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World Sheet Commuting beta-gamma CFT and Non-Relativistic StringTheories

Description: We construct a sigma model in two dimensions with Galilean symmetry in flat target space similar to the sigma model of the critical string theory with Lorentz symmetry in 10 flat spacetime dimensions. This is motivated by the works of Gomis and Ooguri[1] and Danielsson et. al.[2, 3]. Our theory is much simpler than their theory and does not assume a compact coordinate. This non-relativistic string theory has a bosonic matter {beta}{gamma} CFT with the conformal weight of {beta} as 1. It is natu… more
Date: August 30, 2007
Creator: Kim, Bom Soo
Partner: UNT Libraries Government Documents Department
open access

Overview of the National Ignition Facility

Description: The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory will be the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. NIF is a 192 beam Nd-glass laser facility that will produce 1.8 MJ, 500 TW of ultraviolet light making it over fifty times more energetic than present ICF facilities. The NIF Project began in 1995 and is scheduled for completion in 2009. Ignition experiments on N… more
Date: August 30, 2007
Creator: Moses, Edward
Partner: UNT Libraries Government Documents Department
open access

TiO2 Nanoparticles as a Soft X-ray Molecular Probe

Description: With the emergence of soft x-ray techniques for imaging cells, there is a pressing need to develop protein localization probes that can be unambiguously identified within the region of x-ray spectrum used for imaging. TiO2 nanocrystal colloids, which have a strong absorption cross-section within the "water-window" region of x-rays, areideally suited as soft x-ray microscopy probes. To demonstrate their efficacy, TiO2-streptavidin nanoconjugates were prepared and subsequently labeled microtubule… more
Date: June 30, 2007
Creator: Larabell, Carolyn; Ashcroft, Jared M.; Gu, Weiwei; Zhang, Tierui; Hughes, Steven M.; Hartman, Keith B. et al.
Partner: UNT Libraries Government Documents Department
open access

SPENT NUCLEAR FUEL STORAGE BASIN WATER CHEMISTRY: ELECTROCHEMICAL EVALUATION OF ALUMINUM CORROSION

Description: The factors affecting the optimal water chemistry of the Savannah River Site spent fuel storage basin must be determines in order to optimize facility efficiency, minimize fuel corrosion, and reduce overall environmental impact from long term spent nuclear fuel storage at the Savannah River Site. The Savannah River National Laboratory is using statistically designed experiments to study the effects of NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, and Cl{sup -} concentrations on alloys commonly used not … more
Date: October 30, 2007
Creator: Hathcock, D
Partner: UNT Libraries Government Documents Department
open access

Sensitivity study of reliable, high-throughput resolution metricsfor photoresists

Description: The resolution of chemically amplified resists is becoming an increasing concern, especially for lithography in the extreme ultraviolet (EUV) regime. Large-scale screening and performance-based down-selection is currently underway to identify resist platforms that can support shrinking feature sizes. Resist screening efforts, however, are hampered by the absence of reliable resolution metrics that can objectively quantify resist resolution in a high-throughput fashion. Here we examine two high-… more
Date: July 30, 2007
Creator: Anderson, Christopher N. & Naulleau, Patrick P.
Partner: UNT Libraries Government Documents Department
open access

Patterns and Implications of Gene Gain and Loss in the Evolution of Prochlorococcus

Description: Prochlorococcus is a marine cyanobacterium that numerically dominates the mid-latitude oceans and is the smallest known oxygenic phototroph. Numerous isolatesfrom diverse areas of the world's oceans have been studied and shown to be physiologically and genetically distinct. All isolates described thus far can be assigned to either a tightly clustered high-light (HL)-adapted clade, or a more divergent low-light (LL)-adapted group. The 16S rRNA sequences of the entire Prochlorococcus group differ… more
Date: July 30, 2007
Creator: Lapidus, Alla; Kettler, Gregory C.; Martiny, Adam C.; Huang, Katherine; Zucker, Jeremy; Coleman, Maureen L. et al.
Partner: UNT Libraries Government Documents Department
open access

