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Double-Dip Recession: Previous Experience and Current Prospect (open access)

Double-Dip Recession: Previous Experience and Current Prospect

This report discusses factors suggesting an increased risk of a double-dip recession. A double-dip or W-shaped recession occurs when the economy emerges from a recession, has a short period of growth, but then, still well short of a full recovery, falls back into recession. It also discusses other factors that suggest economic recovery will continue. It presents the U.S. historical experience with double-dip recessions. It examines the role of deleveraging by households and businesses in the aftermath of the recent financial crisis in shaping the likely pace of economic recovery. The report concludes with a look at current economic projections.
Date: June 19, 2012
Creator: Elwell, Craig K.
Object Type: Report
System: The UNT Digital Library
Interim Report on the Optimization and Feasibility Studies for the Neutron Detection without Helium-3 Project (open access)

Interim Report on the Optimization and Feasibility Studies for the Neutron Detection without Helium-3 Project

This report provides the status and results of the first year's effort in modeling and simulation to investigate alternatives to helium-3 for neutron detection in safeguards applications.
Date: March 19, 2012
Creator: Ely, James H.
Object Type: Report
System: The UNT Digital Library
Fact Sheet: The FY2013 State and Foreign Operations Budget Request (open access)

Fact Sheet: The FY2013 State and Foreign Operations Budget Request

On February 13, 2012, the Obama Administration submitted its FY2013 budget request, including $54.7 billion for State Department, Foreign Operations, and Related Appropriations. Of the total request, $18.6 billion is for programs funded through the State operations and related agencies (a 4.6% increase over FY2012 estimates), and $36.1 billion is for foreign operations (a 0.1% increase over FY2012 estimates). This fact sheet provides a brief overview of the request.
Date: March 19, 2012
Creator: Epstein, Susan B.; Lawson, Marian Leonardo & Tiersky, Alex L.
Object Type: Report
System: The UNT Digital Library
Quantifying advective and nonstationary effects on eddy fluxes in the AmeriFlux network (open access)

Quantifying advective and nonstationary effects on eddy fluxes in the AmeriFlux network

Our goal was to study the flows within and above of a forested area and assess the degree to which horizontal subcanopy motions transport significant amounts of CO2. This process can explain why ecosystem respiration appears to be underestimated on calm nights. It is essential to understand the physical and biological mechanisms that determine relevant processes that occur on these ‘suspect’ nights.
Date: December 19, 2012
Creator: Fitzjarrald, David R.
Object Type: Report
System: The UNT Digital Library
Aerosol Best Estimate Value-Added Product (open access)

Aerosol Best Estimate Value-Added Product

The objective of the Aerosol Best Estimate (AEROSOLBE) value-added product (VAP) is to provide vertical profiles of aerosol extinction, single scatter albedo, asymmetry parameter, and Angstroem exponents for the atmospheric column above the Central Facility at the ARM Southern Great Plains (SGP) site. We expect that AEROSOLBE will provide nearly continuous estimates of aerosol optical properties under a range of conditions (clear, broken clouds, overcast clouds, etc.). The primary requirement of this VAP was to provide an aerosol data set as continuous as possible in both time and height for the Broadband Heating Rate Profile (BBHRP) VAP in order to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Even though BBHRP has been completed, AEROSOLBE results are very valuable for environmental, atmospheric, and climate research.
Date: July 19, 2012
Creator: Flynn, C; Turner, D; Koontz, A; Chand, D & Sivaraman, C
Object Type: Report
System: The UNT Digital Library
Parametric Explosion Spectral Model (open access)

Parametric Explosion Spectral Model

Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never before occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. Explosion spectra can be fit with similar spectral models whose parameters are then correlated with near-source geology and containment conditions. We observe a correlation of high gas-porosity (low-strength) with increased spectral slope. The relationship between the parametric equations and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source.
Date: January 19, 2012
Creator: Ford, S R & Walter, W R
Object Type: Report
System: The UNT Digital Library
Characteristics of Short Wavelength Compressional Alfven Eigenmodes (open access)

