Real Earnings, Health Insurance and Pension Coverage, and the Distribution of Earnings, 1979-2009 (open access)

Real Earnings, Health Insurance and Pension Coverage, and the Distribution of Earnings, 1979-2009

This report analyzes the real weekly earnings from 1979 to 2009 of U.S. workers, including worker pay and fringe benefits, such as employer contributions for health insurance or to a retirement plan.
Date: July 6, 2011
Creator: Mayer, Gerald
Object Type: Report
System: The UNT Digital Library
Libya: Unrest and U.S. Policy (open access)

Libya: Unrest and U.S. Policy

None
Date: July 6, 2011
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Triple Modulator-Chicane Scheme for Seeding Sub-Nanometer X-Ray Free Electron Lasers (open access)

Triple Modulator-Chicane Scheme for Seeding Sub-Nanometer X-Ray Free Electron Lasers

We propose a novel triple modulator-chicane (TMC) scheme to convert external input seed to shorter wavelengths. In the scheme high power seed lasers are used in the first and third modulator while only very low power seed is used in the second modulator. By properly choosing the parameters of the lasers and chicanes, we show that ultrahigh harmonics can be generated in the TMC scheme while simultaneously keeping the energy spread growth much smaller than beam's initial slice energy spread. As an example we show the feasibility of generating significant bunching at 1 nm and below from a low power ({approx} 100 kW) high harmonic generation seed at 20 nm assisted by two high power ({approx} 100 MW) UV lasers at 200 nm while keeping the energy spread growth within 40%. The supreme up-frequency conversion efficiency of the proposed TMC scheme together with its unique advantage in maintaining beam energy spread opens new opportunities for generating fully coherent x-rays at sub-nanometer wavelength from external seeds.
Date: July 6, 2011
Creator: Xiang, Dao & Stupakov, Gennady
Object Type: Article
System: The UNT Digital Library
Calibration of LSST Instrumental and Atmospheric Photometric Passbands (open access)

Calibration of LSST Instrumental and Atmospheric Photometric Passbands

The Large Synoptic Survey Telescope (LSST) will continuously image the entire sky visible from Cerro Pachon in northern Chile every 3-4 nights throughout the year. The LSST will provide data for a broad range of science investigations that require better than 1% photometric precision across the sky (repeatability and uniformity) and a similar accuracy of measured broadband color. The fast and persistent cadence of the LSST survey will significantly improve the temporal sampling rate with which celestial events and motions are tracked. To achieve these goals, and to optimally utilize the observing calendar, it will be necessary to obtain excellent photometric calibration of data taken over a wide range of observing conditions - even those not normally considered 'photometric'. To achieve this it will be necessary to routinely and accurately measure the full optical passband that includes the atmosphere as well as the instrumental telescope and camera system. The LSST mountain facility will include a new monochromatic dome illumination projector system to measure the detailed wavelength dependence of the instrumental passband for each channel in the system. The facility will also include an auxiliary spectroscopic telescope dedicated to measurement of atmospheric transparency at all locations in the sky during LSST …
Date: July 6, 2011
Creator: Burke, David L.; Axelrod, T.; Barrau, Aurelien; Baumont, Sylvain; Blondin, Stephane; Claver, Chuck et al.
Object Type: Article
System: The UNT Digital Library
Scattering and; Delay, Scale, and Sum Migration (open access)

Scattering and; Delay, Scale, and Sum Migration

How do we see? What is the mechanism? Consider standing in an open field on a clear sunny day. In the field are a yellow dog and a blue ball. From a wave-based remote sensing point of view the sun is a source of radiation. It is a broadband electromagnetic source which, for the purposes of this introduction, only the visible spectrum is considered (approximately 390 to 750 nanometers or 400 to 769 TeraHertz). The source emits an incident field into the known background environment which, for this example, is free space. The incident field propagates until it strikes an object or target, either the yellow dog or the blue ball. The interaction of the incident field with an object results in a scattered field. The scattered field arises from a mis-match between the background refractive index, considered to be unity, and the scattering object refractive index ('yellow' for the case of the dog, and 'blue' for the ball). This is also known as an impedance mis-match. The scattering objects are referred to as secondary sources of radiation, that radiation being the scattered field which propagates until it is measured by the two receivers known as 'eyes'. The eyes focus …
Date: July 6, 2011
Creator: Lehman, S K
Object Type: Report
System: The UNT Digital Library
LIP: The Livermore Interpolation Package, Version 1.4 (open access)

