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open access

3-D full waveform inversion of seismic data; Part I. Theory

Description: Full waveform inversion of seismic data is a challenging subject partly because of the lack of precise knowledge of the source. Since currently available approaches involve some form of approximations to the source, inversion results are subject to the quality and the choice of the source information used. A new full waveform inversion scheme has been introduced (Lee and Kim, 2003) using normalized wavefield for simple two-dimensional (2-D) scalar problems. The method does not require source in… more
Date: May 12, 2003
Creator: Lee, Ki Ha
open access

3-D surface profile measurements of large x-ray synchrotron radiation mirrors using stitching interferometry.

Description: Stitching interferometry, using small-aperture, high-resolution, phase-measuring interferometry, has been proposed for quite some time now as a metrology technique to obtain 3-dimensional profiles of surfaces of oversized optical components and substrates. The aim of this work is to apply this method to the specific case of long grazing-incidence x-ray mirrors, such as those used in beamlines at synchrotron radiation facilities around the world. Both fabrication and characterization of these mi… more
Date: September 12, 2002
Creator: Assoufid, L.; Bray, M.; Qian, J. & Shu, D.
open access

A 90-GHz Photoinjector

Description: Photocathode rf guns depend on mode locked laser systems to produce an electron beam at a given phase of the rf. In general, the laser pulse is less than {sigma}{sub z} = 10{sup o} of rf phase in length and the required stability is on the order of {Delta}{phi} = 1{sup o}. At 90 GHz (W-band), these requirements correspond to {sigma}{sub z} = 333 fsec and {Delta}{phi} = 33 fsec. Laser system with pulse lengths in the fsec regime are commercially available, the timing stability is a major concern… more
Date: September 12, 2005
Creator: Palmer, D. T.; Hogan, M. J.; Ferrario, M. & Serafini, L.
open access

2008 Co2 Assimilation in Plants: Genome to Biome Gordon Research Conference - August 17-22

Description: Formerly entitled 'CO2 Fixation and Metabolism in Green Plants', this long-standing Gordon Research Conference has been held on a triennial basis since 1976. In 1990 the participants decided to alternate between sites in the U.S. and outside the U.S. The 2005 conference was held in Europe at the Centre Paul Langevin in Aussois, France, so the 2008 conference returns to a U.S. site - the University of New England in Biddeford, Maine. The 2008 conference covers basic plant research related to pho… more
Date: August 12, 2009
Creator: Maroney, James V.
open access

The 2mrad Crossing Angle Interaction Region and Extraction Line

Description: A complete optics design for the 2mrad crossing angle interaction region and extraction line was presented at Snowmass 2005. Since this time, the design task force has been working on developing and improving the performance of the extraction line. The work has focused on optimizing the final doublet parameters and on reducing the power losses resulting from the disrupted beam transport. In this paper, the most recent status of the 2mrad layout and the corresponding performance are presented.
Date: July 12, 2006
Creator: Appleby, R.; U., Manchester; Angal-Kalinin, D.; Tech, /Cockcroft Inst. Accel. Sci.; Dadoun, O.; Bambade, P. et al.
open access

7Be(p,gamma)8B S-factor from Ab Initio Wave Functions

Description: There has been a significant progress in ab initio approaches to the structure of light nuclei. Starting from realistic two- and three-nucleon interactions the ab initio no-core shell model (NCSM) predicts low-lying levels in p-shell nuclei. It is a challenging task to extend ab initio methods to describe nuclear reactions. We present here a brief overview of the first steps taken toward nuclear reaction applications. In particular, we discuss our calculation of the {sup 7}Be(p,{gamma}){sup 8}B… more
Date: October 12, 2006
Creator: Navratil, P; Bertulani, C A & Caurier, E
open access

Accelerator-based validation of shielding codes

Description: The space radiation environment poses risks to astronaut health from a diverse set of sources, ranging from low-energy protons and electrons to highly-charged, high-energy atomic nuclei and their associated fragmentation products, including neutrons. The low-energy protons and electrons are the source of most of the radiation dose to Shuttle and ISS crews, while the more energetic particles that comprise the Galactic Cosmic Radiation (protons, He, and heavier nuclei up to Fe) will be the domina… more
Date: August 12, 2002
Creator: Zeitlin, Cary; Heilbronn, Lawrence; Miller, Jack & Wilson, John W.
open access