Characteristics of Short Wavelength Compressional Alfven Eigenmodes

Most Alfvenic activity in the frequency range between Toroidal Alfven Eigenmodes and roughly one half of the ion cyclotron frequency on NSTX [M. Ono, et al., Nucl. Fusion 40 (2000) 557], that is, approximately 0.3 MHz up to ≈ 1.2 MHz, are modes propagating counter to the neutral beam ions. These have been modeled as Compressional and Global Alfven Eigenmodes (CAE and GAE) and are excited through a Doppler-shifted cyclotron resonance with the beam ions. There is also a class of co-propagating modes at higher frequency than the counter-propagating CAE and GAE. These modes have been identified as CAE, and are seen mostly in the company of a low frequency, n=1 kink-like mode. In this paper we present measurements of the spectrum of these high frequency CAE (hfCAE), and their mode structure. We compare those measurements to a simple model of CAE and present evidence of a curious non-linear coupling of the hfCAE and the low frequency kink-like mode.
Date: December 19, 2012
Creator: Fredrickson, E. D.; Podesta, M.; Bortolon, A.; Crocker, N. A.; Gerhardt, S. P.; Bell, R. E. et al.
Object Type: Report
System: The UNT Digital Library
Upgrade scenario for the RHIC collimation system (open access)

Upgrade scenario for the RHIC collimation system

The RHIC collimation system is used to reduce background levels in both STAR and PHENIX detectors. With a push for higher luminosity in the near future, it becomes critical to check if and how the level of performance of the collimators can be improved. The following reviews a proposal for additional collimators placed further downstream of the current system and designed to intercept the tertiary halo coming out of the IR8 insertion before it can reach the triplet quadrupoles in either STAR or PHENIX. Simulations have been peformed to quantify the efficiency of additional collimator jaws in RHIC. Each figure presented in this article clearly shows that the additional mask collimators provide the expected reduction in losses around the machine, and especially to the incoming triplet to the STAR experiment (IP6), for the Yellow beam as much as for the Blue beam. Looking at compiled statistics for all three working point cases studied, proton losses around the machine are reduced by roughly one order of magnitude: at most a factor 30 for magnet losses, and at most a factor 40 for losses in spaces between magnets.
Date: January 19, 2012
Creator: G., Robert-Demolaize; Drees&#44 & A.
Object Type: Report
System: The UNT Digital Library
Moisture desorption rates from TATB-formulations: experiments and kinetic models (open access)

Moisture desorption rates from TATB-formulations: experiments and kinetic models

None
Date: January 19, 2012
Creator: Glascoe, E. A.; Dinh, L. N.; Small, W. & Overturf, G. E.
Object Type: Article
System: The UNT Digital Library
Modeling Ion-Exchange Processing With Spherical Resins For Cesium Removal (open access)

Modeling Ion-Exchange Processing With Spherical Resins For Cesium Removal

The spherical Resorcinol-Formaldehyde and hypothetical spherical SuperLig(r) 644 ion-exchange resins are evaluated for cesium removal from radioactive waste solutions. Modeling results show that spherical SuperLig(r) 644 reduces column cycling by 50% for high-potassium solutions. Spherical Resorcinol Formaldehyde performs equally well for the lowest-potassium wastes. Less cycling reduces nitric acid usage during resin elution and sodium addition during resin regeneration, therefore, significantly decreasing life-cycle operational costs. A model assessment of the mechanism behind ''cesium bleed'' is also conducted. When a resin bed is eluted, a relatively small amount of cesium remains within resin particles. Cesium can bleed into otherwise decontaminated product in the next loading cycle. The bleed mechanism is shown to be fully isotherm-controlled vs. mass transfer controlled. Knowledge of residual post-elution cesium level and resin isotherm can be utilized to predict rate of cesium bleed in a mostly non-loaded column. Overall, this work demonstrates the versatility of the ion-exchange modeling to study the effects of resin characteristics on processing cycles, rates, and cold chemical consumption. This evaluation justifies further development of a spherical form of the SL644 resin.
Date: September 19, 2012
Creator: Hang, T.; Nash, C. A. & Aleman, S. E.
Object Type: Article
System: The UNT Digital Library
The Cornell-SLAC Pixel Array Detector at LCLS (open access)

