An FMEA Analysis for Photovoltaic Systems: Assessing Different System Configurations to Support Reliability Studies - Introduction to PRA Analysis for PV Systems (open access)
ZDC Effective Cross Section for Uranium-Uranium Collisions in Run 12 (open access)

ZDC Effective Cross Section for Uranium-Uranium Collisions in Run 12

N/A
Date: December 9, 2013
Creator: A., Drees
Object Type: Report
System: The UNT Digital Library
CONFIRMATORY SURVEY RESULTS FOR PORTIONS OF THE ABB COMBUSTION ENGINEERING SITE IN WINDSOR, CONNECTICUT DURING THE FALL OF 2011 (open access)

CONFIRMATORY SURVEY RESULTS FOR PORTIONS OF THE ABB COMBUSTION ENGINEERING SITE IN WINDSOR, CONNECTICUT DURING THE FALL OF 2011

From the mid-1950s until mid-2000, the Combustion Engineering, Inc. (CE) site in Windsor, Connecticut (Figure A-1) was involved in the research, development, engineering, production, and servicing of nuclear fuels, systems, and services. The site is currently undergoing decommissioning that will lead to license termination and unrestricted release in accordance with the requirements of the License Termination Rule in 10 CFR Part 20, Subpart E. Asea Brown Boveri Incorporated (ABB) has been decommissioning the CE site since 2001.
Date: December 9, 2011
Creator: Adams, Wade C.
Object Type: Report
System: The UNT Digital Library
What Limits the Gap in a Flat Dechirper for an X-ray FEL (open access)

What Limits the Gap in a Flat Dechirper for an X-ray FEL

None
Date: December 9, 2013
Creator: Bane, K. L. F. & Stupakov, G.
Object Type: Report
System: The UNT Digital Library
Lessons Learned From a Site-Wide Power Outage (open access)

Lessons Learned From a Site-Wide Power Outage

None
Date: December 9, 2011
Creator: Bartelt, John
Object Type: Article
System: The UNT Digital Library
Improved Characterization of Transmitted Wavefront Error on CADB Epoxy-Free Bonded Solid State Laser Materials (open access)

Improved Characterization of Transmitted Wavefront Error on CADB Epoxy-Free Bonded Solid State Laser Materials

Current state-of-the-art and next generation laser systems - such as those used in the NIF and LIFE experiments at LLNL - depend on ever larger optical elements. The need for wide aperture optics that are tolerant of high power has placed many demands on material growers for such diverse materials as crystalline sapphire, quartz, and laser host materials. For such materials, it is either prohibitively expensive or even physically impossible to fabricate monolithic pieces with the required size. In these cases, it is preferable to optically bond two or more elements together with a technique such as Chemically Activated Direct Bonding (CADB{copyright}). CADB is an epoxy-free bonding method that produces bulk-strength bonded samples with negligible optical loss and excellent environmental robustness. The authors have demonstrated CADB for a variety of different laser glasses and crystals. For this project, they will bond quartz samples together to determine the suitability of the resulting assemblies for large aperture high power laser optics. The assemblies will be evaluated in terms of their transmitted wavefront error, and other optical properties.
Date: December 9, 2010
Creator: Bayramian, A.
Object Type: Article
System: The UNT Digital Library
Constructing Amplitudes from Their Soft Limits (open access)

Constructing Amplitudes from Their Soft Limits

The existence of universal soft limits for gauge-theory and gravity amplitudes has been known for a long time. The properties of the soft limits have been exploited in numerous ways; in particular for relating an n-point amplitude to an (n-1)-point amplitude by removing a soft particle. Recently, a procedure called inverse soft was developed by which 'soft' particles can be systematically added to an amplitude to construct a higher-point amplitude for generic kinematics. We review this procedure and relate it to Britto-Cachazo-Feng-Witten recursion. We show that all tree-level amplitudes in gauge theory and gravity up through seven points can be constructed in this way, as well as certain classes of NMHV gauge-theory amplitudes with any number of external legs. This provides us with a systematic procedure for constructing amplitudes solely from their soft limits.
Date: December 9, 2011
Creator: Boucher-Veronneau, Camille & Larkoski, Andrew J.
Object Type: Article
System: The UNT Digital Library
Theory of Microwave Instability and Coherent Synchrotron Radiation in Electron Storage Rings (open access)