Solutions for Summer Electric Power Shortages: Demand Response andits Applications in Air Conditioning and Refrigerating Systems

Description: Demand response (DR) is an effective tool which resolves inconsistencies between electric power supply and demand. It further provides a reliable and credible resource that ensures stable and economical operation of the power grid. This paper introduces systematic definitions for DR and demand side management, along with operational differences between these two methods. A classification is provided for DR programs, and various DR strategies are provided for application in air conditioning and … more
Date: November 30, 2007
Creator: Han, Junqiao & Piette, Mary Ann
Partner: UNT Libraries Government Documents Department
open access

TASI Lectures on the cosmological constant

Description: The energy density of the vacuum, Lambda, is at least 60 orders of magnitude smaller than several known contributions to it. Approaches to this problem are tightly constrained by data ranging from elementary observations to precision experiments. Absent overwhelming evidence to the contrary, dark energy can only be interpreted as vacuum energy, so the venerable assumption that Lambda=0 conflicts with observation. The possibility remains that Lambda is fundamentally variable, though constant ove… more
Date: August 30, 2007
Creator: Bousso, Raphael & Bousso, Raphael
Partner: UNT Libraries Government Documents Department
open access

A cell nanoinjector based on carbon nanotubes

Description: Technologies for introducing molecules into living cells are vital for probing the physical properties and biochemical interactions that govern the cell's behavior. Here we report the development of a nanoscale cell injection system-termed the nanoinjector-that uses carbon nanotubes to deliver cargo into cells. A single multi-walled carbon nanotube attached to an atomic force microscope tip was functionalized with cargo via a disulfide-based linker. Penetration of cell membranes with this 'nano… more
Date: January 30, 2007
Creator: Chen, Xing; Kis, Andras; Zettl, Alex & Bertozzi, Carolyn R.
Partner: UNT Libraries Government Documents Department
open access

STOUT SMEARING FOR TWISTED FERMIONS.

Description: The effect of Stout smearing is investigated in numerical simulations with twisted mass Wilson quarks. The phase transition near zero quark mass is studied on 12{sup 3} x 24, 16{sup 3} x 32 and 24{sup 3} x 48 lattices at lattice spacings a {approx_equal} 0.1-0.125 fm. The phase structure of Wilson fermions with twisted mass ({mu}) has been investigated in [1,2]. As it is explained there, the observed first order phase transition limits the minimal pion mass which can be reached in simulations a… more
Date: July 30, 2007
Creator: SCHOLZ,W.; JANSEN, K.; McNEILE, C.; MONTVAY, I.; RICHARDS, C.; URBACH, C. et al.
Partner: UNT Libraries Government Documents Department
open access

Mechanical and Electrical Properties of CdTe Tetrapods Studied byAtomic Force Microscopy

Description: The mechanical and electrical properties of CdTe tetrapod-shaped nanocrystals have been studied with atomic force microscopy. Tapping mode images of tetrapods deposited on silicon wafers revealed that they contact the surface with the ends of three arms. The length of these arms was found to be 130 {+-} 10 nm. A large fraction of the tetrapods had a shortened vertical arm as a result of fracture during sample preparation. Fracture also occurs when the applied load is a few nanonewtons. Compress… more
Date: August 30, 2007
Creator: Fang, Liang; Park, Jeong Young; Cui, Yi; Alivisatos, Paul; Shcrier, Joshua; Lee, Byounghak et al.
Partner: UNT Libraries Government Documents Department
open access

Radio AGN in 13,240 galaxy clusters from the Sloan Digital Sky Survey

Description: We correlate the positions of 13,240 Brightest Cluster Galaxies (BCGs) with 0.1 {le} z {le} 0.3 from the maxBCG catalog with radio sources from the FIRST survey to study the sizes and distributions of radio AGN in galaxy clusters. We find that 19.7% of our BCGs are radio-loud, and this fraction depends on the stellar mass of the BCG, and to a lesser extent on the richness of the parent cluster (in the sense of increasing radio loudness with increasing mass). The intrinsic size of the radio emis… more
Date: May 30, 2007
Creator: Croft, S.; de Vries, W. & Becker, R.
Partner: UNT Libraries Government Documents Department
open access