LIP: The Livermore Interpolation Package, Version 1.4

This report describes LIP, the Livermore Interpolation Package. Because LIP is a stand-alone version of the interpolation package in the Livermore Equation of State (LEOS) access library, the initials LIP alternatively stand for the 'LEOS Interpolation Package'. LIP was totally rewritten from the package described in [1]. In particular, the independent variables are now referred to as x and y, since the package need not be restricted to equation of state data, which uses variables {rho} (density) and T (temperature). LIP is primarily concerned with the interpolation of two-dimensional data on a rectangular mesh. The interpolation methods provided include piecewise bilinear, reduced (12-term) bicubic, and bicubic Hermite (biherm). There is a monotonicity-preserving variant of the latter, known as bimond. For historical reasons, there is also a biquadratic interpolator, but this option is not recommended for general use. A birational method was added at version 1.3. In addition to direct interpolation of two-dimensional data, LIP includes a facility for inverse interpolation (at present, only in the second independent variable). For completeness, however, the package also supports a compatible one-dimensional interpolation capability. Parametric interpolation of points on a two-dimensional curve can be accomplished by treating the components as a pair of one-dimensional …
Date: July 6, 2011
Creator: Fritsch, F N
Object Type: Report
System: The UNT Digital Library
Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds (open access)

Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds

The 'Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds' project focused extensively on the analysis and utilization of water vapor and aerosol profiles derived from the ARM Raman lidar at the Southern Great Plains ARM site. A wide range of different tasks were performed during this project, all of which improved quality of the data products derived from the lidar or advanced the understanding of atmospheric processes over the site. These activities included: upgrading the Raman lidar to improve its sensitivity; participating in field experiments to validate the lidar aerosol and water vapor retrievals; using the lidar aerosol profiles to evaluate the accuracy of the vertical distribution of aerosols in global aerosol model simulations; examining the correlation between relative humidity and aerosol extinction, and how these change, due to horizontal distance away from cumulus clouds; inferring boundary layer turbulence structure in convective boundary layers from the high-time-resolution lidar water vapor measurements; retrieving cumulus entrainment rates in boundary layer cumulus clouds; and participating in a field experiment that provided data to help validate both the entrainment rate retrievals and the turbulent profiles derived from lidar observations.
Date: July 6, 2011
Creator: Turner, David, D. & Ferrare, Richard, A.
Object Type: Report
System: The UNT Digital Library
DEVELOPMENT OF A SENSOR NETWORK TEST BED FOR ISD MATERIALS AND STRUCUTRAL CONDITION MONITORING (open access)

DEVELOPMENT OF A SENSOR NETWORK TEST BED FOR ISD MATERIALS AND STRUCUTRAL CONDITION MONITORING

The P Reactor at the Savannah River Site is one of the first reactor facilities in the US DOE complex that has been placed in its end state through in situ decommissioning (ISD). The ISD end state consists of a grout-filled concrete civil structure within the concrete frame of the original building. To evaluate the feasibility and utility of remote sensors to provide verification of ISD system conditions and performance characteristics, an ISD Sensor Network Test Bed has been designed and deployed at the Savannah River National Laboratory. The test bed addresses the DOE-EM Technology Need to develop a remote monitoring system to determine and verify ISD system performance. Commercial off-the-shelf sensors have been installed on concrete blocks taken from walls of the P Reactor Building. Deployment of this low-cost structural monitoring system provides hands-on experience with sensor networks. The initial sensor system consists of: (1) Groutable thermistors for temperature and moisture monitoring; (2) Strain gauges for crack growth monitoring; (3) Tiltmeters for settlement monitoring; and (4) A communication system for data collection. Preliminary baseline data and lessons learned from system design and installation and initial field testing will be utilized for future ISD sensor network development and deployment.
Date: July 6, 2011
Creator: Zeigler, K.; Ferguson, B.; Karapatakis, D.; Herbst, C. & Stripling, C.
Object Type: Report
System: The UNT Digital Library
MARIANE: MApReduce Implementation Adapted for HPC Environments (open access)

