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Articles 27511 - 27540 of 36719

Full-Text Articles in Physical Sciences and Mathematics

Exotic Versus Conventional Scaling And Universality In A Disordered Bilayer Quantum Heisenberg Antiferromagnet, Rastko Sknepnek, Thomas Vojta, Matthias Vojta Aug 2004

Exotic Versus Conventional Scaling And Universality In A Disordered Bilayer Quantum Heisenberg Antiferromagnet, Rastko Sknepnek, Thomas Vojta, Matthias Vojta

Physics Faculty Research & Creative Works

We present Monte Carlo simulations of a two-dimensional bilayer quantum Heisenberg antiferromagnet with random dimer dilution. In contrast with exotic scaling scenarios found in other random quantum systems, the quantum phase transition in this system is characterized by a finite-disorder fixed point with power-law scaling. After accounting for corrections to scaling, with a leading irrelevant exponent of ω ≈ 0.48, we find universal critical exponents z = 1.310(6) and ν = 1.16(3). We discuss the consequences of these findings and suggest new experiments.

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Inhomogeneous Fragmentation Of The Rolling Tachyon, Gary Felder, Lev Kofman Aug 2004

Inhomogeneous Fragmentation Of The Rolling Tachyon, Gary Felder, Lev Kofman

Physics: Faculty Publications

Dirac-Born-Infeld type effective actions reproduce many aspects of string theory classical tachyon dynamics of unstable Dp-branes. The inhomogeneous tachyon field rolling from the top of its potential forms topological defects of lower codimensions. In between them, as we show, the tachyon energy density fragments into a p-dimensional web-like high density network evolving with time. We present an analytic asymptotic series solution of the non-linear equations for the inhomogeneous tachyon and its stress energy. The generic solution for a tachyon field with a runaway potential in arbitrary dimensions is described by the free streaming of noninteracting massive particles whose initial velocities …

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Vertical Nanowire Transistors With Low Leakage Current, Jie Chen, M. C. Lux-Steiner, Rolf Kӧnenkamp, S. Klaumünzer Aug 2004

Vertical Nanowire Transistors With Low Leakage Current, Jie Chen, M. C. Lux-Steiner, Rolf Kӧnenkamp, S. Klaumünzer

Physics Faculty Publications and Presentations

A vertical field-effect transistor based on semiconductor nanowires is reported. The fabrication of the device uses a self-supporting flexible nanostructured polymer foil as a template and an electrochemical growth technique for the preparation of the semiconductor. The fabrication process is substantially simpler, and the mechanical robustness is strongly increased as compared to the original device. The channel region of the transistor has a diameter of ∼100 nm and a length of ∼50 nm. Operation in the hole depletion mode allows a change of the transfer conductance by ∼50% when the gate voltages is changed in the range ∓1 V. The …

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Entropy And The Approach To The Thermodynamic Limit In Three-Dimensional Simplicial Gravity, Simon Catterall, John B. Kogut, R. Renken Aug 2004

Entropy And The Approach To The Thermodynamic Limit In Three-Dimensional Simplicial Gravity, Simon Catterall, John B. Kogut, R. Renken

Physics - All Scholarship

We present numerical results supporting the existence of an exponential bound in the dynamical triangulation model of three-dimensional quantum gravity.Both the critical coupling and various other quantities show a slow power law approach to the infinite volume limit.

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Broadening Of A Nonequilibrium Phase Transition By Extended Structural Defects, Thomas Vojta Aug 2004

Broadening Of A Nonequilibrium Phase Transition By Extended Structural Defects, Thomas Vojta

Physics Faculty Research & Creative Works

We study the effects of quenched extended impurities on nonequilibrium phase transitions in the directed percolation universality class. We show that these impurities have a dramatic effect: they completely destroy the sharp phase transition by smearing. This is caused by rare strongly coupled spatial regions which can undergo the phase transition independently from the bulk system. We use extremal statistics to determine the stationary state as well as the dynamics in the tail of the smeared transition, and we illustrate the results by computer simulations.