Spectral Properties of Quarks in the Quark-Gluon Plasma

Description: We analyze the spectral properties of the quark propagator above the critical temperature for the deconfinement phase transition in quenched lattice QCD using clover improved Wilson fermions. The bare quark mass dependence of the quark spectral function is analyzed by varying the hopping parameter {kappa} in Landau gauge. We assume a two-pole structure for the quark spectral function, which is numerically found to work quite well for any value of {kappa}. It is shown that in the chiral limit th… more
Date: July 30, 2007
Creator: Karsch, F. & Kitazawa, M.
Partner: UNT Libraries Government Documents Department
open access

Stress Corrosion Cracking Response of 304 Stainless Steel in ASerated and Dearated Water

Description: Scoping stress corrosion cracking (SCC) tests of 304 stainless steel (SS) were performed in 75 C and 250 C aerated pressurized water (APW) and 250 C deaerated pressurized water (DPW). The 250 C APW environment was used to initiate intergranular stress corrosion cracking (IGSCC) and then the water was deaerated and hydrogenated to see if IGSCC continued in 250 C DPW. Tests were performed with and without 200 ppb SO{sub 4}{sup =}. The 304 SS test materials were evaluated in either the as-received… more
Date: April 30, 2007
Creator: Mills, W. J.
Partner: UNT Libraries Government Documents Department
open access

Changes in vigorous physical activity and incident diabetes inmale runners

Description: We examined the dose-response relationship between changes in reported vigorous exercise (running distance, {Delta}km/wk) and self-reported physician diagnosed diabetes in 25,988 men followed prospectively for (mean {+-} SD) 7.8 {+-} 1.8 years. Logistic regression analyses showed that the log odds for diabetes declined significantly in relation to men's {Delta}km/wk (coefficient {+-} SE: -0.012 {+-} 0.004, P < 0.01), which remained significant when adjusted for BMI (-0.018 {+-} 0.003, P <… more
Date: April 30, 2007
Creator: Williams, Paul T.
Partner: UNT Libraries Government Documents Department
open access

REVERSIBLE CONVERSION BETWEEN CHEMICAL AND ELECTRICAL ENERGIES CATALYZED BY Ru COMPLEXES AIMED TO CONSTRUCT SUSTAINABLE SOCIETY.

Description: The present study demonstrates that [Ru{sup II}(NH{sub 3})(q)(trpy)]{sup +} has an ability to oxidize alcohols catalytically under very mild conditions under electrolysis at +0.35 V in MeOH. The elucidation of the reaction mechanisms in the alcohol-oxidation is underway.
Date: November 30, 2007
Creator: TANAKA,K.; WADA, T.; FUJITA, E. & MUCKERMAN, J.
Partner: UNT Libraries Government Documents Department
open access

Spectroscopic Studies of Structure, Dynamics and Reactivity in Ionic Liquids.

Description: Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs are generally nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other … more
Date: November 30, 2007
Creator: Wishart, J. F.
Partner: UNT Libraries Government Documents Department
open access

Visible Light Absorption of Binuclear TiOCoII Charge-Transfer UnitAssembled in Mesoporous Silica

Description: Grafting of CoII(NCCH3)2Cl2 onto mesoporous Ti-MCM-41 silicain acetonitrile solution affords binuclear Ti-O-CoII sites on the poresurface under complete replacement of the precursor ligands byinteractions with anchored Ti centers and the silica surface. The CoIIligand field spectrum signals that the Co centers are anchored on thepore surface in tetrahedral coordination. FT-infrared action spectroscopyusing ammonia gas adsorption reveals Co-O-Si bond modes at 831 and 762cm-1. No Co oxide cluster… more
Date: January 30, 2007
Creator: Han, Hongxian & Frei, Heinz
Partner: UNT Libraries Government Documents Department
open access

Extensive Set of Low-Fidelity Covariances in Fast Neutron Region.