The Cornell-SLAC Pixel Array Detector at LCLS

None
Date: November 19, 2012
Creator: Hart, P.; Boutet, S.; Carini, G.; Dragone, A.; Duda, B.; Freytag, D. et al.
Object Type: Article
System: The UNT Digital Library
CHARACTERIZATION OF TANK 16H ANNULUS SAMPLES PART II: LEACHING RESULTS (open access)

CHARACTERIZATION OF TANK 16H ANNULUS SAMPLES PART II: LEACHING RESULTS

The closure of Tank 16H will require removal of material from the annulus of the tank. Samples from Tank 16H annulus were characterized and tested to provide information to evaluate various alternatives for removing the annulus waste. The analysis found all four annulus samples to be composed mainly of Si, Na, and Al and lesser amounts of other elements. The XRD data indicate quartz (SiO{sub 2}) and sodium aluminum nitrate silicate hydrate (Na{sub 8}(Al{sub 6}Si{sub 6}O{sub 24})(NO{sub 3}){sub 2}.4H{sub 2}O) as the predominant crystalline mineral phases in the samples. The XRD data also indicate the presence of crystalline sodium nitrate (NaNO{sub 3}), sodium nitrite (NaNO{sub 2}), gibbsite (Al(OH){sub 3}), hydrated sodium bicarbonate (Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O), and muscovite (KAl{sub 2}(AlSi{sub 3}O{sub 10})(OH){sub 2}). Based on the weight of solids remaining at the end of the test, the water leaching test results indicate 20-35% of the solids dissolved after three contacts with an approximately 3:1 volume of water at 45 C. The chemical analysis of the leachates and the XRD results of the remaining solids indicate sodium salts of nitrate, nitrite, sulfate, and possibly carbonate/bicarbonate make up the majority of the dissolved material. The majority of these salts were dissolved …
Date: June 19, 2012
Creator: Hay, M. & Reboul, S.
Object Type: Report
System: The UNT Digital Library
High-Power Microwave Switch Employing Electron Beam Triggering (open access)

High-Power Microwave Switch Employing Electron Beam Triggering

A high-power active microwave pulse compressor is described that modulates the quality factor Q of the energy storage cavity by a new means involving mode conversion controlled by a triggered electron-beam discharge through a switch cavity. The electron beam is emitted from a diamond-coated molybdenum cathode. This report describes the principle of operation, the design of the switch, the configuration used for the test, and the experimental results. The pulse compressor produced output pulses with 140 - “165 MW peak power, power gain of 16 - 20, and pulse duration of 16 - 20 ns at a frequency of 11.43 GHz.
Date: September 19, 2012
Creator: Hirshfield, Jay L.
Object Type: Report
System: The UNT Digital Library
A Critical Appraisal of NLO+PS Matching Methods (open access)

A Critical Appraisal of NLO+PS Matching Methods

In this publication, uncertainties in and differences between the MC{at}NLO and POWHEG methods for matching next-to-leading order QCD calculations with parton showers are discussed. Implementations of both algorithms within the event generator SHERPA are employed to assess the impact on a representative selection of observables. In the MC{at}NLO approach a phase space restriction has been added to subtraction and parton shower, which allows to vary in a transparent way the amount of non-singular radiative corrections that are exponentiated. Effects on various observables are investigated, using the production of a Higgs boson in gluon fusion, with or without an associated jet, as a benchmark process. The case of H+jet production is presented for the first time in an NLO+PS matched simulation. Uncertainties due to scale choices and non-perturbative effects are explored in the production of W{sup {+-}} and Z bosons in association with a jet. Corresponding results are compared to data from the Tevatron and LHC experiments.
Date: March 19, 2012
Creator: Hoeche, Stefan; Krauss, Frank; Schonherr, Marek & Siegert, Frank
Object Type: Article
System: The UNT Digital Library
Task 1—Steam Oxidation (NETL-US) (open access)

