States

Month

Topological Strings And (Almost) Modular Forms (open access)

Topological Strings And (Almost) Modular Forms

The B-model topological string theory on a Calabi-Yau threefold X has a symmetry group {Lambda}, generated by monodromies of the periods of X. This acts on the topological string wave function in a natural way, governed by the quantum mechanics of the phase space H{sup 3}(X). We show that, depending on the choice of polarization, the genus g topological string amplitude is either a holomorphic quasi-modular form or an almost holomorphic modular form of weight 0 under {Lambda}. Moreover, at each genus, certain combinations of genus g amplitudes are both modular and holomorphic. We illustrate this for the local Calabi-Yau manifolds giving rise to Seiberg-Witten gauge theories in four dimensions and local IP{sub 2} and IP{sub 1} x IP{sub 1}. As a byproduct, we also obtain a simple way of relating the topological string amplitudes near different points in the moduli space, which we use to give predictions for Gromov-Witten invariants of the orbifold C{sub 3}/ZZ{sub 3}.
Date: May 4, 2007
Creator: Aganagic, Mina; Bouchard, Vincent & Klemm, Albrecht
Object Type: Article
System: The UNT Digital Library
Laser heating of solid matter by light pressure-driven shocks (open access)

Laser heating of solid matter by light pressure-driven shocks

Heating by irradiation of a solid surface in vacuum with 5 x 10{sup 20} W cm{sup -2}, 0.8 ps, 1.05 {micro}m wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo and V. A surface layer is heated to {approx} 5 keV with an axial temperature gradient of 0.6 {micro}m scale length. Images of Ni Ly{sub {alpha}} show the hot region has a {approx} 25 {micro}m diameter, much smaller than {approx} 70 {micro}m region of K{sub {alpha}} emission. 2D particle-in-cell (PIC) simulations suggest that the surface heating is due to a light pressure driven shock.
Date: May 4, 2007
Creator: Akli, K.; Hansen, S. B.; Kemp, A. J.; Freeman, R. R.; Beg, F. N.; Clark, D. et al.
Object Type: Article
System: The UNT Digital Library
The e+e- to to K+ K- \pi+\pi-, K+ K- \pi0\pi0 and K+ K- K+ K- Cross Sections Measured with Initial-State Radiation (open access)

The e+e- to to K+ K- \pi+\pi-, K+ K- \pi0\pi0 and K+ K- K+ K- Cross Sections Measured with Initial-State Radiation

We study the processes e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{gamma}, K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0}{gamma} and K{sup +}K{sup -}K{sup +}K{sup -}{gamma}, where the photon is radiated from the initial state. About 34600, 4400 and 2300 fully reconstructed events respectively, are selected from 232 fb{sup -1} of BABAR data. The invariant mass of the hadronic final state defines the effective e{sup +}e{sup -} center-of-mass energy, so that the K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{gamma} data can be compared with direct measurements of the e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{gamma} reaction; no direct measurements exist for the e{sub +}e{sub -} {yields} K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0}{gamma} or e{sub +}e{sub -} {yields} K{sup +}K{sup -}K{sup +}K{sup -} reactions. Studying the structure of these events, we find contributions from a number of intermediate states, and we extract their cross sections where possible. In particular, we isolate the contribution from e{sup +}e{sup -} {yields} {phi}(1020)f{sub 0}(980) and study its structure near threshold. In the charmonium region, we observe the J/{psi} in all three final states and several intermediate states, as well as the {psi}/(2S) in some modes, and measure the corresponding branching fractions. We see no signal for the Y(4260) …
Date: May 4, 2007
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V. et al.
Object Type: Article
System: The UNT Digital Library
Multilayers for next generation x-ray sources (open access)

Multilayers for next generation x-ray sources

Multilayers are artificially layered structures that can be used to create optics and optical elements for a broad range of x-ray wavelengths, or can be optimized for other applications. The development of next generation x-ray sources (synchrotrons and x-ray free electron lasers) requires advances in x-ray optics. Newly developed multilayer-based mirrors and optical elements enabled efficient band-pass filtering, focusing and time resolved measurements in recent FLASH (Free Electron LASer in Hamburg) experiments. These experiments are providing invaluable feedback on the response of the multilayer structures to high intensity, short pulsed x-ray sources. This information is crucial to design optics for future x-ray free electron lasers and to benchmark computer codes that simulate damage processes.
Date: May 4, 2007
Creator: Bajt, S.; Chapman, H. N.; Spiller, E.; Hau-Riege, S.; Alameda, J.; Nelson, A. J. et al.
Object Type: Article
System: The UNT Digital Library
Analytic Models of Plausible Gravitational Lens Potentials (open access)

