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Mechanical and charge transport properties of alkanethiol self-assembled monolayers on Au (111) surface: The Role of Molecular Tilt

Description: The relationship between charge transport and mechanical properties of alkanethiol self-assembled monolayers (SAM) on Au(111) films has been investigated using an atomic force microscope with a conductive tip. Molecular tilts induced by the pressure applied by the tip cause stepwise increases in film conductivity. A decay constant {beta} = 0.57 {+-} 0.03 {angstrom}{sup -1} was found for the current passing through the film as a function of tip-substrate separation due to this molecular tilt. Th… more
Date: November 12, 2007
Creator: Mulleregan, Alice; Qi, Yabing; Ratera, Imma; Park, Jeong Y.; Ashby, Paul D.; Quek, Su Ying et al.
Partner: UNT Libraries Government Documents Department
open access

Assessing Recharge and Geological Model Uncertainty at the Climax Mine Area of the Nevada Test Site

Description: Hydrologic analyses are commonly based on a single conceptual-mathematical model. Yet hydrologic environments are open and complex, rendering them prone to multiple interpretations and mathematical descriptions. Considering conceptual model uncertainty is a critical process in hydrologic uncertainty assessment. This study assesses recharge and geologic model uncertainty for the Climax mine area of the Nevada Test Site, Nevada. Five alternative recharge models have been independently developed f… more
Date: November 8, 2007
Creator: Ye, M.; Pohlmann, K.; Chapman, J. & Pohll, G.
Partner: UNT Libraries Government Documents Department
open access

Using RPS Policies to Grow the Solar Market in the United States

Description: The market for photovoltaics in the United States remains small relative to the nation's solar resource potential. Nonetheless, annual grid-connected PV installations have grown from just 4 MW in 2000 to over 100 MW in 2006, fast enough to the catch the attention of the global solar industry. The state of California deserves much of the credit for this growth. The State's historical rebate programs resulted in roughly 75% of the nation's grid-connected PV additions from 2000 through 2006 being … more
Date: November 20, 2007
Creator: Wiser, Ryan H & Wiser, Ryan H.
Partner: UNT Libraries Government Documents Department
open access

The Surface Detector System of the Pierre Auger Observatory

Description: The Pierre Auger Observatory is designed to study cosmic rays with energies greater than 10{sup 19} eV. Two sites are envisaged for the observatory, one in each hemisphere, for complete sky coverage. The southern site of the Auger Observatory, now approaching completion in Mendoza, Argentina, features an array of 1600 water-Cherenkov surface detector stations covering 3000 km{sup 2}, together with 24 fluorescence telescopes to record the air shower cascades produced by these particles. The two … more
Date: November 1, 2007
Creator: Allekotte, I.; Barbosa, A.F.; Bauleo, P.; Bonifazi, C.; Civit, B.; Escobar, C.O. et al.
Partner: UNT Libraries Government Documents Department
open access

Study of the Tau- to Pi- Pi+ Pi- Pi0 Nu/Tau And Tau- to Pi- Pi- Pi+ Eta Nu/Tau Decays Using the BaBar Detector

Description: The {tau}{sup -} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}} and {tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{eta}{nu}{sub {tau}} decays have been studied with the BABAR detector. Preliminary branching fractions on the two modes are presented. The {tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{eta}{nu}{sub {tau}} mode is found to have a large contribution from the {tau}{sup -} {yields} {omega}{pi}{sup -}{nu}{sub {tau}} decay. The {tau}{sup -} {yields} {pi}{sup … more
Date: November 14, 2007
Creator: Sobie, Randall
Partner: UNT Libraries Government Documents Department
open access

COMPARISONS OF CRYSTALLINE SILICOTITANATE AND RESORCINOL FORMALDEHYDE MEDIA FOR CESIUM REMOVAL BY IN-TANK COLUMN PROCESSING