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Casimir Force Between Eccentric Cylinders, D. A. R. Dalvit, F. C. Lombardo, F. D D. Mazzitelli, R Onofrio Aug 2004

Casimir Force Between Eccentric Cylinders, D. A. R. Dalvit, F. C. Lombardo, F. D D. Mazzitelli, R Onofrio

Dartmouth Scholarship

We consider the Casimir interaction between a cylinder and a hollow cylinder, both conducting, with parallel axis and slightly different radii. The Casimir force, which vanishes in the coaxial situation, is evaluated for both small and large eccentricities using the proximity approximation. The cylindrical configuration offers various experimental advantages with respect to the parallel planes or the plane-sphere geometries, leading to favourable conditions for the search of extra-gravitational forces in the micrometer range and for the observation of finite-temperature corrections.

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Measurement Of The Polar-Angle Distribution Of Leptons From W Boson Decay As A Function Of The W Transverse Momentum In P̅P Collisions At √S=1.8 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Aug 2004

Measurement Of The Polar-Angle Distribution Of Leptons From W Boson Decay As A Function Of The W Transverse Momentum In P̅P Collisions At √S=1.8 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of the polar-angle distribution of leptons from W boson decay, as a function of the W transverse momentum. The measurement uses an 80±4 pb-1 sample of pp̅ collisions at √s =1.8 TeV collected by the CDF detector and includes data from both the W→e+ν and W→µ+ν decay channels. We fit the W boson transverse mass distribution to a set of templates from a Monte Carlo event generator and detector simulation in several ranges of the W transverse momentum. The measurement agrees with the standard model expectation, whereby the ratio of longitudinally to transversely …

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Observation Of The Narrow State X(3872) J/Ψ Π+ Π- In Pp̅ Collisions At √S =1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Aug 2004

Observation Of The Narrow State X(3872) J/Ψ Π+ Π- In Pp̅ Collisions At √S =1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report the observation of a narrow state decaying into J/ψ π+ π- and produced in 220 pb-1 of p̅p collisions at √s =1.96 TeV in the CDF II experiment. We observe 730±90 decays. The mass is measured to be 3871.3±0.7(stat)±0.4(syst) MeV/c2, with an observed width consistent with the detector resolution. This is in agreement with the recent observation by the Belle Collaboration of the X(3872) meson.

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Observation Of Isolated High-ET Photons In Deep Inelastic Scattering, S. Chekanov, M. Derrick, J. H. Loizides, S. Magill, S. Miglioranzi, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, N. Pavel, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, A. Montanari, R. Nania, F. Palmonari, A. Pesci, L. Rinaldi Aug 2004

Observation Of Isolated High-ET Photons In Deep Inelastic Scattering, S. Chekanov, M. Derrick, J. H. Loizides, S. Magill, S. Miglioranzi, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, N. Pavel, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, A. Montanari, R. Nania, F. Palmonari, A. Pesci, L. Rinaldi

Faculty Publications

First measurements of cross sections for isolated prompt photon production in deep inelastic ep scattering have been made using the ZEUS detector at the HERA electron-proton collider using an integrated luminosity of 121 pb -1. A signal for isolated photons in the transverse energy and rapidity ranges 5

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N-Type Boron-Carbide Semiconductor Polytype And Method Of Fabricating The Same, Peter A. Dowben, Anthony N. Caruso, Yaroslav B. Losovyj Aug 2004

N-Type Boron-Carbide Semiconductor Polytype And Method Of Fabricating The Same, Peter A. Dowben, Anthony N. Caruso, Yaroslav B. Losovyj

Peter Dowben Publications

A non-doped n-type boron carbide semiconductor polytype and a method of fabricating the same is provided. The n-type boron carbide polytype may be used in a device for detecting neutrons, electric power conversion, and pulse counting. Such a device may include an n-type boron carbide layer coupled with a substrate where the boron carbide may be an electrically active part of the device. This n-type boron carbide layer may be fabricated through the use of closo-1, 7-dicarbadodecaborane (metacarborane). Specifically, the non-doped n-type polytype may be fabricated using SR-CVD by placing the substrate in a vacuum chamber, cooling the substrate, introducing …

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Dna Strand Breaks Induced By 0–4 Ev Electrons: The Role Of Shape Resonances, Frédéric Martin, Paul Burrow, Zhongli Cai, Pierre Cloutier, Darel Hunting, Léon Sanche Aug 2004