Task 1—Steam Oxidation (NETL-US)

None
Date: April 19, 2012
Creator: Holcomb, Gordon R. & Tylczak, Joseph
Object Type: Article
System: The UNT Digital Library
Task 2—Materials for Advanced Boiler and Oxy-combustion Systems (NETL-US) (open access)

Task 2—Materials for Advanced Boiler and Oxy-combustion Systems (NETL-US)

None
Date: April 19, 2012
Creator: Holcomb, Gordon R. & Tylczak, Joseph
Object Type: Article
System: The UNT Digital Library
Sensitivity analysis of large system of chemical kinetic parameters for engine combustion simulation (open access)

Sensitivity analysis of large system of chemical kinetic parameters for engine combustion simulation

In this study, the authors applied the state-of-the art sensitivity methods to downselect system parameters from 4000+ to 8, (23000+ -> 4000+ -> 84 -> 8). This analysis procedure paves the way for future works: (1) calibrate the system response using existed experimental observations, and (2) predict future experiment results, using the calibrated system.
Date: April 19, 2012
Creator: Hsieh, H; Sanz-Argent, J; Petitpas, G; Havstad, M & Flowers, D
Object Type: Article
System: The UNT Digital Library
SILICA GEL BEHAVIOR UNDER DIFFERENT EGS CHEMICAL AND THERMAL CONDITIONS: AN EXPERIMENTAL STUDY (open access)

SILICA GEL BEHAVIOR UNDER DIFFERENT EGS CHEMICAL AND THERMAL CONDITIONS: AN EXPERIMENTAL STUDY

Fractures and fracture networks are the principal pathways for migration of water and contaminants in groundwater systems, fluids in enhanced geothermal systems (EGS), oil and gas in petroleum reservoirs, carbon dioxide leakage from geological carbon sequestration, and radioactive and toxic industrial wastes from underground storage repositories. When dealing with EGS fracture networks, there are several major issues to consider, e.g., the minimization of hydraulic short circuits and losses of injected geothermal fluid to the surrounding formation, which in turn maximize heat extraction and economic production. Gel deployments to direct and control fluid flow have been extensively and successfully used in the oil industry for enhanced oil recovery. However, to the best of our knowledge, gels have not been applied to EGS to enhance heat extraction. In-situ gelling systems can either be organic or inorganic. Organic polymer gels are generally not thermostable to the typical temperatures of EGS systems. Inorganic gels, such as colloidal silica gels, however, may be ideal blocking agents for EGS systems if suitable gelation times can be achieved. In the current study, we explore colloidal silica gelation times and rheology as a function of SiO{sub 2} concentration, pH, salt concentration, and temperature, with preliminary results in the …
Date: January 19, 2012
Creator: Hunt, J D; Ezzedine, S M; Bourcier, W & Roberts, S
Object Type: Article
System: The UNT Digital Library
Integrated Detection of Pathogens and Host Biomarkers for Wounds (open access)