Theory of Microwave Instability and Coherent Synchrotron Radiation in Electron Storage Rings

Bursting of coherent synchrotron radiation has been observed and in fact used to generate THz radiation in many electron storage rings. In order to understand and control the bursting, we return to the study of the microwave instability. In this paper, we will report on the theoretical understanding, including recent developments, of the microwave instability in electron storage rings. The historical progress of the theories will be surveyed, starting from the dispersion relation of coasting beams, to the work of Sacherer on a bunched beam, and ending with the Oide and Yokoya method of discretization. This theoretical survey will be supplemented with key experimental results over the years. Finally, we will describe the recent theoretical development of utilizing the Laguerre polynomials in the presence of potential-well distortion. This self-consistent method will be applied to study the microwave instability driven the impedances due to the coherent synchrotron radiation. Over the past quarter century, there has been steady progress toward smaller transverse emittances in electron storage rings used for synchrotron light sources, from tens of nm decades ago to the nm range recently. In contrast, there is not much progress made in the longitudinal plane. For an electron bunch in a typical …
Date: December 9, 2011
Creator: Cai, Y.
Object Type: Article
System: The UNT Digital Library
An Exploration of Catalytic Chemistry on Au/Ni(111) (open access)

An Exploration of Catalytic Chemistry on Au/Ni(111)

This project explored the catalytic oxidation chemistry that can be effected on a Au/Ni(111) surface alloy. A Au/Ni(111) surface alloy is a Ni(111) surface on which less than 60% of the Ni atoms are replaced at random positions by Au atoms. The alloy is produced by vapor deposition of a small amount of Au onto Ni single crystals. The Au atoms do not result in an epitaxial Au overlayer or in the condensation of the Au into droplets. Instead, Au atoms displace and then replace Ni atoms on a Ni(111) surface, even though Au is immiscible in bulk Ni. The two dimensional structure of the clean Ni surface is preserved. This alloy is found to stabilize an adsorbed peroxo-like O2 species that is shown to be the critical reactant in the low temperature catalytic oxidation of CO and that is suspected to be the critical reactant in other oxidation reactions. This investigation revealed a new, practically important catalyst for CO oxidation that has since been patented.
Date: December 9, 2011
Creator: Ceyer, Sylvia T.
Object Type: Report
System: The UNT Digital Library
Assessment of Technologies Used to Characterize Wildlife Populations in the Offshore Environment (open access)

Assessment of Technologies Used to Characterize Wildlife Populations in the Offshore Environment

Wind energy development in the offshore environment can have both direct and indirect effects on wildlife, yet little is known about most species that use near-shore and offshore waters due in part to the difficulty involved in studying animals in remote, challenging environments. Traditional methods to characterize offshore wildlife populations include shipboard observations. Technological advances have provided researches with an array of technologies to gather information about fauna from afar. This report describes the use and application of radar, thermal and optical imagery, and acoustic detection technologies for monitoring birds, bats, and marine mammals in offshore environments.
Date: December 9, 2011
Creator: Duberstein, Corey A.; Tagestad, Jerry D. & Larson, Kyle B.
Object Type: Report
System: The UNT Digital Library
CORROSION TESTING IN SIMULATED TANK SOLUTIONS (open access)

CORROSION TESTING IN SIMULATED TANK SOLUTIONS

Three simulated waste solutions representing wastes from tanks SY-102 (high nitrate, modified to exceed guidance limits), AN-107, and AY-102 were supplied by PNNL. Out of the three solutions tested, both optical and electrochemical results show that carbon steel samples corroded much faster in SY-102 (high nitrate) than in the other two solutions with lower ratios of nitrate to nitrite. The effect of the surface preparation was not as strong as the effect of solution chemistry. In areas with pristine mill-scale surface, no corrosion occurred even in the SY-102 (high nitrate) solution, however, corrosion occurred in the areas where the mill-scale was damaged or flaked off due to machining. Localized corrosion in the form of pitting in the vapor space of tank walls is an ongoing challenge to overcome in maintaining the structural integrity of the liquid waste tanks at the Savannah River and Hanford Sites. It has been shown that the liquid waste condensate chemistry influences the amount of corrosion that occurs along the walls of the storage tanks. To minimize pitting corrosion, an effort is underway to gain an understanding of the pitting response in various simulated waste solutions. Electrochemical testing has been used as an accelerated tool in …
Date: December 9, 2010
Creator: Hoffman, E.
Object Type: Report
System: The UNT Digital Library
PROBABILITY BASED CORROSION CONTROL FOR LIQUID WASTE TANKS - PART III (open access)