MARIANE: MApReduce Implementation Adapted for HPC Environments

MapReduce is increasingly becoming a popular framework, and a potent programming model. The most popular open source implementation of MapReduce, Hadoop, is based on the Hadoop Distributed File System (HDFS). However, as HDFS is not POSIX compliant, it cannot be fully leveraged by applications running on a majority of existing HPC environments such as Teragrid and NERSC. These HPC environments typicallysupport globally shared file systems such as NFS and GPFS. On such resourceful HPC infrastructures, the use of Hadoop not only creates compatibility issues, but also affects overall performance due to the added overhead of the HDFS. This paper not only presents a MapReduce implementation directly suitable for HPC environments, but also exposes the design choices for better performance gains in those settings. By leveraging inherent distributed file systems' functions, and abstracting them away from its MapReduce framework, MARIANE (MApReduce Implementation Adapted for HPC Environments) not only allows for the use of the model in an expanding number of HPCenvironments, but also allows for better performance in such settings. This paper shows the applicability and high performance of the MapReduce paradigm through MARIANE, an implementation designed for clustered and shared-disk file systems and as such not dedicated to a specific …
Date: July 6, 2011
Creator: Fadika, Zacharia; Dede, Elif; Govindaraju, Madhusudhan & Ramakrishnan, Lavanya
Object Type: Article
System: The UNT Digital Library
Measurement of Thermal Dependencies of PBG Fiber Properties (open access)

Measurement of Thermal Dependencies of PBG Fiber Properties

Photonic crystal fibers (PCFs) represent a class of optical fibers which have a wide spectrum of applications in the telecom and sensing industries. Currently, the Advanced Accelerator Research Department at SLAC is developing photonic bandgap particle accelerators, which are photonic crystal structures with a central defect used to accelerate electrons and achieve high longitudinal electric fields. Extremely compact and less costly than the traditional accelerators, these structures can support higher accelerating gradients and will open a new era in high energy physics as well as other fields of science. Based on direct laser acceleration in dielectric materials, the so called photonic band gap accelerators will benefit from mature laser and semiconductor industries. One of the key elements to direct laser acceleration in hollow core PCFs, is maintaining thermal and structural stability. Previous simulations demonstrate that accelerating modes are sensitive to the geometry of the defect region and the variations in the effective index. Unlike the telecom modes (for which over 95% of the energy propagates in the hollow core) most of the power of these modes is located in the glass at the periphery of the central hole which has a higher thermal constant than air ({gamma}{sub SiO{sub 2}} = …
Date: July 6, 2011
Creator: Laouar, Rachik
Object Type: Article
System: The UNT Digital Library
Synthesis and characterization of a nanocrystalline diamond aerogel (open access)

Synthesis and characterization of a nanocrystalline diamond aerogel

Aerogel materials have myriad scientific and technological applications due to their large intrinsic surface areas and ultralow densities. However, creating a nanodiamond aerogel matrix has remained an outstanding and intriguing challenge. Here we report the high-pressure, high-temperature synthesis of a diamond aerogel from an amorphous carbon aerogel precursor using a laser-heated diamond anvil cell. Neon is used as a chemically inert, near-hydrostatic pressure medium that prevents collapse of the aerogel under pressure by conformally filling the aerogel's void volume. Electron and X-ray spectromicroscopy confirm the aerogel morphology and composition of the nanodiamond matrix. Time-resolved photoluminescence measurements of recovered material reveal the formation of both nitrogen- and silicon- vacancy point-defects, suggesting a broad range of applications for this nanocrystalline diamond aerogel.
Date: July 6, 2011
Creator: Pauzauskie, Peter J.; Crowhurst, Jonathan C.; Worsley, Marcus A.; Laurence, Ted A.; Kilcoyne, A. L. David; Wang, Yinmin et al.
Object Type: Article
System: The UNT Digital Library
R^4 Counterterm and E_{7(7)} Symmetry in Maximal Supergravity (open access)

R^4 Counterterm and E_{7(7)} Symmetry in Maximal Supergravity

The coefficient of a potential R{sup 4} counterterm in N = 8 supergravity has been shown previously to vanish in an explicit three-loop calculation. The R{sup 4} term respects N = 8 supersymmetry; hence this result poses the question of whether another symmetry could be responsible for the cancellation of the three-loop divergence. In this article we investigate possible restrictions from the coset symmetry E{sub 7(7)}/SU(8), using a double-soft scalar limit relation derived recently by Arkani-Hamed et al. In order to implement the relation, we make use of the fact that the R{sup 4} term occurs in the low-energy expansion of closed-string tree-level amplitudes. We find that the matrix elements of R{sup 4} that we investigated all obey the double-soft scalar limit relation, suggesting that E{sub 7(7)} is also respected by the R{sup 4} term.
Date: July 6, 2011
Creator: Broedel, Johannes; /Potsdam, Max Planck Inst. /Leibniz U., Hannover & Dixon, Lance J.
Object Type: Article
System: The UNT Digital Library
Selenium hyperaccumulation offers protection from cell disruptor herbivores (open access)