Integrated Detection of Pathogens and Host Biomarkers for Wounds

The increasing incidence and complications arising from combat wounds has necessitated a reassessment of methods for effective treatment. Infection, excessive inflammation, and incidence of drug-resistant organisms all contribute toward negative outcomes for afflicted individuals. The organisms and host processes involved in wound progression, however, are incompletely understood. We therefore set out, using our unique technical resources, to construct a profile of combat wounds which did or did not successfully resolve. We employed the Lawrence Livermore Microbial Detection Array and identified a number of nosocomial pathogens present in wound samples. Some of these identities corresponded with bacterial isolates previously cultured, while others were not obtained via standard microbiology. Further, we optimized proteomics protocols for the identification of host biomarkers indicative of various stages in wound progression. In combination with our pathogen data, our biomarker discovery efforts will provide a profile corresponding to wound complications, and will assist significantly in treatment of these complex cases.
Date: March 19, 2012
Creator: Jaing, C
Object Type: Report
System: The UNT Digital Library
Radioactive Waste Conditioning, Immobilisation, And Encapsulation Processes And Technologies: Overview And Advances (Chapter 7) (open access)

Radioactive Waste Conditioning, Immobilisation, And Encapsulation Processes And Technologies: Overview And Advances (Chapter 7)

The main immobilization technologies that are available commercially and have been demonstrated to be viable are cementation, bituminization, and vitrification. Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either alkali borosilicate glass or alkali aluminophosphate glass. The exact compositions of nuclear waste glasses are tailored for easy preparation and melting, avoidance of glass-in-glass phase separation, avoidance of uncontrolled crystallization, and acceptable chemical durability, e.g., leach resistance. Glass has also been used to stabilize a variety of low level wastes (LLW) and mixed (radioactive and hazardous) low level wastes (MLLW) from other sources such as fuel rod cladding/decladding processes, chemical separations, radioactive sources, radioactive mill tailings, contaminated soils, medical research applications, and other commercial processes. The sources of radioactive waste generation are captured in other chapters in this book regarding the individual practices in various countries (legacy wastes, currently generated wastes, and future waste generation). Future waste generation is primarily driven by interest in sources of clean energy and this has led to an increased interest in advanced nuclear power production. The development of advanced wasteforms is a …
Date: October 19, 2012
Creator: Jantzen, Carol M.; Lee, William E. & Ojovan, Michael I.
Object Type: Book
System: The UNT Digital Library
Hemp as an Agricultural Commodity (open access)

Hemp as an Agricultural Commodity

This report provides an overview of Hemp as an Agricultural Commodity. Industrial hemp is a variety of Cannabis sativa and is of the same species of Marijuana. However, hemp is genetically different and distinguished by its use and chemical makeup.
Date: January 19, 2012
Creator: Johnson, Renée
Object Type: Report
System: The UNT Digital Library
Generalized System of Preferences: Background and Renewal Debate (open access)

Generalized System of Preferences: Background and Renewal Debate

This report presents, first, a brief history, economic rationale, and legal background leading to the establishment of the Generalized System of Preferences (GSP). Second, the report presents a discussion of U.S. implementation of the GSP, along with the present debate surrounding its renewal and legislative developments to date. Third, an analysis of the U.S. program's effectiveness and the positions of various stakeholders are presented. Fourth, implications of the expiration of the U.S. program and possible options for Congress are discussed.
Date: April 19, 2012
Creator: Jones, Vivian C.
Object Type: Report
System: The UNT Digital Library
Positron annihilation lifetime spectroscopy of mechanically milled protein fibre powders and their free volume aspects (open access)

Positron annihilation lifetime spectroscopy of mechanically milled protein fibre powders and their free volume aspects

N/A
Date: August 19, 2012
Creator: K., Patil; S., Smith; Sellaiyan, S.; Rajkhowa, R.; Tsuzuki, T.; Lin, T. et al.
Object Type: Article
System: The UNT Digital Library
U.S.-China Military Contacts: Issues for Congress (open access)

U.S.-China Military Contacts: Issues for Congress

This CRS report, updated as warranted, discusses policy issues regarding military-to-military (mil-to-mil) contacts with the People's Republic of China (PRC) and provides a record of major contacts and crises since 1993.
Date: June 19, 2012
Creator: Kan, Shirley A.
Object Type: Report
System: The UNT Digital Library