PROBABILITY BASED CORROSION CONTROL FOR LIQUID WASTE TANKS - PART III

The liquid waste chemistry control program is designed to reduce the pitting corrosion occurrence on tank walls. The chemistry control program has been implemented, in part, by applying engineering judgment safety factors to experimental data. However, the simple application of a general safety factor can result in use of excessive corrosion inhibiting agents. The required use of excess corrosion inhibitors can be costly for tank maintenance, waste processing, and in future tank closure. It is proposed that a probability-based approach can be used to quantify the risk associated with the chemistry control program. This approach can lead to the application of tank-specific chemistry control programs reducing overall costs associated with overly conservative use of inhibitor. Furthermore, when using nitrite as an inhibitor, the current chemistry control program is based on a linear model of increased aggressive species requiring increased protective species. This linear model was primarily supported by experimental data obtained from dilute solutions with nitrate concentrations less than 0.6 M, but is used to produce the current chemistry control program up to 1.0 M nitrate. Therefore, in the nitrate space between 0.6 and 1.0 M, the current control limit is based on assumptions that the linear model developed from …
Date: December 9, 2010
Creator: Hoffman, E. & Edwards, T.
Object Type: Report
System: The UNT Digital Library
PROBABILITY BASED CORROSION CONTROL FOR WASTE TANKS - PART II (open access)

PROBABILITY BASED CORROSION CONTROL FOR WASTE TANKS - PART II

As part of an ongoing study to evaluate the discontinuity in the corrosion controls at the SRS tank farm, a study was conducted this year to assess the minimum concentrations below 1 molar nitrate, see Figure 1. Current controls on the tank farm solution chemistry are in place to prevent the initiation and propagation of pitting and stress corrosion cracking in the primary steel waste tanks. The controls are based upon a series of experiments performed with simulated solutions on materials used for construction of the tanks, namely ASTM A537 carbon steel (A537). During FY09, an experimental program was undertaken to investigate the risk associated with reducing the minimum molar nitrite concentration required to confidently inhibit pitting in dilute solutions (i.e., less than 1 molar nitrate). The experimental results and conclusions herein provide a statistical basis to quantify the probability of pitting for the tank wall exposed to various solutions with dilute concentrations of nitrate and nitrite. Understanding the probability for pitting will allow the facility to make tank-specific risk-based decisions for chemistry control. Based on previous electrochemical testing, a statistical test matrix was developed to refine and solidify the application of the statistical mixture/amount model to corrosion of A537 …
Date: December 9, 2010
Creator: Hoffman, E. & Edwards, T.
Object Type: Report
System: The UNT Digital Library
Ag BL Description for General Atomics (open access)

Ag BL Description for General Atomics

None
Date: December 9, 2013
Creator: Huntington, C.
Object Type: Report
System: The UNT Digital Library
Time-Integrated Searches for Point-like Sources of Neutrinos with the 40-String IceCube Detector (open access)

Time-Integrated Searches for Point-like Sources of Neutrinos with the 40-String IceCube Detector

None
Date: December 9, 2010
Creator: IceCube & etal, Abbasi, R,
Object Type: Article
System: The UNT Digital Library
Precise Predictions for Z + 4 Jets at Hadron Colliders (open access)

Precise Predictions for Z + 4 Jets at Hadron Colliders

We present the cross section for production of a Z boson in association with four jets at the Large Hadron Collider, at next-to-leading order in the QCD coupling. When the Z decays to neutrinos, this process is a key irreducible background to many searches for new physics. Its computation has been made feasible through the development of the on-shell approach to perturbative quantum field theory. We present the total cross section for pp collisions at {radical}s = 7 TeV, after folding in the decay of the Z boson, or virtual photon, to a charged-lepton pair. We also provide distributions of the transverse momenta of the four jets, and we compare cross sections and distributions to the corresponding ones for the production of a W boson with accompanying jets.
Date: December 9, 2011
Creator: Ita, H.; Bern, Z.; Dixon, L.J.; Cordero, F.Febres; Kosower, D.A. & Maitre, D.
Object Type: Article
System: The UNT Digital Library
Deciphering the Electron Transport Pathway for Graphene Oxide Reduction by Shewanella oneidensis MR-1 (open access)