Selenium hyperaccumulation offers protection from cell disruptor herbivores

Hyperaccumulation, the rare capacity of certain plant species to accumulate toxic trace elements to levels several orders of magnitude higher than other species growing on the same site, is thought to be an elemental defense mechanism against herbivores and pathogens. Previous research has shown that selenium (Se) hyperaccumulation protects plants from a variety of herbivores and pathogens. Selenium hyperaccumulating plants sequester Se in discrete locations in the leaf periphery, making them potentially more susceptible to some herbivore feeding modes than others. In this study we investigate the protective function of Se in the Se hyperaccumulators Stanleya pinnata and Astragalus bisulcatus against two cell disrupting herbivores, the western flower thrips (Frankliniella occidentalis) and the two-spotted spider mite (Tetranychus urticae). Astragalus bisulcatus and S. pinnata with high Se concentrations (greater than 650 mg Se kg{sup -1}) were less subject to thrips herbivory than plants with low Se levels (less than 150 mg Se kg{sup -1}). Furthermore, in plants containing elevated Se levels, leaves with higher concentrations of Se suffered less herbivory than leaves with less Se. Spider mites also preferred to feed on low-Se A. bisulcatus and S. pinnata plants rather than high-Se plants. Spider mite populations on A. bisulcatus decreased after …
Date: July 6, 2011
Creator: Quinn, Colin F; Freeman, John L; Reynolds, Ray JB; Cappa, Jennifer J; Fakra, Sirine C; Marcus, Matthew A et al.
Object Type: Article
System: The UNT Digital Library
Reverse engineering the ancient ceramic technology based on X-ray fluorescence spectromicroscopy (open access)

Reverse engineering the ancient ceramic technology based on X-ray fluorescence spectromicroscopy

We present results of X-ray fluorescence (XRF) microprobe analyses of ancient ceramic cross-sections aiming at deciphering the different firing protocols used for their production. Micro-focused XRF elemental mapping, Fe chemical mapping and Fe K-edge X-ray absorption near edge structure spectroscopy were performed on pre-sigillata ceramics from southern Gaul, and terra Sigillata vessels from Italy and southern Gaul. Pieces from the different workshops and regions showed significant difference in the starting clay material, clay conditioning and kiln firing condition. By contrast, sherds from the same workshop exhibited more subtle differences and possible misfirings. Understanding the precise firing conditions and protocols would allow recreation of kilns for various productions. Furthermore, evolution and modification of kiln design would shed some light on how ancient potters devised solutions to diverse technological problems they encountered.
Date: July 6, 2011
Creator: Sciau, Philippe; Leon, Yoanna; Goudeau, Philippe; Fakra, Sirine C.; Webb, Sam & Mehta, Apurva
Object Type: Article
System: The UNT Digital Library
A Linear Theory of Microwave Instability in Electron Storage Rings (open access)

A Linear Theory of Microwave Instability in Electron Storage Rings

The well-known Haissinski distribution provides a stable equilibrium of longitudinal beam distribution in electron storage rings below a threshold current. Yet, how to accurately determine this threshold, above which the Haissinski distribution becomes unstable, is not firmly established in theory. In this paper, we will show how to apply the Laguerre polynomials in an analysis of this stability that are associated with the potential-well distortion. Our approach provides an alternative to the discretization method proposed by Oide and Yokoya. Moreover, it reestablishes an essential connection to the theory of mode coupling originated by Sacherer. Our new and self-consistent method is applied to study the microwave instability driven by commonly known impedances, including coherent synchrotron radiation in free space.
Date: July 6, 2011
Creator: Cai, Yunhai
Object Type: Article
System: The UNT Digital Library
Afghanistan: Politics, Elections, and Government Performance (open access)

Afghanistan: Politics, Elections, and Government Performance

This report discusses the current political state of Afghanistan, as well as the Afghan government. This report also discusses Afghanistan's relationship with the United States, particularly U.S. efforts to urge President Hamid Karzai, to address corruption within the Afghan government. The report also includes discussion of election fraud and corruption in Afghanistan.
Date: July 6, 2011
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library
Closing the Guantanamo Detention Center: Legal Issues (open access)