Accelerator Mass Spectrometry Allows for Cellular Quantification of Doxorubicin at Femtomolar Concentrations

Description: Accelerator mass spectrometry (AMS) is a highly sensitive analytical methodology used to quantify the content of radioisotopes, such as {sup 14}C, in a sample. The primary goals of this work were to demonstrate the utility of AMS in determining cellular [{sup 14}C]doxorubicin (DOX) concentrations and to develop a sensitive assay that is superior to high performance liquid chromatography (HPLC) for the quantification of DOX at the tumor level. In order to validate the superior sensitivity of AMS… more
Date: April 12, 2005
Creator: DeGregorio, M W; Dingley, K H; Wurz, G T; Ubick, E & Turteltaub, K W
open access

Access Grid: Immersive Group-to-Group Collaborative Visualization

Description: Immersive projection displays have played an important role in enabling large-format virtual reality systems such as the CAVE and CAVE like devices and the various immersive desks and desktop-like displays. However, these devices have played a minor role so far in advancing the sense of immersion for conferencing systems. The Access Grid project led by Argonne is exploring the use of large-scale projection based systems as the basis for building room oriented collaboration and semi-immersive vi… more
Date: July 12, 2000
Creator: Childers, Lisa; Disz, Terry; Olson, Robert; Papka, Michael E.; Stevens, Rick & Udeshi, Tushar
open access

Accessing Ultra-High Pressure, Quasi-Isentropic States of Matter

Description: A new approach to the study of material strength of metals at extreme pressures has been developed on the Omega laser, using a ramped plasma piston drive. The laser drives a shock through a solid plastic reservoir that unloads at the rear free surface, expands across a vacuum gap, and stagnates on the metal sample under study. This produces a gently increasing ram pressure, compressing the sample nearly isentropically. The peak pressure on the sample, inferred from VISAR measurements of velocit… more
Date: November 12, 2004
Creator: Lorenz, K. T.; Edwards, M. J.; Glendinning, S. G.; Ho, D. D.; Jankowski, Alan Frederic; McNaney, J. et al.
open access

Accuracy of Projection Methods for the Incompressible Navier-Stokes Equations

Description: Numerous papers have appeared in the literature over the past thirty years discussing projection-type methods for solving the incompressible Navier-Stokes equations. A recurring difficulty encountered is the choice of boundary conditions for the intermediate or predicted velocity in order to obtain at least second order convergence. A further issue is the formula for the pressure correction at each timestep. A simple overview is presented here based on recently published results by Brown, Corte… more
Date: June 12, 2001
Creator: Brown, D L
open access

Achieving High Dopant Concentrations in Si: First Principles Simulations

Description: In this paper we discuss methods to obtain high dopant concentrations during processing of Si devices. The possibility of increasing the solubility of B in Si by misfit stress is investigated. The enthalpy of B atoms is calculated, with and without stress, using density functional theory. A second approach, the trapping of excess dopant atoms during deposition of Si, is also considered. For this purpose, the enthalpies of several dopant species in sites near the surface are calculated.
Date: August 12, 2002
Creator: Centoni, S A; Sadigh, B; Caturla, M J; Gilmer, G H & Diaz de la Rubia, T
open access

Acid Catalysis in Basic Solution: A Supramolecular Host PromotesOrthoformate Hydrolysis

Description: Though many enzymes can promote chemical reactions by tuning substrate properties purely through the electrostatic environment of a docking cavity, this strategy has proven challenging to mimic in synthetic host-guest systems. Here we report a highly-charged, water soluble, metal-ligand assembly with a hydrophobic interior cavity that thermodynamically stabilizes protonated substrates and consequently catalyzes the normally acidic hydrolysis of orthoformates in basic solution, with rate acceler… more
Date: December 12, 2007
Creator: Pluth, Michael D.; Bergman, Robert G. & Raymond, Kenneth N.
open access

ACTION AND PHASE ANALYSIS TO DETERMINE SEXTUPOLE ERRORS IN RHIC AND THE SPS.