Description: An extensive set of covariances for neutron cross sections has been developed to provide initial, low-fidelity but consistent uncertainty data for nuclear criticality safety applications. The methodology for the determination of such covariances in fast neutron region is presented. It combines the nuclear reaction code EMPIRE, which calculates sensitivity to nuclear reaction model parameters and the Bayesian code KALMAN to propagate uncertainty of the model parameters onto cross sections. Takin… more
Date: July 30, 2007
Creator: Pigni, M. T.; Herman, M.; Oblozinsky, P. & Rochman, D.
Partner: UNT Libraries Government Documents Department
open access

PHASE STRUCTURE OF TWISTED EGUCHI-KAWAI MODEL.

Description: We study the phase structure of the four-dimensional twisted Eguchi-Kawai model using numerical simulations. This model is an effective tool for studying SU(N) gauge theory in the large-N limit and provides a nonperturbative formulation of the gauge theory on noncommutative spaces. Recently it was found that its Z{sub n}{sup 4} symmetry, which is crucial for the validity of this model, can break spontaneously in the intermediate coupling region. We investigate in detail the symmetry breaking po… more
Date: July 30, 2007
Creator: Ishikawa, T.; Azeyanagi, T.; Hanada, M. & Hirata, T.
Partner: UNT Libraries Government Documents Department
open access

Coupled Model Simulations of Boreal Summer Intraseasonal (30-50 day) Variability, Part 1: Systematic Errors and Caution on Use of Metrics

Description: Boreal summer intraseasonal (30-50 day) variability (BSISV) over the Asian monsoon region is more complex than its boreal winter counterpart, the Madden-Julian oscillation (MJO), since it also exhibits northward and northwestward propagating convective components near India and over the west Pacific. Here we analyze the BSISV in the CMIP3 and two CMIP2+ coupled ocean-atmosphere models. Though most models exhibit eastward propagation of convective anomalies over the Indian Ocean, difficulty rema… more
Date: May 30, 2007
Creator: Sperber, K R & Annamalai, H
Partner: UNT Libraries Government Documents Department
open access

TEMPEST Simulations of Collisionless Damping of Geodesic-Acoustic Mode in Edge Plasma Pedestal

Description: The fully nonlinear (full-f) 4D TEMPEST gyrokinetic continuum code produces frequency, collisionless damping of GAM and zonal flow with fully nonlinear Boltzmann electrons for the inverse aspect ratio {epsilon}-scan and the tokamak safety factor q-scan in homogeneous plasmas. The TEMPEST simulation shows that GAM exists in edge plasma pedestal for steep density and temperature gradients, and an initial GAM relaxes to the standard neoclassical residual, rather than Rosenbluth-Hinton residual due… more
Date: May 30, 2007
Creator: Xu, X. Q.; Xiong, Z.; Nevins, W. M. & McKee, G. R.
Partner: UNT Libraries Government Documents Department
open access

The Ability of the United States Federal Radiological Monitoring and Assessment Center to Collect and Disseminate Environmental Measurements during Radiological Emergencies

Description: The Federal Radiological Monitoring and Assessment Center (FRMAC) is the United States’ response organization for radiological emergencies. The FRMAC is structured as an operations center and employs the combined resources of several federal agencies to respond to any disaster resulting in the release of radioactivity. The mission of the FRMAC is to support state and local authorities in the gathering of environmental data using an array of survey equipment ranging from alpha probes, beta/gamma… more
Date: April 30, 2007
Creator: Essex, Craig Marianno and James
Partner: UNT Libraries Government Documents Department
open access

Predictive wavefront control for Adaptive Optics with arbitrary control loop delays

Description: We present a modification of the closed-loop state space model for AO control which allows delays that are a non-integer multiple of the system frame rate. We derive the new forms of the Predictive Fourier Control Kalman filters for arbitrary delays and show that they are linear combinations of the whole-frame delay terms. This structure of the controller is independent of the delay. System stability margins and residual error variance both transition gracefully between integer-frame delays.
Date: October 30, 2007
Creator: Poyneer, L A & Veran, J
Partner: UNT Libraries Government Documents Department
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