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Electron Cloud in the Wigglers of the Positron Damping Ring of the International Linear Collider

Description: The ILC positron damping ring comprises hundreds of meters of wiggler sections, where many more photons than in the arcs are emitted, and with the smallest beampipe aperture of the ring. A significant electron-cloud density can therefore be accumulated via photo-emission and via beam-induced multipacting. In field-free regions the electron-cloud build up may be suppressed by adding weak solenoid fields, but the electron cloud remaining in the wigglers as well as in the arc dipole magnets can st… more
Date: July 6, 2007
Creator: Wang, L.
Item Type: Refine your search to only Article
open access

Electron Dynamics of Silicon Surface States: Second-Harmonic HoleBurning on Si(111)7x7

Description: The ultrafast dynamics of electronic excitations of the surface dangling bond states of Si(111) 7 x 7 has been investigated by second harmonic generation as a probe of transient spectral hole burning. Spectral holes induced by a 100 fs pump at {approx_equal} 1.5 eV and their decay are interpreted in terms of electronic dephasing times as short as 15 fs. This fast time scale together with the strong excitation-induced dephasing observed is interpreted in terms of carrier-carrier scattering. In a… more
Date: June 6, 2005
Creator: McGuire, John A.; Raschke, Markus B. & Shen, Yuen-Ron
Item Type: Refine your search to only Article
open access

Electron Energy Distribution in Hotspots of Cygnus A:Filling the Gap with Spitzer Space Telescope

Description: Here we present Spitzer Space Telescope imaging of Cyg A with the Infrared Array Camera at 4.5 {micro}m and 8.0 {micro}m, resulting in the detection of the high-energy tails or cut-offs in the synchrotron spectra for all four hotspots of this archetype radio galaxy. When combined with the other data collected (and re-analyzed) from the literature, our observations allow for detailed modeling of the broad-band (radio-to-X-ray) emission for the brightest spots A and D. We confirm that the X-ray f… more
Date: March 6, 2007
Creator: Stawarz, L.; Cheung, C.C.; Harris, D.E. & Ostrowski, M.
Item Type: Refine your search to only Article
open access

Electronic and Sturctural Transitions in Dense Liquid Sodium

Description: At ambient conditions, the light alkali metals are free-electron like crystals with a highly symmetric structure. However, they were shown recently to exhibit unexpected complexity under pressure. It was predicted from theory and later confirmed by experiment that Li and Na undergo a sequence of symmetry breaking transitions driven by a Peierls mechanism. Most recently, measurements of the Na melting curve revealed an unprecedented and still unexplained drop in the melting temperature from 1000… more
Date: August 6, 2007
Creator: Raty, J Y; Schwegler, E R & Bonev, S A
Item Type: Refine your search to only Report
open access

Electronic Banking: Enhancing Federal Oversight of Internet Banking Activities

Description: A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed federal oversight of depository institutions' Internet banking activities, focusing on: (1) the risks posed by Internet banking and the extent of any industrywide Internet banking-related problems; (2) the methods used by regulators to track depository institutions' plans to provide Internet banking services; (3) how regulators examined Internet banking activit… more
Date: July 6, 1999
Creator: United States. General Accounting Office.
Item Type: Refine your search to only Report
open access

Electronic Government: Smart Card Usage is Advancing Among Federal Agencies, Including the Department of Veterans Affairs

Description: Testimony issued by the Government Accountability Office with an abstract that begins "The federal government is interested in the use of smart cards--credit card-like devices that use integrated circuit chips to store and process data--for improving the security of its many physical and information assets. Besides providing better authentication of the identities of people accessing buildings and computer systems, smart cards offer a number of other potential benefits and uses, such as creatin… more
Date: October 6, 2004
Creator: United States. Government Accountability Office.
Item Type: Refine your search to only Text
open access

Electronic Health Record Programs: Participation Has Increased, but Action Needed to Achieve Goals, Including Improved Quality of Care

Description: A letter report issued by the Government Accountability Office with an abstract that begins "Based on the number of providers awarded incentive payments, participation in the Department of Health and Human Services' (HHS) Medicare and Medicaid Electronic Health Record (EHR) programs increased substantially from their first year in 2011 to 2012. For hospitals, participation increased from 45 percent of those eligible for 2011 to 64 percent of those eligible for 2012. For professionals, such as p… more
Date: March 6, 2014
Creator: United States. Government Accountability Office.
Item Type: Refine your search to only Report
open access

Electronic motion in the pre-oscillation phase of a smooth bore magnetron

Description: The calculation of the electronic motion in the pre-oscillation phase of a smooth bore magnetron is the problem of calculating the electronic motion in the region between two concentric cylinders with an applied radial electric field and a constant axial B/sub z/ magnetic field. The inner cylinder represents the electron emitting cathode and the outer cylinder represents the anode. The emission is assumed to be space charge limited. This results in an electronic cloud surrounding the cathode. T… more
Date: September 6, 1979
Creator: Garelis, E. & Hickman, R.B.
Item Type: Refine your search to only Report
open access

Electropholic Transition Metal Complexes: Catalysis of Isotope Exchange. April 1, 1992 - December 3, 1996. Final Report.