Analytic Models of Plausible Gravitational Lens Potentials

Gravitational lenses on galaxy scales are plausibly modeled as having ellipsoidal symmetry and a universal dark matter density profile, with a Sersic profile to describe the distribution of baryonic matter. Predicting all lensing effects requires knowledge of the total lens potential: in this work we give analytic forms for that of the above hybrid model. Emphasizing that complex lens potentials can be constructed from simpler components in linear combination, we provide a recipe for attaining elliptical symmetry in either projected mass or lens potential.We also provide analytic formulae for the lens potentials of Sersic profiles for integer and half-integer index. We then present formulae describing the gravitational lensing effects due to smoothly-truncated universal density profiles in cold dark matter model. For our isolated haloes the density profile falls off as radius to the minus fifth or seventh power beyond the tidal radius, functional forms that allow all orders of lens potential derivatives to be calculated analytically, while ensuring a non-divergent total mass. We show how the observables predicted by this profile differ from that of the original infinite-mass NFW profile. Expressions for the gravitational flexion are highlighted. We show how decreasing the tidal radius allows stripped haloes to be modeled, …
Date: May 4, 2007
Creator: Baltz, Edward A.; Marshall, Phil & Oguri, Masamune
Object Type: Article
System: The UNT Digital Library
Legal Issues Related to Prescription Drug Sales on the Internet (open access)

Legal Issues Related to Prescription Drug Sales on the Internet

This report details an overview of federal and state laws that regulate online pharmacies and physicians who prescribe drugs over the internet. Updated May 4, 2007.
Date: May 4, 2007
Creator: Burrows, Vanessa K.
Object Type: Report
System: The UNT Digital Library
CDZNTE ROOM-TEMPERATURE SEMICONDUCTOR GAMMA-RAY DETECTOR FOR NATIONAL-SECURITY APPLICATIONS. (open access)

CDZNTE ROOM-TEMPERATURE SEMICONDUCTOR GAMMA-RAY DETECTOR FOR NATIONAL-SECURITY APPLICATIONS.

One important mission of the Department of Energy's National Nuclear Security Administration is to develop reliable gamma-ray detectors to meet the widespread needs of users for effective techniques to detect and identify special nuclear- and radioactive-materials. Accordingly, the Nonproliferation and National Security Department at Brookhaven National Laboratory was tasked to evaluate existing technology and to develop improved room-temperature detectors based on semiconductors, such as CdZnTe (CZT). Our research covers two important areas: Improving the quality of CZT material, and exploring new CZT-based gamma-ray detectors. In this paper, we report on our recent findings from the material characterization and tests of actual CZT devices fabricated in our laboratory and from materials/detectors supplied by different commercial vendors. In particular, we emphasize the critical role of secondary phases in the current CZT material and issues in fabricating the CZT detectors, both of which affect their performance.
Date: May 4, 2007
Creator: Camarda, G. S.; Bolotnikov, A. E.; Cui, Y.; Hossain, A.; Kohman, K. T. & James, R. B.
Object Type: Article
System: The UNT Digital Library
HOLDUP MEASUREMENTS FOR THREE VISUAL EXAMINATION AND TRU REMEDIATION GLOVEBOX FACILITIES AT THE SAVANNAH RIVER SITE (open access)

HOLDUP MEASUREMENTS FOR THREE VISUAL EXAMINATION AND TRU REMEDIATION GLOVEBOX FACILITIES AT THE SAVANNAH RIVER SITE

Visual Examination (VE) gloveboxes are used to remediate transuranic waste (TRU) drums at three separate facilities at the Savannah River Site. Noncompliant items are removed before the drums undergo further characterization in preparation for shipment to the Waste Isolation Pilot Plant (WIPP). Maintaining the flow of drums through the remediation process is critical to the program's seven-days-per-week operation. Conservative assumptions are used to ensure that glovebox contamination from this continual operation is below acceptable limits. Holdup measurements using cooled HPGe spectrometers are performed in order to confirm that these assumptions are conservative. {sup 239}Pu is the main nuclide of interest; however, {sup 241}Pu, equilibrium {sup 237}Np/{sup 233}Pa and {sup 238}Pu (if detected) are typically assayed. At the Savannah River National Laboratory (SRNL) facility {sup 243,244,245}Cm are also generally observed and are always reported at either finite levels or at limits of detection. A complete assay at each of the three facilities includes a measure of TRU content in the gloveboxes and HEPA filters in the glovebox exhaust. This paper includes a description of the {gamma}-PHA acquisitions, of the modeling, and of the calculations of nuclide content. Because each of the remediation facilities is unique and ergonomically unfavorable to {gamma}-ray acquisitions, …
Date: May 4, 2007
Creator: Dewberry, R & Donald Pak, D
Object Type: Article
System: The UNT Digital Library
Quadractic Model of Thermodynamic States in SDF Explosions (open access)