Deciphering the Electron Transport Pathway for Graphene Oxide Reduction by Shewanella oneidensis MR-1

None
Date: December 9, 2010
Creator: Jiao, Y.; Qian, F.; Li, Y.; Wang, G. M.; Saltikov, C. & Granick, J.
Object Type: Article
System: The UNT Digital Library
Transverse Emittance Reduction with Tapered Foil (open access)

Transverse Emittance Reduction with Tapered Foil

The idea of reducing transverse emittance with tapered energy-loss foil is proposed by J.M. Peterson in 1980s and recently by B. Carlsten. In this paper, we present the physical model of tapered energy-loss foil and analyze the emittance reduction using the concept of eigen emittance. The study shows that, to reduce transverse emittance, one should collimate at least 4% of particles which has either much low energy or large transverse divergence. The multiple coulomb scattering is not trivial, leading to a limited emittance reduction ratio. Small transverse emittances are of essential importance for the accelerator facilities generating free electron lasers, especially in hard X-ray region. The idea of reducing transverse emittance with tapered energy-loss foil is recently proposed by B. Carlsten [1], and can be traced back to J.M. Peterson's work in 1980s [2]. Peterson illustrated that a transverse energy gradient can be produced with a tapered energy-loss foil which in turn leads to transverse emittance reduction, and also analyzed the emittance growth from the associated multiple coulomb scattering. However, what Peterson proposed was rather a conceptual than a practical design. In this paper, we build a more complete physical model of the tapered foil based on Ref. [2], including …
Date: December 9, 2011
Creator: Jiao, Yi; Chao, Alex & Cai, Yunhai
Object Type: Article
System: The UNT Digital Library
Generation of non-axisymmetric scrape-off layer perturbations for controlling tokamak edge plasma profiles and stability (open access)

Generation of non-axisymmetric scrape-off layer perturbations for controlling tokamak edge plasma profiles and stability

None
Date: December 9, 2011
Creator: Joseph, I.; Cohen, R. H.; Rognlien, T. D. & Ryutov, D. D.
Object Type: Article
System: The UNT Digital Library
Study of di-pion Bottomonium Transitions and Search for the h_b(1P) State (open access)

Study of di-pion Bottomonium Transitions and Search for the h_b(1P) State

We study inclusive di-pion decays using a sample of 108 x 10{sup 6} {Upsilon}(3S) events recorded with the BABAR detector. We search for the decay mode {Upsilon}(3S) {yields} {pi}{sup +}{pi}{sup -}h{sub b} (1P) and find no evidence for the bottomonium spin-singlet state h{sub b}(1P) in the invariant mass distribution recoiling against the {pi}{sup +}{pi}{sup -} system. Assuming the h{sub b}(1P) mass to be 9.900 GeV/c{sup 2}, we measure the upper limit on the branching fraction {Beta}[{Upsilon}(3S) {yields} {pi}{sup +}{pi}{sup -}h{sub b}(1P)] < 1.2 x 10{sup -4}, at 90% confidence level. We also investigate the {chi}{sub bJ}(2P) {yields} {pi}{sup +}{pi}{sup -} {chi}{sub bJ}(1P), {Upsilon}(3S) {yields} {pi}{sup +}{pi}{sup -}{Upsilon}(2S), and {Upsilon}(2S) {yields} {pi}{sup +}{pi}{sup -}{Upsilon}(1S) di-pion transitions and present an improved measurement of the branching fraction of the {Upsilon}(3S) {yields} {pi}{sup +}{pi}{sup -}{Upsilon}(2S) decay and of the {Upsilon}(3S) - {Upsilon}(2S) mass difference.
Date: December 9, 2011
Creator: Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M. et al.
Object Type: Article
System: The UNT Digital Library
Laboratory Calibration of Density-Dependent Lines in the EUV and Soft X-Ray Regions (open access)

Laboratory Calibration of Density-Dependent Lines in the EUV and Soft X-Ray Regions