Dna Strand Breaks Induced By 0–4 Ev Electrons: The Role Of Shape Resonances, Frédéric Martin, Paul Burrow, Zhongli Cai, Pierre Cloutier, Darel Hunting, Léon Sanche

Paul Burrow Publications

Collisions of 0– 4 eV electrons with thin DNA films are shown to produce single strand breaks. The yield is sharply structured as a function of electron energy and indicates the involvement of π* shape resonances in the bond breaking process. The cross sections are comparable in magnitude to those observed in other compounds in the gas phase in which π* electrons are transferred through the molecule to break a remote bond. The results therefore support aspects of a theoretical study by Barrios et al. [J. Phys. B 106, 7991 (2002)] indicating that such a mechanism could produce strand breaks …

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Inclusive Search For Anomalous Production Of High-PT Like-Sign Lepton Pairs In Pp̅ Collisions At √S =1.8 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Aug 2004

Inclusive Search For Anomalous Production Of High-PT Like-Sign Lepton Pairs In Pp̅ Collisions At √S =1.8 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report on a search for anomalous production of events with at least two charged, isolated, like-sign leptons, each with -pT>11 GeV/c using a 107 pb-1 sample of 1.8 TeV pp̅ collisions collected by the CDF detector. We define a signal region containing low background from standard model processes. To avoid bias, we fix the final cuts before examining the event yield in the signal region using control regions to test the Monte Carlo predictions. We observe no events in the signal region, consistent with an expectation of 0.63-0.07+0.84 events. We present 95% confidence …

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Boron-Carbide Solid State Neutron Detector And Method Of Using The Same, Peter A. Dowben, Shireen Adenwalla, Brian W. Robertson, Mengjun Bai Aug 2004

Boron-Carbide Solid State Neutron Detector And Method Of Using The Same, Peter A. Dowben, Shireen Adenwalla, Brian W. Robertson, Mengjun Bai

Peter Dowben Publications

A boron carbide solid state neutron detector and method of using the detector is disclosed, wherein the detector includes a layer of boron carbide wherein the boron carbide layer is an electrically active part of the detection device, a sensing mechanism inherent to said boron carbide layer, wherein the sensing mechanism detects changes in the boron carbide layer caused by the interception of neutrons and a monitoring device coupled to the sensing mechanics.

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Quantitative Analysis Of Nanoscale Switching In Srbi2Ta2O9 Thin Films By Piezoresponse Force Microscopy, Sergei V. Kalinin, Alexei Gruverman, Dawn Bonnell Aug 2004

Quantitative Analysis Of Nanoscale Switching In Srbi2Ta2O9 Thin Films By Piezoresponse Force Microscopy, Sergei V. Kalinin, Alexei Gruverman, Dawn Bonnell

Alexei Gruverman Publications

Local switching properties in SrBi2Ta2O9 thin films have been studied by spatially resolved piezoresponse force microscopy (PFM) and spectroscopy. Variations in PFM contrast of individual grains due to their random crystallographic orientation are consistent with the grain switching behavior examined via vertical and lateral hysteresis loops. Theoretical description of vertical hysteresis loop shape obtained in the point-charge approximation is shown to be in good agreement with the experimental data. Dependence of the hysteresis loop parameters on the grain crystallographic orientation is analyzed. It has been found that grain deviation from the ideal (010) orientation when …

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How We Think About And Prepare To Teach Physics, Dewey I. Dykstra Aug 2004

How We Think About And Prepare To Teach Physics, Dewey I. Dykstra

Physics Faculty Publications and Presentations

We have been preparing physics teachers in the same manner for many decades. Yet, physics education research reveals for some observers disturbing evidence of little or no change in understanding the phenomena occurs as a direct result of physics instruction from elementary school through the college years. The apparent compatibility between these learning results and prevailing paradigm enables the construction of a description the paradigm. If it can be demonstrated that there is even just one alternative paradigm from which powerful alternative pedagogical practice is derived, are we not obligated to change how we prepare to teach physics?

