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A Novel Technology for Fabricating Customizable VLSI Artificial Neural Network Chips

Description: This paper describes an implementation of hardware neural networks using highly linear thin-film resistor technology and an 8-bit binary weight circuit to produce customizable artificial neural network chips and systems. These neural networks are programmed using precision laser cutting and deposition. The fast turnaround of laser-based customization allows us to explore different neural network architectures and to rapidly program the synaptic weights. Our customizable chip allows us to expand… more
Date: February 5, 1992
Creator: Fu, Chi Yung; Law, Benjamin; Chapline, George & Swenson, Dick
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Partner: UNT Libraries Government Documents Department
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K-shell emission from 140 femtosecond laser-produced plasmas created from porous aluminum targets

Description: The K-shell emission from flat and porous aluminum targets is used to infer the efficiency of creating a high temperature (>100eV), thermal plasma with 800 nm, 140 fs laser light. The K-shell emission from flat aluminum targets is fond to be significantly less than that of the porous targets, implying a lower temperature and less efficient coupling between the target and ultra-short pulse laser light.
Date: June 5, 1992
Creator: Shepherd, R.; Price, D.; White, B.; Osterheld, A.; Walling, R.; Slaughter, D. et al.
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Partner: UNT Libraries Government Documents Department
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Dihadron Azimuthal Correlation from Collins Effect in Unpolarized Hadron Collisions

Description: We study the dihadron azimuthal correlation produced nearly back-to-back in unpolarized hadron collisions, arising from the product of two Collins fragmentation functions. Using the latest Collins fragmentation functions extracted from the global analysis of available experimental data, we make predictions for the azimuthalcorrelation of two-pion production in pp collisions at RHIC energies. We find that the correlation is sizable in the mid-rapidity region for moderate jet transverse momentum.
Date: January 5, 2010
Creator: Yuan, Feng
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Partner: UNT Libraries Government Documents Department
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Systemsize dependence of associated yields in hadron-triggered jets

Description: We present results on the system size dependence of high transverse momentum di-hadron correlations at {radical}s{sub NN} = 200 GeV as measured by STAR at RHIC. Measurements in d+Au, Cu+Cu and Au+Au collisions reveal similar jet-like correlation yields at small angular separation ({Delta}{phi} {approx} 0, {Delta}{eta} {approx} 0) for all systems and centralities. Previous measurements have shown that the away-side yield is suppressed in heavy-ion collisions. We present measurements of the away-… more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Phases of Augmented Hadronic Light-Front Wave Functions

Description: It is an important question whether the final/initial state gluonic interactions which lead to naive-time-reversal-odd single-spin asymmetries and diffraction at leading twist can be associated in a definite way with the light-front wave function hadronic eigensolutions of QCD. We use light-front time-ordered perturbation theory to obtain augmented light-front wave functions which contain an imaginary phase which depends on the choice of advanced or retarded boundary condition for the gauge … more
Date: January 5, 2010
Creator: Yuan, Feng; Brodsky, S.J.; Pasquini, B. & Xiao, B.-W.
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Partner: UNT Libraries Government Documents Department
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Identified high-pT spectra in Cu+Cu collisions at sqrt sNN=200 GeV

Description: We report new results on identified (anti)proton and charged pion spectra at large transverse momenta (3 < p{sub T} < 10 GeV/c) from Cu+Cu collisions at {radical}s{sub NN} = 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider (RHIC). This study explores the system size dependence of two novel features observed at RHIC with heavy ions: the hadron suppression at high-p{sub T} and the anomalous baryon to meson enhancement at intermediate transverse momenta. Both phenomena … more
Date: July 5, 2010
Creator: STAR Collaboration
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Partner: UNT Libraries Government Documents Department
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Observation of pi+pi-pi+pi- photoproduction in ultraperipheral heavy-ion collisions at sqrt sNN = 200 GeV at the STAR detector

Description: We present a measurement of {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} photonuclear production in ultra-peripheral Au-Au collisions at {radical}s{sub NN} = 200 GeV from the STAR experiment. The {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} final states are observed at low transverse momentum and are accompanied by mutual nuclear excitation of the beam particles. The strong enhancement of the production cross section at low transverse momentum is consistent with coherent photoproduction. The {p… more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Long range rapidity correlations and jet production in high energy nuclear collisions

Description: The STAR Collaboration at RHIC presents a systematic study of high transverse momentum charged di-hadron correlations at small azimuthal pair separation {Delta}{phi}, in d+Au and central Au+Au collisions at {radical}s{sub NN} = 200 GeV. Significant correlated yield for pairs with large longitudinal separation {Delta}{eta} is observed in central Au+Au, in contrast to d+Au collisions. The associated yield distribution in {Delta}{eta} x {delta}{phi} can be decomposed into a narrow jet-like peak at… more
Date: July 5, 2010
Creator: STAR Collaboration
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Partner: UNT Libraries Government Documents Department
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Simulations of a stretching bar using a plasticity model from the shear transformation zone theory

