-of-charge profiles in-plane and normal to the current collector were measured. In electrodes charged at high rate, the signatures of nonuniform current distribution were evident. The portion of a prismatic cell electrode closest to the current collector tab had the highest state of charge due to electronic resistance in the composite electrode and supporting foil. In a coin cell electrode, the active material at the electrode surface was more fully charged than that close to the current collector because the limiting factor in this case is ion conduction in the electrolyte contained within the porous electrode.
Date: July 2, 2010
Creator: Liu, Jun; Kunz, Martin; Chen, Kai; Tamura, Nobumichi & Richardson, Thomas J.
System: The UNT Digital Library
Probing Reaction Dynamics of Transition-Metal Complexes in Solution via Time-Resolved Soft X-ray Spectroscopy (open access)

Probing Reaction Dynamics of Transition-Metal Complexes in Solution via Time-Resolved Soft X-ray Spectroscopy

We report the first time-resolved soft x-ray measurements of solvated transition-metal complexes. L-edge spectroscopy directly probes dynamic changes in ligand-field splitting of 3d orbitals associated with the spin transition, and mediated by changes in ligand-bonding.
Date: May 2, 2010
Creator: Huse, Nils; Kim, Tae Kyu; Khalil, Munira; Jamula, Lindsey; McCusker, James K. & Schoenlein, Robert W.
System: The UNT Digital Library
Constraints on the flux of Ultra-High Energy neutrinos from WSRT observations (open access)

Constraints on the flux of Ultra-High Energy neutrinos from WSRT observations

Context. Ultra-high energy (UHE) neutrinos and cosmic rays initiate particle cascades underneath theMoon?s surface. These cascades have a negative charge excess and radiate Cherenkov radio emission in a process known as the Askaryan effect. The optimal frequencywindow for observation of these pulses with radio telescopes on the Earth is around 150 MHz. Aims. By observing the Moon with the Westerbork Synthesis Radio Telescope array we are able to set a new limit on the UHEneutrino flux. Methods. The PuMa II backend is used to monitor the Moon in 4 frequency bands between 113 and 175 MHz with a samplingfrequency of 40 MHz. The narrowband radio interference is digitally filtered out and the dispersive effect of the Earth?s ionosphere is compensated for. A trigger system is implemented to search for short pulses. By inserting simulated pulses in the raw data, thedetection efficiency for pulses of various strength is calculated. Results. With 47.6 hours of observation time, we are able to set a limit onthe UHE neutrino flux. This new limit is an order of magnitude lower than existing limits. In the near future, the digital radio array LOFAR will be used to achieve an even lower limit.
Date: April 2, 2010
Creator: Scholten, O.; Bacelar, J.; Braun, R.; de Bruyn, A.G.; Falcke, H.; Singh, K. et al.
System: The UNT Digital Library
Investigating two-photon double ionization of D2 by XUV-Pump -- XUV-Probe experiments at FLASH (open access)

Investigating two-photon double ionization of D2 by XUV-Pump -- XUV-Probe experiments at FLASH

Using a novel split-mirror set-up attached to a Reaction Microscope at the Free electron LASer in Hamburg (FLASH) we demonstrate an XUV-pump -- XUV-probe ((hbar omega = 38 eV) experiment by tracing the ultra-fast nuclear wave-packet motion in the D2+ (1s sigma g-state) with<10 fs time resolution. Comparison with time-dependent calculations yields excellent agreement with the measured vibrational period of 22+-4 fs in D2+, points to the importance of the inter-nuclear distance dependent ionization probability and paves the way to control sequential and non-sequential two-photon double ionization contributions.
Date: August 2, 2010
Creator: Collaboration, FLASH; Jiang, Y.; Rudenko, A.; Perez-Torres, J.; Foucar, L.; Kurka, M. et al.
System: The UNT Digital Library
Annealing a Follow-up Program: Improvement of the Dark Energy Figure of Merit for Optical Galaxy Cluster Surveys (open access)

Annealing a Follow-up Program: Improvement of the Dark Energy Figure of Merit for Optical Galaxy Cluster Surveys

The precision of cosmological parameters derived from galaxy cluster surveys is limited by uncertainty in relating observable signals to cluster mass. We demonstrate that a small mass-calibration follow-up program can significantly reduce this uncertainty and improve parameter constraints, particularly when the follow-up targets are judiciously chosen. To this end, we apply a simulated annealing algorithm to maximize the dark energy information at fixed observational cost, and find that optimal follow-up strategies can reduce the observational cost required to achieve a specified precision by up to an order of magnitude. Considering clusters selected from optical imaging in the Dark Energy Survey, we find that approximately 200 low-redshift X-ray clusters or massive Sunyaev-Zel'dovich clusters can improve the dark energy figure of merit by 50%, provided that the follow-up mass measurements involve no systematic error. In practice, the actual improvement depends on (1) the uncertainty in the systematic error in follow-up mass measurements, which needs to be controlled at the 5% level to avoid severe degradation of the results; and (2) the scatter in the optical richness-mass distribution, which needs to be made as tight as possible to improve the efficacy of follow-up observations.
Date: June 2, 2010
Creator: Wu, Hao-Yi; Rozo, Eduardo & Wechsler, Risa H.
System: The UNT Digital Library
Sensing Current and Forces with SPM (open access)