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Spectroscopic And X-Ray Crystallographic Characterization Of Bestatin Bound To The Aminopeptidase From Aeromonas (Vibrio) Proteolytica, Carin C. Stamper, David L. Bienvenue, Brian Bennett, Dagmar Ringe, Gregory A. Petsko, Richard C. Holz Aug 2004

Spectroscopic And X-Ray Crystallographic Characterization Of Bestatin Bound To The Aminopeptidase From Aeromonas (Vibrio) Proteolytica, Carin C. Stamper, David L. Bienvenue, Brian Bennett, Dagmar Ringe, Gregory A. Petsko, Richard C. Holz

Physics Faculty Research and Publications

Binding of the competitive, slow-binding inhibitor bestatin ([(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoy]-leucine) to the aminopeptidase from Aeromonas proteolytica (AAP) was examined by both spectroscopic and crystallographic methods. Electronic absorption spectra of the catalytically competent [Co_(AAP)], [CoCo(AAP)], and [ZnCo(AAP)] enzymes recorded in the presence of bestatin revealed that both of the divalent metal ions in AAP are involved in binding bestatin. The electron paramagnetic resonance (EPR) spectrum of the [CoCo(AAP)]−bestatin complex exhibited no observable perpendicular- or parallel-mode signal. These data indicate that the two CoII ions in AAP are antiferromagnetically coupled yielding an S = 0 ground state and suggest …

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Phase Shifts That Accompany Total Internal Reflection At A Dielectric–Dielectric Interface, R. M.A. Azzam Aug 2004

Phase Shifts That Accompany Total Internal Reflection At A Dielectric–Dielectric Interface, R. M.A. Azzam

Electrical Engineering Faculty Publications

The absolute, average, and differential phase shifts that p- and s-polarized light experience in total internal reflection (TIR) at the planar interface between two transparent media are considered as functions of the angle of incidence φ. Special angles at which quarter-wave phase shifts are achieved are determined as functions of the relative refractive index N. When the average phase shift equals π/2, the differential reflection phase shift Δ is maximum, and the reflection Jones matrix assumes a simple form. For N>√3, the average and differential phase shifts are equal (hence δp=3δs) at …

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High-Resolution Kinetic Energy Release Distributions And Dissociation Energies For Fullerene Ions C(N)(+), 42 <= N <= 90, K. Gluch, S. Matt-Leubner, Olof E. Echt, B. Concina, P. Scheier, T. D. Mark Aug 2004

High-Resolution Kinetic Energy Release Distributions And Dissociation Energies For Fullerene Ions C(N)(+), 42 <= N <= 90, K. Gluch, S. Matt-Leubner, Olof E. Echt, B. Concina, P. Scheier, T. D. Mark

Physics & Astronomy

We have measured the kinetic energy released in the unimolecular dissociation of fullerene ions, C(n)(+)-->C(n-2)(+)+C(2), for sizes 42less than or equal tonless than or equal to90. A three-sector-field mass spectrometer equipped with two electric sectors has been used in order to ensure that contributions from isotopomers of different masses do not distort the experimental kinetic energy release distributions. We apply the concept of microcanonical temperature to derive from these data the dissociation energies of fullerene cations. They are converted to dissociation energies of neutral fullerenes with help of published adiabatic ionization energies. The results are compared with literature values. …

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Co2+ Dissociative Recombination: A Source Of Thermal And Nonthermal C On Mars, Jane L. Fox Aug 2004

Co2+ Dissociative Recombination: A Source Of Thermal And Nonthermal C On Mars, Jane L. Fox

Physics Faculty Publications

CO2 + dissociative recombination has been assumed in the past to proceed overwhelmingly by the channel that produces CO + O. Although the channel that leads to the products C + O2 is energetically possible, the significant rearrangement of bonds that is required has led to the belief that this channel contributes minimally. Seiersen et al. [2003] have recently measured the branching ratio for the latter channel, and they have reported a value of ∼9% of the total. We have constructed both low and high solar activity models of the Martian thermosphere, and we have tested the effect …

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Test Of The Pluvinage Wave Function For The Helium Ground State, S. Jones, Joseph H. Macek, Don H. Madison Aug 2004

Test Of The Pluvinage Wave Function For The Helium Ground State, S. Jones, Joseph H. Macek, Don H. Madison