Description: Chemical and thermal performance of crystalline silicotitanate (CST) and resorcinol-formaldehyde (RF) ion exchange media were predicted for column configurations designed for installation in high level waste tanks and intended for cesium removal from radioactive waste supernates. Modeling predictions for the processing of a known Savannah River Site tank waste composition were generated. In a two column configuration under presumed nominal operating conditions (432 gallon packed bed, 10 gpm liq… more
Date: November 7, 2007
Creator: King, W; Frank02 Smith, F; Si Lee, S & Daniel McCabe, D
Partner: UNT Libraries Government Documents Department
open access

Measurement of correlated b-bbar production in p-pbar collisions at s**(1/2) = 1960 GeV

Description: We present a measurement of the correlated b{bar b} production cross section. The data used in this analysis were taken with the upgraded CDF detector (CDF II) at the Fermilab Tevatron collider, and correspond to an integrated luminosity of 742 pb{sup -1}. We utilize muon pairs with invariant mass 5 {le} m{sub {mu}{mu}} {le} 80 GeV/c{sup 2} produced by b{bar b} double semileptonic decays. For muons with p{sub T} {ge} 3 GeV/c and |{eta}| {le} 0.7, that are produced by b and {bar b} quarks with p… more
Date: November 1, 2007
Creator: Aaltonen, T.; Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M. G. et al.
Partner: UNT Libraries Government Documents Department
open access

LC scintillator-based muon detector tail-catcher R&D

Description: Preliminary analysis of test beam data from strip scintillator planes read-out with multi-anode PMTs (MAPMTs) is presented along with a description of the independent systematic measurements of relative response for all channels of several MAPMTs used in the tests. Test beam measurements for the response of a scintillator strip, read out with Si photo-sensors, is also described.
Date: November 1, 2007
Creator: Abrams, R.; Blazey, G.; Driutti, A.; Dychkant, A.; Fisk, H.E.; Gutierrez, A. et al.
Partner: UNT Libraries Government Documents Department
open access

Sharp Reduction of the Secondary Electron Emission Yield from Grooved Surfaces

Description: The effect of an artificially-enhanced rough surface on the secondary electron emission yield (SEY) was investigated both theoretically and experimentally. Analytical studies on triangular and rectangular grooved surfaces show the connection between the characteristic parameters of a given geometry to the SEY reduction. The effect of a strong magnetic field is also discussed. SEY of grooved samples have been measured and the results agree with Monte-Carlo simulations.
Date: November 28, 2007
Creator: Pivi, M. T. F.; King, F. K.; Kirby, R. E.; Ruabenheimer, T. O.; Stupakov, G. & Le Pimpec, F.
Partner: UNT Libraries Government Documents Department
open access

TREATABILITY TEST FOR REMOVING TECHNETIUM-99 FROM 200-ZP-1 GROUNDWATER HANFORD SITE

Description: The 200-ZP-1 Groundwater Operable Unit (OU) is one of two groundwater OUs located within the 200 West groundwater aggregate area of the Hanford Site. The primary risk-driving contaminants within the 200-ZP-1 OU include carbon tetrachloride and technetium-99 (Tc-99). A pump-and-treat system for this OU was initially installed in 1995 to control the 0.002 kg/m{sup 3} (2000 {micro}g/L) contour of the carbon tetrachloride plume. Carbon tetrachloride is removed from groundwater with the assistance o… more
Date: November 29, 2007
Creator: SW, PETERSEN; AC, TORTOSO; WS, ELLIOTT & ME, BYRNES
Partner: UNT Libraries Government Documents Department
open access

The Emma Commissioning Procedure

Description: The author begins with a brief review of the goals of the EMMA experiment. He then describe two stages of EMMA commissioning. The first stage is simply to get the beam to circulate a full turn in the ring, and is done only once during the course of the experiment. The second stage will be repeated several times, at least once for each lattice configuration, and involves two parts: setting the required values for the machine parameters, and determining the tunes and time of flight as a function … more
Date: November 5, 2007
Creator: Berg, J. S.
Partner: UNT Libraries Government Documents Department
open access

HESS J1023-575: Non-Thermal Particle Acceleration Associated With the Young Stellar Cluster Westerlund 2