Quadractic Model of Thermodynamic States in SDF Explosions

We study the thermodynamic states encountered during Shock-Dispersed-Fuel (SDF) explosions. Such explosions contain up to six components: three fuels (PETN, TNT and Aluminum) and their products corresponding to stoichiometric combustion with air. We establish the loci in thermodynamic state space that correctly describes the behavior of the components. Results are fit with quadratic functions that serve as fast equations of state suitable for 3D numerical simulations of SDF explosions.
Date: May 4, 2007
Creator: Kuhl, A L & Khasainov, B
Object Type: Article
System: The UNT Digital Library
Numerical Simulations of Thermobaric Explosions (open access)

Numerical Simulations of Thermobaric Explosions

A Model of the energy evolution in thermobaric explosions is presented. It is based on the two-phase formulation: conservation laws for the gas and particle phases along with inter-phase interaction terms. It incorporates a Combustion Model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gas dynamic fields. The Model takes into account both the afterburning of the detonation products of the booster with air, and the combustion of the fuel (Al or TNT detonation products) with air. Numerical simulations were performed for 1.5-g thermobaric explosions in five different chambers (volumes ranging from 6.6 to 40 liters and length-to-diameter ratios from 1 to 12.5). Computed pressure waveforms were very similar to measured waveforms in all cases - thereby proving that the Model correctly predicts the energy evolution in such explosions. The computed global fuel consumption {mu}(t) behaved as an exponential life function. Its derivative {dot {mu}}(t) represents the global rate of fuel consumption. It depends on the rate of turbulent mixing which controls the rate of energy release in thermobaric explosions.
Date: May 4, 2007
Creator: Kuhl, A L; Bell, J B; Beckner, V E & Khasainov, B
Object Type: Article
System: The UNT Digital Library
Fair Credit Reporting Act: Rights and Responsibilities (open access)

Fair Credit Reporting Act: Rights and Responsibilities

This report discusses about the Fair Credit Reporting Act (FCRA) that establishes a consumer's right. It also consists of Permissible Uses of Consumer Credit Reports and Consumer Rights.
Date: May 4, 2007
Creator: Lee, Margaret Mikyung
Object Type: Report
System: The UNT Digital Library
National Science Foundation: Major Research Equipment and Facility Construction (open access)

National Science Foundation: Major Research Equipment and Facility Construction

None
Date: May 4, 2007
Creator: Matthews, Christine M.
Object Type: Report
System: The UNT Digital Library
PArthENoPE: Public Algorithm Evaluating the Nucleosynthesis of Primordial Elements (open access)

PArthENoPE: Public Algorithm Evaluating the Nucleosynthesis of Primordial Elements

We describe a program for computing the abundances of light elements produced during Big Bang Nucleosynthesis which is publicly available at http://parthenope.na.infn.it/. Starting from nuclear statistical equilibrium conditions the program solves the set of coupled ordinary differential equations, follows the departure from chemical equilibrium of nuclear species, and determines their asymptotic abundances as function of several input cosmological parameters as the baryon density, the number of effective neutrino, the value of cosmological constant and the neutrino chemical potential.
Date: May 4, 2007
Creator: Pisanti, O.; Cirillo, A.; Esposito, S.; Iocco, F.; Mangano, G.; Miele, G. et al.
Object Type: Report
System: The UNT Digital Library
Waveforms Measured in Confined Thermobaric Explosion (open access)

Waveforms Measured in Confined Thermobaric Explosion

Experiments with 1.5-g Shock-Dispersed-Fuel (SDF) charges have been conducted in six different chambers. Both flake Aluminum and TNT were used as the fuel. Static pressure gauges on the chamber wall were the main diagnostic. Waveforms for explosions in air were significantly larger than those in nitrogen - thereby demonstrating a strong thermobaric (combustion) effect. This effect increases as the confinement volume decreases and the mixture richness approaches 1.
Date: May 4, 2007
Creator: Reichenbach, H; Neuwald, P & Kuhl, A L
Object Type: Article
System: The UNT Digital Library
DHS’s Max-HR Personnel System: Regulations on Classification, Pay, and Performance Management Compared With Current Law, and Implementation Plans (open access)