Physics Faculty Research & Creative Works

The accuracy of the Pluvinage wave function for the ground state of helium is investigated by considering a number of different physical processes including double ionization by photoabsorption, Compton scattering, and electron impact. In the high-energy limit of these processes, the accuracy of the initial ground state can be ascertained without reference to the final double-continuum state. In this limit, we find that a Hylleraas description is superior to the Pluvinage one. For intermediate energies, final-state correlation becomes important, so we employ a 3C description of the final state (the 3C wave function is the double-continuum analog of the Pluvinage …

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Approximately Self-Similar Critical Collapse In 2+1 Dimensions, Marco Cavaglia, Gerard Clement, Alessandro Fabbri Aug 2004

Approximately Self-Similar Critical Collapse In 2+1 Dimensions, Marco Cavaglia, Gerard Clement, Alessandro Fabbri

Physics Faculty Research & Creative Works

Critical collapse of a self-gravitating scalar field in a (2+1)-dimensional spacetime with negative cosmological constant seems to be dominated by a continuously self-similar solution of the field equations without cosmological constant. However, previous studies of linear perturbations in this background were inconclusive. We extend the continuously self-similar solutions to solutions of the field equations with negative cosmological constant, and analyze their linear perturbations. The extended solutions are characterized by a continuous parameter. A suitable choice of this parameter seems to improve the agreement with the numerical results. We also study the dynamics of the apparent horizon in the extended background.

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46th Rocky Mountain Conference On Analytical Chemistry Aug 2004

46th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 46th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 1-5, 2004.

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Femtosecond Spectrotemporal Magneto-Optics, J.-Y. Bigot, L. Guidoni, E. Beaurepaire, Peter N. Saeta Aug 2004

Femtosecond Spectrotemporal Magneto-Optics, J.-Y. Bigot, L. Guidoni, E. Beaurepaire, Peter N. Saeta

All HMC Faculty Publications and Research

A new method to measure and analyze the time and spectrally resolved polarimetric response of magnetic materials is presented. It allows us to study the ultrafast magnetization dynamics of a CoPt3 ferromagnetic film. The analysis of the pump-induced rotation and ellipticity detected by a broad spectrum probe beam shows that magneto-optical signals predominantly reflect the spin dynamics in ferromagnets.

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Hot Carbon Densities In The Exosphere Of Venus, Michael W. Liemohn, Jane L. Fox, Andrew F. Nagy, Xiaohua Fang Aug 2004

Hot Carbon Densities In The Exosphere Of Venus, Michael W. Liemohn, Jane L. Fox, Andrew F. Nagy, Xiaohua Fang

Physics Faculty Publications

The results of calculations of hot carbon densities in the exosphere of Venus are presented. The calculation is a two-step process. First a two-stream transport code is used to solve for the distribution function at the exobase, and then these results are used in a Liouville equation solution above the exobase. It is found that generally, photodissociation of carbon monoxide is the largest source of hot carbon atoms in the upper atmosphere of Venus, larger than dissociative recombination of CO+ and significantly larger than the creation of hot carbon through collisions with hot oxygen atoms. It is also found …

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Hopping Versus Bulk Conductivity In Transparent Oxides: 12cao - 7al₂O₃, Julia E. Medvedeva, Arthur J. Freeman Aug 2004

Hopping Versus Bulk Conductivity In Transparent Oxides: 12cao - 7al₂O₃, Julia E. Medvedeva, Arthur J. Freeman

Physics Faculty Research & Creative Works

First-principles calculations of the mayenite-based oxide, [Ca12Al14O32]2+(2e-), reveal the mechanism responsible for its high conductivity. A detailed comparison of the electronic and optical properties of this material with those of the recently discovered transparent conducting oxide, H-doped UV-activated Ca12Al14O33, allowed us to conclude that the enhanced conductivity in [Ca12Al14O32]2+(2e-) is achieved by elimination of the Coulomb blockade of the charge carriers. This results in a transition from variable range-hopping behavior with a Coulomb gap in H-doped UV-irradiated Ca …

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Neutron Multiplicity Measurements For The Afci Program Quarterly Progress Report June-August 2004, Denis Beller Aug 2004