Description: The results from H.E.S.S. observations towards Westerlund 2 are presented. The detection of very-high-energy gamma-ray emission towards the young stellar cluster Westerlund 2 in the HII complex RCW49 by H.E.S.S. provides ample evidence that particle acceleration to extreme energies is associated with this region. A variety of possible emission scenarios is mentioned, ranging from high-energy gamma-ray production in the colliding wind zone of the massive Wolf-Rayet binary WR 20a, collective wind… more
Date: November 14, 2007
Creator: Reimer, O.; /Stanford U., HEPL /KIPAC, Menlo Park; Hinton, J.; U., /Leeds; Hofmann, W.; Hoppe, S. et al.
Partner: UNT Libraries Government Documents Department
open access

ELECTRICAL SAFETY IMPROVEMENT PROJECT A COMPLEX WIDE TEAMING INITIATIVE

Description: This paper describes the results of a year-long project, sponsored by the Energy Facility Contractors Group (EFCOG) and designed to improve overall electrical safety performance throughout Department of Energy (DOE)-owned sites and laboratories. As evidenced by focused metrics, the Project was successful primarily due to the joint commitment of contractor and DOE electrical safety experts, as well as significant support from DOE and contractor senior management. The effort was managed by an ass… more
Date: November 26, 2007
Creator: BJ, GRAY
Partner: UNT Libraries Government Documents Department
open access

Verifying the Cosmological Utility of Type Ia Supernovae:Implications of a Dispersion in the Ultraviolet Spectra

Description: We analyze the mean rest-frame ultraviolet (UV) spectrum ofType Ia Supernovae(SNe) and its dispersion using high signal-to-noiseKeck-I/LRIS-B spectroscopyfor a sample of 36 events at intermediateredshift (z=0.5) discoveredby the Canada-France-Hawaii TelescopeSupernova Legacy Survey (SNLS). Weintroduce a new method for removinghost galaxy contamination in our spectra,exploiting the comprehensivephotometric coverage of the SNLS SNe and theirhost galaxies, therebyproviding the first quantitative v… more
Date: November 2, 2007
Creator: Ellis, R. S.; Sullivan, M.; Nugent, P. E.; Howell, D. A.; Gal-Yam, A.; Astier, P. et al.
Partner: UNT Libraries Government Documents Department
open access

GENERATING THE RIGHT PCB DATA DETERMINATION OF AROCLORS VERSUS PCB CONGENERS

Description: Polychlorinated biphenyls (PCBs) are a major environmental concern due to their ubiquity and tendency to bio-accumulate. as well as their persistence and toxicity. As the cleanup of waste and contaminated soil progresses at U.S. Department of Energy (DOE) sites, the costs for accurate PCB data are increasing. PCBs are actually a broad name for a group of 209 individual compounds known as congeners. PCBs were originally produced in the United States as specific mixtures of congeners known as Aro… more
Date: November 21, 2007
Creator: CT, NARQUIS & AL, PRIGNANO
Partner: UNT Libraries Government Documents Department
open access

Analysis of the SL-1 Accident Using RELAPS5-3D

Description: On January 3, 1961, at the National Reactor Testing Station, in Idaho Falls, Idaho, the Stationary Low Power Reactor No. 1 (SL-1) experienced a major nuclear excursion, killing three people, and destroying the reactor core. The SL-1 reactor, a 3 MW{sub t} boiling water reactor, was shut down and undergoing routine maintenance work at the time. This paper presents an analysis of the SL-1 reactor excursion using the RELAP5-3D thermal-hydraulic and nuclear analysis code, with the intent of simulat… more
Date: November 8, 2007
Creator: Francisco, A.D. and Tomlinson, E. T.
Partner: UNT Libraries Government Documents Department
open access

Optimal Heat Collection Element Shapes for Parabolic Trough Concentrators

Description: For nearly 150 years, the cross section of the heat collection tubes used at the focus of parabolic trough solar concentrators has been circular. This type of tube is obviously simple and easily fabricated, but it is not optimal. It is shown in this article that the optimal shape, assuming a perfect parabolic figure for the concentrating mirror, is instead oblong, and is approximately given by a pair of facing parabolic segments.
Date: November 15, 2007
Creator: Bennett, C
Partner: UNT Libraries Government Documents Department
open access