Closing the Guantanamo Detention Center: Legal Issues

This report provides an overview of major legal issues likely to arise as a result of executive and legislative action to close the Guantanamo detention facility.
Date: July 6, 2011
Creator: Mason, R. Chuck; Liu, Edward C.; Garcia, Michael J. & Elsea, Jennifer K.
Object Type: Report
System: The UNT Digital Library
Coast Guard Polar Icebreaker Modernization: Background, Issues, and Options for Congress (open access)

Coast Guard Polar Icebreaker Modernization: Background, Issues, and Options for Congress

This report provides information about the Background, Issues, and Options for Congress on Coast Guard Polar Icebreaker Modernization. Coast Guard breakers perform a variety of missions supporting the U.S interests in polar regions.
Date: July 6, 2011
Creator: O'Rourke, Ronald
Object Type: Report
System: The UNT Digital Library
HYBRID SULFUR CYCLE FLOWSHEETS FOR HYDROGEN PRODUCTION USING HIGH-TEMPERATURE GAS-COOLED REACTORS (open access)

HYBRID SULFUR CYCLE FLOWSHEETS FOR HYDROGEN PRODUCTION USING HIGH-TEMPERATURE GAS-COOLED REACTORS

Two hybrid sulfur (HyS) cycle process flowsheets intended for use with high-temperature gas-cooled reactors (HTGRs) are presented. The flowsheets were developed for the Next Generation Nuclear Plant (NGNP) program, and couple a proton exchange membrane (PEM) electrolyzer for the SO2-depolarized electrolysis step with a silicon carbide bayonet reactor for the high-temperature decomposition step. One presumes an HTGR reactor outlet temperature (ROT) of 950 C, the other 750 C. Performance was improved (over earlier flowsheets) by assuming that use of a more acid-tolerant PEM, like acid-doped poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI), instead of Nafion{reg_sign}, would allow higher anolyte acid concentrations. Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950 C case, dropping to 39.9% for the 750 C case.
Date: July 6, 2011
Creator: Gorensek, M.
Object Type: Article
System: The UNT Digital Library
Seismic Attenuation, Event Discrimination, Magnitude and Yield Estimation, and Capability Analysis (open access)

Seismic Attenuation, Event Discrimination, Magnitude and Yield Estimation, and Capability Analysis

None
Date: July 6, 2011
Creator: Pasyanos, M E; Walter, W R; Matzel, E M; Gok, R; Dodge, D A; Ford, S R et al.
Object Type: Article
System: The UNT Digital Library
Asymmetry and Risk (open access)

Asymmetry and Risk

None
Date: July 6, 2011
Creator: Goodwin, B T
Object Type: Article
System: The UNT Digital Library
Is Biopower Carbon Neutral? (open access)

Is Biopower Carbon Neutral?

This report assesses the variables involved in determining whether or not biopower (i.e., electricity generated from biomass) is a carbon-neutral alternative to fossil fuels as a way to help meet meet U.S. energy demands and reduce U.S. greenhouse gas (GHG) emissions. It includes information about the biomass carbon cycle, GHG accounting for biopower production, recent developments affecting the assessment, and overview of whether or not it can be considered carbon neutral, and legislative implications.
Date: July 6, 2011
Creator: Bracmort, Kelsi
Object Type: Report
System: The UNT Digital Library
Considerations for a Catastrophic Declaration: Issues and Analysis (open access)

Considerations for a Catastrophic Declaration: Issues and Analysis

This report examines concerns expressed by policymakers and experts that current Stafford Act declarations are inadequate to respond to, and recover from, highly destructive events. It presents the arguments for and against amending the act to add a catastrophic declaration amendment. This report also includes data analyses of past and potential disasters to determine what incidents might be deemed as catastrophic, and explores alternative policy options that might obviate the need for catastrophic declarations.
Date: July 6, 2011
Creator: Lindsay, Bruce R. & McCarthy, Francis X.
Object Type: Report
System: The UNT Digital Library
Federal Register, Volume 76, Number 129, July 6, 2011, Pages 39245-39762 (open access)

Federal Register, Volume 76, Number 129, July 6, 2011, Pages 39245-39762

Daily publication of the U.S. Office of the Federal Register contains rules and regulations, proposed legislation and rule changes, and other notices, including "Presidential proclamations and Executive Orders, Federal agency documents having general applicability and legal effect, documents required to be published by act of Congress, and other Federal agency documents of public interest" (p. ii). Table of Contents starts on page iii.
Date: July 6, 2011
Creator: United States. Office of the Federal Register.
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library