We analyzed spectral data of Fe XXII and Ar XIV from laboratory sources in which the electron density varies by several orders of magnitude to help benchmark density-sensitive emission lines useful for astrophysics and to test the atomic models underlying the diagnostic line ratios. We found excellent agreement for Fe XXII, but poorer agreement for Ar XIV. A number of astrophysically important emission lines are sensitive to electron density in the EUV and soft X-ray regions. Lines from Fe XXII, for example, have been used in recent years as diagnostics of stellar coronae, such as the active variable AB Dor, Capella, and EX Hya (Sanz-Forcada et al. 2003, Mewe et al. 2001, Mauche et al. 2003). Here we report spectral data of Fe XXII and Ar XIV from laboratory sources in which the electron density is known from either K-shell density diagnostics (for electron beam ion traps) or from non-spectroscopic means (tokamaks), ranging from 5 x 10{sup 10} cm{sup -3} to 5 x 10{sup 14} cm{sup -3}. These measurements were used to test the atomic data underlying the density diagnostic line ratios, complementing earlier work (Chen et al. 2004).
Date: December 9, 2010
Creator: Lepson, J K; Beiersdorfer, P; Gu, M F & Desai, P
Object Type: Article
System: The UNT Digital Library
Solid State NMR Investigations of Chain Dynamics and Network Order in Model Poly(dimethylsiloxane) Elastomers (open access)

Solid State NMR Investigations of Chain Dynamics and Network Order in Model Poly(dimethylsiloxane) Elastomers

This work is at a relatively early stage, however it has been demonstrated that we can reliably probe basic network architectures using the MQ-NMR technique. The initial results are in good agreement with what is known from standard network theory and will serve as a basis for the study of progressively increasing structural complexity in Siloxane network systems.
Date: December 9, 2010
Creator: Lewicki, J P; Mayer, B P; Wilson, T S; Chinn, S C & Maxwell, R S
Object Type: Article
System: The UNT Digital Library
Computational Mechanics Research and Support for Aerodynamics and Hydraulics at TFHRC Year 1 Quarter 4 Progress Report. (open access)

Computational Mechanics Research and Support for Aerodynamics and Hydraulics at TFHRC Year 1 Quarter 4 Progress Report.

The computational fluid dynamics (CFD) and computational structural mechanics (CSM) focus areas at Argonne's Transportation Research and Analysis Computing Center (TRACC) initiated a project to support and compliment the experimental programs at the Turner-Fairbank Highway Research Center (TFHRC) with high performance computing based analysis capabilities in August 2010. The project was established with a new interagency agreement between the Department of Energy and the Department of Transportation to provide collaborative research, development, and benchmarking of advanced three-dimensional computational mechanics analysis methods to the aerodynamics and hydraulics laboratories at TFHRC for a period of five years, beginning in October 2010. The analysis methods employ well-benchmarked and supported commercial computational mechanics software. Computational mechanics encompasses the areas of Computational Fluid Dynamics (CFD), Computational Wind Engineering (CWE), Computational Structural Mechanics (CSM), and Computational Multiphysics Mechanics (CMM) applied in Fluid-Structure Interaction (FSI) problems. The major areas of focus of the project are wind and water effects on bridges - superstructure, deck, cables, and substructure (including soil), primarily during storms and flood events - and the risks that these loads pose to structural failure. For flood events at bridges, another major focus of the work is assessment of the risk to bridges caused by scour …
Date: December 9, 2011
Creator: Lottes, S.A.; Kulak, R.F. & Bojanowski, C.
Object Type: Report
System: The UNT Digital Library
Main Injector Particle Production Experiment (MIPP) at Fermilab (open access)

Main Injector Particle Production Experiment (MIPP) at Fermilab

The Main Injector Particle Production Experiment at Fermilab uses particle beams of charged pions, kaons, proton and anti-proton with beam momenta of 5 to 90 GeV/c and thin targets spanning the periodic table from (liquid) hydrogen to uranium to measure particle production cross sections in a full acceptance spectrometer with charged particle identification for particles from 0.1 to 120 GeV/c using Time Projection Chamber, Time of Flight, multicell Cherenkov, and Ring Imaging Cherenkov detectors and Calorimeter for neutrons. Particle production using 120 GeV/c protons from Main Injector on the MINOS target was also measured. We describe the physics motivation to perform such cross section measurements and highlight the impact of hadronic interaction data on neutrino physics. Recent results on forward neutron cross sections and analysis of MINOS target data are also presented.
Date: December 9, 2010
Creator: Mahajan, Sonam
Object Type: Article
System: The UNT Digital Library