Neutron Multiplicity Measurements For The Afci Program Quarterly Progress Report June-August 2004, Denis Beller

Transmutation Sciences Physics (TRP)

The U.S. Advanced Fuel Cycle Initiative (AFCI) is a program to develop economic and environmental methods to reduce the impact of waste from commercial nuclear fuel cycles. One concept for near-complete destruction of waste isotopes from used nuclear fuel is acceleratordriven transmutation. High-power accelerators would be used to produce high-energy charged particles, which then collide with heavy metal targets to create a cascade of neutrons. These neutrons then cause a nuclear chain reaction in subcritical systems. Fission neutrons then transmute fissile waste isotopes as well as other problematic isotopes such as technetium-99 and iodine-129. To design these systems, complex reactor …

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First Nearglobal Retrievals Of Oh Rotational Temperatures From Satellite-Based Meinel Band Emission Measurements, C. Von Savigny, C. U. Eichmann, E. J. Llewellyn, H. Bovensmann, J. P. Burrows, M. Bittner, K. Hoppner, D. Offermann, Michael J. Taylor, Y. Zhao, W. Steinbrecht, P. Winkler Aug 2004

First Nearglobal Retrievals Of Oh Rotational Temperatures From Satellite-Based Meinel Band Emission Measurements, C. Von Savigny, C. U. Eichmann, E. J. Llewellyn, H. Bovensmann, J. P. Burrows, M. Bittner, K. Hoppner, D. Offermann, Michael J. Taylor, Y. Zhao, W. Steinbrecht, P. Winkler

All Physics Faculty Publications

For the first time near-global retrievals of mesopause OH rotational temperatures from satellite-borne Meinel band emission measurements are presented. The measurements of the OH (3-1) Meinel band near 1.5 micron were performed with the SCIAMACHY instrument on the European Space Agency’s environmental satellite Envisat. The derived OH (3-1) rotational temperatures are shown to be in reasonable agreement with the CIRA (1986) atmosphere temperatures for the seasons and latitudes considered. The derived temperatures are in good agreement with groundbased measurements of the OH rotational temperature performed with a CEDAR Mesospheric Temperature Mapper (MTM) at Maui, Hawaii (21N/204E), with the GRound based …

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Erratum: Test Of The Pluvinage Wave Function For The Helium Ground State (Physical Review A - Atomic, Molecular, And Optical Physics (2004) 70 (012712)), Darryl B. Jones, Joseph H. Macek, Don H. Madison Aug 2004

Erratum: Test Of The Pluvinage Wave Function For The Helium Ground State (Physical Review A - Atomic, Molecular, And Optical Physics (2004) 70 (012712)), Darryl B. Jones, Joseph H. Macek, Don H. Madison

Physics Faculty Research & Creative Works

No abstract provided.

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Instantons In Quantum Mechanics And Resurgent Expansions, Ulrich D. Jentschura, Jean Zinn-Justin Aug 2004

Instantons In Quantum Mechanics And Resurgent Expansions, Ulrich D. Jentschura, Jean Zinn-Justin

Physics Faculty Research & Creative Works

Certain quantum mechanical potentials give rise to a vanishing perturbation series for at least one energy level (which as we here assume is the ground state), but the true ground-state energy is positive. We show here that in a typical case, the eigenvalue may be expressed in terms of a generalized perturbative expansion (resurgent expansion). Modified Bohr-Sommerfeld quantization conditions lead to generalized perturbative expansions which may be expressed in terms of nonanalytic factors of the form exp(-a/g), where a>0 is the instanton action, and power series in the coupling g, as well as logarithmic factors. The ground-state energy, for …

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Results From The Middle Atmosphere With The Rayleigh-Scatter Lidar At Usu’S Atmospheric Lidar Observatory, Vincent B. Wickwar, Joshua P. Herron, Troy A. Wynn, Eric M. Lundell Aug 2004

Results From The Middle Atmosphere With The Rayleigh-Scatter Lidar At Usu’S Atmospheric Lidar Observatory, Vincent B. Wickwar, Joshua P. Herron, Troy A. Wynn, Eric M. Lundell

Posters

No abstract provided.

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