Description: Success in the application of the action and phase analysis to find linear errors at RHIC Interaction Regions [1] has encouraged the creation of a technique based on the action and phase analysis to find non linear errors. In this paper we show the first attempt to measure the sextupole components at RHIC interaction regions using the action and phase method. Experiments done by intentionally activating sextupoles in RHIC and in SPS [2] will also be analyzed with this method. First results have… more
Date: May 12, 2003
Creator: Cardona, J.; Peggs, S.; Satogata, T. & Tomas, R.
open access

Adaptable Assertion Checking for Scientific Software Components

Description: We present a proposal for lowering the overhead of interface contract checking for science and engineering applications. Run-time enforcement of assertions is a well-known technique for improving the quality of software; however, the performance penalty is often too high for their retention during deployment, especially for long-running applications that depend upon iterative operations. With an efficient adaptive approach the benefits of run-time checking can continue to accrue with minimal ov… more
Date: March 12, 2004
Creator: Dahlgren, T L & Devanbu, P T
open access

Adaptive compensation of atmospheric turbulence utilizing an interferometric wave-front sensor and a high-resolution MEMS-based spatial light modulator

Description: Horizontal path correction of optical beam propagation presents a severe challenge to adaptive optics systems due to the short transverse coherence length and the high degree of scintillation incurred by propagation along these paths. The system presented operates with nearly monochromatic light. It does not require a global reconstruction of the phase, thereby eliminating issues with branch points and making its performance relatively unaffected by scintillation. The systems pixel count, 1024,… more
Date: August 12, 2004
Creator: Baker, K.; Stappaerts, E.; Gavel, D.; Tucker, J.; Silva, D.; Wilks, S. et al.
open access

An Adaptive Path Planning Algorithm for Cooperating Unmanned Air Vehicles

Description: An adaptive path planning algorithm is presented for cooperating Unmanned Air Vehicles (UAVs) that are used to deploy and operate land-based sensor networks. The algorithm employs a global cost function to generate paths for the UAVs, and adapts the paths to exceptions that might occur. Examples are provided of the paths and adaptation.
Date: September 12, 2000
Creator: Cunningham, C.T. & Roberts, R.S.
open access

Adiabatic Heat of Hydration Calorimetric Measurements for Reference Saltstone Waste

Description: The production of nuclear materials for weapons, medical, and space applications from the mid-1950's through the late-1980's at the Savannah River Site (SRS) generated approximately 35 million gallons of liquid high-level radioactive waste, which is currently being processed into vitrified glass for long-term storage. Upstream of the vitrification process, the waste is separated into three components: high activity insoluble sludge, high activity insoluble salt, and very low activity soluble sa… more
Date: January 12, 2006
Creator: Bollinger, James
open access

AdS/QCD and Its Holographic Light-Front Partonic Representation

Description: Starting from the Hamiltonian equation of motion in QCD we find a single variable light-front equation for QCD which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. This light-front wave equation is equivalent to the equations of motion which describe the propagation of spin-J modes on anti-de Sitter (AdS) space.
Date: November 12, 2008
Creator: de Teramond, Guy F. & Brodsky, Stanley J.
open access

ADVANCEMENT OF THE RHIC BEAM ABORT KICKER SYSTEM.

Description: As one of the most critical system for RHIC operation, the beam abort kicker system has to be highly available, reliable, and stable for the entire operating range. Along with the RHIC commission and operation, consistent efforts have been spend to cope with immediate issues as well as inherited design issues. Major design changes have been implemented to achieve the higher operating voltage, longer high voltage hold-off time, fast retriggering and redundant triggering, and improved system prot… more
Date: May 12, 2003
Creator: ZHANG,W. AHRENS,L. MI,J. OERTER,B. SANDBERG,J. WARBURTON,D.
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