DHS’s Max-HR Personnel System: Regulations on Classification, Pay, and Performance Management Compared With Current Law, and Implementation Plans

This report compares the final regulations with current law under Title 5 of the United States Code and relevant regulations under Title 5 of the Code of Federal Regulations. Specifically, Subparts A (General Provisions), B (Classification), C (Pay and Pay Administration), and D (Performance Management) of the final regulations are examined.
Date: May 4, 2007
Creator: Schwemle, Barbara L.
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: GA-0545 (open access)

Texas Attorney General Opinion: GA-0545

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification: Whether district judges may authorize a county auditor to retain outside legal counsel for the purpose of responding to requests under the Public Information Act.
Date: May 4, 2007
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
80th Texas Legislature, Regular Session, House Bill 5, Chapter 19 (open access)

80th Texas Legislature, Regular Session, House Bill 5, Chapter 19

Bill introduced by the Texas House of Representatives relating to providing for a reduction of the limitation on the total amount of ad valorem taxes that may be imposed by a school district on the residence homesteads of the elderly or disabled to reflect any reduction in the school district's tax rate and protecting a school district against any resulting loss in local revenue.
Date: May 4, 2007
Creator: Texas. Legislature. House of Representatives.
Object Type: Legislative Document
System: The Portal to Texas History
80th Texas Legislature, Regular Session, House Concurrent Resolution 26 (open access)

80th Texas Legislature, Regular Session, House Concurrent Resolution 26

Concurrent resolution introduced by the Texas House of Representatives and Senate relating to in memory of the Honorable Frank Madla of San Antonio.
Date: May 4, 2007
Creator: Texas. Legislature. House of Representatives.
Object Type: Legislative Document
System: The Portal to Texas History
80th Texas Legislature, Regular Session, House Concurrent Resolution 158 (open access)

80th Texas Legislature, Regular Session, House Concurrent Resolution 158

Concurrent resolution introduced by the Texas House of Representatives and Senate relating to congratulating the Mart Panthers football team on winning the 2006 2A State Championship.
Date: May 4, 2007
Creator: Texas. Legislature. House of Representatives.
Object Type: Legislative Document
System: The Portal to Texas History
80th Texas Legislature, Regular Session, House Concurrent Resolution 167 (open access)

80th Texas Legislature, Regular Session, House Concurrent Resolution 167

Concurrent resolution introduced by the Texas House of Representatives and Senate relating to recognizing the 2007 and 2008 appointments of State Poet Laureate, State Musician, and State Visual Artists.
Date: May 4, 2007
Creator: Texas. Legislature. House of Representatives.
Object Type: Legislative Document
System: The Portal to Texas History
80th Texas Legislature, Regular Session, House Concurrent Resolution 170 (open access)

80th Texas Legislature, Regular Session, House Concurrent Resolution 170

Concurrent resolution introduced by the Texas House of Representatives and Senate relating to commemorating the Texas Maritime Museum's 20th anniversary as the official State Maritime Museum of Texas.
Date: May 4, 2007
Creator: Texas. Legislature. House of Representatives.
Object Type: Legislative Document
System: The Portal to Texas History
80th Texas Legislature, Regular Session, Senate Bill 192, Chapter 23 (open access)

80th Texas Legislature, Regular Session, Senate Bill 192, Chapter 23

Bill introduced by the Texas Senate relating to the Texas Mutual Insurance Company and the application of certain statutes to the Texas Mutual Insurance Company.
Date: May 4, 2007
Creator: Texas. Legislature. Senate.
Object Type: Legislative Document
System: The Portal to Texas History
80th Texas Legislature, Regular Session, Senate Bill 213, Chapter 24 (open access)

80th Texas Legislature, Regular Session, Senate Bill 213, Chapter 24

Bill introduced by the Texas Senate relating to the authority of certain counties to impose a county hotel occupancy tax and to the rate of the tax.
Date: May 4, 2007
Creator: Texas. Legislature. Senate.
Object Type: Legislative Document
System: The Portal to Texas History
80th Texas Legislature, Regular Session, Senate Bill 229, Chapter 25 (open access)

80th Texas Legislature, Regular Session, Senate Bill 229, Chapter 25

Bill introduced by the Texas Senate relating to the seal of a district court and the signature of the district clerk used on process issued by the court.
Date: May 4, 2007
Creator: Texas. Legislature. Senate.
Object Type: Legislative Document
System: The Portal to Texas History