Communication Requirements and Interconnect Optimization forHigh-End Scientific Applications

Description: The path towards realizing peta-scale computing isincreasingly dependent on building supercomputers with unprecedentednumbers of processors. To prevent the interconnect from dominating theoverall cost of these ultra-scale systems, there is a critical need forhigh-performance network solutions whose costs scale linearly with systemsize. This work makes several unique contributions towards attaining thatgoal. First, we conduct one of the broadest studies to date of high-endapplication communicati… more
Date: November 12, 2007
Creator: Kamil, Shoaib; Oliker, Leonid; Pinar, Ali & Shalf, John
Partner: UNT Libraries Government Documents Department
open access

SUSY Les Houches Accord 2

Description: The Supersymmetry Les Houches Accord (SLHA) [1] provides a universal set of conventions for conveying spectral and decay information for supersymmetry analysis problems in high energy physics. Here, we propose extensions of the conventions of the first SLHA to include various generalizations: the minimal supersymmetric standard model with violation of CP, R-parity, and flavor, as well as the simplest next-to-minimal model.
Date: November 8, 2007
Creator: Allanach, B.; Balazs, C.; Belanger, G.; Bernhardt, M.; Boudjema, F.; Choudhury, D. et al.
Partner: UNT Libraries Government Documents Department
open access

A HAMILTONIAN FORMULATION FOR SPIRAL-SECTOR ACCELERATORS.

Description: I develop a formulation for Hamiltonian dynamics in an accelerator with magnets whose edges follow a spiral. I demonstrate using this Hamiltonian that a spiral FFAG can be made perfectly 'scaling'. I examine the effect of tilting an RF cavity with respect a radial line from the center of the machine, potentially with a different angle than the spiral of the magnets.
Date: November 5, 2007
Creator: Berg, J. S.
Partner: UNT Libraries Government Documents Department
open access

Task Group 7B: Cellular and Molecular Mechanisms of Biological Aging: The Roles of Nature, Nurture and Chance in the Maintenance of Human Healthspan

Description: The degree to which an individual organism maintains healthspan and lifespan is a function of complex interactions between genetic inheritance ('nature'), environment, including cultural inheritance (nurture) and stochastic events ('luck' or 'chance'). This task group will focus upon the role of chance because it is so poorly understood and because it appears to be of major importance in the determination of individual variations in healthspan and lifespan within species. The major factor deter… more
Date: November 14, 2007
Creator: Weier, Heinz-Ulrich; Arya, Suresh; Grant, Christine; Miller, Linda; Ono, Santa Jeremy; Patil, Chris et al.
Partner: UNT Libraries Government Documents Department
open access

REVIEW OF EXPERIMENTAL CAPABILITIES AND HYDRODYNAMIC DATA FOR VALIDATION OF CFD-BASED PREDICTIONS FOR SLURRY BUBBLE COLUMN REACTORS

Description: The purpose of this paper is to document the review of several open-literature sources of both experimental capabilities and published hydrodynamic data to aid in the validation of a Computational Fluid Dynamics (CFD) based model of a slurry bubble column (SBC). The review included searching the Web of Science, ISI Proceedings, and Inspec databases, internet searches as well as other open literature sources. The goal of this study was to identify available experimental facilities and relevant d… more
Date: November 1, 2007
Creator: Guillen, Donna Post; Wendt, Daniel S.; Antal, Steven P. & Podowski, Michael Z.
Partner: UNT Libraries Government Documents Department
open access

Non-inclusive searches for squarks and gluinos at the Tevatron

Description: Recent results from the CDF and D0 Collaborations on searches for squarks and gluinos at the Run II of the Fermilab Tevatron collider are presented. This review covers searches for final states involving specific mass hierarchies. The analyzed datasets correspond to an integrated luminosity of 300-1000 pb{sup -1} collected from proton anti-proton collisions at a center-of-mass energy of 1.96 TeV. No significant deviations from the Standard Model expectations are observed and limits on parameter… more
Date: November 1, 2007
Creator: Biscarat, Catherine & /Lyon, IPN
Partner: UNT Libraries Government Documents Department
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