Sensing Current and Forces with SPM

Atomic force microscopy (AFM) and scanning tunneling microscopy (STM) are well established techniques to image surfaces and to probe material properties at the atomic and molecular scale. In this review, we show hybrid combinations of AFM and STM that bring together the best of two worlds: the simultaneous detection of atomic scale forces and conduction properties. We illustrate with several examples how the detection of forces during STM and the detection of currents during AFM can give valuable additional information of the nanoscale material properties.
Date: July 2, 2010
Creator: Park, Jeong Y.; Maier, Sabine; Hendriksen, Bas & Salmeron, Miquel
System: The UNT Digital Library
Residual-gas-ionization beam profile monitors in RHIC (open access)

Residual-gas-ionization beam profile monitors in RHIC

Four ionization profile monitors (IPMs) are in RHIC to measure vertical and horizontal beam profiles in the two rings. These work by measuring the distribution of electrons produced by beam ionization of residual gas. During the last two years both the collection accuracy and signal/noise ratio have been improved. An electron source is mounted across the beam pipe from the collector to monitor microchannel plate (MCP) aging and the signal electrons are gated to reduce MCP aging and to allow charge replenishment between single-turn measurements. Software changes permit simultaneous measurements of any number of individual bunches in the ring. This has been used to measure emittance growth rates on six bunches of varying intensities in a single store. Also the software supports FFT analysis of turn-by-turn profiles of a single bunch at injection to detect dipole and quadrupole oscillations.
Date: May 2, 2010
Creator: Connolly, R.; Fite, J.; Jao, S. & Trabocchi, C.
System: The UNT Digital Library
X-ray magnetic circular dichroism and reflection anisotropy spectroscopy Kerr effect studies of capped magnetic nanowires (open access)

X-ray magnetic circular dichroism and reflection anisotropy spectroscopy Kerr effect studies of capped magnetic nanowires

Aligned Co wires grown on Pt(997) under ultra-high vacuum conditions have been capped successfully by the epitaxial growth of Au monolayers (ML) at room temperature. The samples were kept under vacuum except when transferring between apparatus or when making some of the measurements. No degradation of the Co wires was detected during the measurements. The magneto-optic response of the system was measured using X-ray magnetic circular dichroism (XMCD) at the Co L{sub 2,3} edge and reflection anisotropy spectroscopy (RAS) at near normal incidence, which is sensitive to the normal component of the out-of-plane magnetization via the Kerr effect (MOKE). Capping the wires significantly impacts their magnetic properties. Comparison of the magneto-optic response of the system at X-ray and optical energies reveals small differences that are attributed to the induced moment in the Pt substrate and Au capping layer not picked up by the element specific XMCD measurements. The sensitivity of RAS-MOKE is sufficient to allow the determination of the easy axis direction of the capped wires to within a few degrees. The results for a 6-atom-wide Co wire sample, capped with 6 ML of Au, are consistent with the capped wires possessing perpendicular magnetization.
Date: March 2, 2010
Creator: Cunniffe, J. P.; McNally, D.E.; Liberati, M.; Arenholz, E.; McGuinness, C. & McGilp, J. F.
System: The UNT Digital Library
Separation of High Order Harmonics with Fluoride Windows (open access)

Separation of High Order Harmonics with Fluoride Windows

The lower orders produced in high order harmonic generation can be effciently temporally separated into monochromatic pulses by propagation in a Fluoride window while still preserving their femtosecond pulse duration. We present calculations for MgF2, CaF2, and LiF windows for the third, fifth, and seventh harmonics of 800 nm. We demonstrate the use of this simple and inexpensive technique in a femtosecond pump/probe experiment using the fifth harmonic.
Date: August 2, 2010
Creator: Allison, Tom; van Tilborg, Jeroen; Wright, Travis; Hertlein, Marcus; Falcone, Roger & Belkacem, Ali
System: The UNT Digital Library
FINITE ELEMENT ANALYSIS OF BULK TRITIUM SHIPPING PACKAGE (open access)

FINITE ELEMENT ANALYSIS OF BULK TRITIUM SHIPPING PACKAGE

The Bulk Tritium Shipping Package was designed by Savannah River National Laboratory. This package will be used to transport tritium. As part of the requirements for certification, the package must be shown to meet the scenarios of the Hypothetical Accident Conditions (HAC) defined in Code of Federal Regulations Title 10 Part 71 (10CFR71). The conditions include a sequential 30-foot drop event, 30-foot dynamic crush event, and a 40-inch puncture event. Finite Element analyses were performed to support and expand upon prototype testing. Cases similar to the tests were evaluated. Additional temperatures and orientations were also examined to determine their impact on the results. The peak stress on the package was shown to be acceptable. In addition, the strain on the outer drum as well as the inner containment boundary was shown to be acceptable. In conjunction with the prototype tests, the package was shown to meet its confinement requirements.
Date: June 2, 2010
Creator: Jordan, J.
System: The UNT Digital Library