Description: The central aim of this project is to exploit transition metal dihydrogen complexes to develop catalysts for isotope exchange reactions between hydrogen and substrates such as water. The authors have partially met this goal by the synthesis of novel cationic rhenium complexes of the form [Re(CO){sub 3}(PR{sub 3}){sub 2}(H{sub 2})]{sup +}. These complexes bind hydrogen somehwat more strongly than the neutral tungsten analogs but also activate the bound H{sub 2} to heterolytic cleavage. Thus rapi… more
Date: April 6, 1997
Creator: Heinekey, D. Michael
Item Type: Refine your search to only Report
open access

Electroproduction of Photons and of Pawns on the Proton in Quadrimoment of Transfer Q2=1.0GeV2. Measure Cross Sections and Extraction of Polarizabilities Generalities; Electroproduction de Photons et de Pions sur le Proton au Quadrimoment de Transfert Q2=1.0GeV2. Mesure des Sections Efficaces et Extraction des Polarisabilites Generalisees

Description: In hadronic physics, the nucleon structure and the quarks confinement are still topical issues. The neutral pion electroproduction and virtual Compton scattering (VCS) reactions allow us to access new observables that describe this structure. This work is focused on the VCS experiment performed at Jefferson Lab in 1998.
Date: November 6, 2001
Creator: Laveissiere, Geraud
Item Type: Refine your search to only Thesis or Dissertation
open access

Elementary and Secondary Education: Accountability and Flexibility in Federal Aid Proposals

Description: The 107th Congress is considering proposals to amend the Elementary and Secondary Education Act (ESEA). Much of the debate over these proposals has been focused on issues related to state and local accountability for, and flexibility in the use of, federal aid funds. Current federal elementary and secondary education assistance programs have a broad range of accountability requirements, including: targeting of resources on specific “high need” pupil groups, localities, or schools; limitations o… more
Date: September 6, 2001
Creator: Riddle, Wayne C.
Item Type: Refine your search to only Report
open access

Elements of a system for verifying a Comprehensive Test Ban

Description: The paper discusses the goals of a monitoring system for a CTB, its functions, the challenges to verification, discrimination techniques, and some recent developments. It is concluded technical, military and political efforts are required to establish and verify test ban treaties which will contribute to stability in the long term. It currently appears there will be a significant number of unidentified events. (ACR)
Date: March 6, 1987
Creator: Hannon, W.J.
Item Type: Refine your search to only Article
open access

Eliminating the Spot Dilution Due to Kicker Switching in DARHT-II

Description: To produce four short x-ray pulses for radiography, the second-axis of the Dual Axis Radiographic Hydrodynamic Test facility (DARHT-II) will use a fast kicker to select current pulses out of the 2-ms duration beam provided by the accelerator. Beam motion during the kicker voltage switching could lead to dilution of the time integrated beam spot and make the spot elliptical. A large elliptical x-ray source produced by those beams would degrade the resolution and make radiographic analysis diffic… more
Date: May 6, 2003
Creator: Chen, Y. J.; Chambers, F. W.; Paul, A. C.; Watson, A. & Weir, J. T.
Item Type: Refine your search to only Article
open access

ELIST 8.0 Transportation Model

Description: The Enhanced Logistics Intratheater Support Tool (ELIST) Version 8 is a software tool designed to allow military analysts to model the deployment of cargo and personnel into theaters of operation from ports of debarkation through staging areas and theater-staging bases to in-theater destinations, usually tactical assembly areas. This document defines the parameters and heuristics to be modeled. All design and implementation decisions are derived from this document. Validation and verification o… more
Date: March 6, 2002
Creator: Braun, M. B. & Van Groningen, C. N.
Item Type: Refine your search to only Report
open access

Elliptic integral evaluations of Bessel moments

Description: We record what is known about the closed forms for variousBessel function moments arising in quantum field theory, condensed mattertheory and other parts of mathematical physics. More generally, wedevelop formulae for integrals of products of six or fewer Besselfunctions. In consequence, we are able to discover and prove closed formsfor c(n,k) := Int_0 inf tk K_0 n(t) dt, with integers n = 1, 2, 3, 4 andk greater than or equal to 0, obtaining new results for the even momentsc3,2k and c4,2k . We… more
Date: January 6, 2008
Creator: Bailey, David H.; Borwein, Jonathan M.; Broadhurst, David & Glasser, M. L.
Item Type: Refine your search to only Article
open access

Elucidating the Molecular Basis and Regulation of Chromium(VI) Reduction by Shewanella oneidensis MR-1 and Resistance to Metal Toxicity Using Integrated Biochemical, Genomic and Proteomic Approaches

Description: Shewanella oneidensis MR-1 is a model environmental organism that possesses diverse respiratory capacities, including the ability to reduce soluble Cr(VI) to sparingly soluble, less toxic Cr(III). Chromate is a serious anthropogenic pollutant found in subsurface sediment and groundwater environments due to its widespread use in defense and industrial applications. Effective bioremediation of chromate-contaminated sites requires knowledge of the molecular mechanisms and regulation of heavy metal… more
Date: February 6, 2007
Creator: Thompson, Dorothea K. & Hettich, Robert
Item Type: Refine your search to only Report
open access

EM experiments for computational model validation for AH-1S Cobra Helicopter

Description: The effort described here describes a set of outdoor experiments performed on the AH-1S Cobra helicopter in order to validate and compare to the computational electromagnetic models of the bulk structure of the airframe in the frequency bands up to 4 GHz. Also included in this were coupling measurements to wires and cables inside of the airframe and various cavity to HPM pulse in this frequency range as part of other activities. Additionally, the low power modeling compression will be completed… more
Date: April 6, 1997
Creator: Nelson, S. D.
Item Type: Refine your search to only Article
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