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Non-Equilibrium Creation of Intrinsically Localized Vibrations in Uranium Using X-Ray and Neutron Scattering

Description: In an anharmonic crystal, large-amplitude vibrational fluctuations on the scale of the lattice spacing can develop frequencies that do not resonate with the normal modes, causing energy to become trapped in intrinsically localized modes (ILMs)--also called 'discrete breathers' or 'lattice solitons'. This mechanism has been observed in analogous systems on a larger scale, but unambiguous sightings in atomic lattice vibrations, where quantum mechanics may play a role, have proved difficult. Two c… more
Date: July 2, 2007
Creator: Manley, M.; Alatas, A.; Trouw, F.; Leu, B. M.; Lynn, J. W.; Chen, Y. et al.
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Partner: UNT Libraries Government Documents Department
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Multiscale modeling of MEMS dynamics and failure

Description: This work studies multiscale phenomena in silicon micro-resonators which comprise the mechanical components of next-generation Micro-Electro-Mechanical Systems (MEMS). Unlike their larger relatives, the behavior of these sub-micron MEMS is not described well by conventional continuum models and finite elements, but it is determined appreciably by the interplay between physics at the Angstrom, nanometer and micron scales. As device sizes are reduced below the micron scale, atomistic processes ca… more
Date: October 2, 2000
Creator: Rudd, R E
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Partner: UNT Libraries Government Documents Department
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Spawning Habitat Studies of Hanford Reach Fall Chinook Salmon (Oncorhynchus tshawytscha), Final Report.

Description: The Pacific Northwest National Laboratory conducted this study for the Bonneville Power Administration (BPA) with funding provided through the Northwest Power and Conservation Council(a) and the BPA Fish and Wildlife Program. The study was conducted in the Hanford Reach of the Columbia River. The goal of study was to determine the physical habitat factors necessary to define the redd capacity of fall Chinook salmon that spawn in large mainstem rivers like the Hanford Reach and Snake River. The … more
Date: March 2, 2009
Creator: Geist, David R.; Arntzen, Evan V. & Chien, Yi-Ju (Pacific Northwest National Laboratory)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Laurentide Ice Sheet meltwater and abrupt climate change during the last glaciation

Description: A leading hypothesis to explain abrupt climate change during the last glacial cycle calls on fluctuations in the margin of the North American Laurentide Ice Sheet (LIS), which may have routed freshwater between the Gulf of Mexico (GOM) and North Atlantic, affecting North Atlantic Deep Water (NADW) variability and regional climate. Paired measurements of {delta}O and Mg/Ca of foraminiferal calcite from GOM sediments reveal five episodes of LIS meltwater input from 28-45 thousand years ago (ka) t… more
Date: October 2, 2005
Creator: Hill, H W; Flower, B P; Quinn, T M; Hollander, D J & Guilderson, T P
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Event-by-event hexb pt hexb fluctuations in Au-Au collisions atsqrt(sNN) = 130 GeV

Description: We present the first large-acceptance measurement of event-wise <p{sub t}> fluctuations in Au-Au collisions at {radical}s{sub NN} = 130 GeV. Significant nonstatistical fluctuations are observed. The measured fractional r.m.s. width excess of the event-wise <p{sub t}> distribution for the 15% most-central events for charged hadrons within |{eta}| < 1 and 0.15 {le} p{sub t} {le} 2 GeV/c is 13.7 {+-} 0.1(stat) {+-}1.3(syst)% relative to a statistical reference. The variation of char… more
Date: September 2, 2003
Creator: Adams, J.; Adler, C.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
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Partner: UNT Libraries Government Documents Department
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Nucleosynthesis in a baryon-inhomogeneous universe with coupled baryon diffusion

Description: Detailed calculations of big-bang nucleosynthesis in baryon-inhomogeneous universes show that {Omega}{sub b} can be considerably larger than its limit from standard big-bang nucleosynthesis. Such results require that late-time hydrodynamic effects deplete overproduction of {sup 7}Li and that the QCD surface tension be near the cube of the QCD coexistence temperature for fluctuations of the correct length scales to arise. 15 refs., 1 fig.
Date: August 2, 1990
Creator: Meyer, B.S.
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Partner: UNT Libraries Government Documents Department
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4D Emittance Measurements Using Multiple Wire and Waist Scan Methods in the ATF Extraction Line

Description: Emittance measurements performed in the diagnostic section of the Accelerator Test Facility (ATF) extraction line since 1998 led to vertical emittances three times larger than the expected ones, with a strong dependence on intensity. An experimental program is pursued to investigate potential sources of emittance growth and find possible remedies. This requires efficient and reliable emittance measurement techniques. In the past, several phase-space reconstruction methods developed at SLAC and … more
Date: November 2, 2011
Creator: Rimbault, C.; Bambade, P.; Brossard, J.; Alabau, M.; Kuroda, S.; Scarfe, A. et al.
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Partner: UNT Libraries Government Documents Department
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Air Quality and Road Emission Results for Fort Stewart, Georgia

Description: The Directorate of Public Works Environmental & Natural Resources Division (Fort Stewart /Hunter Army Airfield) contracted with the Pacific Northwest National Laboratory (PNNL) to monitor particulate matter (PM) concentrations on Fort Stewart, Georgia. The purpose of this investigation was to establish a PM sampling network using monitoring equipment typically used in U.S. Environmental Protection Agency (EPA) ''saturation sampling'', to determine air quality on the installation. In this initia… more
Date: February 2, 2004
Creator: Kirkham, Randy R.; Driver, Crystal J.; Chamness, Mickie A. & Barfuss, Brad C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Fast Implementation of Matched Filter Based Automatic Alignment Image Processing

Description: Video images of laser beams imprinted with distinguishable features are used for alignment of 192 laser beams at the National Ignition Facility (NIF). Algorithms designed to determine the position of these beams enable the control system to perform the task of alignment. Centroiding is a common approach used for determining the position of beams. However, real world beam images suffer from intensity fluctuation or other distortions which make such an approach susceptible to higher position meas… more
Date: April 2, 2008
Creator: Awwal, A. S.; Rice, K. & Taha, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Neutron Scattering Studies of Vortex Matter in Type-II Superconductors

Description: The proposed program is an experimental study of the fundamental properties of Abrikosov vortex matter in type-II superconductors. Most superconducting materials used in applications such as MRI are type II and their transport properties are determined by the interplay between random pinning, interaction and thermal fluctuation effects in the vortex state. Given the technological importance of these materials, a fundamental understanding of the vortex matter is necessary. The vortex lines in ty… more
Date: February 2, 2012
Creator: Ling, X.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Magnetic and Charge Fluctuations in High-T(Sub c) Superconductors

Description: Neutron scattering has been used to study the spin fluctuations in the YBaCuO and BiSrCaCuO materials. Evidence is found for both incommensurate fluctuations and a commensurate resonance excitation. Measurements on the lattice dynamics for YBaCuO show incommensurate structure that appears to stem from charge fluctuations that are associated with the spin fluctuations.
Date: June 2, 1998
Creator: Chakoumakos, B.C.; Dogan, F. & Mook, H.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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