Description: An Eulerian simulation is developed to study an elastoplastic model of amorphous materials that is based upon the shear transformation zone theory developed by Langer and coworkers. In this theory, plastic deformation is controlled by an effective temperature that measures the amount of configurational disorder in the material. The simulation is used to model ductile fracture in a stretching bar that initially contains a small notch, and the effects of many of the model parameters are examined.… more
Date: June 5, 2010
Creator: Rycroft, Chris H. & Gibou, Frederic
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Partner: UNT Libraries Government Documents Department
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Time-resolved Studies of Phase Transition Dynamics in Strongly Correlated Manganites

Description: Ultrafast light pulses can be used to control electronic, magnetic and structural phases of complex solids. Here, we investigate the dynamics of insulator-metal phase transitions in colossal magnetoresistive (CMR) manganites by a combination of femtosecond visible-to-midinfrared pump-probe techniques and transport measurements. We show that an insulator-metal transition can be stimulated in CMR manganites by both above bandgap excitation and selective excitation of individual vibrational degree… more
Date: December 5, 2008
Creator: Rini, M.; Tobey, R.; Dean, N.; Wall, S.; Ehrke, H.; Zhu, Y. et al.
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Partner: UNT Libraries Government Documents Department
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Observation of charge-dependent azimuthal correlations and possible local strong parity violation in heavy-ion collisions

Description: Parity-odd domains, corresponding to non-trivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the orbital momentum of the system created in non-central collisions. To study this effect, we investigate a three particle mixed harmonics azimuthal correlator which is a {Rho}-even observable, but directly sensitive to the charge separation effect. We report measurements of … more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Growth of Long Range Forward-Backward Multiplicity Correlations with Centrality in Au+Au Collisions at sqrt sNN = 200 GeV

Description: Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au+Au and p+p collisions at {radical}s{sub NN} = 200 GeV. Strong short and long range correlations (LRC) are seen in central Au+Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short range correlations are observed in peripheral Au+Au collisions. Both the Dual Parton Model (DPM) and the Color Glass Condensate (CGC) predict the existence of the long r… more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Bacterial Microcompartments

Description: Bacterialmicrocompartments (BMCs) are organelles composed entirely of protein. They promote specific metabolic processes by encapsulatingand colocalizing enzymes with their substrates and cofactors, by protecting vulnerable enzymes in a defined microenvironment, and bysequestering toxic or volatile intermediates. Prototypes of the BMCsare the carboxysomes of autotrophic bacteria. However, structures of similarpolyhedral shape are being discovered in an ever-increasing number of heterotrophi… more
Date: June 5, 2010
Creator: Kerfeld, Cheryl A.; Heinhorst, Sabine & Cannon, Gordon C.
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Partner: UNT Libraries Government Documents Department
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The FERMI@Elettra free-electron-laser source for coherent X-ray physics: photon properties, beam transport system, and applications

Description: FERMI@Elettra is comprised of two free electron lasers (FELs) that will generate short pulses (tau ~;; 25 to 200 fs) of highly coherent radiation in the XUV and soft X-ray region. The use of external laser seeding together with a harmonic upshift scheme to obtain short wavelengths will give FERMI@Elettra the capability to produce high quality, longitudinal coherent photon pulses. This capability together with the possibilities of temporal synchronization to external lasers and control of the ou… more
Date: April 5, 2010
Creator: Allaria, Enrico; Callegari, Carlo; Cocco, Daniele; Fawley, William M.; Kiskinova, Maya; Masciovecchio, Claudio et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Identified particle production, azimuthal anisotropy, and interferometry measurements in Au+Au collisions at sqrt sNN = 9.2 GeV

Description: We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from Au+Au collisions below the nominal injection energy at the Relativistic Heavy-Ion Collider (RHIC) facility. The data were collected using the large acceptance STAR detector at {radical}s{sub NN} = 9.2 GeV from a test run of the collider in the year 2008. Midrapidity results on multiplicity density (dN/dy) in rapidity (y), average transverse momentum (<p{sub T}>), particle … more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Antiferromagnetic exchange bias of a ferromagnetic semiconductor by a ferromagnetic metal

Description: We demonstrate an exchange bias in (Ga,Mn)As induced by antiferromagnetic coupling to a thin overlayer of Fe. Bias fields of up to 240 Oe are observed. Using element-specific x-ray magnetic circular dichroism measurements, we distinguish an interface layer that is strongly pinned antiferromagnetically to the Fe. The interface layer remains polarized at room temperature.
Date: November 5, 2009
Creator: Olejnik, K.; Wadley, P.; Haigh, J.; Edmonds, K. W.; Campion, R. P.; Rushforth, A. W. et al.
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Partner: UNT Libraries Government Documents Department
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Center of mass energy and system-size dependence of photon production at forward rapidity at RHIC

Description: We present the multiplicity and pseudorapidity distributions of photons produced in Au+Au and Cu+Cu collisions at {radical}s{sub NN} = 62.4 and 200 GeV. The photons are measured in the region -3.7 < {eta} < -2.3 using the photon multiplicity detector in the STAR experiment at RHIC. The number of photons produced per average number of participating nucleon pairs increases with the beam energy and is independent of the collision centrality. For collisions with similar average numbers of par… more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Improved Modeling and Understanding of Diffusion-Media Wettability on Polymer-Electrolyte-Fuel-Cell Performance

Description: A macroscopic-modeling methodology to account for the chemical and structural properties of fuel-cell diffusion media is developed. A previous model is updated to include for the first time the use of experimentally measured capillary pressure -- saturation relationships through the introduction of a Gaussian contact-angle distribution into the property equations. The updated model is used to simulate various limiting-case scenarios of water and gas transport in fuel-cell diffusion media. An… more
Date: March 5, 2010
Creator: Weber, Adam
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Partner: UNT Libraries Government Documents Department
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Azimuthal Charged-Particle Correlations and Possible Local Strong Parity Violation

Description: Parity-odd domains, corresponding to non-trivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three particle azimuthal correlator which is a {Rho} even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au+… more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Charged and strange hadron elliptic flow in Cu+Cu collisions at sqrt sNN = 62.4 and 200 GeV

Description: We present the results of an elliptic flow, v{sub 2}, analysis of Cu+Cu collisions recorded with the STAR detector at RHIC at {radical}s{sub NN} = 62.4 and 200 GeV. Elliptic flow as a function of transverse momentum, v{sub 2}(p{sub T}), is reported for different collision centralities for charged hadrons h{sup {+-}}, and strangeness containing hadrons K{sub S}{sup 0}, {Lambda}, {Xi}, {phi} in the midrapidity region |{eta}| < 1.0. Significant reduction in systematic uncertainty of the measure… more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effect of Vinylene Carbonate on Graphite Anode Cycling Efficiency

Description: Vinylene Carbonate (VC) was added to the electrolyte in graphite-lithium half-cells. We report its effect on the coulombic efficiency (as capacity shift) of graphite electrodes under various formation cycling conditions. Cyclic voltammetry on glassy carbon showed that VC passivates the electrode against electrolyte reduction. The dQ/dV plots of the first lithiation of the graphite suggest that VC alters the SEI layer, and that by varying the cell formation rate, the initial ratio of ethylene ca… more
Date: May 5, 2009
Creator: Ridgway, Paul; Zheng, Honghe; Liu, Gao; Song, Xiangun; Ross, Philip & Battaglia, Vincent
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Partner: UNT Libraries Government Documents Department
open access

Observation of an Antimatter Hypernucleus

Description: Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons - composed of an antiproton, antineutron, and antilambda hyperon - produced by colliding gold nuclei at high energy. Our analysis yields 70 {+-} 17 antihypertritons ({sub {bar {Lambda}}}{sup 3}{bar H}) and 157 {+-} 30 hypertritons ({sub {Lambda}}{su… more
Date: July 5, 2010
Creator: STAR Collaboration
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Partner: UNT Libraries Government Documents Department
open access

Longitudinal Spin Transfer to Lambda and Lambda bar Hyperons in Polarized Proton-Proton Collisions at sqrt s = 200 GeV

Description: The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {Lambda} and {bar {Lambda}} hypersons has been measured for the first time in proton-proton collisions at {radical}s = 200 GeV with the STAR detector at RHIC. The measurements cover pseudorapidity, {eta}, in the range |{eta}| < 1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL} = -0.03{+-}0.13(stat){+-}0.04(syst) for inclusive {Lambda} and D{sub LL} = -0.… more
Date: July 5, 2010
Creator: STAR Collaboration
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Partner: UNT Libraries Government Documents Department
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Unvail the Mysterious of the Single Spin Asymmetry

Description: Single transverse-spin asymmetry in high energy hadronic reaction has been greatly investigated from both experiment and theory sides in the last few years. In this talk, I will summarize some recent theoretical developments, which, in my opinion, help to unvail the mysterious of the single spin asymmetry.
Date: January 5, 2010
Creator: Yuan, Feng
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Partner: UNT Libraries Government Documents Department
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